git.oblomov.eu Git - git/blob - 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         int add, rest;
 354
 355         if (commit->object.flags & ADDED)
 356                 return;
 357         commit->object.flags |= ADDED;
 358
 359         /*
 360          * If the commit is uninteresting, don't try to
 361          * prune parents - we want the maximal uninteresting
 362          * set.
 363          *
 364          * Normally we haven't parsed the parent
 365          * yet, so we won't have a parent of a parent
 366          * here. However, it may turn out that we've
 367          * reached this commit some other way (where it
 368          * wasn't uninteresting), in which case we need
 369          * to mark its parents recursively too..
 370          */
 371         if (commit->object.flags & UNINTERESTING) {
 372                 while (parent) {
 373                         struct commit *p = parent->item;
 374                         parent = parent->next;
 375                         parse_commit(p);
 376                         p->object.flags |= UNINTERESTING;
 377                         if (p->parents)
 378                                 mark_parents_uninteresting(p);
 379                         if (p->object.flags & SEEN)
 380                                 continue;
 381                         p->object.flags |= SEEN;
 382                         insert_by_date(p, list);
 383                 }
 384                 return;
 385         }
 386
 387         /*
 388          * Ok, the commit wasn't uninteresting. Try to
 389          * simplify the commit history and find the parent
 390          * that has no differences in the path set if one exists.
 391          */
 392         if (revs->prune_fn)
 393                 revs->prune_fn(revs, commit);
 394
 395         if (revs->no_walk)
 396                 return;
 397
 398         left_flag = (commit->object.flags & SYMMETRIC_LEFT);
 399
 400         rest = !revs->first_parent_only;
 401         for (parent = commit->parents, add = 1; parent; add = rest) {
 402                 struct commit *p = parent->item;
 403
 404                 parent = parent->next;
 405                 parse_commit(p);
 406                 p->object.flags |= left_flag;
 407                 if (p->object.flags & SEEN)
 408                         continue;
 409                 p->object.flags |= SEEN;
 410                 if (add)
 411                         insert_by_date(p, list);
 412         }
 413 }
 414
 415 static void limit_list(struct rev_info *revs)
 416 {
 417         struct commit_list *list = revs->commits;
 418         struct commit_list *newlist = NULL;
 419         struct commit_list **p = &newlist;
 420
 421         while (list) {
 422                 struct commit_list *entry = list;
 423                 struct commit *commit = list->item;
 424                 struct object *obj = &commit->object;
 425
 426                 list = list->next;
 427                 free(entry);
 428
 429                 if (revs->max_age != -1 && (commit->date < revs->max_age))
 430                         obj->flags |= UNINTERESTING;
 431                 add_parents_to_list(revs, commit, &list);
 432                 if (obj->flags & UNINTERESTING) {
 433                         mark_parents_uninteresting(commit);
 434                         if (everybody_uninteresting(list))
 435                                 break;
 436                         continue;
 437                 }
 438                 if (revs->min_age != -1 && (commit->date > revs->min_age))
 439                         continue;
 440                 p = &commit_list_insert(commit, p)->next;
 441         }
 442         revs->commits = newlist;
 443 }
 444
 445 struct all_refs_cb {
 446         int all_flags;
 447         int warned_bad_reflog;
 448         struct rev_info *all_revs;
 449         const char *name_for_errormsg;
 450 };
 451
 452 static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 453 {
 454         struct all_refs_cb *cb = cb_data;
 455         struct object *object = get_reference(cb->all_revs, path, sha1,
 456                                               cb->all_flags);
 457         add_pending_object(cb->all_revs, object, path);
 458         return 0;
 459 }
 460
 461 static void handle_all(struct rev_info *revs, unsigned flags)
 462 {
 463         struct all_refs_cb cb;
 464         cb.all_revs = revs;
 465         cb.all_flags = flags;
 466         for_each_ref(handle_one_ref, &cb);
 467 }
 468
 469 static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
 470 {
 471         struct all_refs_cb *cb = cb_data;
 472         if (!is_null_sha1(sha1)) {
 473                 struct object *o = parse_object(sha1);
 474                 if (o) {
 475                         o->flags |= cb->all_flags;
 476                         add_pending_object(cb->all_revs, o, "");
 477                 }
 478                 else if (!cb->warned_bad_reflog) {
 479                         warn("reflog of '%s' references pruned commits",
 480                                 cb->name_for_errormsg);
 481                         cb->warned_bad_reflog = 1;
 482                 }
 483         }
 484 }
 485
 486 static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 487                 const char *email, unsigned long timestamp, int tz,
 488                 const char *message, void *cb_data)
 489 {
 490         handle_one_reflog_commit(osha1, cb_data);
 491         handle_one_reflog_commit(nsha1, cb_data);
 492         return 0;
 493 }
 494
 495 static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 496 {
 497         struct all_refs_cb *cb = cb_data;
 498         cb->warned_bad_reflog = 0;
 499         cb->name_for_errormsg = path;
 500         for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
 501         return 0;
 502 }
 503
 504 static void handle_reflog(struct rev_info *revs, unsigned flags)
 505 {
 506         struct all_refs_cb cb;
 507         cb.all_revs = revs;
 508         cb.all_flags = flags;
 509         for_each_reflog(handle_one_reflog, &cb);
 510 }
 511
 512 static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
 513 {
 514         unsigned char sha1[20];
 515         struct object *it;
 516         struct commit *commit;
 517         struct commit_list *parents;
 518
 519         if (*arg == '^') {
 520                 flags ^= UNINTERESTING;
 521                 arg++;
 522         }
 523         if (get_sha1(arg, sha1))
 524                 return 0;
 525         while (1) {
 526                 it = get_reference(revs, arg, sha1, 0);
 527                 if (it->type != OBJ_TAG)
 528                         break;
 529                 hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
 530         }
 531         if (it->type != OBJ_COMMIT)
 532                 return 0;
 533         commit = (struct commit *)it;
 534         for (parents = commit->parents; parents; parents = parents->next) {
 535                 it = &parents->item->object;
 536                 it->flags |= flags;
 537                 add_pending_object(revs, it, arg);
 538         }
 539         return 1;
 540 }
 541
 542 void init_revisions(struct rev_info *revs, const char *prefix)
 543 {
 544         memset(revs, 0, sizeof(*revs));
 545
 546         revs->abbrev = DEFAULT_ABBREV;
 547         revs->ignore_merges = 1;
 548         revs->simplify_history = 1;
 549         revs->pruning.recursive = 1;
 550         revs->pruning.add_remove = file_add_remove;
 551         revs->pruning.change = file_change;
 552         revs->lifo = 1;
 553         revs->dense = 1;
 554         revs->prefix = prefix;
 555         revs->max_age = -1;
 556         revs->min_age = -1;
 557         revs->skip_count = -1;
 558         revs->max_count = -1;
 559
 560         revs->prune_fn = NULL;
 561         revs->prune_data = NULL;
 562
 563         revs->topo_setter = topo_sort_default_setter;
 564         revs->topo_getter = topo_sort_default_getter;
 565
 566         revs->commit_format = CMIT_FMT_DEFAULT;
 567
 568         diff_setup(&revs->diffopt);
 569 }
 570
 571 static void add_pending_commit_list(struct rev_info *revs,
 572                                     struct commit_list *commit_list,
 573                                     unsigned int flags)
 574 {
 575         while (commit_list) {
 576                 struct object *object = &commit_list->item->object;
 577                 object->flags |= flags;
 578                 add_pending_object(revs, object, sha1_to_hex(object->sha1));
 579                 commit_list = commit_list->next;
 580         }
 581 }
 582
 583 static void prepare_show_merge(struct rev_info *revs)
 584 {
 585         struct commit_list *bases;
 586         struct commit *head, *other;
 587         unsigned char sha1[20];
 588         const char **prune = NULL;
 589         int i, prune_num = 1; /* counting terminating NULL */
 590
 591         if (get_sha1("HEAD", sha1) || !(head = lookup_commit(sha1)))
 592                 die("--merge without HEAD?");
 593         if (get_sha1("MERGE_HEAD", sha1) || !(other = lookup_commit(sha1)))
 594                 die("--merge without MERGE_HEAD?");
 595         add_pending_object(revs, &head->object, "HEAD");
 596         add_pending_object(revs, &other->object, "MERGE_HEAD");
 597         bases = get_merge_bases(head, other, 1);
 598         while (bases) {
 599                 struct commit *it = bases->item;
 600                 struct commit_list *n = bases->next;
 601                 free(bases);
 602                 bases = n;
 603                 it->object.flags |= UNINTERESTING;
 604                 add_pending_object(revs, &it->object, "(merge-base)");
 605         }
 606
 607         if (!active_nr)
 608                 read_cache();
 609         for (i = 0; i < active_nr; i++) {
 610                 struct cache_entry *ce = active_cache[i];
 611                 if (!ce_stage(ce))
 612                         continue;
 613                 if (ce_path_match(ce, revs->prune_data)) {
 614                         prune_num++;
 615                         prune = xrealloc(prune, sizeof(*prune) * prune_num);
 616                         prune[prune_num-2] = ce->name;
 617                         prune[prune_num-1] = NULL;
 618                 }
 619                 while ((i+1 < active_nr) &&
 620                        ce_same_name(ce, active_cache[i+1]))
 621                         i++;
 622         }
 623         revs->prune_data = prune;
 624 }
 625
 626 int handle_revision_arg(const char *arg, struct rev_info *revs,
 627                         int flags,
 628                         int cant_be_filename)
 629 {
 630         char *dotdot;
 631         struct object *object;
 632         unsigned char sha1[20];
 633         int local_flags;
 634
 635         dotdot = strstr(arg, "..");
 636         if (dotdot) {
 637                 unsigned char from_sha1[20];
 638                 const char *next = dotdot + 2;
 639                 const char *this = arg;
 640                 int symmetric = *next == '.';
 641                 unsigned int flags_exclude = flags ^ UNINTERESTING;
 642
 643                 *dotdot = 0;
 644                 next += symmetric;
 645
 646                 if (!*next)
 647                         next = "HEAD";
 648                 if (dotdot == arg)
 649                         this = "HEAD";
 650                 if (!get_sha1(this, from_sha1) &&
 651                     !get_sha1(next, sha1)) {
 652                         struct commit *a, *b;
 653                         struct commit_list *exclude;
 654
 655                         a = lookup_commit_reference(from_sha1);
 656                         b = lookup_commit_reference(sha1);
 657                         if (!a || !b) {
 658                                 die(symmetric ?
 659                                     "Invalid symmetric difference expression %s...%s" :
 660                                     "Invalid revision range %s..%s",
 661                                     arg, next);
 662                         }
 663
 664                         if (!cant_be_filename) {
 665                                 *dotdot = '.';
 666                                 verify_non_filename(revs->prefix, arg);
 667                         }
 668
 669                         if (symmetric) {
 670                                 exclude = get_merge_bases(a, b, 1);
 671                                 add_pending_commit_list(revs, exclude,
 672                                                         flags_exclude);
 673                                 free_commit_list(exclude);
 674                                 a->object.flags |= flags | SYMMETRIC_LEFT;
 675                         } else
 676                                 a->object.flags |= flags_exclude;
 677                         b->object.flags |= flags;
 678                         add_pending_object(revs, &a->object, this);
 679                         add_pending_object(revs, &b->object, next);
 680                         return 0;
 681                 }
 682                 *dotdot = '.';
 683         }
 684         dotdot = strstr(arg, "^@");
 685         if (dotdot && !dotdot[2]) {
 686                 *dotdot = 0;
 687                 if (add_parents_only(revs, arg, flags))
 688                         return 0;
 689                 *dotdot = '^';
 690         }
 691         dotdot = strstr(arg, "^!");
 692         if (dotdot && !dotdot[2]) {
 693                 *dotdot = 0;
 694                 if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
 695                         *dotdot = '^';
 696         }
 697
 698         local_flags = 0;
 699         if (*arg == '^') {
 700                 local_flags = UNINTERESTING;
 701                 arg++;
 702         }
 703         if (get_sha1(arg, sha1))
 704                 return -1;
 705         if (!cant_be_filename)
 706                 verify_non_filename(revs->prefix, arg);
 707         object = get_reference(revs, arg, sha1, flags ^ local_flags);
 708         add_pending_object(revs, object, arg);
 709         return 0;
 710 }
 711
 712 static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
 713 {
 714         if (!revs->grep_filter) {
 715                 struct grep_opt *opt = xcalloc(1, sizeof(*opt));
 716                 opt->status_only = 1;
 717                 opt->pattern_tail = &(opt->pattern_list);
 718                 opt->regflags = REG_NEWLINE;
 719                 revs->grep_filter = opt;
 720         }
 721         append_grep_pattern(revs->grep_filter, ptn,
 722                             "command line", 0, what);
 723 }
 724
 725 static void add_header_grep(struct rev_info *revs, const char *field, const char *pattern)
 726 {
 727         char *pat;
 728         const char *prefix;
 729         int patlen, fldlen;
 730
 731         fldlen = strlen(field);
 732         patlen = strlen(pattern);
 733         pat = xmalloc(patlen + fldlen + 10);
 734         prefix = ".*";
 735         if (*pattern == '^') {
 736                 prefix = "";
 737                 pattern++;
 738         }
 739         sprintf(pat, "^%s %s%s", field, prefix, pattern);
 740         add_grep(revs, pat, GREP_PATTERN_HEAD);
 741 }
 742
 743 static void add_message_grep(struct rev_info *revs, const char *pattern)
 744 {
 745         add_grep(revs, pattern, GREP_PATTERN_BODY);
 746 }
 747
 748 static void add_ignore_packed(struct rev_info *revs, const char *name)
 749 {
 750         int num = ++revs->num_ignore_packed;
 751
 752         revs->ignore_packed = xrealloc(revs->ignore_packed,
 753                                        sizeof(const char **) * (num + 1));
 754         revs->ignore_packed[num-1] = name;
 755         revs->ignore_packed[num] = NULL;
 756 }
 757
 758 /*
 759  * Parse revision information, filling in the "rev_info" structure,
 760  * and removing the used arguments from the argument list.
 761  *
 762  * Returns the number of arguments left that weren't recognized
 763  * (which are also moved to the head of the argument list)
 764  */
 765 int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
 766 {
 767         int i, flags, seen_dashdash, show_merge;
 768         const char **unrecognized = argv + 1;
 769         int left = 1;
 770         int all_match = 0;
 771
 772         /* First, search for "--" */
 773         seen_dashdash = 0;
 774         for (i = 1; i < argc; i++) {
 775                 const char *arg = argv[i];
 776                 if (strcmp(arg, "--"))
 777                         continue;
 778                 argv[i] = NULL;
 779                 argc = i;
 780                 revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
 781                 seen_dashdash = 1;
 782                 break;
 783         }
 784
 785         flags = show_merge = 0;
 786         for (i = 1; i < argc; i++) {
 787                 const char *arg = argv[i];
 788                 if (*arg == '-') {
 789                         int opts;
 790                         if (!prefixcmp(arg, "--max-count=")) {
 791                                 revs->max_count = atoi(arg + 12);
 792                                 continue;
 793                         }
 794                         if (!prefixcmp(arg, "--skip=")) {
 795                                 revs->skip_count = atoi(arg + 7);
 796                                 continue;
 797                         }
 798                         /* accept -<digit>, like traditional "head" */
 799                         if ((*arg == '-') && isdigit(arg[1])) {
 800                                 revs->max_count = atoi(arg + 1);
 801                                 continue;
 802                         }
 803                         if (!strcmp(arg, "-n")) {
 804                                 if (argc <= i + 1)
 805                                         die("-n requires an argument");
 806                                 revs->max_count = atoi(argv[++i]);
 807                                 continue;
 808                         }
 809                         if (!prefixcmp(arg, "-n")) {
 810                                 revs->max_count = atoi(arg + 2);
 811                                 continue;
 812                         }
 813                         if (!prefixcmp(arg, "--max-age=")) {
 814                                 revs->max_age = atoi(arg + 10);
 815                                 continue;
 816                         }
 817                         if (!prefixcmp(arg, "--since=")) {
 818                                 revs->max_age = approxidate(arg + 8);
 819                                 continue;
 820                         }
 821                         if (!prefixcmp(arg, "--after=")) {
 822                                 revs->max_age = approxidate(arg + 8);
 823                                 continue;
 824                         }
 825                         if (!prefixcmp(arg, "--min-age=")) {
 826                                 revs->min_age = atoi(arg + 10);
 827                                 continue;
 828                         }
 829                         if (!prefixcmp(arg, "--before=")) {
 830                                 revs->min_age = approxidate(arg + 9);
 831                                 continue;
 832                         }
 833                         if (!prefixcmp(arg, "--until=")) {
 834                                 revs->min_age = approxidate(arg + 8);
 835                                 continue;
 836                         }
 837                         if (!strcmp(arg, "--all")) {
 838                                 handle_all(revs, flags);
 839                                 continue;
 840                         }
 841                         if (!strcmp(arg, "--first-parent")) {
 842                                 revs->first_parent_only = 1;
 843                                 continue;
 844                         }
 845                         if (!strcmp(arg, "--reflog")) {
 846                                 handle_reflog(revs, flags);
 847                                 continue;
 848                         }
 849                         if (!strcmp(arg, "-g") ||
 850                                         !strcmp(arg, "--walk-reflogs")) {
 851                                 init_reflog_walk(&revs->reflog_info);
 852                                 continue;
 853                         }
 854                         if (!strcmp(arg, "--not")) {
 855                                 flags ^= UNINTERESTING;
 856                                 continue;
 857                         }
 858                         if (!strcmp(arg, "--default")) {
 859                                 if (++i >= argc)
 860                                         die("bad --default argument");
 861                                 def = argv[i];
 862                                 continue;
 863                         }
 864                         if (!strcmp(arg, "--merge")) {
 865                                 show_merge = 1;
 866                                 continue;
 867                         }
 868                         if (!strcmp(arg, "--topo-order")) {
 869                                 revs->topo_order = 1;
 870                                 continue;
 871                         }
 872                         if (!strcmp(arg, "--date-order")) {
 873                                 revs->lifo = 0;
 874                                 revs->topo_order = 1;
 875                                 continue;
 876                         }
 877                         if (!strcmp(arg, "--parents")) {
 878                                 revs->parents = 1;
 879                                 continue;
 880                         }
 881                         if (!strcmp(arg, "--dense")) {
 882                                 revs->dense = 1;
 883                                 continue;
 884                         }
 885                         if (!strcmp(arg, "--sparse")) {
 886                                 revs->dense = 0;
 887                                 continue;
 888                         }
 889                         if (!strcmp(arg, "--remove-empty")) {
 890                                 revs->remove_empty_trees = 1;
 891                                 continue;
 892                         }
 893                         if (!strcmp(arg, "--no-merges")) {
 894                                 revs->no_merges = 1;
 895                                 continue;
 896                         }
 897                         if (!strcmp(arg, "--boundary")) {
 898                                 revs->boundary = 1;
 899                                 continue;
 900                         }
 901                         if (!strcmp(arg, "--left-right")) {
 902                                 revs->left_right = 1;
 903                                 continue;
 904                         }
 905                         if (!strcmp(arg, "--objects")) {
 906                                 revs->tag_objects = 1;
 907                                 revs->tree_objects = 1;
 908                                 revs->blob_objects = 1;
 909                                 continue;
 910                         }
 911                         if (!strcmp(arg, "--objects-edge")) {
 912                                 revs->tag_objects = 1;
 913                                 revs->tree_objects = 1;
 914                                 revs->blob_objects = 1;
 915                                 revs->edge_hint = 1;
 916                                 continue;
 917                         }
 918                         if (!strcmp(arg, "--unpacked")) {
 919                                 revs->unpacked = 1;
 920                                 free(revs->ignore_packed);
 921                                 revs->ignore_packed = NULL;
 922                                 revs->num_ignore_packed = 0;
 923                                 continue;
 924                         }
 925                         if (!prefixcmp(arg, "--unpacked=")) {
 926                                 revs->unpacked = 1;
 927                                 add_ignore_packed(revs, arg+11);
 928                                 continue;
 929                         }
 930                         if (!strcmp(arg, "-r")) {
 931                                 revs->diff = 1;
 932                                 revs->diffopt.recursive = 1;
 933                                 continue;
 934                         }
 935                         if (!strcmp(arg, "-t")) {
 936                                 revs->diff = 1;
 937                                 revs->diffopt.recursive = 1;
 938                                 revs->diffopt.tree_in_recursive = 1;
 939                                 continue;
 940                         }
 941                         if (!strcmp(arg, "-m")) {
 942                                 revs->ignore_merges = 0;
 943                                 continue;
 944                         }
 945                         if (!strcmp(arg, "-c")) {
 946                                 revs->diff = 1;
 947                                 revs->dense_combined_merges = 0;
 948                                 revs->combine_merges = 1;
 949                                 continue;
 950                         }
 951                         if (!strcmp(arg, "--cc")) {
 952                                 revs->diff = 1;
 953                                 revs->dense_combined_merges = 1;
 954                                 revs->combine_merges = 1;
 955                                 continue;
 956                         }
 957                         if (!strcmp(arg, "-v")) {
 958                                 revs->verbose_header = 1;
 959                                 continue;
 960                         }
 961                         if (!prefixcmp(arg, "--pretty")) {
 962                                 revs->verbose_header = 1;
 963                                 revs->commit_format = get_commit_format(arg+8);
 964                                 continue;
 965                         }
 966                         if (!strcmp(arg, "--root")) {
 967                                 revs->show_root_diff = 1;
 968                                 continue;
 969                         }
 970                         if (!strcmp(arg, "--no-commit-id")) {
 971                                 revs->no_commit_id = 1;
 972                                 continue;
 973                         }
 974                         if (!strcmp(arg, "--always")) {
 975                                 revs->always_show_header = 1;
 976                                 continue;
 977                         }
 978                         if (!strcmp(arg, "--no-abbrev")) {
 979                                 revs->abbrev = 0;
 980                                 continue;
 981                         }
 982                         if (!strcmp(arg, "--abbrev")) {
 983                                 revs->abbrev = DEFAULT_ABBREV;
 984                                 continue;
 985                         }
 986                         if (!prefixcmp(arg, "--abbrev=")) {
 987                                 revs->abbrev = strtoul(arg + 9, NULL, 10);
 988                                 if (revs->abbrev < MINIMUM_ABBREV)
 989                                         revs->abbrev = MINIMUM_ABBREV;
 990                                 else if (revs->abbrev > 40)
 991                                         revs->abbrev = 40;
 992                                 continue;
 993                         }
 994                         if (!strcmp(arg, "--abbrev-commit")) {
 995                                 revs->abbrev_commit = 1;
 996                                 continue;
 997                         }
 998                         if (!strcmp(arg, "--full-diff")) {
 999                                 revs->diff = 1;
1000                                 revs->full_diff = 1;
1001                                 continue;
1002                         }
1003                         if (!strcmp(arg, "--full-history")) {
1004                                 revs->simplify_history = 0;
1005                                 continue;
1006                         }
1007                         if (!strcmp(arg, "--relative-date")) {
1008                                 revs->relative_date = 1;
1009                                 continue;
1010                         }
1011
1012                         /*
1013                          * Grepping the commit log
1014                          */
1015                         if (!prefixcmp(arg, "--author=")) {
1016                                 add_header_grep(revs, "author", arg+9);
1017                                 continue;
1018                         }
1019                         if (!prefixcmp(arg, "--committer=")) {
1020                                 add_header_grep(revs, "committer", arg+12);
1021                                 continue;
1022                         }
1023                         if (!prefixcmp(arg, "--grep=")) {
1024                                 add_message_grep(revs, arg+7);
1025                                 continue;
1026                         }
1027                         if (!strcmp(arg, "--all-match")) {
1028                                 all_match = 1;
1029                                 continue;
1030                         }
1031                         if (!prefixcmp(arg, "--encoding=")) {
1032                                 arg += 11;
1033                                 if (strcmp(arg, "none"))
1034                                         git_log_output_encoding = strdup(arg);
1035                                 else
1036                                         git_log_output_encoding = "";
1037                                 continue;
1038                         }
1039                         if (!strcmp(arg, "--reverse")) {
1040                                 revs->reverse ^= 1;
1041                                 continue;
1042                         }
1043
1044                         opts = diff_opt_parse(&revs->diffopt, argv+i, argc-i);
1045                         if (opts > 0) {
1046                                 revs->diff = 1;
1047                                 i += opts - 1;
1048                                 continue;
1049                         }
1050                         *unrecognized++ = arg;
1051                         left++;
1052                         continue;
1053                 }
1054
1055                 if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
1056                         int j;
1057                         if (seen_dashdash || *arg == '^')
1058                                 die("bad revision '%s'", arg);
1059
1060                         /* If we didn't have a "--":
1061                          * (1) all filenames must exist;
1062                          * (2) all rev-args must not be interpretable
1063                          *     as a valid filename.
1064                          * but the latter we have checked in the main loop.
1065                          */
1066                         for (j = i; j < argc; j++)
1067                                 verify_filename(revs->prefix, argv[j]);
1068
1069                         revs->prune_data = get_pathspec(revs->prefix,
1070                                                         argv + i);
1071                         break;
1072                 }
1073         }
1074
1075         if (show_merge)
1076                 prepare_show_merge(revs);
1077         if (def && !revs->pending.nr) {
1078                 unsigned char sha1[20];
1079                 struct object *object;
1080                 if (get_sha1(def, sha1))
1081                         die("bad default revision '%s'", def);
1082                 object = get_reference(revs, def, sha1, 0);
1083                 add_pending_object(revs, object, def);
1084         }
1085
1086         if (revs->topo_order)
1087                 revs->limited = 1;
1088
1089         if (revs->prune_data) {
1090                 diff_tree_setup_paths(revs->prune_data, &revs->pruning);
1091                 revs->prune_fn = try_to_simplify_commit;
1092                 if (!revs->full_diff)
1093                         diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
1094         }
1095         if (revs->combine_merges) {
1096                 revs->ignore_merges = 0;
1097                 if (revs->dense_combined_merges && !revs->diffopt.output_format)
1098                         revs->diffopt.output_format = DIFF_FORMAT_PATCH;
1099         }
1100         revs->diffopt.abbrev = revs->abbrev;
1101         if (diff_setup_done(&revs->diffopt) < 0)
1102                 die("diff_setup_done failed");
1103
1104         if (revs->grep_filter) {
1105                 revs->grep_filter->all_match = all_match;
1106                 compile_grep_patterns(revs->grep_filter);
1107         }
1108
1109         return left;
1110 }
1111
1112 void prepare_revision_walk(struct rev_info *revs)
1113 {
1114         int nr = revs->pending.nr;
1115         struct object_array_entry *e, *list;
1116
1117         e = list = revs->pending.objects;
1118         revs->pending.nr = 0;
1119         revs->pending.alloc = 0;
1120         revs->pending.objects = NULL;
1121         while (--nr >= 0) {
1122                 struct commit *commit = handle_commit(revs, e->item, e->name);
1123                 if (commit) {
1124                         if (!(commit->object.flags & SEEN)) {
1125                                 commit->object.flags |= SEEN;
1126                                 insert_by_date(commit, &revs->commits);
1127                         }
1128                 }
1129                 e++;
1130         }
1131         free(list);
1132
1133         if (revs->no_walk)
1134                 return;
1135         if (revs->limited)
1136                 limit_list(revs);
1137         if (revs->topo_order)
1138                 sort_in_topological_order_fn(&revs->commits, revs->lifo,
1139                                              revs->topo_setter,
1140                                              revs->topo_getter);
1141 }
1142
1143 static int rewrite_one(struct rev_info *revs, struct commit **pp)
1144 {
1145         for (;;) {
1146                 struct commit *p = *pp;
1147                 if (!revs->limited)
1148                         add_parents_to_list(revs, p, &revs->commits);
1149                 if (p->parents && p->parents->next)
1150                         return 0;
1151                 if (p->object.flags & (TREECHANGE | UNINTERESTING))
1152                         return 0;
1153                 if (!p->parents)
1154                         return -1;
1155                 *pp = p->parents->item;
1156         }
1157 }
1158
1159 static void rewrite_parents(struct rev_info *revs, struct commit *commit)
1160 {
1161         struct commit_list **pp = &commit->parents;
1162         while (*pp) {
1163                 struct commit_list *parent = *pp;
1164                 if (rewrite_one(revs, &parent->item) < 0) {
1165                         *pp = parent->next;
1166                         continue;
1167                 }
1168                 pp = &parent->next;
1169         }
1170 }
1171
1172 static int commit_match(struct commit *commit, struct rev_info *opt)
1173 {
1174         if (!opt->grep_filter)
1175                 return 1;
1176         return grep_buffer(opt->grep_filter,
1177                            NULL, /* we say nothing, not even filename */
1178                            commit->buffer, strlen(commit->buffer));
1179 }
1180
1181 static struct commit *get_revision_1(struct rev_info *revs)
1182 {
1183         if (!revs->commits)
1184                 return NULL;
1185
1186         do {
1187                 struct commit_list *entry = revs->commits;
1188                 struct commit *commit = entry->item;
1189
1190                 revs->commits = entry->next;
1191                 free(entry);
1192
1193                 if (revs->reflog_info)
1194                         fake_reflog_parent(revs->reflog_info, commit);
1195
1196                 /*
1197                  * If we haven't done the list limiting, we need to look at
1198                  * the parents here. We also need to do the date-based limiting
1199                  * that we'd otherwise have done in limit_list().
1200                  */
1201                 if (!revs->limited) {
1202                         if (revs->max_age != -1 &&
1203                             (commit->date < revs->max_age))
1204                                 continue;
1205                         add_parents_to_list(revs, commit, &revs->commits);
1206                 }
1207                 if (commit->object.flags & SHOWN)
1208                         continue;
1209
1210                 if (revs->unpacked && has_sha1_pack(commit->object.sha1,
1211                                                     revs->ignore_packed))
1212                     continue;
1213
1214                 if (commit->object.flags & UNINTERESTING)
1215                         continue;
1216                 if (revs->min_age != -1 && (commit->date > revs->min_age))
1217                         continue;
1218                 if (revs->no_merges &&
1219                     commit->parents && commit->parents->next)
1220                         continue;
1221                 if (!commit_match(commit, revs))
1222                         continue;
1223                 if (revs->prune_fn && revs->dense) {
1224                         /* Commit without changes? */
1225                         if (!(commit->object.flags & TREECHANGE)) {
1226                                 /* drop merges unless we want parenthood */
1227                                 if (!revs->parents)
1228                                         continue;
1229                                 /* non-merge - always ignore it */
1230                                 if (!commit->parents || !commit->parents->next)
1231                                         continue;
1232                         }
1233                         if (revs->parents)
1234                                 rewrite_parents(revs, commit);
1235                 }
1236                 return commit;
1237         } while (revs->commits);
1238         return NULL;
1239 }
1240
1241 static void gc_boundary(struct object_array *array)
1242 {
1243         unsigned nr = array->nr;
1244         unsigned alloc = array->alloc;
1245         struct object_array_entry *objects = array->objects;
1246
1247         if (alloc <= nr) {
1248                 unsigned i, j;
1249                 for (i = j = 0; i < nr; i++) {
1250                         if (objects[i].item->flags & SHOWN)
1251                                 continue;
1252                         if (i != j)
1253                                 objects[j] = objects[i];
1254                         j++;
1255                 }
1256                 for (i = j; i < nr; i++)
1257                         objects[i].item = NULL;
1258                 array->nr = j;
1259         }
1260 }
1261
1262 struct commit *get_revision(struct rev_info *revs)
1263 {
1264         struct commit *c = NULL;
1265         struct commit_list *l;
1266
1267         if (revs->boundary == 2) {
1268                 unsigned i;
1269                 struct object_array *array = &revs->boundary_commits;
1270                 struct object_array_entry *objects = array->objects;
1271                 for (i = 0; i < array->nr; i++) {
1272                         c = (struct commit *)(objects[i].item);
1273                         if (!c)
1274                                 continue;
1275                         if (!(c->object.flags & CHILD_SHOWN))
1276                                 continue;
1277                         if (!(c->object.flags & SHOWN))
1278                                 break;
1279                 }
1280                 if (array->nr <= i)
1281                         return NULL;
1282
1283                 c->object.flags |= SHOWN | BOUNDARY;
1284                 return c;
1285         }
1286
1287         if (revs->reverse) {
1288                 int limit = -1;
1289
1290                 if (0 <= revs->max_count) {
1291                         limit = revs->max_count;
1292                         if (0 < revs->skip_count)
1293                                 limit += revs->skip_count;
1294                 }
1295                 l = NULL;
1296                 while ((c = get_revision_1(revs))) {
1297                         commit_list_insert(c, &l);
1298                         if ((0 < limit) && !--limit)
1299                                 break;
1300                 }
1301                 revs->commits = l;
1302                 revs->reverse = 0;
1303                 revs->max_count = -1;
1304                 c = NULL;
1305         }
1306
1307         /*
1308          * Now pick up what they want to give us
1309          */
1310         c = get_revision_1(revs);
1311         if (c) {
1312                 while (0 < revs->skip_count) {
1313                         revs->skip_count--;
1314                         c = get_revision_1(revs);
1315                         if (!c)
1316                                 break;
1317                 }
1318         }
1319
1320         /*
1321          * Check the max_count.
1322          */
1323         switch (revs->max_count) {
1324         case -1:
1325                 break;
1326         case 0:
1327                 c = NULL;
1328                 break;
1329         default:
1330                 revs->max_count--;
1331         }
1332
1333         if (c)
1334                 c->object.flags |= SHOWN;
1335
1336         if (!revs->boundary) {
1337                 return c;
1338         }
1339
1340         if (!c) {
1341                 /*
1342                  * get_revision_1() runs out the commits, and
1343                  * we are done computing the boundaries.
1344                  * switch to boundary commits output mode.
1345                  */
1346                 revs->boundary = 2;
1347                 return get_revision(revs);
1348         }
1349
1350         /*
1351          * boundary commits are the commits that are parents of the
1352          * ones we got from get_revision_1() but they themselves are
1353          * not returned from get_revision_1().  Before returning
1354          * 'c', we need to mark its parents that they could be boundaries.
1355          */
1356
1357         for (l = c->parents; l; l = l->next) {
1358                 struct object *p;
1359                 p = &(l->item->object);
1360                 if (p->flags & (CHILD_SHOWN | SHOWN))
1361                         continue;
1362                 p->flags |= CHILD_SHOWN;
1363                 gc_boundary(&revs->boundary_commits);
1364                 add_object_array(p, NULL, &revs->boundary_commits);
1365         }
1366
1367         return c;
1368 }