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 #include "log-tree.h"
  15 #include "string-list.h"
  16
  17 volatile show_early_output_fn_t show_early_output;
  18
  19 char *path_name(const struct name_path *path, const char *name)
  20 {
  21         const struct name_path *p;
  22         char *n, *m;
  23         int nlen = strlen(name);
  24         int len = nlen + 1;
  25
  26         for (p = path; p; p = p->up) {
  27                 if (p->elem_len)
  28                         len += p->elem_len + 1;
  29         }
  30         n = xmalloc(len);
  31         m = n + len - (nlen + 1);
  32         strcpy(m, name);
  33         for (p = path; p; p = p->up) {
  34                 if (p->elem_len) {
  35                         m -= p->elem_len + 1;
  36                         memcpy(m, p->elem, p->elem_len);
  37                         m[p->elem_len] = '/';
  38                 }
  39         }
  40         return n;
  41 }
  42
  43 static int show_path_component_truncated(FILE *out, const char *name, int len)
  44 {
  45         int cnt;
  46         for (cnt = 0; cnt < len; cnt++) {
  47                 int ch = name[cnt];
  48                 if (!ch || ch == '\n')
  49                         return -1;
  50                 fputc(ch, out);
  51         }
  52         return len;
  53 }
  54
  55 static int show_path_truncated(FILE *out, const struct name_path *path)
  56 {
  57         int emitted, ours;
  58
  59         if (!path)
  60                 return 0;
  61         emitted = show_path_truncated(out, path->up);
  62         if (emitted < 0)
  63                 return emitted;
  64         if (emitted)
  65                 fputc('/', out);
  66         ours = show_path_component_truncated(out, path->elem, path->elem_len);
  67         if (ours < 0)
  68                 return ours;
  69         return ours || emitted;
  70 }
  71
  72 void show_object_with_name(FILE *out, struct object *obj, const struct name_path *path, const char *component)
  73 {
  74         struct name_path leaf;
  75         leaf.up = (struct name_path *)path;
  76         leaf.elem = component;
  77         leaf.elem_len = strlen(component);
  78
  79         fprintf(out, "%s ", sha1_to_hex(obj->sha1));
  80         show_path_truncated(out, &leaf);
  81         fputc('\n', out);
  82 }
  83
  84 void add_object(struct object *obj,
  85                 struct object_array *p,
  86                 struct name_path *path,
  87                 const char *name)
  88 {
  89         add_object_array(obj, path_name(path, name), p);
  90 }
  91
  92 static void mark_blob_uninteresting(struct blob *blob)
  93 {
  94         if (!blob)
  95                 return;
  96         if (blob->object.flags & UNINTERESTING)
  97                 return;
  98         blob->object.flags |= UNINTERESTING;
  99 }
 100
 101 void mark_tree_uninteresting(struct tree *tree)
 102 {
 103         struct tree_desc desc;
 104         struct name_entry entry;
 105         struct object *obj = &tree->object;
 106
 107         if (!tree)
 108                 return;
 109         if (obj->flags & UNINTERESTING)
 110                 return;
 111         obj->flags |= UNINTERESTING;
 112         if (!has_sha1_file(obj->sha1))
 113                 return;
 114         if (parse_tree(tree) < 0)
 115                 die("bad tree %s", sha1_to_hex(obj->sha1));
 116
 117         init_tree_desc(&desc, tree->buffer, tree->size);
 118         while (tree_entry(&desc, &entry)) {
 119                 switch (object_type(entry.mode)) {
 120                 case OBJ_TREE:
 121                         mark_tree_uninteresting(lookup_tree(entry.sha1));
 122                         break;
 123                 case OBJ_BLOB:
 124                         mark_blob_uninteresting(lookup_blob(entry.sha1));
 125                         break;
 126                 default:
 127                         /* Subproject commit - not in this repository */
 128                         break;
 129                 }
 130         }
 131
 132         /*
 133          * We don't care about the tree any more
 134          * after it has been marked uninteresting.
 135          */
 136         free(tree->buffer);
 137         tree->buffer = NULL;
 138 }
 139
 140 void mark_parents_uninteresting(struct commit *commit)
 141 {
 142         struct commit_list *parents = commit->parents;
 143
 144         while (parents) {
 145                 struct commit *commit = parents->item;
 146                 if (!(commit->object.flags & UNINTERESTING)) {
 147                         commit->object.flags |= UNINTERESTING;
 148
 149                         /*
 150                          * Normally we haven't parsed the parent
 151                          * yet, so we won't have a parent of a parent
 152                          * here. However, it may turn out that we've
 153                          * reached this commit some other way (where it
 154                          * wasn't uninteresting), in which case we need
 155                          * to mark its parents recursively too..
 156                          */
 157                         if (commit->parents)
 158                                 mark_parents_uninteresting(commit);
 159                 }
 160
 161                 /*
 162                  * A missing commit is ok iff its parent is marked
 163                  * uninteresting.
 164                  *
 165                  * We just mark such a thing parsed, so that when
 166                  * it is popped next time around, we won't be trying
 167                  * to parse it and get an error.
 168                  */
 169                 if (!has_sha1_file(commit->object.sha1))
 170                         commit->object.parsed = 1;
 171                 parents = parents->next;
 172         }
 173 }
 174
 175 static void add_pending_object_with_mode(struct rev_info *revs, struct object *obj, const char *name, unsigned mode)
 176 {
 177         if (!obj)
 178                 return;
 179         if (revs->no_walk && (obj->flags & UNINTERESTING))
 180                 revs->no_walk = 0;
 181         if (revs->reflog_info && obj->type == OBJ_COMMIT) {
 182                 struct strbuf buf = STRBUF_INIT;
 183                 int len = interpret_branch_name(name, &buf);
 184                 int st;
 185
 186                 if (0 < len && name[len] && buf.len)
 187                         strbuf_addstr(&buf, name + len);
 188                 st = add_reflog_for_walk(revs->reflog_info,
 189                                          (struct commit *)obj,
 190                                          buf.buf[0] ? buf.buf: name);
 191                 strbuf_release(&buf);
 192                 if (st)
 193                         return;
 194         }
 195         add_object_array_with_mode(obj, name, &revs->pending, mode);
 196 }
 197
 198 void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
 199 {
 200         add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
 201 }
 202
 203 void add_head_to_pending(struct rev_info *revs)
 204 {
 205         unsigned char sha1[20];
 206         struct object *obj;
 207         if (get_sha1("HEAD", sha1))
 208                 return;
 209         obj = parse_object(sha1);
 210         if (!obj)
 211                 return;
 212         add_pending_object(revs, obj, "HEAD");
 213 }
 214
 215 static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
 216 {
 217         struct object *object;
 218
 219         object = parse_object(sha1);
 220         if (!object) {
 221                 if (revs->ignore_missing)
 222                         return object;
 223                 die("bad object %s", name);
 224         }
 225         object->flags |= flags;
 226         return object;
 227 }
 228
 229 void add_pending_sha1(struct rev_info *revs, const char *name,
 230                       const unsigned char *sha1, unsigned int flags)
 231 {
 232         struct object *object = get_reference(revs, name, sha1, flags);
 233         add_pending_object(revs, object, name);
 234 }
 235
 236 static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
 237 {
 238         unsigned long flags = object->flags;
 239
 240         /*
 241          * Tag object? Look what it points to..
 242          */
 243         while (object->type == OBJ_TAG) {
 244                 struct tag *tag = (struct tag *) object;
 245                 if (revs->tag_objects && !(flags & UNINTERESTING))
 246                         add_pending_object(revs, object, tag->tag);
 247                 if (!tag->tagged)
 248                         die("bad tag");
 249                 object = parse_object(tag->tagged->sha1);
 250                 if (!object) {
 251                         if (flags & UNINTERESTING)
 252                                 return NULL;
 253                         die("bad object %s", sha1_to_hex(tag->tagged->sha1));
 254                 }
 255         }
 256
 257         /*
 258          * Commit object? Just return it, we'll do all the complex
 259          * reachability crud.
 260          */
 261         if (object->type == OBJ_COMMIT) {
 262                 struct commit *commit = (struct commit *)object;
 263                 if (parse_commit(commit) < 0)
 264                         die("unable to parse commit %s", name);
 265                 if (flags & UNINTERESTING) {
 266                         commit->object.flags |= UNINTERESTING;
 267                         mark_parents_uninteresting(commit);
 268                         revs->limited = 1;
 269                 }
 270                 if (revs->show_source && !commit->util)
 271                         commit->util = (void *) name;
 272                 return commit;
 273         }
 274
 275         /*
 276          * Tree object? Either mark it uninteresting, or add it
 277          * to the list of objects to look at later..
 278          */
 279         if (object->type == OBJ_TREE) {
 280                 struct tree *tree = (struct tree *)object;
 281                 if (!revs->tree_objects)
 282                         return NULL;
 283                 if (flags & UNINTERESTING) {
 284                         mark_tree_uninteresting(tree);
 285                         return NULL;
 286                 }
 287                 add_pending_object(revs, object, "");
 288                 return NULL;
 289         }
 290
 291         /*
 292          * Blob object? You know the drill by now..
 293          */
 294         if (object->type == OBJ_BLOB) {
 295                 struct blob *blob = (struct blob *)object;
 296                 if (!revs->blob_objects)
 297                         return NULL;
 298                 if (flags & UNINTERESTING) {
 299                         mark_blob_uninteresting(blob);
 300                         return NULL;
 301                 }
 302                 add_pending_object(revs, object, "");
 303                 return NULL;
 304         }
 305         die("%s is unknown object", name);
 306 }
 307
 308 static int everybody_uninteresting(struct commit_list *orig)
 309 {
 310         struct commit_list *list = orig;
 311         while (list) {
 312                 struct commit *commit = list->item;
 313                 list = list->next;
 314                 if (commit->object.flags & UNINTERESTING)
 315                         continue;
 316                 return 0;
 317         }
 318         return 1;
 319 }
 320
 321 /*
 322  * The goal is to get REV_TREE_NEW as the result only if the
 323  * diff consists of all '+' (and no other changes), REV_TREE_OLD
 324  * if the whole diff is removal of old data, and otherwise
 325  * REV_TREE_DIFFERENT (of course if the trees are the same we
 326  * want REV_TREE_SAME).
 327  * That means that once we get to REV_TREE_DIFFERENT, we do not
 328  * have to look any further.
 329  */
 330 static int tree_difference = REV_TREE_SAME;
 331
 332 static void file_add_remove(struct diff_options *options,
 333                     int addremove, unsigned mode,
 334                     const unsigned char *sha1,
 335                     int sha1_valid,
 336                     const char *fullpath, unsigned dirty_submodule)
 337 {
 338         int diff = addremove == '+' ? REV_TREE_NEW : REV_TREE_OLD;
 339
 340         tree_difference |= diff;
 341         if (tree_difference == REV_TREE_DIFFERENT)
 342                 DIFF_OPT_SET(options, HAS_CHANGES);
 343 }
 344
 345 static void file_change(struct diff_options *options,
 346                  unsigned old_mode, unsigned new_mode,
 347                  const unsigned char *old_sha1,
 348                  const unsigned char *new_sha1,
 349                  int old_sha1_valid, int new_sha1_valid,
 350                  const char *fullpath,
 351                  unsigned old_dirty_submodule, unsigned new_dirty_submodule)
 352 {
 353         tree_difference = REV_TREE_DIFFERENT;
 354         DIFF_OPT_SET(options, HAS_CHANGES);
 355 }
 356
 357 static int rev_compare_tree(struct rev_info *revs, struct commit *parent, struct commit *commit)
 358 {
 359         struct tree *t1 = parent->tree;
 360         struct tree *t2 = commit->tree;
 361
 362         if (!t1)
 363                 return REV_TREE_NEW;
 364         if (!t2)
 365                 return REV_TREE_OLD;
 366
 367         if (revs->simplify_by_decoration) {
 368                 /*
 369                  * If we are simplifying by decoration, then the commit
 370                  * is worth showing if it has a tag pointing at it.
 371                  */
 372                 if (lookup_decoration(&name_decoration, &commit->object))
 373                         return REV_TREE_DIFFERENT;
 374                 /*
 375                  * A commit that is not pointed by a tag is uninteresting
 376                  * if we are not limited by path.  This means that you will
 377                  * see the usual "commits that touch the paths" plus any
 378                  * tagged commit by specifying both --simplify-by-decoration
 379                  * and pathspec.
 380                  */
 381                 if (!revs->prune_data.nr)
 382                         return REV_TREE_SAME;
 383         }
 384
 385         tree_difference = REV_TREE_SAME;
 386         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 387         if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
 388                            &revs->pruning) < 0)
 389                 return REV_TREE_DIFFERENT;
 390         return tree_difference;
 391 }
 392
 393 static int rev_same_tree_as_empty(struct rev_info *revs, struct commit *commit)
 394 {
 395         int retval;
 396         void *tree;
 397         unsigned long size;
 398         struct tree_desc empty, real;
 399         struct tree *t1 = commit->tree;
 400
 401         if (!t1)
 402                 return 0;
 403
 404         tree = read_object_with_reference(t1->object.sha1, tree_type, &size, NULL);
 405         if (!tree)
 406                 return 0;
 407         init_tree_desc(&real, tree, size);
 408         init_tree_desc(&empty, "", 0);
 409
 410         tree_difference = REV_TREE_SAME;
 411         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 412         retval = diff_tree(&empty, &real, "", &revs->pruning);
 413         free(tree);
 414
 415         return retval >= 0 && (tree_difference == REV_TREE_SAME);
 416 }
 417
 418 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 419 {
 420         struct commit_list **pp, *parent;
 421         int tree_changed = 0, tree_same = 0, nth_parent = 0;
 422
 423         /*
 424          * If we don't do pruning, everything is interesting
 425          */
 426         if (!revs->prune)
 427                 return;
 428
 429         if (!commit->tree)
 430                 return;
 431
 432         if (!commit->parents) {
 433                 if (rev_same_tree_as_empty(revs, commit))
 434                         commit->object.flags |= TREESAME;
 435                 return;
 436         }
 437
 438         /*
 439          * Normal non-merge commit? If we don't want to make the
 440          * history dense, we consider it always to be a change..
 441          */
 442         if (!revs->dense && !commit->parents->next)
 443                 return;
 444
 445         pp = &commit->parents;
 446         while ((parent = *pp) != NULL) {
 447                 struct commit *p = parent->item;
 448
 449                 /*
 450                  * Do not compare with later parents when we care only about
 451                  * the first parent chain, in order to avoid derailing the
 452                  * traversal to follow a side branch that brought everything
 453                  * in the path we are limited to by the pathspec.
 454                  */
 455                 if (revs->first_parent_only && nth_parent++)
 456                         break;
 457                 if (parse_commit(p) < 0)
 458                         die("cannot simplify commit %s (because of %s)",
 459                             sha1_to_hex(commit->object.sha1),
 460                             sha1_to_hex(p->object.sha1));
 461                 switch (rev_compare_tree(revs, p, commit)) {
 462                 case REV_TREE_SAME:
 463                         tree_same = 1;
 464                         if (!revs->simplify_history || (p->object.flags & UNINTERESTING)) {
 465                                 /* Even if a merge with an uninteresting
 466                                  * side branch brought the entire change
 467                                  * we are interested in, we do not want
 468                                  * to lose the other branches of this
 469                                  * merge, so we just keep going.
 470                                  */
 471                                 pp = &parent->next;
 472                                 continue;
 473                         }
 474                         parent->next = NULL;
 475                         commit->parents = parent;
 476                         commit->object.flags |= TREESAME;
 477                         return;
 478
 479                 case REV_TREE_NEW:
 480                         if (revs->remove_empty_trees &&
 481                             rev_same_tree_as_empty(revs, p)) {
 482                                 /* We are adding all the specified
 483                                  * paths from this parent, so the
 484                                  * history beyond this parent is not
 485                                  * interesting.  Remove its parents
 486                                  * (they are grandparents for us).
 487                                  * IOW, we pretend this parent is a
 488                                  * "root" commit.
 489                                  */
 490                                 if (parse_commit(p) < 0)
 491                                         die("cannot simplify commit %s (invalid %s)",
 492                                             sha1_to_hex(commit->object.sha1),
 493                                             sha1_to_hex(p->object.sha1));
 494                                 p->parents = NULL;
 495                         }
 496                 /* fallthrough */
 497                 case REV_TREE_OLD:
 498                 case REV_TREE_DIFFERENT:
 499                         tree_changed = 1;
 500                         pp = &parent->next;
 501                         continue;
 502                 }
 503                 die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
 504         }
 505         if (tree_changed && !tree_same)
 506                 return;
 507         commit->object.flags |= TREESAME;
 508 }
 509
 510 static void commit_list_insert_by_date_cached(struct commit *p, struct commit_list **head,
 511                     struct commit_list *cached_base, struct commit_list **cache)
 512 {
 513         struct commit_list *new_entry;
 514
 515         if (cached_base && p->date < cached_base->item->date)
 516                 new_entry = commit_list_insert_by_date(p, &cached_base->next);
 517         else
 518                 new_entry = commit_list_insert_by_date(p, head);
 519
 520         if (cache && (!*cache || p->date < (*cache)->item->date))
 521                 *cache = new_entry;
 522 }
 523
 524 static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
 525                     struct commit_list **list, struct commit_list **cache_ptr)
 526 {
 527         struct commit_list *parent = commit->parents;
 528         unsigned left_flag;
 529         struct commit_list *cached_base = cache_ptr ? *cache_ptr : NULL;
 530
 531         if (commit->object.flags & ADDED)
 532                 return 0;
 533         commit->object.flags |= ADDED;
 534
 535         /*
 536          * If the commit is uninteresting, don't try to
 537          * prune parents - we want the maximal uninteresting
 538          * set.
 539          *
 540          * Normally we haven't parsed the parent
 541          * yet, so we won't have a parent of a parent
 542          * here. However, it may turn out that we've
 543          * reached this commit some other way (where it
 544          * wasn't uninteresting), in which case we need
 545          * to mark its parents recursively too..
 546          */
 547         if (commit->object.flags & UNINTERESTING) {
 548                 while (parent) {
 549                         struct commit *p = parent->item;
 550                         parent = parent->next;
 551                         if (p)
 552                                 p->object.flags |= UNINTERESTING;
 553                         if (parse_commit(p) < 0)
 554                                 continue;
 555                         if (p->parents)
 556                                 mark_parents_uninteresting(p);
 557                         if (p->object.flags & SEEN)
 558                                 continue;
 559                         p->object.flags |= SEEN;
 560                         commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
 561                 }
 562                 return 0;
 563         }
 564
 565         /*
 566          * Ok, the commit wasn't uninteresting. Try to
 567          * simplify the commit history and find the parent
 568          * that has no differences in the path set if one exists.
 569          */
 570         try_to_simplify_commit(revs, commit);
 571
 572         if (revs->no_walk)
 573                 return 0;
 574
 575         left_flag = (commit->object.flags & SYMMETRIC_LEFT);
 576
 577         for (parent = commit->parents; parent; parent = parent->next) {
 578                 struct commit *p = parent->item;
 579
 580                 if (parse_commit(p) < 0)
 581                         return -1;
 582                 if (revs->show_source && !p->util)
 583                         p->util = commit->util;
 584                 p->object.flags |= left_flag;
 585                 if (!(p->object.flags & SEEN)) {
 586                         p->object.flags |= SEEN;
 587                         commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
 588                 }
 589                 if (revs->first_parent_only)
 590                         break;
 591         }
 592         return 0;
 593 }
 594
 595 static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
 596 {
 597         struct commit_list *p;
 598         int left_count = 0, right_count = 0;
 599         int left_first;
 600         struct patch_ids ids;
 601         unsigned cherry_flag;
 602
 603         /* First count the commits on the left and on the right */
 604         for (p = list; p; p = p->next) {
 605                 struct commit *commit = p->item;
 606                 unsigned flags = commit->object.flags;
 607                 if (flags & BOUNDARY)
 608                         ;
 609                 else if (flags & SYMMETRIC_LEFT)
 610                         left_count++;
 611                 else
 612                         right_count++;
 613         }
 614
 615         if (!left_count || !right_count)
 616                 return;
 617
 618         left_first = left_count < right_count;
 619         init_patch_ids(&ids);
 620         ids.diffopts.pathspec = revs->diffopt.pathspec;
 621
 622         /* Compute patch-ids for one side */
 623         for (p = list; p; p = p->next) {
 624                 struct commit *commit = p->item;
 625                 unsigned flags = commit->object.flags;
 626
 627                 if (flags & BOUNDARY)
 628                         continue;
 629                 /*
 630                  * If we have fewer left, left_first is set and we omit
 631                  * commits on the right branch in this loop.  If we have
 632                  * fewer right, we skip the left ones.
 633                  */
 634                 if (left_first != !!(flags & SYMMETRIC_LEFT))
 635                         continue;
 636                 commit->util = add_commit_patch_id(commit, &ids);
 637         }
 638
 639         /* either cherry_mark or cherry_pick are true */
 640         cherry_flag = revs->cherry_mark ? PATCHSAME : SHOWN;
 641
 642         /* Check the other side */
 643         for (p = list; p; p = p->next) {
 644                 struct commit *commit = p->item;
 645                 struct patch_id *id;
 646                 unsigned flags = commit->object.flags;
 647
 648                 if (flags & BOUNDARY)
 649                         continue;
 650                 /*
 651                  * If we have fewer left, left_first is set and we omit
 652                  * commits on the left branch in this loop.
 653                  */
 654                 if (left_first == !!(flags & SYMMETRIC_LEFT))
 655                         continue;
 656
 657                 /*
 658                  * Have we seen the same patch id?
 659                  */
 660                 id = has_commit_patch_id(commit, &ids);
 661                 if (!id)
 662                         continue;
 663                 id->seen = 1;
 664                 commit->object.flags |= cherry_flag;
 665         }
 666
 667         /* Now check the original side for seen ones */
 668         for (p = list; p; p = p->next) {
 669                 struct commit *commit = p->item;
 670                 struct patch_id *ent;
 671
 672                 ent = commit->util;
 673                 if (!ent)
 674                         continue;
 675                 if (ent->seen)
 676                         commit->object.flags |= cherry_flag;
 677                 commit->util = NULL;
 678         }
 679
 680         free_patch_ids(&ids);
 681 }
 682
 683 /* How many extra uninteresting commits we want to see.. */
 684 #define SLOP 5
 685
 686 static int still_interesting(struct commit_list *src, unsigned long date, int slop)
 687 {
 688         /*
 689          * No source list at all? We're definitely done..
 690          */
 691         if (!src)
 692                 return 0;
 693
 694         /*
 695          * Does the destination list contain entries with a date
 696          * before the source list? Definitely _not_ done.
 697          */
 698         if (date < src->item->date)
 699                 return SLOP;
 700
 701         /*
 702          * Does the source list still have interesting commits in
 703          * it? Definitely not done..
 704          */
 705         if (!everybody_uninteresting(src))
 706                 return SLOP;
 707
 708         /* Ok, we're closing in.. */
 709         return slop-1;
 710 }
 711
 712 /*
 713  * "rev-list --ancestry-path A..B" computes commits that are ancestors
 714  * of B but not ancestors of A but further limits the result to those
 715  * that are descendants of A.  This takes the list of bottom commits and
 716  * the result of "A..B" without --ancestry-path, and limits the latter
 717  * further to the ones that can reach one of the commits in "bottom".
 718  */
 719 static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *list)
 720 {
 721         struct commit_list *p;
 722         struct commit_list *rlist = NULL;
 723         int made_progress;
 724
 725         /*
 726          * Reverse the list so that it will be likely that we would
 727          * process parents before children.
 728          */
 729         for (p = list; p; p = p->next)
 730                 commit_list_insert(p->item, &rlist);
 731
 732         for (p = bottom; p; p = p->next)
 733                 p->item->object.flags |= TMP_MARK;
 734
 735         /*
 736          * Mark the ones that can reach bottom commits in "list",
 737          * in a bottom-up fashion.
 738          */
 739         do {
 740                 made_progress = 0;
 741                 for (p = rlist; p; p = p->next) {
 742                         struct commit *c = p->item;
 743                         struct commit_list *parents;
 744                         if (c->object.flags & (TMP_MARK | UNINTERESTING))
 745                                 continue;
 746                         for (parents = c->parents;
 747                              parents;
 748                              parents = parents->next) {
 749                                 if (!(parents->item->object.flags & TMP_MARK))
 750                                         continue;
 751                                 c->object.flags |= TMP_MARK;
 752                                 made_progress = 1;
 753                                 break;
 754                         }
 755                 }
 756         } while (made_progress);
 757
 758         /*
 759          * NEEDSWORK: decide if we want to remove parents that are
 760          * not marked with TMP_MARK from commit->parents for commits
 761          * in the resulting list.  We may not want to do that, though.
 762          */
 763
 764         /*
 765          * The ones that are not marked with TMP_MARK are uninteresting
 766          */
 767         for (p = list; p; p = p->next) {
 768                 struct commit *c = p->item;
 769                 if (c->object.flags & TMP_MARK)
 770                         continue;
 771                 c->object.flags |= UNINTERESTING;
 772         }
 773
 774         /* We are done with the TMP_MARK */
 775         for (p = list; p; p = p->next)
 776                 p->item->object.flags &= ~TMP_MARK;
 777         for (p = bottom; p; p = p->next)
 778                 p->item->object.flags &= ~TMP_MARK;
 779         free_commit_list(rlist);
 780 }
 781
 782 /*
 783  * Before walking the history, keep the set of "negative" refs the
 784  * caller has asked to exclude.
 785  *
 786  * This is used to compute "rev-list --ancestry-path A..B", as we need
 787  * to filter the result of "A..B" further to the ones that can actually
 788  * reach A.
 789  */
 790 static struct commit_list *collect_bottom_commits(struct rev_info *revs)
 791 {
 792         struct commit_list *bottom = NULL;
 793         int i;
 794         for (i = 0; i < revs->cmdline.nr; i++) {
 795                 struct rev_cmdline_entry *elem = &revs->cmdline.rev[i];
 796                 if ((elem->flags & UNINTERESTING) &&
 797                     elem->item->type == OBJ_COMMIT)
 798                         commit_list_insert((struct commit *)elem->item, &bottom);
 799         }
 800         return bottom;
 801 }
 802
 803 /* Assumes either left_only or right_only is set */
 804 static void limit_left_right(struct commit_list *list, struct rev_info *revs)
 805 {
 806         struct commit_list *p;
 807
 808         for (p = list; p; p = p->next) {
 809                 struct commit *commit = p->item;
 810
 811                 if (revs->right_only) {
 812                         if (commit->object.flags & SYMMETRIC_LEFT)
 813                                 commit->object.flags |= SHOWN;
 814                 } else  /* revs->left_only is set */
 815                         if (!(commit->object.flags & SYMMETRIC_LEFT))
 816                                 commit->object.flags |= SHOWN;
 817         }
 818 }
 819
 820 static int limit_list(struct rev_info *revs)
 821 {
 822         int slop = SLOP;
 823         unsigned long date = ~0ul;
 824         struct commit_list *list = revs->commits;
 825         struct commit_list *newlist = NULL;
 826         struct commit_list **p = &newlist;
 827         struct commit_list *bottom = NULL;
 828
 829         if (revs->ancestry_path) {
 830                 bottom = collect_bottom_commits(revs);
 831                 if (!bottom)
 832                         die("--ancestry-path given but there are no bottom commits");
 833         }
 834
 835         while (list) {
 836                 struct commit_list *entry = list;
 837                 struct commit *commit = list->item;
 838                 struct object *obj = &commit->object;
 839                 show_early_output_fn_t show;
 840
 841                 list = list->next;
 842                 free(entry);
 843
 844                 if (revs->max_age != -1 && (commit->date < revs->max_age))
 845                         obj->flags |= UNINTERESTING;
 846                 if (add_parents_to_list(revs, commit, &list, NULL) < 0)
 847                         return -1;
 848                 if (obj->flags & UNINTERESTING) {
 849                         mark_parents_uninteresting(commit);
 850                         if (revs->show_all)
 851                                 p = &commit_list_insert(commit, p)->next;
 852                         slop = still_interesting(list, date, slop);
 853                         if (slop)
 854                                 continue;
 855                         /* If showing all, add the whole pending list to the end */
 856                         if (revs->show_all)
 857                                 *p = list;
 858                         break;
 859                 }
 860                 if (revs->min_age != -1 && (commit->date > revs->min_age))
 861                         continue;
 862                 date = commit->date;
 863                 p = &commit_list_insert(commit, p)->next;
 864
 865                 show = show_early_output;
 866                 if (!show)
 867                         continue;
 868
 869                 show(revs, newlist);
 870                 show_early_output = NULL;
 871         }
 872         if (revs->cherry_pick || revs->cherry_mark)
 873                 cherry_pick_list(newlist, revs);
 874
 875         if (revs->left_only || revs->right_only)
 876                 limit_left_right(newlist, revs);
 877
 878         if (bottom) {
 879                 limit_to_ancestry(bottom, newlist);
 880                 free_commit_list(bottom);
 881         }
 882
 883         revs->commits = newlist;
 884         return 0;
 885 }
 886
 887 static void add_rev_cmdline(struct rev_info *revs,
 888                             struct object *item,
 889                             const char *name,
 890                             int whence,
 891                             unsigned flags)
 892 {
 893         struct rev_cmdline_info *info = &revs->cmdline;
 894         int nr = info->nr;
 895
 896         ALLOC_GROW(info->rev, nr + 1, info->alloc);
 897         info->rev[nr].item = item;
 898         info->rev[nr].name = name;
 899         info->rev[nr].whence = whence;
 900         info->rev[nr].flags = flags;
 901         info->nr++;
 902 }
 903
 904 struct all_refs_cb {
 905         int all_flags;
 906         int warned_bad_reflog;
 907         struct rev_info *all_revs;
 908         const char *name_for_errormsg;
 909 };
 910
 911 static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 912 {
 913         struct all_refs_cb *cb = cb_data;
 914         struct object *object = get_reference(cb->all_revs, path, sha1,
 915                                               cb->all_flags);
 916         add_rev_cmdline(cb->all_revs, object, path, REV_CMD_REF, cb->all_flags);
 917         add_pending_sha1(cb->all_revs, path, sha1, cb->all_flags);
 918         return 0;
 919 }
 920
 921 static void init_all_refs_cb(struct all_refs_cb *cb, struct rev_info *revs,
 922         unsigned flags)
 923 {
 924         cb->all_revs = revs;
 925         cb->all_flags = flags;
 926 }
 927
 928 static void handle_refs(const char *submodule, struct rev_info *revs, unsigned flags,
 929                 int (*for_each)(const char *, each_ref_fn, void *))
 930 {
 931         struct all_refs_cb cb;
 932         init_all_refs_cb(&cb, revs, flags);
 933         for_each(submodule, handle_one_ref, &cb);
 934 }
 935
 936 static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
 937 {
 938         struct all_refs_cb *cb = cb_data;
 939         if (!is_null_sha1(sha1)) {
 940                 struct object *o = parse_object(sha1);
 941                 if (o) {
 942                         o->flags |= cb->all_flags;
 943                         /* ??? CMDLINEFLAGS ??? */
 944                         add_pending_object(cb->all_revs, o, "");
 945                 }
 946                 else if (!cb->warned_bad_reflog) {
 947                         warning("reflog of '%s' references pruned commits",
 948                                 cb->name_for_errormsg);
 949                         cb->warned_bad_reflog = 1;
 950                 }
 951         }
 952 }
 953
 954 static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 955                 const char *email, unsigned long timestamp, int tz,
 956                 const char *message, void *cb_data)
 957 {
 958         handle_one_reflog_commit(osha1, cb_data);
 959         handle_one_reflog_commit(nsha1, cb_data);
 960         return 0;
 961 }
 962
 963 static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 964 {
 965         struct all_refs_cb *cb = cb_data;
 966         cb->warned_bad_reflog = 0;
 967         cb->name_for_errormsg = path;
 968         for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
 969         return 0;
 970 }
 971
 972 static void handle_reflog(struct rev_info *revs, unsigned flags)
 973 {
 974         struct all_refs_cb cb;
 975         cb.all_revs = revs;
 976         cb.all_flags = flags;
 977         for_each_reflog(handle_one_reflog, &cb);
 978 }
 979
 980 static int add_parents_only(struct rev_info *revs, const char *arg_, int flags)
 981 {
 982         unsigned char sha1[20];
 983         struct object *it;
 984         struct commit *commit;
 985         struct commit_list *parents;
 986         const char *arg = arg_;
 987
 988         if (*arg == '^') {
 989                 flags ^= UNINTERESTING;
 990                 arg++;
 991         }
 992         if (get_sha1(arg, sha1))
 993                 return 0;
 994         while (1) {
 995                 it = get_reference(revs, arg, sha1, 0);
 996                 if (!it && revs->ignore_missing)
 997                         return 0;
 998                 if (it->type != OBJ_TAG)
 999                         break;
1000                 if (!((struct tag*)it)->tagged)
1001                         return 0;
1002                 hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
1003         }
1004         if (it->type != OBJ_COMMIT)
1005                 return 0;
1006         commit = (struct commit *)it;
1007         for (parents = commit->parents; parents; parents = parents->next) {
1008                 it = &parents->item->object;
1009                 it->flags |= flags;
1010                 add_rev_cmdline(revs, it, arg_, REV_CMD_PARENTS_ONLY, flags);
1011                 add_pending_object(revs, it, arg);
1012         }
1013         return 1;
1014 }
1015
1016 void init_revisions(struct rev_info *revs, const char *prefix)
1017 {
1018         memset(revs, 0, sizeof(*revs));
1019
1020         revs->abbrev = DEFAULT_ABBREV;
1021         revs->ignore_merges = 1;
1022         revs->simplify_history = 1;
1023         DIFF_OPT_SET(&revs->pruning, RECURSIVE);
1024         DIFF_OPT_SET(&revs->pruning, QUICK);
1025         revs->pruning.add_remove = file_add_remove;
1026         revs->pruning.change = file_change;
1027         revs->lifo = 1;
1028         revs->dense = 1;
1029         revs->prefix = prefix;
1030         revs->max_age = -1;
1031         revs->min_age = -1;
1032         revs->skip_count = -1;
1033         revs->max_count = -1;
1034         revs->max_parents = -1;
1035
1036         revs->commit_format = CMIT_FMT_DEFAULT;
1037
1038         revs->grep_filter.status_only = 1;
1039         revs->grep_filter.pattern_tail = &(revs->grep_filter.pattern_list);
1040         revs->grep_filter.header_tail = &(revs->grep_filter.header_list);
1041         revs->grep_filter.regflags = REG_NEWLINE;
1042
1043         diff_setup(&revs->diffopt);
1044         if (prefix && !revs->diffopt.prefix) {
1045                 revs->diffopt.prefix = prefix;
1046                 revs->diffopt.prefix_length = strlen(prefix);
1047         }
1048
1049         revs->notes_opt.use_default_notes = -1;
1050 }
1051
1052 static void add_pending_commit_list(struct rev_info *revs,
1053                                     struct commit_list *commit_list,
1054                                     unsigned int flags)
1055 {
1056         while (commit_list) {
1057                 struct object *object = &commit_list->item->object;
1058                 object->flags |= flags;
1059                 add_pending_object(revs, object, sha1_to_hex(object->sha1));
1060                 commit_list = commit_list->next;
1061         }
1062 }
1063
1064 static void prepare_show_merge(struct rev_info *revs)
1065 {
1066         struct commit_list *bases;
1067         struct commit *head, *other;
1068         unsigned char sha1[20];
1069         const char **prune = NULL;
1070         int i, prune_num = 1; /* counting terminating NULL */
1071
1072         if (get_sha1("HEAD", sha1))
1073                 die("--merge without HEAD?");
1074         head = lookup_commit_or_die(sha1, "HEAD");
1075         if (get_sha1("MERGE_HEAD", sha1))
1076                 die("--merge without MERGE_HEAD?");
1077         other = lookup_commit_or_die(sha1, "MERGE_HEAD");
1078         add_pending_object(revs, &head->object, "HEAD");
1079         add_pending_object(revs, &other->object, "MERGE_HEAD");
1080         bases = get_merge_bases(head, other, 1);
1081         add_pending_commit_list(revs, bases, UNINTERESTING);
1082         free_commit_list(bases);
1083         head->object.flags |= SYMMETRIC_LEFT;
1084
1085         if (!active_nr)
1086                 read_cache();
1087         for (i = 0; i < active_nr; i++) {
1088                 struct cache_entry *ce = active_cache[i];
1089                 if (!ce_stage(ce))
1090                         continue;
1091                 if (ce_path_match(ce, &revs->prune_data)) {
1092                         prune_num++;
1093                         prune = xrealloc(prune, sizeof(*prune) * prune_num);
1094                         prune[prune_num-2] = ce->name;
1095                         prune[prune_num-1] = NULL;
1096                 }
1097                 while ((i+1 < active_nr) &&
1098                        ce_same_name(ce, active_cache[i+1]))
1099                         i++;
1100         }
1101         free_pathspec(&revs->prune_data);
1102         init_pathspec(&revs->prune_data, prune);
1103         revs->limited = 1;
1104 }
1105
1106 int handle_revision_arg(const char *arg_, struct rev_info *revs,
1107                         int flags,
1108                         int cant_be_filename)
1109 {
1110         unsigned mode;
1111         char *dotdot;
1112         struct object *object;
1113         unsigned char sha1[20];
1114         int local_flags;
1115         const char *arg = arg_;
1116
1117         dotdot = strstr(arg, "..");
1118         if (dotdot) {
1119                 unsigned char from_sha1[20];
1120                 const char *next = dotdot + 2;
1121                 const char *this = arg;
1122                 int symmetric = *next == '.';
1123                 unsigned int flags_exclude = flags ^ UNINTERESTING;
1124                 unsigned int a_flags;
1125
1126                 *dotdot = 0;
1127                 next += symmetric;
1128
1129                 if (!*next)
1130                         next = "HEAD";
1131                 if (dotdot == arg)
1132                         this = "HEAD";
1133                 if (!get_sha1(this, from_sha1) &&
1134                     !get_sha1(next, sha1)) {
1135                         struct commit *a, *b;
1136                         struct commit_list *exclude;
1137
1138                         a = lookup_commit_reference(from_sha1);
1139                         b = lookup_commit_reference(sha1);
1140                         if (!a || !b) {
1141                                 if (revs->ignore_missing)
1142                                         return 0;
1143                                 die(symmetric ?
1144                                     "Invalid symmetric difference expression %s...%s" :
1145                                     "Invalid revision range %s..%s",
1146                                     arg, next);
1147                         }
1148
1149                         if (!cant_be_filename) {
1150                                 *dotdot = '.';
1151                                 verify_non_filename(revs->prefix, arg);
1152                         }
1153
1154                         if (symmetric) {
1155                                 exclude = get_merge_bases(a, b, 1);
1156                                 add_pending_commit_list(revs, exclude,
1157                                                         flags_exclude);
1158                                 free_commit_list(exclude);
1159                                 a_flags = flags | SYMMETRIC_LEFT;
1160                         } else
1161                                 a_flags = flags_exclude;
1162                         a->object.flags |= a_flags;
1163                         b->object.flags |= flags;
1164                         add_rev_cmdline(revs, &a->object, this,
1165                                         REV_CMD_LEFT, a_flags);
1166                         add_rev_cmdline(revs, &b->object, next,
1167                                         REV_CMD_RIGHT, flags);
1168                         add_pending_object(revs, &a->object, this);
1169                         add_pending_object(revs, &b->object, next);
1170                         return 0;
1171                 }
1172                 *dotdot = '.';
1173         }
1174         dotdot = strstr(arg, "^@");
1175         if (dotdot && !dotdot[2]) {
1176                 *dotdot = 0;
1177                 if (add_parents_only(revs, arg, flags))
1178                         return 0;
1179                 *dotdot = '^';
1180         }
1181         dotdot = strstr(arg, "^!");
1182         if (dotdot && !dotdot[2]) {
1183                 *dotdot = 0;
1184                 if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
1185                         *dotdot = '^';
1186         }
1187
1188         local_flags = 0;
1189         if (*arg == '^') {
1190                 local_flags = UNINTERESTING;
1191                 arg++;
1192         }
1193         if (get_sha1_with_mode(arg, sha1, &mode))
1194                 return revs->ignore_missing ? 0 : -1;
1195         if (!cant_be_filename)
1196                 verify_non_filename(revs->prefix, arg);
1197         object = get_reference(revs, arg, sha1, flags ^ local_flags);
1198         add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
1199         add_pending_object_with_mode(revs, object, arg, mode);
1200         return 0;
1201 }
1202
1203 struct cmdline_pathspec {
1204         int alloc;
1205         int nr;
1206         const char **path;
1207 };
1208
1209 static void append_prune_data(struct cmdline_pathspec *prune, const char **av)
1210 {
1211         while (*av) {
1212                 ALLOC_GROW(prune->path, prune->nr+1, prune->alloc);
1213                 prune->path[prune->nr++] = *(av++);
1214         }
1215 }
1216
1217 static void read_pathspec_from_stdin(struct rev_info *revs, struct strbuf *sb,
1218                                      struct cmdline_pathspec *prune)
1219 {
1220         while (strbuf_getwholeline(sb, stdin, '\n') != EOF) {
1221                 int len = sb->len;
1222                 if (len && sb->buf[len - 1] == '\n')
1223                         sb->buf[--len] = '\0';
1224                 ALLOC_GROW(prune->path, prune->nr+1, prune->alloc);
1225                 prune->path[prune->nr++] = xstrdup(sb->buf);
1226         }
1227 }
1228
1229 static void read_revisions_from_stdin(struct rev_info *revs,
1230                                       struct cmdline_pathspec *prune)
1231 {
1232         struct strbuf sb;
1233         int seen_dashdash = 0;
1234
1235         strbuf_init(&sb, 1000);
1236         while (strbuf_getwholeline(&sb, stdin, '\n') != EOF) {
1237                 int len = sb.len;
1238                 if (len && sb.buf[len - 1] == '\n')
1239                         sb.buf[--len] = '\0';
1240                 if (!len)
1241                         break;
1242                 if (sb.buf[0] == '-') {
1243                         if (len == 2 && sb.buf[1] == '-') {
1244                                 seen_dashdash = 1;
1245                                 break;
1246                         }
1247                         die("options not supported in --stdin mode");
1248                 }
1249                 if (handle_revision_arg(sb.buf, revs, 0, 1))
1250                         die("bad revision '%s'", sb.buf);
1251         }
1252         if (seen_dashdash)
1253                 read_pathspec_from_stdin(revs, &sb, prune);
1254         strbuf_release(&sb);
1255 }
1256
1257 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
1258 {
1259         append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
1260 }
1261
1262 static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
1263 {
1264         append_header_grep_pattern(&revs->grep_filter, field, pattern);
1265 }
1266
1267 static void add_message_grep(struct rev_info *revs, const char *pattern)
1268 {
1269         add_grep(revs, pattern, GREP_PATTERN_BODY);
1270 }
1271
1272 static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
1273                                int *unkc, const char **unkv)
1274 {
1275         const char *arg = argv[0];
1276         const char *optarg;
1277         int argcount;
1278
1279         /* pseudo revision arguments */
1280         if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
1281             !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
1282             !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
1283             !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
1284             !strcmp(arg, "--bisect") || !prefixcmp(arg, "--glob=") ||
1285             !prefixcmp(arg, "--branches=") || !prefixcmp(arg, "--tags=") ||
1286             !prefixcmp(arg, "--remotes="))
1287         {
1288                 unkv[(*unkc)++] = arg;
1289                 return 1;
1290         }
1291
1292         if ((argcount = parse_long_opt("max-count", argv, &optarg))) {
1293                 revs->max_count = atoi(optarg);
1294                 revs->no_walk = 0;
1295                 return argcount;
1296         } else if ((argcount = parse_long_opt("skip", argv, &optarg))) {
1297                 revs->skip_count = atoi(optarg);
1298                 return argcount;
1299         } else if ((*arg == '-') && isdigit(arg[1])) {
1300         /* accept -<digit>, like traditional "head" */
1301                 revs->max_count = atoi(arg + 1);
1302                 revs->no_walk = 0;
1303         } else if (!strcmp(arg, "-n")) {
1304                 if (argc <= 1)
1305                         return error("-n requires an argument");
1306                 revs->max_count = atoi(argv[1]);
1307                 revs->no_walk = 0;
1308                 return 2;
1309         } else if (!prefixcmp(arg, "-n")) {
1310                 revs->max_count = atoi(arg + 2);
1311                 revs->no_walk = 0;
1312         } else if ((argcount = parse_long_opt("max-age", argv, &optarg))) {
1313                 revs->max_age = atoi(optarg);
1314                 return argcount;
1315         } else if ((argcount = parse_long_opt("since", argv, &optarg))) {
1316                 revs->max_age = approxidate(optarg);
1317                 return argcount;
1318         } else if ((argcount = parse_long_opt("after", argv, &optarg))) {
1319                 revs->max_age = approxidate(optarg);
1320                 return argcount;
1321         } else if ((argcount = parse_long_opt("min-age", argv, &optarg))) {
1322                 revs->min_age = atoi(optarg);
1323                 return argcount;
1324         } else if ((argcount = parse_long_opt("before", argv, &optarg))) {
1325                 revs->min_age = approxidate(optarg);
1326                 return argcount;
1327         } else if ((argcount = parse_long_opt("until", argv, &optarg))) {
1328                 revs->min_age = approxidate(optarg);
1329                 return argcount;
1330         } else if (!strcmp(arg, "--first-parent")) {
1331                 revs->first_parent_only = 1;
1332         } else if (!strcmp(arg, "--ancestry-path")) {
1333                 revs->ancestry_path = 1;
1334                 revs->simplify_history = 0;
1335                 revs->limited = 1;
1336         } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
1337                 init_reflog_walk(&revs->reflog_info);
1338         } else if (!strcmp(arg, "--default")) {
1339                 if (argc <= 1)
1340                         return error("bad --default argument");
1341                 revs->def = argv[1];
1342                 return 2;
1343         } else if (!strcmp(arg, "--merge")) {
1344                 revs->show_merge = 1;
1345         } else if (!strcmp(arg, "--topo-order")) {
1346                 revs->lifo = 1;
1347                 revs->topo_order = 1;
1348         } else if (!strcmp(arg, "--simplify-merges")) {
1349                 revs->simplify_merges = 1;
1350                 revs->rewrite_parents = 1;
1351                 revs->simplify_history = 0;
1352                 revs->limited = 1;
1353         } else if (!strcmp(arg, "--simplify-by-decoration")) {
1354                 revs->simplify_merges = 1;
1355                 revs->rewrite_parents = 1;
1356                 revs->simplify_history = 0;
1357                 revs->simplify_by_decoration = 1;
1358                 revs->limited = 1;
1359                 revs->prune = 1;
1360                 load_ref_decorations(DECORATE_SHORT_REFS);
1361         } else if (!strcmp(arg, "--date-order")) {
1362                 revs->lifo = 0;
1363                 revs->topo_order = 1;
1364         } else if (!prefixcmp(arg, "--early-output")) {
1365                 int count = 100;
1366                 switch (arg[14]) {
1367                 case '=':
1368                         count = atoi(arg+15);
1369                         /* Fallthrough */
1370                 case 0:
1371                         revs->topo_order = 1;
1372                        revs->early_output = count;
1373                 }
1374         } else if (!strcmp(arg, "--parents")) {
1375                 revs->rewrite_parents = 1;
1376                 revs->print_parents = 1;
1377         } else if (!strcmp(arg, "--dense")) {
1378                 revs->dense = 1;
1379         } else if (!strcmp(arg, "--sparse")) {
1380                 revs->dense = 0;
1381         } else if (!strcmp(arg, "--show-all")) {
1382                 revs->show_all = 1;
1383         } else if (!strcmp(arg, "--remove-empty")) {
1384                 revs->remove_empty_trees = 1;
1385         } else if (!strcmp(arg, "--merges")) {
1386                 revs->min_parents = 2;
1387         } else if (!strcmp(arg, "--no-merges")) {
1388                 revs->max_parents = 1;
1389         } else if (!prefixcmp(arg, "--min-parents=")) {
1390                 revs->min_parents = atoi(arg+14);
1391         } else if (!prefixcmp(arg, "--no-min-parents")) {
1392                 revs->min_parents = 0;
1393         } else if (!prefixcmp(arg, "--max-parents=")) {
1394                 revs->max_parents = atoi(arg+14);
1395         } else if (!prefixcmp(arg, "--no-max-parents")) {
1396                 revs->max_parents = -1;
1397         } else if (!strcmp(arg, "--boundary")) {
1398                 revs->boundary = 1;
1399         } else if (!strcmp(arg, "--left-right")) {
1400                 revs->left_right = 1;
1401         } else if (!strcmp(arg, "--left-only")) {
1402                 if (revs->right_only)
1403                         die("--left-only is incompatible with --right-only"
1404                             " or --cherry");
1405                 revs->left_only = 1;
1406         } else if (!strcmp(arg, "--right-only")) {
1407                 if (revs->left_only)
1408                         die("--right-only is incompatible with --left-only");
1409                 revs->right_only = 1;
1410         } else if (!strcmp(arg, "--cherry")) {
1411                 if (revs->left_only)
1412                         die("--cherry is incompatible with --left-only");
1413                 revs->cherry_mark = 1;
1414                 revs->right_only = 1;
1415                 revs->max_parents = 1;
1416                 revs->limited = 1;
1417         } else if (!strcmp(arg, "--count")) {
1418                 revs->count = 1;
1419         } else if (!strcmp(arg, "--cherry-mark")) {
1420                 if (revs->cherry_pick)
1421                         die("--cherry-mark is incompatible with --cherry-pick");
1422                 revs->cherry_mark = 1;
1423                 revs->limited = 1; /* needs limit_list() */
1424         } else if (!strcmp(arg, "--cherry-pick")) {
1425                 if (revs->cherry_mark)
1426                         die("--cherry-pick is incompatible with --cherry-mark");
1427                 revs->cherry_pick = 1;
1428                 revs->limited = 1;
1429         } else if (!strcmp(arg, "--objects")) {
1430                 revs->tag_objects = 1;
1431                 revs->tree_objects = 1;
1432                 revs->blob_objects = 1;
1433         } else if (!strcmp(arg, "--objects-edge")) {
1434                 revs->tag_objects = 1;
1435                 revs->tree_objects = 1;
1436                 revs->blob_objects = 1;
1437                 revs->edge_hint = 1;
1438         } else if (!strcmp(arg, "--verify-objects")) {
1439                 revs->tag_objects = 1;
1440                 revs->tree_objects = 1;
1441                 revs->blob_objects = 1;
1442                 revs->verify_objects = 1;
1443         } else if (!strcmp(arg, "--unpacked")) {
1444                 revs->unpacked = 1;
1445         } else if (!prefixcmp(arg, "--unpacked=")) {
1446                 die("--unpacked=<packfile> no longer supported.");
1447         } else if (!strcmp(arg, "-r")) {
1448                 revs->diff = 1;
1449                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1450         } else if (!strcmp(arg, "-t")) {
1451                 revs->diff = 1;
1452                 DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1453                 DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1454         } else if (!strcmp(arg, "-m")) {
1455                 revs->ignore_merges = 0;
1456         } else if (!strcmp(arg, "-c")) {
1457                 revs->diff = 1;
1458                 revs->dense_combined_merges = 0;
1459                 revs->combine_merges = 1;
1460         } else if (!strcmp(arg, "--cc")) {
1461                 revs->diff = 1;
1462                 revs->dense_combined_merges = 1;
1463                 revs->combine_merges = 1;
1464         } else if (!strcmp(arg, "-v")) {
1465                 revs->verbose_header = 1;
1466         } else if (!strcmp(arg, "--pretty")) {
1467                 revs->verbose_header = 1;
1468                 revs->pretty_given = 1;
1469                 get_commit_format(arg+8, revs);
1470         } else if (!prefixcmp(arg, "--pretty=") || !prefixcmp(arg, "--format=")) {
1471                 /*
1472                  * Detached form ("--pretty X" as opposed to "--pretty=X")
1473                  * not allowed, since the argument is optional.
1474                  */
1475                 revs->verbose_header = 1;
1476                 revs->pretty_given = 1;
1477                 get_commit_format(arg+9, revs);
1478         } else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
1479                 revs->show_notes = 1;
1480                 revs->show_notes_given = 1;
1481                 revs->notes_opt.use_default_notes = 1;
1482         } else if (!strcmp(arg, "--show-signature")) {
1483                 revs->show_signature = 1;
1484         } else if (!prefixcmp(arg, "--show-notes=") ||
1485                    !prefixcmp(arg, "--notes=")) {
1486                 struct strbuf buf = STRBUF_INIT;
1487                 revs->show_notes = 1;
1488                 revs->show_notes_given = 1;
1489                 if (!prefixcmp(arg, "--show-notes")) {
1490                         if (revs->notes_opt.use_default_notes < 0)
1491                                 revs->notes_opt.use_default_notes = 1;
1492                         strbuf_addstr(&buf, arg+13);
1493                 }
1494                 else
1495                         strbuf_addstr(&buf, arg+8);
1496                 expand_notes_ref(&buf);
1497                 string_list_append(&revs->notes_opt.extra_notes_refs,
1498                                    strbuf_detach(&buf, NULL));
1499         } else if (!strcmp(arg, "--no-notes")) {
1500                 revs->show_notes = 0;
1501                 revs->show_notes_given = 1;
1502                 revs->notes_opt.use_default_notes = -1;
1503                 /* we have been strdup'ing ourselves, so trick
1504                  * string_list into free()ing strings */
1505                 revs->notes_opt.extra_notes_refs.strdup_strings = 1;
1506                 string_list_clear(&revs->notes_opt.extra_notes_refs, 0);
1507                 revs->notes_opt.extra_notes_refs.strdup_strings = 0;
1508         } else if (!strcmp(arg, "--standard-notes")) {
1509                 revs->show_notes_given = 1;
1510                 revs->notes_opt.use_default_notes = 1;
1511         } else if (!strcmp(arg, "--no-standard-notes")) {
1512                 revs->notes_opt.use_default_notes = 0;
1513         } else if (!strcmp(arg, "--oneline")) {
1514                 revs->verbose_header = 1;
1515                 get_commit_format("oneline", revs);
1516                 revs->pretty_given = 1;
1517                 revs->abbrev_commit = 1;
1518         } else if (!strcmp(arg, "--graph")) {
1519                 revs->topo_order = 1;
1520                 revs->rewrite_parents = 1;
1521                 revs->graph = graph_init(revs);
1522         } else if (!strcmp(arg, "--root")) {
1523                 revs->show_root_diff = 1;
1524         } else if (!strcmp(arg, "--no-commit-id")) {
1525                 revs->no_commit_id = 1;
1526         } else if (!strcmp(arg, "--always")) {
1527                 revs->always_show_header = 1;
1528         } else if (!strcmp(arg, "--no-abbrev")) {
1529                 revs->abbrev = 0;
1530         } else if (!strcmp(arg, "--abbrev")) {
1531                 revs->abbrev = DEFAULT_ABBREV;
1532         } else if (!prefixcmp(arg, "--abbrev=")) {
1533                 revs->abbrev = strtoul(arg + 9, NULL, 10);
1534                 if (revs->abbrev < MINIMUM_ABBREV)
1535                         revs->abbrev = MINIMUM_ABBREV;
1536                 else if (revs->abbrev > 40)
1537                         revs->abbrev = 40;
1538         } else if (!strcmp(arg, "--abbrev-commit")) {
1539                 revs->abbrev_commit = 1;
1540                 revs->abbrev_commit_given = 1;
1541         } else if (!strcmp(arg, "--no-abbrev-commit")) {
1542                 revs->abbrev_commit = 0;
1543         } else if (!strcmp(arg, "--full-diff")) {
1544                 revs->diff = 1;
1545                 revs->full_diff = 1;
1546         } else if (!strcmp(arg, "--full-history")) {
1547                 revs->simplify_history = 0;
1548         } else if (!strcmp(arg, "--relative-date")) {
1549                 revs->date_mode = DATE_RELATIVE;
1550                 revs->date_mode_explicit = 1;
1551         } else if ((argcount = parse_long_opt("date", argv, &optarg))) {
1552                 revs->date_mode = parse_date_format(optarg);
1553                 revs->date_mode_explicit = 1;
1554                 return argcount;
1555         } else if (!strcmp(arg, "--log-size")) {
1556                 revs->show_log_size = 1;
1557         }
1558         /*
1559          * Grepping the commit log
1560          */
1561         else if ((argcount = parse_long_opt("author", argv, &optarg))) {
1562                 add_header_grep(revs, GREP_HEADER_AUTHOR, optarg);
1563                 return argcount;
1564         } else if ((argcount = parse_long_opt("committer", argv, &optarg))) {
1565                 add_header_grep(revs, GREP_HEADER_COMMITTER, optarg);
1566                 return argcount;
1567         } else if ((argcount = parse_long_opt("grep", argv, &optarg))) {
1568                 add_message_grep(revs, optarg);
1569                 return argcount;
1570         } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
1571                 revs->grep_filter.regflags |= REG_EXTENDED;
1572         } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
1573                 revs->grep_filter.regflags |= REG_ICASE;
1574         } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
1575                 revs->grep_filter.fixed = 1;
1576         } else if (!strcmp(arg, "--all-match")) {
1577                 revs->grep_filter.all_match = 1;
1578         } else if ((argcount = parse_long_opt("encoding", argv, &optarg))) {
1579                 if (strcmp(optarg, "none"))
1580                         git_log_output_encoding = xstrdup(optarg);
1581                 else
1582                         git_log_output_encoding = "";
1583                 return argcount;
1584         } else if (!strcmp(arg, "--reverse")) {
1585                 revs->reverse ^= 1;
1586         } else if (!strcmp(arg, "--children")) {
1587                 revs->children.name = "children";
1588                 revs->limited = 1;
1589         } else if (!strcmp(arg, "--ignore-missing")) {
1590                 revs->ignore_missing = 1;
1591         } else {
1592                 int opts = diff_opt_parse(&revs->diffopt, argv, argc);
1593                 if (!opts)
1594                         unkv[(*unkc)++] = arg;
1595                 return opts;
1596         }
1597
1598         return 1;
1599 }
1600
1601 void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
1602                         const struct option *options,
1603                         const char * const usagestr[])
1604 {
1605         int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
1606                                     &ctx->cpidx, ctx->out);
1607         if (n <= 0) {
1608                 error("unknown option `%s'", ctx->argv[0]);
1609                 usage_with_options(usagestr, options);
1610         }
1611         ctx->argv += n;
1612         ctx->argc -= n;
1613 }
1614
1615 static int for_each_bad_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1616 {
1617         return for_each_ref_in_submodule(submodule, "refs/bisect/bad", fn, cb_data);
1618 }
1619
1620 static int for_each_good_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1621 {
1622         return for_each_ref_in_submodule(submodule, "refs/bisect/good", fn, cb_data);
1623 }
1624
1625 static int handle_revision_pseudo_opt(const char *submodule,
1626                                 struct rev_info *revs,
1627                                 int argc, const char **argv, int *flags)
1628 {
1629         const char *arg = argv[0];
1630         const char *optarg;
1631         int argcount;
1632
1633         /*
1634          * NOTE!
1635          *
1636          * Commands like "git shortlog" will not accept the options below
1637          * unless parse_revision_opt queues them (as opposed to erroring
1638          * out).
1639          *
1640          * When implementing your new pseudo-option, remember to
1641          * register it in the list at the top of handle_revision_opt.
1642          */
1643         if (!strcmp(arg, "--all")) {
1644                 handle_refs(submodule, revs, *flags, for_each_ref_submodule);
1645                 handle_refs(submodule, revs, *flags, head_ref_submodule);
1646         } else if (!strcmp(arg, "--branches")) {
1647                 handle_refs(submodule, revs, *flags, for_each_branch_ref_submodule);
1648         } else if (!strcmp(arg, "--bisect")) {
1649                 handle_refs(submodule, revs, *flags, for_each_bad_bisect_ref);
1650                 handle_refs(submodule, revs, *flags ^ UNINTERESTING, for_each_good_bisect_ref);
1651                 revs->bisect = 1;
1652         } else if (!strcmp(arg, "--tags")) {
1653                 handle_refs(submodule, revs, *flags, for_each_tag_ref_submodule);
1654         } else if (!strcmp(arg, "--remotes")) {
1655                 handle_refs(submodule, revs, *flags, for_each_remote_ref_submodule);
1656         } else if ((argcount = parse_long_opt("glob", argv, &optarg))) {
1657                 struct all_refs_cb cb;
1658                 init_all_refs_cb(&cb, revs, *flags);
1659                 for_each_glob_ref(handle_one_ref, optarg, &cb);
1660                 return argcount;
1661         } else if (!prefixcmp(arg, "--branches=")) {
1662                 struct all_refs_cb cb;
1663                 init_all_refs_cb(&cb, revs, *flags);
1664                 for_each_glob_ref_in(handle_one_ref, arg + 11, "refs/heads/", &cb);
1665         } else if (!prefixcmp(arg, "--tags=")) {
1666                 struct all_refs_cb cb;
1667                 init_all_refs_cb(&cb, revs, *flags);
1668                 for_each_glob_ref_in(handle_one_ref, arg + 7, "refs/tags/", &cb);
1669         } else if (!prefixcmp(arg, "--remotes=")) {
1670                 struct all_refs_cb cb;
1671                 init_all_refs_cb(&cb, revs, *flags);
1672                 for_each_glob_ref_in(handle_one_ref, arg + 10, "refs/remotes/", &cb);
1673         } else if (!strcmp(arg, "--reflog")) {
1674                 handle_reflog(revs, *flags);
1675         } else if (!strcmp(arg, "--not")) {
1676                 *flags ^= UNINTERESTING;
1677         } else if (!strcmp(arg, "--no-walk")) {
1678                 revs->no_walk = 1;
1679         } else if (!strcmp(arg, "--do-walk")) {
1680                 revs->no_walk = 0;
1681         } else {
1682                 return 0;
1683         }
1684
1685         return 1;
1686 }
1687
1688 /*
1689  * Parse revision information, filling in the "rev_info" structure,
1690  * and removing the used arguments from the argument list.
1691  *
1692  * Returns the number of arguments left that weren't recognized
1693  * (which are also moved to the head of the argument list)
1694  */
1695 int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
1696 {
1697         int i, flags, left, seen_dashdash, read_from_stdin, got_rev_arg = 0;
1698         struct cmdline_pathspec prune_data;
1699         const char *submodule = NULL;
1700
1701         memset(&prune_data, 0, sizeof(prune_data));
1702         if (opt)
1703                 submodule = opt->submodule;
1704
1705         /* First, search for "--" */
1706         seen_dashdash = 0;
1707         for (i = 1; i < argc; i++) {
1708                 const char *arg = argv[i];
1709                 if (strcmp(arg, "--"))
1710                         continue;
1711                 argv[i] = NULL;
1712                 argc = i;
1713                 if (argv[i + 1])
1714                         append_prune_data(&prune_data, argv + i + 1);
1715                 seen_dashdash = 1;
1716                 break;
1717         }
1718
1719         /* Second, deal with arguments and options */
1720         flags = 0;
1721         read_from_stdin = 0;
1722         for (left = i = 1; i < argc; i++) {
1723                 const char *arg = argv[i];
1724                 if (*arg == '-') {
1725                         int opts;
1726
1727                         opts = handle_revision_pseudo_opt(submodule,
1728                                                 revs, argc - i, argv + i,
1729                                                 &flags);
1730                         if (opts > 0) {
1731                                 i += opts - 1;
1732                                 continue;
1733                         }
1734
1735                         if (!strcmp(arg, "--stdin")) {
1736                                 if (revs->disable_stdin) {
1737                                         argv[left++] = arg;
1738                                         continue;
1739                                 }
1740                                 if (read_from_stdin++)
1741                                         die("--stdin given twice?");
1742                                 read_revisions_from_stdin(revs, &prune_data);
1743                                 continue;
1744                         }
1745
1746                         opts = handle_revision_opt(revs, argc - i, argv + i, &left, argv);
1747                         if (opts > 0) {
1748                                 i += opts - 1;
1749                                 continue;
1750                         }
1751                         if (opts < 0)
1752                                 exit(128);
1753                         continue;
1754                 }
1755
1756                 if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
1757                         int j;
1758                         if (seen_dashdash || *arg == '^')
1759                                 die("bad revision '%s'", arg);
1760
1761                         /* If we didn't have a "--":
1762                          * (1) all filenames must exist;
1763                          * (2) all rev-args must not be interpretable
1764                          *     as a valid filename.
1765                          * but the latter we have checked in the main loop.
1766                          */
1767                         for (j = i; j < argc; j++)
1768                                 verify_filename(revs->prefix, argv[j]);
1769
1770                         append_prune_data(&prune_data, argv + i);
1771                         break;
1772                 }
1773                 else
1774                         got_rev_arg = 1;
1775         }
1776
1777         if (prune_data.nr) {
1778                 /*
1779                  * If we need to introduce the magic "a lone ':' means no
1780                  * pathspec whatsoever", here is the place to do so.
1781                  *
1782                  * if (prune_data.nr == 1 && !strcmp(prune_data[0], ":")) {
1783                  *      prune_data.nr = 0;
1784                  *      prune_data.alloc = 0;
1785                  *      free(prune_data.path);
1786                  *      prune_data.path = NULL;
1787                  * } else {
1788                  *      terminate prune_data.alloc with NULL and
1789                  *      call init_pathspec() to set revs->prune_data here.
1790                  * }
1791                  */
1792                 ALLOC_GROW(prune_data.path, prune_data.nr+1, prune_data.alloc);
1793                 prune_data.path[prune_data.nr++] = NULL;
1794                 init_pathspec(&revs->prune_data,
1795                               get_pathspec(revs->prefix, prune_data.path));
1796         }
1797
1798         if (revs->def == NULL)
1799                 revs->def = opt ? opt->def : NULL;
1800         if (opt && opt->tweak)
1801                 opt->tweak(revs, opt);
1802         if (revs->show_merge)
1803                 prepare_show_merge(revs);
1804         if (revs->def && !revs->pending.nr && !got_rev_arg) {
1805                 unsigned char sha1[20];
1806                 struct object *object;
1807                 unsigned mode;
1808                 if (get_sha1_with_mode(revs->def, sha1, &mode))
1809                         die("bad default revision '%s'", revs->def);
1810                 object = get_reference(revs, revs->def, sha1, 0);
1811                 add_pending_object_with_mode(revs, object, revs->def, mode);
1812         }
1813
1814         /* Did the user ask for any diff output? Run the diff! */
1815         if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
1816                 revs->diff = 1;
1817
1818         /* Pickaxe, diff-filter and rename following need diffs */
1819         if (revs->diffopt.pickaxe ||
1820             revs->diffopt.filter ||
1821             DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1822                 revs->diff = 1;
1823
1824         if (revs->topo_order)
1825                 revs->limited = 1;
1826
1827         if (revs->prune_data.nr) {
1828                 diff_tree_setup_paths(revs->prune_data.raw, &revs->pruning);
1829                 /* Can't prune commits with rename following: the paths change.. */
1830                 if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1831                         revs->prune = 1;
1832                 if (!revs->full_diff)
1833                         diff_tree_setup_paths(revs->prune_data.raw, &revs->diffopt);
1834         }
1835         if (revs->combine_merges)
1836                 revs->ignore_merges = 0;
1837         revs->diffopt.abbrev = revs->abbrev;
1838         if (diff_setup_done(&revs->diffopt) < 0)
1839                 die("diff_setup_done failed");
1840
1841         compile_grep_patterns(&revs->grep_filter);
1842
1843         if (revs->reverse && revs->reflog_info)
1844                 die("cannot combine --reverse with --walk-reflogs");
1845         if (revs->rewrite_parents && revs->children.name)
1846                 die("cannot combine --parents and --children");
1847
1848         /*
1849          * Limitations on the graph functionality
1850          */
1851         if (revs->reverse && revs->graph)
1852                 die("cannot combine --reverse with --graph");
1853
1854         if (revs->reflog_info && revs->graph)
1855                 die("cannot combine --walk-reflogs with --graph");
1856
1857         return left;
1858 }
1859
1860 static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
1861 {
1862         struct commit_list *l = xcalloc(1, sizeof(*l));
1863
1864         l->item = child;
1865         l->next = add_decoration(&revs->children, &parent->object, l);
1866 }
1867
1868 static int remove_duplicate_parents(struct commit *commit)
1869 {
1870         struct commit_list **pp, *p;
1871         int surviving_parents;
1872
1873         /* Examine existing parents while marking ones we have seen... */
1874         pp = &commit->parents;
1875         while ((p = *pp) != NULL) {
1876                 struct commit *parent = p->item;
1877                 if (parent->object.flags & TMP_MARK) {
1878                         *pp = p->next;
1879                         continue;
1880                 }
1881                 parent->object.flags |= TMP_MARK;
1882                 pp = &p->next;
1883         }
1884         /* count them while clearing the temporary mark */
1885         surviving_parents = 0;
1886         for (p = commit->parents; p; p = p->next) {
1887                 p->item->object.flags &= ~TMP_MARK;
1888                 surviving_parents++;
1889         }
1890         return surviving_parents;
1891 }
1892
1893 struct merge_simplify_state {
1894         struct commit *simplified;
1895 };
1896
1897 static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
1898 {
1899         struct merge_simplify_state *st;
1900
1901         st = lookup_decoration(&revs->merge_simplification, &commit->object);
1902         if (!st) {
1903                 st = xcalloc(1, sizeof(*st));
1904                 add_decoration(&revs->merge_simplification, &commit->object, st);
1905         }
1906         return st;
1907 }
1908
1909 static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
1910 {
1911         struct commit_list *p;
1912         struct merge_simplify_state *st, *pst;
1913         int cnt;
1914
1915         st = locate_simplify_state(revs, commit);
1916
1917         /*
1918          * Have we handled this one?
1919          */
1920         if (st->simplified)
1921                 return tail;
1922
1923         /*
1924          * An UNINTERESTING commit simplifies to itself, so does a
1925          * root commit.  We do not rewrite parents of such commit
1926          * anyway.
1927          */
1928         if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
1929                 st->simplified = commit;
1930                 return tail;
1931         }
1932
1933         /*
1934          * Do we know what commit all of our parents should be rewritten to?
1935          * Otherwise we are not ready to rewrite this one yet.
1936          */
1937         for (cnt = 0, p = commit->parents; p; p = p->next) {
1938                 pst = locate_simplify_state(revs, p->item);
1939                 if (!pst->simplified) {
1940                         tail = &commit_list_insert(p->item, tail)->next;
1941                         cnt++;
1942                 }
1943         }
1944         if (cnt) {
1945                 tail = &commit_list_insert(commit, tail)->next;
1946                 return tail;
1947         }
1948
1949         /*
1950          * Rewrite our list of parents.
1951          */
1952         for (p = commit->parents; p; p = p->next) {
1953                 pst = locate_simplify_state(revs, p->item);
1954                 p->item = pst->simplified;
1955         }
1956         cnt = remove_duplicate_parents(commit);
1957
1958         /*
1959          * It is possible that we are a merge and one side branch
1960          * does not have any commit that touches the given paths;
1961          * in such a case, the immediate parents will be rewritten
1962          * to different commits.
1963          *
1964          *      o----X          X: the commit we are looking at;
1965          *     /    /           o: a commit that touches the paths;
1966          * ---o----'
1967          *
1968          * Further reduce the parents by removing redundant parents.
1969          */
1970         if (1 < cnt) {
1971                 struct commit_list *h = reduce_heads(commit->parents);
1972                 cnt = commit_list_count(h);
1973                 free_commit_list(commit->parents);
1974                 commit->parents = h;
1975         }
1976
1977         /*
1978          * A commit simplifies to itself if it is a root, if it is
1979          * UNINTERESTING, if it touches the given paths, or if it is a
1980          * merge and its parents simplifies to more than one commits
1981          * (the first two cases are already handled at the beginning of
1982          * this function).
1983          *
1984          * Otherwise, it simplifies to what its sole parent simplifies to.
1985          */
1986         if (!cnt ||
1987             (commit->object.flags & UNINTERESTING) ||
1988             !(commit->object.flags & TREESAME) ||
1989             (1 < cnt))
1990                 st->simplified = commit;
1991         else {
1992                 pst = locate_simplify_state(revs, commit->parents->item);
1993                 st->simplified = pst->simplified;
1994         }
1995         return tail;
1996 }
1997
1998 static void simplify_merges(struct rev_info *revs)
1999 {
2000         struct commit_list *list;
2001         struct commit_list *yet_to_do, **tail;
2002
2003         if (!revs->topo_order)
2004                 sort_in_topological_order(&revs->commits, revs->lifo);
2005         if (!revs->prune)
2006                 return;
2007
2008         /* feed the list reversed */
2009         yet_to_do = NULL;
2010         for (list = revs->commits; list; list = list->next)
2011                 commit_list_insert(list->item, &yet_to_do);
2012         while (yet_to_do) {
2013                 list = yet_to_do;
2014                 yet_to_do = NULL;
2015                 tail = &yet_to_do;
2016                 while (list) {
2017                         struct commit *commit = list->item;
2018                         struct commit_list *next = list->next;
2019                         free(list);
2020                         list = next;
2021                         tail = simplify_one(revs, commit, tail);
2022                 }
2023         }
2024
2025         /* clean up the result, removing the simplified ones */
2026         list = revs->commits;
2027         revs->commits = NULL;
2028         tail = &revs->commits;
2029         while (list) {
2030                 struct commit *commit = list->item;
2031                 struct commit_list *next = list->next;
2032                 struct merge_simplify_state *st;
2033                 free(list);
2034                 list = next;
2035                 st = locate_simplify_state(revs, commit);
2036                 if (st->simplified == commit)
2037                         tail = &commit_list_insert(commit, tail)->next;
2038         }
2039 }
2040
2041 static void set_children(struct rev_info *revs)
2042 {
2043         struct commit_list *l;
2044         for (l = revs->commits; l; l = l->next) {
2045                 struct commit *commit = l->item;
2046                 struct commit_list *p;
2047
2048                 for (p = commit->parents; p; p = p->next)
2049                         add_child(revs, p->item, commit);
2050         }
2051 }
2052
2053 int prepare_revision_walk(struct rev_info *revs)
2054 {
2055         int nr = revs->pending.nr;
2056         struct object_array_entry *e, *list;
2057
2058         e = list = revs->pending.objects;
2059         revs->pending.nr = 0;
2060         revs->pending.alloc = 0;
2061         revs->pending.objects = NULL;
2062         while (--nr >= 0) {
2063                 struct commit *commit = handle_commit(revs, e->item, e->name);
2064                 if (commit) {
2065                         if (!(commit->object.flags & SEEN)) {
2066                                 commit->object.flags |= SEEN;
2067                                 commit_list_insert_by_date(commit, &revs->commits);
2068                         }
2069                 }
2070                 e++;
2071         }
2072         if (!revs->leak_pending)
2073                 free(list);
2074
2075         if (revs->no_walk)
2076                 return 0;
2077         if (revs->limited)
2078                 if (limit_list(revs) < 0)
2079                         return -1;
2080         if (revs->topo_order)
2081                 sort_in_topological_order(&revs->commits, revs->lifo);
2082         if (revs->simplify_merges)
2083                 simplify_merges(revs);
2084         if (revs->children.name)
2085                 set_children(revs);
2086         return 0;
2087 }
2088
2089 enum rewrite_result {
2090         rewrite_one_ok,
2091         rewrite_one_noparents,
2092         rewrite_one_error
2093 };
2094
2095 static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
2096 {
2097         struct commit_list *cache = NULL;
2098
2099         for (;;) {
2100                 struct commit *p = *pp;
2101                 if (!revs->limited)
2102                         if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0)
2103                                 return rewrite_one_error;
2104                 if (p->parents && p->parents->next)
2105                         return rewrite_one_ok;
2106                 if (p->object.flags & UNINTERESTING)
2107                         return rewrite_one_ok;
2108                 if (!(p->object.flags & TREESAME))
2109                         return rewrite_one_ok;
2110                 if (!p->parents)
2111                         return rewrite_one_noparents;
2112                 *pp = p->parents->item;
2113         }
2114 }
2115
2116 static int rewrite_parents(struct rev_info *revs, struct commit *commit)
2117 {
2118         struct commit_list **pp = &commit->parents;
2119         while (*pp) {
2120                 struct commit_list *parent = *pp;
2121                 switch (rewrite_one(revs, &parent->item)) {
2122                 case rewrite_one_ok:
2123                         break;
2124                 case rewrite_one_noparents:
2125                         *pp = parent->next;
2126                         continue;
2127                 case rewrite_one_error:
2128                         return -1;
2129                 }
2130                 pp = &parent->next;
2131         }
2132         remove_duplicate_parents(commit);
2133         return 0;
2134 }
2135
2136 static int commit_match(struct commit *commit, struct rev_info *opt)
2137 {
2138         if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
2139                 return 1;
2140         return grep_buffer(&opt->grep_filter,
2141                            commit->buffer, strlen(commit->buffer));
2142 }
2143
2144 static inline int want_ancestry(struct rev_info *revs)
2145 {
2146         return (revs->rewrite_parents || revs->children.name);
2147 }
2148
2149 enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
2150 {
2151         if (commit->object.flags & SHOWN)
2152                 return commit_ignore;
2153         if (revs->unpacked && has_sha1_pack(commit->object.sha1))
2154                 return commit_ignore;
2155         if (revs->show_all)
2156                 return commit_show;
2157         if (commit->object.flags & UNINTERESTING)
2158                 return commit_ignore;
2159         if (revs->min_age != -1 && (commit->date > revs->min_age))
2160                 return commit_ignore;
2161         if (revs->min_parents || (revs->max_parents >= 0)) {
2162                 int n = 0;
2163                 struct commit_list *p;
2164                 for (p = commit->parents; p; p = p->next)
2165                         n++;
2166                 if ((n < revs->min_parents) ||
2167                     ((revs->max_parents >= 0) && (n > revs->max_parents)))
2168                         return commit_ignore;
2169         }
2170         if (!commit_match(commit, revs))
2171                 return commit_ignore;
2172         if (revs->prune && revs->dense) {
2173                 /* Commit without changes? */
2174                 if (commit->object.flags & TREESAME) {
2175                         /* drop merges unless we want parenthood */
2176                         if (!want_ancestry(revs))
2177                                 return commit_ignore;
2178                         /* non-merge - always ignore it */
2179                         if (!commit->parents || !commit->parents->next)
2180                                 return commit_ignore;
2181                 }
2182         }
2183         return commit_show;
2184 }
2185
2186 enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
2187 {
2188         enum commit_action action = get_commit_action(revs, commit);
2189
2190         if (action == commit_show &&
2191             !revs->show_all &&
2192             revs->prune && revs->dense && want_ancestry(revs)) {
2193                 if (rewrite_parents(revs, commit) < 0)
2194                         return commit_error;
2195         }
2196         return action;
2197 }
2198
2199 static struct commit *get_revision_1(struct rev_info *revs)
2200 {
2201         if (!revs->commits)
2202                 return NULL;
2203
2204         do {
2205                 struct commit_list *entry = revs->commits;
2206                 struct commit *commit = entry->item;
2207
2208                 revs->commits = entry->next;
2209                 free(entry);
2210
2211                 if (revs->reflog_info) {
2212                         fake_reflog_parent(revs->reflog_info, commit);
2213                         commit->object.flags &= ~(ADDED | SEEN | SHOWN);
2214                 }
2215
2216                 /*
2217                  * If we haven't done the list limiting, we need to look at
2218                  * the parents here. We also need to do the date-based limiting
2219                  * that we'd otherwise have done in limit_list().
2220                  */
2221                 if (!revs->limited) {
2222                         if (revs->max_age != -1 &&
2223                             (commit->date < revs->max_age))
2224                                 continue;
2225                         if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0)
2226                                 die("Failed to traverse parents of commit %s",
2227                                     sha1_to_hex(commit->object.sha1));
2228                 }
2229
2230                 switch (simplify_commit(revs, commit)) {
2231                 case commit_ignore:
2232                         continue;
2233                 case commit_error:
2234                         die("Failed to simplify parents of commit %s",
2235                             sha1_to_hex(commit->object.sha1));
2236                 default:
2237                         return commit;
2238                 }
2239         } while (revs->commits);
2240         return NULL;
2241 }
2242
2243 static void gc_boundary(struct object_array *array)
2244 {
2245         unsigned nr = array->nr;
2246         unsigned alloc = array->alloc;
2247         struct object_array_entry *objects = array->objects;
2248
2249         if (alloc <= nr) {
2250                 unsigned i, j;
2251                 for (i = j = 0; i < nr; i++) {
2252                         if (objects[i].item->flags & SHOWN)
2253                                 continue;
2254                         if (i != j)
2255                                 objects[j] = objects[i];
2256                         j++;
2257                 }
2258                 for (i = j; i < nr; i++)
2259                         objects[i].item = NULL;
2260                 array->nr = j;
2261         }
2262 }
2263
2264 static void create_boundary_commit_list(struct rev_info *revs)
2265 {
2266         unsigned i;
2267         struct commit *c;
2268         struct object_array *array = &revs->boundary_commits;
2269         struct object_array_entry *objects = array->objects;
2270
2271         /*
2272          * If revs->commits is non-NULL at this point, an error occurred in
2273          * get_revision_1().  Ignore the error and continue printing the
2274          * boundary commits anyway.  (This is what the code has always
2275          * done.)
2276          */
2277         if (revs->commits) {
2278                 free_commit_list(revs->commits);
2279                 revs->commits = NULL;
2280         }
2281
2282         /*
2283          * Put all of the actual boundary commits from revs->boundary_commits
2284          * into revs->commits
2285          */
2286         for (i = 0; i < array->nr; i++) {
2287                 c = (struct commit *)(objects[i].item);
2288                 if (!c)
2289                         continue;
2290                 if (!(c->object.flags & CHILD_SHOWN))
2291                         continue;
2292                 if (c->object.flags & (SHOWN | BOUNDARY))
2293                         continue;
2294                 c->object.flags |= BOUNDARY;
2295                 commit_list_insert(c, &revs->commits);
2296         }
2297
2298         /*
2299          * If revs->topo_order is set, sort the boundary commits
2300          * in topological order
2301          */
2302         sort_in_topological_order(&revs->commits, revs->lifo);
2303 }
2304
2305 static struct commit *get_revision_internal(struct rev_info *revs)
2306 {
2307         struct commit *c = NULL;
2308         struct commit_list *l;
2309
2310         if (revs->boundary == 2) {
2311                 /*
2312                  * All of the normal commits have already been returned,
2313                  * and we are now returning boundary commits.
2314                  * create_boundary_commit_list() has populated
2315                  * revs->commits with the remaining commits to return.
2316                  */
2317                 c = pop_commit(&revs->commits);
2318                 if (c)
2319                         c->object.flags |= SHOWN;
2320                 return c;
2321         }
2322
2323         /*
2324          * Now pick up what they want to give us
2325          */
2326         c = get_revision_1(revs);
2327         if (c) {
2328                 while (0 < revs->skip_count) {
2329                         revs->skip_count--;
2330                         c = get_revision_1(revs);
2331                         if (!c)
2332                                 break;
2333                 }
2334         }
2335
2336         /*
2337          * Check the max_count.
2338          */
2339         switch (revs->max_count) {
2340         case -1:
2341                 break;
2342         case 0:
2343                 c = NULL;
2344                 break;
2345         default:
2346                 revs->max_count--;
2347         }
2348
2349         if (c)
2350                 c->object.flags |= SHOWN;
2351
2352         if (!revs->boundary) {
2353                 return c;
2354         }
2355
2356         if (!c) {
2357                 /*
2358                  * get_revision_1() runs out the commits, and
2359                  * we are done computing the boundaries.
2360                  * switch to boundary commits output mode.
2361                  */
2362                 revs->boundary = 2;
2363
2364                 /*
2365                  * Update revs->commits to contain the list of
2366                  * boundary commits.
2367                  */
2368                 create_boundary_commit_list(revs);
2369
2370                 return get_revision_internal(revs);
2371         }
2372
2373         /*
2374          * boundary commits are the commits that are parents of the
2375          * ones we got from get_revision_1() but they themselves are
2376          * not returned from get_revision_1().  Before returning
2377          * 'c', we need to mark its parents that they could be boundaries.
2378          */
2379
2380         for (l = c->parents; l; l = l->next) {
2381                 struct object *p;
2382                 p = &(l->item->object);
2383                 if (p->flags & (CHILD_SHOWN | SHOWN))
2384                         continue;
2385                 p->flags |= CHILD_SHOWN;
2386                 gc_boundary(&revs->boundary_commits);
2387                 add_object_array(p, NULL, &revs->boundary_commits);
2388         }
2389
2390         return c;
2391 }
2392
2393 struct commit *get_revision(struct rev_info *revs)
2394 {
2395         struct commit *c;
2396         struct commit_list *reversed;
2397
2398         if (revs->reverse) {
2399                 reversed = NULL;
2400                 while ((c = get_revision_internal(revs))) {
2401                         commit_list_insert(c, &reversed);
2402                 }
2403                 revs->commits = reversed;
2404                 revs->reverse = 0;
2405                 revs->reverse_output_stage = 1;
2406         }
2407
2408         if (revs->reverse_output_stage)
2409                 return pop_commit(&revs->commits);
2410
2411         c = get_revision_internal(revs);
2412         if (c && revs->graph)
2413                 graph_update(revs->graph, c);
2414         return c;
2415 }
2416
2417 char *get_revision_mark(const struct rev_info *revs, const struct commit *commit)
2418 {
2419         if (commit->object.flags & BOUNDARY)
2420                 return "-";
2421         else if (commit->object.flags & UNINTERESTING)
2422                 return "^";
2423         else if (commit->object.flags & PATCHSAME)
2424                 return "=";
2425         else if (!revs || revs->left_right) {
2426                 if (commit->object.flags & SYMMETRIC_LEFT)
2427                         return "<";
2428                 else
2429                         return ">";
2430         } else if (revs->graph)
2431                 return "*";
2432         else if (revs->cherry_mark)
2433                 return "+";
2434         return "";
2435 }
2436
2437 void put_revision_mark(const struct rev_info *revs, const struct commit *commit)
2438 {
2439         char *mark = get_revision_mark(revs, commit);
2440         if (!strlen(mark))
2441                 return;
2442         fputs(mark, stdout);
2443         putchar(' ');
2444 }