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
  10 static char *path_name(struct name_path *path, const char *name)
  11 {
  12         struct name_path *p;
  13         char *n, *m;
  14         int nlen = strlen(name);
  15         int len = nlen + 1;
  16
  17         for (p = path; p; p = p->up) {
  18                 if (p->elem_len)
  19                         len += p->elem_len + 1;
  20         }
  21         n = xmalloc(len);
  22         m = n + len - (nlen + 1);
  23         strcpy(m, name);
  24         for (p = path; p; p = p->up) {
  25                 if (p->elem_len) {
  26                         m -= p->elem_len + 1;
  27                         memcpy(m, p->elem, p->elem_len);
  28                         m[p->elem_len] = '/';
  29                 }
  30         }
  31         return n;
  32 }
  33
  34 struct object_list **add_object(struct object *obj,
  35                                        struct object_list **p,
  36                                        struct name_path *path,
  37                                        const char *name)
  38 {
  39         struct object_list *entry = xmalloc(sizeof(*entry));
  40         entry->item = obj;
  41         entry->next = *p;
  42         entry->name = path_name(path, name);
  43         *p = entry;
  44         return &entry->next;
  45 }
  46
  47 static void mark_blob_uninteresting(struct blob *blob)
  48 {
  49         if (blob->object.flags & UNINTERESTING)
  50                 return;
  51         blob->object.flags |= UNINTERESTING;
  52 }
  53
  54 void mark_tree_uninteresting(struct tree *tree)
  55 {
  56         struct object *obj = &tree->object;
  57         struct tree_entry_list *entry;
  58
  59         if (obj->flags & UNINTERESTING)
  60                 return;
  61         obj->flags |= UNINTERESTING;
  62         if (!has_sha1_file(obj->sha1))
  63                 return;
  64         if (parse_tree(tree) < 0)
  65                 die("bad tree %s", sha1_to_hex(obj->sha1));
  66         entry = create_tree_entry_list(tree);
  67         while (entry) {
  68                 struct tree_entry_list *next = entry->next;
  69                 if (entry->directory)
  70                         mark_tree_uninteresting(lookup_tree(entry->sha1));
  71                 else
  72                         mark_blob_uninteresting(lookup_blob(entry->sha1));
  73                 free(entry);
  74                 entry = next;
  75         }
  76 }
  77
  78 void mark_parents_uninteresting(struct commit *commit)
  79 {
  80         struct commit_list *parents = commit->parents;
  81
  82         while (parents) {
  83                 struct commit *commit = parents->item;
  84                 if (!(commit->object.flags & UNINTERESTING)) {
  85                         commit->object.flags |= UNINTERESTING;
  86
  87                         /*
  88                          * Normally we haven't parsed the parent
  89                          * yet, so we won't have a parent of a parent
  90                          * here. However, it may turn out that we've
  91                          * reached this commit some other way (where it
  92                          * wasn't uninteresting), in which case we need
  93                          * to mark its parents recursively too..
  94                          */
  95                         if (commit->parents)
  96                                 mark_parents_uninteresting(commit);
  97                 }
  98
  99                 /*
 100                  * A missing commit is ok iff its parent is marked
 101                  * uninteresting.
 102                  *
 103                  * We just mark such a thing parsed, so that when
 104                  * it is popped next time around, we won't be trying
 105                  * to parse it and get an error.
 106                  */
 107                 if (!has_sha1_file(commit->object.sha1))
 108                         commit->object.parsed = 1;
 109                 parents = parents->next;
 110         }
 111 }
 112
 113 static void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
 114 {
 115         add_object(obj, &revs->pending_objects, NULL, name);
 116 }
 117
 118 static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
 119 {
 120         struct object *object;
 121
 122         object = parse_object(sha1);
 123         if (!object)
 124                 die("bad object %s", name);
 125         object->flags |= flags;
 126         return object;
 127 }
 128
 129 static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
 130 {
 131         unsigned long flags = object->flags;
 132
 133         /*
 134          * Tag object? Look what it points to..
 135          */
 136         while (object->type == tag_type) {
 137                 struct tag *tag = (struct tag *) object;
 138                 if (revs->tag_objects && !(flags & UNINTERESTING))
 139                         add_pending_object(revs, object, tag->tag);
 140                 object = parse_object(tag->tagged->sha1);
 141                 if (!object)
 142                         die("bad object %s", sha1_to_hex(tag->tagged->sha1));
 143         }
 144
 145         /*
 146          * Commit object? Just return it, we'll do all the complex
 147          * reachability crud.
 148          */
 149         if (object->type == commit_type) {
 150                 struct commit *commit = (struct commit *)object;
 151                 if (parse_commit(commit) < 0)
 152                         die("unable to parse commit %s", name);
 153                 if (flags & UNINTERESTING) {
 154                         commit->object.flags |= UNINTERESTING;
 155                         mark_parents_uninteresting(commit);
 156                         revs->limited = 1;
 157                 }
 158                 return commit;
 159         }
 160
 161         /*
 162          * Tree object? Either mark it uniniteresting, or add it
 163          * to the list of objects to look at later..
 164          */
 165         if (object->type == tree_type) {
 166                 struct tree *tree = (struct tree *)object;
 167                 if (!revs->tree_objects)
 168                         return NULL;
 169                 if (flags & UNINTERESTING) {
 170                         mark_tree_uninteresting(tree);
 171                         return NULL;
 172                 }
 173                 add_pending_object(revs, object, "");
 174                 return NULL;
 175         }
 176
 177         /*
 178          * Blob object? You know the drill by now..
 179          */
 180         if (object->type == blob_type) {
 181                 struct blob *blob = (struct blob *)object;
 182                 if (!revs->blob_objects)
 183                         return NULL;
 184                 if (flags & UNINTERESTING) {
 185                         mark_blob_uninteresting(blob);
 186                         return NULL;
 187                 }
 188                 add_pending_object(revs, object, "");
 189                 return NULL;
 190         }
 191         die("%s is unknown object", name);
 192 }
 193
 194 static int everybody_uninteresting(struct commit_list *orig)
 195 {
 196         struct commit_list *list = orig;
 197         while (list) {
 198                 struct commit *commit = list->item;
 199                 list = list->next;
 200                 if (commit->object.flags & UNINTERESTING)
 201                         continue;
 202                 return 0;
 203         }
 204         return 1;
 205 }
 206
 207 static int tree_difference = REV_TREE_SAME;
 208
 209 static void file_add_remove(struct diff_options *options,
 210                     int addremove, unsigned mode,
 211                     const unsigned char *sha1,
 212                     const char *base, const char *path)
 213 {
 214         int diff = REV_TREE_DIFFERENT;
 215
 216         /*
 217          * Is it an add of a new file? It means that the old tree
 218          * didn't have it at all, so we will turn "REV_TREE_SAME" ->
 219          * "REV_TREE_NEW", but leave any "REV_TREE_DIFFERENT" alone
 220          * (and if it already was "REV_TREE_NEW", we'll keep it
 221          * "REV_TREE_NEW" of course).
 222          */
 223         if (addremove == '+') {
 224                 diff = tree_difference;
 225                 if (diff != REV_TREE_SAME)
 226                         return;
 227                 diff = REV_TREE_NEW;
 228         }
 229         tree_difference = diff;
 230 }
 231
 232 static void file_change(struct diff_options *options,
 233                  unsigned old_mode, unsigned new_mode,
 234                  const unsigned char *old_sha1,
 235                  const unsigned char *new_sha1,
 236                  const char *base, const char *path)
 237 {
 238         tree_difference = REV_TREE_DIFFERENT;
 239 }
 240
 241 int rev_compare_tree(struct rev_info *revs, struct tree *t1, struct tree *t2)
 242 {
 243         if (!t1)
 244                 return REV_TREE_NEW;
 245         if (!t2)
 246                 return REV_TREE_DIFFERENT;
 247         tree_difference = REV_TREE_SAME;
 248         if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
 249                            &revs->pruning) < 0)
 250                 return REV_TREE_DIFFERENT;
 251         return tree_difference;
 252 }
 253
 254 int rev_same_tree_as_empty(struct rev_info *revs, struct tree *t1)
 255 {
 256         int retval;
 257         void *tree;
 258         struct tree_desc empty, real;
 259
 260         if (!t1)
 261                 return 0;
 262
 263         tree = read_object_with_reference(t1->object.sha1, tree_type, &real.size, NULL);
 264         if (!tree)
 265                 return 0;
 266         real.buf = tree;
 267
 268         empty.buf = "";
 269         empty.size = 0;
 270
 271         tree_difference = 0;
 272         retval = diff_tree(&empty, &real, "", &revs->pruning);
 273         free(tree);
 274
 275         return retval >= 0 && !tree_difference;
 276 }
 277
 278 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 279 {
 280         struct commit_list **pp, *parent;
 281         int tree_changed = 0;
 282
 283         if (!commit->tree)
 284                 return;
 285
 286         if (!commit->parents) {
 287                 if (!rev_same_tree_as_empty(revs, commit->tree))
 288                         commit->object.flags |= TREECHANGE;
 289                 return;
 290         }
 291
 292         pp = &commit->parents;
 293         while ((parent = *pp) != NULL) {
 294                 struct commit *p = parent->item;
 295
 296                 parse_commit(p);
 297                 switch (rev_compare_tree(revs, p->tree, commit->tree)) {
 298                 case REV_TREE_SAME:
 299                         if (p->object.flags & UNINTERESTING) {
 300                                 /* Even if a merge with an uninteresting
 301                                  * side branch brought the entire change
 302                                  * we are interested in, we do not want
 303                                  * to lose the other branches of this
 304                                  * merge, so we just keep going.
 305                                  */
 306                                 pp = &parent->next;
 307                                 continue;
 308                         }
 309                         parent->next = NULL;
 310                         commit->parents = parent;
 311                         return;
 312
 313                 case REV_TREE_NEW:
 314                         if (revs->remove_empty_trees &&
 315                             rev_same_tree_as_empty(revs, p->tree)) {
 316                                 /* We are adding all the specified
 317                                  * paths from this parent, so the
 318                                  * history beyond this parent is not
 319                                  * interesting.  Remove its parents
 320                                  * (they are grandparents for us).
 321                                  * IOW, we pretend this parent is a
 322                                  * "root" commit.
 323                                  */
 324                                 parse_commit(p);
 325                                 p->parents = NULL;
 326                         }
 327                 /* fallthrough */
 328                 case REV_TREE_DIFFERENT:
 329                         tree_changed = 1;
 330                         pp = &parent->next;
 331                         continue;
 332                 }
 333                 die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
 334         }
 335         if (tree_changed)
 336                 commit->object.flags |= TREECHANGE;
 337 }
 338
 339 static void add_parents_to_list(struct rev_info *revs, struct commit *commit, struct commit_list **list)
 340 {
 341         struct commit_list *parent = commit->parents;
 342
 343         if (commit->object.flags & ADDED)
 344                 return;
 345         commit->object.flags |= ADDED;
 346
 347         /*
 348          * If the commit is uninteresting, don't try to
 349          * prune parents - we want the maximal uninteresting
 350          * set.
 351          *
 352          * Normally we haven't parsed the parent
 353          * yet, so we won't have a parent of a parent
 354          * here. However, it may turn out that we've
 355          * reached this commit some other way (where it
 356          * wasn't uninteresting), in which case we need
 357          * to mark its parents recursively too..
 358          */
 359         if (commit->object.flags & UNINTERESTING) {
 360                 while (parent) {
 361                         struct commit *p = parent->item;
 362                         parent = parent->next;
 363                         parse_commit(p);
 364                         p->object.flags |= UNINTERESTING;
 365                         if (p->parents)
 366                                 mark_parents_uninteresting(p);
 367                         if (p->object.flags & SEEN)
 368                                 continue;
 369                         p->object.flags |= SEEN;
 370                         insert_by_date(p, list);
 371                 }
 372                 return;
 373         }
 374
 375         /*
 376          * Ok, the commit wasn't uninteresting. Try to
 377          * simplify the commit history and find the parent
 378          * that has no differences in the path set if one exists.
 379          */
 380         if (revs->prune_fn)
 381                 revs->prune_fn(revs, commit);
 382
 383         if (revs->no_walk)
 384                 return;
 385
 386         parent = commit->parents;
 387         while (parent) {
 388                 struct commit *p = parent->item;
 389
 390                 parent = parent->next;
 391
 392                 parse_commit(p);
 393                 if (p->object.flags & SEEN)
 394                         continue;
 395                 p->object.flags |= SEEN;
 396                 insert_by_date(p, list);
 397         }
 398 }
 399
 400 static void limit_list(struct rev_info *revs)
 401 {
 402         struct commit_list *list = revs->commits;
 403         struct commit_list *newlist = NULL;
 404         struct commit_list **p = &newlist;
 405
 406         while (list) {
 407                 struct commit_list *entry = list;
 408                 struct commit *commit = list->item;
 409                 struct object *obj = &commit->object;
 410
 411                 list = list->next;
 412                 free(entry);
 413
 414                 if (revs->max_age != -1 && (commit->date < revs->max_age))
 415                         obj->flags |= UNINTERESTING;
 416                 if (revs->unpacked && has_sha1_pack(obj->sha1))
 417                         obj->flags |= UNINTERESTING;
 418                 add_parents_to_list(revs, commit, &list);
 419                 if (obj->flags & UNINTERESTING) {
 420                         mark_parents_uninteresting(commit);
 421                         if (everybody_uninteresting(list))
 422                                 break;
 423                         continue;
 424                 }
 425                 if (revs->min_age != -1 && (commit->date > revs->min_age))
 426                         continue;
 427                 p = &commit_list_insert(commit, p)->next;
 428         }
 429         if (revs->boundary) {
 430                 /* mark the ones that are on the result list first */
 431                 for (list = newlist; list; list = list->next) {
 432                         struct commit *commit = list->item;
 433                         commit->object.flags |= TMP_MARK;
 434                 }
 435                 for (list = newlist; list; list = list->next) {
 436                         struct commit *commit = list->item;
 437                         struct object *obj = &commit->object;
 438                         struct commit_list *parent;
 439                         if (obj->flags & UNINTERESTING)
 440                                 continue;
 441                         for (parent = commit->parents;
 442                              parent;
 443                              parent = parent->next) {
 444                                 struct commit *pcommit = parent->item;
 445                                 if (!(pcommit->object.flags & UNINTERESTING))
 446                                         continue;
 447                                 pcommit->object.flags |= BOUNDARY;
 448                                 if (pcommit->object.flags & TMP_MARK)
 449                                         continue;
 450                                 pcommit->object.flags |= TMP_MARK;
 451                                 p = &commit_list_insert(pcommit, p)->next;
 452                         }
 453                 }
 454                 for (list = newlist; list; list = list->next) {
 455                         struct commit *commit = list->item;
 456                         commit->object.flags &= ~TMP_MARK;
 457                 }
 458         }
 459         revs->commits = newlist;
 460 }
 461
 462 static int all_flags;
 463 static struct rev_info *all_revs;
 464
 465 static int handle_one_ref(const char *path, const unsigned char *sha1)
 466 {
 467         struct object *object = get_reference(all_revs, path, sha1, all_flags);
 468         add_pending_object(all_revs, object, "");
 469         return 0;
 470 }
 471
 472 static void handle_all(struct rev_info *revs, unsigned flags)
 473 {
 474         all_revs = revs;
 475         all_flags = flags;
 476         for_each_ref(handle_one_ref);
 477 }
 478
 479 static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
 480 {
 481         unsigned char sha1[20];
 482         struct object *it;
 483         struct commit *commit;
 484         struct commit_list *parents;
 485
 486         if (*arg == '^') {
 487                 flags ^= UNINTERESTING;
 488                 arg++;
 489         }
 490         if (get_sha1(arg, sha1))
 491                 return 0;
 492         while (1) {
 493                 it = get_reference(revs, arg, sha1, 0);
 494                 if (strcmp(it->type, tag_type))
 495                         break;
 496                 memcpy(sha1, ((struct tag*)it)->tagged->sha1, 20);
 497         }
 498         if (strcmp(it->type, commit_type))
 499                 return 0;
 500         commit = (struct commit *)it;
 501         for (parents = commit->parents; parents; parents = parents->next) {
 502                 it = &parents->item->object;
 503                 it->flags |= flags;
 504                 add_pending_object(revs, it, arg);
 505         }
 506         return 1;
 507 }
 508
 509 void init_revisions(struct rev_info *revs)
 510 {
 511         memset(revs, 0, sizeof(*revs));
 512
 513         revs->abbrev = DEFAULT_ABBREV;
 514         revs->ignore_merges = 1;
 515         revs->pruning.recursive = 1;
 516         revs->pruning.add_remove = file_add_remove;
 517         revs->pruning.change = file_change;
 518         revs->lifo = 1;
 519         revs->dense = 1;
 520         revs->prefix = setup_git_directory();
 521         revs->max_age = -1;
 522         revs->min_age = -1;
 523         revs->max_count = -1;
 524
 525         revs->prune_fn = NULL;
 526         revs->prune_data = NULL;
 527
 528         revs->topo_setter = topo_sort_default_setter;
 529         revs->topo_getter = topo_sort_default_getter;
 530
 531         revs->commit_format = CMIT_FMT_DEFAULT;
 532
 533         diff_setup(&revs->diffopt);
 534 }
 535
 536 /*
 537  * Parse revision information, filling in the "rev_info" structure,
 538  * and removing the used arguments from the argument list.
 539  *
 540  * Returns the number of arguments left that weren't recognized
 541  * (which are also moved to the head of the argument list)
 542  */
 543 int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
 544 {
 545         int i, flags, seen_dashdash;
 546         const char **unrecognized = argv + 1;
 547         int left = 1;
 548
 549         /* First, search for "--" */
 550         seen_dashdash = 0;
 551         for (i = 1; i < argc; i++) {
 552                 const char *arg = argv[i];
 553                 if (strcmp(arg, "--"))
 554                         continue;
 555                 argv[i] = NULL;
 556                 argc = i;
 557                 revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
 558                 seen_dashdash = 1;
 559                 break;
 560         }
 561
 562         flags = 0;
 563         for (i = 1; i < argc; i++) {
 564                 struct object *object;
 565                 const char *arg = argv[i];
 566                 unsigned char sha1[20];
 567                 char *dotdot;
 568                 int local_flags;
 569
 570                 if (*arg == '-') {
 571                         int opts;
 572                         if (!strncmp(arg, "--max-count=", 12)) {
 573                                 revs->max_count = atoi(arg + 12);
 574                                 continue;
 575                         }
 576                         /* accept -<digit>, like traditional "head" */
 577                         if ((*arg == '-') && isdigit(arg[1])) {
 578                                 revs->max_count = atoi(arg + 1);
 579                                 continue;
 580                         }
 581                         if (!strcmp(arg, "-n")) {
 582                                 if (argc <= i + 1)
 583                                         die("-n requires an argument");
 584                                 revs->max_count = atoi(argv[++i]);
 585                                 continue;
 586                         }
 587                         if (!strncmp(arg,"-n",2)) {
 588                                 revs->max_count = atoi(arg + 2);
 589                                 continue;
 590                         }
 591                         if (!strncmp(arg, "--max-age=", 10)) {
 592                                 revs->max_age = atoi(arg + 10);
 593                                 continue;
 594                         }
 595                         if (!strncmp(arg, "--since=", 8)) {
 596                                 revs->max_age = approxidate(arg + 8);
 597                                 continue;
 598                         }
 599                         if (!strncmp(arg, "--after=", 8)) {
 600                                 revs->max_age = approxidate(arg + 8);
 601                                 continue;
 602                         }
 603                         if (!strncmp(arg, "--min-age=", 10)) {
 604                                 revs->min_age = atoi(arg + 10);
 605                                 continue;
 606                         }
 607                         if (!strncmp(arg, "--before=", 9)) {
 608                                 revs->min_age = approxidate(arg + 9);
 609                                 continue;
 610                         }
 611                         if (!strncmp(arg, "--until=", 8)) {
 612                                 revs->min_age = approxidate(arg + 8);
 613                                 continue;
 614                         }
 615                         if (!strcmp(arg, "--all")) {
 616                                 handle_all(revs, flags);
 617                                 continue;
 618                         }
 619                         if (!strcmp(arg, "--not")) {
 620                                 flags ^= UNINTERESTING;
 621                                 continue;
 622                         }
 623                         if (!strcmp(arg, "--default")) {
 624                                 if (++i >= argc)
 625                                         die("bad --default argument");
 626                                 def = argv[i];
 627                                 continue;
 628                         }
 629                         if (!strcmp(arg, "--topo-order")) {
 630                                 revs->topo_order = 1;
 631                                 continue;
 632                         }
 633                         if (!strcmp(arg, "--date-order")) {
 634                                 revs->lifo = 0;
 635                                 revs->topo_order = 1;
 636                                 continue;
 637                         }
 638                         if (!strcmp(arg, "--parents")) {
 639                                 revs->parents = 1;
 640                                 continue;
 641                         }
 642                         if (!strcmp(arg, "--dense")) {
 643                                 revs->dense = 1;
 644                                 continue;
 645                         }
 646                         if (!strcmp(arg, "--sparse")) {
 647                                 revs->dense = 0;
 648                                 continue;
 649                         }
 650                         if (!strcmp(arg, "--remove-empty")) {
 651                                 revs->remove_empty_trees = 1;
 652                                 continue;
 653                         }
 654                         if (!strcmp(arg, "--no-merges")) {
 655                                 revs->no_merges = 1;
 656                                 continue;
 657                         }
 658                         if (!strcmp(arg, "--boundary")) {
 659                                 revs->boundary = 1;
 660                                 continue;
 661                         }
 662                         if (!strcmp(arg, "--objects")) {
 663                                 revs->tag_objects = 1;
 664                                 revs->tree_objects = 1;
 665                                 revs->blob_objects = 1;
 666                                 continue;
 667                         }
 668                         if (!strcmp(arg, "--objects-edge")) {
 669                                 revs->tag_objects = 1;
 670                                 revs->tree_objects = 1;
 671                                 revs->blob_objects = 1;
 672                                 revs->edge_hint = 1;
 673                                 continue;
 674                         }
 675                         if (!strcmp(arg, "--unpacked")) {
 676                                 revs->unpacked = 1;
 677                                 continue;
 678                         }
 679                         if (!strcmp(arg, "-r")) {
 680                                 revs->diff = 1;
 681                                 revs->diffopt.recursive = 1;
 682                                 continue;
 683                         }
 684                         if (!strcmp(arg, "-t")) {
 685                                 revs->diff = 1;
 686                                 revs->diffopt.recursive = 1;
 687                                 revs->diffopt.tree_in_recursive = 1;
 688                                 continue;
 689                         }
 690                         if (!strcmp(arg, "-m")) {
 691                                 revs->ignore_merges = 0;
 692                                 continue;
 693                         }
 694                         if (!strcmp(arg, "-c")) {
 695                                 revs->diff = 1;
 696                                 revs->dense_combined_merges = 0;
 697                                 revs->combine_merges = 1;
 698                                 continue;
 699                         }
 700                         if (!strcmp(arg, "--cc")) {
 701                                 revs->diff = 1;
 702                                 revs->dense_combined_merges = 1;
 703                                 revs->combine_merges = 1;
 704                                 continue;
 705                         }
 706                         if (!strcmp(arg, "-v")) {
 707                                 revs->verbose_header = 1;
 708                                 continue;
 709                         }
 710                         if (!strncmp(arg, "--pretty", 8)) {
 711                                 revs->verbose_header = 1;
 712                                 revs->commit_format = get_commit_format(arg+8);
 713                                 continue;
 714                         }
 715                         if (!strcmp(arg, "--root")) {
 716                                 revs->show_root_diff = 1;
 717                                 continue;
 718                         }
 719                         if (!strcmp(arg, "--no-commit-id")) {
 720                                 revs->no_commit_id = 1;
 721                                 continue;
 722                         }
 723                         if (!strcmp(arg, "--always")) {
 724                                 revs->always_show_header = 1;
 725                                 continue;
 726                         }
 727                         if (!strcmp(arg, "--no-abbrev")) {
 728                                 revs->abbrev = 0;
 729                                 continue;
 730                         }
 731                         if (!strcmp(arg, "--abbrev")) {
 732                                 revs->abbrev = DEFAULT_ABBREV;
 733                                 continue;
 734                         }
 735                         if (!strncmp(arg, "--abbrev=", 9)) {
 736                                 revs->abbrev = strtoul(arg + 9, NULL, 10);
 737                                 if (revs->abbrev < MINIMUM_ABBREV)
 738                                         revs->abbrev = MINIMUM_ABBREV;
 739                                 else if (revs->abbrev > 40)
 740                                         revs->abbrev = 40;
 741                                 continue;
 742                         }
 743                         if (!strcmp(arg, "--abbrev-commit")) {
 744                                 revs->abbrev_commit = 1;
 745                                 continue;
 746                         }
 747                         if (!strcmp(arg, "--full-diff")) {
 748                                 revs->diff = 1;
 749                                 revs->full_diff = 1;
 750                                 continue;
 751                         }
 752                         opts = diff_opt_parse(&revs->diffopt, argv+i, argc-i);
 753                         if (opts > 0) {
 754                                 revs->diff = 1;
 755                                 i += opts - 1;
 756                                 continue;
 757                         }
 758                         *unrecognized++ = arg;
 759                         left++;
 760                         continue;
 761                 }
 762                 dotdot = strstr(arg, "..");
 763                 if (dotdot) {
 764                         unsigned char from_sha1[20];
 765                         const char *next = dotdot + 2;
 766                         const char *this = arg;
 767                         *dotdot = 0;
 768                         if (!*next)
 769                                 next = "HEAD";
 770                         if (dotdot == arg)
 771                                 this = "HEAD";
 772                         if (!get_sha1(this, from_sha1) &&
 773                             !get_sha1(next, sha1)) {
 774                                 struct object *exclude;
 775                                 struct object *include;
 776
 777                                 exclude = get_reference(revs, this, from_sha1, flags ^ UNINTERESTING);
 778                                 include = get_reference(revs, next, sha1, flags);
 779                                 if (!exclude || !include)
 780                                         die("Invalid revision range %s..%s", arg, next);
 781
 782                                 if (!seen_dashdash) {
 783                                         *dotdot = '.';
 784                                         verify_non_filename(revs->prefix, arg);
 785                                 }
 786                                 add_pending_object(revs, exclude, this);
 787                                 add_pending_object(revs, include, next);
 788                                 continue;
 789                         }
 790                         *dotdot = '.';
 791                 }
 792                 dotdot = strstr(arg, "^@");
 793                 if (dotdot && !dotdot[2]) {
 794                         *dotdot = 0;
 795                         if (add_parents_only(revs, arg, flags))
 796                                 continue;
 797                         *dotdot = '^';
 798                 }
 799                 local_flags = 0;
 800                 if (*arg == '^') {
 801                         local_flags = UNINTERESTING;
 802                         arg++;
 803                 }
 804                 if (get_sha1(arg, sha1)) {
 805                         int j;
 806
 807                         if (seen_dashdash || local_flags)
 808                                 die("bad revision '%s'", arg);
 809
 810                         /* If we didn't have a "--":
 811                          * (1) all filenames must exist;
 812                          * (2) all rev-args must not be interpretable
 813                          *     as a valid filename.
 814                          * but the latter we have checked in the main loop.
 815                          */
 816                         for (j = i; j < argc; j++)
 817                                 verify_filename(revs->prefix, argv[j]);
 818
 819                         revs->prune_data = get_pathspec(revs->prefix, argv + i);
 820                         break;
 821                 }
 822                 if (!seen_dashdash)
 823                         verify_non_filename(revs->prefix, arg);
 824                 object = get_reference(revs, arg, sha1, flags ^ local_flags);
 825                 add_pending_object(revs, object, arg);
 826         }
 827         if (def && !revs->pending_objects) {
 828                 unsigned char sha1[20];
 829                 struct object *object;
 830                 if (get_sha1(def, sha1))
 831                         die("bad default revision '%s'", def);
 832                 object = get_reference(revs, def, sha1, 0);
 833                 add_pending_object(revs, object, def);
 834         }
 835
 836         if (revs->topo_order || revs->unpacked)
 837                 revs->limited = 1;
 838
 839         if (revs->prune_data) {
 840                 diff_tree_setup_paths(revs->prune_data, &revs->pruning);
 841                 revs->prune_fn = try_to_simplify_commit;
 842                 if (!revs->full_diff)
 843                         diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
 844         }
 845         if (revs->combine_merges) {
 846                 revs->ignore_merges = 0;
 847                 if (revs->dense_combined_merges &&
 848                     (revs->diffopt.output_format != DIFF_FORMAT_DIFFSTAT))
 849                         revs->diffopt.output_format = DIFF_FORMAT_PATCH;
 850         }
 851         revs->diffopt.abbrev = revs->abbrev;
 852         diff_setup_done(&revs->diffopt);
 853
 854         return left;
 855 }
 856
 857 void prepare_revision_walk(struct rev_info *revs)
 858 {
 859         struct object_list *list;
 860
 861         list = revs->pending_objects;
 862         revs->pending_objects = NULL;
 863         while (list) {
 864                 struct commit *commit = handle_commit(revs, list->item, list->name);
 865                 if (commit) {
 866                         if (!(commit->object.flags & SEEN)) {
 867                                 commit->object.flags |= SEEN;
 868                                 insert_by_date(commit, &revs->commits);
 869                         }
 870                 }
 871                 list = list->next;
 872         }
 873
 874         if (revs->no_walk)
 875                 return;
 876         if (revs->limited)
 877                 limit_list(revs);
 878         if (revs->topo_order)
 879                 sort_in_topological_order_fn(&revs->commits, revs->lifo,
 880                                              revs->topo_setter,
 881                                              revs->topo_getter);
 882 }
 883
 884 static int rewrite_one(struct rev_info *revs, struct commit **pp)
 885 {
 886         for (;;) {
 887                 struct commit *p = *pp;
 888                 if (!revs->limited)
 889                         add_parents_to_list(revs, p, &revs->commits);
 890                 if (p->object.flags & (TREECHANGE | UNINTERESTING))
 891                         return 0;
 892                 if (!p->parents)
 893                         return -1;
 894                 *pp = p->parents->item;
 895         }
 896 }
 897
 898 static void rewrite_parents(struct rev_info *revs, struct commit *commit)
 899 {
 900         struct commit_list **pp = &commit->parents;
 901         while (*pp) {
 902                 struct commit_list *parent = *pp;
 903                 if (rewrite_one(revs, &parent->item) < 0) {
 904                         *pp = parent->next;
 905                         continue;
 906                 }
 907                 pp = &parent->next;
 908         }
 909 }
 910
 911 static void mark_boundary_to_show(struct commit *commit)
 912 {
 913         struct commit_list *p = commit->parents;
 914         while (p) {
 915                 commit = p->item;
 916                 p = p->next;
 917                 if (commit->object.flags & BOUNDARY)
 918                         commit->object.flags |= BOUNDARY_SHOW;
 919         }
 920 }
 921
 922 struct commit *get_revision(struct rev_info *revs)
 923 {
 924         struct commit_list *list = revs->commits;
 925
 926         if (!list)
 927                 return NULL;
 928
 929         /* Check the max_count ... */
 930         switch (revs->max_count) {
 931         case -1:
 932                 break;
 933         case 0:
 934                 return NULL;
 935         default:
 936                 revs->max_count--;
 937         }
 938
 939         do {
 940                 struct commit *commit = revs->commits->item;
 941
 942                 revs->commits = revs->commits->next;
 943
 944                 /*
 945                  * If we haven't done the list limiting, we need to look at
 946                  * the parents here. We also need to do the date-based limiting
 947                  * that we'd otherwise have done in limit_list().
 948                  */
 949                 if (!revs->limited) {
 950                         if ((revs->unpacked &&
 951                              has_sha1_pack(commit->object.sha1)) ||
 952                             (revs->max_age != -1 &&
 953                              (commit->date < revs->max_age)))
 954                                 continue;
 955                         add_parents_to_list(revs, commit, &revs->commits);
 956                 }
 957                 if (commit->object.flags & SHOWN)
 958                         continue;
 959
 960                 /* We want to show boundary commits only when their
 961                  * children are shown.  When path-limiter is in effect,
 962                  * rewrite_parents() drops some commits from getting shown,
 963                  * and there is no point showing boundary parents that
 964                  * are not shown.  After rewrite_parents() rewrites the
 965                  * parents of a commit that is shown, we mark the boundary
 966                  * parents with BOUNDARY_SHOW.
 967                  */
 968                 if (commit->object.flags & BOUNDARY_SHOW) {
 969                         commit->object.flags |= SHOWN;
 970                         return commit;
 971                 }
 972                 if (commit->object.flags & UNINTERESTING)
 973                         continue;
 974                 if (revs->min_age != -1 && (commit->date > revs->min_age))
 975                         continue;
 976                 if (revs->no_merges &&
 977                     commit->parents && commit->parents->next)
 978                         continue;
 979                 if (revs->prune_fn && revs->dense) {
 980                         if (!(commit->object.flags & TREECHANGE))
 981                                 continue;
 982                         if (revs->parents)
 983                                 rewrite_parents(revs, commit);
 984                 }
 985                 if (revs->boundary)
 986                         mark_boundary_to_show(commit);
 987                 commit->object.flags |= SHOWN;
 988                 return commit;
 989         } while (revs->commits);
 990         return NULL;
 991 }