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