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
 364         if (commit->object.flags & ADDED)
 365                 return;
 366         commit->object.flags |= ADDED;
 367
 368         /*
 369          * If the commit is uninteresting, don't try to
 370          * prune parents - we want the maximal uninteresting
 371          * set.
 372          *
 373          * Normally we haven't parsed the parent
 374          * yet, so we won't have a parent of a parent
 375          * here. However, it may turn out that we've
 376          * reached this commit some other way (where it
 377          * wasn't uninteresting), in which case we need
 378          * to mark its parents recursively too..
 379          */
 380         if (commit->object.flags & UNINTERESTING) {
 381                 while (parent) {
 382                         struct commit *p = parent->item;
 383                         parent = parent->next;
 384                         parse_commit(p);
 385                         p->object.flags |= UNINTERESTING;
 386                         if (p->parents)
 387                                 mark_parents_uninteresting(p);
 388                         if (p->object.flags & SEEN)
 389                                 continue;
 390                         p->object.flags |= SEEN;
 391                         insert_by_date(p, list);
 392                 }
 393                 return;
 394         }
 395
 396         /*
 397          * Ok, the commit wasn't uninteresting. Try to
 398          * simplify the commit history and find the parent
 399          * that has no differences in the path set if one exists.
 400          */
 401         if (revs->prune_fn)
 402                 revs->prune_fn(revs, commit);
 403
 404         if (revs->no_walk)
 405                 return;
 406
 407         left_flag = (commit->object.flags & SYMMETRIC_LEFT);
 408         parent = commit->parents;
 409         while (parent) {
 410                 struct commit *p = parent->item;
 411
 412                 parent = parent->next;
 413
 414                 parse_commit(p);
 415                 p->object.flags |= left_flag;
 416                 if (p->object.flags & SEEN)
 417                         continue;
 418                 p->object.flags |= SEEN;
 419                 insert_by_date(p, list);
 420         }
 421 }
 422
 423 static void limit_list(struct rev_info *revs)
 424 {
 425         struct commit_list *list = revs->commits;
 426         struct commit_list *newlist = NULL;
 427         struct commit_list **p = &newlist;
 428
 429         while (list) {
 430                 struct commit_list *entry = list;
 431                 struct commit *commit = list->item;
 432                 struct object *obj = &commit->object;
 433
 434                 list = list->next;
 435                 free(entry);
 436
 437                 if (revs->max_age != -1 && (commit->date < revs->max_age))
 438                         obj->flags |= UNINTERESTING;
 439                 add_parents_to_list(revs, commit, &list);
 440                 if (obj->flags & UNINTERESTING) {
 441                         mark_parents_uninteresting(commit);
 442                         if (everybody_uninteresting(list))
 443                                 break;
 444                         continue;
 445                 }
 446                 if (revs->min_age != -1 && (commit->date > revs->min_age))
 447                         continue;
 448                 p = &commit_list_insert(commit, p)->next;
 449         }
 450         revs->commits = newlist;
 451 }
 452
 453 struct all_refs_cb {
 454         int all_flags;
 455         int warned_bad_reflog;
 456         struct rev_info *all_revs;
 457         const char *name_for_errormsg;
 458 };
 459
 460 static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 461 {
 462         struct all_refs_cb *cb = cb_data;
 463         struct object *object = get_reference(cb->all_revs, path, sha1,
 464                                               cb->all_flags);
 465         add_pending_object(cb->all_revs, object, path);
 466         return 0;
 467 }
 468
 469 static void handle_all(struct rev_info *revs, unsigned flags)
 470 {
 471         struct all_refs_cb cb;
 472         cb.all_revs = revs;
 473         cb.all_flags = flags;
 474         for_each_ref(handle_one_ref, &cb);
 475 }
 476
 477 static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
 478 {
 479         struct all_refs_cb *cb = cb_data;
 480         if (!is_null_sha1(sha1)) {
 481                 struct object *o = parse_object(sha1);
 482                 if (o) {
 483                         o->flags |= cb->all_flags;
 484                         add_pending_object(cb->all_revs, o, "");
 485                 }
 486                 else if (!cb->warned_bad_reflog) {
 487                         warn("reflog of '%s' references pruned commits",
 488                                 cb->name_for_errormsg);
 489                         cb->warned_bad_reflog = 1;
 490                 }
 491         }
 492 }
 493
 494 static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 495                 const char *email, unsigned long timestamp, int tz,
 496                 const char *message, void *cb_data)
 497 {
 498         handle_one_reflog_commit(osha1, cb_data);
 499         handle_one_reflog_commit(nsha1, cb_data);
 500         return 0;
 501 }
 502
 503 static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 504 {
 505         struct all_refs_cb *cb = cb_data;
 506         cb->warned_bad_reflog = 0;
 507         cb->name_for_errormsg = path;
 508         for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
 509         return 0;
 510 }
 511
 512 static void handle_reflog(struct rev_info *revs, unsigned flags)
 513 {
 514         struct all_refs_cb cb;
 515         cb.all_revs = revs;
 516         cb.all_flags = flags;
 517         for_each_reflog(handle_one_reflog, &cb);
 518 }
 519
 520 static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
 521 {
 522         unsigned char sha1[20];
 523         struct object *it;
 524         struct commit *commit;
 525         struct commit_list *parents;
 526
 527         if (*arg == '^') {
 528                 flags ^= UNINTERESTING;
 529                 arg++;
 530         }
 531         if (get_sha1(arg, sha1))
 532                 return 0;
 533         while (1) {
 534                 it = get_reference(revs, arg, sha1, 0);
 535                 if (it->type != OBJ_TAG)
 536                         break;
 537                 hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
 538         }
 539         if (it->type != OBJ_COMMIT)
 540                 return 0;
 541         commit = (struct commit *)it;
 542         for (parents = commit->parents; parents; parents = parents->next) {
 543                 it = &parents->item->object;
 544                 it->flags |= flags;
 545                 add_pending_object(revs, it, arg);
 546         }
 547         return 1;
 548 }
 549
 550 void init_revisions(struct rev_info *revs, const char *prefix)
 551 {
 552         memset(revs, 0, sizeof(*revs));
 553
 554         revs->abbrev = DEFAULT_ABBREV;
 555         revs->ignore_merges = 1;
 556         revs->simplify_history = 1;
 557         revs->pruning.recursive = 1;
 558         revs->pruning.quiet = 1;
 559         revs->pruning.add_remove = file_add_remove;
 560         revs->pruning.change = file_change;
 561         revs->lifo = 1;
 562         revs->dense = 1;
 563         revs->prefix = prefix;
 564         revs->max_age = -1;
 565         revs->min_age = -1;
 566         revs->skip_count = -1;
 567         revs->max_count = -1;
 568
 569         revs->prune_fn = NULL;
 570         revs->prune_data = NULL;
 571
 572         revs->topo_setter = topo_sort_default_setter;
 573         revs->topo_getter = topo_sort_default_getter;
 574
 575         revs->commit_format = CMIT_FMT_DEFAULT;
 576
 577         diff_setup(&revs->diffopt);
 578 }
 579
 580 static void add_pending_commit_list(struct rev_info *revs,
 581                                     struct commit_list *commit_list,
 582                                     unsigned int flags)
 583 {
 584         while (commit_list) {
 585                 struct object *object = &commit_list->item->object;
 586                 object->flags |= flags;
 587                 add_pending_object(revs, object, sha1_to_hex(object->sha1));
 588                 commit_list = commit_list->next;
 589         }
 590 }
 591
 592 static void prepare_show_merge(struct rev_info *revs)
 593 {
 594         struct commit_list *bases;
 595         struct commit *head, *other;
 596         unsigned char sha1[20];
 597         const char **prune = NULL;
 598         int i, prune_num = 1; /* counting terminating NULL */
 599
 600         if (get_sha1("HEAD", sha1) || !(head = lookup_commit(sha1)))
 601                 die("--merge without HEAD?");
 602         if (get_sha1("MERGE_HEAD", sha1) || !(other = lookup_commit(sha1)))
 603                 die("--merge without MERGE_HEAD?");
 604         add_pending_object(revs, &head->object, "HEAD");
 605         add_pending_object(revs, &other->object, "MERGE_HEAD");
 606         bases = get_merge_bases(head, other, 1);
 607         while (bases) {
 608                 struct commit *it = bases->item;
 609                 struct commit_list *n = bases->next;
 610                 free(bases);
 611                 bases = n;
 612                 it->object.flags |= UNINTERESTING;
 613                 add_pending_object(revs, &it->object, "(merge-base)");
 614         }
 615
 616         if (!active_nr)
 617                 read_cache();
 618         for (i = 0; i < active_nr; i++) {
 619                 struct cache_entry *ce = active_cache[i];
 620                 if (!ce_stage(ce))
 621                         continue;
 622                 if (ce_path_match(ce, revs->prune_data)) {
 623                         prune_num++;
 624                         prune = xrealloc(prune, sizeof(*prune) * prune_num);
 625                         prune[prune_num-2] = ce->name;
 626                         prune[prune_num-1] = NULL;
 627                 }
 628                 while ((i+1 < active_nr) &&
 629                        ce_same_name(ce, active_cache[i+1]))
 630                         i++;
 631         }
 632         revs->prune_data = prune;
 633 }
 634
 635 int handle_revision_arg(const char *arg, struct rev_info *revs,
 636                         int flags,
 637                         int cant_be_filename)
 638 {
 639         char *dotdot;
 640         struct object *object;
 641         unsigned char sha1[20];
 642         int local_flags;
 643
 644         dotdot = strstr(arg, "..");
 645         if (dotdot) {
 646                 unsigned char from_sha1[20];
 647                 const char *next = dotdot + 2;
 648                 const char *this = arg;
 649                 int symmetric = *next == '.';
 650                 unsigned int flags_exclude = flags ^ UNINTERESTING;
 651
 652                 *dotdot = 0;
 653                 next += symmetric;
 654
 655                 if (!*next)
 656                         next = "HEAD";
 657                 if (dotdot == arg)
 658                         this = "HEAD";
 659                 if (!get_sha1(this, from_sha1) &&
 660                     !get_sha1(next, sha1)) {
 661                         struct commit *a, *b;
 662                         struct commit_list *exclude;
 663
 664                         a = lookup_commit_reference(from_sha1);
 665                         b = lookup_commit_reference(sha1);
 666                         if (!a || !b) {
 667                                 die(symmetric ?
 668                                     "Invalid symmetric difference expression %s...%s" :
 669                                     "Invalid revision range %s..%s",
 670                                     arg, next);
 671                         }
 672
 673                         if (!cant_be_filename) {
 674                                 *dotdot = '.';
 675                                 verify_non_filename(revs->prefix, arg);
 676                         }
 677
 678                         if (symmetric) {
 679                                 exclude = get_merge_bases(a, b, 1);
 680                                 add_pending_commit_list(revs, exclude,
 681                                                         flags_exclude);
 682                                 free_commit_list(exclude);
 683                                 a->object.flags |= flags | SYMMETRIC_LEFT;
 684                         } else
 685                                 a->object.flags |= flags_exclude;
 686                         b->object.flags |= flags;
 687                         add_pending_object(revs, &a->object, this);
 688                         add_pending_object(revs, &b->object, next);
 689                         return 0;
 690                 }
 691                 *dotdot = '.';
 692         }
 693         dotdot = strstr(arg, "^@");
 694         if (dotdot && !dotdot[2]) {
 695                 *dotdot = 0;
 696                 if (add_parents_only(revs, arg, flags))
 697                         return 0;
 698                 *dotdot = '^';
 699         }
 700         dotdot = strstr(arg, "^!");
 701         if (dotdot && !dotdot[2]) {
 702                 *dotdot = 0;
 703                 if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
 704                         *dotdot = '^';
 705         }
 706
 707         local_flags = 0;
 708         if (*arg == '^') {
 709                 local_flags = UNINTERESTING;
 710                 arg++;
 711         }
 712         if (get_sha1(arg, sha1))
 713                 return -1;
 714         if (!cant_be_filename)
 715                 verify_non_filename(revs->prefix, arg);
 716         object = get_reference(revs, arg, sha1, flags ^ local_flags);
 717         add_pending_object(revs, object, arg);
 718         return 0;
 719 }
 720
 721 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
 722 {
 723         if (!revs->grep_filter) {
 724                 struct grep_opt *opt = xcalloc(1, sizeof(*opt));
 725                 opt->status_only = 1;
 726                 opt->pattern_tail = &(opt->pattern_list);
 727                 opt->regflags = REG_NEWLINE;
 728                 revs->grep_filter = opt;
 729         }
 730         append_grep_pattern(revs->grep_filter, ptn,
 731                             "command line", 0, what);
 732 }
 733
 734 static void add_header_grep(struct rev_info *revs, const char *field, const char *pattern)
 735 {
 736         char *pat;
 737         const char *prefix;
 738         int patlen, fldlen;
 739
 740         fldlen = strlen(field);
 741         patlen = strlen(pattern);
 742         pat = xmalloc(patlen + fldlen + 10);
 743         prefix = ".*";
 744         if (*pattern == '^') {
 745                 prefix = "";
 746                 pattern++;
 747         }
 748         sprintf(pat, "^%s %s%s", field, prefix, pattern);
 749         add_grep(revs, pat, GREP_PATTERN_HEAD);
 750 }
 751
 752 static void add_message_grep(struct rev_info *revs, const char *pattern)
 753 {
 754         add_grep(revs, pattern, GREP_PATTERN_BODY);
 755 }
 756
 757 static void add_ignore_packed(struct rev_info *revs, const char *name)
 758 {
 759         int num = ++revs->num_ignore_packed;
 760
 761         revs->ignore_packed = xrealloc(revs->ignore_packed,
 762                                        sizeof(const char **) * (num + 1));
 763         revs->ignore_packed[num-1] = name;
 764         revs->ignore_packed[num] = NULL;
 765 }
 766
 767 /*
 768  * Parse revision information, filling in the "rev_info" structure,
 769  * and removing the used arguments from the argument list.
 770  *
 771  * Returns the number of arguments left that weren't recognized
 772  * (which are also moved to the head of the argument list)
 773  */
 774 int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
 775 {
 776         int i, flags, seen_dashdash, show_merge;
 777         const char **unrecognized = argv + 1;
 778         int left = 1;
 779         int all_match = 0;
 780
 781         /* First, search for "--" */
 782         seen_dashdash = 0;
 783         for (i = 1; i < argc; i++) {
 784                 const char *arg = argv[i];
 785                 if (strcmp(arg, "--"))
 786                         continue;
 787                 argv[i] = NULL;
 788                 argc = i;
 789                 revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
 790                 seen_dashdash = 1;
 791                 break;
 792         }
 793
 794         flags = show_merge = 0;
 795         for (i = 1; i < argc; i++) {
 796                 const char *arg = argv[i];
 797                 if (*arg == '-') {
 798                         int opts;
 799                         if (!prefixcmp(arg, "--max-count=")) {
 800                                 revs->max_count = atoi(arg + 12);
 801                                 continue;
 802                         }
 803                         if (!prefixcmp(arg, "--skip=")) {
 804                                 revs->skip_count = atoi(arg + 7);
 805                                 continue;
 806                         }
 807                         /* accept -<digit>, like traditional "head" */
 808                         if ((*arg == '-') && isdigit(arg[1])) {
 809                                 revs->max_count = atoi(arg + 1);
 810                                 continue;
 811                         }
 812                         if (!strcmp(arg, "-n")) {
 813                                 if (argc <= i + 1)
 814                                         die("-n requires an argument");
 815                                 revs->max_count = atoi(argv[++i]);
 816                                 continue;
 817                         }
 818                         if (!prefixcmp(arg, "-n")) {
 819                                 revs->max_count = atoi(arg + 2);
 820                                 continue;
 821                         }
 822                         if (!prefixcmp(arg, "--max-age=")) {
 823                                 revs->max_age = atoi(arg + 10);
 824                                 continue;
 825                         }
 826                         if (!prefixcmp(arg, "--since=")) {
 827                                 revs->max_age = approxidate(arg + 8);
 828                                 continue;
 829                         }
 830                         if (!prefixcmp(arg, "--after=")) {
 831                                 revs->max_age = approxidate(arg + 8);
 832                                 continue;
 833                         }
 834                         if (!prefixcmp(arg, "--min-age=")) {
 835                                 revs->min_age = atoi(arg + 10);
 836                                 continue;
 837                         }
 838                         if (!prefixcmp(arg, "--before=")) {
 839                                 revs->min_age = approxidate(arg + 9);
 840                                 continue;
 841                         }
 842                         if (!prefixcmp(arg, "--until=")) {
 843                                 revs->min_age = approxidate(arg + 8);
 844                                 continue;
 845                         }
 846                         if (!strcmp(arg, "--all")) {
 847                                 handle_all(revs, flags);
 848                                 continue;
 849                         }
 850                         if (!strcmp(arg, "--reflog")) {
 851                                 handle_reflog(revs, flags);
 852                                 continue;
 853                         }
 854                         if (!strcmp(arg, "-g") ||
 855                                         !strcmp(arg, "--walk-reflogs")) {
 856                                 init_reflog_walk(&revs->reflog_info);
 857                                 continue;
 858                         }
 859                         if (!strcmp(arg, "--not")) {
 860                                 flags ^= UNINTERESTING;
 861                                 continue;
 862                         }
 863                         if (!strcmp(arg, "--default")) {
 864                                 if (++i >= argc)
 865                                         die("bad --default argument");
 866                                 def = argv[i];
 867                                 continue;
 868                         }
 869                         if (!strcmp(arg, "--merge")) {
 870                                 show_merge = 1;
 871                                 continue;
 872                         }
 873                         if (!strcmp(arg, "--topo-order")) {
 874                                 revs->topo_order = 1;
 875                                 continue;
 876                         }
 877                         if (!strcmp(arg, "--date-order")) {
 878                                 revs->lifo = 0;
 879                                 revs->topo_order = 1;
 880                                 continue;
 881                         }
 882                         if (!strcmp(arg, "--parents")) {
 883                                 revs->parents = 1;
 884                                 continue;
 885                         }
 886                         if (!strcmp(arg, "--dense")) {
 887                                 revs->dense = 1;
 888                                 continue;
 889                         }
 890                         if (!strcmp(arg, "--sparse")) {
 891                                 revs->dense = 0;
 892                                 continue;
 893                         }
 894                         if (!strcmp(arg, "--remove-empty")) {
 895                                 revs->remove_empty_trees = 1;
 896                                 continue;
 897                         }
 898                         if (!strcmp(arg, "--no-merges")) {
 899                                 revs->no_merges = 1;
 900                                 continue;
 901                         }
 902                         if (!strcmp(arg, "--boundary")) {
 903                                 revs->boundary = 1;
 904                                 continue;
 905                         }
 906                         if (!strcmp(arg, "--left-right")) {
 907                                 revs->left_right = 1;
 908                                 continue;
 909                         }
 910                         if (!strcmp(arg, "--objects")) {
 911                                 revs->tag_objects = 1;
 912                                 revs->tree_objects = 1;
 913                                 revs->blob_objects = 1;
 914                                 continue;
 915                         }
 916                         if (!strcmp(arg, "--objects-edge")) {
 917                                 revs->tag_objects = 1;
 918                                 revs->tree_objects = 1;
 919                                 revs->blob_objects = 1;
 920                                 revs->edge_hint = 1;
 921                                 continue;
 922                         }
 923                         if (!strcmp(arg, "--unpacked")) {
 924                                 revs->unpacked = 1;
 925                                 free(revs->ignore_packed);
 926                                 revs->ignore_packed = NULL;
 927                                 revs->num_ignore_packed = 0;
 928                                 continue;
 929                         }
 930                         if (!prefixcmp(arg, "--unpacked=")) {
 931                                 revs->unpacked = 1;
 932                                 add_ignore_packed(revs, arg+11);
 933                                 continue;
 934                         }
 935                         if (!strcmp(arg, "-r")) {
 936                                 revs->diff = 1;
 937                                 revs->diffopt.recursive = 1;
 938                                 continue;
 939                         }
 940                         if (!strcmp(arg, "-t")) {
 941                                 revs->diff = 1;
 942                                 revs->diffopt.recursive = 1;
 943                                 revs->diffopt.tree_in_recursive = 1;
 944                                 continue;
 945                         }
 946                         if (!strcmp(arg, "-m")) {
 947                                 revs->ignore_merges = 0;
 948                                 continue;
 949                         }
 950                         if (!strcmp(arg, "-c")) {
 951                                 revs->diff = 1;
 952                                 revs->dense_combined_merges = 0;
 953                                 revs->combine_merges = 1;
 954                                 continue;
 955                         }
 956                         if (!strcmp(arg, "--cc")) {
 957                                 revs->diff = 1;
 958                                 revs->dense_combined_merges = 1;
 959                                 revs->combine_merges = 1;
 960                                 continue;
 961                         }
 962                         if (!strcmp(arg, "-v")) {
 963                                 revs->verbose_header = 1;
 964                                 continue;
 965                         }
 966                         if (!prefixcmp(arg, "--pretty")) {
 967                                 revs->verbose_header = 1;
 968                                 revs->commit_format = get_commit_format(arg+8);
 969                                 continue;
 970                         }
 971                         if (!strcmp(arg, "--root")) {
 972                                 revs->show_root_diff = 1;
 973                                 continue;
 974                         }
 975                         if (!strcmp(arg, "--no-commit-id")) {
 976                                 revs->no_commit_id = 1;
 977                                 continue;
 978                         }
 979                         if (!strcmp(arg, "--always")) {
 980                                 revs->always_show_header = 1;
 981                                 continue;
 982                         }
 983                         if (!strcmp(arg, "--no-abbrev")) {
 984                                 revs->abbrev = 0;
 985                                 continue;
 986                         }
 987                         if (!strcmp(arg, "--abbrev")) {
 988                                 revs->abbrev = DEFAULT_ABBREV;
 989                                 continue;
 990                         }
 991                         if (!prefixcmp(arg, "--abbrev=")) {
 992                                 revs->abbrev = strtoul(arg + 9, NULL, 10);
 993                                 if (revs->abbrev < MINIMUM_ABBREV)
 994                                         revs->abbrev = MINIMUM_ABBREV;
 995                                 else if (revs->abbrev > 40)
 996                                         revs->abbrev = 40;
 997                                 continue;
 998                         }
 999                         if (!strcmp(arg, "--abbrev-commit")) {
1000                                 revs->abbrev_commit = 1;
1001                                 continue;
1002                         }
1003                         if (!strcmp(arg, "--full-diff")) {
1004                                 revs->diff = 1;
1005                                 revs->full_diff = 1;
1006                                 continue;
1007                         }
1008                         if (!strcmp(arg, "--full-history")) {
1009                                 revs->simplify_history = 0;
1010                                 continue;
1011                         }
1012                         if (!strcmp(arg, "--relative-date")) {
1013                                 revs->relative_date = 1;
1014                                 continue;
1015                         }
1016
1017                         /*
1018                          * Grepping the commit log
1019                          */
1020                         if (!prefixcmp(arg, "--author=")) {
1021                                 add_header_grep(revs, "author", arg+9);
1022                                 continue;
1023                         }
1024                         if (!prefixcmp(arg, "--committer=")) {
1025                                 add_header_grep(revs, "committer", arg+12);
1026                                 continue;
1027                         }
1028                         if (!prefixcmp(arg, "--grep=")) {
1029                                 add_message_grep(revs, arg+7);
1030                                 continue;
1031                         }
1032                         if (!strcmp(arg, "--all-match")) {
1033                                 all_match = 1;
1034                                 continue;
1035                         }
1036                         if (!prefixcmp(arg, "--encoding=")) {
1037                                 arg += 11;
1038                                 if (strcmp(arg, "none"))
1039                                         git_log_output_encoding = xstrdup(arg);
1040                                 else
1041                                         git_log_output_encoding = "";
1042                                 continue;
1043                         }
1044                         if (!strcmp(arg, "--reverse")) {
1045                                 revs->reverse ^= 1;
1046                                 continue;
1047                         }
1048
1049                         opts = diff_opt_parse(&revs->diffopt, argv+i, argc-i);
1050                         if (opts > 0) {
1051                                 revs->diff = 1;
1052                                 i += opts - 1;
1053                                 continue;
1054                         }
1055                         *unrecognized++ = arg;
1056                         left++;
1057                         continue;
1058                 }
1059
1060                 if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
1061                         int j;
1062                         if (seen_dashdash || *arg == '^')
1063                                 die("bad revision '%s'", arg);
1064
1065                         /* If we didn't have a "--":
1066                          * (1) all filenames must exist;
1067                          * (2) all rev-args must not be interpretable
1068                          *     as a valid filename.
1069                          * but the latter we have checked in the main loop.
1070                          */
1071                         for (j = i; j < argc; j++)
1072                                 verify_filename(revs->prefix, argv[j]);
1073
1074                         revs->prune_data = get_pathspec(revs->prefix,
1075                                                         argv + i);
1076                         break;
1077                 }
1078         }
1079
1080         if (show_merge)
1081                 prepare_show_merge(revs);
1082         if (def && !revs->pending.nr) {
1083                 unsigned char sha1[20];
1084                 struct object *object;
1085                 if (get_sha1(def, sha1))
1086                         die("bad default revision '%s'", def);
1087                 object = get_reference(revs, def, sha1, 0);
1088                 add_pending_object(revs, object, def);
1089         }
1090
1091         if (revs->topo_order)
1092                 revs->limited = 1;
1093
1094         if (revs->prune_data) {
1095                 diff_tree_setup_paths(revs->prune_data, &revs->pruning);
1096                 revs->prune_fn = try_to_simplify_commit;
1097                 if (!revs->full_diff)
1098                         diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
1099         }
1100         if (revs->combine_merges) {
1101                 revs->ignore_merges = 0;
1102                 if (revs->dense_combined_merges && !revs->diffopt.output_format)
1103                         revs->diffopt.output_format = DIFF_FORMAT_PATCH;
1104         }
1105         revs->diffopt.abbrev = revs->abbrev;
1106         if (diff_setup_done(&revs->diffopt) < 0)
1107                 die("diff_setup_done failed");
1108
1109         if (revs->grep_filter) {
1110                 revs->grep_filter->all_match = all_match;
1111                 compile_grep_patterns(revs->grep_filter);
1112         }
1113
1114         return left;
1115 }
1116
1117 void prepare_revision_walk(struct rev_info *revs)
1118 {
1119         int nr = revs->pending.nr;
1120         struct object_array_entry *e, *list;
1121
1122         e = list = revs->pending.objects;
1123         revs->pending.nr = 0;
1124         revs->pending.alloc = 0;
1125         revs->pending.objects = NULL;
1126         while (--nr >= 0) {
1127                 struct commit *commit = handle_commit(revs, e->item, e->name);
1128                 if (commit) {
1129                         if (!(commit->object.flags & SEEN)) {
1130                                 commit->object.flags |= SEEN;
1131                                 insert_by_date(commit, &revs->commits);
1132                         }
1133                 }
1134                 e++;
1135         }
1136         free(list);
1137
1138         if (revs->no_walk)
1139                 return;
1140         if (revs->limited)
1141                 limit_list(revs);
1142         if (revs->topo_order)
1143                 sort_in_topological_order_fn(&revs->commits, revs->lifo,
1144                                              revs->topo_setter,
1145                                              revs->topo_getter);
1146 }
1147
1148 static int rewrite_one(struct rev_info *revs, struct commit **pp)
1149 {
1150         for (;;) {
1151                 struct commit *p = *pp;
1152                 if (!revs->limited)
1153                         add_parents_to_list(revs, p, &revs->commits);
1154                 if (p->parents && p->parents->next)
1155                         return 0;
1156                 if (p->object.flags & (TREECHANGE | UNINTERESTING))
1157                         return 0;
1158                 if (!p->parents)
1159                         return -1;
1160                 *pp = p->parents->item;
1161         }
1162 }
1163
1164 static void rewrite_parents(struct rev_info *revs, struct commit *commit)
1165 {
1166         struct commit_list **pp = &commit->parents;
1167         while (*pp) {
1168                 struct commit_list *parent = *pp;
1169                 if (rewrite_one(revs, &parent->item) < 0) {
1170                         *pp = parent->next;
1171                         continue;
1172                 }
1173                 pp = &parent->next;
1174         }
1175 }
1176
1177 static int commit_match(struct commit *commit, struct rev_info *opt)
1178 {
1179         if (!opt->grep_filter)
1180                 return 1;
1181         return grep_buffer(opt->grep_filter,
1182                            NULL, /* we say nothing, not even filename */
1183                            commit->buffer, strlen(commit->buffer));
1184 }
1185
1186 static struct commit *get_revision_1(struct rev_info *revs)
1187 {
1188         if (!revs->commits)
1189                 return NULL;
1190
1191         do {
1192                 struct commit_list *entry = revs->commits;
1193                 struct commit *commit = entry->item;
1194
1195                 revs->commits = entry->next;
1196                 free(entry);
1197
1198                 if (revs->reflog_info)
1199                         fake_reflog_parent(revs->reflog_info, commit);
1200
1201                 /*
1202                  * If we haven't done the list limiting, we need to look at
1203                  * the parents here. We also need to do the date-based limiting
1204                  * that we'd otherwise have done in limit_list().
1205                  */
1206                 if (!revs->limited) {
1207                         if (revs->max_age != -1 &&
1208                             (commit->date < revs->max_age))
1209                                 continue;
1210                         add_parents_to_list(revs, commit, &revs->commits);
1211                 }
1212                 if (commit->object.flags & SHOWN)
1213                         continue;
1214
1215                 if (revs->unpacked && has_sha1_pack(commit->object.sha1,
1216                                                     revs->ignore_packed))
1217                     continue;
1218
1219                 if (commit->object.flags & UNINTERESTING)
1220                         continue;
1221                 if (revs->min_age != -1 && (commit->date > revs->min_age))
1222                         continue;
1223                 if (revs->no_merges &&
1224                     commit->parents && commit->parents->next)
1225                         continue;
1226                 if (!commit_match(commit, revs))
1227                         continue;
1228                 if (revs->prune_fn && revs->dense) {
1229                         /* Commit without changes? */
1230                         if (!(commit->object.flags & TREECHANGE)) {
1231                                 /* drop merges unless we want parenthood */
1232                                 if (!revs->parents)
1233                                         continue;
1234                                 /* non-merge - always ignore it */
1235                                 if (!commit->parents || !commit->parents->next)
1236                                         continue;
1237                         }
1238                         if (revs->parents)
1239                                 rewrite_parents(revs, commit);
1240                 }
1241                 return commit;
1242         } while (revs->commits);
1243         return NULL;
1244 }
1245
1246 static void gc_boundary(struct object_array *array)
1247 {
1248         unsigned nr = array->nr;
1249         unsigned alloc = array->alloc;
1250         struct object_array_entry *objects = array->objects;
1251
1252         if (alloc <= nr) {
1253                 unsigned i, j;
1254                 for (i = j = 0; i < nr; i++) {
1255                         if (objects[i].item->flags & SHOWN)
1256                                 continue;
1257                         if (i != j)
1258                                 objects[j] = objects[i];
1259                         j++;
1260                 }
1261                 for (i = j; i < nr; i++)
1262                         objects[i].item = NULL;
1263                 array->nr = j;
1264         }
1265 }
1266
1267 struct commit *get_revision(struct rev_info *revs)
1268 {
1269         struct commit *c = NULL;
1270         struct commit_list *l;
1271
1272         if (revs->boundary == 2) {
1273                 unsigned i;
1274                 struct object_array *array = &revs->boundary_commits;
1275                 struct object_array_entry *objects = array->objects;
1276                 for (i = 0; i < array->nr; i++) {
1277                         c = (struct commit *)(objects[i].item);
1278                         if (!c)
1279                                 continue;
1280                         if (!(c->object.flags & CHILD_SHOWN))
1281                                 continue;
1282                         if (!(c->object.flags & SHOWN))
1283                                 break;
1284                 }
1285                 if (array->nr <= i)
1286                         return NULL;
1287
1288                 c->object.flags |= SHOWN | BOUNDARY;
1289                 return c;
1290         }
1291
1292         if (revs->reverse) {
1293                 int limit = -1;
1294
1295                 if (0 <= revs->max_count) {
1296                         limit = revs->max_count;
1297                         if (0 < revs->skip_count)
1298                                 limit += revs->skip_count;
1299                 }
1300                 l = NULL;
1301                 while ((c = get_revision_1(revs))) {
1302                         commit_list_insert(c, &l);
1303                         if ((0 < limit) && !--limit)
1304                                 break;
1305                 }
1306                 revs->commits = l;
1307                 revs->reverse = 0;
1308                 revs->max_count = -1;
1309                 c = NULL;
1310         }
1311
1312         /*
1313          * Now pick up what they want to give us
1314          */
1315         c = get_revision_1(revs);
1316         if (c) {
1317                 while (0 < revs->skip_count) {
1318                         revs->skip_count--;
1319                         c = get_revision_1(revs);
1320                         if (!c)
1321                                 break;
1322                 }
1323         }
1324
1325         /*
1326          * Check the max_count.
1327          */
1328         switch (revs->max_count) {
1329         case -1:
1330                 break;
1331         case 0:
1332                 c = NULL;
1333                 break;
1334         default:
1335                 revs->max_count--;
1336         }
1337
1338         if (c)
1339                 c->object.flags |= SHOWN;
1340
1341         if (!revs->boundary) {
1342                 return c;
1343         }
1344
1345         if (!c) {
1346                 /*
1347                  * get_revision_1() runs out the commits, and
1348                  * we are done computing the boundaries.
1349                  * switch to boundary commits output mode.
1350                  */
1351                 revs->boundary = 2;
1352                 return get_revision(revs);
1353         }
1354
1355         /*
1356          * boundary commits are the commits that are parents of the
1357          * ones we got from get_revision_1() but they themselves are
1358          * not returned from get_revision_1().  Before returning
1359          * 'c', we need to mark its parents that they could be boundaries.
1360          */
1361
1362         for (l = c->parents; l; l = l->next) {
1363                 struct object *p;
1364                 p = &(l->item->object);
1365                 if (p->flags & (CHILD_SHOWN | SHOWN))
1366                         continue;
1367                 p->flags |= CHILD_SHOWN;
1368                 gc_boundary(&revs->boundary_commits);
1369                 add_object_array(p, NULL, &revs->boundary_commits);
1370         }
1371
1372         return c;
1373 }