Andrew's git / gitweb.git / revision.c
?
revision.con commit Merge branch 'ew/maint-svn-cert-fileprovider' (7385a42)
   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
 567static void add_to_list(struct commit_list **p, struct commit *commit, struct commit_list *n)
 568{
 569        p = &commit_list_insert(commit, p)->next;
 570        *p = n;
 571}
 572
 573static int limit_list(struct rev_info *revs)
 574{
 575        struct commit_list *list = revs->commits;
 576        struct commit_list *newlist = NULL;
 577        struct commit_list **p = &newlist;
 578
 579        while (list) {
 580                struct commit_list *entry = list;
 581                struct commit *commit = list->item;
 582                struct object *obj = &commit->object;
 583                show_early_output_fn_t show;
 584
 585                list = list->next;
 586                free(entry);
 587
 588                if (revs->max_age != -1 && (commit->date < revs->max_age))
 589                        obj->flags |= UNINTERESTING;
 590                if (add_parents_to_list(revs, commit, &list) < 0)
 591                        return -1;
 592                if (obj->flags & UNINTERESTING) {
 593                        mark_parents_uninteresting(commit);
 594                        if (everybody_uninteresting(list)) {
 595                                if (revs->show_all)
 596                                        add_to_list(p, commit, list);
 597                                break;
 598                        }
 599                        if (!revs->show_all)
 600                                continue;
 601                }
 602                if (revs->min_age != -1 && (commit->date > revs->min_age))
 603                        continue;
 604                p = &commit_list_insert(commit, p)->next;
 605
 606                show = show_early_output;
 607                if (!show)
 608                        continue;
 609
 610                show(revs, newlist);
 611                show_early_output = NULL;
 612        }
 613        if (revs->cherry_pick)
 614                cherry_pick_list(newlist, revs);
 615
 616        revs->commits = newlist;
 617        return 0;
 618}
 619
 620struct all_refs_cb {
 621        int all_flags;
 622        int warned_bad_reflog;
 623        struct rev_info *all_revs;
 624        const char *name_for_errormsg;
 625};
 626
 627static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 628{
 629        struct all_refs_cb *cb = cb_data;
 630        struct object *object = get_reference(cb->all_revs, path, sha1,
 631                                              cb->all_flags);
 632        add_pending_object(cb->all_revs, object, path);
 633        return 0;
 634}
 635
 636static void handle_refs(struct rev_info *revs, unsigned flags,
 637                int (*for_each)(each_ref_fn, void *))
 638{
 639        struct all_refs_cb cb;
 640        cb.all_revs = revs;
 641        cb.all_flags = flags;
 642        for_each(handle_one_ref, &cb);
 643}
 644
 645static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
 646{
 647        struct all_refs_cb *cb = cb_data;
 648        if (!is_null_sha1(sha1)) {
 649                struct object *o = parse_object(sha1);
 650                if (o) {
 651                        o->flags |= cb->all_flags;
 652                        add_pending_object(cb->all_revs, o, "");
 653                }
 654                else if (!cb->warned_bad_reflog) {
 655                        warning("reflog of '%s' references pruned commits",
 656                                cb->name_for_errormsg);
 657                        cb->warned_bad_reflog = 1;
 658                }
 659        }
 660}
 661
 662static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 663                const char *email, unsigned long timestamp, int tz,
 664                const char *message, void *cb_data)
 665{
 666        handle_one_reflog_commit(osha1, cb_data);
 667        handle_one_reflog_commit(nsha1, cb_data);
 668        return 0;
 669}
 670
 671static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 672{
 673        struct all_refs_cb *cb = cb_data;
 674        cb->warned_bad_reflog = 0;
 675        cb->name_for_errormsg = path;
 676        for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
 677        return 0;
 678}
 679
 680static void handle_reflog(struct rev_info *revs, unsigned flags)
 681{
 682        struct all_refs_cb cb;
 683        cb.all_revs = revs;
 684        cb.all_flags = flags;
 685        for_each_reflog(handle_one_reflog, &cb);
 686}
 687
 688static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
 689{
 690        unsigned char sha1[20];
 691        struct object *it;
 692        struct commit *commit;
 693        struct commit_list *parents;
 694
 695        if (*arg == '^') {
 696                flags ^= UNINTERESTING;
 697                arg++;
 698        }
 699        if (get_sha1(arg, sha1))
 700                return 0;
 701        while (1) {
 702                it = get_reference(revs, arg, sha1, 0);
 703                if (it->type != OBJ_TAG)
 704                        break;
 705                if (!((struct tag*)it)->tagged)
 706                        return 0;
 707                hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
 708        }
 709        if (it->type != OBJ_COMMIT)
 710                return 0;
 711        commit = (struct commit *)it;
 712        for (parents = commit->parents; parents; parents = parents->next) {
 713                it = &parents->item->object;
 714                it->flags |= flags;
 715                add_pending_object(revs, it, arg);
 716        }
 717        return 1;
 718}
 719
 720void init_revisions(struct rev_info *revs, const char *prefix)
 721{
 722        memset(revs, 0, sizeof(*revs));
 723
 724        revs->abbrev = DEFAULT_ABBREV;
 725        revs->ignore_merges = 1;
 726        revs->simplify_history = 1;
 727        DIFF_OPT_SET(&revs->pruning, RECURSIVE);
 728        DIFF_OPT_SET(&revs->pruning, QUIET);
 729        revs->pruning.add_remove = file_add_remove;
 730        revs->pruning.change = file_change;
 731        revs->lifo = 1;
 732        revs->dense = 1;
 733        revs->prefix = prefix;
 734        revs->max_age = -1;
 735        revs->min_age = -1;
 736        revs->skip_count = -1;
 737        revs->max_count = -1;
 738
 739        revs->commit_format = CMIT_FMT_DEFAULT;
 740
 741        diff_setup(&revs->diffopt);
 742        if (prefix && !revs->diffopt.prefix) {
 743                revs->diffopt.prefix = prefix;
 744                revs->diffopt.prefix_length = strlen(prefix);
 745        }
 746}
 747
 748static void add_pending_commit_list(struct rev_info *revs,
 749                                    struct commit_list *commit_list,
 750                                    unsigned int flags)
 751{
 752        while (commit_list) {
 753                struct object *object = &commit_list->item->object;
 754                object->flags |= flags;
 755                add_pending_object(revs, object, sha1_to_hex(object->sha1));
 756                commit_list = commit_list->next;
 757        }
 758}
 759
 760static void prepare_show_merge(struct rev_info *revs)
 761{
 762        struct commit_list *bases;
 763        struct commit *head, *other;
 764        unsigned char sha1[20];
 765        const char **prune = NULL;
 766        int i, prune_num = 1; /* counting terminating NULL */
 767
 768        if (get_sha1("HEAD", sha1) || !(head = lookup_commit(sha1)))
 769                die("--merge without HEAD?");
 770        if (get_sha1("MERGE_HEAD", sha1) || !(other = lookup_commit(sha1)))
 771                die("--merge without MERGE_HEAD?");
 772        add_pending_object(revs, &head->object, "HEAD");
 773        add_pending_object(revs, &other->object, "MERGE_HEAD");
 774        bases = get_merge_bases(head, other, 1);
 775        while (bases) {
 776                struct commit *it = bases->item;
 777                struct commit_list *n = bases->next;
 778                free(bases);
 779                bases = n;
 780                it->object.flags |= UNINTERESTING;
 781                add_pending_object(revs, &it->object, "(merge-base)");
 782        }
 783
 784        if (!active_nr)
 785                read_cache();
 786        for (i = 0; i < active_nr; i++) {
 787                struct cache_entry *ce = active_cache[i];
 788                if (!ce_stage(ce))
 789                        continue;
 790                if (ce_path_match(ce, revs->prune_data)) {
 791                        prune_num++;
 792                        prune = xrealloc(prune, sizeof(*prune) * prune_num);
 793                        prune[prune_num-2] = ce->name;
 794                        prune[prune_num-1] = NULL;
 795                }
 796                while ((i+1 < active_nr) &&
 797                       ce_same_name(ce, active_cache[i+1]))
 798                        i++;
 799        }
 800        revs->prune_data = prune;
 801}
 802
 803int handle_revision_arg(const char *arg, struct rev_info *revs,
 804                        int flags,
 805                        int cant_be_filename)
 806{
 807        unsigned mode;
 808        char *dotdot;
 809        struct object *object;
 810        unsigned char sha1[20];
 811        int local_flags;
 812
 813        dotdot = strstr(arg, "..");
 814        if (dotdot) {
 815                unsigned char from_sha1[20];
 816                const char *next = dotdot + 2;
 817                const char *this = arg;
 818                int symmetric = *next == '.';
 819                unsigned int flags_exclude = flags ^ UNINTERESTING;
 820
 821                *dotdot = 0;
 822                next += symmetric;
 823
 824                if (!*next)
 825                        next = "HEAD";
 826                if (dotdot == arg)
 827                        this = "HEAD";
 828                if (!get_sha1(this, from_sha1) &&
 829                    !get_sha1(next, sha1)) {
 830                        struct commit *a, *b;
 831                        struct commit_list *exclude;
 832
 833                        a = lookup_commit_reference(from_sha1);
 834                        b = lookup_commit_reference(sha1);
 835                        if (!a || !b) {
 836                                die(symmetric ?
 837                                    "Invalid symmetric difference expression %s...%s" :
 838                                    "Invalid revision range %s..%s",
 839                                    arg, next);
 840                        }
 841
 842                        if (!cant_be_filename) {
 843                                *dotdot = '.';
 844                                verify_non_filename(revs->prefix, arg);
 845                        }
 846
 847                        if (symmetric) {
 848                                exclude = get_merge_bases(a, b, 1);
 849                                add_pending_commit_list(revs, exclude,
 850                                                        flags_exclude);
 851                                free_commit_list(exclude);
 852                                a->object.flags |= flags | SYMMETRIC_LEFT;
 853                        } else
 854                                a->object.flags |= flags_exclude;
 855                        b->object.flags |= flags;
 856                        add_pending_object(revs, &a->object, this);
 857                        add_pending_object(revs, &b->object, next);
 858                        return 0;
 859                }
 860                *dotdot = '.';
 861        }
 862        dotdot = strstr(arg, "^@");
 863        if (dotdot && !dotdot[2]) {
 864                *dotdot = 0;
 865                if (add_parents_only(revs, arg, flags))
 866                        return 0;
 867                *dotdot = '^';
 868        }
 869        dotdot = strstr(arg, "^!");
 870        if (dotdot && !dotdot[2]) {
 871                *dotdot = 0;
 872                if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
 873                        *dotdot = '^';
 874        }
 875
 876        local_flags = 0;
 877        if (*arg == '^') {
 878                local_flags = UNINTERESTING;
 879                arg++;
 880        }
 881        if (get_sha1_with_mode(arg, sha1, &mode))
 882                return -1;
 883        if (!cant_be_filename)
 884                verify_non_filename(revs->prefix, arg);
 885        object = get_reference(revs, arg, sha1, flags ^ local_flags);
 886        add_pending_object_with_mode(revs, object, arg, mode);
 887        return 0;
 888}
 889
 890static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
 891{
 892        if (!revs->grep_filter) {
 893                struct grep_opt *opt = xcalloc(1, sizeof(*opt));
 894                opt->status_only = 1;
 895                opt->pattern_tail = &(opt->pattern_list);
 896                opt->regflags = REG_NEWLINE;
 897                revs->grep_filter = opt;
 898        }
 899        append_grep_pattern(revs->grep_filter, ptn,
 900                            "command line", 0, what);
 901}
 902
 903static void add_header_grep(struct rev_info *revs, const char *field, const char *pattern)
 904{
 905        char *pat;
 906        const char *prefix;
 907        int patlen, fldlen;
 908
 909        fldlen = strlen(field);
 910        patlen = strlen(pattern);
 911        pat = xmalloc(patlen + fldlen + 10);
 912        prefix = ".*";
 913        if (*pattern == '^') {
 914                prefix = "";
 915                pattern++;
 916        }
 917        sprintf(pat, "^%s %s%s", field, prefix, pattern);
 918        add_grep(revs, pat, GREP_PATTERN_HEAD);
 919}
 920
 921static void add_message_grep(struct rev_info *revs, const char *pattern)
 922{
 923        add_grep(revs, pattern, GREP_PATTERN_BODY);
 924}
 925
 926static void add_ignore_packed(struct rev_info *revs, const char *name)
 927{
 928        int num = ++revs->num_ignore_packed;
 929
 930        revs->ignore_packed = xrealloc(revs->ignore_packed,
 931                                       sizeof(const char **) * (num + 1));
 932        revs->ignore_packed[num-1] = name;
 933        revs->ignore_packed[num] = NULL;
 934}
 935
 936/*
 937 * Parse revision information, filling in the "rev_info" structure,
 938 * and removing the used arguments from the argument list.
 939 *
 940 * Returns the number of arguments left that weren't recognized
 941 * (which are also moved to the head of the argument list)
 942 */
 943int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
 944{
 945        int i, flags, seen_dashdash, show_merge;
 946        const char **unrecognized = argv + 1;
 947        int left = 1;
 948        int all_match = 0;
 949        int regflags = 0;
 950        int fixed = 0;
 951
 952        /* First, search for "--" */
 953        seen_dashdash = 0;
 954        for (i = 1; i < argc; i++) {
 955                const char *arg = argv[i];
 956                if (strcmp(arg, "--"))
 957                        continue;
 958                argv[i] = NULL;
 959                argc = i;
 960                if (argv[i + 1])
 961                        revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
 962                seen_dashdash = 1;
 963                break;
 964        }
 965
 966        flags = show_merge = 0;
 967        for (i = 1; i < argc; i++) {
 968                const char *arg = argv[i];
 969                if (*arg == '-') {
 970                        int opts;
 971                        if (!prefixcmp(arg, "--max-count=")) {
 972                                revs->max_count = atoi(arg + 12);
 973                                continue;
 974                        }
 975                        if (!prefixcmp(arg, "--skip=")) {
 976                                revs->skip_count = atoi(arg + 7);
 977                                continue;
 978                        }
 979                        /* accept -<digit>, like traditional "head" */
 980                        if ((*arg == '-') && isdigit(arg[1])) {
 981                                revs->max_count = atoi(arg + 1);
 982                                continue;
 983                        }
 984                        if (!strcmp(arg, "-n")) {
 985                                if (argc <= i + 1)
 986                                        die("-n requires an argument");
 987                                revs->max_count = atoi(argv[++i]);
 988                                continue;
 989                        }
 990                        if (!prefixcmp(arg, "-n")) {
 991                                revs->max_count = atoi(arg + 2);
 992                                continue;
 993                        }
 994                        if (!prefixcmp(arg, "--max-age=")) {
 995                                revs->max_age = atoi(arg + 10);
 996                                continue;
 997                        }
 998                        if (!prefixcmp(arg, "--since=")) {
 999                                revs->max_age = approxidate(arg + 8);
1000                                continue;
1001                        }
1002                        if (!prefixcmp(arg, "--after=")) {
1003                                revs->max_age = approxidate(arg + 8);
1004                                continue;
1005                        }
1006                        if (!prefixcmp(arg, "--min-age=")) {
1007                                revs->min_age = atoi(arg + 10);
1008                                continue;
1009                        }
1010                        if (!prefixcmp(arg, "--before=")) {
1011                                revs->min_age = approxidate(arg + 9);
1012                                continue;
1013                        }
1014                        if (!prefixcmp(arg, "--until=")) {
1015                                revs->min_age = approxidate(arg + 8);
1016                                continue;
1017                        }
1018                        if (!strcmp(arg, "--all")) {
1019                                handle_refs(revs, flags, for_each_ref);
1020                                continue;
1021                        }
1022                        if (!strcmp(arg, "--branches")) {
1023                                handle_refs(revs, flags, for_each_branch_ref);
1024                                continue;
1025                        }
1026                        if (!strcmp(arg, "--tags")) {
1027                                handle_refs(revs, flags, for_each_tag_ref);
1028                                continue;
1029                        }
1030                        if (!strcmp(arg, "--remotes")) {
1031                                handle_refs(revs, flags, for_each_remote_ref);
1032                                continue;
1033                        }
1034                        if (!strcmp(arg, "--first-parent")) {
1035                                revs->first_parent_only = 1;
1036                                continue;
1037                        }
1038                        if (!strcmp(arg, "--reflog")) {
1039                                handle_reflog(revs, flags);
1040                                continue;
1041                        }
1042                        if (!strcmp(arg, "-g") ||
1043                                        !strcmp(arg, "--walk-reflogs")) {
1044                                init_reflog_walk(&revs->reflog_info);
1045                                continue;
1046                        }
1047                        if (!strcmp(arg, "--not")) {
1048                                flags ^= UNINTERESTING;
1049                                continue;
1050                        }
1051                        if (!strcmp(arg, "--default")) {
1052                                if (++i >= argc)
1053                                        die("bad --default argument");
1054                                def = argv[i];
1055                                continue;
1056                        }
1057                        if (!strcmp(arg, "--merge")) {
1058                                show_merge = 1;
1059                                continue;
1060                        }
1061                        if (!strcmp(arg, "--topo-order")) {
1062                                revs->topo_order = 1;
1063                                continue;
1064                        }
1065                        if (!strcmp(arg, "--date-order")) {
1066                                revs->lifo = 0;
1067                                revs->topo_order = 1;
1068                                continue;
1069                        }
1070                        if (!prefixcmp(arg, "--early-output")) {
1071                                int count = 100;
1072                                switch (arg[14]) {
1073                                case '=':
1074                                        count = atoi(arg+15);
1075                                        /* Fallthrough */
1076                                case 0:
1077                                        revs->topo_order = 1;
1078                                        revs->early_output = count;
1079                                        continue;
1080                                }
1081                        }
1082                        if (!strcmp(arg, "--parents")) {
1083                                revs->parents = 1;
1084                                continue;
1085                        }
1086                        if (!strcmp(arg, "--dense")) {
1087                                revs->dense = 1;
1088                                continue;
1089                        }
1090                        if (!strcmp(arg, "--sparse")) {
1091                                revs->dense = 0;
1092                                continue;
1093                        }
1094                        if (!strcmp(arg, "--show-all")) {
1095                                revs->show_all = 1;
1096                                continue;
1097                        }
1098                        if (!strcmp(arg, "--remove-empty")) {
1099                                revs->remove_empty_trees = 1;
1100                                continue;
1101                        }
1102                        if (!strcmp(arg, "--no-merges")) {
1103                                revs->no_merges = 1;
1104                                continue;
1105                        }
1106                        if (!strcmp(arg, "--boundary")) {
1107                                revs->boundary = 1;
1108                                continue;
1109                        }
1110                        if (!strcmp(arg, "--left-right")) {
1111                                revs->left_right = 1;
1112                                continue;
1113                        }
1114                        if (!strcmp(arg, "--cherry-pick")) {
1115                                revs->cherry_pick = 1;
1116                                revs->limited = 1;
1117                                continue;
1118                        }
1119                        if (!strcmp(arg, "--objects")) {
1120                                revs->tag_objects = 1;
1121                                revs->tree_objects = 1;
1122                                revs->blob_objects = 1;
1123                                continue;
1124                        }
1125                        if (!strcmp(arg, "--objects-edge")) {
1126                                revs->tag_objects = 1;
1127                                revs->tree_objects = 1;
1128                                revs->blob_objects = 1;
1129                                revs->edge_hint = 1;
1130                                continue;
1131                        }
1132                        if (!strcmp(arg, "--unpacked")) {
1133                                revs->unpacked = 1;
1134                                free(revs->ignore_packed);
1135                                revs->ignore_packed = NULL;
1136                                revs->num_ignore_packed = 0;
1137                                continue;
1138                        }
1139                        if (!prefixcmp(arg, "--unpacked=")) {
1140                                revs->unpacked = 1;
1141                                add_ignore_packed(revs, arg+11);
1142                                continue;
1143                        }
1144                        if (!strcmp(arg, "-r")) {
1145                                revs->diff = 1;
1146                                DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1147                                continue;
1148                        }
1149                        if (!strcmp(arg, "-t")) {
1150                                revs->diff = 1;
1151                                DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1152                                DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1153                                continue;
1154                        }
1155                        if (!strcmp(arg, "-m")) {
1156                                revs->ignore_merges = 0;
1157                                continue;
1158                        }
1159                        if (!strcmp(arg, "-c")) {
1160                                revs->diff = 1;
1161                                revs->dense_combined_merges = 0;
1162                                revs->combine_merges = 1;
1163                                continue;
1164                        }
1165                        if (!strcmp(arg, "--cc")) {
1166                                revs->diff = 1;
1167                                revs->dense_combined_merges = 1;
1168                                revs->combine_merges = 1;
1169                                continue;
1170                        }
1171                        if (!strcmp(arg, "-v")) {
1172                                revs->verbose_header = 1;
1173                                continue;
1174                        }
1175                        if (!prefixcmp(arg, "--pretty")) {
1176                                revs->verbose_header = 1;
1177                                revs->commit_format = get_commit_format(arg+8);
1178                                continue;
1179                        }
1180                        if (!strcmp(arg, "--root")) {
1181                                revs->show_root_diff = 1;
1182                                continue;
1183                        }
1184                        if (!strcmp(arg, "--no-commit-id")) {
1185                                revs->no_commit_id = 1;
1186                                continue;
1187                        }
1188                        if (!strcmp(arg, "--always")) {
1189                                revs->always_show_header = 1;
1190                                continue;
1191                        }
1192                        if (!strcmp(arg, "--no-abbrev")) {
1193                                revs->abbrev = 0;
1194                                continue;
1195                        }
1196                        if (!strcmp(arg, "--abbrev")) {
1197                                revs->abbrev = DEFAULT_ABBREV;
1198                                continue;
1199                        }
1200                        if (!prefixcmp(arg, "--abbrev=")) {
1201                                revs->abbrev = strtoul(arg + 9, NULL, 10);
1202                                if (revs->abbrev < MINIMUM_ABBREV)
1203                                        revs->abbrev = MINIMUM_ABBREV;
1204                                else if (revs->abbrev > 40)
1205                                        revs->abbrev = 40;
1206                                continue;
1207                        }
1208                        if (!strcmp(arg, "--abbrev-commit")) {
1209                                revs->abbrev_commit = 1;
1210                                continue;
1211                        }
1212                        if (!strcmp(arg, "--full-diff")) {
1213                                revs->diff = 1;
1214                                revs->full_diff = 1;
1215                                continue;
1216                        }
1217                        if (!strcmp(arg, "--full-history")) {
1218                                revs->simplify_history = 0;
1219                                continue;
1220                        }
1221                        if (!strcmp(arg, "--relative-date")) {
1222                                revs->date_mode = DATE_RELATIVE;
1223                                continue;
1224                        }
1225                        if (!strncmp(arg, "--date=", 7)) {
1226                                revs->date_mode = parse_date_format(arg + 7);
1227                                continue;
1228                        }
1229                        if (!strcmp(arg, "--log-size")) {
1230                                revs->show_log_size = 1;
1231                                continue;
1232                        }
1233
1234                        /*
1235                         * Grepping the commit log
1236                         */
1237                        if (!prefixcmp(arg, "--author=")) {
1238                                add_header_grep(revs, "author", arg+9);
1239                                continue;
1240                        }
1241                        if (!prefixcmp(arg, "--committer=")) {
1242                                add_header_grep(revs, "committer", arg+12);
1243                                continue;
1244                        }
1245                        if (!prefixcmp(arg, "--grep=")) {
1246                                add_message_grep(revs, arg+7);
1247                                continue;
1248                        }
1249                        if (!strcmp(arg, "--extended-regexp") ||
1250                            !strcmp(arg, "-E")) {
1251                                regflags |= REG_EXTENDED;
1252                                continue;
1253                        }
1254                        if (!strcmp(arg, "--regexp-ignore-case") ||
1255                            !strcmp(arg, "-i")) {
1256                                regflags |= REG_ICASE;
1257                                continue;
1258                        }
1259                        if (!strcmp(arg, "--fixed-strings") ||
1260                            !strcmp(arg, "-F")) {
1261                                fixed = 1;
1262                                continue;
1263                        }
1264                        if (!strcmp(arg, "--all-match")) {
1265                                all_match = 1;
1266                                continue;
1267                        }
1268                        if (!prefixcmp(arg, "--encoding=")) {
1269                                arg += 11;
1270                                if (strcmp(arg, "none"))
1271                                        git_log_output_encoding = xstrdup(arg);
1272                                else
1273                                        git_log_output_encoding = "";
1274                                continue;
1275                        }
1276                        if (!strcmp(arg, "--reverse")) {
1277                                revs->reverse ^= 1;
1278                                continue;
1279                        }
1280                        if (!strcmp(arg, "--no-walk")) {
1281                                revs->no_walk = 1;
1282                                continue;
1283                        }
1284                        if (!strcmp(arg, "--do-walk")) {
1285                                revs->no_walk = 0;
1286                                continue;
1287                        }
1288
1289                        opts = diff_opt_parse(&revs->diffopt, argv+i, argc-i);
1290                        if (opts > 0) {
1291                                i += opts - 1;
1292                                continue;
1293                        }
1294                        *unrecognized++ = arg;
1295                        left++;
1296                        continue;
1297                }
1298
1299                if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
1300                        int j;
1301                        if (seen_dashdash || *arg == '^')
1302                                die("bad revision '%s'", arg);
1303
1304                        /* If we didn't have a "--":
1305                         * (1) all filenames must exist;
1306                         * (2) all rev-args must not be interpretable
1307                         *     as a valid filename.
1308                         * but the latter we have checked in the main loop.
1309                         */
1310                        for (j = i; j < argc; j++)
1311                                verify_filename(revs->prefix, argv[j]);
1312
1313                        revs->prune_data = get_pathspec(revs->prefix,
1314                                                        argv + i);
1315                        break;
1316                }
1317        }
1318
1319        if (revs->grep_filter) {
1320                revs->grep_filter->regflags |= regflags;
1321                revs->grep_filter->fixed = fixed;
1322        }
1323
1324        if (show_merge)
1325                prepare_show_merge(revs);
1326        if (def && !revs->pending.nr) {
1327                unsigned char sha1[20];
1328                struct object *object;
1329                unsigned mode;
1330                if (get_sha1_with_mode(def, sha1, &mode))
1331                        die("bad default revision '%s'", def);
1332                object = get_reference(revs, def, sha1, 0);
1333                add_pending_object_with_mode(revs, object, def, mode);
1334        }
1335
1336        /* Did the user ask for any diff output? Run the diff! */
1337        if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
1338                revs->diff = 1;
1339
1340        /* Pickaxe, diff-filter and rename following need diffs */
1341        if (revs->diffopt.pickaxe ||
1342            revs->diffopt.filter ||
1343            DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1344                revs->diff = 1;
1345
1346        if (revs->topo_order)
1347                revs->limited = 1;
1348
1349        if (revs->prune_data) {
1350                diff_tree_setup_paths(revs->prune_data, &revs->pruning);
1351                /* Can't prune commits with rename following: the paths change.. */
1352                if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1353                        revs->prune = 1;
1354                if (!revs->full_diff)
1355                        diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
1356        }
1357        if (revs->combine_merges) {
1358                revs->ignore_merges = 0;
1359                if (revs->dense_combined_merges && !revs->diffopt.output_format)
1360                        revs->diffopt.output_format = DIFF_FORMAT_PATCH;
1361        }
1362        revs->diffopt.abbrev = revs->abbrev;
1363        if (diff_setup_done(&revs->diffopt) < 0)
1364                die("diff_setup_done failed");
1365
1366        if (revs->grep_filter) {
1367                revs->grep_filter->all_match = all_match;
1368                compile_grep_patterns(revs->grep_filter);
1369        }
1370
1371        if (revs->reverse && revs->reflog_info)
1372                die("cannot combine --reverse with --walk-reflogs");
1373
1374        return left;
1375}
1376
1377int prepare_revision_walk(struct rev_info *revs)
1378{
1379        int nr = revs->pending.nr;
1380        struct object_array_entry *e, *list;
1381
1382        e = list = revs->pending.objects;
1383        revs->pending.nr = 0;
1384        revs->pending.alloc = 0;
1385        revs->pending.objects = NULL;
1386        while (--nr >= 0) {
1387                struct commit *commit = handle_commit(revs, e->item, e->name);
1388                if (commit) {
1389                        if (!(commit->object.flags & SEEN)) {
1390                                commit->object.flags |= SEEN;
1391                                insert_by_date(commit, &revs->commits);
1392                        }
1393                }
1394                e++;
1395        }
1396        free(list);
1397
1398        if (revs->no_walk)
1399                return 0;
1400        if (revs->limited)
1401                if (limit_list(revs) < 0)
1402                        return -1;
1403        if (revs->topo_order)
1404                sort_in_topological_order(&revs->commits, revs->lifo);
1405        return 0;
1406}
1407
1408enum rewrite_result {
1409        rewrite_one_ok,
1410        rewrite_one_noparents,
1411        rewrite_one_error,
1412};
1413
1414static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
1415{
1416        for (;;) {
1417                struct commit *p = *pp;
1418                if (!revs->limited)
1419                        if (add_parents_to_list(revs, p, &revs->commits) < 0)
1420                                return rewrite_one_error;
1421                if (p->parents && p->parents->next)
1422                        return rewrite_one_ok;
1423                if (p->object.flags & UNINTERESTING)
1424                        return rewrite_one_ok;
1425                if (!(p->object.flags & TREESAME))
1426                        return rewrite_one_ok;
1427                if (!p->parents)
1428                        return rewrite_one_noparents;
1429                *pp = p->parents->item;
1430        }
1431}
1432
1433static void remove_duplicate_parents(struct commit *commit)
1434{
1435        struct commit_list **pp, *p;
1436
1437        /* Examine existing parents while marking ones we have seen... */
1438        pp = &commit->parents;
1439        while ((p = *pp) != NULL) {
1440                struct commit *parent = p->item;
1441                if (parent->object.flags & TMP_MARK) {
1442                        *pp = p->next;
1443                        continue;
1444                }
1445                parent->object.flags |= TMP_MARK;
1446                pp = &p->next;
1447        }
1448        /* ... and clear the temporary mark */
1449        for (p = commit->parents; p; p = p->next)
1450                p->item->object.flags &= ~TMP_MARK;
1451}
1452
1453static int rewrite_parents(struct rev_info *revs, struct commit *commit)
1454{
1455        struct commit_list **pp = &commit->parents;
1456        while (*pp) {
1457                struct commit_list *parent = *pp;
1458                switch (rewrite_one(revs, &parent->item)) {
1459                case rewrite_one_ok:
1460                        break;
1461                case rewrite_one_noparents:
1462                        *pp = parent->next;
1463                        continue;
1464                case rewrite_one_error:
1465                        return -1;
1466                }
1467                pp = &parent->next;
1468        }
1469        remove_duplicate_parents(commit);
1470        return 0;
1471}
1472
1473static int commit_match(struct commit *commit, struct rev_info *opt)
1474{
1475        if (!opt->grep_filter)
1476                return 1;
1477        return grep_buffer(opt->grep_filter,
1478                           NULL, /* we say nothing, not even filename */
1479                           commit->buffer, strlen(commit->buffer));
1480}
1481
1482enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
1483{
1484        if (commit->object.flags & SHOWN)
1485                return commit_ignore;
1486        if (revs->unpacked && has_sha1_pack(commit->object.sha1, revs->ignore_packed))
1487                return commit_ignore;
1488        if (revs->show_all)
1489                return commit_show;
1490        if (commit->object.flags & UNINTERESTING)
1491                return commit_ignore;
1492        if (revs->min_age != -1 && (commit->date > revs->min_age))
1493                return commit_ignore;
1494        if (revs->no_merges && commit->parents && commit->parents->next)
1495                return commit_ignore;
1496        if (!commit_match(commit, revs))
1497                return commit_ignore;
1498        if (revs->prune && revs->dense) {
1499                /* Commit without changes? */
1500                if (commit->object.flags & TREESAME) {
1501                        /* drop merges unless we want parenthood */
1502                        if (!revs->parents)
1503                                return commit_ignore;
1504                        /* non-merge - always ignore it */
1505                        if (!commit->parents || !commit->parents->next)
1506                                return commit_ignore;
1507                }
1508                if (revs->parents && rewrite_parents(revs, commit) < 0)
1509                        return commit_error;
1510        }
1511        return commit_show;
1512}
1513
1514static struct commit *get_revision_1(struct rev_info *revs)
1515{
1516        if (!revs->commits)
1517                return NULL;
1518
1519        do {
1520                struct commit_list *entry = revs->commits;
1521                struct commit *commit = entry->item;
1522
1523                revs->commits = entry->next;
1524                free(entry);
1525
1526                if (revs->reflog_info)
1527                        fake_reflog_parent(revs->reflog_info, commit);
1528
1529                /*
1530                 * If we haven't done the list limiting, we need to look at
1531                 * the parents here. We also need to do the date-based limiting
1532                 * that we'd otherwise have done in limit_list().
1533                 */
1534                if (!revs->limited) {
1535                        if (revs->max_age != -1 &&
1536                            (commit->date < revs->max_age))
1537                                continue;
1538                        if (add_parents_to_list(revs, commit, &revs->commits) < 0)
1539                                return NULL;
1540                }
1541
1542                switch (simplify_commit(revs, commit)) {
1543                case commit_ignore:
1544                        continue;
1545                case commit_error:
1546                        return NULL;
1547                default:
1548                        return commit;
1549                }
1550        } while (revs->commits);
1551        return NULL;
1552}
1553
1554static void gc_boundary(struct object_array *array)
1555{
1556        unsigned nr = array->nr;
1557        unsigned alloc = array->alloc;
1558        struct object_array_entry *objects = array->objects;
1559
1560        if (alloc <= nr) {
1561                unsigned i, j;
1562                for (i = j = 0; i < nr; i++) {
1563                        if (objects[i].item->flags & SHOWN)
1564                                continue;
1565                        if (i != j)
1566                                objects[j] = objects[i];
1567                        j++;
1568                }
1569                for (i = j; i < nr; i++)
1570                        objects[i].item = NULL;
1571                array->nr = j;
1572        }
1573}
1574
1575struct commit *get_revision(struct rev_info *revs)
1576{
1577        struct commit *c = NULL;
1578        struct commit_list *l;
1579
1580        if (revs->boundary == 2) {
1581                unsigned i;
1582                struct object_array *array = &revs->boundary_commits;
1583                struct object_array_entry *objects = array->objects;
1584                for (i = 0; i < array->nr; i++) {
1585                        c = (struct commit *)(objects[i].item);
1586                        if (!c)
1587                                continue;
1588                        if (!(c->object.flags & CHILD_SHOWN))
1589                                continue;
1590                        if (!(c->object.flags & SHOWN))
1591                                break;
1592                }
1593                if (array->nr <= i)
1594                        return NULL;
1595
1596                c->object.flags |= SHOWN | BOUNDARY;
1597                return c;
1598        }
1599
1600        if (revs->reverse) {
1601                int limit = -1;
1602
1603                if (0 <= revs->max_count) {
1604                        limit = revs->max_count;
1605                        if (0 < revs->skip_count)
1606                                limit += revs->skip_count;
1607                }
1608                l = NULL;
1609                while ((c = get_revision_1(revs))) {
1610                        commit_list_insert(c, &l);
1611                        if ((0 < limit) && !--limit)
1612                                break;
1613                }
1614                revs->commits = l;
1615                revs->reverse = 0;
1616                revs->max_count = -1;
1617                c = NULL;
1618        }
1619
1620        /*
1621         * Now pick up what they want to give us
1622         */
1623        c = get_revision_1(revs);
1624        if (c) {
1625                while (0 < revs->skip_count) {
1626                        revs->skip_count--;
1627                        c = get_revision_1(revs);
1628                        if (!c)
1629                                break;
1630                }
1631        }
1632
1633        /*
1634         * Check the max_count.
1635         */
1636        switch (revs->max_count) {
1637        case -1:
1638                break;
1639        case 0:
1640                c = NULL;
1641                break;
1642        default:
1643                revs->max_count--;
1644        }
1645
1646        if (c)
1647                c->object.flags |= SHOWN;
1648
1649        if (!revs->boundary) {
1650                return c;
1651        }
1652
1653        if (!c) {
1654                /*
1655                 * get_revision_1() runs out the commits, and
1656                 * we are done computing the boundaries.
1657                 * switch to boundary commits output mode.
1658                 */
1659                revs->boundary = 2;
1660                return get_revision(revs);
1661        }
1662
1663        /*
1664         * boundary commits are the commits that are parents of the
1665         * ones we got from get_revision_1() but they themselves are
1666         * not returned from get_revision_1().  Before returning
1667         * 'c', we need to mark its parents that they could be boundaries.
1668         */
1669
1670        for (l = c->parents; l; l = l->next) {
1671                struct object *p;
1672                p = &(l->item->object);
1673                if (p->flags & (CHILD_SHOWN | SHOWN))
1674                        continue;
1675                p->flags |= CHILD_SHOWN;
1676                gc_boundary(&revs->boundary_commits);
1677                add_object_array(p, NULL, &revs->boundary_commits);
1678        }
1679
1680        return c;
1681}