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 tree_desc desc;
  57         struct name_entry entry;
  58         struct object *obj = &tree->object;
  59
  60         if (obj->flags & UNINTERESTING)
  61                 return;
  62         obj->flags |= UNINTERESTING;
  63         if (!has_sha1_file(obj->sha1))
  64                 return;
  65         if (parse_tree(tree) < 0)
  66                 die("bad tree %s", sha1_to_hex(obj->sha1));
  67
  68         desc.buf = tree->buffer;
  69         desc.size = tree->size;
  70         while (tree_entry(&desc, &entry)) {
  71                 if (S_ISDIR(entry.mode))
  72                         mark_tree_uninteresting(lookup_tree(entry.sha1));
  73                 else
  74                         mark_blob_uninteresting(lookup_blob(entry.sha1));
  75         }
  76
  77         /*
  78          * We don't care about the tree any more
  79          * after it has been marked uninteresting.
  80          */
  81         free(tree->buffer);
  82         tree->buffer = NULL;
  83 }
  84
  85 void mark_parents_uninteresting(struct commit *commit)
  86 {
  87         struct commit_list *parents = commit->parents;
  88
  89         while (parents) {
  90                 struct commit *commit = parents->item;
  91                 if (!(commit->object.flags & UNINTERESTING)) {
  92                         commit->object.flags |= UNINTERESTING;
  93
  94                         /*
  95                          * Normally we haven't parsed the parent
  96                          * yet, so we won't have a parent of a parent
  97                          * here. However, it may turn out that we've
  98                          * reached this commit some other way (where it
  99                          * wasn't uninteresting), in which case we need
 100                          * to mark its parents recursively too..
 101                          */
 102                         if (commit->parents)
 103                                 mark_parents_uninteresting(commit);
 104                 }
 105
 106                 /*
 107                  * A missing commit is ok iff its parent is marked
 108                  * uninteresting.
 109                  *
 110                  * We just mark such a thing parsed, so that when
 111                  * it is popped next time around, we won't be trying
 112                  * to parse it and get an error.
 113                  */
 114                 if (!has_sha1_file(commit->object.sha1))
 115                         commit->object.parsed = 1;
 116                 parents = parents->next;
 117         }
 118 }
 119
 120 static void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
 121 {
 122         add_object(obj, &revs->pending_objects, NULL, 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 == tag_type) {
 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 == commit_type) {
 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 == tree_type) {
 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 == blob_type) {
 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;
 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                         if (!revs->simplify_history || (p->object.flags & UNINTERESTING)) {
 307                                 /* Even if a merge with an uninteresting
 308                                  * side branch brought the entire change
 309                                  * we are interested in, we do not want
 310                                  * to lose the other branches of this
 311                                  * merge, so we just keep going.
 312                                  */
 313                                 pp = &parent->next;
 314                                 continue;
 315                         }
 316                         parent->next = NULL;
 317                         commit->parents = parent;
 318                         return;
 319
 320                 case REV_TREE_NEW:
 321                         if (revs->remove_empty_trees &&
 322                             rev_same_tree_as_empty(revs, p->tree)) {
 323                                 /* We are adding all the specified
 324                                  * paths from this parent, so the
 325                                  * history beyond this parent is not
 326                                  * interesting.  Remove its parents
 327                                  * (they are grandparents for us).
 328                                  * IOW, we pretend this parent is a
 329                                  * "root" commit.
 330                                  */
 331                                 parse_commit(p);
 332                                 p->parents = NULL;
 333                         }
 334                 /* fallthrough */
 335                 case REV_TREE_DIFFERENT:
 336                         tree_changed = 1;
 337                         pp = &parent->next;
 338                         continue;
 339                 }
 340                 die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
 341         }
 342         if (tree_changed)
 343                 commit->object.flags |= TREECHANGE;
 344 }
 345
 346 static void add_parents_to_list(struct rev_info *revs, struct commit *commit, struct commit_list **list)
 347 {
 348         struct commit_list *parent = commit->parents;
 349
 350         if (commit->object.flags & ADDED)
 351                 return;
 352         commit->object.flags |= ADDED;
 353
 354         /*
 355          * If the commit is uninteresting, don't try to
 356          * prune parents - we want the maximal uninteresting
 357          * set.
 358          *
 359          * Normally we haven't parsed the parent
 360          * yet, so we won't have a parent of a parent
 361          * here. However, it may turn out that we've
 362          * reached this commit some other way (where it
 363          * wasn't uninteresting), in which case we need
 364          * to mark its parents recursively too..
 365          */
 366         if (commit->object.flags & UNINTERESTING) {
 367                 while (parent) {
 368                         struct commit *p = parent->item;
 369                         parent = parent->next;
 370                         parse_commit(p);
 371                         p->object.flags |= UNINTERESTING;
 372                         if (p->parents)
 373                                 mark_parents_uninteresting(p);
 374                         if (p->object.flags & SEEN)
 375                                 continue;
 376                         p->object.flags |= SEEN;
 377                         insert_by_date(p, list);
 378                 }
 379                 return;
 380         }
 381
 382         /*
 383          * Ok, the commit wasn't uninteresting. Try to
 384          * simplify the commit history and find the parent
 385          * that has no differences in the path set if one exists.
 386          */
 387         if (revs->prune_fn)
 388                 revs->prune_fn(revs, commit);
 389
 390         if (revs->no_walk)
 391                 return;
 392
 393         parent = commit->parents;
 394         while (parent) {
 395                 struct commit *p = parent->item;
 396
 397                 parent = parent->next;
 398
 399                 parse_commit(p);
 400                 if (p->object.flags & SEEN)
 401                         continue;
 402                 p->object.flags |= SEEN;
 403                 insert_by_date(p, list);
 404         }
 405 }
 406
 407 static void limit_list(struct rev_info *revs)
 408 {
 409         struct commit_list *list = revs->commits;
 410         struct commit_list *newlist = NULL;
 411         struct commit_list **p = &newlist;
 412
 413         while (list) {
 414                 struct commit_list *entry = list;
 415                 struct commit *commit = list->item;
 416                 struct object *obj = &commit->object;
 417
 418                 list = list->next;
 419                 free(entry);
 420
 421                 if (revs->max_age != -1 && (commit->date < revs->max_age))
 422                         obj->flags |= UNINTERESTING;
 423                 if (revs->unpacked && has_sha1_pack(obj->sha1))
 424                         obj->flags |= UNINTERESTING;
 425                 add_parents_to_list(revs, commit, &list);
 426                 if (obj->flags & UNINTERESTING) {
 427                         mark_parents_uninteresting(commit);
 428                         if (everybody_uninteresting(list))
 429                                 break;
 430                         continue;
 431                 }
 432                 if (revs->min_age != -1 && (commit->date > revs->min_age))
 433                         continue;
 434                 p = &commit_list_insert(commit, p)->next;
 435         }
 436         if (revs->boundary) {
 437                 /* mark the ones that are on the result list first */
 438                 for (list = newlist; list; list = list->next) {
 439                         struct commit *commit = list->item;
 440                         commit->object.flags |= TMP_MARK;
 441                 }
 442                 for (list = newlist; list; list = list->next) {
 443                         struct commit *commit = list->item;
 444                         struct object *obj = &commit->object;
 445                         struct commit_list *parent;
 446                         if (obj->flags & UNINTERESTING)
 447                                 continue;
 448                         for (parent = commit->parents;
 449                              parent;
 450                              parent = parent->next) {
 451                                 struct commit *pcommit = parent->item;
 452                                 if (!(pcommit->object.flags & UNINTERESTING))
 453                                         continue;
 454                                 pcommit->object.flags |= BOUNDARY;
 455                                 if (pcommit->object.flags & TMP_MARK)
 456                                         continue;
 457                                 pcommit->object.flags |= TMP_MARK;
 458                                 p = &commit_list_insert(pcommit, p)->next;
 459                         }
 460                 }
 461                 for (list = newlist; list; list = list->next) {
 462                         struct commit *commit = list->item;
 463                         commit->object.flags &= ~TMP_MARK;
 464                 }
 465         }
 466         revs->commits = newlist;
 467 }
 468
 469 static int all_flags;
 470 static struct rev_info *all_revs;
 471
 472 static int handle_one_ref(const char *path, const unsigned char *sha1)
 473 {
 474         struct object *object = get_reference(all_revs, path, sha1, all_flags);
 475         add_pending_object(all_revs, object, "");
 476         return 0;
 477 }
 478
 479 static void handle_all(struct rev_info *revs, unsigned flags)
 480 {
 481         all_revs = revs;
 482         all_flags = flags;
 483         for_each_ref(handle_one_ref);
 484 }
 485
 486 static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
 487 {
 488         unsigned char sha1[20];
 489         struct object *it;
 490         struct commit *commit;
 491         struct commit_list *parents;
 492
 493         if (*arg == '^') {
 494                 flags ^= UNINTERESTING;
 495                 arg++;
 496         }
 497         if (get_sha1(arg, sha1))
 498                 return 0;
 499         while (1) {
 500                 it = get_reference(revs, arg, sha1, 0);
 501                 if (strcmp(it->type, tag_type))
 502                         break;
 503                 memcpy(sha1, ((struct tag*)it)->tagged->sha1, 20);
 504         }
 505         if (strcmp(it->type, commit_type))
 506                 return 0;
 507         commit = (struct commit *)it;
 508         for (parents = commit->parents; parents; parents = parents->next) {
 509                 it = &parents->item->object;
 510                 it->flags |= flags;
 511                 add_pending_object(revs, it, arg);
 512         }
 513         return 1;
 514 }
 515
 516 void init_revisions(struct rev_info *revs)
 517 {
 518         memset(revs, 0, sizeof(*revs));
 519
 520         revs->abbrev = DEFAULT_ABBREV;
 521         revs->ignore_merges = 1;
 522         revs->simplify_history = 1;
 523         revs->pruning.recursive = 1;
 524         revs->pruning.add_remove = file_add_remove;
 525         revs->pruning.change = file_change;
 526         revs->lifo = 1;
 527         revs->dense = 1;
 528         revs->prefix = setup_git_directory();
 529         revs->max_age = -1;
 530         revs->min_age = -1;
 531         revs->max_count = -1;
 532
 533         revs->prune_fn = NULL;
 534         revs->prune_data = NULL;
 535
 536         revs->topo_setter = topo_sort_default_setter;
 537         revs->topo_getter = topo_sort_default_getter;
 538
 539         revs->commit_format = CMIT_FMT_DEFAULT;
 540
 541         diff_setup(&revs->diffopt);
 542 }
 543
 544 /*
 545  * Parse revision information, filling in the "rev_info" structure,
 546  * and removing the used arguments from the argument list.
 547  *
 548  * Returns the number of arguments left that weren't recognized
 549  * (which are also moved to the head of the argument list)
 550  */
 551 int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
 552 {
 553         int i, flags, seen_dashdash;
 554         const char **unrecognized = argv + 1;
 555         int left = 1;
 556
 557         /* First, search for "--" */
 558         seen_dashdash = 0;
 559         for (i = 1; i < argc; i++) {
 560                 const char *arg = argv[i];
 561                 if (strcmp(arg, "--"))
 562                         continue;
 563                 argv[i] = NULL;
 564                 argc = i;
 565                 revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
 566                 seen_dashdash = 1;
 567                 break;
 568         }
 569
 570         flags = 0;
 571         for (i = 1; i < argc; i++) {
 572                 struct object *object;
 573                 const char *arg = argv[i];
 574                 unsigned char sha1[20];
 575                 char *dotdot;
 576                 int local_flags;
 577
 578                 if (*arg == '-') {
 579                         int opts;
 580                         if (!strncmp(arg, "--max-count=", 12)) {
 581                                 revs->max_count = atoi(arg + 12);
 582                                 continue;
 583                         }
 584                         /* accept -<digit>, like traditional "head" */
 585                         if ((*arg == '-') && isdigit(arg[1])) {
 586                                 revs->max_count = atoi(arg + 1);
 587                                 continue;
 588                         }
 589                         if (!strcmp(arg, "-n")) {
 590                                 if (argc <= i + 1)
 591                                         die("-n requires an argument");
 592                                 revs->max_count = atoi(argv[++i]);
 593                                 continue;
 594                         }
 595                         if (!strncmp(arg,"-n",2)) {
 596                                 revs->max_count = atoi(arg + 2);
 597                                 continue;
 598                         }
 599                         if (!strncmp(arg, "--max-age=", 10)) {
 600                                 revs->max_age = atoi(arg + 10);
 601                                 continue;
 602                         }
 603                         if (!strncmp(arg, "--since=", 8)) {
 604                                 revs->max_age = approxidate(arg + 8);
 605                                 continue;
 606                         }
 607                         if (!strncmp(arg, "--after=", 8)) {
 608                                 revs->max_age = approxidate(arg + 8);
 609                                 continue;
 610                         }
 611                         if (!strncmp(arg, "--min-age=", 10)) {
 612                                 revs->min_age = atoi(arg + 10);
 613                                 continue;
 614                         }
 615                         if (!strncmp(arg, "--before=", 9)) {
 616                                 revs->min_age = approxidate(arg + 9);
 617                                 continue;
 618                         }
 619                         if (!strncmp(arg, "--until=", 8)) {
 620                                 revs->min_age = approxidate(arg + 8);
 621                                 continue;
 622                         }
 623                         if (!strcmp(arg, "--all")) {
 624                                 handle_all(revs, flags);
 625                                 continue;
 626                         }
 627                         if (!strcmp(arg, "--not")) {
 628                                 flags ^= UNINTERESTING;
 629                                 continue;
 630                         }
 631                         if (!strcmp(arg, "--default")) {
 632                                 if (++i >= argc)
 633                                         die("bad --default argument");
 634                                 def = argv[i];
 635                                 continue;
 636                         }
 637                         if (!strcmp(arg, "--topo-order")) {
 638                                 revs->topo_order = 1;
 639                                 continue;
 640                         }
 641                         if (!strcmp(arg, "--date-order")) {
 642                                 revs->lifo = 0;
 643                                 revs->topo_order = 1;
 644                                 continue;
 645                         }
 646                         if (!strcmp(arg, "--parents")) {
 647                                 revs->parents = 1;
 648                                 continue;
 649                         }
 650                         if (!strcmp(arg, "--dense")) {
 651                                 revs->dense = 1;
 652                                 continue;
 653                         }
 654                         if (!strcmp(arg, "--sparse")) {
 655                                 revs->dense = 0;
 656                                 continue;
 657                         }
 658                         if (!strcmp(arg, "--remove-empty")) {
 659                                 revs->remove_empty_trees = 1;
 660                                 continue;
 661                         }
 662                         if (!strcmp(arg, "--no-merges")) {
 663                                 revs->no_merges = 1;
 664                                 continue;
 665                         }
 666                         if (!strcmp(arg, "--boundary")) {
 667                                 revs->boundary = 1;
 668                                 continue;
 669                         }
 670                         if (!strcmp(arg, "--objects")) {
 671                                 revs->tag_objects = 1;
 672                                 revs->tree_objects = 1;
 673                                 revs->blob_objects = 1;
 674                                 continue;
 675                         }
 676                         if (!strcmp(arg, "--objects-edge")) {
 677                                 revs->tag_objects = 1;
 678                                 revs->tree_objects = 1;
 679                                 revs->blob_objects = 1;
 680                                 revs->edge_hint = 1;
 681                                 continue;
 682                         }
 683                         if (!strcmp(arg, "--unpacked")) {
 684                                 revs->unpacked = 1;
 685                                 continue;
 686                         }
 687                         if (!strcmp(arg, "-r")) {
 688                                 revs->diff = 1;
 689                                 revs->diffopt.recursive = 1;
 690                                 continue;
 691                         }
 692                         if (!strcmp(arg, "-t")) {
 693                                 revs->diff = 1;
 694                                 revs->diffopt.recursive = 1;
 695                                 revs->diffopt.tree_in_recursive = 1;
 696                                 continue;
 697                         }
 698                         if (!strcmp(arg, "-m")) {
 699                                 revs->ignore_merges = 0;
 700                                 continue;
 701                         }
 702                         if (!strcmp(arg, "-c")) {
 703                                 revs->diff = 1;
 704                                 revs->dense_combined_merges = 0;
 705                                 revs->combine_merges = 1;
 706                                 continue;
 707                         }
 708                         if (!strcmp(arg, "--cc")) {
 709                                 revs->diff = 1;
 710                                 revs->dense_combined_merges = 1;
 711                                 revs->combine_merges = 1;
 712                                 continue;
 713                         }
 714                         if (!strcmp(arg, "-v")) {
 715                                 revs->verbose_header = 1;
 716                                 continue;
 717                         }
 718                         if (!strncmp(arg, "--pretty", 8)) {
 719                                 revs->verbose_header = 1;
 720                                 revs->commit_format = get_commit_format(arg+8);
 721                                 continue;
 722                         }
 723                         if (!strcmp(arg, "--root")) {
 724                                 revs->show_root_diff = 1;
 725                                 continue;
 726                         }
 727                         if (!strcmp(arg, "--no-commit-id")) {
 728                                 revs->no_commit_id = 1;
 729                                 continue;
 730                         }
 731                         if (!strcmp(arg, "--always")) {
 732                                 revs->always_show_header = 1;
 733                                 continue;
 734                         }
 735                         if (!strcmp(arg, "--no-abbrev")) {
 736                                 revs->abbrev = 0;
 737                                 continue;
 738                         }
 739                         if (!strcmp(arg, "--abbrev")) {
 740                                 revs->abbrev = DEFAULT_ABBREV;
 741                                 continue;
 742                         }
 743                         if (!strncmp(arg, "--abbrev=", 9)) {
 744                                 revs->abbrev = strtoul(arg + 9, NULL, 10);
 745                                 if (revs->abbrev < MINIMUM_ABBREV)
 746                                         revs->abbrev = MINIMUM_ABBREV;
 747                                 else if (revs->abbrev > 40)
 748                                         revs->abbrev = 40;
 749                                 continue;
 750                         }
 751                         if (!strcmp(arg, "--abbrev-commit")) {
 752                                 revs->abbrev_commit = 1;
 753                                 continue;
 754                         }
 755                         if (!strcmp(arg, "--full-diff")) {
 756                                 revs->diff = 1;
 757                                 revs->full_diff = 1;
 758                                 continue;
 759                         }
 760                         if (!strcmp(arg, "--full-history")) {
 761                                 revs->simplify_history = 0;
 762                                 continue;
 763                         }
 764                         opts = diff_opt_parse(&revs->diffopt, argv+i, argc-i);
 765                         if (opts > 0) {
 766                                 revs->diff = 1;
 767                                 i += opts - 1;
 768                                 continue;
 769                         }
 770                         *unrecognized++ = arg;
 771                         left++;
 772                         continue;
 773                 }
 774                 dotdot = strstr(arg, "..");
 775                 if (dotdot) {
 776                         unsigned char from_sha1[20];
 777                         const char *next = dotdot + 2;
 778                         const char *this = arg;
 779                         *dotdot = 0;
 780                         if (!*next)
 781                                 next = "HEAD";
 782                         if (dotdot == arg)
 783                                 this = "HEAD";
 784                         if (!get_sha1(this, from_sha1) &&
 785                             !get_sha1(next, sha1)) {
 786                                 struct object *exclude;
 787                                 struct object *include;
 788
 789                                 exclude = get_reference(revs, this, from_sha1, flags ^ UNINTERESTING);
 790                                 include = get_reference(revs, next, sha1, flags);
 791                                 if (!exclude || !include)
 792                                         die("Invalid revision range %s..%s", arg, next);
 793
 794                                 if (!seen_dashdash) {
 795                                         *dotdot = '.';
 796                                         verify_non_filename(revs->prefix, arg);
 797                                 }
 798                                 add_pending_object(revs, exclude, this);
 799                                 add_pending_object(revs, include, next);
 800                                 continue;
 801                         }
 802                         *dotdot = '.';
 803                 }
 804                 dotdot = strstr(arg, "^@");
 805                 if (dotdot && !dotdot[2]) {
 806                         *dotdot = 0;
 807                         if (add_parents_only(revs, arg, flags))
 808                                 continue;
 809                         *dotdot = '^';
 810                 }
 811                 local_flags = 0;
 812                 if (*arg == '^') {
 813                         local_flags = UNINTERESTING;
 814                         arg++;
 815                 }
 816                 if (get_sha1(arg, sha1)) {
 817                         int j;
 818
 819                         if (seen_dashdash || local_flags)
 820                                 die("bad revision '%s'", arg);
 821
 822                         /* If we didn't have a "--":
 823                          * (1) all filenames must exist;
 824                          * (2) all rev-args must not be interpretable
 825                          *     as a valid filename.
 826                          * but the latter we have checked in the main loop.
 827                          */
 828                         for (j = i; j < argc; j++)
 829                                 verify_filename(revs->prefix, argv[j]);
 830
 831                         revs->prune_data = get_pathspec(revs->prefix, argv + i);
 832                         break;
 833                 }
 834                 if (!seen_dashdash)
 835                         verify_non_filename(revs->prefix, arg);
 836                 object = get_reference(revs, arg, sha1, flags ^ local_flags);
 837                 add_pending_object(revs, object, arg);
 838         }
 839         if (def && !revs->pending_objects) {
 840                 unsigned char sha1[20];
 841                 struct object *object;
 842                 if (get_sha1(def, sha1))
 843                         die("bad default revision '%s'", def);
 844                 object = get_reference(revs, def, sha1, 0);
 845                 add_pending_object(revs, object, def);
 846         }
 847
 848         if (revs->topo_order || revs->unpacked)
 849                 revs->limited = 1;
 850
 851         if (revs->prune_data) {
 852                 diff_tree_setup_paths(revs->prune_data, &revs->pruning);
 853                 revs->prune_fn = try_to_simplify_commit;
 854                 if (!revs->full_diff)
 855                         diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
 856         }
 857         if (revs->combine_merges) {
 858                 revs->ignore_merges = 0;
 859                 if (revs->dense_combined_merges &&
 860                     (revs->diffopt.output_format != DIFF_FORMAT_DIFFSTAT))
 861                         revs->diffopt.output_format = DIFF_FORMAT_PATCH;
 862         }
 863         revs->diffopt.abbrev = revs->abbrev;
 864         diff_setup_done(&revs->diffopt);
 865
 866         return left;
 867 }
 868
 869 void prepare_revision_walk(struct rev_info *revs)
 870 {
 871         struct object_list *list;
 872
 873         list = revs->pending_objects;
 874         revs->pending_objects = NULL;
 875         while (list) {
 876                 struct commit *commit = handle_commit(revs, list->item, list->name);
 877                 if (commit) {
 878                         if (!(commit->object.flags & SEEN)) {
 879                                 commit->object.flags |= SEEN;
 880                                 insert_by_date(commit, &revs->commits);
 881                         }
 882                 }
 883                 list = list->next;
 884         }
 885
 886         if (revs->no_walk)
 887                 return;
 888         if (revs->limited)
 889                 limit_list(revs);
 890         if (revs->topo_order)
 891                 sort_in_topological_order_fn(&revs->commits, revs->lifo,
 892                                              revs->topo_setter,
 893                                              revs->topo_getter);
 894 }
 895
 896 static int rewrite_one(struct rev_info *revs, struct commit **pp)
 897 {
 898         for (;;) {
 899                 struct commit *p = *pp;
 900                 if (!revs->limited)
 901                         add_parents_to_list(revs, p, &revs->commits);
 902                 if (p->object.flags & (TREECHANGE | UNINTERESTING))
 903                         return 0;
 904                 if (!p->parents)
 905                         return -1;
 906                 *pp = p->parents->item;
 907         }
 908 }
 909
 910 static void rewrite_parents(struct rev_info *revs, struct commit *commit)
 911 {
 912         struct commit_list **pp = &commit->parents;
 913         while (*pp) {
 914                 struct commit_list *parent = *pp;
 915                 if (rewrite_one(revs, &parent->item) < 0) {
 916                         *pp = parent->next;
 917                         continue;
 918                 }
 919                 pp = &parent->next;
 920         }
 921 }
 922
 923 static void mark_boundary_to_show(struct commit *commit)
 924 {
 925         struct commit_list *p = commit->parents;
 926         while (p) {
 927                 commit = p->item;
 928                 p = p->next;
 929                 if (commit->object.flags & BOUNDARY)
 930                         commit->object.flags |= BOUNDARY_SHOW;
 931         }
 932 }
 933
 934 struct commit *get_revision(struct rev_info *revs)
 935 {
 936         struct commit_list *list = revs->commits;
 937
 938         if (!list)
 939                 return NULL;
 940
 941         /* Check the max_count ... */
 942         switch (revs->max_count) {
 943         case -1:
 944                 break;
 945         case 0:
 946                 return NULL;
 947         default:
 948                 revs->max_count--;
 949         }
 950
 951         do {
 952                 struct commit *commit = revs->commits->item;
 953
 954                 revs->commits = revs->commits->next;
 955
 956                 /*
 957                  * If we haven't done the list limiting, we need to look at
 958                  * the parents here. We also need to do the date-based limiting
 959                  * that we'd otherwise have done in limit_list().
 960                  */
 961                 if (!revs->limited) {
 962                         if ((revs->unpacked &&
 963                              has_sha1_pack(commit->object.sha1)) ||
 964                             (revs->max_age != -1 &&
 965                              (commit->date < revs->max_age)))
 966                                 continue;
 967                         add_parents_to_list(revs, commit, &revs->commits);
 968                 }
 969                 if (commit->object.flags & SHOWN)
 970                         continue;
 971
 972                 /* We want to show boundary commits only when their
 973                  * children are shown.  When path-limiter is in effect,
 974                  * rewrite_parents() drops some commits from getting shown,
 975                  * and there is no point showing boundary parents that
 976                  * are not shown.  After rewrite_parents() rewrites the
 977                  * parents of a commit that is shown, we mark the boundary
 978                  * parents with BOUNDARY_SHOW.
 979                  */
 980                 if (commit->object.flags & BOUNDARY_SHOW) {
 981                         commit->object.flags |= SHOWN;
 982                         return commit;
 983                 }
 984                 if (commit->object.flags & UNINTERESTING)
 985                         continue;
 986                 if (revs->min_age != -1 && (commit->date > revs->min_age))
 987                         continue;
 988                 if (revs->no_merges &&
 989                     commit->parents && commit->parents->next)
 990                         continue;
 991                 if (revs->prune_fn && revs->dense) {
 992                         if (!(commit->object.flags & TREECHANGE))
 993                                 continue;
 994                         if (revs->parents)
 995                                 rewrite_parents(revs, commit);
 996                 }
 997                 if (revs->boundary)
 998                         mark_boundary_to_show(commit);
 999                 commit->object.flags |= SHOWN;
1000                 return commit;
1001         } while (revs->commits);
1002         return NULL;
1003 }