Andrew's git / gitweb.git / revision.c
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revision.con commit Silence cpio's "N blocks" output when cloning locally (c20711d)
   1#include "cache.h"
   2#include "tag.h"
   3#include "blob.h"
   4#include "tree.h"
   5#include "commit.h"
   6#include "diff.h"
   7#include "refs.h"
   8#include "revision.h"
   9#include "grep.h"
  10#include "reflog-walk.h"
  11#include "patch-ids.h"
  12
  13volatile show_early_output_fn_t show_early_output;
  14
  15static char *path_name(struct name_path *path, const char *name)
  16{
  17        struct name_path *p;
  18        char *n, *m;
  19        int nlen = strlen(name);
  20        int len = nlen + 1;
  21
  22        for (p = path; p; p = p->up) {
  23                if (p->elem_len)
  24                        len += p->elem_len + 1;
  25        }
  26        n = xmalloc(len);
  27        m = n + len - (nlen + 1);
  28        strcpy(m, name);
  29        for (p = path; p; p = p->up) {
  30                if (p->elem_len) {
  31                        m -= p->elem_len + 1;
  32                        memcpy(m, p->elem, p->elem_len);
  33                        m[p->elem_len] = '/';
  34                }
  35        }
  36        return n;
  37}
  38
  39void add_object(struct object *obj,
  40                struct object_array *p,
  41                struct name_path *path,
  42                const char *name)
  43{
  44        add_object_array(obj, path_name(path, name), p);
  45}
  46
  47static void mark_blob_uninteresting(struct blob *blob)
  48{
  49        if (!blob)
  50                return;
  51        if (blob->object.flags & UNINTERESTING)
  52                return;
  53        blob->object.flags |= UNINTERESTING;
  54}
  55
  56void mark_tree_uninteresting(struct tree *tree)
  57{
  58        struct tree_desc desc;
  59        struct name_entry entry;
  60        struct object *obj = &tree->object;
  61
  62        if (!tree)
  63                return;
  64        if (obj->flags & UNINTERESTING)
  65                return;
  66        obj->flags |= UNINTERESTING;
  67        if (!has_sha1_file(obj->sha1))
  68                return;
  69        if (parse_tree(tree) < 0)
  70                die("bad tree %s", sha1_to_hex(obj->sha1));
  71
  72        init_tree_desc(&desc, tree->buffer, tree->size);
  73        while (tree_entry(&desc, &entry)) {
  74                switch (object_type(entry.mode)) {
  75                case OBJ_TREE:
  76                        mark_tree_uninteresting(lookup_tree(entry.sha1));
  77                        break;
  78                case OBJ_BLOB:
  79                        mark_blob_uninteresting(lookup_blob(entry.sha1));
  80                        break;
  81                default:
  82                        /* Subproject commit - not in this repository */
  83                        break;
  84                }
  85        }
  86
  87        /*
  88         * We don't care about the tree any more
  89         * after it has been marked uninteresting.
  90         */
  91        free(tree->buffer);
  92        tree->buffer = NULL;
  93}
  94
  95void mark_parents_uninteresting(struct commit *commit)
  96{
  97        struct commit_list *parents = commit->parents;
  98
  99        while (parents) {
 100                struct commit *commit = parents->item;
 101                if (!(commit->object.flags & UNINTERESTING)) {
 102                        commit->object.flags |= UNINTERESTING;
 103
 104                        /*
 105                         * Normally we haven't parsed the parent
 106                         * yet, so we won't have a parent of a parent
 107                         * here. However, it may turn out that we've
 108                         * reached this commit some other way (where it
 109                         * wasn't uninteresting), in which case we need
 110                         * to mark its parents recursively too..
 111                         */
 112                        if (commit->parents)
 113                                mark_parents_uninteresting(commit);
 114                }
 115
 116                /*
 117                 * A missing commit is ok iff its parent is marked
 118                 * uninteresting.
 119                 *
 120                 * We just mark such a thing parsed, so that when
 121                 * it is popped next time around, we won't be trying
 122                 * to parse it and get an error.
 123                 */
 124                if (!has_sha1_file(commit->object.sha1))
 125                        commit->object.parsed = 1;
 126                parents = parents->next;
 127        }
 128}
 129
 130static void add_pending_object_with_mode(struct rev_info *revs, struct object *obj, const char *name, unsigned mode)
 131{
 132        if (revs->no_walk && (obj->flags & UNINTERESTING))
 133                die("object ranges do not make sense when not walking revisions");
 134        if (revs->reflog_info && obj->type == OBJ_COMMIT &&
 135                        add_reflog_for_walk(revs->reflog_info,
 136                                (struct commit *)obj, name))
 137                return;
 138        add_object_array_with_mode(obj, name, &revs->pending, mode);
 139}
 140
 141void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
 142{
 143        add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
 144}
 145
 146void add_head_to_pending(struct rev_info *revs)
 147{
 148        unsigned char sha1[20];
 149        struct object *obj;
 150        if (get_sha1("HEAD", sha1))
 151                return;
 152        obj = parse_object(sha1);
 153        if (!obj)
 154                return;
 155        add_pending_object(revs, obj, "HEAD");
 156}
 157
 158static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
 159{
 160        struct object *object;
 161
 162        object = parse_object(sha1);
 163        if (!object)
 164                die("bad object %s", name);
 165        object->flags |= flags;
 166        return object;
 167}
 168
 169static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
 170{
 171        unsigned long flags = object->flags;
 172
 173        /*
 174         * Tag object? Look what it points to..
 175         */
 176        while (object->type == OBJ_TAG) {
 177                struct tag *tag = (struct tag *) object;
 178                if (revs->tag_objects && !(flags & UNINTERESTING))
 179                        add_pending_object(revs, object, tag->tag);
 180                if (!tag->tagged)
 181                        die("bad tag");
 182                object = parse_object(tag->tagged->sha1);
 183                if (!object)
 184                        die("bad object %s", sha1_to_hex(tag->tagged->sha1));
 185        }
 186
 187        /*
 188         * Commit object? Just return it, we'll do all the complex
 189         * reachability crud.
 190         */
 191        if (object->type == OBJ_COMMIT) {
 192                struct commit *commit = (struct commit *)object;
 193                if (parse_commit(commit) < 0)
 194                        die("unable to parse commit %s", name);
 195                if (flags & UNINTERESTING) {
 196                        commit->object.flags |= UNINTERESTING;
 197                        mark_parents_uninteresting(commit);
 198                        revs->limited = 1;
 199                }
 200                return commit;
 201        }
 202
 203        /*
 204         * Tree object? Either mark it uniniteresting, or add it
 205         * to the list of objects to look at later..
 206         */
 207        if (object->type == OBJ_TREE) {
 208                struct tree *tree = (struct tree *)object;
 209                if (!revs->tree_objects)
 210                        return NULL;
 211                if (flags & UNINTERESTING) {
 212                        mark_tree_uninteresting(tree);
 213                        return NULL;
 214                }
 215                add_pending_object(revs, object, "");
 216                return NULL;
 217        }
 218
 219        /*
 220         * Blob object? You know the drill by now..
 221         */
 222        if (object->type == OBJ_BLOB) {
 223                struct blob *blob = (struct blob *)object;
 224                if (!revs->blob_objects)
 225                        return NULL;
 226                if (flags & UNINTERESTING) {
 227                        mark_blob_uninteresting(blob);
 228                        return NULL;
 229                }
 230                add_pending_object(revs, object, "");
 231                return NULL;
 232        }
 233        die("%s is unknown object", name);
 234}
 235
 236static int everybody_uninteresting(struct commit_list *orig)
 237{
 238        struct commit_list *list = orig;
 239        while (list) {
 240                struct commit *commit = list->item;
 241                list = list->next;
 242                if (commit->object.flags & UNINTERESTING)
 243                        continue;
 244                return 0;
 245        }
 246        return 1;
 247}
 248
 249/*
 250 * The goal is to get REV_TREE_NEW as the result only if the
 251 * diff consists of all '+' (and no other changes), and
 252 * REV_TREE_DIFFERENT otherwise (of course if the trees are
 253 * the same we want REV_TREE_SAME).  That means that once we
 254 * get to REV_TREE_DIFFERENT, we do not have to look any further.
 255 */
 256static int tree_difference = REV_TREE_SAME;
 257
 258static void file_add_remove(struct diff_options *options,
 259                    int addremove, unsigned mode,
 260                    const unsigned char *sha1,
 261                    const char *base, const char *path)
 262{
 263        int diff = REV_TREE_DIFFERENT;
 264
 265        /*
 266         * Is it an add of a new file? It means that the old tree
 267         * didn't have it at all, so we will turn "REV_TREE_SAME" ->
 268         * "REV_TREE_NEW", but leave any "REV_TREE_DIFFERENT" alone
 269         * (and if it already was "REV_TREE_NEW", we'll keep it
 270         * "REV_TREE_NEW" of course).
 271         */
 272        if (addremove == '+') {
 273                diff = tree_difference;
 274                if (diff != REV_TREE_SAME)
 275                        return;
 276                diff = REV_TREE_NEW;
 277        }
 278        tree_difference = diff;
 279        if (tree_difference == REV_TREE_DIFFERENT)
 280                DIFF_OPT_SET(options, HAS_CHANGES);
 281}
 282
 283static void file_change(struct diff_options *options,
 284                 unsigned old_mode, unsigned new_mode,
 285                 const unsigned char *old_sha1,
 286                 const unsigned char *new_sha1,
 287                 const char *base, const char *path)
 288{
 289        tree_difference = REV_TREE_DIFFERENT;
 290        DIFF_OPT_SET(options, HAS_CHANGES);
 291}
 292
 293static int rev_compare_tree(struct rev_info *revs, struct tree *t1, struct tree *t2)
 294{
 295        if (!t1)
 296                return REV_TREE_NEW;
 297        if (!t2)
 298                return REV_TREE_DIFFERENT;
 299        tree_difference = REV_TREE_SAME;
 300        DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 301        if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
 302                           &revs->pruning) < 0)
 303                return REV_TREE_DIFFERENT;
 304        return tree_difference;
 305}
 306
 307static int rev_same_tree_as_empty(struct rev_info *revs, struct tree *t1)
 308{
 309        int retval;
 310        void *tree;
 311        unsigned long size;
 312        struct tree_desc empty, real;
 313
 314        if (!t1)
 315                return 0;
 316
 317        tree = read_object_with_reference(t1->object.sha1, tree_type, &size, NULL);
 318        if (!tree)
 319                return 0;
 320        init_tree_desc(&real, tree, size);
 321        init_tree_desc(&empty, "", 0);
 322
 323        tree_difference = REV_TREE_SAME;
 324        DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 325        retval = diff_tree(&empty, &real, "", &revs->pruning);
 326        free(tree);
 327
 328        return retval >= 0 && (tree_difference == REV_TREE_SAME);
 329}
 330
 331static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 332{
 333        struct commit_list **pp, *parent;
 334        int tree_changed = 0, tree_same = 0;
 335
 336        /*
 337         * If we don't do pruning, everything is interesting
 338         */
 339        if (!revs->prune)
 340                return;
 341
 342        if (!commit->tree)
 343                return;
 344
 345        if (!commit->parents) {
 346                if (rev_same_tree_as_empty(revs, commit->tree))
 347                        commit->object.flags |= TREESAME;
 348                return;
 349        }
 350
 351        /*
 352         * Normal non-merge commit? If we don't want to make the
 353         * history dense, we consider it always to be a change..
 354         */
 355        if (!revs->dense && !commit->parents->next)
 356                return;
 357
 358        pp = &commit->parents;
 359        while ((parent = *pp) != NULL) {
 360                struct commit *p = parent->item;
 361
 362                if (parse_commit(p) < 0)
 363                        die("cannot simplify commit %s (because of %s)",
 364                            sha1_to_hex(commit->object.sha1),
 365                            sha1_to_hex(p->object.sha1));
 366                switch (rev_compare_tree(revs, p->tree, commit->tree)) {
 367                case REV_TREE_SAME:
 368                        tree_same = 1;
 369                        if (!revs->simplify_history || (p->object.flags & UNINTERESTING)) {
 370                                /* Even if a merge with an uninteresting
 371                                 * side branch brought the entire change
 372                                 * we are interested in, we do not want
 373                                 * to lose the other branches of this
 374                                 * merge, so we just keep going.
 375                                 */
 376                                pp = &parent->next;
 377                                continue;
 378                        }
 379                        parent->next = NULL;
 380                        commit->parents = parent;
 381                        commit->object.flags |= TREESAME;
 382                        return;
 383
 384                case REV_TREE_NEW:
 385                        if (revs->remove_empty_trees &&
 386                            rev_same_tree_as_empty(revs, p->tree)) {
 387                                /* We are adding all the specified
 388                                 * paths from this parent, so the
 389                                 * history beyond this parent is not
 390                                 * interesting.  Remove its parents
 391                                 * (they are grandparents for us).
 392                                 * IOW, we pretend this parent is a
 393                                 * "root" commit.
 394                                 */
 395                                if (parse_commit(p) < 0)
 396                                        die("cannot simplify commit %s (invalid %s)",
 397                                            sha1_to_hex(commit->object.sha1),
 398                                            sha1_to_hex(p->object.sha1));
 399                                p->parents = NULL;
 400                        }
 401                /* fallthrough */
 402                case REV_TREE_DIFFERENT:
 403                        tree_changed = 1;
 404                        pp = &parent->next;
 405                        continue;
 406                }
 407                die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
 408        }
 409        if (tree_changed && !tree_same)
 410                return;
 411        commit->object.flags |= TREESAME;
 412}
 413
 414static int add_parents_to_list(struct rev_info *revs, struct commit *commit, struct commit_list **list)
 415{
 416        struct commit_list *parent = commit->parents;
 417        unsigned left_flag;
 418        int add, rest;
 419
 420        if (commit->object.flags & ADDED)
 421                return 0;
 422        commit->object.flags |= ADDED;
 423
 424        /*
 425         * If the commit is uninteresting, don't try to
 426         * prune parents - we want the maximal uninteresting
 427         * set.
 428         *
 429         * Normally we haven't parsed the parent
 430         * yet, so we won't have a parent of a parent
 431         * here. However, it may turn out that we've
 432         * reached this commit some other way (where it
 433         * wasn't uninteresting), in which case we need
 434         * to mark its parents recursively too..
 435         */
 436        if (commit->object.flags & UNINTERESTING) {
 437                while (parent) {
 438                        struct commit *p = parent->item;
 439                        parent = parent->next;
 440                        if (parse_commit(p) < 0)
 441                                return -1;
 442                        p->object.flags |= UNINTERESTING;
 443                        if (p->parents)
 444                                mark_parents_uninteresting(p);
 445                        if (p->object.flags & SEEN)
 446                                continue;
 447                        p->object.flags |= SEEN;
 448                        insert_by_date(p, list);
 449                }
 450                return 0;
 451        }
 452
 453        /*
 454         * Ok, the commit wasn't uninteresting. Try to
 455         * simplify the commit history and find the parent
 456         * that has no differences in the path set if one exists.
 457         */
 458        try_to_simplify_commit(revs, commit);
 459
 460        if (revs->no_walk)
 461                return 0;
 462
 463        left_flag = (commit->object.flags & SYMMETRIC_LEFT);
 464
 465        rest = !revs->first_parent_only;
 466        for (parent = commit->parents, add = 1; parent; add = rest) {
 467                struct commit *p = parent->item;
 468
 469                parent = parent->next;
 470                if (parse_commit(p) < 0)
 471                        return -1;
 472                p->object.flags |= left_flag;
 473                if (p->object.flags & SEEN)
 474                        continue;
 475                p->object.flags |= SEEN;
 476                if (add)
 477                        insert_by_date(p, list);
 478        }
 479        return 0;
 480}
 481
 482static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
 483{
 484        struct commit_list *p;
 485        int left_count = 0, right_count = 0;
 486        int left_first;
 487        struct patch_ids ids;
 488
 489        /* First count the commits on the left and on the right */
 490        for (p = list; p; p = p->next) {
 491                struct commit *commit = p->item;
 492                unsigned flags = commit->object.flags;
 493                if (flags & BOUNDARY)
 494                        ;
 495                else if (flags & SYMMETRIC_LEFT)
 496                        left_count++;
 497                else
 498                        right_count++;
 499        }
 500
 501        left_first = left_count < right_count;
 502        init_patch_ids(&ids);
 503        if (revs->diffopt.nr_paths) {
 504                ids.diffopts.nr_paths = revs->diffopt.nr_paths;
 505                ids.diffopts.paths = revs->diffopt.paths;
 506                ids.diffopts.pathlens = revs->diffopt.pathlens;
 507        }
 508
 509        /* Compute patch-ids for one side */
 510        for (p = list; p; p = p->next) {
 511                struct commit *commit = p->item;
 512                unsigned flags = commit->object.flags;
 513
 514                if (flags & BOUNDARY)
 515                        continue;
 516                /*
 517                 * If we have fewer left, left_first is set and we omit
 518                 * commits on the right branch in this loop.  If we have
 519                 * fewer right, we skip the left ones.
 520                 */
 521                if (left_first != !!(flags & SYMMETRIC_LEFT))
 522                        continue;
 523                commit->util = add_commit_patch_id(commit, &ids);
 524        }
 525
 526        /* Check the other side */
 527        for (p = list; p; p = p->next) {
 528                struct commit *commit = p->item;
 529                struct patch_id *id;
 530                unsigned flags = commit->object.flags;
 531
 532                if (flags & BOUNDARY)
 533                        continue;
 534                /*
 535                 * If we have fewer left, left_first is set and we omit
 536                 * commits on the left branch in this loop.
 537                 */
 538                if (left_first == !!(flags & SYMMETRIC_LEFT))
 539                        continue;
 540
 541                /*
 542                 * Have we seen the same patch id?
 543                 */
 544                id = has_commit_patch_id(commit, &ids);
 545                if (!id)
 546                        continue;
 547                id->seen = 1;
 548                commit->object.flags |= SHOWN;
 549        }
 550
 551        /* Now check the original side for seen ones */
 552        for (p = list; p; p = p->next) {
 553                struct commit *commit = p->item;
 554                struct patch_id *ent;
 555
 556                ent = commit->util;
 557                if (!ent)
 558                        continue;
 559                if (ent->seen)
 560                        commit->object.flags |= SHOWN;
 561                commit->util = NULL;
 562        }
 563
 564        free_patch_ids(&ids);
 565}
 566
 567/* How many extra uninteresting commits we want to see.. */
 568#define SLOP 5
 569
 570static int still_interesting(struct commit_list *src, unsigned long date, int slop)
 571{
 572        /*
 573         * No source list at all? We're definitely done..
 574         */
 575        if (!src)
 576                return 0;
 577
 578        /*
 579         * Does the destination list contain entries with a date
 580         * before the source list? Definitely _not_ done.
 581         */
 582        if (date < src->item->date)
 583                return SLOP;
 584
 585        /*
 586         * Does the source list still have interesting commits in
 587         * it? Definitely not done..
 588         */
 589        if (!everybody_uninteresting(src))
 590                return SLOP;
 591
 592        /* Ok, we're closing in.. */
 593        return slop-1;
 594}
 595
 596static int limit_list(struct rev_info *revs)
 597{
 598        int slop = SLOP;
 599        unsigned long date = ~0ul;
 600        struct commit_list *list = revs->commits;
 601        struct commit_list *newlist = NULL;
 602        struct commit_list **p = &newlist;
 603
 604        while (list) {
 605                struct commit_list *entry = list;
 606                struct commit *commit = list->item;
 607                struct object *obj = &commit->object;
 608                show_early_output_fn_t show;
 609
 610                list = list->next;
 611                free(entry);
 612
 613                if (revs->max_age != -1 && (commit->date < revs->max_age))
 614                        obj->flags |= UNINTERESTING;
 615                if (add_parents_to_list(revs, commit, &list) < 0)
 616                        return -1;
 617                if (obj->flags & UNINTERESTING) {
 618                        mark_parents_uninteresting(commit);
 619                        if (revs->show_all)
 620                                p = &commit_list_insert(commit, p)->next;
 621                        slop = still_interesting(list, date, slop);
 622                        if (slop)
 623                                continue;
 624                        /* If showing all, add the whole pending list to the end */
 625                        if (revs->show_all)
 626                                *p = list;
 627                        break;
 628                }
 629                if (revs->min_age != -1 && (commit->date > revs->min_age))
 630                        continue;
 631                date = commit->date;
 632                p = &commit_list_insert(commit, p)->next;
 633
 634                show = show_early_output;
 635                if (!show)
 636                        continue;
 637
 638                show(revs, newlist);
 639                show_early_output = NULL;
 640        }
 641        if (revs->cherry_pick)
 642                cherry_pick_list(newlist, revs);
 643
 644        revs->commits = newlist;
 645        return 0;
 646}
 647
 648struct all_refs_cb {
 649        int all_flags;
 650        int warned_bad_reflog;
 651        struct rev_info *all_revs;
 652        const char *name_for_errormsg;
 653};
 654
 655static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 656{
 657        struct all_refs_cb *cb = cb_data;
 658        struct object *object = get_reference(cb->all_revs, path, sha1,
 659                                              cb->all_flags);
 660        add_pending_object(cb->all_revs, object, path);
 661        return 0;
 662}
 663
 664static void handle_refs(struct rev_info *revs, unsigned flags,
 665                int (*for_each)(each_ref_fn, void *))
 666{
 667        struct all_refs_cb cb;
 668        cb.all_revs = revs;
 669        cb.all_flags = flags;
 670        for_each(handle_one_ref, &cb);
 671}
 672
 673static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
 674{
 675        struct all_refs_cb *cb = cb_data;
 676        if (!is_null_sha1(sha1)) {
 677                struct object *o = parse_object(sha1);
 678                if (o) {
 679                        o->flags |= cb->all_flags;
 680                        add_pending_object(cb->all_revs, o, "");
 681                }
 682                else if (!cb->warned_bad_reflog) {
 683                        warning("reflog of '%s' references pruned commits",
 684                                cb->name_for_errormsg);
 685                        cb->warned_bad_reflog = 1;
 686                }
 687        }
 688}
 689
 690static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 691                const char *email, unsigned long timestamp, int tz,
 692                const char *message, void *cb_data)
 693{
 694        handle_one_reflog_commit(osha1, cb_data);
 695        handle_one_reflog_commit(nsha1, cb_data);
 696        return 0;
 697}
 698
 699static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 700{
 701        struct all_refs_cb *cb = cb_data;
 702        cb->warned_bad_reflog = 0;
 703        cb->name_for_errormsg = path;
 704        for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
 705        return 0;
 706}
 707
 708static void handle_reflog(struct rev_info *revs, unsigned flags)
 709{
 710        struct all_refs_cb cb;
 711        cb.all_revs = revs;
 712        cb.all_flags = flags;
 713        for_each_reflog(handle_one_reflog, &cb);
 714}
 715
 716static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
 717{
 718        unsigned char sha1[20];
 719        struct object *it;
 720        struct commit *commit;
 721        struct commit_list *parents;
 722
 723        if (*arg == '^') {
 724                flags ^= UNINTERESTING;
 725                arg++;
 726        }
 727        if (get_sha1(arg, sha1))
 728                return 0;
 729        while (1) {
 730                it = get_reference(revs, arg, sha1, 0);
 731                if (it->type != OBJ_TAG)
 732                        break;
 733                if (!((struct tag*)it)->tagged)
 734                        return 0;
 735                hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
 736        }
 737        if (it->type != OBJ_COMMIT)
 738                return 0;
 739        commit = (struct commit *)it;
 740        for (parents = commit->parents; parents; parents = parents->next) {
 741                it = &parents->item->object;
 742                it->flags |= flags;
 743                add_pending_object(revs, it, arg);
 744        }
 745        return 1;
 746}
 747
 748void init_revisions(struct rev_info *revs, const char *prefix)
 749{
 750        memset(revs, 0, sizeof(*revs));
 751
 752        revs->abbrev = DEFAULT_ABBREV;
 753        revs->ignore_merges = 1;
 754        revs->simplify_history = 1;
 755        DIFF_OPT_SET(&revs->pruning, RECURSIVE);
 756        DIFF_OPT_SET(&revs->pruning, QUIET);
 757        revs->pruning.add_remove = file_add_remove;
 758        revs->pruning.change = file_change;
 759        revs->lifo = 1;
 760        revs->dense = 1;
 761        revs->prefix = prefix;
 762        revs->max_age = -1;
 763        revs->min_age = -1;
 764        revs->skip_count = -1;
 765        revs->max_count = -1;
 766
 767        revs->commit_format = CMIT_FMT_DEFAULT;
 768
 769        diff_setup(&revs->diffopt);
 770        if (prefix && !revs->diffopt.prefix) {
 771                revs->diffopt.prefix = prefix;
 772                revs->diffopt.prefix_length = strlen(prefix);
 773        }
 774}
 775
 776static void add_pending_commit_list(struct rev_info *revs,
 777                                    struct commit_list *commit_list,
 778                                    unsigned int flags)
 779{
 780        while (commit_list) {
 781                struct object *object = &commit_list->item->object;
 782                object->flags |= flags;
 783                add_pending_object(revs, object, sha1_to_hex(object->sha1));
 784                commit_list = commit_list->next;
 785        }
 786}
 787
 788static void prepare_show_merge(struct rev_info *revs)
 789{
 790        struct commit_list *bases;
 791        struct commit *head, *other;
 792        unsigned char sha1[20];
 793        const char **prune = NULL;
 794        int i, prune_num = 1; /* counting terminating NULL */
 795
 796        if (get_sha1("HEAD", sha1) || !(head = lookup_commit(sha1)))
 797                die("--merge without HEAD?");
 798        if (get_sha1("MERGE_HEAD", sha1) || !(other = lookup_commit(sha1)))
 799                die("--merge without MERGE_HEAD?");
 800        add_pending_object(revs, &head->object, "HEAD");
 801        add_pending_object(revs, &other->object, "MERGE_HEAD");
 802        bases = get_merge_bases(head, other, 1);
 803        add_pending_commit_list(revs, bases, UNINTERESTING);
 804        free_commit_list(bases);
 805        head->object.flags |= SYMMETRIC_LEFT;
 806
 807        if (!active_nr)
 808                read_cache();
 809        for (i = 0; i < active_nr; i++) {
 810                struct cache_entry *ce = active_cache[i];
 811                if (!ce_stage(ce))
 812                        continue;
 813                if (ce_path_match(ce, revs->prune_data)) {
 814                        prune_num++;
 815                        prune = xrealloc(prune, sizeof(*prune) * prune_num);
 816                        prune[prune_num-2] = ce->name;
 817                        prune[prune_num-1] = NULL;
 818                }
 819                while ((i+1 < active_nr) &&
 820                       ce_same_name(ce, active_cache[i+1]))
 821                        i++;
 822        }
 823        revs->prune_data = prune;
 824        revs->limited = 1;
 825}
 826
 827int handle_revision_arg(const char *arg, struct rev_info *revs,
 828                        int flags,
 829                        int cant_be_filename)
 830{
 831        unsigned mode;
 832        char *dotdot;
 833        struct object *object;
 834        unsigned char sha1[20];
 835        int local_flags;
 836
 837        dotdot = strstr(arg, "..");
 838        if (dotdot) {
 839                unsigned char from_sha1[20];
 840                const char *next = dotdot + 2;
 841                const char *this = arg;
 842                int symmetric = *next == '.';
 843                unsigned int flags_exclude = flags ^ UNINTERESTING;
 844
 845                *dotdot = 0;
 846                next += symmetric;
 847
 848                if (!*next)
 849                        next = "HEAD";
 850                if (dotdot == arg)
 851                        this = "HEAD";
 852                if (!get_sha1(this, from_sha1) &&
 853                    !get_sha1(next, sha1)) {
 854                        struct commit *a, *b;
 855                        struct commit_list *exclude;
 856
 857                        a = lookup_commit_reference(from_sha1);
 858                        b = lookup_commit_reference(sha1);
 859                        if (!a || !b) {
 860                                die(symmetric ?
 861                                    "Invalid symmetric difference expression %s...%s" :
 862                                    "Invalid revision range %s..%s",
 863                                    arg, next);
 864                        }
 865
 866                        if (!cant_be_filename) {
 867                                *dotdot = '.';
 868                                verify_non_filename(revs->prefix, arg);
 869                        }
 870
 871                        if (symmetric) {
 872                                exclude = get_merge_bases(a, b, 1);
 873                                add_pending_commit_list(revs, exclude,
 874                                                        flags_exclude);
 875                                free_commit_list(exclude);
 876                                a->object.flags |= flags | SYMMETRIC_LEFT;
 877                        } else
 878                                a->object.flags |= flags_exclude;
 879                        b->object.flags |= flags;
 880                        add_pending_object(revs, &a->object, this);
 881                        add_pending_object(revs, &b->object, next);
 882                        return 0;
 883                }
 884                *dotdot = '.';
 885        }
 886        dotdot = strstr(arg, "^@");
 887        if (dotdot && !dotdot[2]) {
 888                *dotdot = 0;
 889                if (add_parents_only(revs, arg, flags))
 890                        return 0;
 891                *dotdot = '^';
 892        }
 893        dotdot = strstr(arg, "^!");
 894        if (dotdot && !dotdot[2]) {
 895                *dotdot = 0;
 896                if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
 897                        *dotdot = '^';
 898        }
 899
 900        local_flags = 0;
 901        if (*arg == '^') {
 902                local_flags = UNINTERESTING;
 903                arg++;
 904        }
 905        if (get_sha1_with_mode(arg, sha1, &mode))
 906                return -1;
 907        if (!cant_be_filename)
 908                verify_non_filename(revs->prefix, arg);
 909        object = get_reference(revs, arg, sha1, flags ^ local_flags);
 910        add_pending_object_with_mode(revs, object, arg, mode);
 911        return 0;
 912}
 913
 914static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
 915{
 916        if (!revs->grep_filter) {
 917                struct grep_opt *opt = xcalloc(1, sizeof(*opt));
 918                opt->status_only = 1;
 919                opt->pattern_tail = &(opt->pattern_list);
 920                opt->regflags = REG_NEWLINE;
 921                revs->grep_filter = opt;
 922        }
 923        append_grep_pattern(revs->grep_filter, ptn,
 924                            "command line", 0, what);
 925}
 926
 927static void add_header_grep(struct rev_info *revs, const char *field, const char *pattern)
 928{
 929        char *pat;
 930        const char *prefix;
 931        int patlen, fldlen;
 932
 933        fldlen = strlen(field);
 934        patlen = strlen(pattern);
 935        pat = xmalloc(patlen + fldlen + 10);
 936        prefix = ".*";
 937        if (*pattern == '^') {
 938                prefix = "";
 939                pattern++;
 940        }
 941        sprintf(pat, "^%s %s%s", field, prefix, pattern);
 942        add_grep(revs, pat, GREP_PATTERN_HEAD);
 943}
 944
 945static void add_message_grep(struct rev_info *revs, const char *pattern)
 946{
 947        add_grep(revs, pattern, GREP_PATTERN_BODY);
 948}
 949
 950static void add_ignore_packed(struct rev_info *revs, const char *name)
 951{
 952        int num = ++revs->num_ignore_packed;
 953
 954        revs->ignore_packed = xrealloc(revs->ignore_packed,
 955                                       sizeof(const char **) * (num + 1));
 956        revs->ignore_packed[num-1] = name;
 957        revs->ignore_packed[num] = NULL;
 958}
 959
 960/*
 961 * Parse revision information, filling in the "rev_info" structure,
 962 * and removing the used arguments from the argument list.
 963 *
 964 * Returns the number of arguments left that weren't recognized
 965 * (which are also moved to the head of the argument list)
 966 */
 967int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
 968{
 969        int i, flags, seen_dashdash, show_merge;
 970        const char **unrecognized = argv + 1;
 971        int left = 1;
 972        int all_match = 0;
 973        int regflags = 0;
 974        int fixed = 0;
 975
 976        /* First, search for "--" */
 977        seen_dashdash = 0;
 978        for (i = 1; i < argc; i++) {
 979                const char *arg = argv[i];
 980                if (strcmp(arg, "--"))
 981                        continue;
 982                argv[i] = NULL;
 983                argc = i;
 984                if (argv[i + 1])
 985                        revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
 986                seen_dashdash = 1;
 987                break;
 988        }
 989
 990        flags = show_merge = 0;
 991        for (i = 1; i < argc; i++) {
 992                const char *arg = argv[i];
 993                if (*arg == '-') {
 994                        int opts;
 995                        if (!prefixcmp(arg, "--max-count=")) {
 996                                revs->max_count = atoi(arg + 12);
 997                                continue;
 998                        }
 999                        if (!prefixcmp(arg, "--skip=")) {
1000                                revs->skip_count = atoi(arg + 7);
1001                                continue;
1002                        }
1003                        /* accept -<digit>, like traditional "head" */
1004                        if ((*arg == '-') && isdigit(arg[1])) {
1005                                revs->max_count = atoi(arg + 1);
1006                                continue;
1007                        }
1008                        if (!strcmp(arg, "-n")) {
1009                                if (argc <= i + 1)
1010                                        die("-n requires an argument");
1011                                revs->max_count = atoi(argv[++i]);
1012                                continue;
1013                        }
1014                        if (!prefixcmp(arg, "-n")) {
1015                                revs->max_count = atoi(arg + 2);
1016                                continue;
1017                        }
1018                        if (!prefixcmp(arg, "--max-age=")) {
1019                                revs->max_age = atoi(arg + 10);
1020                                continue;
1021                        }
1022                        if (!prefixcmp(arg, "--since=")) {
1023                                revs->max_age = approxidate(arg + 8);
1024                                continue;
1025                        }
1026                        if (!prefixcmp(arg, "--after=")) {
1027                                revs->max_age = approxidate(arg + 8);
1028                                continue;
1029                        }
1030                        if (!prefixcmp(arg, "--min-age=")) {
1031                                revs->min_age = atoi(arg + 10);
1032                                continue;
1033                        }
1034                        if (!prefixcmp(arg, "--before=")) {
1035                                revs->min_age = approxidate(arg + 9);
1036                                continue;
1037                        }
1038                        if (!prefixcmp(arg, "--until=")) {
1039                                revs->min_age = approxidate(arg + 8);
1040                                continue;
1041                        }
1042                        if (!strcmp(arg, "--all")) {
1043                                handle_refs(revs, flags, for_each_ref);
1044                                continue;
1045                        }
1046                        if (!strcmp(arg, "--branches")) {
1047                                handle_refs(revs, flags, for_each_branch_ref);
1048                                continue;
1049                        }
1050                        if (!strcmp(arg, "--tags")) {
1051                                handle_refs(revs, flags, for_each_tag_ref);
1052                                continue;
1053                        }
1054                        if (!strcmp(arg, "--remotes")) {
1055                                handle_refs(revs, flags, for_each_remote_ref);
1056                                continue;
1057                        }
1058                        if (!strcmp(arg, "--first-parent")) {
1059                                revs->first_parent_only = 1;
1060                                continue;
1061                        }
1062                        if (!strcmp(arg, "--reflog")) {
1063                                handle_reflog(revs, flags);
1064                                continue;
1065                        }
1066                        if (!strcmp(arg, "-g") ||
1067                                        !strcmp(arg, "--walk-reflogs")) {
1068                                init_reflog_walk(&revs->reflog_info);
1069                                continue;
1070                        }
1071                        if (!strcmp(arg, "--not")) {
1072                                flags ^= UNINTERESTING;
1073                                continue;
1074                        }
1075                        if (!strcmp(arg, "--default")) {
1076                                if (++i >= argc)
1077                                        die("bad --default argument");
1078                                def = argv[i];
1079                                continue;
1080                        }
1081                        if (!strcmp(arg, "--merge")) {
1082                                show_merge = 1;
1083                                continue;
1084                        }
1085                        if (!strcmp(arg, "--topo-order")) {
1086                                revs->topo_order = 1;
1087                                continue;
1088                        }
1089                        if (!strcmp(arg, "--date-order")) {
1090                                revs->lifo = 0;
1091                                revs->topo_order = 1;
1092                                continue;
1093                        }
1094                        if (!prefixcmp(arg, "--early-output")) {
1095                                int count = 100;
1096                                switch (arg[14]) {
1097                                case '=':
1098                                        count = atoi(arg+15);
1099                                        /* Fallthrough */
1100                                case 0:
1101                                        revs->topo_order = 1;
1102                                        revs->early_output = count;
1103                                        continue;
1104                                }
1105                        }
1106                        if (!strcmp(arg, "--parents")) {
1107                                revs->parents = 1;
1108                                continue;
1109                        }
1110                        if (!strcmp(arg, "--dense")) {
1111                                revs->dense = 1;
1112                                continue;
1113                        }
1114                        if (!strcmp(arg, "--sparse")) {
1115                                revs->dense = 0;
1116                                continue;
1117                        }
1118                        if (!strcmp(arg, "--show-all")) {
1119                                revs->show_all = 1;
1120                                continue;
1121                        }
1122                        if (!strcmp(arg, "--remove-empty")) {
1123                                revs->remove_empty_trees = 1;
1124                                continue;
1125                        }
1126                        if (!strcmp(arg, "--no-merges")) {
1127                                revs->no_merges = 1;
1128                                continue;
1129                        }
1130                        if (!strcmp(arg, "--boundary")) {
1131                                revs->boundary = 1;
1132                                continue;
1133                        }
1134                        if (!strcmp(arg, "--left-right")) {
1135                                revs->left_right = 1;
1136                                continue;
1137                        }
1138                        if (!strcmp(arg, "--cherry-pick")) {
1139                                revs->cherry_pick = 1;
1140                                revs->limited = 1;
1141                                continue;
1142                        }
1143                        if (!strcmp(arg, "--objects")) {
1144                                revs->tag_objects = 1;
1145                                revs->tree_objects = 1;
1146                                revs->blob_objects = 1;
1147                                continue;
1148                        }
1149                        if (!strcmp(arg, "--objects-edge")) {
1150                                revs->tag_objects = 1;
1151                                revs->tree_objects = 1;
1152                                revs->blob_objects = 1;
1153                                revs->edge_hint = 1;
1154                                continue;
1155                        }
1156                        if (!strcmp(arg, "--unpacked")) {
1157                                revs->unpacked = 1;
1158                                free(revs->ignore_packed);
1159                                revs->ignore_packed = NULL;
1160                                revs->num_ignore_packed = 0;
1161                                continue;
1162                        }
1163                        if (!prefixcmp(arg, "--unpacked=")) {
1164                                revs->unpacked = 1;
1165                                add_ignore_packed(revs, arg+11);
1166                                continue;
1167                        }
1168                        if (!strcmp(arg, "-r")) {
1169                                revs->diff = 1;
1170                                DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1171                                continue;
1172                        }
1173                        if (!strcmp(arg, "-t")) {
1174                                revs->diff = 1;
1175                                DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1176                                DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1177                                continue;
1178                        }
1179                        if (!strcmp(arg, "-m")) {
1180                                revs->ignore_merges = 0;
1181                                continue;
1182                        }
1183                        if (!strcmp(arg, "-c")) {
1184                                revs->diff = 1;
1185                                revs->dense_combined_merges = 0;
1186                                revs->combine_merges = 1;
1187                                continue;
1188                        }
1189                        if (!strcmp(arg, "--cc")) {
1190                                revs->diff = 1;
1191                                revs->dense_combined_merges = 1;
1192                                revs->combine_merges = 1;
1193                                continue;
1194                        }
1195                        if (!strcmp(arg, "-v")) {
1196                                revs->verbose_header = 1;
1197                                continue;
1198                        }
1199                        if (!prefixcmp(arg, "--pretty")) {
1200                                revs->verbose_header = 1;
1201                                revs->commit_format = get_commit_format(arg+8);
1202                                continue;
1203                        }
1204                        if (!strcmp(arg, "--root")) {
1205                                revs->show_root_diff = 1;
1206                                continue;
1207                        }
1208                        if (!strcmp(arg, "--no-commit-id")) {
1209                                revs->no_commit_id = 1;
1210                                continue;
1211                        }
1212                        if (!strcmp(arg, "--always")) {
1213                                revs->always_show_header = 1;
1214                                continue;
1215                        }
1216                        if (!strcmp(arg, "--no-abbrev")) {
1217                                revs->abbrev = 0;
1218                                continue;
1219                        }
1220                        if (!strcmp(arg, "--abbrev")) {
1221                                revs->abbrev = DEFAULT_ABBREV;
1222                                continue;
1223                        }
1224                        if (!prefixcmp(arg, "--abbrev=")) {
1225                                revs->abbrev = strtoul(arg + 9, NULL, 10);
1226                                if (revs->abbrev < MINIMUM_ABBREV)
1227                                        revs->abbrev = MINIMUM_ABBREV;
1228                                else if (revs->abbrev > 40)
1229                                        revs->abbrev = 40;
1230                                continue;
1231                        }
1232                        if (!strcmp(arg, "--abbrev-commit")) {
1233                                revs->abbrev_commit = 1;
1234                                continue;
1235                        }
1236                        if (!strcmp(arg, "--full-diff")) {
1237                                revs->diff = 1;
1238                                revs->full_diff = 1;
1239                                continue;
1240                        }
1241                        if (!strcmp(arg, "--full-history")) {
1242                                revs->simplify_history = 0;
1243                                continue;
1244                        }
1245                        if (!strcmp(arg, "--relative-date")) {
1246                                revs->date_mode = DATE_RELATIVE;
1247                                continue;
1248                        }
1249                        if (!strncmp(arg, "--date=", 7)) {
1250                                revs->date_mode = parse_date_format(arg + 7);
1251                                continue;
1252                        }
1253                        if (!strcmp(arg, "--log-size")) {
1254                                revs->show_log_size = 1;
1255                                continue;
1256                        }
1257
1258                        /*
1259                         * Grepping the commit log
1260                         */
1261                        if (!prefixcmp(arg, "--author=")) {
1262                                add_header_grep(revs, "author", arg+9);
1263                                continue;
1264                        }
1265                        if (!prefixcmp(arg, "--committer=")) {
1266                                add_header_grep(revs, "committer", arg+12);
1267                                continue;
1268                        }
1269                        if (!prefixcmp(arg, "--grep=")) {
1270                                add_message_grep(revs, arg+7);
1271                                continue;
1272                        }
1273                        if (!strcmp(arg, "--extended-regexp") ||
1274                            !strcmp(arg, "-E")) {
1275                                regflags |= REG_EXTENDED;
1276                                continue;
1277                        }
1278                        if (!strcmp(arg, "--regexp-ignore-case") ||
1279                            !strcmp(arg, "-i")) {
1280                                regflags |= REG_ICASE;
1281                                continue;
1282                        }
1283                        if (!strcmp(arg, "--fixed-strings") ||
1284                            !strcmp(arg, "-F")) {
1285                                fixed = 1;
1286                                continue;
1287                        }
1288                        if (!strcmp(arg, "--all-match")) {
1289                                all_match = 1;
1290                                continue;
1291                        }
1292                        if (!prefixcmp(arg, "--encoding=")) {
1293                                arg += 11;
1294                                if (strcmp(arg, "none"))
1295                                        git_log_output_encoding = xstrdup(arg);
1296                                else
1297                                        git_log_output_encoding = "";
1298                                continue;
1299                        }
1300                        if (!strcmp(arg, "--reverse")) {
1301                                revs->reverse ^= 1;
1302                                continue;
1303                        }
1304                        if (!strcmp(arg, "--no-walk")) {
1305                                revs->no_walk = 1;
1306                                continue;
1307                        }
1308                        if (!strcmp(arg, "--do-walk")) {
1309                                revs->no_walk = 0;
1310                                continue;
1311                        }
1312
1313                        opts = diff_opt_parse(&revs->diffopt, argv+i, argc-i);
1314                        if (opts > 0) {
1315                                i += opts - 1;
1316                                continue;
1317                        }
1318                        *unrecognized++ = arg;
1319                        left++;
1320                        continue;
1321                }
1322
1323                if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
1324                        int j;
1325                        if (seen_dashdash || *arg == '^')
1326                                die("bad revision '%s'", arg);
1327
1328                        /* If we didn't have a "--":
1329                         * (1) all filenames must exist;
1330                         * (2) all rev-args must not be interpretable
1331                         *     as a valid filename.
1332                         * but the latter we have checked in the main loop.
1333                         */
1334                        for (j = i; j < argc; j++)
1335                                verify_filename(revs->prefix, argv[j]);
1336
1337                        revs->prune_data = get_pathspec(revs->prefix,
1338                                                        argv + i);
1339                        break;
1340                }
1341        }
1342
1343        if (revs->grep_filter) {
1344                revs->grep_filter->regflags |= regflags;
1345                revs->grep_filter->fixed = fixed;
1346        }
1347
1348        if (show_merge)
1349                prepare_show_merge(revs);
1350        if (def && !revs->pending.nr) {
1351                unsigned char sha1[20];
1352                struct object *object;
1353                unsigned mode;
1354                if (get_sha1_with_mode(def, sha1, &mode))
1355                        die("bad default revision '%s'", def);
1356                object = get_reference(revs, def, sha1, 0);
1357                add_pending_object_with_mode(revs, object, def, mode);
1358        }
1359
1360        /* Did the user ask for any diff output? Run the diff! */
1361        if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
1362                revs->diff = 1;
1363
1364        /* Pickaxe, diff-filter and rename following need diffs */
1365        if (revs->diffopt.pickaxe ||
1366            revs->diffopt.filter ||
1367            DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1368                revs->diff = 1;
1369
1370        if (revs->topo_order)
1371                revs->limited = 1;
1372
1373        if (revs->prune_data) {
1374                diff_tree_setup_paths(revs->prune_data, &revs->pruning);
1375                /* Can't prune commits with rename following: the paths change.. */
1376                if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1377                        revs->prune = 1;
1378                if (!revs->full_diff)
1379                        diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
1380        }
1381        if (revs->combine_merges) {
1382                revs->ignore_merges = 0;
1383                if (revs->dense_combined_merges && !revs->diffopt.output_format)
1384                        revs->diffopt.output_format = DIFF_FORMAT_PATCH;
1385        }
1386        revs->diffopt.abbrev = revs->abbrev;
1387        if (diff_setup_done(&revs->diffopt) < 0)
1388                die("diff_setup_done failed");
1389
1390        if (revs->grep_filter) {
1391                revs->grep_filter->all_match = all_match;
1392                compile_grep_patterns(revs->grep_filter);
1393        }
1394
1395        if (revs->reverse && revs->reflog_info)
1396                die("cannot combine --reverse with --walk-reflogs");
1397
1398        return left;
1399}
1400
1401int prepare_revision_walk(struct rev_info *revs)
1402{
1403        int nr = revs->pending.nr;
1404        struct object_array_entry *e, *list;
1405
1406        e = list = revs->pending.objects;
1407        revs->pending.nr = 0;
1408        revs->pending.alloc = 0;
1409        revs->pending.objects = NULL;
1410        while (--nr >= 0) {
1411                struct commit *commit = handle_commit(revs, e->item, e->name);
1412                if (commit) {
1413                        if (!(commit->object.flags & SEEN)) {
1414                                commit->object.flags |= SEEN;
1415                                insert_by_date(commit, &revs->commits);
1416                        }
1417                }
1418                e++;
1419        }
1420        free(list);
1421
1422        if (revs->no_walk)
1423                return 0;
1424        if (revs->limited)
1425                if (limit_list(revs) < 0)
1426                        return -1;
1427        if (revs->topo_order)
1428                sort_in_topological_order(&revs->commits, revs->lifo);
1429        return 0;
1430}
1431
1432enum rewrite_result {
1433        rewrite_one_ok,
1434        rewrite_one_noparents,
1435        rewrite_one_error,
1436};
1437
1438static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
1439{
1440        for (;;) {
1441                struct commit *p = *pp;
1442                if (!revs->limited)
1443                        if (add_parents_to_list(revs, p, &revs->commits) < 0)
1444                                return rewrite_one_error;
1445                if (p->parents && p->parents->next)
1446                        return rewrite_one_ok;
1447                if (p->object.flags & UNINTERESTING)
1448                        return rewrite_one_ok;
1449                if (!(p->object.flags & TREESAME))
1450                        return rewrite_one_ok;
1451                if (!p->parents)
1452                        return rewrite_one_noparents;
1453                *pp = p->parents->item;
1454        }
1455}
1456
1457static void remove_duplicate_parents(struct commit *commit)
1458{
1459        struct commit_list **pp, *p;
1460
1461        /* Examine existing parents while marking ones we have seen... */
1462        pp = &commit->parents;
1463        while ((p = *pp) != NULL) {
1464                struct commit *parent = p->item;
1465                if (parent->object.flags & TMP_MARK) {
1466                        *pp = p->next;
1467                        continue;
1468                }
1469                parent->object.flags |= TMP_MARK;
1470                pp = &p->next;
1471        }
1472        /* ... and clear the temporary mark */
1473        for (p = commit->parents; p; p = p->next)
1474                p->item->object.flags &= ~TMP_MARK;
1475}
1476
1477static int rewrite_parents(struct rev_info *revs, struct commit *commit)
1478{
1479        struct commit_list **pp = &commit->parents;
1480        while (*pp) {
1481                struct commit_list *parent = *pp;
1482                switch (rewrite_one(revs, &parent->item)) {
1483                case rewrite_one_ok:
1484                        break;
1485                case rewrite_one_noparents:
1486                        *pp = parent->next;
1487                        continue;
1488                case rewrite_one_error:
1489                        return -1;
1490                }
1491                pp = &parent->next;
1492        }
1493        remove_duplicate_parents(commit);
1494        return 0;
1495}
1496
1497static int commit_match(struct commit *commit, struct rev_info *opt)
1498{
1499        if (!opt->grep_filter)
1500                return 1;
1501        return grep_buffer(opt->grep_filter,
1502                           NULL, /* we say nothing, not even filename */
1503                           commit->buffer, strlen(commit->buffer));
1504}
1505
1506enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
1507{
1508        if (commit->object.flags & SHOWN)
1509                return commit_ignore;
1510        if (revs->unpacked && has_sha1_pack(commit->object.sha1, revs->ignore_packed))
1511                return commit_ignore;
1512        if (revs->show_all)
1513                return commit_show;
1514        if (commit->object.flags & UNINTERESTING)
1515                return commit_ignore;
1516        if (revs->min_age != -1 && (commit->date > revs->min_age))
1517                return commit_ignore;
1518        if (revs->no_merges && commit->parents && commit->parents->next)
1519                return commit_ignore;
1520        if (!commit_match(commit, revs))
1521                return commit_ignore;
1522        if (revs->prune && revs->dense) {
1523                /* Commit without changes? */
1524                if (commit->object.flags & TREESAME) {
1525                        /* drop merges unless we want parenthood */
1526                        if (!revs->parents)
1527                                return commit_ignore;
1528                        /* non-merge - always ignore it */
1529                        if (!commit->parents || !commit->parents->next)
1530                                return commit_ignore;
1531                }
1532                if (revs->parents && rewrite_parents(revs, commit) < 0)
1533                        return commit_error;
1534        }
1535        return commit_show;
1536}
1537
1538static struct commit *get_revision_1(struct rev_info *revs)
1539{
1540        if (!revs->commits)
1541                return NULL;
1542
1543        do {
1544                struct commit_list *entry = revs->commits;
1545                struct commit *commit = entry->item;
1546
1547                revs->commits = entry->next;
1548                free(entry);
1549
1550                if (revs->reflog_info)
1551                        fake_reflog_parent(revs->reflog_info, commit);
1552
1553                /*
1554                 * If we haven't done the list limiting, we need to look at
1555                 * the parents here. We also need to do the date-based limiting
1556                 * that we'd otherwise have done in limit_list().
1557                 */
1558                if (!revs->limited) {
1559                        if (revs->max_age != -1 &&
1560                            (commit->date < revs->max_age))
1561                                continue;
1562                        if (add_parents_to_list(revs, commit, &revs->commits) < 0)
1563                                return NULL;
1564                }
1565
1566                switch (simplify_commit(revs, commit)) {
1567                case commit_ignore:
1568                        continue;
1569                case commit_error:
1570                        return NULL;
1571                default:
1572                        return commit;
1573                }
1574        } while (revs->commits);
1575        return NULL;
1576}
1577
1578static void gc_boundary(struct object_array *array)
1579{
1580        unsigned nr = array->nr;
1581        unsigned alloc = array->alloc;
1582        struct object_array_entry *objects = array->objects;
1583
1584        if (alloc <= nr) {
1585                unsigned i, j;
1586                for (i = j = 0; i < nr; i++) {
1587                        if (objects[i].item->flags & SHOWN)
1588                                continue;
1589                        if (i != j)
1590                                objects[j] = objects[i];
1591                        j++;
1592                }
1593                for (i = j; i < nr; i++)
1594                        objects[i].item = NULL;
1595                array->nr = j;
1596        }
1597}
1598
1599struct commit *get_revision(struct rev_info *revs)
1600{
1601        struct commit *c = NULL;
1602        struct commit_list *l;
1603
1604        if (revs->boundary == 2) {
1605                unsigned i;
1606                struct object_array *array = &revs->boundary_commits;
1607                struct object_array_entry *objects = array->objects;
1608                for (i = 0; i < array->nr; i++) {
1609                        c = (struct commit *)(objects[i].item);
1610                        if (!c)
1611                                continue;
1612                        if (!(c->object.flags & CHILD_SHOWN))
1613                                continue;
1614                        if (!(c->object.flags & SHOWN))
1615                                break;
1616                }
1617                if (array->nr <= i)
1618                        return NULL;
1619
1620                c->object.flags |= SHOWN | BOUNDARY;
1621                return c;
1622        }
1623
1624        if (revs->reverse) {
1625                int limit = -1;
1626
1627                if (0 <= revs->max_count) {
1628                        limit = revs->max_count;
1629                        if (0 < revs->skip_count)
1630                                limit += revs->skip_count;
1631                }
1632                l = NULL;
1633                while ((c = get_revision_1(revs))) {
1634                        commit_list_insert(c, &l);
1635                        if ((0 < limit) && !--limit)
1636                                break;
1637                }
1638                revs->commits = l;
1639                revs->reverse = 0;
1640                revs->max_count = -1;
1641                c = NULL;
1642        }
1643
1644        /*
1645         * Now pick up what they want to give us
1646         */
1647        c = get_revision_1(revs);
1648        if (c) {
1649                while (0 < revs->skip_count) {
1650                        revs->skip_count--;
1651                        c = get_revision_1(revs);
1652                        if (!c)
1653                                break;
1654                }
1655        }
1656
1657        /*
1658         * Check the max_count.
1659         */
1660        switch (revs->max_count) {
1661        case -1:
1662                break;
1663        case 0:
1664                c = NULL;
1665                break;
1666        default:
1667                revs->max_count--;
1668        }
1669
1670        if (c)
1671                c->object.flags |= SHOWN;
1672
1673        if (!revs->boundary) {
1674                return c;
1675        }
1676
1677        if (!c) {
1678                /*
1679                 * get_revision_1() runs out the commits, and
1680                 * we are done computing the boundaries.
1681                 * switch to boundary commits output mode.
1682                 */
1683                revs->boundary = 2;
1684                return get_revision(revs);
1685        }
1686
1687        /*
1688         * boundary commits are the commits that are parents of the
1689         * ones we got from get_revision_1() but they themselves are
1690         * not returned from get_revision_1().  Before returning
1691         * 'c', we need to mark its parents that they could be boundaries.
1692         */
1693
1694        for (l = c->parents; l; l = l->next) {
1695                struct object *p;
1696                p = &(l->item->object);
1697                if (p->flags & (CHILD_SHOWN | SHOWN))
1698                        continue;
1699                p->flags |= CHILD_SHOWN;
1700                gc_boundary(&revs->boundary_commits);
1701                add_object_array(p, NULL, &revs->boundary_commits);
1702        }
1703
1704        return c;
1705}