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         revs->subject_prefix = "PATCH";
 571
 572         revs->prune_fn = NULL;
 573         revs->prune_data = NULL;
 574
 575         revs->topo_setter = topo_sort_default_setter;
 576         revs->topo_getter = topo_sort_default_getter;
 577
 578         revs->commit_format = CMIT_FMT_DEFAULT;
 579
 580         diff_setup(&revs->diffopt);
 581 }
 582
 583 static void add_pending_commit_list(struct rev_info *revs,
 584                                     struct commit_list *commit_list,
 585                                     unsigned int flags)
 586 {
 587         while (commit_list) {
 588                 struct object *object = &commit_list->item->object;
 589                 object->flags |= flags;
 590                 add_pending_object(revs, object, sha1_to_hex(object->sha1));
 591                 commit_list = commit_list->next;
 592         }
 593 }
 594
 595 static void prepare_show_merge(struct rev_info *revs)
 596 {
 597         struct commit_list *bases;
 598         struct commit *head, *other;
 599         unsigned char sha1[20];
 600         const char **prune = NULL;
 601         int i, prune_num = 1; /* counting terminating NULL */
 602
 603         if (get_sha1("HEAD", sha1) || !(head = lookup_commit(sha1)))
 604                 die("--merge without HEAD?");
 605         if (get_sha1("MERGE_HEAD", sha1) || !(other = lookup_commit(sha1)))
 606                 die("--merge without MERGE_HEAD?");
 607         add_pending_object(revs, &head->object, "HEAD");
 608         add_pending_object(revs, &other->object, "MERGE_HEAD");
 609         bases = get_merge_bases(head, other, 1);
 610         while (bases) {
 611                 struct commit *it = bases->item;
 612                 struct commit_list *n = bases->next;
 613                 free(bases);
 614                 bases = n;
 615                 it->object.flags |= UNINTERESTING;
 616                 add_pending_object(revs, &it->object, "(merge-base)");
 617         }
 618
 619         if (!active_nr)
 620                 read_cache();
 621         for (i = 0; i < active_nr; i++) {
 622                 struct cache_entry *ce = active_cache[i];
 623                 if (!ce_stage(ce))
 624                         continue;
 625                 if (ce_path_match(ce, revs->prune_data)) {
 626                         prune_num++;
 627                         prune = xrealloc(prune, sizeof(*prune) * prune_num);
 628                         prune[prune_num-2] = ce->name;
 629                         prune[prune_num-1] = NULL;
 630                 }
 631                 while ((i+1 < active_nr) &&
 632                        ce_same_name(ce, active_cache[i+1]))
 633                         i++;
 634         }
 635         revs->prune_data = prune;
 636 }
 637
 638 int handle_revision_arg(const char *arg, struct rev_info *revs,
 639                         int flags,
 640                         int cant_be_filename)
 641 {
 642         char *dotdot;
 643         struct object *object;
 644         unsigned char sha1[20];
 645         int local_flags;
 646
 647         dotdot = strstr(arg, "..");
 648         if (dotdot) {
 649                 unsigned char from_sha1[20];
 650                 const char *next = dotdot + 2;
 651                 const char *this = arg;
 652                 int symmetric = *next == '.';
 653                 unsigned int flags_exclude = flags ^ UNINTERESTING;
 654
 655                 *dotdot = 0;
 656                 next += symmetric;
 657
 658                 if (!*next)
 659                         next = "HEAD";
 660                 if (dotdot == arg)
 661                         this = "HEAD";
 662                 if (!get_sha1(this, from_sha1) &&
 663                     !get_sha1(next, sha1)) {
 664                         struct commit *a, *b;
 665                         struct commit_list *exclude;
 666
 667                         a = lookup_commit_reference(from_sha1);
 668                         b = lookup_commit_reference(sha1);
 669                         if (!a || !b) {
 670                                 die(symmetric ?
 671                                     "Invalid symmetric difference expression %s...%s" :
 672                                     "Invalid revision range %s..%s",
 673                                     arg, next);
 674                         }
 675
 676                         if (!cant_be_filename) {
 677                                 *dotdot = '.';
 678                                 verify_non_filename(revs->prefix, arg);
 679                         }
 680
 681                         if (symmetric) {
 682                                 exclude = get_merge_bases(a, b, 1);
 683                                 add_pending_commit_list(revs, exclude,
 684                                                         flags_exclude);
 685                                 free_commit_list(exclude);
 686                                 a->object.flags |= flags | SYMMETRIC_LEFT;
 687                         } else
 688                                 a->object.flags |= flags_exclude;
 689                         b->object.flags |= flags;
 690                         add_pending_object(revs, &a->object, this);
 691                         add_pending_object(revs, &b->object, next);
 692                         return 0;
 693                 }
 694                 *dotdot = '.';
 695         }
 696         dotdot = strstr(arg, "^@");
 697         if (dotdot && !dotdot[2]) {
 698                 *dotdot = 0;
 699                 if (add_parents_only(revs, arg, flags))
 700                         return 0;
 701                 *dotdot = '^';
 702         }
 703         dotdot = strstr(arg, "^!");
 704         if (dotdot && !dotdot[2]) {
 705                 *dotdot = 0;
 706                 if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
 707                         *dotdot = '^';
 708         }
 709
 710         local_flags = 0;
 711         if (*arg == '^') {
 712                 local_flags = UNINTERESTING;
 713                 arg++;
 714         }
 715         if (get_sha1(arg, sha1))
 716                 return -1;
 717         if (!cant_be_filename)
 718                 verify_non_filename(revs->prefix, arg);
 719         object = get_reference(revs, arg, sha1, flags ^ local_flags);
 720         add_pending_object(revs, object, arg);
 721         return 0;
 722 }
 723
 724 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
 725 {
 726         if (!revs->grep_filter) {
 727                 struct grep_opt *opt = xcalloc(1, sizeof(*opt));
 728                 opt->status_only = 1;
 729                 opt->pattern_tail = &(opt->pattern_list);
 730                 opt->regflags = REG_NEWLINE;
 731                 revs->grep_filter = opt;
 732         }
 733         append_grep_pattern(revs->grep_filter, ptn,
 734                             "command line", 0, what);
 735 }
 736
 737 static void add_header_grep(struct rev_info *revs, const char *field, const char *pattern)
 738 {
 739         char *pat;
 740         const char *prefix;
 741         int patlen, fldlen;
 742
 743         fldlen = strlen(field);
 744         patlen = strlen(pattern);
 745         pat = xmalloc(patlen + fldlen + 10);
 746         prefix = ".*";
 747         if (*pattern == '^') {
 748                 prefix = "";
 749                 pattern++;
 750         }
 751         sprintf(pat, "^%s %s%s", field, prefix, pattern);
 752         add_grep(revs, pat, GREP_PATTERN_HEAD);
 753 }
 754
 755 static void add_message_grep(struct rev_info *revs, const char *pattern)
 756 {
 757         add_grep(revs, pattern, GREP_PATTERN_BODY);
 758 }
 759
 760 static void add_ignore_packed(struct rev_info *revs, const char *name)
 761 {
 762         int num = ++revs->num_ignore_packed;
 763
 764         revs->ignore_packed = xrealloc(revs->ignore_packed,
 765                                        sizeof(const char **) * (num + 1));
 766         revs->ignore_packed[num-1] = name;
 767         revs->ignore_packed[num] = NULL;
 768 }
 769
 770 /*
 771  * Parse revision information, filling in the "rev_info" structure,
 772  * and removing the used arguments from the argument list.
 773  *
 774  * Returns the number of arguments left that weren't recognized
 775  * (which are also moved to the head of the argument list)
 776  */
 777 int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
 778 {
 779         int i, flags, seen_dashdash, show_merge;
 780         const char **unrecognized = argv + 1;
 781         int left = 1;
 782         int all_match = 0;
 783
 784         /* First, search for "--" */
 785         seen_dashdash = 0;
 786         for (i = 1; i < argc; i++) {
 787                 const char *arg = argv[i];
 788                 if (strcmp(arg, "--"))
 789                         continue;
 790                 argv[i] = NULL;
 791                 argc = i;
 792                 revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
 793                 seen_dashdash = 1;
 794                 break;
 795         }
 796
 797         flags = show_merge = 0;
 798         for (i = 1; i < argc; i++) {
 799                 const char *arg = argv[i];
 800                 if (*arg == '-') {
 801                         int opts;
 802                         if (!prefixcmp(arg, "--max-count=")) {
 803                                 revs->max_count = atoi(arg + 12);
 804                                 continue;
 805                         }
 806                         if (!prefixcmp(arg, "--skip=")) {
 807                                 revs->skip_count = atoi(arg + 7);
 808                                 continue;
 809                         }
 810                         /* accept -<digit>, like traditional "head" */
 811                         if ((*arg == '-') && isdigit(arg[1])) {
 812                                 revs->max_count = atoi(arg + 1);
 813                                 continue;
 814                         }
 815                         if (!strcmp(arg, "-n")) {
 816                                 if (argc <= i + 1)
 817                                         die("-n requires an argument");
 818                                 revs->max_count = atoi(argv[++i]);
 819                                 continue;
 820                         }
 821                         if (!prefixcmp(arg, "-n")) {
 822                                 revs->max_count = atoi(arg + 2);
 823                                 continue;
 824                         }
 825                         if (!prefixcmp(arg, "--max-age=")) {
 826                                 revs->max_age = atoi(arg + 10);
 827                                 continue;
 828                         }
 829                         if (!prefixcmp(arg, "--since=")) {
 830                                 revs->max_age = approxidate(arg + 8);
 831                                 continue;
 832                         }
 833                         if (!prefixcmp(arg, "--after=")) {
 834                                 revs->max_age = approxidate(arg + 8);
 835                                 continue;
 836                         }
 837                         if (!prefixcmp(arg, "--min-age=")) {
 838                                 revs->min_age = atoi(arg + 10);
 839                                 continue;
 840                         }
 841                         if (!prefixcmp(arg, "--before=")) {
 842                                 revs->min_age = approxidate(arg + 9);
 843                                 continue;
 844                         }
 845                         if (!prefixcmp(arg, "--until=")) {
 846                                 revs->min_age = approxidate(arg + 8);
 847                                 continue;
 848                         }
 849                         if (!strcmp(arg, "--all")) {
 850                                 handle_all(revs, flags);
 851                                 continue;
 852                         }
 853                         if (!strcmp(arg, "--first-parent")) {
 854                                 revs->first_parent_only = 1;
 855                                 continue;
 856                         }
 857                         if (!strcmp(arg, "--reflog")) {
 858                                 handle_reflog(revs, flags);
 859                                 continue;
 860                         }
 861                         if (!strcmp(arg, "-g") ||
 862                                         !strcmp(arg, "--walk-reflogs")) {
 863                                 init_reflog_walk(&revs->reflog_info);
 864                                 continue;
 865                         }
 866                         if (!strcmp(arg, "--not")) {
 867                                 flags ^= UNINTERESTING;
 868                                 continue;
 869                         }
 870                         if (!strcmp(arg, "--default")) {
 871                                 if (++i >= argc)
 872                                         die("bad --default argument");
 873                                 def = argv[i];
 874                                 continue;
 875                         }
 876                         if (!strcmp(arg, "--merge")) {
 877                                 show_merge = 1;
 878                                 continue;
 879                         }
 880                         if (!strcmp(arg, "--topo-order")) {
 881                                 revs->topo_order = 1;
 882                                 continue;
 883                         }
 884                         if (!strcmp(arg, "--date-order")) {
 885                                 revs->lifo = 0;
 886                                 revs->topo_order = 1;
 887                                 continue;
 888                         }
 889                         if (!strcmp(arg, "--parents")) {
 890                                 revs->parents = 1;
 891                                 continue;
 892                         }
 893                         if (!strcmp(arg, "--dense")) {
 894                                 revs->dense = 1;
 895                                 continue;
 896                         }
 897                         if (!strcmp(arg, "--sparse")) {
 898                                 revs->dense = 0;
 899                                 continue;
 900                         }
 901                         if (!strcmp(arg, "--remove-empty")) {
 902                                 revs->remove_empty_trees = 1;
 903                                 continue;
 904                         }
 905                         if (!strcmp(arg, "--no-merges")) {
 906                                 revs->no_merges = 1;
 907                                 continue;
 908                         }
 909                         if (!strcmp(arg, "--boundary")) {
 910                                 revs->boundary = 1;
 911                                 continue;
 912                         }
 913                         if (!strcmp(arg, "--left-right")) {
 914                                 revs->left_right = 1;
 915                                 continue;
 916                         }
 917                         if (!strcmp(arg, "--objects")) {
 918                                 revs->tag_objects = 1;
 919                                 revs->tree_objects = 1;
 920                                 revs->blob_objects = 1;
 921                                 continue;
 922                         }
 923                         if (!strcmp(arg, "--objects-edge")) {
 924                                 revs->tag_objects = 1;
 925                                 revs->tree_objects = 1;
 926                                 revs->blob_objects = 1;
 927                                 revs->edge_hint = 1;
 928                                 continue;
 929                         }
 930                         if (!strcmp(arg, "--unpacked")) {
 931                                 revs->unpacked = 1;
 932                                 free(revs->ignore_packed);
 933                                 revs->ignore_packed = NULL;
 934                                 revs->num_ignore_packed = 0;
 935                                 continue;
 936                         }
 937                         if (!prefixcmp(arg, "--unpacked=")) {
 938                                 revs->unpacked = 1;
 939                                 add_ignore_packed(revs, arg+11);
 940                                 continue;
 941                         }
 942                         if (!strcmp(arg, "-r")) {
 943                                 revs->diff = 1;
 944                                 revs->diffopt.recursive = 1;
 945                                 continue;
 946                         }
 947                         if (!strcmp(arg, "-t")) {
 948                                 revs->diff = 1;
 949                                 revs->diffopt.recursive = 1;
 950                                 revs->diffopt.tree_in_recursive = 1;
 951                                 continue;
 952                         }
 953                         if (!strcmp(arg, "-m")) {
 954                                 revs->ignore_merges = 0;
 955                                 continue;
 956                         }
 957                         if (!strcmp(arg, "-c")) {
 958                                 revs->diff = 1;
 959                                 revs->dense_combined_merges = 0;
 960                                 revs->combine_merges = 1;
 961                                 continue;
 962                         }
 963                         if (!strcmp(arg, "--cc")) {
 964                                 revs->diff = 1;
 965                                 revs->dense_combined_merges = 1;
 966                                 revs->combine_merges = 1;
 967                                 continue;
 968                         }
 969                         if (!strcmp(arg, "-v")) {
 970                                 revs->verbose_header = 1;
 971                                 continue;
 972                         }
 973                         if (!prefixcmp(arg, "--pretty")) {
 974                                 revs->verbose_header = 1;
 975                                 revs->commit_format = get_commit_format(arg+8);
 976                                 continue;
 977                         }
 978                         if (!strcmp(arg, "--root")) {
 979                                 revs->show_root_diff = 1;
 980                                 continue;
 981                         }
 982                         if (!strcmp(arg, "--no-commit-id")) {
 983                                 revs->no_commit_id = 1;
 984                                 continue;
 985                         }
 986                         if (!strcmp(arg, "--always")) {
 987                                 revs->always_show_header = 1;
 988                                 continue;
 989                         }
 990                         if (!strcmp(arg, "--no-abbrev")) {
 991                                 revs->abbrev = 0;
 992                                 continue;
 993                         }
 994                         if (!strcmp(arg, "--abbrev")) {
 995                                 revs->abbrev = DEFAULT_ABBREV;
 996                                 continue;
 997                         }
 998                         if (!prefixcmp(arg, "--abbrev=")) {
 999                                 revs->abbrev = strtoul(arg + 9, NULL, 10);
1000                                 if (revs->abbrev < MINIMUM_ABBREV)
1001                                         revs->abbrev = MINIMUM_ABBREV;
1002                                 else if (revs->abbrev > 40)
1003                                         revs->abbrev = 40;
1004                                 continue;
1005                         }
1006                         if (!strcmp(arg, "--abbrev-commit")) {
1007                                 revs->abbrev_commit = 1;
1008                                 continue;
1009                         }
1010                         if (!strcmp(arg, "--full-diff")) {
1011                                 revs->diff = 1;
1012                                 revs->full_diff = 1;
1013                                 continue;
1014                         }
1015                         if (!strcmp(arg, "--full-history")) {
1016                                 revs->simplify_history = 0;
1017                                 continue;
1018                         }
1019                         if (!strcmp(arg, "--relative-date")) {
1020                                 revs->relative_date = 1;
1021                                 continue;
1022                         }
1023
1024                         /*
1025                          * Grepping the commit log
1026                          */
1027                         if (!prefixcmp(arg, "--author=")) {
1028                                 add_header_grep(revs, "author", arg+9);
1029                                 continue;
1030                         }
1031                         if (!prefixcmp(arg, "--committer=")) {
1032                                 add_header_grep(revs, "committer", arg+12);
1033                                 continue;
1034                         }
1035                         if (!prefixcmp(arg, "--grep=")) {
1036                                 add_message_grep(revs, arg+7);
1037                                 continue;
1038                         }
1039                         if (!strcmp(arg, "--all-match")) {
1040                                 all_match = 1;
1041                                 continue;
1042                         }
1043                         if (!prefixcmp(arg, "--encoding=")) {
1044                                 arg += 11;
1045                                 if (strcmp(arg, "none"))
1046                                         git_log_output_encoding = xstrdup(arg);
1047                                 else
1048                                         git_log_output_encoding = "";
1049                                 continue;
1050                         }
1051                         if (!strcmp(arg, "--reverse")) {
1052                                 revs->reverse ^= 1;
1053                                 continue;
1054                         }
1055
1056                         opts = diff_opt_parse(&revs->diffopt, argv+i, argc-i);
1057                         if (opts > 0) {
1058                                 revs->diff = 1;
1059                                 i += opts - 1;
1060                                 continue;
1061                         }
1062                         *unrecognized++ = arg;
1063                         left++;
1064                         continue;
1065                 }
1066
1067                 if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
1068                         int j;
1069                         if (seen_dashdash || *arg == '^')
1070                                 die("bad revision '%s'", arg);
1071
1072                         /* If we didn't have a "--":
1073                          * (1) all filenames must exist;
1074                          * (2) all rev-args must not be interpretable
1075                          *     as a valid filename.
1076                          * but the latter we have checked in the main loop.
1077                          */
1078                         for (j = i; j < argc; j++)
1079                                 verify_filename(revs->prefix, argv[j]);
1080
1081                         revs->prune_data = get_pathspec(revs->prefix,
1082                                                         argv + i);
1083                         break;
1084                 }
1085         }
1086
1087         if (show_merge)
1088                 prepare_show_merge(revs);
1089         if (def && !revs->pending.nr) {
1090                 unsigned char sha1[20];
1091                 struct object *object;
1092                 if (get_sha1(def, sha1))
1093                         die("bad default revision '%s'", def);
1094                 object = get_reference(revs, def, sha1, 0);
1095                 add_pending_object(revs, object, def);
1096         }
1097
1098         if (revs->topo_order)
1099                 revs->limited = 1;
1100
1101         if (revs->prune_data) {
1102                 diff_tree_setup_paths(revs->prune_data, &revs->pruning);
1103                 revs->prune_fn = try_to_simplify_commit;
1104                 if (!revs->full_diff)
1105                         diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
1106         }
1107         if (revs->combine_merges) {
1108                 revs->ignore_merges = 0;
1109                 if (revs->dense_combined_merges && !revs->diffopt.output_format)
1110                         revs->diffopt.output_format = DIFF_FORMAT_PATCH;
1111         }
1112         revs->diffopt.abbrev = revs->abbrev;
1113         if (diff_setup_done(&revs->diffopt) < 0)
1114                 die("diff_setup_done failed");
1115
1116         if (revs->grep_filter) {
1117                 revs->grep_filter->all_match = all_match;
1118                 compile_grep_patterns(revs->grep_filter);
1119         }
1120
1121         return left;
1122 }
1123
1124 void prepare_revision_walk(struct rev_info *revs)
1125 {
1126         int nr = revs->pending.nr;
1127         struct object_array_entry *e, *list;
1128
1129         e = list = revs->pending.objects;
1130         revs->pending.nr = 0;
1131         revs->pending.alloc = 0;
1132         revs->pending.objects = NULL;
1133         while (--nr >= 0) {
1134                 struct commit *commit = handle_commit(revs, e->item, e->name);
1135                 if (commit) {
1136                         if (!(commit->object.flags & SEEN)) {
1137                                 commit->object.flags |= SEEN;
1138                                 insert_by_date(commit, &revs->commits);
1139                         }
1140                 }
1141                 e++;
1142         }
1143         free(list);
1144
1145         if (revs->no_walk)
1146                 return;
1147         if (revs->limited)
1148                 limit_list(revs);
1149         if (revs->topo_order)
1150                 sort_in_topological_order_fn(&revs->commits, revs->lifo,
1151                                              revs->topo_setter,
1152                                              revs->topo_getter);
1153 }
1154
1155 static int rewrite_one(struct rev_info *revs, struct commit **pp)
1156 {
1157         for (;;) {
1158                 struct commit *p = *pp;
1159                 if (!revs->limited)
1160                         add_parents_to_list(revs, p, &revs->commits);
1161                 if (p->parents && p->parents->next)
1162                         return 0;
1163                 if (p->object.flags & (TREECHANGE | UNINTERESTING))
1164                         return 0;
1165                 if (!p->parents)
1166                         return -1;
1167                 *pp = p->parents->item;
1168         }
1169 }
1170
1171 static void rewrite_parents(struct rev_info *revs, struct commit *commit)
1172 {
1173         struct commit_list **pp = &commit->parents;
1174         while (*pp) {
1175                 struct commit_list *parent = *pp;
1176                 if (rewrite_one(revs, &parent->item) < 0) {
1177                         *pp = parent->next;
1178                         continue;
1179                 }
1180                 pp = &parent->next;
1181         }
1182 }
1183
1184 static int commit_match(struct commit *commit, struct rev_info *opt)
1185 {
1186         if (!opt->grep_filter)
1187                 return 1;
1188         return grep_buffer(opt->grep_filter,
1189                            NULL, /* we say nothing, not even filename */
1190                            commit->buffer, strlen(commit->buffer));
1191 }
1192
1193 static struct commit *get_revision_1(struct rev_info *revs)
1194 {
1195         if (!revs->commits)
1196                 return NULL;
1197
1198         do {
1199                 struct commit_list *entry = revs->commits;
1200                 struct commit *commit = entry->item;
1201
1202                 revs->commits = entry->next;
1203                 free(entry);
1204
1205                 if (revs->reflog_info)
1206                         fake_reflog_parent(revs->reflog_info, commit);
1207
1208                 /*
1209                  * If we haven't done the list limiting, we need to look at
1210                  * the parents here. We also need to do the date-based limiting
1211                  * that we'd otherwise have done in limit_list().
1212                  */
1213                 if (!revs->limited) {
1214                         if (revs->max_age != -1 &&
1215                             (commit->date < revs->max_age))
1216                                 continue;
1217                         add_parents_to_list(revs, commit, &revs->commits);
1218                 }
1219                 if (commit->object.flags & SHOWN)
1220                         continue;
1221
1222                 if (revs->unpacked && has_sha1_pack(commit->object.sha1,
1223                                                     revs->ignore_packed))
1224                     continue;
1225
1226                 if (commit->object.flags & UNINTERESTING)
1227                         continue;
1228                 if (revs->min_age != -1 && (commit->date > revs->min_age))
1229                         continue;
1230                 if (revs->no_merges &&
1231                     commit->parents && commit->parents->next)
1232                         continue;
1233                 if (!commit_match(commit, revs))
1234                         continue;
1235                 if (revs->prune_fn && revs->dense) {
1236                         /* Commit without changes? */
1237                         if (!(commit->object.flags & TREECHANGE)) {
1238                                 /* drop merges unless we want parenthood */
1239                                 if (!revs->parents)
1240                                         continue;
1241                                 /* non-merge - always ignore it */
1242                                 if (!commit->parents || !commit->parents->next)
1243                                         continue;
1244                         }
1245                         if (revs->parents)
1246                                 rewrite_parents(revs, commit);
1247                 }
1248                 return commit;
1249         } while (revs->commits);
1250         return NULL;
1251 }
1252
1253 static void gc_boundary(struct object_array *array)
1254 {
1255         unsigned nr = array->nr;
1256         unsigned alloc = array->alloc;
1257         struct object_array_entry *objects = array->objects;
1258
1259         if (alloc <= nr) {
1260                 unsigned i, j;
1261                 for (i = j = 0; i < nr; i++) {
1262                         if (objects[i].item->flags & SHOWN)
1263                                 continue;
1264                         if (i != j)
1265                                 objects[j] = objects[i];
1266                         j++;
1267                 }
1268                 for (i = j; i < nr; i++)
1269                         objects[i].item = NULL;
1270                 array->nr = j;
1271         }
1272 }
1273
1274 struct commit *get_revision(struct rev_info *revs)
1275 {
1276         struct commit *c = NULL;
1277         struct commit_list *l;
1278
1279         if (revs->boundary == 2) {
1280                 unsigned i;
1281                 struct object_array *array = &revs->boundary_commits;
1282                 struct object_array_entry *objects = array->objects;
1283                 for (i = 0; i < array->nr; i++) {
1284                         c = (struct commit *)(objects[i].item);
1285                         if (!c)
1286                                 continue;
1287                         if (!(c->object.flags & CHILD_SHOWN))
1288                                 continue;
1289                         if (!(c->object.flags & SHOWN))
1290                                 break;
1291                 }
1292                 if (array->nr <= i)
1293                         return NULL;
1294
1295                 c->object.flags |= SHOWN | BOUNDARY;
1296                 return c;
1297         }
1298
1299         if (revs->reverse) {
1300                 int limit = -1;
1301
1302                 if (0 <= revs->max_count) {
1303                         limit = revs->max_count;
1304                         if (0 < revs->skip_count)
1305                                 limit += revs->skip_count;
1306                 }
1307                 l = NULL;
1308                 while ((c = get_revision_1(revs))) {
1309                         commit_list_insert(c, &l);
1310                         if ((0 < limit) && !--limit)
1311                                 break;
1312                 }
1313                 revs->commits = l;
1314                 revs->reverse = 0;
1315                 revs->max_count = -1;
1316                 c = NULL;
1317         }
1318
1319         /*
1320          * Now pick up what they want to give us
1321          */
1322         c = get_revision_1(revs);
1323         if (c) {
1324                 while (0 < revs->skip_count) {
1325                         revs->skip_count--;
1326                         c = get_revision_1(revs);
1327                         if (!c)
1328                                 break;
1329                 }
1330         }
1331
1332         /*
1333          * Check the max_count.
1334          */
1335         switch (revs->max_count) {
1336         case -1:
1337                 break;
1338         case 0:
1339                 c = NULL;
1340                 break;
1341         default:
1342                 revs->max_count--;
1343         }
1344
1345         if (c)
1346                 c->object.flags |= SHOWN;
1347
1348         if (!revs->boundary) {
1349                 return c;
1350         }
1351
1352         if (!c) {
1353                 /*
1354                  * get_revision_1() runs out the commits, and
1355                  * we are done computing the boundaries.
1356                  * switch to boundary commits output mode.
1357                  */
1358                 revs->boundary = 2;
1359                 return get_revision(revs);
1360         }
1361
1362         /*
1363          * boundary commits are the commits that are parents of the
1364          * ones we got from get_revision_1() but they themselves are
1365          * not returned from get_revision_1().  Before returning
1366          * 'c', we need to mark its parents that they could be boundaries.
1367          */
1368
1369         for (l = c->parents; l; l = l->next) {
1370                 struct object *p;
1371                 p = &(l->item->object);
1372                 if (p->flags & (CHILD_SHOWN | SHOWN))
1373                         continue;
1374                 p->flags |= CHILD_SHOWN;
1375                 gc_boundary(&revs->boundary_commits);
1376                 add_object_array(p, NULL, &revs->boundary_commits);
1377         }
1378
1379         return c;
1380 }