revision.con commit Make clear_commit_marks() clean harder (31aea7e)
   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
  34void add_object(struct object *obj,
  35                struct object_array *p,
  36                struct name_path *path,
  37                const char *name)
  38{
  39        add_object_array(obj, path_name(path, name), p);
  40}
  41
  42static void mark_blob_uninteresting(struct blob *blob)
  43{
  44        if (blob->object.flags & UNINTERESTING)
  45                return;
  46        blob->object.flags |= UNINTERESTING;
  47}
  48
  49void mark_tree_uninteresting(struct tree *tree)
  50{
  51        struct tree_desc desc;
  52        struct name_entry entry;
  53        struct object *obj = &tree->object;
  54
  55        if (obj->flags & UNINTERESTING)
  56                return;
  57        obj->flags |= UNINTERESTING;
  58        if (!has_sha1_file(obj->sha1))
  59                return;
  60        if (parse_tree(tree) < 0)
  61                die("bad tree %s", sha1_to_hex(obj->sha1));
  62
  63        desc.buf = tree->buffer;
  64        desc.size = tree->size;
  65        while (tree_entry(&desc, &entry)) {
  66                if (S_ISDIR(entry.mode))
  67                        mark_tree_uninteresting(lookup_tree(entry.sha1));
  68                else
  69                        mark_blob_uninteresting(lookup_blob(entry.sha1));
  70        }
  71
  72        /*
  73         * We don't care about the tree any more
  74         * after it has been marked uninteresting.
  75         */
  76        free(tree->buffer);
  77        tree->buffer = NULL;
  78}
  79
  80void mark_parents_uninteresting(struct commit *commit)
  81{
  82        struct commit_list *parents = commit->parents;
  83
  84        while (parents) {
  85                struct commit *commit = parents->item;
  86                if (!(commit->object.flags & UNINTERESTING)) {
  87                        commit->object.flags |= UNINTERESTING;
  88
  89                        /*
  90                         * Normally we haven't parsed the parent
  91                         * yet, so we won't have a parent of a parent
  92                         * here. However, it may turn out that we've
  93                         * reached this commit some other way (where it
  94                         * wasn't uninteresting), in which case we need
  95                         * to mark its parents recursively too..
  96                         */
  97                        if (commit->parents)
  98                                mark_parents_uninteresting(commit);
  99                }
 100
 101                /*
 102                 * A missing commit is ok iff its parent is marked
 103                 * uninteresting.
 104                 *
 105                 * We just mark such a thing parsed, so that when
 106                 * it is popped next time around, we won't be trying
 107                 * to parse it and get an error.
 108                 */
 109                if (!has_sha1_file(commit->object.sha1))
 110                        commit->object.parsed = 1;
 111                parents = parents->next;
 112        }
 113}
 114
 115void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
 116{
 117        add_object_array(obj, name, &revs->pending);
 118}
 119
 120static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
 121{
 122        struct object *object;
 123
 124        object = parse_object(sha1);
 125        if (!object)
 126                die("bad object %s", name);
 127        object->flags |= flags;
 128        return object;
 129}
 130
 131static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
 132{
 133        unsigned long flags = object->flags;
 134
 135        /*
 136         * Tag object? Look what it points to..
 137         */
 138        while (object->type == TYPE_TAG) {
 139                struct tag *tag = (struct tag *) object;
 140                if (revs->tag_objects && !(flags & UNINTERESTING))
 141                        add_pending_object(revs, object, tag->tag);
 142                object = parse_object(tag->tagged->sha1);
 143                if (!object)
 144                        die("bad object %s", sha1_to_hex(tag->tagged->sha1));
 145        }
 146
 147        /*
 148         * Commit object? Just return it, we'll do all the complex
 149         * reachability crud.
 150         */
 151        if (object->type == TYPE_COMMIT) {
 152                struct commit *commit = (struct commit *)object;
 153                if (parse_commit(commit) < 0)
 154                        die("unable to parse commit %s", name);
 155                if (flags & UNINTERESTING) {
 156                        commit->object.flags |= UNINTERESTING;
 157                        mark_parents_uninteresting(commit);
 158                        revs->limited = 1;
 159                }
 160                return commit;
 161        }
 162
 163        /*
 164         * Tree object? Either mark it uniniteresting, or add it
 165         * to the list of objects to look at later..
 166         */
 167        if (object->type == TYPE_TREE) {
 168                struct tree *tree = (struct tree *)object;
 169                if (!revs->tree_objects)
 170                        return NULL;
 171                if (flags & UNINTERESTING) {
 172                        mark_tree_uninteresting(tree);
 173                        return NULL;
 174                }
 175                add_pending_object(revs, object, "");
 176                return NULL;
 177        }
 178
 179        /*
 180         * Blob object? You know the drill by now..
 181         */
 182        if (object->type == TYPE_BLOB) {
 183                struct blob *blob = (struct blob *)object;
 184                if (!revs->blob_objects)
 185                        return NULL;
 186                if (flags & UNINTERESTING) {
 187                        mark_blob_uninteresting(blob);
 188                        return NULL;
 189                }
 190                add_pending_object(revs, object, "");
 191                return NULL;
 192        }
 193        die("%s is unknown object", name);
 194}
 195
 196static int everybody_uninteresting(struct commit_list *orig)
 197{
 198        struct commit_list *list = orig;
 199        while (list) {
 200                struct commit *commit = list->item;
 201                list = list->next;
 202                if (commit->object.flags & UNINTERESTING)
 203                        continue;
 204                return 0;
 205        }
 206        return 1;
 207}
 208
 209static int tree_difference = REV_TREE_SAME;
 210
 211static void file_add_remove(struct diff_options *options,
 212                    int addremove, unsigned mode,
 213                    const unsigned char *sha1,
 214                    const char *base, const char *path)
 215{
 216        int diff = REV_TREE_DIFFERENT;
 217
 218        /*
 219         * Is it an add of a new file? It means that the old tree
 220         * didn't have it at all, so we will turn "REV_TREE_SAME" ->
 221         * "REV_TREE_NEW", but leave any "REV_TREE_DIFFERENT" alone
 222         * (and if it already was "REV_TREE_NEW", we'll keep it
 223         * "REV_TREE_NEW" of course).
 224         */
 225        if (addremove == '+') {
 226                diff = tree_difference;
 227                if (diff != REV_TREE_SAME)
 228                        return;
 229                diff = REV_TREE_NEW;
 230        }
 231        tree_difference = diff;
 232}
 233
 234static void file_change(struct diff_options *options,
 235                 unsigned old_mode, unsigned new_mode,
 236                 const unsigned char *old_sha1,
 237                 const unsigned char *new_sha1,
 238                 const char *base, const char *path)
 239{
 240        tree_difference = REV_TREE_DIFFERENT;
 241}
 242
 243int rev_compare_tree(struct rev_info *revs, struct tree *t1, struct tree *t2)
 244{
 245        if (!t1)
 246                return REV_TREE_NEW;
 247        if (!t2)
 248                return REV_TREE_DIFFERENT;
 249        tree_difference = REV_TREE_SAME;
 250        if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
 251                           &revs->pruning) < 0)
 252                return REV_TREE_DIFFERENT;
 253        return tree_difference;
 254}
 255
 256int rev_same_tree_as_empty(struct rev_info *revs, struct tree *t1)
 257{
 258        int retval;
 259        void *tree;
 260        struct tree_desc empty, real;
 261
 262        if (!t1)
 263                return 0;
 264
 265        tree = read_object_with_reference(t1->object.sha1, tree_type, &real.size, NULL);
 266        if (!tree)
 267                return 0;
 268        real.buf = tree;
 269
 270        empty.buf = "";
 271        empty.size = 0;
 272
 273        tree_difference = 0;
 274        retval = diff_tree(&empty, &real, "", &revs->pruning);
 275        free(tree);
 276
 277        return retval >= 0 && !tree_difference;
 278}
 279
 280static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 281{
 282        struct commit_list **pp, *parent;
 283        int tree_changed = 0;
 284
 285        if (!commit->tree)
 286                return;
 287
 288        if (!commit->parents) {
 289                if (!rev_same_tree_as_empty(revs, commit->tree))
 290                        commit->object.flags |= TREECHANGE;
 291                return;
 292        }
 293
 294        pp = &commit->parents;
 295        while ((parent = *pp) != NULL) {
 296                struct commit *p = parent->item;
 297
 298                parse_commit(p);
 299                switch (rev_compare_tree(revs, p->tree, commit->tree)) {
 300                case REV_TREE_SAME:
 301                        if (!revs->simplify_history || (p->object.flags & UNINTERESTING)) {
 302                                /* Even if a merge with an uninteresting
 303                                 * side branch brought the entire change
 304                                 * we are interested in, we do not want
 305                                 * to lose the other branches of this
 306                                 * merge, so we just keep going.
 307                                 */
 308                                pp = &parent->next;
 309                                continue;
 310                        }
 311                        parent->next = NULL;
 312                        commit->parents = parent;
 313                        return;
 314
 315                case REV_TREE_NEW:
 316                        if (revs->remove_empty_trees &&
 317                            rev_same_tree_as_empty(revs, p->tree)) {
 318                                /* We are adding all the specified
 319                                 * paths from this parent, so the
 320                                 * history beyond this parent is not
 321                                 * interesting.  Remove its parents
 322                                 * (they are grandparents for us).
 323                                 * IOW, we pretend this parent is a
 324                                 * "root" commit.
 325                                 */
 326                                parse_commit(p);
 327                                p->parents = NULL;
 328                        }
 329                /* fallthrough */
 330                case REV_TREE_DIFFERENT:
 331                        tree_changed = 1;
 332                        pp = &parent->next;
 333                        continue;
 334                }
 335                die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
 336        }
 337        if (tree_changed)
 338                commit->object.flags |= TREECHANGE;
 339}
 340
 341static void add_parents_to_list(struct rev_info *revs, struct commit *commit, struct commit_list **list)
 342{
 343        struct commit_list *parent = commit->parents;
 344
 345        if (commit->object.flags & ADDED)
 346                return;
 347        commit->object.flags |= ADDED;
 348
 349        /*
 350         * If the commit is uninteresting, don't try to
 351         * prune parents - we want the maximal uninteresting
 352         * set.
 353         *
 354         * Normally we haven't parsed the parent
 355         * yet, so we won't have a parent of a parent
 356         * here. However, it may turn out that we've
 357         * reached this commit some other way (where it
 358         * wasn't uninteresting), in which case we need
 359         * to mark its parents recursively too..
 360         */
 361        if (commit->object.flags & UNINTERESTING) {
 362                while (parent) {
 363                        struct commit *p = parent->item;
 364                        parent = parent->next;
 365                        parse_commit(p);
 366                        p->object.flags |= UNINTERESTING;
 367                        if (p->parents)
 368                                mark_parents_uninteresting(p);
 369                        if (p->object.flags & SEEN)
 370                                continue;
 371                        p->object.flags |= SEEN;
 372                        insert_by_date(p, list);
 373                }
 374                return;
 375        }
 376
 377        /*
 378         * Ok, the commit wasn't uninteresting. Try to
 379         * simplify the commit history and find the parent
 380         * that has no differences in the path set if one exists.
 381         */
 382        if (revs->prune_fn)
 383                revs->prune_fn(revs, commit);
 384
 385        if (revs->no_walk)
 386                return;
 387
 388        parent = commit->parents;
 389        while (parent) {
 390                struct commit *p = parent->item;
 391
 392                parent = parent->next;
 393
 394                parse_commit(p);
 395                if (p->object.flags & SEEN)
 396                        continue;
 397                p->object.flags |= SEEN;
 398                insert_by_date(p, list);
 399        }
 400}
 401
 402static void limit_list(struct rev_info *revs)
 403{
 404        struct commit_list *list = revs->commits;
 405        struct commit_list *newlist = NULL;
 406        struct commit_list **p = &newlist;
 407
 408        while (list) {
 409                struct commit_list *entry = list;
 410                struct commit *commit = list->item;
 411                struct object *obj = &commit->object;
 412
 413                list = list->next;
 414                free(entry);
 415
 416                if (revs->max_age != -1 && (commit->date < revs->max_age))
 417                        obj->flags |= UNINTERESTING;
 418                if (revs->unpacked && has_sha1_pack(obj->sha1))
 419                        obj->flags |= UNINTERESTING;
 420                add_parents_to_list(revs, commit, &list);
 421                if (obj->flags & UNINTERESTING) {
 422                        mark_parents_uninteresting(commit);
 423                        if (everybody_uninteresting(list))
 424                                break;
 425                        continue;
 426                }
 427                if (revs->min_age != -1 && (commit->date > revs->min_age))
 428                        continue;
 429                p = &commit_list_insert(commit, p)->next;
 430        }
 431        if (revs->boundary) {
 432                /* mark the ones that are on the result list first */
 433                for (list = newlist; list; list = list->next) {
 434                        struct commit *commit = list->item;
 435                        commit->object.flags |= TMP_MARK;
 436                }
 437                for (list = newlist; list; list = list->next) {
 438                        struct commit *commit = list->item;
 439                        struct object *obj = &commit->object;
 440                        struct commit_list *parent;
 441                        if (obj->flags & UNINTERESTING)
 442                                continue;
 443                        for (parent = commit->parents;
 444                             parent;
 445                             parent = parent->next) {
 446                                struct commit *pcommit = parent->item;
 447                                if (!(pcommit->object.flags & UNINTERESTING))
 448                                        continue;
 449                                pcommit->object.flags |= BOUNDARY;
 450                                if (pcommit->object.flags & TMP_MARK)
 451                                        continue;
 452                                pcommit->object.flags |= TMP_MARK;
 453                                p = &commit_list_insert(pcommit, p)->next;
 454                        }
 455                }
 456                for (list = newlist; list; list = list->next) {
 457                        struct commit *commit = list->item;
 458                        commit->object.flags &= ~TMP_MARK;
 459                }
 460        }
 461        revs->commits = newlist;
 462}
 463
 464static int all_flags;
 465static struct rev_info *all_revs;
 466
 467static int handle_one_ref(const char *path, const unsigned char *sha1)
 468{
 469        struct object *object = get_reference(all_revs, path, sha1, all_flags);
 470        add_pending_object(all_revs, object, "");
 471        return 0;
 472}
 473
 474static void handle_all(struct rev_info *revs, unsigned flags)
 475{
 476        all_revs = revs;
 477        all_flags = flags;
 478        for_each_ref(handle_one_ref);
 479}
 480
 481static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
 482{
 483        unsigned char sha1[20];
 484        struct object *it;
 485        struct commit *commit;
 486        struct commit_list *parents;
 487
 488        if (*arg == '^') {
 489                flags ^= UNINTERESTING;
 490                arg++;
 491        }
 492        if (get_sha1(arg, sha1))
 493                return 0;
 494        while (1) {
 495                it = get_reference(revs, arg, sha1, 0);
 496                if (it->type != TYPE_TAG)
 497                        break;
 498                memcpy(sha1, ((struct tag*)it)->tagged->sha1, 20);
 499        }
 500        if (it->type != TYPE_COMMIT)
 501                return 0;
 502        commit = (struct commit *)it;
 503        for (parents = commit->parents; parents; parents = parents->next) {
 504                it = &parents->item->object;
 505                it->flags |= flags;
 506                add_pending_object(revs, it, arg);
 507        }
 508        return 1;
 509}
 510
 511void init_revisions(struct rev_info *revs)
 512{
 513        memset(revs, 0, sizeof(*revs));
 514
 515        revs->abbrev = DEFAULT_ABBREV;
 516        revs->ignore_merges = 1;
 517        revs->simplify_history = 1;
 518        revs->pruning.recursive = 1;
 519        revs->pruning.add_remove = file_add_remove;
 520        revs->pruning.change = file_change;
 521        revs->lifo = 1;
 522        revs->dense = 1;
 523        revs->prefix = setup_git_directory();
 524        revs->max_age = -1;
 525        revs->min_age = -1;
 526        revs->max_count = -1;
 527
 528        revs->prune_fn = NULL;
 529        revs->prune_data = NULL;
 530
 531        revs->topo_setter = topo_sort_default_setter;
 532        revs->topo_getter = topo_sort_default_getter;
 533
 534        revs->commit_format = CMIT_FMT_DEFAULT;
 535
 536        diff_setup(&revs->diffopt);
 537}
 538
 539static void add_pending_commit_list(struct rev_info *revs,
 540                                    struct commit_list *commit_list,
 541                                    unsigned int flags)
 542{
 543        while (commit_list) {
 544                struct object *object = &commit_list->item->object;
 545                object->flags |= flags;
 546                add_pending_object(revs, object, sha1_to_hex(object->sha1));
 547                commit_list = commit_list->next;
 548        }
 549}
 550
 551/*
 552 * Parse revision information, filling in the "rev_info" structure,
 553 * and removing the used arguments from the argument list.
 554 *
 555 * Returns the number of arguments left that weren't recognized
 556 * (which are also moved to the head of the argument list)
 557 */
 558int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
 559{
 560        int i, flags, seen_dashdash;
 561        const char **unrecognized = argv + 1;
 562        int left = 1;
 563
 564        /* First, search for "--" */
 565        seen_dashdash = 0;
 566        for (i = 1; i < argc; i++) {
 567                const char *arg = argv[i];
 568                if (strcmp(arg, "--"))
 569                        continue;
 570                argv[i] = NULL;
 571                argc = i;
 572                revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
 573                seen_dashdash = 1;
 574                break;
 575        }
 576
 577        flags = 0;
 578        for (i = 1; i < argc; i++) {
 579                struct object *object;
 580                const char *arg = argv[i];
 581                unsigned char sha1[20];
 582                char *dotdot;
 583                int local_flags;
 584
 585                if (*arg == '-') {
 586                        int opts;
 587                        if (!strncmp(arg, "--max-count=", 12)) {
 588                                revs->max_count = atoi(arg + 12);
 589                                continue;
 590                        }
 591                        /* accept -<digit>, like traditional "head" */
 592                        if ((*arg == '-') && isdigit(arg[1])) {
 593                                revs->max_count = atoi(arg + 1);
 594                                continue;
 595                        }
 596                        if (!strcmp(arg, "-n")) {
 597                                if (argc <= i + 1)
 598                                        die("-n requires an argument");
 599                                revs->max_count = atoi(argv[++i]);
 600                                continue;
 601                        }
 602                        if (!strncmp(arg,"-n",2)) {
 603                                revs->max_count = atoi(arg + 2);
 604                                continue;
 605                        }
 606                        if (!strncmp(arg, "--max-age=", 10)) {
 607                                revs->max_age = atoi(arg + 10);
 608                                continue;
 609                        }
 610                        if (!strncmp(arg, "--since=", 8)) {
 611                                revs->max_age = approxidate(arg + 8);
 612                                continue;
 613                        }
 614                        if (!strncmp(arg, "--after=", 8)) {
 615                                revs->max_age = approxidate(arg + 8);
 616                                continue;
 617                        }
 618                        if (!strncmp(arg, "--min-age=", 10)) {
 619                                revs->min_age = atoi(arg + 10);
 620                                continue;
 621                        }
 622                        if (!strncmp(arg, "--before=", 9)) {
 623                                revs->min_age = approxidate(arg + 9);
 624                                continue;
 625                        }
 626                        if (!strncmp(arg, "--until=", 8)) {
 627                                revs->min_age = approxidate(arg + 8);
 628                                continue;
 629                        }
 630                        if (!strcmp(arg, "--all")) {
 631                                handle_all(revs, flags);
 632                                continue;
 633                        }
 634                        if (!strcmp(arg, "--not")) {
 635                                flags ^= UNINTERESTING;
 636                                continue;
 637                        }
 638                        if (!strcmp(arg, "--default")) {
 639                                if (++i >= argc)
 640                                        die("bad --default argument");
 641                                def = argv[i];
 642                                continue;
 643                        }
 644                        if (!strcmp(arg, "--topo-order")) {
 645                                revs->topo_order = 1;
 646                                continue;
 647                        }
 648                        if (!strcmp(arg, "--date-order")) {
 649                                revs->lifo = 0;
 650                                revs->topo_order = 1;
 651                                continue;
 652                        }
 653                        if (!strcmp(arg, "--parents")) {
 654                                revs->parents = 1;
 655                                continue;
 656                        }
 657                        if (!strcmp(arg, "--dense")) {
 658                                revs->dense = 1;
 659                                continue;
 660                        }
 661                        if (!strcmp(arg, "--sparse")) {
 662                                revs->dense = 0;
 663                                continue;
 664                        }
 665                        if (!strcmp(arg, "--remove-empty")) {
 666                                revs->remove_empty_trees = 1;
 667                                continue;
 668                        }
 669                        if (!strcmp(arg, "--no-merges")) {
 670                                revs->no_merges = 1;
 671                                continue;
 672                        }
 673                        if (!strcmp(arg, "--boundary")) {
 674                                revs->boundary = 1;
 675                                continue;
 676                        }
 677                        if (!strcmp(arg, "--objects")) {
 678                                revs->tag_objects = 1;
 679                                revs->tree_objects = 1;
 680                                revs->blob_objects = 1;
 681                                continue;
 682                        }
 683                        if (!strcmp(arg, "--objects-edge")) {
 684                                revs->tag_objects = 1;
 685                                revs->tree_objects = 1;
 686                                revs->blob_objects = 1;
 687                                revs->edge_hint = 1;
 688                                continue;
 689                        }
 690                        if (!strcmp(arg, "--unpacked")) {
 691                                revs->unpacked = 1;
 692                                continue;
 693                        }
 694                        if (!strcmp(arg, "-r")) {
 695                                revs->diff = 1;
 696                                revs->diffopt.recursive = 1;
 697                                continue;
 698                        }
 699                        if (!strcmp(arg, "-t")) {
 700                                revs->diff = 1;
 701                                revs->diffopt.recursive = 1;
 702                                revs->diffopt.tree_in_recursive = 1;
 703                                continue;
 704                        }
 705                        if (!strcmp(arg, "-m")) {
 706                                revs->ignore_merges = 0;
 707                                continue;
 708                        }
 709                        if (!strcmp(arg, "-c")) {
 710                                revs->diff = 1;
 711                                revs->dense_combined_merges = 0;
 712                                revs->combine_merges = 1;
 713                                continue;
 714                        }
 715                        if (!strcmp(arg, "--cc")) {
 716                                revs->diff = 1;
 717                                revs->dense_combined_merges = 1;
 718                                revs->combine_merges = 1;
 719                                continue;
 720                        }
 721                        if (!strcmp(arg, "-v")) {
 722                                revs->verbose_header = 1;
 723                                continue;
 724                        }
 725                        if (!strncmp(arg, "--pretty", 8)) {
 726                                revs->verbose_header = 1;
 727                                revs->commit_format = get_commit_format(arg+8);
 728                                continue;
 729                        }
 730                        if (!strcmp(arg, "--root")) {
 731                                revs->show_root_diff = 1;
 732                                continue;
 733                        }
 734                        if (!strcmp(arg, "--no-commit-id")) {
 735                                revs->no_commit_id = 1;
 736                                continue;
 737                        }
 738                        if (!strcmp(arg, "--always")) {
 739                                revs->always_show_header = 1;
 740                                continue;
 741                        }
 742                        if (!strcmp(arg, "--no-abbrev")) {
 743                                revs->abbrev = 0;
 744                                continue;
 745                        }
 746                        if (!strcmp(arg, "--abbrev")) {
 747                                revs->abbrev = DEFAULT_ABBREV;
 748                                continue;
 749                        }
 750                        if (!strncmp(arg, "--abbrev=", 9)) {
 751                                revs->abbrev = strtoul(arg + 9, NULL, 10);
 752                                if (revs->abbrev < MINIMUM_ABBREV)
 753                                        revs->abbrev = MINIMUM_ABBREV;
 754                                else if (revs->abbrev > 40)
 755                                        revs->abbrev = 40;
 756                                continue;
 757                        }
 758                        if (!strcmp(arg, "--abbrev-commit")) {
 759                                revs->abbrev_commit = 1;
 760                                continue;
 761                        }
 762                        if (!strcmp(arg, "--full-diff")) {
 763                                revs->diff = 1;
 764                                revs->full_diff = 1;
 765                                continue;
 766                        }
 767                        if (!strcmp(arg, "--full-history")) {
 768                                revs->simplify_history = 0;
 769                                continue;
 770                        }
 771                        opts = diff_opt_parse(&revs->diffopt, argv+i, argc-i);
 772                        if (opts > 0) {
 773                                revs->diff = 1;
 774                                i += opts - 1;
 775                                continue;
 776                        }
 777                        *unrecognized++ = arg;
 778                        left++;
 779                        continue;
 780                }
 781                dotdot = strstr(arg, "..");
 782                if (dotdot) {
 783                        unsigned char from_sha1[20];
 784                        const char *next = dotdot + 2;
 785                        const char *this = arg;
 786                        int symmetric = *next == '.';
 787                        unsigned int flags_exclude = flags ^ UNINTERESTING;
 788
 789                        *dotdot = 0;
 790                        next += symmetric;
 791
 792                        if (!*next)
 793                                next = "HEAD";
 794                        if (dotdot == arg)
 795                                this = "HEAD";
 796                        if (!get_sha1(this, from_sha1) &&
 797                            !get_sha1(next, sha1)) {
 798                                struct commit *a, *b;
 799                                struct commit_list *exclude;
 800
 801                                a = lookup_commit_reference(from_sha1);
 802                                b = lookup_commit_reference(sha1);
 803                                if (!a || !b) {
 804                                        die(symmetric ?
 805                                            "Invalid symmetric difference expression %s...%s" :
 806                                            "Invalid revision range %s..%s",
 807                                            arg, next);
 808                                }
 809
 810                                if (!seen_dashdash) {
 811                                        *dotdot = '.';
 812                                        verify_non_filename(revs->prefix, arg);
 813                                }
 814
 815                                if (symmetric) {
 816                                        exclude = get_merge_bases_clean(a, b);
 817                                        add_pending_commit_list(revs, exclude,
 818                                                                flags_exclude);
 819                                        a->object.flags |= flags;
 820                                } else
 821                                        a->object.flags |= flags_exclude;
 822                                b->object.flags |= flags;
 823                                add_pending_object(revs, &a->object, this);
 824                                add_pending_object(revs, &b->object, next);
 825                                continue;
 826                        }
 827                        *dotdot = '.';
 828                }
 829                dotdot = strstr(arg, "^@");
 830                if (dotdot && !dotdot[2]) {
 831                        *dotdot = 0;
 832                        if (add_parents_only(revs, arg, flags))
 833                                continue;
 834                        *dotdot = '^';
 835                }
 836                local_flags = 0;
 837                if (*arg == '^') {
 838                        local_flags = UNINTERESTING;
 839                        arg++;
 840                }
 841                if (get_sha1(arg, sha1)) {
 842                        int j;
 843
 844                        if (seen_dashdash || local_flags)
 845                                die("bad revision '%s'", arg);
 846
 847                        /* If we didn't have a "--":
 848                         * (1) all filenames must exist;
 849                         * (2) all rev-args must not be interpretable
 850                         *     as a valid filename.
 851                         * but the latter we have checked in the main loop.
 852                         */
 853                        for (j = i; j < argc; j++)
 854                                verify_filename(revs->prefix, argv[j]);
 855
 856                        revs->prune_data = get_pathspec(revs->prefix, argv + i);
 857                        break;
 858                }
 859                if (!seen_dashdash)
 860                        verify_non_filename(revs->prefix, arg);
 861                object = get_reference(revs, arg, sha1, flags ^ local_flags);
 862                add_pending_object(revs, object, arg);
 863        }
 864        if (def && !revs->pending.nr) {
 865                unsigned char sha1[20];
 866                struct object *object;
 867                if (get_sha1(def, sha1))
 868                        die("bad default revision '%s'", def);
 869                object = get_reference(revs, def, sha1, 0);
 870                add_pending_object(revs, object, def);
 871        }
 872
 873        if (revs->topo_order || revs->unpacked)
 874                revs->limited = 1;
 875
 876        if (revs->prune_data) {
 877                diff_tree_setup_paths(revs->prune_data, &revs->pruning);
 878                revs->prune_fn = try_to_simplify_commit;
 879                if (!revs->full_diff)
 880                        diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
 881        }
 882        if (revs->combine_merges) {
 883                revs->ignore_merges = 0;
 884                if (revs->dense_combined_merges &&
 885                    (revs->diffopt.output_format != DIFF_FORMAT_DIFFSTAT))
 886                        revs->diffopt.output_format = DIFF_FORMAT_PATCH;
 887        }
 888        revs->diffopt.abbrev = revs->abbrev;
 889        diff_setup_done(&revs->diffopt);
 890
 891        return left;
 892}
 893
 894void prepare_revision_walk(struct rev_info *revs)
 895{
 896        int nr = revs->pending.nr;
 897        struct object_array_entry *list = revs->pending.objects;
 898
 899        revs->pending.nr = 0;
 900        revs->pending.alloc = 0;
 901        revs->pending.objects = NULL;
 902        while (--nr >= 0) {
 903                struct commit *commit = handle_commit(revs, list->item, list->name);
 904                if (commit) {
 905                        if (!(commit->object.flags & SEEN)) {
 906                                commit->object.flags |= SEEN;
 907                                insert_by_date(commit, &revs->commits);
 908                        }
 909                }
 910                list++;
 911        }
 912
 913        if (revs->no_walk)
 914                return;
 915        if (revs->limited)
 916                limit_list(revs);
 917        if (revs->topo_order)
 918                sort_in_topological_order_fn(&revs->commits, revs->lifo,
 919                                             revs->topo_setter,
 920                                             revs->topo_getter);
 921}
 922
 923static int rewrite_one(struct rev_info *revs, struct commit **pp)
 924{
 925        for (;;) {
 926                struct commit *p = *pp;
 927                if (!revs->limited)
 928                        add_parents_to_list(revs, p, &revs->commits);
 929                if (p->object.flags & (TREECHANGE | UNINTERESTING))
 930                        return 0;
 931                if (!p->parents)
 932                        return -1;
 933                *pp = p->parents->item;
 934        }
 935}
 936
 937static void rewrite_parents(struct rev_info *revs, struct commit *commit)
 938{
 939        struct commit_list **pp = &commit->parents;
 940        while (*pp) {
 941                struct commit_list *parent = *pp;
 942                if (rewrite_one(revs, &parent->item) < 0) {
 943                        *pp = parent->next;
 944                        continue;
 945                }
 946                pp = &parent->next;
 947        }
 948}
 949
 950static void mark_boundary_to_show(struct commit *commit)
 951{
 952        struct commit_list *p = commit->parents;
 953        while (p) {
 954                commit = p->item;
 955                p = p->next;
 956                if (commit->object.flags & BOUNDARY)
 957                        commit->object.flags |= BOUNDARY_SHOW;
 958        }
 959}
 960
 961struct commit *get_revision(struct rev_info *revs)
 962{
 963        struct commit_list *list = revs->commits;
 964
 965        if (!list)
 966                return NULL;
 967
 968        /* Check the max_count ... */
 969        switch (revs->max_count) {
 970        case -1:
 971                break;
 972        case 0:
 973                return NULL;
 974        default:
 975                revs->max_count--;
 976        }
 977
 978        do {
 979                struct commit_list *entry = revs->commits;
 980                struct commit *commit = entry->item;
 981
 982                revs->commits = entry->next;
 983                free(entry);
 984
 985                /*
 986                 * If we haven't done the list limiting, we need to look at
 987                 * the parents here. We also need to do the date-based limiting
 988                 * that we'd otherwise have done in limit_list().
 989                 */
 990                if (!revs->limited) {
 991                        if ((revs->unpacked &&
 992                             has_sha1_pack(commit->object.sha1)) ||
 993                            (revs->max_age != -1 &&
 994                             (commit->date < revs->max_age)))
 995                                continue;
 996                        add_parents_to_list(revs, commit, &revs->commits);
 997                }
 998                if (commit->object.flags & SHOWN)
 999                        continue;
1000
1001                /* We want to show boundary commits only when their
1002                 * children are shown.  When path-limiter is in effect,
1003                 * rewrite_parents() drops some commits from getting shown,
1004                 * and there is no point showing boundary parents that
1005                 * are not shown.  After rewrite_parents() rewrites the
1006                 * parents of a commit that is shown, we mark the boundary
1007                 * parents with BOUNDARY_SHOW.
1008                 */
1009                if (commit->object.flags & BOUNDARY_SHOW) {
1010                        commit->object.flags |= SHOWN;
1011                        return commit;
1012                }
1013                if (commit->object.flags & UNINTERESTING)
1014                        continue;
1015                if (revs->min_age != -1 && (commit->date > revs->min_age))
1016                        continue;
1017                if (revs->no_merges &&
1018                    commit->parents && commit->parents->next)
1019                        continue;
1020                if (revs->prune_fn && revs->dense) {
1021                        if (!(commit->object.flags & TREECHANGE))
1022                                continue;
1023                        if (revs->parents)
1024                                rewrite_parents(revs, commit);
1025                }
1026                if (revs->boundary)
1027                        mark_boundary_to_show(commit);
1028                commit->object.flags |= SHOWN;
1029                return commit;
1030        } while (revs->commits);
1031        return NULL;
1032}