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 "graph.h"
  10 #include "grep.h"
  11 #include "reflog-walk.h"
  12 #include "patch-ids.h"
  13 #include "decorate.h"
  14
  15 volatile show_early_output_fn_t show_early_output;
  16
  17 static char *path_name(struct name_path *path, const char *name)
  18 {
  19         struct name_path *p;
  20         char *n, *m;
  21         int nlen = strlen(name);
  22         int len = nlen + 1;
  23
  24         for (p = path; p; p = p->up) {
  25                 if (p->elem_len)
  26                         len += p->elem_len + 1;
  27         }
  28         n = xmalloc(len);
  29         m = n + len - (nlen + 1);
  30         strcpy(m, name);
  31         for (p = path; p; p = p->up) {
  32                 if (p->elem_len) {
  33                         m -= p->elem_len + 1;
  34                         memcpy(m, p->elem, p->elem_len);
  35                         m[p->elem_len] = '/';
  36                 }
  37         }
  38         return n;
  39 }
  40
  41 void add_object(struct object *obj,
  42                 struct object_array *p,
  43                 struct name_path *path,
  44                 const char *name)
  45 {
  46         add_object_array(obj, path_name(path, name), p);
  47 }
  48
  49 static void mark_blob_uninteresting(struct blob *blob)
  50 {
  51         if (!blob)
  52                 return;
  53         if (blob->object.flags & UNINTERESTING)
  54                 return;
  55         blob->object.flags |= UNINTERESTING;
  56 }
  57
  58 void mark_tree_uninteresting(struct tree *tree)
  59 {
  60         struct tree_desc desc;
  61         struct name_entry entry;
  62         struct object *obj = &tree->object;
  63
  64         if (!tree)
  65                 return;
  66         if (obj->flags & UNINTERESTING)
  67                 return;
  68         obj->flags |= UNINTERESTING;
  69         if (!has_sha1_file(obj->sha1))
  70                 return;
  71         if (parse_tree(tree) < 0)
  72                 die("bad tree %s", sha1_to_hex(obj->sha1));
  73
  74         init_tree_desc(&desc, tree->buffer, tree->size);
  75         while (tree_entry(&desc, &entry)) {
  76                 switch (object_type(entry.mode)) {
  77                 case OBJ_TREE:
  78                         mark_tree_uninteresting(lookup_tree(entry.sha1));
  79                         break;
  80                 case OBJ_BLOB:
  81                         mark_blob_uninteresting(lookup_blob(entry.sha1));
  82                         break;
  83                 default:
  84                         /* Subproject commit - not in this repository */
  85                         break;
  86                 }
  87         }
  88
  89         /*
  90          * We don't care about the tree any more
  91          * after it has been marked uninteresting.
  92          */
  93         free(tree->buffer);
  94         tree->buffer = NULL;
  95 }
  96
  97 void mark_parents_uninteresting(struct commit *commit)
  98 {
  99         struct commit_list *parents = commit->parents;
 100
 101         while (parents) {
 102                 struct commit *commit = parents->item;
 103                 if (!(commit->object.flags & UNINTERESTING)) {
 104                         commit->object.flags |= UNINTERESTING;
 105
 106                         /*
 107                          * Normally we haven't parsed the parent
 108                          * yet, so we won't have a parent of a parent
 109                          * here. However, it may turn out that we've
 110                          * reached this commit some other way (where it
 111                          * wasn't uninteresting), in which case we need
 112                          * to mark its parents recursively too..
 113                          */
 114                         if (commit->parents)
 115                                 mark_parents_uninteresting(commit);
 116                 }
 117
 118                 /*
 119                  * A missing commit is ok iff its parent is marked
 120                  * uninteresting.
 121                  *
 122                  * We just mark such a thing parsed, so that when
 123                  * it is popped next time around, we won't be trying
 124                  * to parse it and get an error.
 125                  */
 126                 if (!has_sha1_file(commit->object.sha1))
 127                         commit->object.parsed = 1;
 128                 parents = parents->next;
 129         }
 130 }
 131
 132 static void add_pending_object_with_mode(struct rev_info *revs, struct object *obj, const char *name, unsigned mode)
 133 {
 134         if (revs->no_walk && (obj->flags & UNINTERESTING))
 135                 die("object ranges do not make sense when not walking revisions");
 136         if (revs->reflog_info && obj->type == OBJ_COMMIT &&
 137                         add_reflog_for_walk(revs->reflog_info,
 138                                 (struct commit *)obj, name))
 139                 return;
 140         add_object_array_with_mode(obj, name, &revs->pending, mode);
 141 }
 142
 143 void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
 144 {
 145         add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
 146 }
 147
 148 void add_head_to_pending(struct rev_info *revs)
 149 {
 150         unsigned char sha1[20];
 151         struct object *obj;
 152         if (get_sha1("HEAD", sha1))
 153                 return;
 154         obj = parse_object(sha1);
 155         if (!obj)
 156                 return;
 157         add_pending_object(revs, obj, "HEAD");
 158 }
 159
 160 static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
 161 {
 162         struct object *object;
 163
 164         object = parse_object(sha1);
 165         if (!object)
 166                 die("bad object %s", name);
 167         object->flags |= flags;
 168         return object;
 169 }
 170
 171 static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
 172 {
 173         unsigned long flags = object->flags;
 174
 175         /*
 176          * Tag object? Look what it points to..
 177          */
 178         while (object->type == OBJ_TAG) {
 179                 struct tag *tag = (struct tag *) object;
 180                 if (revs->tag_objects && !(flags & UNINTERESTING))
 181                         add_pending_object(revs, object, tag->tag);
 182                 if (!tag->tagged)
 183                         die("bad tag");
 184                 object = parse_object(tag->tagged->sha1);
 185                 if (!object)
 186                         die("bad object %s", sha1_to_hex(tag->tagged->sha1));
 187         }
 188
 189         /*
 190          * Commit object? Just return it, we'll do all the complex
 191          * reachability crud.
 192          */
 193         if (object->type == OBJ_COMMIT) {
 194                 struct commit *commit = (struct commit *)object;
 195                 if (parse_commit(commit) < 0)
 196                         die("unable to parse commit %s", name);
 197                 if (flags & UNINTERESTING) {
 198                         commit->object.flags |= UNINTERESTING;
 199                         mark_parents_uninteresting(commit);
 200                         revs->limited = 1;
 201                 }
 202                 return commit;
 203         }
 204
 205         /*
 206          * Tree object? Either mark it uniniteresting, or add it
 207          * to the list of objects to look at later..
 208          */
 209         if (object->type == OBJ_TREE) {
 210                 struct tree *tree = (struct tree *)object;
 211                 if (!revs->tree_objects)
 212                         return NULL;
 213                 if (flags & UNINTERESTING) {
 214                         mark_tree_uninteresting(tree);
 215                         return NULL;
 216                 }
 217                 add_pending_object(revs, object, "");
 218                 return NULL;
 219         }
 220
 221         /*
 222          * Blob object? You know the drill by now..
 223          */
 224         if (object->type == OBJ_BLOB) {
 225                 struct blob *blob = (struct blob *)object;
 226                 if (!revs->blob_objects)
 227                         return NULL;
 228                 if (flags & UNINTERESTING) {
 229                         mark_blob_uninteresting(blob);
 230                         return NULL;
 231                 }
 232                 add_pending_object(revs, object, "");
 233                 return NULL;
 234         }
 235         die("%s is unknown object", name);
 236 }
 237
 238 static int everybody_uninteresting(struct commit_list *orig)
 239 {
 240         struct commit_list *list = orig;
 241         while (list) {
 242                 struct commit *commit = list->item;
 243                 list = list->next;
 244                 if (commit->object.flags & UNINTERESTING)
 245                         continue;
 246                 return 0;
 247         }
 248         return 1;
 249 }
 250
 251 /*
 252  * The goal is to get REV_TREE_NEW as the result only if the
 253  * diff consists of all '+' (and no other changes), and
 254  * REV_TREE_DIFFERENT otherwise (of course if the trees are
 255  * the same we want REV_TREE_SAME).  That means that once we
 256  * get to REV_TREE_DIFFERENT, we do not have to look any further.
 257  */
 258 static int tree_difference = REV_TREE_SAME;
 259
 260 static void file_add_remove(struct diff_options *options,
 261                     int addremove, unsigned mode,
 262                     const unsigned char *sha1,
 263                     const char *fullpath)
 264 {
 265         int diff = REV_TREE_DIFFERENT;
 266
 267         /*
 268          * Is it an add of a new file? It means that the old tree
 269          * didn't have it at all, so we will turn "REV_TREE_SAME" ->
 270          * "REV_TREE_NEW", but leave any "REV_TREE_DIFFERENT" alone
 271          * (and if it already was "REV_TREE_NEW", we'll keep it
 272          * "REV_TREE_NEW" of course).
 273          */
 274         if (addremove == '+') {
 275                 diff = tree_difference;
 276                 if (diff != REV_TREE_SAME)
 277                         return;
 278                 diff = REV_TREE_NEW;
 279         }
 280         tree_difference = diff;
 281         if (tree_difference == REV_TREE_DIFFERENT)
 282                 DIFF_OPT_SET(options, HAS_CHANGES);
 283 }
 284
 285 static void file_change(struct diff_options *options,
 286                  unsigned old_mode, unsigned new_mode,
 287                  const unsigned char *old_sha1,
 288                  const unsigned char *new_sha1,
 289                  const char *fullpath)
 290 {
 291         tree_difference = REV_TREE_DIFFERENT;
 292         DIFF_OPT_SET(options, HAS_CHANGES);
 293 }
 294
 295 static int rev_compare_tree(struct rev_info *revs, struct tree *t1, struct tree *t2)
 296 {
 297         if (!t1)
 298                 return REV_TREE_NEW;
 299         if (!t2)
 300                 return REV_TREE_DIFFERENT;
 301         tree_difference = REV_TREE_SAME;
 302         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 303         if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
 304                            &revs->pruning) < 0)
 305                 return REV_TREE_DIFFERENT;
 306         return tree_difference;
 307 }
 308
 309 static int rev_same_tree_as_empty(struct rev_info *revs, struct tree *t1)
 310 {
 311         int retval;
 312         void *tree;
 313         unsigned long size;
 314         struct tree_desc empty, real;
 315
 316         if (!t1)
 317                 return 0;
 318
 319         tree = read_object_with_reference(t1->object.sha1, tree_type, &size, NULL);
 320         if (!tree)
 321                 return 0;
 322         init_tree_desc(&real, tree, size);
 323         init_tree_desc(&empty, "", 0);
 324
 325         tree_difference = REV_TREE_SAME;
 326         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 327         retval = diff_tree(&empty, &real, "", &revs->pruning);
 328         free(tree);
 329
 330         return retval >= 0 && (tree_difference == REV_TREE_SAME);
 331 }
 332
 333 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 334 {
 335         struct commit_list **pp, *parent;
 336         int tree_changed = 0, tree_same = 0;
 337
 338         /*
 339          * If we don't do pruning, everything is interesting
 340          */
 341         if (!revs->prune)
 342                 return;
 343
 344         if (!commit->tree)
 345                 return;
 346
 347         if (!commit->parents) {
 348                 if (rev_same_tree_as_empty(revs, commit->tree))
 349                         commit->object.flags |= TREESAME;
 350                 return;
 351         }
 352
 353         /*
 354          * Normal non-merge commit? If we don't want to make the
 355          * history dense, we consider it always to be a change..
 356          */
 357         if (!revs->dense && !commit->parents->next)
 358                 return;
 359
 360         pp = &commit->parents;
 361         while ((parent = *pp) != NULL) {
 362                 struct commit *p = parent->item;
 363
 364                 if (parse_commit(p) < 0)
 365                         die("cannot simplify commit %s (because of %s)",
 366                             sha1_to_hex(commit->object.sha1),
 367                             sha1_to_hex(p->object.sha1));
 368                 switch (rev_compare_tree(revs, p->tree, commit->tree)) {
 369                 case REV_TREE_SAME:
 370                         tree_same = 1;
 371                         if (!revs->simplify_history || (p->object.flags & UNINTERESTING)) {
 372                                 /* Even if a merge with an uninteresting
 373                                  * side branch brought the entire change
 374                                  * we are interested in, we do not want
 375                                  * to lose the other branches of this
 376                                  * merge, so we just keep going.
 377                                  */
 378                                 pp = &parent->next;
 379                                 continue;
 380                         }
 381                         parent->next = NULL;
 382                         commit->parents = parent;
 383                         commit->object.flags |= TREESAME;
 384                         return;
 385
 386                 case REV_TREE_NEW:
 387                         if (revs->remove_empty_trees &&
 388                             rev_same_tree_as_empty(revs, p->tree)) {
 389                                 /* We are adding all the specified
 390                                  * paths from this parent, so the
 391                                  * history beyond this parent is not
 392                                  * interesting.  Remove its parents
 393                                  * (they are grandparents for us).
 394                                  * IOW, we pretend this parent is a
 395                                  * "root" commit.
 396                                  */
 397                                 if (parse_commit(p) < 0)
 398                                         die("cannot simplify commit %s (invalid %s)",
 399                                             sha1_to_hex(commit->object.sha1),
 400                                             sha1_to_hex(p->object.sha1));
 401                                 p->parents = NULL;
 402                         }
 403                 /* fallthrough */
 404                 case REV_TREE_DIFFERENT:
 405                         tree_changed = 1;
 406                         pp = &parent->next;
 407                         continue;
 408                 }
 409                 die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
 410         }
 411         if (tree_changed && !tree_same)
 412                 return;
 413         commit->object.flags |= TREESAME;
 414 }
 415
 416 static void insert_by_date_cached(struct commit *p, struct commit_list **head,
 417                     struct commit_list *cached_base, struct commit_list **cache)
 418 {
 419         struct commit_list *new_entry;
 420
 421         if (cached_base && p->date < cached_base->item->date)
 422                 new_entry = insert_by_date(p, &cached_base->next);
 423         else
 424                 new_entry = insert_by_date(p, head);
 425
 426         if (cache && (!*cache || p->date < (*cache)->item->date))
 427                 *cache = new_entry;
 428 }
 429
 430 static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
 431                     struct commit_list **list, struct commit_list **cache_ptr)
 432 {
 433         struct commit_list *parent = commit->parents;
 434         unsigned left_flag;
 435         struct commit_list *cached_base = cache_ptr ? *cache_ptr : NULL;
 436
 437         if (commit->object.flags & ADDED)
 438                 return 0;
 439         commit->object.flags |= ADDED;
 440
 441         /*
 442          * If the commit is uninteresting, don't try to
 443          * prune parents - we want the maximal uninteresting
 444          * set.
 445          *
 446          * Normally we haven't parsed the parent
 447          * yet, so we won't have a parent of a parent
 448          * here. However, it may turn out that we've
 449          * reached this commit some other way (where it
 450          * wasn't uninteresting), in which case we need
 451          * to mark its parents recursively too..
 452          */
 453         if (commit->object.flags & UNINTERESTING) {
 454                 while (parent) {
 455                         struct commit *p = parent->item;
 456                         parent = parent->next;
 457                         if (parse_commit(p) < 0)
 458                                 return -1;
 459                         p->object.flags |= UNINTERESTING;
 460                         if (p->parents)
 461                                 mark_parents_uninteresting(p);
 462                         if (p->object.flags & SEEN)
 463                                 continue;
 464                         p->object.flags |= SEEN;
 465                         insert_by_date_cached(p, list, cached_base, cache_ptr);
 466                 }
 467                 return 0;
 468         }
 469
 470         /*
 471          * Ok, the commit wasn't uninteresting. Try to
 472          * simplify the commit history and find the parent
 473          * that has no differences in the path set if one exists.
 474          */
 475         try_to_simplify_commit(revs, commit);
 476
 477         if (revs->no_walk)
 478                 return 0;
 479
 480         left_flag = (commit->object.flags & SYMMETRIC_LEFT);
 481
 482         for (parent = commit->parents; parent; parent = parent->next) {
 483                 struct commit *p = parent->item;
 484
 485                 if (parse_commit(p) < 0)
 486                         return -1;
 487                 p->object.flags |= left_flag;
 488                 if (!(p->object.flags & SEEN)) {
 489                         p->object.flags |= SEEN;
 490                         insert_by_date_cached(p, list, cached_base, cache_ptr);
 491                 }
 492                 if(revs->first_parent_only)
 493                         break;
 494         }
 495         return 0;
 496 }
 497
 498 static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
 499 {
 500         struct commit_list *p;
 501         int left_count = 0, right_count = 0;
 502         int left_first;
 503         struct patch_ids ids;
 504
 505         /* First count the commits on the left and on the right */
 506         for (p = list; p; p = p->next) {
 507                 struct commit *commit = p->item;
 508                 unsigned flags = commit->object.flags;
 509                 if (flags & BOUNDARY)
 510                         ;
 511                 else if (flags & SYMMETRIC_LEFT)
 512                         left_count++;
 513                 else
 514                         right_count++;
 515         }
 516
 517         if (!left_count || !right_count)
 518                 return;
 519
 520         left_first = left_count < right_count;
 521         init_patch_ids(&ids);
 522         if (revs->diffopt.nr_paths) {
 523                 ids.diffopts.nr_paths = revs->diffopt.nr_paths;
 524                 ids.diffopts.paths = revs->diffopt.paths;
 525                 ids.diffopts.pathlens = revs->diffopt.pathlens;
 526         }
 527
 528         /* Compute patch-ids for one side */
 529         for (p = list; p; p = p->next) {
 530                 struct commit *commit = p->item;
 531                 unsigned flags = commit->object.flags;
 532
 533                 if (flags & BOUNDARY)
 534                         continue;
 535                 /*
 536                  * If we have fewer left, left_first is set and we omit
 537                  * commits on the right branch in this loop.  If we have
 538                  * fewer right, we skip the left ones.
 539                  */
 540                 if (left_first != !!(flags & SYMMETRIC_LEFT))
 541                         continue;
 542                 commit->util = add_commit_patch_id(commit, &ids);
 543         }
 544
 545         /* Check the other side */
 546         for (p = list; p; p = p->next) {
 547                 struct commit *commit = p->item;
 548                 struct patch_id *id;
 549                 unsigned flags = commit->object.flags;
 550
 551                 if (flags & BOUNDARY)
 552                         continue;
 553                 /*
 554                  * If we have fewer left, left_first is set and we omit
 555                  * commits on the left branch in this loop.
 556                  */
 557                 if (left_first == !!(flags & SYMMETRIC_LEFT))
 558                         continue;
 559
 560                 /*
 561                  * Have we seen the same patch id?
 562                  */
 563                 id = has_commit_patch_id(commit, &ids);
 564                 if (!id)
 565                         continue;
 566                 id->seen = 1;
 567                 commit->object.flags |= SHOWN;
 568         }
 569
 570         /* Now check the original side for seen ones */
 571         for (p = list; p; p = p->next) {
 572                 struct commit *commit = p->item;
 573                 struct patch_id *ent;
 574
 575                 ent = commit->util;
 576                 if (!ent)
 577                         continue;
 578                 if (ent->seen)
 579                         commit->object.flags |= SHOWN;
 580                 commit->util = NULL;
 581         }
 582
 583         free_patch_ids(&ids);
 584 }
 585
 586 /* How many extra uninteresting commits we want to see.. */
 587 #define SLOP 5
 588
 589 static int still_interesting(struct commit_list *src, unsigned long date, int slop)
 590 {
 591         /*
 592          * No source list at all? We're definitely done..
 593          */
 594         if (!src)
 595                 return 0;
 596
 597         /*
 598          * Does the destination list contain entries with a date
 599          * before the source list? Definitely _not_ done.
 600          */
 601         if (date < src->item->date)
 602                 return SLOP;
 603
 604         /*
 605          * Does the source list still have interesting commits in
 606          * it? Definitely not done..
 607          */
 608         if (!everybody_uninteresting(src))
 609                 return SLOP;
 610
 611         /* Ok, we're closing in.. */
 612         return slop-1;
 613 }
 614
 615 static int limit_list(struct rev_info *revs)
 616 {
 617         int slop = SLOP;
 618         unsigned long date = ~0ul;
 619         struct commit_list *list = revs->commits;
 620         struct commit_list *newlist = NULL;
 621         struct commit_list **p = &newlist;
 622
 623         while (list) {
 624                 struct commit_list *entry = list;
 625                 struct commit *commit = list->item;
 626                 struct object *obj = &commit->object;
 627                 show_early_output_fn_t show;
 628
 629                 list = list->next;
 630                 free(entry);
 631
 632                 if (revs->max_age != -1 && (commit->date < revs->max_age))
 633                         obj->flags |= UNINTERESTING;
 634                 if (add_parents_to_list(revs, commit, &list, NULL) < 0)
 635                         return -1;
 636                 if (obj->flags & UNINTERESTING) {
 637                         mark_parents_uninteresting(commit);
 638                         if (revs->show_all)
 639                                 p = &commit_list_insert(commit, p)->next;
 640                         slop = still_interesting(list, date, slop);
 641                         if (slop)
 642                                 continue;
 643                         /* If showing all, add the whole pending list to the end */
 644                         if (revs->show_all)
 645                                 *p = list;
 646                         break;
 647                 }
 648                 if (revs->min_age != -1 && (commit->date > revs->min_age))
 649                         continue;
 650                 date = commit->date;
 651                 p = &commit_list_insert(commit, p)->next;
 652
 653                 show = show_early_output;
 654                 if (!show)
 655                         continue;
 656
 657                 show(revs, newlist);
 658                 show_early_output = NULL;
 659         }
 660         if (revs->cherry_pick)
 661                 cherry_pick_list(newlist, revs);
 662
 663         revs->commits = newlist;
 664         return 0;
 665 }
 666
 667 struct all_refs_cb {
 668         int all_flags;
 669         int warned_bad_reflog;
 670         struct rev_info *all_revs;
 671         const char *name_for_errormsg;
 672 };
 673
 674 static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 675 {
 676         struct all_refs_cb *cb = cb_data;
 677         struct object *object = get_reference(cb->all_revs, path, sha1,
 678                                               cb->all_flags);
 679         add_pending_object(cb->all_revs, object, path);
 680         return 0;
 681 }
 682
 683 static void handle_refs(struct rev_info *revs, unsigned flags,
 684                 int (*for_each)(each_ref_fn, void *))
 685 {
 686         struct all_refs_cb cb;
 687         cb.all_revs = revs;
 688         cb.all_flags = flags;
 689         for_each(handle_one_ref, &cb);
 690 }
 691
 692 static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
 693 {
 694         struct all_refs_cb *cb = cb_data;
 695         if (!is_null_sha1(sha1)) {
 696                 struct object *o = parse_object(sha1);
 697                 if (o) {
 698                         o->flags |= cb->all_flags;
 699                         add_pending_object(cb->all_revs, o, "");
 700                 }
 701                 else if (!cb->warned_bad_reflog) {
 702                         warning("reflog of '%s' references pruned commits",
 703                                 cb->name_for_errormsg);
 704                         cb->warned_bad_reflog = 1;
 705                 }
 706         }
 707 }
 708
 709 static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 710                 const char *email, unsigned long timestamp, int tz,
 711                 const char *message, void *cb_data)
 712 {
 713         handle_one_reflog_commit(osha1, cb_data);
 714         handle_one_reflog_commit(nsha1, cb_data);
 715         return 0;
 716 }
 717
 718 static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 719 {
 720         struct all_refs_cb *cb = cb_data;
 721         cb->warned_bad_reflog = 0;
 722         cb->name_for_errormsg = path;
 723         for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
 724         return 0;
 725 }
 726
 727 static void handle_reflog(struct rev_info *revs, unsigned flags)
 728 {
 729         struct all_refs_cb cb;
 730         cb.all_revs = revs;
 731         cb.all_flags = flags;
 732         for_each_reflog(handle_one_reflog, &cb);
 733 }
 734
 735 static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
 736 {
 737         unsigned char sha1[20];
 738         struct object *it;
 739         struct commit *commit;
 740         struct commit_list *parents;
 741
 742         if (*arg == '^') {
 743                 flags ^= UNINTERESTING;
 744                 arg++;
 745         }
 746         if (get_sha1(arg, sha1))
 747                 return 0;
 748         while (1) {
 749                 it = get_reference(revs, arg, sha1, 0);
 750                 if (it->type != OBJ_TAG)
 751                         break;
 752                 if (!((struct tag*)it)->tagged)
 753                         return 0;
 754                 hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
 755         }
 756         if (it->type != OBJ_COMMIT)
 757                 return 0;
 758         commit = (struct commit *)it;
 759         for (parents = commit->parents; parents; parents = parents->next) {
 760                 it = &parents->item->object;
 761                 it->flags |= flags;
 762                 add_pending_object(revs, it, arg);
 763         }
 764         return 1;
 765 }
 766
 767 void init_revisions(struct rev_info *revs, const char *prefix)
 768 {
 769         memset(revs, 0, sizeof(*revs));
 770
 771         revs->abbrev = DEFAULT_ABBREV;
 772         revs->ignore_merges = 1;
 773         revs->simplify_history = 1;
 774         DIFF_OPT_SET(&revs->pruning, RECURSIVE);
 775         DIFF_OPT_SET(&revs->pruning, QUIET);
 776         revs->pruning.add_remove = file_add_remove;
 777         revs->pruning.change = file_change;
 778         revs->lifo = 1;
 779         revs->dense = 1;
 780         revs->prefix = prefix;
 781         revs->max_age = -1;
 782         revs->min_age = -1;
 783         revs->skip_count = -1;
 784         revs->max_count = -1;
 785
 786         revs->commit_format = CMIT_FMT_DEFAULT;
 787
 788         diff_setup(&revs->diffopt);
 789         if (prefix && !revs->diffopt.prefix) {
 790                 revs->diffopt.prefix = prefix;
 791                 revs->diffopt.prefix_length = strlen(prefix);
 792         }
 793 }
 794
 795 static void add_pending_commit_list(struct rev_info *revs,
 796                                     struct commit_list *commit_list,
 797                                     unsigned int flags)
 798 {
 799         while (commit_list) {
 800                 struct object *object = &commit_list->item->object;
 801                 object->flags |= flags;
 802                 add_pending_object(revs, object, sha1_to_hex(object->sha1));
 803                 commit_list = commit_list->next;
 804         }
 805 }
 806
 807 static void prepare_show_merge(struct rev_info *revs)
 808 {
 809         struct commit_list *bases;
 810         struct commit *head, *other;
 811         unsigned char sha1[20];
 812         const char **prune = NULL;
 813         int i, prune_num = 1; /* counting terminating NULL */
 814
 815         if (get_sha1("HEAD", sha1) || !(head = lookup_commit(sha1)))
 816                 die("--merge without HEAD?");
 817         if (get_sha1("MERGE_HEAD", sha1) || !(other = lookup_commit(sha1)))
 818                 die("--merge without MERGE_HEAD?");
 819         add_pending_object(revs, &head->object, "HEAD");
 820         add_pending_object(revs, &other->object, "MERGE_HEAD");
 821         bases = get_merge_bases(head, other, 1);
 822         add_pending_commit_list(revs, bases, UNINTERESTING);
 823         free_commit_list(bases);
 824         head->object.flags |= SYMMETRIC_LEFT;
 825
 826         if (!active_nr)
 827                 read_cache();
 828         for (i = 0; i < active_nr; i++) {
 829                 struct cache_entry *ce = active_cache[i];
 830                 if (!ce_stage(ce))
 831                         continue;
 832                 if (ce_path_match(ce, revs->prune_data)) {
 833                         prune_num++;
 834                         prune = xrealloc(prune, sizeof(*prune) * prune_num);
 835                         prune[prune_num-2] = ce->name;
 836                         prune[prune_num-1] = NULL;
 837                 }
 838                 while ((i+1 < active_nr) &&
 839                        ce_same_name(ce, active_cache[i+1]))
 840                         i++;
 841         }
 842         revs->prune_data = prune;
 843         revs->limited = 1;
 844 }
 845
 846 int handle_revision_arg(const char *arg, struct rev_info *revs,
 847                         int flags,
 848                         int cant_be_filename)
 849 {
 850         unsigned mode;
 851         char *dotdot;
 852         struct object *object;
 853         unsigned char sha1[20];
 854         int local_flags;
 855
 856         dotdot = strstr(arg, "..");
 857         if (dotdot) {
 858                 unsigned char from_sha1[20];
 859                 const char *next = dotdot + 2;
 860                 const char *this = arg;
 861                 int symmetric = *next == '.';
 862                 unsigned int flags_exclude = flags ^ UNINTERESTING;
 863
 864                 *dotdot = 0;
 865                 next += symmetric;
 866
 867                 if (!*next)
 868                         next = "HEAD";
 869                 if (dotdot == arg)
 870                         this = "HEAD";
 871                 if (!get_sha1(this, from_sha1) &&
 872                     !get_sha1(next, sha1)) {
 873                         struct commit *a, *b;
 874                         struct commit_list *exclude;
 875
 876                         a = lookup_commit_reference(from_sha1);
 877                         b = lookup_commit_reference(sha1);
 878                         if (!a || !b) {
 879                                 die(symmetric ?
 880                                     "Invalid symmetric difference expression %s...%s" :
 881                                     "Invalid revision range %s..%s",
 882                                     arg, next);
 883                         }
 884
 885                         if (!cant_be_filename) {
 886                                 *dotdot = '.';
 887                                 verify_non_filename(revs->prefix, arg);
 888                         }
 889
 890                         if (symmetric) {
 891                                 exclude = get_merge_bases(a, b, 1);
 892                                 add_pending_commit_list(revs, exclude,
 893                                                         flags_exclude);
 894                                 free_commit_list(exclude);
 895                                 a->object.flags |= flags | SYMMETRIC_LEFT;
 896                         } else
 897                                 a->object.flags |= flags_exclude;
 898                         b->object.flags |= flags;
 899                         add_pending_object(revs, &a->object, this);
 900                         add_pending_object(revs, &b->object, next);
 901                         return 0;
 902                 }
 903                 *dotdot = '.';
 904         }
 905         dotdot = strstr(arg, "^@");
 906         if (dotdot && !dotdot[2]) {
 907                 *dotdot = 0;
 908                 if (add_parents_only(revs, arg, flags))
 909                         return 0;
 910                 *dotdot = '^';
 911         }
 912         dotdot = strstr(arg, "^!");
 913         if (dotdot && !dotdot[2]) {
 914                 *dotdot = 0;
 915                 if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
 916                         *dotdot = '^';
 917         }
 918
 919         local_flags = 0;
 920         if (*arg == '^') {
 921                 local_flags = UNINTERESTING;
 922                 arg++;
 923         }
 924         if (get_sha1_with_mode(arg, sha1, &mode))
 925                 return -1;
 926         if (!cant_be_filename)
 927                 verify_non_filename(revs->prefix, arg);
 928         object = get_reference(revs, arg, sha1, flags ^ local_flags);
 929         add_pending_object_with_mode(revs, object, arg, mode);
 930         return 0;
 931 }
 932
 933 void read_revisions_from_stdin(struct rev_info *revs)
 934 {
 935         char line[1000];
 936
 937         while (fgets(line, sizeof(line), stdin) != NULL) {
 938                 int len = strlen(line);
 939                 if (len && line[len - 1] == '\n')
 940                         line[--len] = '\0';
 941                 if (!len)
 942                         break;
 943                 if (line[0] == '-')
 944                         die("options not supported in --stdin mode");
 945                 if (handle_revision_arg(line, revs, 0, 1))
 946                         die("bad revision '%s'", line);
 947         }
 948 }
 949
 950 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
 951 {
 952         if (!revs->grep_filter) {
 953                 struct grep_opt *opt = xcalloc(1, sizeof(*opt));
 954                 opt->status_only = 1;
 955                 opt->pattern_tail = &(opt->pattern_list);
 956                 opt->regflags = REG_NEWLINE;
 957                 revs->grep_filter = opt;
 958         }
 959         append_grep_pattern(revs->grep_filter, ptn,
 960                             "command line", 0, what);
 961 }
 962
 963 static void add_header_grep(struct rev_info *revs, const char *field, const char *pattern)
 964 {
 965         char *pat;
 966         const char *prefix;
 967         int patlen, fldlen;
 968
 969         fldlen = strlen(field);
 970         patlen = strlen(pattern);
 971         pat = xmalloc(patlen + fldlen + 10);
 972         prefix = ".*";
 973         if (*pattern == '^') {
 974                 prefix = "";
 975                 pattern++;
 976         }
 977         sprintf(pat, "^%s %s%s", field, prefix, pattern);
 978         add_grep(revs, pat, GREP_PATTERN_HEAD);
 979 }
 980
 981 static void add_message_grep(struct rev_info *revs, const char *pattern)
 982 {
 983         add_grep(revs, pattern, GREP_PATTERN_BODY);
 984 }
 985
 986 static void add_ignore_packed(struct rev_info *revs, const char *name)
 987 {
 988         int num = ++revs->num_ignore_packed;
 989
 990         revs->ignore_packed = xrealloc(revs->ignore_packed,
 991                                        sizeof(const char **) * (num + 1));
 992         revs->ignore_packed[num-1] = name;
 993         revs->ignore_packed[num] = NULL;
 994 }
 995
 996 static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
 997                                int *unkc, const char **unkv)
 998 {
 999         const char *arg = argv[0];
1000
1001         /* pseudo revision arguments */
1002         if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
1003             !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
1004             !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
1005             !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk"))
1006         {
1007                 unkv[(*unkc)++] = arg;
1008                 return 1;
1009         }
1010
1011         if (!prefixcmp(arg, "--max-count=")) {
1012                 revs->max_count = atoi(arg + 12);
1013         } else if (!prefixcmp(arg, "--skip=")) {
1014                 revs->skip_count = atoi(arg + 7);
1015         } else if ((*arg == '-') && isdigit(arg[1])) {
1016         /* accept -<digit>, like traditional "head" */
1017                 revs->max_count = atoi(arg + 1);
1018         } else if (!strcmp(arg, "-n")) {
1019                 if (argc <= 1)
1020                         return error("-n requires an argument");
1021                 revs->max_count = atoi(argv[1]);
1022                 return 2;
1023         } else if (!prefixcmp(arg, "-n")) {
1024                 revs->max_count = atoi(arg + 2);
1025         } else if (!prefixcmp(arg, "--max-age=")) {
1026                 revs->max_age = atoi(arg + 10);
1027         } else if (!prefixcmp(arg, "--since=")) {
1028                 revs->max_age = approxidate(arg + 8);
1029         } else if (!prefixcmp(arg, "--after=")) {
1030                 revs->max_age = approxidate(arg + 8);
1031         } else if (!prefixcmp(arg, "--min-age=")) {
1032                 revs->min_age = atoi(arg + 10);
1033         } else if (!prefixcmp(arg, "--before=")) {
1034                 revs->min_age = approxidate(arg + 9);
1035         } else if (!prefixcmp(arg, "--until=")) {
1036                 revs->min_age = approxidate(arg + 8);
1037         } else if (!strcmp(arg, "--first-parent")) {
1038                 revs->first_parent_only = 1;
1039         } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
1040                 init_reflog_walk(&revs->reflog_info);
1041         } else if (!strcmp(arg, "--default")) {
1042                 if (argc <= 1)
1043                         return error("bad --default argument");
1044                 revs->def = argv[1];
1045                 return 2;
1046         } else if (!strcmp(arg, "--merge")) {
1047                 revs->show_merge = 1;
1048         } else if (!strcmp(arg, "--topo-order")) {
1049                 revs->lifo = 1;
1050                 revs->topo_order = 1;
1051         } else if (!strcmp(arg, "--date-order")) {
1052                 revs->lifo = 0;
1053                 revs->topo_order = 1;
1054         } else if (!prefixcmp(arg, "--early-output")) {
1055                 int count = 100;
1056                 switch (arg[14]) {
1057                 case '=':
1058                         count = atoi(arg+15);
1059                         /* Fallthrough */
1060                 case 0:
1061                         revs->topo_order = 1;
1062                        revs->early_output = count;
1063                 }
1064         } else if (!strcmp(arg, "--parents")) {
1065                 revs->rewrite_parents = 1;
1066                 revs->print_parents = 1;
1067         } else if (!strcmp(arg, "--dense")) {
1068                 revs->dense = 1;
1069         } else if (!strcmp(arg, "--sparse")) {
1070                 revs->dense = 0;
1071         } else if (!strcmp(arg, "--show-all")) {
1072                 revs->show_all = 1;
1073         } else if (!strcmp(arg, "--remove-empty")) {
1074                 revs->remove_empty_trees = 1;
1075         } else if (!strcmp(arg, "--no-merges")) {
1076                 revs->no_merges = 1;
1077         } else if (!strcmp(arg, "--boundary")) {
1078                 revs->boundary = 1;
1079         } else if (!strcmp(arg, "--left-right")) {
1080                 revs->left_right = 1;
1081         } else if (!strcmp(arg, "--cherry-pick")) {
1082                 revs->cherry_pick = 1;
1083                 revs->limited = 1;
1084         } else if (!strcmp(arg, "--objects")) {
1085                 revs->tag_objects = 1;
1086                 revs->tree_objects = 1;
1087                 revs->blob_objects = 1;
1088         } else if (!strcmp(arg, "--objects-edge")) {
1089                 revs->tag_objects = 1;
1090                 revs->tree_objects = 1;
1091                 revs->blob_objects = 1;
1092                 revs->edge_hint = 1;
1093         } else if (!strcmp(arg, "--unpacked")) {
1094                 revs->unpacked = 1;
1095                 free(revs->ignore_packed);
1096                 revs->ignore_packed = NULL;
1097                 revs->num_ignore_packed = 0;
1098         } else if (!prefixcmp(arg, "--unpacked=")) {
1099                 revs->unpacked = 1;
1100                 add_ignore_packed(revs, arg+11);
1101         } else if (!strcmp(arg, "-r")) {
1102                 revs->diff = 1;
1103                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1104         } else if (!strcmp(arg, "-t")) {
1105                 revs->diff = 1;
1106                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1107                 DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1108         } else if (!strcmp(arg, "-m")) {
1109                 revs->ignore_merges = 0;
1110         } else if (!strcmp(arg, "-c")) {
1111                 revs->diff = 1;
1112                 revs->dense_combined_merges = 0;
1113                 revs->combine_merges = 1;
1114         } else if (!strcmp(arg, "--cc")) {
1115                 revs->diff = 1;
1116                 revs->dense_combined_merges = 1;
1117                 revs->combine_merges = 1;
1118         } else if (!strcmp(arg, "-v")) {
1119                 revs->verbose_header = 1;
1120         } else if (!strcmp(arg, "--pretty")) {
1121                 revs->verbose_header = 1;
1122                 get_commit_format(arg+8, revs);
1123         } else if (!prefixcmp(arg, "--pretty=")) {
1124                 revs->verbose_header = 1;
1125                 get_commit_format(arg+9, revs);
1126         } else if (!strcmp(arg, "--graph")) {
1127                 revs->topo_order = 1;
1128                 revs->rewrite_parents = 1;
1129                 revs->graph = graph_init(revs);
1130         } else if (!strcmp(arg, "--root")) {
1131                 revs->show_root_diff = 1;
1132         } else if (!strcmp(arg, "--no-commit-id")) {
1133                 revs->no_commit_id = 1;
1134         } else if (!strcmp(arg, "--always")) {
1135                 revs->always_show_header = 1;
1136         } else if (!strcmp(arg, "--no-abbrev")) {
1137                 revs->abbrev = 0;
1138         } else if (!strcmp(arg, "--abbrev")) {
1139                 revs->abbrev = DEFAULT_ABBREV;
1140         } else if (!prefixcmp(arg, "--abbrev=")) {
1141                 revs->abbrev = strtoul(arg + 9, NULL, 10);
1142                 if (revs->abbrev < MINIMUM_ABBREV)
1143                         revs->abbrev = MINIMUM_ABBREV;
1144                 else if (revs->abbrev > 40)
1145                         revs->abbrev = 40;
1146         } else if (!strcmp(arg, "--abbrev-commit")) {
1147                 revs->abbrev_commit = 1;
1148         } else if (!strcmp(arg, "--full-diff")) {
1149                 revs->diff = 1;
1150                 revs->full_diff = 1;
1151         } else if (!strcmp(arg, "--full-history")) {
1152                 revs->simplify_history = 0;
1153         } else if (!strcmp(arg, "--relative-date")) {
1154                 revs->date_mode = DATE_RELATIVE;
1155         } else if (!strncmp(arg, "--date=", 7)) {
1156                 revs->date_mode = parse_date_format(arg + 7);
1157         } else if (!strcmp(arg, "--log-size")) {
1158                 revs->show_log_size = 1;
1159         }
1160         /*
1161          * Grepping the commit log
1162          */
1163         else if (!prefixcmp(arg, "--author=")) {
1164                 add_header_grep(revs, "author", arg+9);
1165         } else if (!prefixcmp(arg, "--committer=")) {
1166                 add_header_grep(revs, "committer", arg+12);
1167         } else if (!prefixcmp(arg, "--grep=")) {
1168                 add_message_grep(revs, arg+7);
1169         } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
1170                 if (revs->grep_filter)
1171                         revs->grep_filter->regflags |= REG_EXTENDED;
1172         } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
1173                 if (revs->grep_filter)
1174                         revs->grep_filter->regflags |= REG_ICASE;
1175         } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
1176                 if (revs->grep_filter)
1177                         revs->grep_filter->fixed = 1;
1178         } else if (!strcmp(arg, "--all-match")) {
1179                 if (revs->grep_filter)
1180                         revs->grep_filter->all_match = 1;
1181         } else if (!prefixcmp(arg, "--encoding=")) {
1182                 arg += 11;
1183                 if (strcmp(arg, "none"))
1184                         git_log_output_encoding = xstrdup(arg);
1185                 else
1186                         git_log_output_encoding = "";
1187         } else if (!strcmp(arg, "--reverse")) {
1188                 revs->reverse ^= 1;
1189         } else if (!strcmp(arg, "--children")) {
1190                 revs->children.name = "children";
1191                 revs->limited = 1;
1192         } else {
1193                 int opts = diff_opt_parse(&revs->diffopt, argv, argc);
1194                 if (!opts)
1195                         unkv[(*unkc)++] = arg;
1196                 return opts;
1197         }
1198
1199         return 1;
1200 }
1201
1202 void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
1203                         const struct option *options,
1204                         const char * const usagestr[])
1205 {
1206         int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
1207                                     &ctx->cpidx, ctx->out);
1208         if (n <= 0) {
1209                 error("unknown option `%s'", ctx->argv[0]);
1210                 usage_with_options(usagestr, options);
1211         }
1212         ctx->argv += n;
1213         ctx->argc -= n;
1214 }
1215
1216 /*
1217  * Parse revision information, filling in the "rev_info" structure,
1218  * and removing the used arguments from the argument list.
1219  *
1220  * Returns the number of arguments left that weren't recognized
1221  * (which are also moved to the head of the argument list)
1222  */
1223 int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
1224 {
1225         int i, flags, left, seen_dashdash;
1226
1227         /* First, search for "--" */
1228         seen_dashdash = 0;
1229         for (i = 1; i < argc; i++) {
1230                 const char *arg = argv[i];
1231                 if (strcmp(arg, "--"))
1232                         continue;
1233                 argv[i] = NULL;
1234                 argc = i;
1235                 if (argv[i + 1])
1236                         revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
1237                 seen_dashdash = 1;
1238                 break;
1239         }
1240
1241         /* Second, deal with arguments and options */
1242         flags = 0;
1243         for (left = i = 1; i < argc; i++) {
1244                 const char *arg = argv[i];
1245                 if (*arg == '-') {
1246                         int opts;
1247
1248                         if (!strcmp(arg, "--all")) {
1249                                 handle_refs(revs, flags, for_each_ref);
1250                                 continue;
1251                         }
1252                         if (!strcmp(arg, "--branches")) {
1253                                 handle_refs(revs, flags, for_each_branch_ref);
1254                                 continue;
1255                         }
1256                         if (!strcmp(arg, "--tags")) {
1257                                 handle_refs(revs, flags, for_each_tag_ref);
1258                                 continue;
1259                         }
1260                         if (!strcmp(arg, "--remotes")) {
1261                                 handle_refs(revs, flags, for_each_remote_ref);
1262                                 continue;
1263                         }
1264                         if (!strcmp(arg, "--reflog")) {
1265                                 handle_reflog(revs, flags);
1266                                 continue;
1267                         }
1268                         if (!strcmp(arg, "--not")) {
1269                                 flags ^= UNINTERESTING;
1270                                 continue;
1271                         }
1272                         if (!strcmp(arg, "--no-walk")) {
1273                                 revs->no_walk = 1;
1274                                 continue;
1275                         }
1276                         if (!strcmp(arg, "--do-walk")) {
1277                                 revs->no_walk = 0;
1278                                 continue;
1279                         }
1280
1281                         opts = handle_revision_opt(revs, argc - i, argv + i, &left, argv);
1282                         if (opts > 0) {
1283                                 i += opts - 1;
1284                                 continue;
1285                         }
1286                         if (opts < 0)
1287                                 exit(128);
1288                         continue;
1289                 }
1290
1291                 if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
1292                         int j;
1293                         if (seen_dashdash || *arg == '^')
1294                                 die("bad revision '%s'", arg);
1295
1296                         /* If we didn't have a "--":
1297                          * (1) all filenames must exist;
1298                          * (2) all rev-args must not be interpretable
1299                          *     as a valid filename.
1300                          * but the latter we have checked in the main loop.
1301                          */
1302                         for (j = i; j < argc; j++)
1303                                 verify_filename(revs->prefix, argv[j]);
1304
1305                         revs->prune_data = get_pathspec(revs->prefix,
1306                                                         argv + i);
1307                         break;
1308                 }
1309         }
1310
1311         if (revs->def == NULL)
1312                 revs->def = def;
1313         if (revs->show_merge)
1314                 prepare_show_merge(revs);
1315         if (revs->def && !revs->pending.nr) {
1316                 unsigned char sha1[20];
1317                 struct object *object;
1318                 unsigned mode;
1319                 if (get_sha1_with_mode(revs->def, sha1, &mode))
1320                         die("bad default revision '%s'", revs->def);
1321                 object = get_reference(revs, revs->def, sha1, 0);
1322                 add_pending_object_with_mode(revs, object, revs->def, mode);
1323         }
1324
1325         /* Did the user ask for any diff output? Run the diff! */
1326         if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
1327                 revs->diff = 1;
1328
1329         /* Pickaxe, diff-filter and rename following need diffs */
1330         if (revs->diffopt.pickaxe ||
1331             revs->diffopt.filter ||
1332             DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1333                 revs->diff = 1;
1334
1335         if (revs->topo_order)
1336                 revs->limited = 1;
1337
1338         if (revs->prune_data) {
1339                 diff_tree_setup_paths(revs->prune_data, &revs->pruning);
1340                 /* Can't prune commits with rename following: the paths change.. */
1341                 if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1342                         revs->prune = 1;
1343                 if (!revs->full_diff)
1344                         diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
1345         }
1346         if (revs->combine_merges) {
1347                 revs->ignore_merges = 0;
1348                 if (revs->dense_combined_merges && !revs->diffopt.output_format)
1349                         revs->diffopt.output_format = DIFF_FORMAT_PATCH;
1350         }
1351         revs->diffopt.abbrev = revs->abbrev;
1352         if (diff_setup_done(&revs->diffopt) < 0)
1353                 die("diff_setup_done failed");
1354
1355         if (revs->grep_filter) {
1356                 compile_grep_patterns(revs->grep_filter);
1357         }
1358
1359         if (revs->reverse && revs->reflog_info)
1360                 die("cannot combine --reverse with --walk-reflogs");
1361         if (revs->rewrite_parents && revs->children.name)
1362                 die("cannot combine --parents and --children");
1363
1364         /*
1365          * Limitations on the graph functionality
1366          */
1367         if (revs->reverse && revs->graph)
1368                 die("cannot combine --reverse with --graph");
1369
1370         if (revs->reflog_info && revs->graph)
1371                 die("cannot combine --walk-reflogs with --graph");
1372
1373         return left;
1374 }
1375
1376 static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
1377 {
1378         struct commit_list *l = xcalloc(1, sizeof(*l));
1379
1380         l->item = child;
1381         l->next = add_decoration(&revs->children, &parent->object, l);
1382 }
1383
1384 static void set_children(struct rev_info *revs)
1385 {
1386         struct commit_list *l;
1387         for (l = revs->commits; l; l = l->next) {
1388                 struct commit *commit = l->item;
1389                 struct commit_list *p;
1390
1391                 for (p = commit->parents; p; p = p->next)
1392                         add_child(revs, p->item, commit);
1393         }
1394 }
1395
1396 int prepare_revision_walk(struct rev_info *revs)
1397 {
1398         int nr = revs->pending.nr;
1399         struct object_array_entry *e, *list;
1400
1401         e = list = revs->pending.objects;
1402         revs->pending.nr = 0;
1403         revs->pending.alloc = 0;
1404         revs->pending.objects = NULL;
1405         while (--nr >= 0) {
1406                 struct commit *commit = handle_commit(revs, e->item, e->name);
1407                 if (commit) {
1408                         if (!(commit->object.flags & SEEN)) {
1409                                 commit->object.flags |= SEEN;
1410                                 insert_by_date(commit, &revs->commits);
1411                         }
1412                 }
1413                 e++;
1414         }
1415         free(list);
1416
1417         if (revs->no_walk)
1418                 return 0;
1419         if (revs->limited)
1420                 if (limit_list(revs) < 0)
1421                         return -1;
1422         if (revs->topo_order)
1423                 sort_in_topological_order(&revs->commits, revs->lifo);
1424         if (revs->children.name)
1425                 set_children(revs);
1426         return 0;
1427 }
1428
1429 enum rewrite_result {
1430         rewrite_one_ok,
1431         rewrite_one_noparents,
1432         rewrite_one_error,
1433 };
1434
1435 static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
1436 {
1437         struct commit_list *cache = NULL;
1438
1439         for (;;) {
1440                 struct commit *p = *pp;
1441                 if (!revs->limited)
1442                         if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0)
1443                                 return rewrite_one_error;
1444                 if (p->parents && p->parents->next)
1445                         return rewrite_one_ok;
1446                 if (p->object.flags & UNINTERESTING)
1447                         return rewrite_one_ok;
1448                 if (!(p->object.flags & TREESAME))
1449                         return rewrite_one_ok;
1450                 if (!p->parents)
1451                         return rewrite_one_noparents;
1452                 *pp = p->parents->item;
1453         }
1454 }
1455
1456 static void remove_duplicate_parents(struct commit *commit)
1457 {
1458         struct commit_list **pp, *p;
1459
1460         /* Examine existing parents while marking ones we have seen... */
1461         pp = &commit->parents;
1462         while ((p = *pp) != NULL) {
1463                 struct commit *parent = p->item;
1464                 if (parent->object.flags & TMP_MARK) {
1465                         *pp = p->next;
1466                         continue;
1467                 }
1468                 parent->object.flags |= TMP_MARK;
1469                 pp = &p->next;
1470         }
1471         /* ... and clear the temporary mark */
1472         for (p = commit->parents; p; p = p->next)
1473                 p->item->object.flags &= ~TMP_MARK;
1474 }
1475
1476 static int rewrite_parents(struct rev_info *revs, struct commit *commit)
1477 {
1478         struct commit_list **pp = &commit->parents;
1479         while (*pp) {
1480                 struct commit_list *parent = *pp;
1481                 switch (rewrite_one(revs, &parent->item)) {
1482                 case rewrite_one_ok:
1483                         break;
1484                 case rewrite_one_noparents:
1485                         *pp = parent->next;
1486                         continue;
1487                 case rewrite_one_error:
1488                         return -1;
1489                 }
1490                 pp = &parent->next;
1491         }
1492         remove_duplicate_parents(commit);
1493         return 0;
1494 }
1495
1496 static int commit_match(struct commit *commit, struct rev_info *opt)
1497 {
1498         if (!opt->grep_filter)
1499                 return 1;
1500         return grep_buffer(opt->grep_filter,
1501                            NULL, /* we say nothing, not even filename */
1502                            commit->buffer, strlen(commit->buffer));
1503 }
1504
1505 static inline int want_ancestry(struct rev_info *revs)
1506 {
1507         return (revs->rewrite_parents || revs->children.name);
1508 }
1509
1510 enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
1511 {
1512         if (commit->object.flags & SHOWN)
1513                 return commit_ignore;
1514         if (revs->unpacked && has_sha1_pack(commit->object.sha1, revs->ignore_packed))
1515                 return commit_ignore;
1516         if (revs->show_all)
1517                 return commit_show;
1518         if (commit->object.flags & UNINTERESTING)
1519                 return commit_ignore;
1520         if (revs->min_age != -1 && (commit->date > revs->min_age))
1521                 return commit_ignore;
1522         if (revs->no_merges && commit->parents && commit->parents->next)
1523                 return commit_ignore;
1524         if (!commit_match(commit, revs))
1525                 return commit_ignore;
1526         if (revs->prune && revs->dense) {
1527                 /* Commit without changes? */
1528                 if (commit->object.flags & TREESAME) {
1529                         /* drop merges unless we want parenthood */
1530                         if (!want_ancestry(revs))
1531                                 return commit_ignore;
1532                         /* non-merge - always ignore it */
1533                         if (!commit->parents || !commit->parents->next)
1534                                 return commit_ignore;
1535                 }
1536                 if (want_ancestry(revs) && rewrite_parents(revs, commit) < 0)
1537                         return commit_error;
1538         }
1539         return commit_show;
1540 }
1541
1542 static struct commit *get_revision_1(struct rev_info *revs)
1543 {
1544         if (!revs->commits)
1545                 return NULL;
1546
1547         do {
1548                 struct commit_list *entry = revs->commits;
1549                 struct commit *commit = entry->item;
1550
1551                 revs->commits = entry->next;
1552                 free(entry);
1553
1554                 if (revs->reflog_info)
1555                         fake_reflog_parent(revs->reflog_info, commit);
1556
1557                 /*
1558                  * If we haven't done the list limiting, we need to look at
1559                  * the parents here. We also need to do the date-based limiting
1560                  * that we'd otherwise have done in limit_list().
1561                  */
1562                 if (!revs->limited) {
1563                         if (revs->max_age != -1 &&
1564                             (commit->date < revs->max_age))
1565                                 continue;
1566                         if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0)
1567                                 return NULL;
1568                 }
1569
1570                 switch (simplify_commit(revs, commit)) {
1571                 case commit_ignore:
1572                         continue;
1573                 case commit_error:
1574                         return NULL;
1575                 default:
1576                         return commit;
1577                 }
1578         } while (revs->commits);
1579         return NULL;
1580 }
1581
1582 static void gc_boundary(struct object_array *array)
1583 {
1584         unsigned nr = array->nr;
1585         unsigned alloc = array->alloc;
1586         struct object_array_entry *objects = array->objects;
1587
1588         if (alloc <= nr) {
1589                 unsigned i, j;
1590                 for (i = j = 0; i < nr; i++) {
1591                         if (objects[i].item->flags & SHOWN)
1592                                 continue;
1593                         if (i != j)
1594                                 objects[j] = objects[i];
1595                         j++;
1596                 }
1597                 for (i = j; i < nr; i++)
1598                         objects[i].item = NULL;
1599                 array->nr = j;
1600         }
1601 }
1602
1603 static void create_boundary_commit_list(struct rev_info *revs)
1604 {
1605         unsigned i;
1606         struct commit *c;
1607         struct object_array *array = &revs->boundary_commits;
1608         struct object_array_entry *objects = array->objects;
1609
1610         /*
1611          * If revs->commits is non-NULL at this point, an error occurred in
1612          * get_revision_1().  Ignore the error and continue printing the
1613          * boundary commits anyway.  (This is what the code has always
1614          * done.)
1615          */
1616         if (revs->commits) {
1617                 free_commit_list(revs->commits);
1618                 revs->commits = NULL;
1619         }
1620
1621         /*
1622          * Put all of the actual boundary commits from revs->boundary_commits
1623          * into revs->commits
1624          */
1625         for (i = 0; i < array->nr; i++) {
1626                 c = (struct commit *)(objects[i].item);
1627                 if (!c)
1628                         continue;
1629                 if (!(c->object.flags & CHILD_SHOWN))
1630                         continue;
1631                 if (c->object.flags & (SHOWN | BOUNDARY))
1632                         continue;
1633                 c->object.flags |= BOUNDARY;
1634                 commit_list_insert(c, &revs->commits);
1635         }
1636
1637         /*
1638          * If revs->topo_order is set, sort the boundary commits
1639          * in topological order
1640          */
1641         sort_in_topological_order(&revs->commits, revs->lifo);
1642 }
1643
1644 static struct commit *get_revision_internal(struct rev_info *revs)
1645 {
1646         struct commit *c = NULL;
1647         struct commit_list *l;
1648
1649         if (revs->boundary == 2) {
1650                 /*
1651                  * All of the normal commits have already been returned,
1652                  * and we are now returning boundary commits.
1653                  * create_boundary_commit_list() has populated
1654                  * revs->commits with the remaining commits to return.
1655                  */
1656                 c = pop_commit(&revs->commits);
1657                 if (c)
1658                         c->object.flags |= SHOWN;
1659                 return c;
1660         }
1661
1662         if (revs->reverse) {
1663                 int limit = -1;
1664
1665                 if (0 <= revs->max_count) {
1666                         limit = revs->max_count;
1667                         if (0 < revs->skip_count)
1668                                 limit += revs->skip_count;
1669                 }
1670                 l = NULL;
1671                 while ((c = get_revision_1(revs))) {
1672                         commit_list_insert(c, &l);
1673                         if ((0 < limit) && !--limit)
1674                                 break;
1675                 }
1676                 revs->commits = l;
1677                 revs->reverse = 0;
1678                 revs->max_count = -1;
1679                 c = NULL;
1680         }
1681
1682         /*
1683          * Now pick up what they want to give us
1684          */
1685         c = get_revision_1(revs);
1686         if (c) {
1687                 while (0 < revs->skip_count) {
1688                         revs->skip_count--;
1689                         c = get_revision_1(revs);
1690                         if (!c)
1691                                 break;
1692                 }
1693         }
1694
1695         /*
1696          * Check the max_count.
1697          */
1698         switch (revs->max_count) {
1699         case -1:
1700                 break;
1701         case 0:
1702                 c = NULL;
1703                 break;
1704         default:
1705                 revs->max_count--;
1706         }
1707
1708         if (c)
1709                 c->object.flags |= SHOWN;
1710
1711         if (!revs->boundary) {
1712                 return c;
1713         }
1714
1715         if (!c) {
1716                 /*
1717                  * get_revision_1() runs out the commits, and
1718                  * we are done computing the boundaries.
1719                  * switch to boundary commits output mode.
1720                  */
1721                 revs->boundary = 2;
1722
1723                 /*
1724                  * Update revs->commits to contain the list of
1725                  * boundary commits.
1726                  */
1727                 create_boundary_commit_list(revs);
1728
1729                 return get_revision_internal(revs);
1730         }
1731
1732         /*
1733          * boundary commits are the commits that are parents of the
1734          * ones we got from get_revision_1() but they themselves are
1735          * not returned from get_revision_1().  Before returning
1736          * 'c', we need to mark its parents that they could be boundaries.
1737          */
1738
1739         for (l = c->parents; l; l = l->next) {
1740                 struct object *p;
1741                 p = &(l->item->object);
1742                 if (p->flags & (CHILD_SHOWN | SHOWN))
1743                         continue;
1744                 p->flags |= CHILD_SHOWN;
1745                 gc_boundary(&revs->boundary_commits);
1746                 add_object_array(p, NULL, &revs->boundary_commits);
1747         }
1748
1749         return c;
1750 }
1751
1752 struct commit *get_revision(struct rev_info *revs)
1753 {
1754         struct commit *c = get_revision_internal(revs);
1755         if (c && revs->graph)
1756                 graph_update(revs->graph, c);
1757         return c;
1758 }