revision.c

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