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