revision.c

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