revision.c

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