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
 347         if (commit->object.flags & ADDED)
 348                 return;
 349         commit->object.flags |= ADDED;
 350
 351         /*
 352          * If the commit is uninteresting, don't try to
 353          * prune parents - we want the maximal uninteresting
 354          * set.
 355          *
 356          * Normally we haven't parsed the parent
 357          * yet, so we won't have a parent of a parent
 358          * here. However, it may turn out that we've
 359          * reached this commit some other way (where it
 360          * wasn't uninteresting), in which case we need
 361          * to mark its parents recursively too..
 362          */
 363         if (commit->object.flags & UNINTERESTING) {
 364                 while (parent) {
 365                         struct commit *p = parent->item;
 366                         parent = parent->next;
 367                         parse_commit(p);
 368                         p->object.flags |= UNINTERESTING;
 369                         if (p->parents)
 370                                 mark_parents_uninteresting(p);
 371                         if (p->object.flags & SEEN)
 372                                 continue;
 373                         p->object.flags |= SEEN;
 374                         insert_by_date(p, list);
 375                 }
 376                 return;
 377         }
 378
 379         /*
 380          * Ok, the commit wasn't uninteresting. Try to
 381          * simplify the commit history and find the parent
 382          * that has no differences in the path set if one exists.
 383          */
 384         if (revs->prune_fn)
 385                 revs->prune_fn(revs, commit);
 386
 387         if (revs->no_walk)
 388                 return;
 389
 390         parent = commit->parents;
 391         while (parent) {
 392                 struct commit *p = parent->item;
 393
 394                 parent = parent->next;
 395
 396                 parse_commit(p);
 397                 if (p->object.flags & SEEN)
 398                         continue;
 399                 p->object.flags |= SEEN;
 400                 insert_by_date(p, list);
 401         }
 402 }
 403
 404 static void limit_list(struct rev_info *revs)
 405 {
 406         struct commit_list *list = revs->commits;
 407         struct commit_list *newlist = NULL;
 408         struct commit_list **p = &newlist;
 409
 410         while (list) {
 411                 struct commit_list *entry = list;
 412                 struct commit *commit = list->item;
 413                 struct object *obj = &commit->object;
 414
 415                 list = list->next;
 416                 free(entry);
 417
 418                 if (revs->max_age != -1 && (commit->date < revs->max_age))
 419                         obj->flags |= UNINTERESTING;
 420                 add_parents_to_list(revs, commit, &list);
 421                 if (obj->flags & UNINTERESTING) {
 422                         mark_parents_uninteresting(commit);
 423                         if (everybody_uninteresting(list))
 424                                 break;
 425                         continue;
 426                 }
 427                 if (revs->min_age != -1 && (commit->date > revs->min_age))
 428                         continue;
 429                 p = &commit_list_insert(commit, p)->next;
 430         }
 431         if (revs->boundary) {
 432                 /* mark the ones that are on the result list first */
 433                 for (list = newlist; list; list = list->next) {
 434                         struct commit *commit = list->item;
 435                         commit->object.flags |= TMP_MARK;
 436                 }
 437                 for (list = newlist; list; list = list->next) {
 438                         struct commit *commit = list->item;
 439                         struct object *obj = &commit->object;
 440                         struct commit_list *parent;
 441                         if (obj->flags & UNINTERESTING)
 442                                 continue;
 443                         for (parent = commit->parents;
 444                              parent;
 445                              parent = parent->next) {
 446                                 struct commit *pcommit = parent->item;
 447                                 if (!(pcommit->object.flags & UNINTERESTING))
 448                                         continue;
 449                                 pcommit->object.flags |= BOUNDARY;
 450                                 if (pcommit->object.flags & TMP_MARK)
 451                                         continue;
 452                                 pcommit->object.flags |= TMP_MARK;
 453                                 p = &commit_list_insert(pcommit, p)->next;
 454                         }
 455                 }
 456                 for (list = newlist; list; list = list->next) {
 457                         struct commit *commit = list->item;
 458                         commit->object.flags &= ~TMP_MARK;
 459                 }
 460         }
 461         revs->commits = newlist;
 462 }
 463
 464 static int all_flags;
 465 static struct rev_info *all_revs;
 466
 467 static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 468 {
 469         struct object *object = get_reference(all_revs, path, sha1, all_flags);
 470         add_pending_object(all_revs, object, "");
 471         return 0;
 472 }
 473
 474 static void handle_all(struct rev_info *revs, unsigned flags)
 475 {
 476         all_revs = revs;
 477         all_flags = flags;
 478         for_each_ref(handle_one_ref, NULL);
 479 }
 480
 481 static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
 482 {
 483         unsigned char sha1[20];
 484         struct object *it;
 485         struct commit *commit;
 486         struct commit_list *parents;
 487
 488         if (*arg == '^') {
 489                 flags ^= UNINTERESTING;
 490                 arg++;
 491         }
 492         if (get_sha1(arg, sha1))
 493                 return 0;
 494         while (1) {
 495                 it = get_reference(revs, arg, sha1, 0);
 496                 if (it->type != OBJ_TAG)
 497                         break;
 498                 hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
 499         }
 500         if (it->type != OBJ_COMMIT)
 501                 return 0;
 502         commit = (struct commit *)it;
 503         for (parents = commit->parents; parents; parents = parents->next) {
 504                 it = &parents->item->object;
 505                 it->flags |= flags;
 506                 add_pending_object(revs, it, arg);
 507         }
 508         return 1;
 509 }
 510
 511 void init_revisions(struct rev_info *revs, const char *prefix)
 512 {
 513         memset(revs, 0, sizeof(*revs));
 514
 515         revs->abbrev = DEFAULT_ABBREV;
 516         revs->ignore_merges = 1;
 517         revs->simplify_history = 1;
 518         revs->pruning.recursive = 1;
 519         revs->pruning.add_remove = file_add_remove;
 520         revs->pruning.change = file_change;
 521         revs->lifo = 1;
 522         revs->dense = 1;
 523         revs->prefix = prefix;
 524         revs->max_age = -1;
 525         revs->min_age = -1;
 526         revs->max_count = -1;
 527
 528         revs->prune_fn = NULL;
 529         revs->prune_data = NULL;
 530
 531         revs->topo_setter = topo_sort_default_setter;
 532         revs->topo_getter = topo_sort_default_getter;
 533
 534         revs->commit_format = CMIT_FMT_DEFAULT;
 535
 536         diff_setup(&revs->diffopt);
 537 }
 538
 539 static void add_pending_commit_list(struct rev_info *revs,
 540                                     struct commit_list *commit_list,
 541                                     unsigned int flags)
 542 {
 543         while (commit_list) {
 544                 struct object *object = &commit_list->item->object;
 545                 object->flags |= flags;
 546                 add_pending_object(revs, object, sha1_to_hex(object->sha1));
 547                 commit_list = commit_list->next;
 548         }
 549 }
 550
 551 static void prepare_show_merge(struct rev_info *revs)
 552 {
 553         struct commit_list *bases;
 554         struct commit *head, *other;
 555         unsigned char sha1[20];
 556         const char **prune = NULL;
 557         int i, prune_num = 1; /* counting terminating NULL */
 558
 559         if (get_sha1("HEAD", sha1) || !(head = lookup_commit(sha1)))
 560                 die("--merge without HEAD?");
 561         if (get_sha1("MERGE_HEAD", sha1) || !(other = lookup_commit(sha1)))
 562                 die("--merge without MERGE_HEAD?");
 563         add_pending_object(revs, &head->object, "HEAD");
 564         add_pending_object(revs, &other->object, "MERGE_HEAD");
 565         bases = get_merge_bases(head, other, 1);
 566         while (bases) {
 567                 struct commit *it = bases->item;
 568                 struct commit_list *n = bases->next;
 569                 free(bases);
 570                 bases = n;
 571                 it->object.flags |= UNINTERESTING;
 572                 add_pending_object(revs, &it->object, "(merge-base)");
 573         }
 574
 575         if (!active_nr)
 576                 read_cache();
 577         for (i = 0; i < active_nr; i++) {
 578                 struct cache_entry *ce = active_cache[i];
 579                 if (!ce_stage(ce))
 580                         continue;
 581                 if (ce_path_match(ce, revs->prune_data)) {
 582                         prune_num++;
 583                         prune = xrealloc(prune, sizeof(*prune) * prune_num);
 584                         prune[prune_num-2] = ce->name;
 585                         prune[prune_num-1] = NULL;
 586                 }
 587                 while ((i+1 < active_nr) &&
 588                        ce_same_name(ce, active_cache[i+1]))
 589                         i++;
 590         }
 591         revs->prune_data = prune;
 592 }
 593
 594 int handle_revision_arg(const char *arg, struct rev_info *revs,
 595                         int flags,
 596                         int cant_be_filename)
 597 {
 598         char *dotdot;
 599         struct object *object;
 600         unsigned char sha1[20];
 601         int local_flags;
 602
 603         dotdot = strstr(arg, "..");
 604         if (dotdot) {
 605                 unsigned char from_sha1[20];
 606                 const char *next = dotdot + 2;
 607                 const char *this = arg;
 608                 int symmetric = *next == '.';
 609                 unsigned int flags_exclude = flags ^ UNINTERESTING;
 610
 611                 *dotdot = 0;
 612                 next += symmetric;
 613
 614                 if (!*next)
 615                         next = "HEAD";
 616                 if (dotdot == arg)
 617                         this = "HEAD";
 618                 if (!get_sha1(this, from_sha1) &&
 619                     !get_sha1(next, sha1)) {
 620                         struct commit *a, *b;
 621                         struct commit_list *exclude;
 622
 623                         a = lookup_commit_reference(from_sha1);
 624                         b = lookup_commit_reference(sha1);
 625                         if (!a || !b) {
 626                                 die(symmetric ?
 627                                     "Invalid symmetric difference expression %s...%s" :
 628                                     "Invalid revision range %s..%s",
 629                                     arg, next);
 630                         }
 631
 632                         if (!cant_be_filename) {
 633                                 *dotdot = '.';
 634                                 verify_non_filename(revs->prefix, arg);
 635                         }
 636
 637                         if (symmetric) {
 638                                 exclude = get_merge_bases(a, b, 1);
 639                                 add_pending_commit_list(revs, exclude,
 640                                                         flags_exclude);
 641                                 free_commit_list(exclude);
 642                                 a->object.flags |= flags;
 643                         } else
 644                                 a->object.flags |= flags_exclude;
 645                         b->object.flags |= flags;
 646                         add_pending_object(revs, &a->object, this);
 647                         add_pending_object(revs, &b->object, next);
 648                         return 0;
 649                 }
 650                 *dotdot = '.';
 651         }
 652         dotdot = strstr(arg, "^@");
 653         if (dotdot && !dotdot[2]) {
 654                 *dotdot = 0;
 655                 if (add_parents_only(revs, arg, flags))
 656                         return 0;
 657                 *dotdot = '^';
 658         }
 659         dotdot = strstr(arg, "^!");
 660         if (dotdot && !dotdot[2]) {
 661                 *dotdot = 0;
 662                 if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
 663                         *dotdot = '^';
 664         }
 665
 666         local_flags = 0;
 667         if (*arg == '^') {
 668                 local_flags = UNINTERESTING;
 669                 arg++;
 670         }
 671         if (get_sha1(arg, sha1))
 672                 return -1;
 673         if (!cant_be_filename)
 674                 verify_non_filename(revs->prefix, arg);
 675         object = get_reference(revs, arg, sha1, flags ^ local_flags);
 676         add_pending_object(revs, object, arg);
 677         return 0;
 678 }
 679
 680 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
 681 {
 682         if (!revs->grep_filter) {
 683                 struct grep_opt *opt = xcalloc(1, sizeof(*opt));
 684                 opt->status_only = 1;
 685                 opt->pattern_tail = &(opt->pattern_list);
 686                 opt->regflags = REG_NEWLINE;
 687                 revs->grep_filter = opt;
 688         }
 689         append_grep_pattern(revs->grep_filter, ptn,
 690                             "command line", 0, what);
 691 }
 692
 693 static void add_header_grep(struct rev_info *revs, const char *field, const char *pattern)
 694 {
 695         char *pat;
 696         const char *prefix;
 697         int patlen, fldlen;
 698
 699         fldlen = strlen(field);
 700         patlen = strlen(pattern);
 701         pat = xmalloc(patlen + fldlen + 10);
 702         prefix = ".*";
 703         if (*pattern == '^') {
 704                 prefix = "";
 705                 pattern++;
 706         }
 707         sprintf(pat, "^%s %s%s", field, prefix, pattern);
 708         add_grep(revs, pat, GREP_PATTERN_HEAD);
 709 }
 710
 711 static void add_message_grep(struct rev_info *revs, const char *pattern)
 712 {
 713         add_grep(revs, pattern, GREP_PATTERN_BODY);
 714 }
 715
 716 static void add_ignore_packed(struct rev_info *revs, const char *name)
 717 {
 718         int num = ++revs->num_ignore_packed;
 719
 720         revs->ignore_packed = xrealloc(revs->ignore_packed,
 721                                        sizeof(const char **) * (num + 1));
 722         revs->ignore_packed[num-1] = name;
 723         revs->ignore_packed[num] = NULL;
 724 }
 725
 726 /*
 727  * Parse revision information, filling in the "rev_info" structure,
 728  * and removing the used arguments from the argument list.
 729  *
 730  * Returns the number of arguments left that weren't recognized
 731  * (which are also moved to the head of the argument list)
 732  */
 733 int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
 734 {
 735         int i, flags, seen_dashdash, show_merge;
 736         const char **unrecognized = argv + 1;
 737         int left = 1;
 738         int all_match = 0;
 739
 740         /* First, search for "--" */
 741         seen_dashdash = 0;
 742         for (i = 1; i < argc; i++) {
 743                 const char *arg = argv[i];
 744                 if (strcmp(arg, "--"))
 745                         continue;
 746                 argv[i] = NULL;
 747                 argc = i;
 748                 revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
 749                 seen_dashdash = 1;
 750                 break;
 751         }
 752
 753         flags = show_merge = 0;
 754         for (i = 1; i < argc; i++) {
 755                 const char *arg = argv[i];
 756                 if (*arg == '-') {
 757                         int opts;
 758                         if (!strncmp(arg, "--max-count=", 12)) {
 759                                 revs->max_count = atoi(arg + 12);
 760                                 continue;
 761                         }
 762                         /* accept -<digit>, like traditional "head" */
 763                         if ((*arg == '-') && isdigit(arg[1])) {
 764                                 revs->max_count = atoi(arg + 1);
 765                                 continue;
 766                         }
 767                         if (!strcmp(arg, "-n")) {
 768                                 if (argc <= i + 1)
 769                                         die("-n requires an argument");
 770                                 revs->max_count = atoi(argv[++i]);
 771                                 continue;
 772                         }
 773                         if (!strncmp(arg,"-n",2)) {
 774                                 revs->max_count = atoi(arg + 2);
 775                                 continue;
 776                         }
 777                         if (!strncmp(arg, "--max-age=", 10)) {
 778                                 revs->max_age = atoi(arg + 10);
 779                                 continue;
 780                         }
 781                         if (!strncmp(arg, "--since=", 8)) {
 782                                 revs->max_age = approxidate(arg + 8);
 783                                 continue;
 784                         }
 785                         if (!strncmp(arg, "--after=", 8)) {
 786                                 revs->max_age = approxidate(arg + 8);
 787                                 continue;
 788                         }
 789                         if (!strncmp(arg, "--min-age=", 10)) {
 790                                 revs->min_age = atoi(arg + 10);
 791                                 continue;
 792                         }
 793                         if (!strncmp(arg, "--before=", 9)) {
 794                                 revs->min_age = approxidate(arg + 9);
 795                                 continue;
 796                         }
 797                         if (!strncmp(arg, "--until=", 8)) {
 798                                 revs->min_age = approxidate(arg + 8);
 799                                 continue;
 800                         }
 801                         if (!strcmp(arg, "--all")) {
 802                                 handle_all(revs, flags);
 803                                 continue;
 804                         }
 805                         if (!strcmp(arg, "--not")) {
 806                                 flags ^= UNINTERESTING;
 807                                 continue;
 808                         }
 809                         if (!strcmp(arg, "--default")) {
 810                                 if (++i >= argc)
 811                                         die("bad --default argument");
 812                                 def = argv[i];
 813                                 continue;
 814                         }
 815                         if (!strcmp(arg, "--merge")) {
 816                                 show_merge = 1;
 817                                 continue;
 818                         }
 819                         if (!strcmp(arg, "--topo-order")) {
 820                                 revs->topo_order = 1;
 821                                 continue;
 822                         }
 823                         if (!strcmp(arg, "--date-order")) {
 824                                 revs->lifo = 0;
 825                                 revs->topo_order = 1;
 826                                 continue;
 827                         }
 828                         if (!strcmp(arg, "--parents")) {
 829                                 revs->parents = 1;
 830                                 continue;
 831                         }
 832                         if (!strcmp(arg, "--dense")) {
 833                                 revs->dense = 1;
 834                                 continue;
 835                         }
 836                         if (!strcmp(arg, "--sparse")) {
 837                                 revs->dense = 0;
 838                                 continue;
 839                         }
 840                         if (!strcmp(arg, "--remove-empty")) {
 841                                 revs->remove_empty_trees = 1;
 842                                 continue;
 843                         }
 844                         if (!strcmp(arg, "--no-merges")) {
 845                                 revs->no_merges = 1;
 846                                 continue;
 847                         }
 848                         if (!strcmp(arg, "--boundary")) {
 849                                 revs->boundary = 1;
 850                                 continue;
 851                         }
 852                         if (!strcmp(arg, "--objects")) {
 853                                 revs->tag_objects = 1;
 854                                 revs->tree_objects = 1;
 855                                 revs->blob_objects = 1;
 856                                 continue;
 857                         }
 858                         if (!strcmp(arg, "--objects-edge")) {
 859                                 revs->tag_objects = 1;
 860                                 revs->tree_objects = 1;
 861                                 revs->blob_objects = 1;
 862                                 revs->edge_hint = 1;
 863                                 continue;
 864                         }
 865                         if (!strcmp(arg, "--unpacked")) {
 866                                 revs->unpacked = 1;
 867                                 free(revs->ignore_packed);
 868                                 revs->ignore_packed = NULL;
 869                                 revs->num_ignore_packed = 0;
 870                                 continue;
 871                         }
 872                         if (!strncmp(arg, "--unpacked=", 11)) {
 873                                 revs->unpacked = 1;
 874                                 add_ignore_packed(revs, arg+11);
 875                                 continue;
 876                         }
 877                         if (!strcmp(arg, "-r")) {
 878                                 revs->diff = 1;
 879                                 revs->diffopt.recursive = 1;
 880                                 continue;
 881                         }
 882                         if (!strcmp(arg, "-t")) {
 883                                 revs->diff = 1;
 884                                 revs->diffopt.recursive = 1;
 885                                 revs->diffopt.tree_in_recursive = 1;
 886                                 continue;
 887                         }
 888                         if (!strcmp(arg, "-m")) {
 889                                 revs->ignore_merges = 0;
 890                                 continue;
 891                         }
 892                         if (!strcmp(arg, "-c")) {
 893                                 revs->diff = 1;
 894                                 revs->dense_combined_merges = 0;
 895                                 revs->combine_merges = 1;
 896                                 continue;
 897                         }
 898                         if (!strcmp(arg, "--cc")) {
 899                                 revs->diff = 1;
 900                                 revs->dense_combined_merges = 1;
 901                                 revs->combine_merges = 1;
 902                                 continue;
 903                         }
 904                         if (!strcmp(arg, "-v")) {
 905                                 revs->verbose_header = 1;
 906                                 continue;
 907                         }
 908                         if (!strncmp(arg, "--pretty", 8)) {
 909                                 revs->verbose_header = 1;
 910                                 revs->commit_format = get_commit_format(arg+8);
 911                                 continue;
 912                         }
 913                         if (!strcmp(arg, "--root")) {
 914                                 revs->show_root_diff = 1;
 915                                 continue;
 916                         }
 917                         if (!strcmp(arg, "--no-commit-id")) {
 918                                 revs->no_commit_id = 1;
 919                                 continue;
 920                         }
 921                         if (!strcmp(arg, "--always")) {
 922                                 revs->always_show_header = 1;
 923                                 continue;
 924                         }
 925                         if (!strcmp(arg, "--no-abbrev")) {
 926                                 revs->abbrev = 0;
 927                                 continue;
 928                         }
 929                         if (!strcmp(arg, "--abbrev")) {
 930                                 revs->abbrev = DEFAULT_ABBREV;
 931                                 continue;
 932                         }
 933                         if (!strncmp(arg, "--abbrev=", 9)) {
 934                                 revs->abbrev = strtoul(arg + 9, NULL, 10);
 935                                 if (revs->abbrev < MINIMUM_ABBREV)
 936                                         revs->abbrev = MINIMUM_ABBREV;
 937                                 else if (revs->abbrev > 40)
 938                                         revs->abbrev = 40;
 939                                 continue;
 940                         }
 941                         if (!strcmp(arg, "--abbrev-commit")) {
 942                                 revs->abbrev_commit = 1;
 943                                 continue;
 944                         }
 945                         if (!strcmp(arg, "--full-diff")) {
 946                                 revs->diff = 1;
 947                                 revs->full_diff = 1;
 948                                 continue;
 949                         }
 950                         if (!strcmp(arg, "--full-history")) {
 951                                 revs->simplify_history = 0;
 952                                 continue;
 953                         }
 954                         if (!strcmp(arg, "--relative-date")) {
 955                                 revs->relative_date = 1;
 956                                 continue;
 957                         }
 958
 959                         /*
 960                          * Grepping the commit log
 961                          */
 962                         if (!strncmp(arg, "--author=", 9)) {
 963                                 add_header_grep(revs, "author", arg+9);
 964                                 continue;
 965                         }
 966                         if (!strncmp(arg, "--committer=", 12)) {
 967                                 add_header_grep(revs, "committer", arg+12);
 968                                 continue;
 969                         }
 970                         if (!strncmp(arg, "--grep=", 7)) {
 971                                 add_message_grep(revs, arg+7);
 972                                 continue;
 973                         }
 974                         if (!strcmp(arg, "--all-match")) {
 975                                 all_match = 1;
 976                                 continue;
 977                         }
 978
 979                         opts = diff_opt_parse(&revs->diffopt, argv+i, argc-i);
 980                         if (opts > 0) {
 981                                 revs->diff = 1;
 982                                 i += opts - 1;
 983                                 continue;
 984                         }
 985                         *unrecognized++ = arg;
 986                         left++;
 987                         continue;
 988                 }
 989
 990                 if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
 991                         int j;
 992                         if (seen_dashdash || *arg == '^')
 993                                 die("bad revision '%s'", arg);
 994
 995                         /* If we didn't have a "--":
 996                          * (1) all filenames must exist;
 997                          * (2) all rev-args must not be interpretable
 998                          *     as a valid filename.
 999                          * but the latter we have checked in the main loop.
1000                          */
1001                         for (j = i; j < argc; j++)
1002                                 verify_filename(revs->prefix, argv[j]);
1003
1004                         revs->prune_data = get_pathspec(revs->prefix,
1005                                                         argv + i);
1006                         break;
1007                 }
1008         }
1009
1010         if (show_merge)
1011                 prepare_show_merge(revs);
1012         if (def && !revs->pending.nr) {
1013                 unsigned char sha1[20];
1014                 struct object *object;
1015                 if (get_sha1(def, sha1))
1016                         die("bad default revision '%s'", def);
1017                 object = get_reference(revs, def, sha1, 0);
1018                 add_pending_object(revs, object, def);
1019         }
1020
1021         if (revs->topo_order)
1022                 revs->limited = 1;
1023
1024         if (revs->prune_data) {
1025                 diff_tree_setup_paths(revs->prune_data, &revs->pruning);
1026                 revs->prune_fn = try_to_simplify_commit;
1027                 if (!revs->full_diff)
1028                         diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
1029         }
1030         if (revs->combine_merges) {
1031                 revs->ignore_merges = 0;
1032                 if (revs->dense_combined_merges && !revs->diffopt.output_format)
1033                         revs->diffopt.output_format = DIFF_FORMAT_PATCH;
1034         }
1035         revs->diffopt.abbrev = revs->abbrev;
1036         if (diff_setup_done(&revs->diffopt) < 0)
1037                 die("diff_setup_done failed");
1038
1039         if (revs->grep_filter) {
1040                 revs->grep_filter->all_match = all_match;
1041                 compile_grep_patterns(revs->grep_filter);
1042         }
1043
1044         return left;
1045 }
1046
1047 void prepare_revision_walk(struct rev_info *revs)
1048 {
1049         int nr = revs->pending.nr;
1050         struct object_array_entry *list = revs->pending.objects;
1051
1052         revs->pending.nr = 0;
1053         revs->pending.alloc = 0;
1054         revs->pending.objects = NULL;
1055         while (--nr >= 0) {
1056                 struct commit *commit = handle_commit(revs, list->item, list->name);
1057                 if (commit) {
1058                         if (!(commit->object.flags & SEEN)) {
1059                                 commit->object.flags |= SEEN;
1060                                 insert_by_date(commit, &revs->commits);
1061                         }
1062                 }
1063                 list++;
1064         }
1065
1066         if (revs->no_walk)
1067                 return;
1068         if (revs->limited)
1069                 limit_list(revs);
1070         if (revs->topo_order)
1071                 sort_in_topological_order_fn(&revs->commits, revs->lifo,
1072                                              revs->topo_setter,
1073                                              revs->topo_getter);
1074 }
1075
1076 static int rewrite_one(struct rev_info *revs, struct commit **pp)
1077 {
1078         for (;;) {
1079                 struct commit *p = *pp;
1080                 if (!revs->limited)
1081                         add_parents_to_list(revs, p, &revs->commits);
1082                 if (p->parents && p->parents->next)
1083                         return 0;
1084                 if (p->object.flags & (TREECHANGE | UNINTERESTING))
1085                         return 0;
1086                 if (!p->parents)
1087                         return -1;
1088                 *pp = p->parents->item;
1089         }
1090 }
1091
1092 static void rewrite_parents(struct rev_info *revs, struct commit *commit)
1093 {
1094         struct commit_list **pp = &commit->parents;
1095         while (*pp) {
1096                 struct commit_list *parent = *pp;
1097                 if (rewrite_one(revs, &parent->item) < 0) {
1098                         *pp = parent->next;
1099                         continue;
1100                 }
1101                 pp = &parent->next;
1102         }
1103 }
1104
1105 static void mark_boundary_to_show(struct commit *commit)
1106 {
1107         struct commit_list *p = commit->parents;
1108         while (p) {
1109                 commit = p->item;
1110                 p = p->next;
1111                 if (commit->object.flags & BOUNDARY)
1112                         commit->object.flags |= BOUNDARY_SHOW;
1113         }
1114 }
1115
1116 static int commit_match(struct commit *commit, struct rev_info *opt)
1117 {
1118         if (!opt->grep_filter)
1119                 return 1;
1120         return grep_buffer(opt->grep_filter,
1121                            NULL, /* we say nothing, not even filename */
1122                            commit->buffer, strlen(commit->buffer));
1123 }
1124
1125 struct commit *get_revision(struct rev_info *revs)
1126 {
1127         struct commit_list *list = revs->commits;
1128
1129         if (!list)
1130                 return NULL;
1131
1132         /* Check the max_count ... */
1133         switch (revs->max_count) {
1134         case -1:
1135                 break;
1136         case 0:
1137                 return NULL;
1138         default:
1139                 revs->max_count--;
1140         }
1141
1142         do {
1143                 struct commit_list *entry = revs->commits;
1144                 struct commit *commit = entry->item;
1145
1146                 revs->commits = entry->next;
1147                 free(entry);
1148
1149                 /*
1150                  * If we haven't done the list limiting, we need to look at
1151                  * the parents here. We also need to do the date-based limiting
1152                  * that we'd otherwise have done in limit_list().
1153                  */
1154                 if (!revs->limited) {
1155                         if (revs->max_age != -1 &&
1156                             (commit->date < revs->max_age))
1157                                 continue;
1158                         add_parents_to_list(revs, commit, &revs->commits);
1159                 }
1160                 if (commit->object.flags & SHOWN)
1161                         continue;
1162
1163                 if (revs->unpacked && has_sha1_pack(commit->object.sha1,
1164                                                     revs->ignore_packed))
1165                     continue;
1166
1167                 /* We want to show boundary commits only when their
1168                  * children are shown.  When path-limiter is in effect,
1169                  * rewrite_parents() drops some commits from getting shown,
1170                  * and there is no point showing boundary parents that
1171                  * are not shown.  After rewrite_parents() rewrites the
1172                  * parents of a commit that is shown, we mark the boundary
1173                  * parents with BOUNDARY_SHOW.
1174                  */
1175                 if (commit->object.flags & BOUNDARY_SHOW) {
1176                         commit->object.flags |= SHOWN;
1177                         return commit;
1178                 }
1179                 if (commit->object.flags & UNINTERESTING)
1180                         continue;
1181                 if (revs->min_age != -1 && (commit->date > revs->min_age))
1182                         continue;
1183                 if (revs->no_merges &&
1184                     commit->parents && commit->parents->next)
1185                         continue;
1186                 if (!commit_match(commit, revs))
1187                         continue;
1188                 if (revs->prune_fn && revs->dense) {
1189                         /* Commit without changes? */
1190                         if (!(commit->object.flags & TREECHANGE)) {
1191                                 /* drop merges unless we want parenthood */
1192                                 if (!revs->parents)
1193                                         continue;
1194                                 /* non-merge - always ignore it */
1195                                 if (!commit->parents || !commit->parents->next)
1196                                         continue;
1197                         }
1198                         if (revs->parents)
1199                                 rewrite_parents(revs, commit);
1200                 }
1201                 if (revs->boundary)
1202                         mark_boundary_to_show(commit);
1203                 commit->object.flags |= SHOWN;
1204                 return commit;
1205         } while (revs->commits);
1206         return NULL;
1207 }