revision.con commit Make index file locking code reusable to others. (021b6e4)
   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
  10static 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
  34struct 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
  47static void mark_blob_uninteresting(struct blob *blob)
  48{
  49        if (blob->object.flags & UNINTERESTING)
  50                return;
  51        blob->object.flags |= UNINTERESTING;
  52}
  53
  54void 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
  85void 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
 120static 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
 125static 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
 136static 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
 201static 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
 214static int tree_difference = REV_TREE_SAME;
 215
 216static 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
 239static 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
 248int 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
 261int 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
 285static 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 (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
 346static 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
 407static 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
 469static int all_flags;
 470static struct rev_info *all_revs;
 471
 472static 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
 479static 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
 486static 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
 516void 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->pruning.recursive = 1;
 523        revs->pruning.add_remove = file_add_remove;
 524        revs->pruning.change = file_change;
 525        revs->lifo = 1;
 526        revs->dense = 1;
 527        revs->prefix = setup_git_directory();
 528        revs->max_age = -1;
 529        revs->min_age = -1;
 530        revs->max_count = -1;
 531
 532        revs->prune_fn = NULL;
 533        revs->prune_data = NULL;
 534
 535        revs->topo_setter = topo_sort_default_setter;
 536        revs->topo_getter = topo_sort_default_getter;
 537
 538        revs->commit_format = CMIT_FMT_DEFAULT;
 539
 540        diff_setup(&revs->diffopt);
 541}
 542
 543/*
 544 * Parse revision information, filling in the "rev_info" structure,
 545 * and removing the used arguments from the argument list.
 546 *
 547 * Returns the number of arguments left that weren't recognized
 548 * (which are also moved to the head of the argument list)
 549 */
 550int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
 551{
 552        int i, flags, seen_dashdash;
 553        const char **unrecognized = argv + 1;
 554        int left = 1;
 555
 556        /* First, search for "--" */
 557        seen_dashdash = 0;
 558        for (i = 1; i < argc; i++) {
 559                const char *arg = argv[i];
 560                if (strcmp(arg, "--"))
 561                        continue;
 562                argv[i] = NULL;
 563                argc = i;
 564                revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
 565                seen_dashdash = 1;
 566                break;
 567        }
 568
 569        flags = 0;
 570        for (i = 1; i < argc; i++) {
 571                struct object *object;
 572                const char *arg = argv[i];
 573                unsigned char sha1[20];
 574                char *dotdot;
 575                int local_flags;
 576
 577                if (*arg == '-') {
 578                        int opts;
 579                        if (!strncmp(arg, "--max-count=", 12)) {
 580                                revs->max_count = atoi(arg + 12);
 581                                continue;
 582                        }
 583                        /* accept -<digit>, like traditional "head" */
 584                        if ((*arg == '-') && isdigit(arg[1])) {
 585                                revs->max_count = atoi(arg + 1);
 586                                continue;
 587                        }
 588                        if (!strcmp(arg, "-n")) {
 589                                if (argc <= i + 1)
 590                                        die("-n requires an argument");
 591                                revs->max_count = atoi(argv[++i]);
 592                                continue;
 593                        }
 594                        if (!strncmp(arg,"-n",2)) {
 595                                revs->max_count = atoi(arg + 2);
 596                                continue;
 597                        }
 598                        if (!strncmp(arg, "--max-age=", 10)) {
 599                                revs->max_age = atoi(arg + 10);
 600                                continue;
 601                        }
 602                        if (!strncmp(arg, "--since=", 8)) {
 603                                revs->max_age = approxidate(arg + 8);
 604                                continue;
 605                        }
 606                        if (!strncmp(arg, "--after=", 8)) {
 607                                revs->max_age = approxidate(arg + 8);
 608                                continue;
 609                        }
 610                        if (!strncmp(arg, "--min-age=", 10)) {
 611                                revs->min_age = atoi(arg + 10);
 612                                continue;
 613                        }
 614                        if (!strncmp(arg, "--before=", 9)) {
 615                                revs->min_age = approxidate(arg + 9);
 616                                continue;
 617                        }
 618                        if (!strncmp(arg, "--until=", 8)) {
 619                                revs->min_age = approxidate(arg + 8);
 620                                continue;
 621                        }
 622                        if (!strcmp(arg, "--all")) {
 623                                handle_all(revs, flags);
 624                                continue;
 625                        }
 626                        if (!strcmp(arg, "--not")) {
 627                                flags ^= UNINTERESTING;
 628                                continue;
 629                        }
 630                        if (!strcmp(arg, "--default")) {
 631                                if (++i >= argc)
 632                                        die("bad --default argument");
 633                                def = argv[i];
 634                                continue;
 635                        }
 636                        if (!strcmp(arg, "--topo-order")) {
 637                                revs->topo_order = 1;
 638                                continue;
 639                        }
 640                        if (!strcmp(arg, "--date-order")) {
 641                                revs->lifo = 0;
 642                                revs->topo_order = 1;
 643                                continue;
 644                        }
 645                        if (!strcmp(arg, "--parents")) {
 646                                revs->parents = 1;
 647                                continue;
 648                        }
 649                        if (!strcmp(arg, "--dense")) {
 650                                revs->dense = 1;
 651                                continue;
 652                        }
 653                        if (!strcmp(arg, "--sparse")) {
 654                                revs->dense = 0;
 655                                continue;
 656                        }
 657                        if (!strcmp(arg, "--remove-empty")) {
 658                                revs->remove_empty_trees = 1;
 659                                continue;
 660                        }
 661                        if (!strcmp(arg, "--no-merges")) {
 662                                revs->no_merges = 1;
 663                                continue;
 664                        }
 665                        if (!strcmp(arg, "--boundary")) {
 666                                revs->boundary = 1;
 667                                continue;
 668                        }
 669                        if (!strcmp(arg, "--objects")) {
 670                                revs->tag_objects = 1;
 671                                revs->tree_objects = 1;
 672                                revs->blob_objects = 1;
 673                                continue;
 674                        }
 675                        if (!strcmp(arg, "--objects-edge")) {
 676                                revs->tag_objects = 1;
 677                                revs->tree_objects = 1;
 678                                revs->blob_objects = 1;
 679                                revs->edge_hint = 1;
 680                                continue;
 681                        }
 682                        if (!strcmp(arg, "--unpacked")) {
 683                                revs->unpacked = 1;
 684                                continue;
 685                        }
 686                        if (!strcmp(arg, "-r")) {
 687                                revs->diff = 1;
 688                                revs->diffopt.recursive = 1;
 689                                continue;
 690                        }
 691                        if (!strcmp(arg, "-t")) {
 692                                revs->diff = 1;
 693                                revs->diffopt.recursive = 1;
 694                                revs->diffopt.tree_in_recursive = 1;
 695                                continue;
 696                        }
 697                        if (!strcmp(arg, "-m")) {
 698                                revs->ignore_merges = 0;
 699                                continue;
 700                        }
 701                        if (!strcmp(arg, "-c")) {
 702                                revs->diff = 1;
 703                                revs->dense_combined_merges = 0;
 704                                revs->combine_merges = 1;
 705                                continue;
 706                        }
 707                        if (!strcmp(arg, "--cc")) {
 708                                revs->diff = 1;
 709                                revs->dense_combined_merges = 1;
 710                                revs->combine_merges = 1;
 711                                continue;
 712                        }
 713                        if (!strcmp(arg, "-v")) {
 714                                revs->verbose_header = 1;
 715                                continue;
 716                        }
 717                        if (!strncmp(arg, "--pretty", 8)) {
 718                                revs->verbose_header = 1;
 719                                revs->commit_format = get_commit_format(arg+8);
 720                                continue;
 721                        }
 722                        if (!strcmp(arg, "--root")) {
 723                                revs->show_root_diff = 1;
 724                                continue;
 725                        }
 726                        if (!strcmp(arg, "--no-commit-id")) {
 727                                revs->no_commit_id = 1;
 728                                continue;
 729                        }
 730                        if (!strcmp(arg, "--always")) {
 731                                revs->always_show_header = 1;
 732                                continue;
 733                        }
 734                        if (!strcmp(arg, "--no-abbrev")) {
 735                                revs->abbrev = 0;
 736                                continue;
 737                        }
 738                        if (!strcmp(arg, "--abbrev")) {
 739                                revs->abbrev = DEFAULT_ABBREV;
 740                                continue;
 741                        }
 742                        if (!strncmp(arg, "--abbrev=", 9)) {
 743                                revs->abbrev = strtoul(arg + 9, NULL, 10);
 744                                if (revs->abbrev < MINIMUM_ABBREV)
 745                                        revs->abbrev = MINIMUM_ABBREV;
 746                                else if (revs->abbrev > 40)
 747                                        revs->abbrev = 40;
 748                                continue;
 749                        }
 750                        if (!strcmp(arg, "--abbrev-commit")) {
 751                                revs->abbrev_commit = 1;
 752                                continue;
 753                        }
 754                        if (!strcmp(arg, "--full-diff")) {
 755                                revs->diff = 1;
 756                                revs->full_diff = 1;
 757                                continue;
 758                        }
 759                        opts = diff_opt_parse(&revs->diffopt, argv+i, argc-i);
 760                        if (opts > 0) {
 761                                revs->diff = 1;
 762                                i += opts - 1;
 763                                continue;
 764                        }
 765                        *unrecognized++ = arg;
 766                        left++;
 767                        continue;
 768                }
 769                dotdot = strstr(arg, "..");
 770                if (dotdot) {
 771                        unsigned char from_sha1[20];
 772                        const char *next = dotdot + 2;
 773                        const char *this = arg;
 774                        *dotdot = 0;
 775                        if (!*next)
 776                                next = "HEAD";
 777                        if (dotdot == arg)
 778                                this = "HEAD";
 779                        if (!get_sha1(this, from_sha1) &&
 780                            !get_sha1(next, sha1)) {
 781                                struct object *exclude;
 782                                struct object *include;
 783
 784                                exclude = get_reference(revs, this, from_sha1, flags ^ UNINTERESTING);
 785                                include = get_reference(revs, next, sha1, flags);
 786                                if (!exclude || !include)
 787                                        die("Invalid revision range %s..%s", arg, next);
 788
 789                                if (!seen_dashdash) {
 790                                        *dotdot = '.';
 791                                        verify_non_filename(revs->prefix, arg);
 792                                }
 793                                add_pending_object(revs, exclude, this);
 794                                add_pending_object(revs, include, next);
 795                                continue;
 796                        }
 797                        *dotdot = '.';
 798                }
 799                dotdot = strstr(arg, "^@");
 800                if (dotdot && !dotdot[2]) {
 801                        *dotdot = 0;
 802                        if (add_parents_only(revs, arg, flags))
 803                                continue;
 804                        *dotdot = '^';
 805                }
 806                local_flags = 0;
 807                if (*arg == '^') {
 808                        local_flags = UNINTERESTING;
 809                        arg++;
 810                }
 811                if (get_sha1(arg, sha1)) {
 812                        int j;
 813
 814                        if (seen_dashdash || local_flags)
 815                                die("bad revision '%s'", arg);
 816
 817                        /* If we didn't have a "--":
 818                         * (1) all filenames must exist;
 819                         * (2) all rev-args must not be interpretable
 820                         *     as a valid filename.
 821                         * but the latter we have checked in the main loop.
 822                         */
 823                        for (j = i; j < argc; j++)
 824                                verify_filename(revs->prefix, argv[j]);
 825
 826                        revs->prune_data = get_pathspec(revs->prefix, argv + i);
 827                        break;
 828                }
 829                if (!seen_dashdash)
 830                        verify_non_filename(revs->prefix, arg);
 831                object = get_reference(revs, arg, sha1, flags ^ local_flags);
 832                add_pending_object(revs, object, arg);
 833        }
 834        if (def && !revs->pending_objects) {
 835                unsigned char sha1[20];
 836                struct object *object;
 837                if (get_sha1(def, sha1))
 838                        die("bad default revision '%s'", def);
 839                object = get_reference(revs, def, sha1, 0);
 840                add_pending_object(revs, object, def);
 841        }
 842
 843        if (revs->topo_order || revs->unpacked)
 844                revs->limited = 1;
 845
 846        if (revs->prune_data) {
 847                diff_tree_setup_paths(revs->prune_data, &revs->pruning);
 848                revs->prune_fn = try_to_simplify_commit;
 849                if (!revs->full_diff)
 850                        diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
 851        }
 852        if (revs->combine_merges) {
 853                revs->ignore_merges = 0;
 854                if (revs->dense_combined_merges &&
 855                    (revs->diffopt.output_format != DIFF_FORMAT_DIFFSTAT))
 856                        revs->diffopt.output_format = DIFF_FORMAT_PATCH;
 857        }
 858        revs->diffopt.abbrev = revs->abbrev;
 859        diff_setup_done(&revs->diffopt);
 860
 861        return left;
 862}
 863
 864void prepare_revision_walk(struct rev_info *revs)
 865{
 866        struct object_list *list;
 867
 868        list = revs->pending_objects;
 869        revs->pending_objects = NULL;
 870        while (list) {
 871                struct commit *commit = handle_commit(revs, list->item, list->name);
 872                if (commit) {
 873                        if (!(commit->object.flags & SEEN)) {
 874                                commit->object.flags |= SEEN;
 875                                insert_by_date(commit, &revs->commits);
 876                        }
 877                }
 878                list = list->next;
 879        }
 880
 881        if (revs->no_walk)
 882                return;
 883        if (revs->limited)
 884                limit_list(revs);
 885        if (revs->topo_order)
 886                sort_in_topological_order_fn(&revs->commits, revs->lifo,
 887                                             revs->topo_setter,
 888                                             revs->topo_getter);
 889}
 890
 891static int rewrite_one(struct rev_info *revs, struct commit **pp)
 892{
 893        for (;;) {
 894                struct commit *p = *pp;
 895                if (!revs->limited)
 896                        add_parents_to_list(revs, p, &revs->commits);
 897                if (p->object.flags & (TREECHANGE | UNINTERESTING))
 898                        return 0;
 899                if (!p->parents)
 900                        return -1;
 901                *pp = p->parents->item;
 902        }
 903}
 904
 905static void rewrite_parents(struct rev_info *revs, struct commit *commit)
 906{
 907        struct commit_list **pp = &commit->parents;
 908        while (*pp) {
 909                struct commit_list *parent = *pp;
 910                if (rewrite_one(revs, &parent->item) < 0) {
 911                        *pp = parent->next;
 912                        continue;
 913                }
 914                pp = &parent->next;
 915        }
 916}
 917
 918static void mark_boundary_to_show(struct commit *commit)
 919{
 920        struct commit_list *p = commit->parents;
 921        while (p) {
 922                commit = p->item;
 923                p = p->next;
 924                if (commit->object.flags & BOUNDARY)
 925                        commit->object.flags |= BOUNDARY_SHOW;
 926        }
 927}
 928
 929struct commit *get_revision(struct rev_info *revs)
 930{
 931        struct commit_list *list = revs->commits;
 932
 933        if (!list)
 934                return NULL;
 935
 936        /* Check the max_count ... */
 937        switch (revs->max_count) {
 938        case -1:
 939                break;
 940        case 0:
 941                return NULL;
 942        default:
 943                revs->max_count--;
 944        }
 945
 946        do {
 947                struct commit *commit = revs->commits->item;
 948
 949                revs->commits = revs->commits->next;
 950
 951                /*
 952                 * If we haven't done the list limiting, we need to look at
 953                 * the parents here. We also need to do the date-based limiting
 954                 * that we'd otherwise have done in limit_list().
 955                 */
 956                if (!revs->limited) {
 957                        if ((revs->unpacked &&
 958                             has_sha1_pack(commit->object.sha1)) ||
 959                            (revs->max_age != -1 &&
 960                             (commit->date < revs->max_age)))
 961                                continue;
 962                        add_parents_to_list(revs, commit, &revs->commits);
 963                }
 964                if (commit->object.flags & SHOWN)
 965                        continue;
 966
 967                /* We want to show boundary commits only when their
 968                 * children are shown.  When path-limiter is in effect,
 969                 * rewrite_parents() drops some commits from getting shown,
 970                 * and there is no point showing boundary parents that
 971                 * are not shown.  After rewrite_parents() rewrites the
 972                 * parents of a commit that is shown, we mark the boundary
 973                 * parents with BOUNDARY_SHOW.
 974                 */
 975                if (commit->object.flags & BOUNDARY_SHOW) {
 976                        commit->object.flags |= SHOWN;
 977                        return commit;
 978                }
 979                if (commit->object.flags & UNINTERESTING)
 980                        continue;
 981                if (revs->min_age != -1 && (commit->date > revs->min_age))
 982                        continue;
 983                if (revs->no_merges &&
 984                    commit->parents && commit->parents->next)
 985                        continue;
 986                if (revs->prune_fn && revs->dense) {
 987                        if (!(commit->object.flags & TREECHANGE))
 988                                continue;
 989                        if (revs->parents)
 990                                rewrite_parents(revs, commit);
 991                }
 992                if (revs->boundary)
 993                        mark_boundary_to_show(commit);
 994                commit->object.flags |= SHOWN;
 995                return commit;
 996        } while (revs->commits);
 997        return NULL;
 998}