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