revision.con commit Merge branch 'nk/ref-doc' into maint (3503b8d)
   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 "graph.h"
  10#include "grep.h"
  11#include "reflog-walk.h"
  12#include "patch-ids.h"
  13#include "decorate.h"
  14#include "log-tree.h"
  15#include "string-list.h"
  16
  17volatile show_early_output_fn_t show_early_output;
  18
  19char *path_name(const struct name_path *path, const char *name)
  20{
  21        const struct name_path *p;
  22        char *n, *m;
  23        int nlen = strlen(name);
  24        int len = nlen + 1;
  25
  26        for (p = path; p; p = p->up) {
  27                if (p->elem_len)
  28                        len += p->elem_len + 1;
  29        }
  30        n = xmalloc(len);
  31        m = n + len - (nlen + 1);
  32        strcpy(m, name);
  33        for (p = path; p; p = p->up) {
  34                if (p->elem_len) {
  35                        m -= p->elem_len + 1;
  36                        memcpy(m, p->elem, p->elem_len);
  37                        m[p->elem_len] = '/';
  38                }
  39        }
  40        return n;
  41}
  42
  43void add_object(struct object *obj,
  44                struct object_array *p,
  45                struct name_path *path,
  46                const char *name)
  47{
  48        add_object_array(obj, path_name(path, name), p);
  49}
  50
  51static void mark_blob_uninteresting(struct blob *blob)
  52{
  53        if (!blob)
  54                return;
  55        if (blob->object.flags & UNINTERESTING)
  56                return;
  57        blob->object.flags |= UNINTERESTING;
  58}
  59
  60void mark_tree_uninteresting(struct tree *tree)
  61{
  62        struct tree_desc desc;
  63        struct name_entry entry;
  64        struct object *obj = &tree->object;
  65
  66        if (!tree)
  67                return;
  68        if (obj->flags & UNINTERESTING)
  69                return;
  70        obj->flags |= UNINTERESTING;
  71        if (!has_sha1_file(obj->sha1))
  72                return;
  73        if (parse_tree(tree) < 0)
  74                die("bad tree %s", sha1_to_hex(obj->sha1));
  75
  76        init_tree_desc(&desc, tree->buffer, tree->size);
  77        while (tree_entry(&desc, &entry)) {
  78                switch (object_type(entry.mode)) {
  79                case OBJ_TREE:
  80                        mark_tree_uninteresting(lookup_tree(entry.sha1));
  81                        break;
  82                case OBJ_BLOB:
  83                        mark_blob_uninteresting(lookup_blob(entry.sha1));
  84                        break;
  85                default:
  86                        /* Subproject commit - not in this repository */
  87                        break;
  88                }
  89        }
  90
  91        /*
  92         * We don't care about the tree any more
  93         * after it has been marked uninteresting.
  94         */
  95        free(tree->buffer);
  96        tree->buffer = NULL;
  97}
  98
  99void mark_parents_uninteresting(struct commit *commit)
 100{
 101        struct commit_list *parents = commit->parents;
 102
 103        while (parents) {
 104                struct commit *commit = parents->item;
 105                if (!(commit->object.flags & UNINTERESTING)) {
 106                        commit->object.flags |= UNINTERESTING;
 107
 108                        /*
 109                         * Normally we haven't parsed the parent
 110                         * yet, so we won't have a parent of a parent
 111                         * here. However, it may turn out that we've
 112                         * reached this commit some other way (where it
 113                         * wasn't uninteresting), in which case we need
 114                         * to mark its parents recursively too..
 115                         */
 116                        if (commit->parents)
 117                                mark_parents_uninteresting(commit);
 118                }
 119
 120                /*
 121                 * A missing commit is ok iff its parent is marked
 122                 * uninteresting.
 123                 *
 124                 * We just mark such a thing parsed, so that when
 125                 * it is popped next time around, we won't be trying
 126                 * to parse it and get an error.
 127                 */
 128                if (!has_sha1_file(commit->object.sha1))
 129                        commit->object.parsed = 1;
 130                parents = parents->next;
 131        }
 132}
 133
 134static void add_pending_object_with_mode(struct rev_info *revs, struct object *obj, const char *name, unsigned mode)
 135{
 136        if (!obj)
 137                return;
 138        if (revs->no_walk && (obj->flags & UNINTERESTING))
 139                revs->no_walk = 0;
 140        if (revs->reflog_info && obj->type == OBJ_COMMIT) {
 141                struct strbuf buf = STRBUF_INIT;
 142                int len = interpret_branch_name(name, &buf);
 143                int st;
 144
 145                if (0 < len && name[len] && buf.len)
 146                        strbuf_addstr(&buf, name + len);
 147                st = add_reflog_for_walk(revs->reflog_info,
 148                                         (struct commit *)obj,
 149                                         buf.buf[0] ? buf.buf: name);
 150                strbuf_release(&buf);
 151                if (st)
 152                        return;
 153        }
 154        add_object_array_with_mode(obj, name, &revs->pending, mode);
 155}
 156
 157void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
 158{
 159        add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
 160}
 161
 162void add_head_to_pending(struct rev_info *revs)
 163{
 164        unsigned char sha1[20];
 165        struct object *obj;
 166        if (get_sha1("HEAD", sha1))
 167                return;
 168        obj = parse_object(sha1);
 169        if (!obj)
 170                return;
 171        add_pending_object(revs, obj, "HEAD");
 172}
 173
 174static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
 175{
 176        struct object *object;
 177
 178        object = parse_object(sha1);
 179        if (!object) {
 180                if (revs->ignore_missing)
 181                        return object;
 182                die("bad object %s", name);
 183        }
 184        object->flags |= flags;
 185        return object;
 186}
 187
 188static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
 189{
 190        unsigned long flags = object->flags;
 191
 192        /*
 193         * Tag object? Look what it points to..
 194         */
 195        while (object->type == OBJ_TAG) {
 196                struct tag *tag = (struct tag *) object;
 197                if (revs->tag_objects && !(flags & UNINTERESTING))
 198                        add_pending_object(revs, object, tag->tag);
 199                if (!tag->tagged)
 200                        die("bad tag");
 201                object = parse_object(tag->tagged->sha1);
 202                if (!object) {
 203                        if (flags & UNINTERESTING)
 204                                return NULL;
 205                        die("bad object %s", sha1_to_hex(tag->tagged->sha1));
 206                }
 207        }
 208
 209        /*
 210         * Commit object? Just return it, we'll do all the complex
 211         * reachability crud.
 212         */
 213        if (object->type == OBJ_COMMIT) {
 214                struct commit *commit = (struct commit *)object;
 215                if (parse_commit(commit) < 0)
 216                        die("unable to parse commit %s", name);
 217                if (flags & UNINTERESTING) {
 218                        commit->object.flags |= UNINTERESTING;
 219                        mark_parents_uninteresting(commit);
 220                        revs->limited = 1;
 221                }
 222                if (revs->show_source && !commit->util)
 223                        commit->util = (void *) name;
 224                return commit;
 225        }
 226
 227        /*
 228         * Tree object? Either mark it uninteresting, or add it
 229         * to the list of objects to look at later..
 230         */
 231        if (object->type == OBJ_TREE) {
 232                struct tree *tree = (struct tree *)object;
 233                if (!revs->tree_objects)
 234                        return NULL;
 235                if (flags & UNINTERESTING) {
 236                        mark_tree_uninteresting(tree);
 237                        return NULL;
 238                }
 239                add_pending_object(revs, object, "");
 240                return NULL;
 241        }
 242
 243        /*
 244         * Blob object? You know the drill by now..
 245         */
 246        if (object->type == OBJ_BLOB) {
 247                struct blob *blob = (struct blob *)object;
 248                if (!revs->blob_objects)
 249                        return NULL;
 250                if (flags & UNINTERESTING) {
 251                        mark_blob_uninteresting(blob);
 252                        return NULL;
 253                }
 254                add_pending_object(revs, object, "");
 255                return NULL;
 256        }
 257        die("%s is unknown object", name);
 258}
 259
 260static int everybody_uninteresting(struct commit_list *orig)
 261{
 262        struct commit_list *list = orig;
 263        while (list) {
 264                struct commit *commit = list->item;
 265                list = list->next;
 266                if (commit->object.flags & UNINTERESTING)
 267                        continue;
 268                return 0;
 269        }
 270        return 1;
 271}
 272
 273/*
 274 * The goal is to get REV_TREE_NEW as the result only if the
 275 * diff consists of all '+' (and no other changes), REV_TREE_OLD
 276 * if the whole diff is removal of old data, and otherwise
 277 * REV_TREE_DIFFERENT (of course if the trees are the same we
 278 * want REV_TREE_SAME).
 279 * That means that once we get to REV_TREE_DIFFERENT, we do not
 280 * have to look any further.
 281 */
 282static int tree_difference = REV_TREE_SAME;
 283
 284static void file_add_remove(struct diff_options *options,
 285                    int addremove, unsigned mode,
 286                    const unsigned char *sha1,
 287                    const char *fullpath, unsigned dirty_submodule)
 288{
 289        int diff = addremove == '+' ? REV_TREE_NEW : REV_TREE_OLD;
 290
 291        tree_difference |= diff;
 292        if (tree_difference == REV_TREE_DIFFERENT)
 293                DIFF_OPT_SET(options, HAS_CHANGES);
 294}
 295
 296static void file_change(struct diff_options *options,
 297                 unsigned old_mode, unsigned new_mode,
 298                 const unsigned char *old_sha1,
 299                 const unsigned char *new_sha1,
 300                 const char *fullpath,
 301                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
 302{
 303        tree_difference = REV_TREE_DIFFERENT;
 304        DIFF_OPT_SET(options, HAS_CHANGES);
 305}
 306
 307static int rev_compare_tree(struct rev_info *revs, struct commit *parent, struct commit *commit)
 308{
 309        struct tree *t1 = parent->tree;
 310        struct tree *t2 = commit->tree;
 311
 312        if (!t1)
 313                return REV_TREE_NEW;
 314        if (!t2)
 315                return REV_TREE_OLD;
 316
 317        if (revs->simplify_by_decoration) {
 318                /*
 319                 * If we are simplifying by decoration, then the commit
 320                 * is worth showing if it has a tag pointing at it.
 321                 */
 322                if (lookup_decoration(&name_decoration, &commit->object))
 323                        return REV_TREE_DIFFERENT;
 324                /*
 325                 * A commit that is not pointed by a tag is uninteresting
 326                 * if we are not limited by path.  This means that you will
 327                 * see the usual "commits that touch the paths" plus any
 328                 * tagged commit by specifying both --simplify-by-decoration
 329                 * and pathspec.
 330                 */
 331                if (!revs->prune_data.nr)
 332                        return REV_TREE_SAME;
 333        }
 334
 335        tree_difference = REV_TREE_SAME;
 336        DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 337        if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
 338                           &revs->pruning) < 0)
 339                return REV_TREE_DIFFERENT;
 340        return tree_difference;
 341}
 342
 343static int rev_same_tree_as_empty(struct rev_info *revs, struct commit *commit)
 344{
 345        int retval;
 346        void *tree;
 347        unsigned long size;
 348        struct tree_desc empty, real;
 349        struct tree *t1 = commit->tree;
 350
 351        if (!t1)
 352                return 0;
 353
 354        tree = read_object_with_reference(t1->object.sha1, tree_type, &size, NULL);
 355        if (!tree)
 356                return 0;
 357        init_tree_desc(&real, tree, size);
 358        init_tree_desc(&empty, "", 0);
 359
 360        tree_difference = REV_TREE_SAME;
 361        DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 362        retval = diff_tree(&empty, &real, "", &revs->pruning);
 363        free(tree);
 364
 365        return retval >= 0 && (tree_difference == REV_TREE_SAME);
 366}
 367
 368static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 369{
 370        struct commit_list **pp, *parent;
 371        int tree_changed = 0, tree_same = 0;
 372
 373        /*
 374         * If we don't do pruning, everything is interesting
 375         */
 376        if (!revs->prune)
 377                return;
 378
 379        if (!commit->tree)
 380                return;
 381
 382        if (!commit->parents) {
 383                if (rev_same_tree_as_empty(revs, commit))
 384                        commit->object.flags |= TREESAME;
 385                return;
 386        }
 387
 388        /*
 389         * Normal non-merge commit? If we don't want to make the
 390         * history dense, we consider it always to be a change..
 391         */
 392        if (!revs->dense && !commit->parents->next)
 393                return;
 394
 395        pp = &commit->parents;
 396        while ((parent = *pp) != NULL) {
 397                struct commit *p = parent->item;
 398
 399                if (parse_commit(p) < 0)
 400                        die("cannot simplify commit %s (because of %s)",
 401                            sha1_to_hex(commit->object.sha1),
 402                            sha1_to_hex(p->object.sha1));
 403                switch (rev_compare_tree(revs, p, commit)) {
 404                case REV_TREE_SAME:
 405                        tree_same = 1;
 406                        if (!revs->simplify_history || (p->object.flags & UNINTERESTING)) {
 407                                /* Even if a merge with an uninteresting
 408                                 * side branch brought the entire change
 409                                 * we are interested in, we do not want
 410                                 * to lose the other branches of this
 411                                 * merge, so we just keep going.
 412                                 */
 413                                pp = &parent->next;
 414                                continue;
 415                        }
 416                        parent->next = NULL;
 417                        commit->parents = parent;
 418                        commit->object.flags |= TREESAME;
 419                        return;
 420
 421                case REV_TREE_NEW:
 422                        if (revs->remove_empty_trees &&
 423                            rev_same_tree_as_empty(revs, p)) {
 424                                /* We are adding all the specified
 425                                 * paths from this parent, so the
 426                                 * history beyond this parent is not
 427                                 * interesting.  Remove its parents
 428                                 * (they are grandparents for us).
 429                                 * IOW, we pretend this parent is a
 430                                 * "root" commit.
 431                                 */
 432                                if (parse_commit(p) < 0)
 433                                        die("cannot simplify commit %s (invalid %s)",
 434                                            sha1_to_hex(commit->object.sha1),
 435                                            sha1_to_hex(p->object.sha1));
 436                                p->parents = NULL;
 437                        }
 438                /* fallthrough */
 439                case REV_TREE_OLD:
 440                case REV_TREE_DIFFERENT:
 441                        tree_changed = 1;
 442                        pp = &parent->next;
 443                        continue;
 444                }
 445                die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
 446        }
 447        if (tree_changed && !tree_same)
 448                return;
 449        commit->object.flags |= TREESAME;
 450}
 451
 452static void commit_list_insert_by_date_cached(struct commit *p, struct commit_list **head,
 453                    struct commit_list *cached_base, struct commit_list **cache)
 454{
 455        struct commit_list *new_entry;
 456
 457        if (cached_base && p->date < cached_base->item->date)
 458                new_entry = commit_list_insert_by_date(p, &cached_base->next);
 459        else
 460                new_entry = commit_list_insert_by_date(p, head);
 461
 462        if (cache && (!*cache || p->date < (*cache)->item->date))
 463                *cache = new_entry;
 464}
 465
 466static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
 467                    struct commit_list **list, struct commit_list **cache_ptr)
 468{
 469        struct commit_list *parent = commit->parents;
 470        unsigned left_flag;
 471        struct commit_list *cached_base = cache_ptr ? *cache_ptr : NULL;
 472
 473        if (commit->object.flags & ADDED)
 474                return 0;
 475        commit->object.flags |= ADDED;
 476
 477        /*
 478         * If the commit is uninteresting, don't try to
 479         * prune parents - we want the maximal uninteresting
 480         * set.
 481         *
 482         * Normally we haven't parsed the parent
 483         * yet, so we won't have a parent of a parent
 484         * here. However, it may turn out that we've
 485         * reached this commit some other way (where it
 486         * wasn't uninteresting), in which case we need
 487         * to mark its parents recursively too..
 488         */
 489        if (commit->object.flags & UNINTERESTING) {
 490                while (parent) {
 491                        struct commit *p = parent->item;
 492                        parent = parent->next;
 493                        if (p)
 494                                p->object.flags |= UNINTERESTING;
 495                        if (parse_commit(p) < 0)
 496                                continue;
 497                        if (p->parents)
 498                                mark_parents_uninteresting(p);
 499                        if (p->object.flags & SEEN)
 500                                continue;
 501                        p->object.flags |= SEEN;
 502                        commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
 503                }
 504                return 0;
 505        }
 506
 507        /*
 508         * Ok, the commit wasn't uninteresting. Try to
 509         * simplify the commit history and find the parent
 510         * that has no differences in the path set if one exists.
 511         */
 512        try_to_simplify_commit(revs, commit);
 513
 514        if (revs->no_walk)
 515                return 0;
 516
 517        left_flag = (commit->object.flags & SYMMETRIC_LEFT);
 518
 519        for (parent = commit->parents; parent; parent = parent->next) {
 520                struct commit *p = parent->item;
 521
 522                if (parse_commit(p) < 0)
 523                        return -1;
 524                if (revs->show_source && !p->util)
 525                        p->util = commit->util;
 526                p->object.flags |= left_flag;
 527                if (!(p->object.flags & SEEN)) {
 528                        p->object.flags |= SEEN;
 529                        commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
 530                }
 531                if (revs->first_parent_only)
 532                        break;
 533        }
 534        return 0;
 535}
 536
 537static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
 538{
 539        struct commit_list *p;
 540        int left_count = 0, right_count = 0;
 541        int left_first;
 542        struct patch_ids ids;
 543        unsigned cherry_flag;
 544
 545        /* First count the commits on the left and on the right */
 546        for (p = list; p; p = p->next) {
 547                struct commit *commit = p->item;
 548                unsigned flags = commit->object.flags;
 549                if (flags & BOUNDARY)
 550                        ;
 551                else if (flags & SYMMETRIC_LEFT)
 552                        left_count++;
 553                else
 554                        right_count++;
 555        }
 556
 557        if (!left_count || !right_count)
 558                return;
 559
 560        left_first = left_count < right_count;
 561        init_patch_ids(&ids);
 562        ids.diffopts.pathspec = revs->diffopt.pathspec;
 563
 564        /* Compute patch-ids for one side */
 565        for (p = list; p; p = p->next) {
 566                struct commit *commit = p->item;
 567                unsigned flags = commit->object.flags;
 568
 569                if (flags & BOUNDARY)
 570                        continue;
 571                /*
 572                 * If we have fewer left, left_first is set and we omit
 573                 * commits on the right branch in this loop.  If we have
 574                 * fewer right, we skip the left ones.
 575                 */
 576                if (left_first != !!(flags & SYMMETRIC_LEFT))
 577                        continue;
 578                commit->util = add_commit_patch_id(commit, &ids);
 579        }
 580
 581        /* either cherry_mark or cherry_pick are true */
 582        cherry_flag = revs->cherry_mark ? PATCHSAME : SHOWN;
 583
 584        /* Check the other side */
 585        for (p = list; p; p = p->next) {
 586                struct commit *commit = p->item;
 587                struct patch_id *id;
 588                unsigned flags = commit->object.flags;
 589
 590                if (flags & BOUNDARY)
 591                        continue;
 592                /*
 593                 * If we have fewer left, left_first is set and we omit
 594                 * commits on the left branch in this loop.
 595                 */
 596                if (left_first == !!(flags & SYMMETRIC_LEFT))
 597                        continue;
 598
 599                /*
 600                 * Have we seen the same patch id?
 601                 */
 602                id = has_commit_patch_id(commit, &ids);
 603                if (!id)
 604                        continue;
 605                id->seen = 1;
 606                commit->object.flags |= cherry_flag;
 607        }
 608
 609        /* Now check the original side for seen ones */
 610        for (p = list; p; p = p->next) {
 611                struct commit *commit = p->item;
 612                struct patch_id *ent;
 613
 614                ent = commit->util;
 615                if (!ent)
 616                        continue;
 617                if (ent->seen)
 618                        commit->object.flags |= cherry_flag;
 619                commit->util = NULL;
 620        }
 621
 622        free_patch_ids(&ids);
 623}
 624
 625/* How many extra uninteresting commits we want to see.. */
 626#define SLOP 5
 627
 628static int still_interesting(struct commit_list *src, unsigned long date, int slop)
 629{
 630        /*
 631         * No source list at all? We're definitely done..
 632         */
 633        if (!src)
 634                return 0;
 635
 636        /*
 637         * Does the destination list contain entries with a date
 638         * before the source list? Definitely _not_ done.
 639         */
 640        if (date < src->item->date)
 641                return SLOP;
 642
 643        /*
 644         * Does the source list still have interesting commits in
 645         * it? Definitely not done..
 646         */
 647        if (!everybody_uninteresting(src))
 648                return SLOP;
 649
 650        /* Ok, we're closing in.. */
 651        return slop-1;
 652}
 653
 654/*
 655 * "rev-list --ancestry-path A..B" computes commits that are ancestors
 656 * of B but not ancestors of A but further limits the result to those
 657 * that are descendants of A.  This takes the list of bottom commits and
 658 * the result of "A..B" without --ancestry-path, and limits the latter
 659 * further to the ones that can reach one of the commits in "bottom".
 660 */
 661static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *list)
 662{
 663        struct commit_list *p;
 664        struct commit_list *rlist = NULL;
 665        int made_progress;
 666
 667        /*
 668         * Reverse the list so that it will be likely that we would
 669         * process parents before children.
 670         */
 671        for (p = list; p; p = p->next)
 672                commit_list_insert(p->item, &rlist);
 673
 674        for (p = bottom; p; p = p->next)
 675                p->item->object.flags |= TMP_MARK;
 676
 677        /*
 678         * Mark the ones that can reach bottom commits in "list",
 679         * in a bottom-up fashion.
 680         */
 681        do {
 682                made_progress = 0;
 683                for (p = rlist; p; p = p->next) {
 684                        struct commit *c = p->item;
 685                        struct commit_list *parents;
 686                        if (c->object.flags & (TMP_MARK | UNINTERESTING))
 687                                continue;
 688                        for (parents = c->parents;
 689                             parents;
 690                             parents = parents->next) {
 691                                if (!(parents->item->object.flags & TMP_MARK))
 692                                        continue;
 693                                c->object.flags |= TMP_MARK;
 694                                made_progress = 1;
 695                                break;
 696                        }
 697                }
 698        } while (made_progress);
 699
 700        /*
 701         * NEEDSWORK: decide if we want to remove parents that are
 702         * not marked with TMP_MARK from commit->parents for commits
 703         * in the resulting list.  We may not want to do that, though.
 704         */
 705
 706        /*
 707         * The ones that are not marked with TMP_MARK are uninteresting
 708         */
 709        for (p = list; p; p = p->next) {
 710                struct commit *c = p->item;
 711                if (c->object.flags & TMP_MARK)
 712                        continue;
 713                c->object.flags |= UNINTERESTING;
 714        }
 715
 716        /* We are done with the TMP_MARK */
 717        for (p = list; p; p = p->next)
 718                p->item->object.flags &= ~TMP_MARK;
 719        for (p = bottom; p; p = p->next)
 720                p->item->object.flags &= ~TMP_MARK;
 721        free_commit_list(rlist);
 722}
 723
 724/*
 725 * Before walking the history, keep the set of "negative" refs the
 726 * caller has asked to exclude.
 727 *
 728 * This is used to compute "rev-list --ancestry-path A..B", as we need
 729 * to filter the result of "A..B" further to the ones that can actually
 730 * reach A.
 731 */
 732static struct commit_list *collect_bottom_commits(struct commit_list *list)
 733{
 734        struct commit_list *elem, *bottom = NULL;
 735        for (elem = list; elem; elem = elem->next)
 736                if (elem->item->object.flags & UNINTERESTING)
 737                        commit_list_insert(elem->item, &bottom);
 738        return bottom;
 739}
 740
 741/* Assumes either left_only or right_only is set */
 742static void limit_left_right(struct commit_list *list, struct rev_info *revs)
 743{
 744        struct commit_list *p;
 745
 746        for (p = list; p; p = p->next) {
 747                struct commit *commit = p->item;
 748
 749                if (revs->right_only) {
 750                        if (commit->object.flags & SYMMETRIC_LEFT)
 751                                commit->object.flags |= SHOWN;
 752                } else  /* revs->left_only is set */
 753                        if (!(commit->object.flags & SYMMETRIC_LEFT))
 754                                commit->object.flags |= SHOWN;
 755        }
 756}
 757
 758static int limit_list(struct rev_info *revs)
 759{
 760        int slop = SLOP;
 761        unsigned long date = ~0ul;
 762        struct commit_list *list = revs->commits;
 763        struct commit_list *newlist = NULL;
 764        struct commit_list **p = &newlist;
 765        struct commit_list *bottom = NULL;
 766
 767        if (revs->ancestry_path) {
 768                bottom = collect_bottom_commits(list);
 769                if (!bottom)
 770                        die("--ancestry-path given but there are no bottom commits");
 771        }
 772
 773        while (list) {
 774                struct commit_list *entry = list;
 775                struct commit *commit = list->item;
 776                struct object *obj = &commit->object;
 777                show_early_output_fn_t show;
 778
 779                list = list->next;
 780                free(entry);
 781
 782                if (revs->max_age != -1 && (commit->date < revs->max_age))
 783                        obj->flags |= UNINTERESTING;
 784                if (add_parents_to_list(revs, commit, &list, NULL) < 0)
 785                        return -1;
 786                if (obj->flags & UNINTERESTING) {
 787                        mark_parents_uninteresting(commit);
 788                        if (revs->show_all)
 789                                p = &commit_list_insert(commit, p)->next;
 790                        slop = still_interesting(list, date, slop);
 791                        if (slop)
 792                                continue;
 793                        /* If showing all, add the whole pending list to the end */
 794                        if (revs->show_all)
 795                                *p = list;
 796                        break;
 797                }
 798                if (revs->min_age != -1 && (commit->date > revs->min_age))
 799                        continue;
 800                date = commit->date;
 801                p = &commit_list_insert(commit, p)->next;
 802
 803                show = show_early_output;
 804                if (!show)
 805                        continue;
 806
 807                show(revs, newlist);
 808                show_early_output = NULL;
 809        }
 810        if (revs->cherry_pick || revs->cherry_mark)
 811                cherry_pick_list(newlist, revs);
 812
 813        if (revs->left_only || revs->right_only)
 814                limit_left_right(newlist, revs);
 815
 816        if (bottom) {
 817                limit_to_ancestry(bottom, newlist);
 818                free_commit_list(bottom);
 819        }
 820
 821        revs->commits = newlist;
 822        return 0;
 823}
 824
 825struct all_refs_cb {
 826        int all_flags;
 827        int warned_bad_reflog;
 828        struct rev_info *all_revs;
 829        const char *name_for_errormsg;
 830};
 831
 832static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 833{
 834        struct all_refs_cb *cb = cb_data;
 835        struct object *object = get_reference(cb->all_revs, path, sha1,
 836                                              cb->all_flags);
 837        add_pending_object(cb->all_revs, object, path);
 838        return 0;
 839}
 840
 841static void init_all_refs_cb(struct all_refs_cb *cb, struct rev_info *revs,
 842        unsigned flags)
 843{
 844        cb->all_revs = revs;
 845        cb->all_flags = flags;
 846}
 847
 848static void handle_refs(const char *submodule, struct rev_info *revs, unsigned flags,
 849                int (*for_each)(const char *, each_ref_fn, void *))
 850{
 851        struct all_refs_cb cb;
 852        init_all_refs_cb(&cb, revs, flags);
 853        for_each(submodule, handle_one_ref, &cb);
 854}
 855
 856static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
 857{
 858        struct all_refs_cb *cb = cb_data;
 859        if (!is_null_sha1(sha1)) {
 860                struct object *o = parse_object(sha1);
 861                if (o) {
 862                        o->flags |= cb->all_flags;
 863                        add_pending_object(cb->all_revs, o, "");
 864                }
 865                else if (!cb->warned_bad_reflog) {
 866                        warning("reflog of '%s' references pruned commits",
 867                                cb->name_for_errormsg);
 868                        cb->warned_bad_reflog = 1;
 869                }
 870        }
 871}
 872
 873static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 874                const char *email, unsigned long timestamp, int tz,
 875                const char *message, void *cb_data)
 876{
 877        handle_one_reflog_commit(osha1, cb_data);
 878        handle_one_reflog_commit(nsha1, cb_data);
 879        return 0;
 880}
 881
 882static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 883{
 884        struct all_refs_cb *cb = cb_data;
 885        cb->warned_bad_reflog = 0;
 886        cb->name_for_errormsg = path;
 887        for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
 888        return 0;
 889}
 890
 891static void handle_reflog(struct rev_info *revs, unsigned flags)
 892{
 893        struct all_refs_cb cb;
 894        cb.all_revs = revs;
 895        cb.all_flags = flags;
 896        for_each_reflog(handle_one_reflog, &cb);
 897}
 898
 899static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
 900{
 901        unsigned char sha1[20];
 902        struct object *it;
 903        struct commit *commit;
 904        struct commit_list *parents;
 905
 906        if (*arg == '^') {
 907                flags ^= UNINTERESTING;
 908                arg++;
 909        }
 910        if (get_sha1(arg, sha1))
 911                return 0;
 912        while (1) {
 913                it = get_reference(revs, arg, sha1, 0);
 914                if (!it && revs->ignore_missing)
 915                        return 0;
 916                if (it->type != OBJ_TAG)
 917                        break;
 918                if (!((struct tag*)it)->tagged)
 919                        return 0;
 920                hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
 921        }
 922        if (it->type != OBJ_COMMIT)
 923                return 0;
 924        commit = (struct commit *)it;
 925        for (parents = commit->parents; parents; parents = parents->next) {
 926                it = &parents->item->object;
 927                it->flags |= flags;
 928                add_pending_object(revs, it, arg);
 929        }
 930        return 1;
 931}
 932
 933void init_revisions(struct rev_info *revs, const char *prefix)
 934{
 935        memset(revs, 0, sizeof(*revs));
 936
 937        revs->abbrev = DEFAULT_ABBREV;
 938        revs->ignore_merges = 1;
 939        revs->simplify_history = 1;
 940        DIFF_OPT_SET(&revs->pruning, RECURSIVE);
 941        DIFF_OPT_SET(&revs->pruning, QUICK);
 942        revs->pruning.add_remove = file_add_remove;
 943        revs->pruning.change = file_change;
 944        revs->lifo = 1;
 945        revs->dense = 1;
 946        revs->prefix = prefix;
 947        revs->max_age = -1;
 948        revs->min_age = -1;
 949        revs->skip_count = -1;
 950        revs->max_count = -1;
 951        revs->max_parents = -1;
 952
 953        revs->commit_format = CMIT_FMT_DEFAULT;
 954
 955        revs->grep_filter.status_only = 1;
 956        revs->grep_filter.pattern_tail = &(revs->grep_filter.pattern_list);
 957        revs->grep_filter.header_tail = &(revs->grep_filter.header_list);
 958        revs->grep_filter.regflags = REG_NEWLINE;
 959
 960        diff_setup(&revs->diffopt);
 961        if (prefix && !revs->diffopt.prefix) {
 962                revs->diffopt.prefix = prefix;
 963                revs->diffopt.prefix_length = strlen(prefix);
 964        }
 965
 966        revs->notes_opt.use_default_notes = -1;
 967}
 968
 969static void add_pending_commit_list(struct rev_info *revs,
 970                                    struct commit_list *commit_list,
 971                                    unsigned int flags)
 972{
 973        while (commit_list) {
 974                struct object *object = &commit_list->item->object;
 975                object->flags |= flags;
 976                add_pending_object(revs, object, sha1_to_hex(object->sha1));
 977                commit_list = commit_list->next;
 978        }
 979}
 980
 981static void prepare_show_merge(struct rev_info *revs)
 982{
 983        struct commit_list *bases;
 984        struct commit *head, *other;
 985        unsigned char sha1[20];
 986        const char **prune = NULL;
 987        int i, prune_num = 1; /* counting terminating NULL */
 988
 989        if (get_sha1("HEAD", sha1) || !(head = lookup_commit(sha1)))
 990                die("--merge without HEAD?");
 991        if (get_sha1("MERGE_HEAD", sha1) || !(other = lookup_commit(sha1)))
 992                die("--merge without MERGE_HEAD?");
 993        add_pending_object(revs, &head->object, "HEAD");
 994        add_pending_object(revs, &other->object, "MERGE_HEAD");
 995        bases = get_merge_bases(head, other, 1);
 996        add_pending_commit_list(revs, bases, UNINTERESTING);
 997        free_commit_list(bases);
 998        head->object.flags |= SYMMETRIC_LEFT;
 999
1000        if (!active_nr)
1001                read_cache();
1002        for (i = 0; i < active_nr; i++) {
1003                struct cache_entry *ce = active_cache[i];
1004                if (!ce_stage(ce))
1005                        continue;
1006                if (ce_path_match(ce, &revs->prune_data)) {
1007                        prune_num++;
1008                        prune = xrealloc(prune, sizeof(*prune) * prune_num);
1009                        prune[prune_num-2] = ce->name;
1010                        prune[prune_num-1] = NULL;
1011                }
1012                while ((i+1 < active_nr) &&
1013                       ce_same_name(ce, active_cache[i+1]))
1014                        i++;
1015        }
1016        free_pathspec(&revs->prune_data);
1017        init_pathspec(&revs->prune_data, prune);
1018        revs->limited = 1;
1019}
1020
1021int handle_revision_arg(const char *arg, struct rev_info *revs,
1022                        int flags,
1023                        int cant_be_filename)
1024{
1025        unsigned mode;
1026        char *dotdot;
1027        struct object *object;
1028        unsigned char sha1[20];
1029        int local_flags;
1030
1031        dotdot = strstr(arg, "..");
1032        if (dotdot) {
1033                unsigned char from_sha1[20];
1034                const char *next = dotdot + 2;
1035                const char *this = arg;
1036                int symmetric = *next == '.';
1037                unsigned int flags_exclude = flags ^ UNINTERESTING;
1038
1039                *dotdot = 0;
1040                next += symmetric;
1041
1042                if (!*next)
1043                        next = "HEAD";
1044                if (dotdot == arg)
1045                        this = "HEAD";
1046                if (!get_sha1(this, from_sha1) &&
1047                    !get_sha1(next, sha1)) {
1048                        struct commit *a, *b;
1049                        struct commit_list *exclude;
1050
1051                        a = lookup_commit_reference(from_sha1);
1052                        b = lookup_commit_reference(sha1);
1053                        if (!a || !b) {
1054                                if (revs->ignore_missing)
1055                                        return 0;
1056                                die(symmetric ?
1057                                    "Invalid symmetric difference expression %s...%s" :
1058                                    "Invalid revision range %s..%s",
1059                                    arg, next);
1060                        }
1061
1062                        if (!cant_be_filename) {
1063                                *dotdot = '.';
1064                                verify_non_filename(revs->prefix, arg);
1065                        }
1066
1067                        if (symmetric) {
1068                                exclude = get_merge_bases(a, b, 1);
1069                                add_pending_commit_list(revs, exclude,
1070                                                        flags_exclude);
1071                                free_commit_list(exclude);
1072                                a->object.flags |= flags | SYMMETRIC_LEFT;
1073                        } else
1074                                a->object.flags |= flags_exclude;
1075                        b->object.flags |= flags;
1076                        add_pending_object(revs, &a->object, this);
1077                        add_pending_object(revs, &b->object, next);
1078                        return 0;
1079                }
1080                *dotdot = '.';
1081        }
1082        dotdot = strstr(arg, "^@");
1083        if (dotdot && !dotdot[2]) {
1084                *dotdot = 0;
1085                if (add_parents_only(revs, arg, flags))
1086                        return 0;
1087                *dotdot = '^';
1088        }
1089        dotdot = strstr(arg, "^!");
1090        if (dotdot && !dotdot[2]) {
1091                *dotdot = 0;
1092                if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
1093                        *dotdot = '^';
1094        }
1095
1096        local_flags = 0;
1097        if (*arg == '^') {
1098                local_flags = UNINTERESTING;
1099                arg++;
1100        }
1101        if (get_sha1_with_mode(arg, sha1, &mode))
1102                return revs->ignore_missing ? 0 : -1;
1103        if (!cant_be_filename)
1104                verify_non_filename(revs->prefix, arg);
1105        object = get_reference(revs, arg, sha1, flags ^ local_flags);
1106        add_pending_object_with_mode(revs, object, arg, mode);
1107        return 0;
1108}
1109
1110struct cmdline_pathspec {
1111        int alloc;
1112        int nr;
1113        const char **path;
1114};
1115
1116static void append_prune_data(struct cmdline_pathspec *prune, const char **av)
1117{
1118        while (*av) {
1119                ALLOC_GROW(prune->path, prune->nr+1, prune->alloc);
1120                prune->path[prune->nr++] = *(av++);
1121        }
1122}
1123
1124static void read_pathspec_from_stdin(struct rev_info *revs, struct strbuf *sb,
1125                                     struct cmdline_pathspec *prune)
1126{
1127        while (strbuf_getwholeline(sb, stdin, '\n') != EOF) {
1128                int len = sb->len;
1129                if (len && sb->buf[len - 1] == '\n')
1130                        sb->buf[--len] = '\0';
1131                ALLOC_GROW(prune->path, prune->nr+1, prune->alloc);
1132                prune->path[prune->nr++] = xstrdup(sb->buf);
1133        }
1134}
1135
1136static void read_revisions_from_stdin(struct rev_info *revs,
1137                                      struct cmdline_pathspec *prune)
1138{
1139        struct strbuf sb;
1140        int seen_dashdash = 0;
1141
1142        strbuf_init(&sb, 1000);
1143        while (strbuf_getwholeline(&sb, stdin, '\n') != EOF) {
1144                int len = sb.len;
1145                if (len && sb.buf[len - 1] == '\n')
1146                        sb.buf[--len] = '\0';
1147                if (!len)
1148                        break;
1149                if (sb.buf[0] == '-') {
1150                        if (len == 2 && sb.buf[1] == '-') {
1151                                seen_dashdash = 1;
1152                                break;
1153                        }
1154                        die("options not supported in --stdin mode");
1155                }
1156                if (handle_revision_arg(sb.buf, revs, 0, 1))
1157                        die("bad revision '%s'", sb.buf);
1158        }
1159        if (seen_dashdash)
1160                read_pathspec_from_stdin(revs, &sb, prune);
1161        strbuf_release(&sb);
1162}
1163
1164static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
1165{
1166        append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
1167}
1168
1169static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
1170{
1171        append_header_grep_pattern(&revs->grep_filter, field, pattern);
1172}
1173
1174static void add_message_grep(struct rev_info *revs, const char *pattern)
1175{
1176        add_grep(revs, pattern, GREP_PATTERN_BODY);
1177}
1178
1179static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
1180                               int *unkc, const char **unkv)
1181{
1182        const char *arg = argv[0];
1183        const char *optarg;
1184        int argcount;
1185
1186        /* pseudo revision arguments */
1187        if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
1188            !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
1189            !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
1190            !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
1191            !strcmp(arg, "--bisect") || !prefixcmp(arg, "--glob=") ||
1192            !prefixcmp(arg, "--branches=") || !prefixcmp(arg, "--tags=") ||
1193            !prefixcmp(arg, "--remotes="))
1194        {
1195                unkv[(*unkc)++] = arg;
1196                return 1;
1197        }
1198
1199        if ((argcount = parse_long_opt("max-count", argv, &optarg))) {
1200                revs->max_count = atoi(optarg);
1201                revs->no_walk = 0;
1202                return argcount;
1203        } else if ((argcount = parse_long_opt("skip", argv, &optarg))) {
1204                revs->skip_count = atoi(optarg);
1205                return argcount;
1206        } else if ((*arg == '-') && isdigit(arg[1])) {
1207        /* accept -<digit>, like traditional "head" */
1208                revs->max_count = atoi(arg + 1);
1209                revs->no_walk = 0;
1210        } else if (!strcmp(arg, "-n")) {
1211                if (argc <= 1)
1212                        return error("-n requires an argument");
1213                revs->max_count = atoi(argv[1]);
1214                revs->no_walk = 0;
1215                return 2;
1216        } else if (!prefixcmp(arg, "-n")) {
1217                revs->max_count = atoi(arg + 2);
1218                revs->no_walk = 0;
1219        } else if ((argcount = parse_long_opt("max-age", argv, &optarg))) {
1220                revs->max_age = atoi(optarg);
1221                return argcount;
1222        } else if ((argcount = parse_long_opt("since", argv, &optarg))) {
1223                revs->max_age = approxidate(optarg);
1224                return argcount;
1225        } else if ((argcount = parse_long_opt("after", argv, &optarg))) {
1226                revs->max_age = approxidate(optarg);
1227                return argcount;
1228        } else if ((argcount = parse_long_opt("min-age", argv, &optarg))) {
1229                revs->min_age = atoi(optarg);
1230                return argcount;
1231        } else if ((argcount = parse_long_opt("before", argv, &optarg))) {
1232                revs->min_age = approxidate(optarg);
1233                return argcount;
1234        } else if ((argcount = parse_long_opt("until", argv, &optarg))) {
1235                revs->min_age = approxidate(optarg);
1236                return argcount;
1237        } else if (!strcmp(arg, "--first-parent")) {
1238                revs->first_parent_only = 1;
1239        } else if (!strcmp(arg, "--ancestry-path")) {
1240                revs->ancestry_path = 1;
1241                revs->simplify_history = 0;
1242                revs->limited = 1;
1243        } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
1244                init_reflog_walk(&revs->reflog_info);
1245        } else if (!strcmp(arg, "--default")) {
1246                if (argc <= 1)
1247                        return error("bad --default argument");
1248                revs->def = argv[1];
1249                return 2;
1250        } else if (!strcmp(arg, "--merge")) {
1251                revs->show_merge = 1;
1252        } else if (!strcmp(arg, "--topo-order")) {
1253                revs->lifo = 1;
1254                revs->topo_order = 1;
1255        } else if (!strcmp(arg, "--simplify-merges")) {
1256                revs->simplify_merges = 1;
1257                revs->rewrite_parents = 1;
1258                revs->simplify_history = 0;
1259                revs->limited = 1;
1260        } else if (!strcmp(arg, "--simplify-by-decoration")) {
1261                revs->simplify_merges = 1;
1262                revs->rewrite_parents = 1;
1263                revs->simplify_history = 0;
1264                revs->simplify_by_decoration = 1;
1265                revs->limited = 1;
1266                revs->prune = 1;
1267                load_ref_decorations(DECORATE_SHORT_REFS);
1268        } else if (!strcmp(arg, "--date-order")) {
1269                revs->lifo = 0;
1270                revs->topo_order = 1;
1271        } else if (!prefixcmp(arg, "--early-output")) {
1272                int count = 100;
1273                switch (arg[14]) {
1274                case '=':
1275                        count = atoi(arg+15);
1276                        /* Fallthrough */
1277                case 0:
1278                        revs->topo_order = 1;
1279                       revs->early_output = count;
1280                }
1281        } else if (!strcmp(arg, "--parents")) {
1282                revs->rewrite_parents = 1;
1283                revs->print_parents = 1;
1284        } else if (!strcmp(arg, "--dense")) {
1285                revs->dense = 1;
1286        } else if (!strcmp(arg, "--sparse")) {
1287                revs->dense = 0;
1288        } else if (!strcmp(arg, "--show-all")) {
1289                revs->show_all = 1;
1290        } else if (!strcmp(arg, "--remove-empty")) {
1291                revs->remove_empty_trees = 1;
1292        } else if (!strcmp(arg, "--merges")) {
1293                revs->min_parents = 2;
1294        } else if (!strcmp(arg, "--no-merges")) {
1295                revs->max_parents = 1;
1296        } else if (!prefixcmp(arg, "--min-parents=")) {
1297                revs->min_parents = atoi(arg+14);
1298        } else if (!prefixcmp(arg, "--no-min-parents")) {
1299                revs->min_parents = 0;
1300        } else if (!prefixcmp(arg, "--max-parents=")) {
1301                revs->max_parents = atoi(arg+14);
1302        } else if (!prefixcmp(arg, "--no-max-parents")) {
1303                revs->max_parents = -1;
1304        } else if (!strcmp(arg, "--boundary")) {
1305                revs->boundary = 1;
1306        } else if (!strcmp(arg, "--left-right")) {
1307                revs->left_right = 1;
1308        } else if (!strcmp(arg, "--left-only")) {
1309                if (revs->right_only)
1310                        die("--left-only is incompatible with --right-only"
1311                            " or --cherry");
1312                revs->left_only = 1;
1313        } else if (!strcmp(arg, "--right-only")) {
1314                if (revs->left_only)
1315                        die("--right-only is incompatible with --left-only");
1316                revs->right_only = 1;
1317        } else if (!strcmp(arg, "--cherry")) {
1318                if (revs->left_only)
1319                        die("--cherry is incompatible with --left-only");
1320                revs->cherry_mark = 1;
1321                revs->right_only = 1;
1322                revs->max_parents = 1;
1323                revs->limited = 1;
1324        } else if (!strcmp(arg, "--count")) {
1325                revs->count = 1;
1326        } else if (!strcmp(arg, "--cherry-mark")) {
1327                if (revs->cherry_pick)
1328                        die("--cherry-mark is incompatible with --cherry-pick");
1329                revs->cherry_mark = 1;
1330                revs->limited = 1; /* needs limit_list() */
1331        } else if (!strcmp(arg, "--cherry-pick")) {
1332                if (revs->cherry_mark)
1333                        die("--cherry-pick is incompatible with --cherry-mark");
1334                revs->cherry_pick = 1;
1335                revs->limited = 1;
1336        } else if (!strcmp(arg, "--objects")) {
1337                revs->tag_objects = 1;
1338                revs->tree_objects = 1;
1339                revs->blob_objects = 1;
1340        } else if (!strcmp(arg, "--objects-edge")) {
1341                revs->tag_objects = 1;
1342                revs->tree_objects = 1;
1343                revs->blob_objects = 1;
1344                revs->edge_hint = 1;
1345        } else if (!strcmp(arg, "--unpacked")) {
1346                revs->unpacked = 1;
1347        } else if (!prefixcmp(arg, "--unpacked=")) {
1348                die("--unpacked=<packfile> no longer supported.");
1349        } else if (!strcmp(arg, "-r")) {
1350                revs->diff = 1;
1351                DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1352        } else if (!strcmp(arg, "-t")) {
1353                revs->diff = 1;
1354                DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1355                DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1356        } else if (!strcmp(arg, "-m")) {
1357                revs->ignore_merges = 0;
1358        } else if (!strcmp(arg, "-c")) {
1359                revs->diff = 1;
1360                revs->dense_combined_merges = 0;
1361                revs->combine_merges = 1;
1362        } else if (!strcmp(arg, "--cc")) {
1363                revs->diff = 1;
1364                revs->dense_combined_merges = 1;
1365                revs->combine_merges = 1;
1366        } else if (!strcmp(arg, "-v")) {
1367                revs->verbose_header = 1;
1368        } else if (!strcmp(arg, "--pretty")) {
1369                revs->verbose_header = 1;
1370                revs->pretty_given = 1;
1371                get_commit_format(arg+8, revs);
1372        } else if (!prefixcmp(arg, "--pretty=") || !prefixcmp(arg, "--format=")) {
1373                /*
1374                 * Detached form ("--pretty X" as opposed to "--pretty=X")
1375                 * not allowed, since the argument is optional.
1376                 */
1377                revs->verbose_header = 1;
1378                revs->pretty_given = 1;
1379                get_commit_format(arg+9, revs);
1380        } else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
1381                revs->show_notes = 1;
1382                revs->show_notes_given = 1;
1383                revs->notes_opt.use_default_notes = 1;
1384        } else if (!prefixcmp(arg, "--show-notes=") ||
1385                   !prefixcmp(arg, "--notes=")) {
1386                struct strbuf buf = STRBUF_INIT;
1387                revs->show_notes = 1;
1388                revs->show_notes_given = 1;
1389                if (!prefixcmp(arg, "--show-notes")) {
1390                        if (revs->notes_opt.use_default_notes < 0)
1391                                revs->notes_opt.use_default_notes = 1;
1392                        strbuf_addstr(&buf, arg+13);
1393                }
1394                else
1395                        strbuf_addstr(&buf, arg+8);
1396                expand_notes_ref(&buf);
1397                string_list_append(&revs->notes_opt.extra_notes_refs,
1398                                   strbuf_detach(&buf, NULL));
1399        } else if (!strcmp(arg, "--no-notes")) {
1400                revs->show_notes = 0;
1401                revs->show_notes_given = 1;
1402                revs->notes_opt.use_default_notes = -1;
1403                /* we have been strdup'ing ourselves, so trick
1404                 * string_list into free()ing strings */
1405                revs->notes_opt.extra_notes_refs.strdup_strings = 1;
1406                string_list_clear(&revs->notes_opt.extra_notes_refs, 0);
1407                revs->notes_opt.extra_notes_refs.strdup_strings = 0;
1408        } else if (!strcmp(arg, "--standard-notes")) {
1409                revs->show_notes_given = 1;
1410                revs->notes_opt.use_default_notes = 1;
1411        } else if (!strcmp(arg, "--no-standard-notes")) {
1412                revs->notes_opt.use_default_notes = 0;
1413        } else if (!strcmp(arg, "--oneline")) {
1414                revs->verbose_header = 1;
1415                get_commit_format("oneline", revs);
1416                revs->pretty_given = 1;
1417                revs->abbrev_commit = 1;
1418        } else if (!strcmp(arg, "--graph")) {
1419                revs->topo_order = 1;
1420                revs->rewrite_parents = 1;
1421                revs->graph = graph_init(revs);
1422        } else if (!strcmp(arg, "--root")) {
1423                revs->show_root_diff = 1;
1424        } else if (!strcmp(arg, "--no-commit-id")) {
1425                revs->no_commit_id = 1;
1426        } else if (!strcmp(arg, "--always")) {
1427                revs->always_show_header = 1;
1428        } else if (!strcmp(arg, "--no-abbrev")) {
1429                revs->abbrev = 0;
1430        } else if (!strcmp(arg, "--abbrev")) {
1431                revs->abbrev = DEFAULT_ABBREV;
1432        } else if (!prefixcmp(arg, "--abbrev=")) {
1433                revs->abbrev = strtoul(arg + 9, NULL, 10);
1434                if (revs->abbrev < MINIMUM_ABBREV)
1435                        revs->abbrev = MINIMUM_ABBREV;
1436                else if (revs->abbrev > 40)
1437                        revs->abbrev = 40;
1438        } else if (!strcmp(arg, "--abbrev-commit")) {
1439                revs->abbrev_commit = 1;
1440                revs->abbrev_commit_given = 1;
1441        } else if (!strcmp(arg, "--no-abbrev-commit")) {
1442                revs->abbrev_commit = 0;
1443        } else if (!strcmp(arg, "--full-diff")) {
1444                revs->diff = 1;
1445                revs->full_diff = 1;
1446        } else if (!strcmp(arg, "--full-history")) {
1447                revs->simplify_history = 0;
1448        } else if (!strcmp(arg, "--relative-date")) {
1449                revs->date_mode = DATE_RELATIVE;
1450                revs->date_mode_explicit = 1;
1451        } else if ((argcount = parse_long_opt("date", argv, &optarg))) {
1452                revs->date_mode = parse_date_format(optarg);
1453                revs->date_mode_explicit = 1;
1454                return argcount;
1455        } else if (!strcmp(arg, "--log-size")) {
1456                revs->show_log_size = 1;
1457        }
1458        /*
1459         * Grepping the commit log
1460         */
1461        else if ((argcount = parse_long_opt("author", argv, &optarg))) {
1462                add_header_grep(revs, GREP_HEADER_AUTHOR, optarg);
1463                return argcount;
1464        } else if ((argcount = parse_long_opt("committer", argv, &optarg))) {
1465                add_header_grep(revs, GREP_HEADER_COMMITTER, optarg);
1466                return argcount;
1467        } else if ((argcount = parse_long_opt("grep", argv, &optarg))) {
1468                add_message_grep(revs, optarg);
1469                return argcount;
1470        } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
1471                revs->grep_filter.regflags |= REG_EXTENDED;
1472        } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
1473                revs->grep_filter.regflags |= REG_ICASE;
1474        } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
1475                revs->grep_filter.fixed = 1;
1476        } else if (!strcmp(arg, "--all-match")) {
1477                revs->grep_filter.all_match = 1;
1478        } else if ((argcount = parse_long_opt("encoding", argv, &optarg))) {
1479                if (strcmp(optarg, "none"))
1480                        git_log_output_encoding = xstrdup(optarg);
1481                else
1482                        git_log_output_encoding = "";
1483                return argcount;
1484        } else if (!strcmp(arg, "--reverse")) {
1485                revs->reverse ^= 1;
1486        } else if (!strcmp(arg, "--children")) {
1487                revs->children.name = "children";
1488                revs->limited = 1;
1489        } else if (!strcmp(arg, "--ignore-missing")) {
1490                revs->ignore_missing = 1;
1491        } else {
1492                int opts = diff_opt_parse(&revs->diffopt, argv, argc);
1493                if (!opts)
1494                        unkv[(*unkc)++] = arg;
1495                return opts;
1496        }
1497
1498        return 1;
1499}
1500
1501void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
1502                        const struct option *options,
1503                        const char * const usagestr[])
1504{
1505        int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
1506                                    &ctx->cpidx, ctx->out);
1507        if (n <= 0) {
1508                error("unknown option `%s'", ctx->argv[0]);
1509                usage_with_options(usagestr, options);
1510        }
1511        ctx->argv += n;
1512        ctx->argc -= n;
1513}
1514
1515static int for_each_bad_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1516{
1517        return for_each_ref_in_submodule(submodule, "refs/bisect/bad", fn, cb_data);
1518}
1519
1520static int for_each_good_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1521{
1522        return for_each_ref_in_submodule(submodule, "refs/bisect/good", fn, cb_data);
1523}
1524
1525static int handle_revision_pseudo_opt(const char *submodule,
1526                                struct rev_info *revs,
1527                                int argc, const char **argv, int *flags)
1528{
1529        const char *arg = argv[0];
1530        const char *optarg;
1531        int argcount;
1532
1533        /*
1534         * NOTE!
1535         *
1536         * Commands like "git shortlog" will not accept the options below
1537         * unless parse_revision_opt queues them (as opposed to erroring
1538         * out).
1539         *
1540         * When implementing your new pseudo-option, remember to
1541         * register it in the list at the top of handle_revision_opt.
1542         */
1543        if (!strcmp(arg, "--all")) {
1544                handle_refs(submodule, revs, *flags, for_each_ref_submodule);
1545                handle_refs(submodule, revs, *flags, head_ref_submodule);
1546        } else if (!strcmp(arg, "--branches")) {
1547                handle_refs(submodule, revs, *flags, for_each_branch_ref_submodule);
1548        } else if (!strcmp(arg, "--bisect")) {
1549                handle_refs(submodule, revs, *flags, for_each_bad_bisect_ref);
1550                handle_refs(submodule, revs, *flags ^ UNINTERESTING, for_each_good_bisect_ref);
1551                revs->bisect = 1;
1552        } else if (!strcmp(arg, "--tags")) {
1553                handle_refs(submodule, revs, *flags, for_each_tag_ref_submodule);
1554        } else if (!strcmp(arg, "--remotes")) {
1555                handle_refs(submodule, revs, *flags, for_each_remote_ref_submodule);
1556        } else if ((argcount = parse_long_opt("glob", argv, &optarg))) {
1557                struct all_refs_cb cb;
1558                init_all_refs_cb(&cb, revs, *flags);
1559                for_each_glob_ref(handle_one_ref, optarg, &cb);
1560                return argcount;
1561        } else if (!prefixcmp(arg, "--branches=")) {
1562                struct all_refs_cb cb;
1563                init_all_refs_cb(&cb, revs, *flags);
1564                for_each_glob_ref_in(handle_one_ref, arg + 11, "refs/heads/", &cb);
1565        } else if (!prefixcmp(arg, "--tags=")) {
1566                struct all_refs_cb cb;
1567                init_all_refs_cb(&cb, revs, *flags);
1568                for_each_glob_ref_in(handle_one_ref, arg + 7, "refs/tags/", &cb);
1569        } else if (!prefixcmp(arg, "--remotes=")) {
1570                struct all_refs_cb cb;
1571                init_all_refs_cb(&cb, revs, *flags);
1572                for_each_glob_ref_in(handle_one_ref, arg + 10, "refs/remotes/", &cb);
1573        } else if (!strcmp(arg, "--reflog")) {
1574                handle_reflog(revs, *flags);
1575        } else if (!strcmp(arg, "--not")) {
1576                *flags ^= UNINTERESTING;
1577        } else if (!strcmp(arg, "--no-walk")) {
1578                revs->no_walk = 1;
1579        } else if (!strcmp(arg, "--do-walk")) {
1580                revs->no_walk = 0;
1581        } else {
1582                return 0;
1583        }
1584
1585        return 1;
1586}
1587
1588/*
1589 * Parse revision information, filling in the "rev_info" structure,
1590 * and removing the used arguments from the argument list.
1591 *
1592 * Returns the number of arguments left that weren't recognized
1593 * (which are also moved to the head of the argument list)
1594 */
1595int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
1596{
1597        int i, flags, left, seen_dashdash, read_from_stdin, got_rev_arg = 0;
1598        struct cmdline_pathspec prune_data;
1599        const char *submodule = NULL;
1600
1601        memset(&prune_data, 0, sizeof(prune_data));
1602        if (opt)
1603                submodule = opt->submodule;
1604
1605        /* First, search for "--" */
1606        seen_dashdash = 0;
1607        for (i = 1; i < argc; i++) {
1608                const char *arg = argv[i];
1609                if (strcmp(arg, "--"))
1610                        continue;
1611                argv[i] = NULL;
1612                argc = i;
1613                if (argv[i + 1])
1614                        append_prune_data(&prune_data, argv + i + 1);
1615                seen_dashdash = 1;
1616                break;
1617        }
1618
1619        /* Second, deal with arguments and options */
1620        flags = 0;
1621        read_from_stdin = 0;
1622        for (left = i = 1; i < argc; i++) {
1623                const char *arg = argv[i];
1624                if (*arg == '-') {
1625                        int opts;
1626
1627                        opts = handle_revision_pseudo_opt(submodule,
1628                                                revs, argc - i, argv + i,
1629                                                &flags);
1630                        if (opts > 0) {
1631                                i += opts - 1;
1632                                continue;
1633                        }
1634
1635                        if (!strcmp(arg, "--stdin")) {
1636                                if (revs->disable_stdin) {
1637                                        argv[left++] = arg;
1638                                        continue;
1639                                }
1640                                if (read_from_stdin++)
1641                                        die("--stdin given twice?");
1642                                read_revisions_from_stdin(revs, &prune_data);
1643                                continue;
1644                        }
1645
1646                        opts = handle_revision_opt(revs, argc - i, argv + i, &left, argv);
1647                        if (opts > 0) {
1648                                i += opts - 1;
1649                                continue;
1650                        }
1651                        if (opts < 0)
1652                                exit(128);
1653                        continue;
1654                }
1655
1656                if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
1657                        int j;
1658                        if (seen_dashdash || *arg == '^')
1659                                die("bad revision '%s'", arg);
1660
1661                        /* If we didn't have a "--":
1662                         * (1) all filenames must exist;
1663                         * (2) all rev-args must not be interpretable
1664                         *     as a valid filename.
1665                         * but the latter we have checked in the main loop.
1666                         */
1667                        for (j = i; j < argc; j++)
1668                                verify_filename(revs->prefix, argv[j]);
1669
1670                        append_prune_data(&prune_data, argv + i);
1671                        break;
1672                }
1673                else
1674                        got_rev_arg = 1;
1675        }
1676
1677        if (prune_data.nr) {
1678                /*
1679                 * If we need to introduce the magic "a lone ':' means no
1680                 * pathspec whatsoever", here is the place to do so.
1681                 *
1682                 * if (prune_data.nr == 1 && !strcmp(prune_data[0], ":")) {
1683                 *      prune_data.nr = 0;
1684                 *      prune_data.alloc = 0;
1685                 *      free(prune_data.path);
1686                 *      prune_data.path = NULL;
1687                 * } else {
1688                 *      terminate prune_data.alloc with NULL and
1689                 *      call init_pathspec() to set revs->prune_data here.
1690                 * }
1691                 */
1692                ALLOC_GROW(prune_data.path, prune_data.nr+1, prune_data.alloc);
1693                prune_data.path[prune_data.nr++] = NULL;
1694                init_pathspec(&revs->prune_data,
1695                              get_pathspec(revs->prefix, prune_data.path));
1696        }
1697
1698        if (revs->def == NULL)
1699                revs->def = opt ? opt->def : NULL;
1700        if (opt && opt->tweak)
1701                opt->tweak(revs, opt);
1702        if (revs->show_merge)
1703                prepare_show_merge(revs);
1704        if (revs->def && !revs->pending.nr && !got_rev_arg) {
1705                unsigned char sha1[20];
1706                struct object *object;
1707                unsigned mode;
1708                if (get_sha1_with_mode(revs->def, sha1, &mode))
1709                        die("bad default revision '%s'", revs->def);
1710                object = get_reference(revs, revs->def, sha1, 0);
1711                add_pending_object_with_mode(revs, object, revs->def, mode);
1712        }
1713
1714        /* Did the user ask for any diff output? Run the diff! */
1715        if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
1716                revs->diff = 1;
1717
1718        /* Pickaxe, diff-filter and rename following need diffs */
1719        if (revs->diffopt.pickaxe ||
1720            revs->diffopt.filter ||
1721            DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1722                revs->diff = 1;
1723
1724        if (revs->topo_order)
1725                revs->limited = 1;
1726
1727        if (revs->prune_data.nr) {
1728                diff_tree_setup_paths(revs->prune_data.raw, &revs->pruning);
1729                /* Can't prune commits with rename following: the paths change.. */
1730                if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1731                        revs->prune = 1;
1732                if (!revs->full_diff)
1733                        diff_tree_setup_paths(revs->prune_data.raw, &revs->diffopt);
1734        }
1735        if (revs->combine_merges)
1736                revs->ignore_merges = 0;
1737        revs->diffopt.abbrev = revs->abbrev;
1738        if (diff_setup_done(&revs->diffopt) < 0)
1739                die("diff_setup_done failed");
1740
1741        compile_grep_patterns(&revs->grep_filter);
1742
1743        if (revs->reverse && revs->reflog_info)
1744                die("cannot combine --reverse with --walk-reflogs");
1745        if (revs->rewrite_parents && revs->children.name)
1746                die("cannot combine --parents and --children");
1747
1748        /*
1749         * Limitations on the graph functionality
1750         */
1751        if (revs->reverse && revs->graph)
1752                die("cannot combine --reverse with --graph");
1753
1754        if (revs->reflog_info && revs->graph)
1755                die("cannot combine --walk-reflogs with --graph");
1756
1757        return left;
1758}
1759
1760static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
1761{
1762        struct commit_list *l = xcalloc(1, sizeof(*l));
1763
1764        l->item = child;
1765        l->next = add_decoration(&revs->children, &parent->object, l);
1766}
1767
1768static int remove_duplicate_parents(struct commit *commit)
1769{
1770        struct commit_list **pp, *p;
1771        int surviving_parents;
1772
1773        /* Examine existing parents while marking ones we have seen... */
1774        pp = &commit->parents;
1775        while ((p = *pp) != NULL) {
1776                struct commit *parent = p->item;
1777                if (parent->object.flags & TMP_MARK) {
1778                        *pp = p->next;
1779                        continue;
1780                }
1781                parent->object.flags |= TMP_MARK;
1782                pp = &p->next;
1783        }
1784        /* count them while clearing the temporary mark */
1785        surviving_parents = 0;
1786        for (p = commit->parents; p; p = p->next) {
1787                p->item->object.flags &= ~TMP_MARK;
1788                surviving_parents++;
1789        }
1790        return surviving_parents;
1791}
1792
1793struct merge_simplify_state {
1794        struct commit *simplified;
1795};
1796
1797static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
1798{
1799        struct merge_simplify_state *st;
1800
1801        st = lookup_decoration(&revs->merge_simplification, &commit->object);
1802        if (!st) {
1803                st = xcalloc(1, sizeof(*st));
1804                add_decoration(&revs->merge_simplification, &commit->object, st);
1805        }
1806        return st;
1807}
1808
1809static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
1810{
1811        struct commit_list *p;
1812        struct merge_simplify_state *st, *pst;
1813        int cnt;
1814
1815        st = locate_simplify_state(revs, commit);
1816
1817        /*
1818         * Have we handled this one?
1819         */
1820        if (st->simplified)
1821                return tail;
1822
1823        /*
1824         * An UNINTERESTING commit simplifies to itself, so does a
1825         * root commit.  We do not rewrite parents of such commit
1826         * anyway.
1827         */
1828        if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
1829                st->simplified = commit;
1830                return tail;
1831        }
1832
1833        /*
1834         * Do we know what commit all of our parents should be rewritten to?
1835         * Otherwise we are not ready to rewrite this one yet.
1836         */
1837        for (cnt = 0, p = commit->parents; p; p = p->next) {
1838                pst = locate_simplify_state(revs, p->item);
1839                if (!pst->simplified) {
1840                        tail = &commit_list_insert(p->item, tail)->next;
1841                        cnt++;
1842                }
1843        }
1844        if (cnt) {
1845                tail = &commit_list_insert(commit, tail)->next;
1846                return tail;
1847        }
1848
1849        /*
1850         * Rewrite our list of parents.
1851         */
1852        for (p = commit->parents; p; p = p->next) {
1853                pst = locate_simplify_state(revs, p->item);
1854                p->item = pst->simplified;
1855        }
1856        cnt = remove_duplicate_parents(commit);
1857
1858        /*
1859         * It is possible that we are a merge and one side branch
1860         * does not have any commit that touches the given paths;
1861         * in such a case, the immediate parents will be rewritten
1862         * to different commits.
1863         *
1864         *      o----X          X: the commit we are looking at;
1865         *     /    /           o: a commit that touches the paths;
1866         * ---o----'
1867         *
1868         * Further reduce the parents by removing redundant parents.
1869         */
1870        if (1 < cnt) {
1871                struct commit_list *h = reduce_heads(commit->parents);
1872                cnt = commit_list_count(h);
1873                free_commit_list(commit->parents);
1874                commit->parents = h;
1875        }
1876
1877        /*
1878         * A commit simplifies to itself if it is a root, if it is
1879         * UNINTERESTING, if it touches the given paths, or if it is a
1880         * merge and its parents simplifies to more than one commits
1881         * (the first two cases are already handled at the beginning of
1882         * this function).
1883         *
1884         * Otherwise, it simplifies to what its sole parent simplifies to.
1885         */
1886        if (!cnt ||
1887            (commit->object.flags & UNINTERESTING) ||
1888            !(commit->object.flags & TREESAME) ||
1889            (1 < cnt))
1890                st->simplified = commit;
1891        else {
1892                pst = locate_simplify_state(revs, commit->parents->item);
1893                st->simplified = pst->simplified;
1894        }
1895        return tail;
1896}
1897
1898static void simplify_merges(struct rev_info *revs)
1899{
1900        struct commit_list *list;
1901        struct commit_list *yet_to_do, **tail;
1902
1903        if (!revs->topo_order)
1904                sort_in_topological_order(&revs->commits, revs->lifo);
1905        if (!revs->prune)
1906                return;
1907
1908        /* feed the list reversed */
1909        yet_to_do = NULL;
1910        for (list = revs->commits; list; list = list->next)
1911                commit_list_insert(list->item, &yet_to_do);
1912        while (yet_to_do) {
1913                list = yet_to_do;
1914                yet_to_do = NULL;
1915                tail = &yet_to_do;
1916                while (list) {
1917                        struct commit *commit = list->item;
1918                        struct commit_list *next = list->next;
1919                        free(list);
1920                        list = next;
1921                        tail = simplify_one(revs, commit, tail);
1922                }
1923        }
1924
1925        /* clean up the result, removing the simplified ones */
1926        list = revs->commits;
1927        revs->commits = NULL;
1928        tail = &revs->commits;
1929        while (list) {
1930                struct commit *commit = list->item;
1931                struct commit_list *next = list->next;
1932                struct merge_simplify_state *st;
1933                free(list);
1934                list = next;
1935                st = locate_simplify_state(revs, commit);
1936                if (st->simplified == commit)
1937                        tail = &commit_list_insert(commit, tail)->next;
1938        }
1939}
1940
1941static void set_children(struct rev_info *revs)
1942{
1943        struct commit_list *l;
1944        for (l = revs->commits; l; l = l->next) {
1945                struct commit *commit = l->item;
1946                struct commit_list *p;
1947
1948                for (p = commit->parents; p; p = p->next)
1949                        add_child(revs, p->item, commit);
1950        }
1951}
1952
1953int prepare_revision_walk(struct rev_info *revs)
1954{
1955        int nr = revs->pending.nr;
1956        struct object_array_entry *e, *list;
1957
1958        e = list = revs->pending.objects;
1959        revs->pending.nr = 0;
1960        revs->pending.alloc = 0;
1961        revs->pending.objects = NULL;
1962        while (--nr >= 0) {
1963                struct commit *commit = handle_commit(revs, e->item, e->name);
1964                if (commit) {
1965                        if (!(commit->object.flags & SEEN)) {
1966                                commit->object.flags |= SEEN;
1967                                commit_list_insert_by_date(commit, &revs->commits);
1968                        }
1969                }
1970                e++;
1971        }
1972        free(list);
1973
1974        if (revs->no_walk)
1975                return 0;
1976        if (revs->limited)
1977                if (limit_list(revs) < 0)
1978                        return -1;
1979        if (revs->topo_order)
1980                sort_in_topological_order(&revs->commits, revs->lifo);
1981        if (revs->simplify_merges)
1982                simplify_merges(revs);
1983        if (revs->children.name)
1984                set_children(revs);
1985        return 0;
1986}
1987
1988enum rewrite_result {
1989        rewrite_one_ok,
1990        rewrite_one_noparents,
1991        rewrite_one_error
1992};
1993
1994static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
1995{
1996        struct commit_list *cache = NULL;
1997
1998        for (;;) {
1999                struct commit *p = *pp;
2000                if (!revs->limited)
2001                        if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0)
2002                                return rewrite_one_error;
2003                if (p->parents && p->parents->next)
2004                        return rewrite_one_ok;
2005                if (p->object.flags & UNINTERESTING)
2006                        return rewrite_one_ok;
2007                if (!(p->object.flags & TREESAME))
2008                        return rewrite_one_ok;
2009                if (!p->parents)
2010                        return rewrite_one_noparents;
2011                *pp = p->parents->item;
2012        }
2013}
2014
2015static int rewrite_parents(struct rev_info *revs, struct commit *commit)
2016{
2017        struct commit_list **pp = &commit->parents;
2018        while (*pp) {
2019                struct commit_list *parent = *pp;
2020                switch (rewrite_one(revs, &parent->item)) {
2021                case rewrite_one_ok:
2022                        break;
2023                case rewrite_one_noparents:
2024                        *pp = parent->next;
2025                        continue;
2026                case rewrite_one_error:
2027                        return -1;
2028                }
2029                pp = &parent->next;
2030        }
2031        remove_duplicate_parents(commit);
2032        return 0;
2033}
2034
2035static int commit_match(struct commit *commit, struct rev_info *opt)
2036{
2037        if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
2038                return 1;
2039        return grep_buffer(&opt->grep_filter,
2040                           NULL, /* we say nothing, not even filename */
2041                           commit->buffer, strlen(commit->buffer));
2042}
2043
2044static inline int want_ancestry(struct rev_info *revs)
2045{
2046        return (revs->rewrite_parents || revs->children.name);
2047}
2048
2049enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
2050{
2051        if (commit->object.flags & SHOWN)
2052                return commit_ignore;
2053        if (revs->unpacked && has_sha1_pack(commit->object.sha1))
2054                return commit_ignore;
2055        if (revs->show_all)
2056                return commit_show;
2057        if (commit->object.flags & UNINTERESTING)
2058                return commit_ignore;
2059        if (revs->min_age != -1 && (commit->date > revs->min_age))
2060                return commit_ignore;
2061        if (revs->min_parents || (revs->max_parents >= 0)) {
2062                int n = 0;
2063                struct commit_list *p;
2064                for (p = commit->parents; p; p = p->next)
2065                        n++;
2066                if ((n < revs->min_parents) ||
2067                    ((revs->max_parents >= 0) && (n > revs->max_parents)))
2068                        return commit_ignore;
2069        }
2070        if (!commit_match(commit, revs))
2071                return commit_ignore;
2072        if (revs->prune && revs->dense) {
2073                /* Commit without changes? */
2074                if (commit->object.flags & TREESAME) {
2075                        /* drop merges unless we want parenthood */
2076                        if (!want_ancestry(revs))
2077                                return commit_ignore;
2078                        /* non-merge - always ignore it */
2079                        if (!commit->parents || !commit->parents->next)
2080                                return commit_ignore;
2081                }
2082        }
2083        return commit_show;
2084}
2085
2086enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
2087{
2088        enum commit_action action = get_commit_action(revs, commit);
2089
2090        if (action == commit_show &&
2091            !revs->show_all &&
2092            revs->prune && revs->dense && want_ancestry(revs)) {
2093                if (rewrite_parents(revs, commit) < 0)
2094                        return commit_error;
2095        }
2096        return action;
2097}
2098
2099static struct commit *get_revision_1(struct rev_info *revs)
2100{
2101        if (!revs->commits)
2102                return NULL;
2103
2104        do {
2105                struct commit_list *entry = revs->commits;
2106                struct commit *commit = entry->item;
2107
2108                revs->commits = entry->next;
2109                free(entry);
2110
2111                if (revs->reflog_info) {
2112                        fake_reflog_parent(revs->reflog_info, commit);
2113                        commit->object.flags &= ~(ADDED | SEEN | SHOWN);
2114                }
2115
2116                /*
2117                 * If we haven't done the list limiting, we need to look at
2118                 * the parents here. We also need to do the date-based limiting
2119                 * that we'd otherwise have done in limit_list().
2120                 */
2121                if (!revs->limited) {
2122                        if (revs->max_age != -1 &&
2123                            (commit->date < revs->max_age))
2124                                continue;
2125                        if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0)
2126                                die("Failed to traverse parents of commit %s",
2127                                    sha1_to_hex(commit->object.sha1));
2128                }
2129
2130                switch (simplify_commit(revs, commit)) {
2131                case commit_ignore:
2132                        continue;
2133                case commit_error:
2134                        die("Failed to simplify parents of commit %s",
2135                            sha1_to_hex(commit->object.sha1));
2136                default:
2137                        return commit;
2138                }
2139        } while (revs->commits);
2140        return NULL;
2141}
2142
2143static void gc_boundary(struct object_array *array)
2144{
2145        unsigned nr = array->nr;
2146        unsigned alloc = array->alloc;
2147        struct object_array_entry *objects = array->objects;
2148
2149        if (alloc <= nr) {
2150                unsigned i, j;
2151                for (i = j = 0; i < nr; i++) {
2152                        if (objects[i].item->flags & SHOWN)
2153                                continue;
2154                        if (i != j)
2155                                objects[j] = objects[i];
2156                        j++;
2157                }
2158                for (i = j; i < nr; i++)
2159                        objects[i].item = NULL;
2160                array->nr = j;
2161        }
2162}
2163
2164static void create_boundary_commit_list(struct rev_info *revs)
2165{
2166        unsigned i;
2167        struct commit *c;
2168        struct object_array *array = &revs->boundary_commits;
2169        struct object_array_entry *objects = array->objects;
2170
2171        /*
2172         * If revs->commits is non-NULL at this point, an error occurred in
2173         * get_revision_1().  Ignore the error and continue printing the
2174         * boundary commits anyway.  (This is what the code has always
2175         * done.)
2176         */
2177        if (revs->commits) {
2178                free_commit_list(revs->commits);
2179                revs->commits = NULL;
2180        }
2181
2182        /*
2183         * Put all of the actual boundary commits from revs->boundary_commits
2184         * into revs->commits
2185         */
2186        for (i = 0; i < array->nr; i++) {
2187                c = (struct commit *)(objects[i].item);
2188                if (!c)
2189                        continue;
2190                if (!(c->object.flags & CHILD_SHOWN))
2191                        continue;
2192                if (c->object.flags & (SHOWN | BOUNDARY))
2193                        continue;
2194                c->object.flags |= BOUNDARY;
2195                commit_list_insert(c, &revs->commits);
2196        }
2197
2198        /*
2199         * If revs->topo_order is set, sort the boundary commits
2200         * in topological order
2201         */
2202        sort_in_topological_order(&revs->commits, revs->lifo);
2203}
2204
2205static struct commit *get_revision_internal(struct rev_info *revs)
2206{
2207        struct commit *c = NULL;
2208        struct commit_list *l;
2209
2210        if (revs->boundary == 2) {
2211                /*
2212                 * All of the normal commits have already been returned,
2213                 * and we are now returning boundary commits.
2214                 * create_boundary_commit_list() has populated
2215                 * revs->commits with the remaining commits to return.
2216                 */
2217                c = pop_commit(&revs->commits);
2218                if (c)
2219                        c->object.flags |= SHOWN;
2220                return c;
2221        }
2222
2223        /*
2224         * Now pick up what they want to give us
2225         */
2226        c = get_revision_1(revs);
2227        if (c) {
2228                while (0 < revs->skip_count) {
2229                        revs->skip_count--;
2230                        c = get_revision_1(revs);
2231                        if (!c)
2232                                break;
2233                }
2234        }
2235
2236        /*
2237         * Check the max_count.
2238         */
2239        switch (revs->max_count) {
2240        case -1:
2241                break;
2242        case 0:
2243                c = NULL;
2244                break;
2245        default:
2246                revs->max_count--;
2247        }
2248
2249        if (c)
2250                c->object.flags |= SHOWN;
2251
2252        if (!revs->boundary) {
2253                return c;
2254        }
2255
2256        if (!c) {
2257                /*
2258                 * get_revision_1() runs out the commits, and
2259                 * we are done computing the boundaries.
2260                 * switch to boundary commits output mode.
2261                 */
2262                revs->boundary = 2;
2263
2264                /*
2265                 * Update revs->commits to contain the list of
2266                 * boundary commits.
2267                 */
2268                create_boundary_commit_list(revs);
2269
2270                return get_revision_internal(revs);
2271        }
2272
2273        /*
2274         * boundary commits are the commits that are parents of the
2275         * ones we got from get_revision_1() but they themselves are
2276         * not returned from get_revision_1().  Before returning
2277         * 'c', we need to mark its parents that they could be boundaries.
2278         */
2279
2280        for (l = c->parents; l; l = l->next) {
2281                struct object *p;
2282                p = &(l->item->object);
2283                if (p->flags & (CHILD_SHOWN | SHOWN))
2284                        continue;
2285                p->flags |= CHILD_SHOWN;
2286                gc_boundary(&revs->boundary_commits);
2287                add_object_array(p, NULL, &revs->boundary_commits);
2288        }
2289
2290        return c;
2291}
2292
2293struct commit *get_revision(struct rev_info *revs)
2294{
2295        struct commit *c;
2296        struct commit_list *reversed;
2297
2298        if (revs->reverse) {
2299                reversed = NULL;
2300                while ((c = get_revision_internal(revs))) {
2301                        commit_list_insert(c, &reversed);
2302                }
2303                revs->commits = reversed;
2304                revs->reverse = 0;
2305                revs->reverse_output_stage = 1;
2306        }
2307
2308        if (revs->reverse_output_stage)
2309                return pop_commit(&revs->commits);
2310
2311        c = get_revision_internal(revs);
2312        if (c && revs->graph)
2313                graph_update(revs->graph, c);
2314        return c;
2315}
2316
2317char *get_revision_mark(const struct rev_info *revs, const struct commit *commit)
2318{
2319        if (commit->object.flags & BOUNDARY)
2320                return "-";
2321        else if (commit->object.flags & UNINTERESTING)
2322                return "^";
2323        else if (commit->object.flags & PATCHSAME)
2324                return "=";
2325        else if (!revs || revs->left_right) {
2326                if (commit->object.flags & SYMMETRIC_LEFT)
2327                        return "<";
2328                else
2329                        return ">";
2330        } else if (revs->graph)
2331                return "*";
2332        else if (revs->cherry_mark)
2333                return "+";
2334        return "";
2335}
2336
2337void put_revision_mark(const struct rev_info *revs, const struct commit *commit)
2338{
2339        char *mark = get_revision_mark(revs, commit);
2340        if (!strlen(mark))
2341                return;
2342        fputs(mark, stdout);
2343        putchar(' ');
2344}