revision.con commit specifying ranges: we did not mean to make ".." an empty set (003c84f)
   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
  43static int show_path_component_truncated(FILE *out, const char *name, int len)
  44{
  45        int cnt;
  46        for (cnt = 0; cnt < len; cnt++) {
  47                int ch = name[cnt];
  48                if (!ch || ch == '\n')
  49                        return -1;
  50                fputc(ch, out);
  51        }
  52        return len;
  53}
  54
  55static int show_path_truncated(FILE *out, const struct name_path *path)
  56{
  57        int emitted, ours;
  58
  59        if (!path)
  60                return 0;
  61        emitted = show_path_truncated(out, path->up);
  62        if (emitted < 0)
  63                return emitted;
  64        if (emitted)
  65                fputc('/', out);
  66        ours = show_path_component_truncated(out, path->elem, path->elem_len);
  67        if (ours < 0)
  68                return ours;
  69        return ours || emitted;
  70}
  71
  72void show_object_with_name(FILE *out, struct object *obj, const struct name_path *path, const char *component)
  73{
  74        struct name_path leaf;
  75        leaf.up = (struct name_path *)path;
  76        leaf.elem = component;
  77        leaf.elem_len = strlen(component);
  78
  79        fprintf(out, "%s ", sha1_to_hex(obj->sha1));
  80        show_path_truncated(out, &leaf);
  81        fputc('\n', out);
  82}
  83
  84void add_object(struct object *obj,
  85                struct object_array *p,
  86                struct name_path *path,
  87                const char *name)
  88{
  89        add_object_array(obj, path_name(path, name), p);
  90}
  91
  92static void mark_blob_uninteresting(struct blob *blob)
  93{
  94        if (!blob)
  95                return;
  96        if (blob->object.flags & UNINTERESTING)
  97                return;
  98        blob->object.flags |= UNINTERESTING;
  99}
 100
 101void mark_tree_uninteresting(struct tree *tree)
 102{
 103        struct tree_desc desc;
 104        struct name_entry entry;
 105        struct object *obj = &tree->object;
 106
 107        if (!tree)
 108                return;
 109        if (obj->flags & UNINTERESTING)
 110                return;
 111        obj->flags |= UNINTERESTING;
 112        if (!has_sha1_file(obj->sha1))
 113                return;
 114        if (parse_tree(tree) < 0)
 115                die("bad tree %s", sha1_to_hex(obj->sha1));
 116
 117        init_tree_desc(&desc, tree->buffer, tree->size);
 118        while (tree_entry(&desc, &entry)) {
 119                switch (object_type(entry.mode)) {
 120                case OBJ_TREE:
 121                        mark_tree_uninteresting(lookup_tree(entry.sha1));
 122                        break;
 123                case OBJ_BLOB:
 124                        mark_blob_uninteresting(lookup_blob(entry.sha1));
 125                        break;
 126                default:
 127                        /* Subproject commit - not in this repository */
 128                        break;
 129                }
 130        }
 131
 132        /*
 133         * We don't care about the tree any more
 134         * after it has been marked uninteresting.
 135         */
 136        free(tree->buffer);
 137        tree->buffer = NULL;
 138}
 139
 140void mark_parents_uninteresting(struct commit *commit)
 141{
 142        struct commit_list *parents = NULL, *l;
 143
 144        for (l = commit->parents; l; l = l->next)
 145                commit_list_insert(l->item, &parents);
 146
 147        while (parents) {
 148                struct commit *commit = parents->item;
 149                l = parents;
 150                parents = parents->next;
 151                free(l);
 152
 153                while (commit) {
 154                        /*
 155                         * A missing commit is ok iff its parent is marked
 156                         * uninteresting.
 157                         *
 158                         * We just mark such a thing parsed, so that when
 159                         * it is popped next time around, we won't be trying
 160                         * to parse it and get an error.
 161                         */
 162                        if (!has_sha1_file(commit->object.sha1))
 163                                commit->object.parsed = 1;
 164
 165                        if (commit->object.flags & UNINTERESTING)
 166                                break;
 167
 168                        commit->object.flags |= UNINTERESTING;
 169
 170                        /*
 171                         * Normally we haven't parsed the parent
 172                         * yet, so we won't have a parent of a parent
 173                         * here. However, it may turn out that we've
 174                         * reached this commit some other way (where it
 175                         * wasn't uninteresting), in which case we need
 176                         * to mark its parents recursively too..
 177                         */
 178                        if (!commit->parents)
 179                                break;
 180
 181                        for (l = commit->parents->next; l; l = l->next)
 182                                commit_list_insert(l->item, &parents);
 183                        commit = commit->parents->item;
 184                }
 185        }
 186}
 187
 188static void add_pending_object_with_mode(struct rev_info *revs, struct object *obj, const char *name, unsigned mode)
 189{
 190        if (!obj)
 191                return;
 192        if (revs->no_walk && (obj->flags & UNINTERESTING))
 193                revs->no_walk = 0;
 194        if (revs->reflog_info && obj->type == OBJ_COMMIT) {
 195                struct strbuf buf = STRBUF_INIT;
 196                int len = interpret_branch_name(name, &buf);
 197                int st;
 198
 199                if (0 < len && name[len] && buf.len)
 200                        strbuf_addstr(&buf, name + len);
 201                st = add_reflog_for_walk(revs->reflog_info,
 202                                         (struct commit *)obj,
 203                                         buf.buf[0] ? buf.buf: name);
 204                strbuf_release(&buf);
 205                if (st)
 206                        return;
 207        }
 208        add_object_array_with_mode(obj, name, &revs->pending, mode);
 209}
 210
 211void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
 212{
 213        add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
 214}
 215
 216void add_head_to_pending(struct rev_info *revs)
 217{
 218        unsigned char sha1[20];
 219        struct object *obj;
 220        if (get_sha1("HEAD", sha1))
 221                return;
 222        obj = parse_object(sha1);
 223        if (!obj)
 224                return;
 225        add_pending_object(revs, obj, "HEAD");
 226}
 227
 228static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
 229{
 230        struct object *object;
 231
 232        object = parse_object(sha1);
 233        if (!object) {
 234                if (revs->ignore_missing)
 235                        return object;
 236                die("bad object %s", name);
 237        }
 238        object->flags |= flags;
 239        return object;
 240}
 241
 242void add_pending_sha1(struct rev_info *revs, const char *name,
 243                      const unsigned char *sha1, unsigned int flags)
 244{
 245        struct object *object = get_reference(revs, name, sha1, flags);
 246        add_pending_object(revs, object, name);
 247}
 248
 249static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
 250{
 251        unsigned long flags = object->flags;
 252
 253        /*
 254         * Tag object? Look what it points to..
 255         */
 256        while (object->type == OBJ_TAG) {
 257                struct tag *tag = (struct tag *) object;
 258                if (revs->tag_objects && !(flags & UNINTERESTING))
 259                        add_pending_object(revs, object, tag->tag);
 260                if (!tag->tagged)
 261                        die("bad tag");
 262                object = parse_object(tag->tagged->sha1);
 263                if (!object) {
 264                        if (flags & UNINTERESTING)
 265                                return NULL;
 266                        die("bad object %s", sha1_to_hex(tag->tagged->sha1));
 267                }
 268        }
 269
 270        /*
 271         * Commit object? Just return it, we'll do all the complex
 272         * reachability crud.
 273         */
 274        if (object->type == OBJ_COMMIT) {
 275                struct commit *commit = (struct commit *)object;
 276                if (parse_commit(commit) < 0)
 277                        die("unable to parse commit %s", name);
 278                if (flags & UNINTERESTING) {
 279                        commit->object.flags |= UNINTERESTING;
 280                        mark_parents_uninteresting(commit);
 281                        revs->limited = 1;
 282                }
 283                if (revs->show_source && !commit->util)
 284                        commit->util = (void *) name;
 285                return commit;
 286        }
 287
 288        /*
 289         * Tree object? Either mark it uninteresting, or add it
 290         * to the list of objects to look at later..
 291         */
 292        if (object->type == OBJ_TREE) {
 293                struct tree *tree = (struct tree *)object;
 294                if (!revs->tree_objects)
 295                        return NULL;
 296                if (flags & UNINTERESTING) {
 297                        mark_tree_uninteresting(tree);
 298                        return NULL;
 299                }
 300                add_pending_object(revs, object, "");
 301                return NULL;
 302        }
 303
 304        /*
 305         * Blob object? You know the drill by now..
 306         */
 307        if (object->type == OBJ_BLOB) {
 308                struct blob *blob = (struct blob *)object;
 309                if (!revs->blob_objects)
 310                        return NULL;
 311                if (flags & UNINTERESTING) {
 312                        mark_blob_uninteresting(blob);
 313                        return NULL;
 314                }
 315                add_pending_object(revs, object, "");
 316                return NULL;
 317        }
 318        die("%s is unknown object", name);
 319}
 320
 321static int everybody_uninteresting(struct commit_list *orig)
 322{
 323        struct commit_list *list = orig;
 324        while (list) {
 325                struct commit *commit = list->item;
 326                list = list->next;
 327                if (commit->object.flags & UNINTERESTING)
 328                        continue;
 329                return 0;
 330        }
 331        return 1;
 332}
 333
 334/*
 335 * The goal is to get REV_TREE_NEW as the result only if the
 336 * diff consists of all '+' (and no other changes), REV_TREE_OLD
 337 * if the whole diff is removal of old data, and otherwise
 338 * REV_TREE_DIFFERENT (of course if the trees are the same we
 339 * want REV_TREE_SAME).
 340 * That means that once we get to REV_TREE_DIFFERENT, we do not
 341 * have to look any further.
 342 */
 343static int tree_difference = REV_TREE_SAME;
 344
 345static void file_add_remove(struct diff_options *options,
 346                    int addremove, unsigned mode,
 347                    const unsigned char *sha1,
 348                    const char *fullpath, unsigned dirty_submodule)
 349{
 350        int diff = addremove == '+' ? REV_TREE_NEW : REV_TREE_OLD;
 351
 352        tree_difference |= diff;
 353        if (tree_difference == REV_TREE_DIFFERENT)
 354                DIFF_OPT_SET(options, HAS_CHANGES);
 355}
 356
 357static void file_change(struct diff_options *options,
 358                 unsigned old_mode, unsigned new_mode,
 359                 const unsigned char *old_sha1,
 360                 const unsigned char *new_sha1,
 361                 const char *fullpath,
 362                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
 363{
 364        tree_difference = REV_TREE_DIFFERENT;
 365        DIFF_OPT_SET(options, HAS_CHANGES);
 366}
 367
 368static int rev_compare_tree(struct rev_info *revs, struct commit *parent, struct commit *commit)
 369{
 370        struct tree *t1 = parent->tree;
 371        struct tree *t2 = commit->tree;
 372
 373        if (!t1)
 374                return REV_TREE_NEW;
 375        if (!t2)
 376                return REV_TREE_OLD;
 377
 378        if (revs->simplify_by_decoration) {
 379                /*
 380                 * If we are simplifying by decoration, then the commit
 381                 * is worth showing if it has a tag pointing at it.
 382                 */
 383                if (lookup_decoration(&name_decoration, &commit->object))
 384                        return REV_TREE_DIFFERENT;
 385                /*
 386                 * A commit that is not pointed by a tag is uninteresting
 387                 * if we are not limited by path.  This means that you will
 388                 * see the usual "commits that touch the paths" plus any
 389                 * tagged commit by specifying both --simplify-by-decoration
 390                 * and pathspec.
 391                 */
 392                if (!revs->prune_data.nr)
 393                        return REV_TREE_SAME;
 394        }
 395
 396        tree_difference = REV_TREE_SAME;
 397        DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 398        if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
 399                           &revs->pruning) < 0)
 400                return REV_TREE_DIFFERENT;
 401        return tree_difference;
 402}
 403
 404static int rev_same_tree_as_empty(struct rev_info *revs, struct commit *commit)
 405{
 406        int retval;
 407        void *tree;
 408        unsigned long size;
 409        struct tree_desc empty, real;
 410        struct tree *t1 = commit->tree;
 411
 412        if (!t1)
 413                return 0;
 414
 415        tree = read_object_with_reference(t1->object.sha1, tree_type, &size, NULL);
 416        if (!tree)
 417                return 0;
 418        init_tree_desc(&real, tree, size);
 419        init_tree_desc(&empty, "", 0);
 420
 421        tree_difference = REV_TREE_SAME;
 422        DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 423        retval = diff_tree(&empty, &real, "", &revs->pruning);
 424        free(tree);
 425
 426        return retval >= 0 && (tree_difference == REV_TREE_SAME);
 427}
 428
 429static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 430{
 431        struct commit_list **pp, *parent;
 432        int tree_changed = 0, tree_same = 0, nth_parent = 0;
 433
 434        /*
 435         * If we don't do pruning, everything is interesting
 436         */
 437        if (!revs->prune)
 438                return;
 439
 440        if (!commit->tree)
 441                return;
 442
 443        if (!commit->parents) {
 444                if (rev_same_tree_as_empty(revs, commit))
 445                        commit->object.flags |= TREESAME;
 446                return;
 447        }
 448
 449        /*
 450         * Normal non-merge commit? If we don't want to make the
 451         * history dense, we consider it always to be a change..
 452         */
 453        if (!revs->dense && !commit->parents->next)
 454                return;
 455
 456        pp = &commit->parents;
 457        while ((parent = *pp) != NULL) {
 458                struct commit *p = parent->item;
 459
 460                /*
 461                 * Do not compare with later parents when we care only about
 462                 * the first parent chain, in order to avoid derailing the
 463                 * traversal to follow a side branch that brought everything
 464                 * in the path we are limited to by the pathspec.
 465                 */
 466                if (revs->first_parent_only && nth_parent++)
 467                        break;
 468                if (parse_commit(p) < 0)
 469                        die("cannot simplify commit %s (because of %s)",
 470                            sha1_to_hex(commit->object.sha1),
 471                            sha1_to_hex(p->object.sha1));
 472                switch (rev_compare_tree(revs, p, commit)) {
 473                case REV_TREE_SAME:
 474                        tree_same = 1;
 475                        if (!revs->simplify_history || (p->object.flags & UNINTERESTING)) {
 476                                /* Even if a merge with an uninteresting
 477                                 * side branch brought the entire change
 478                                 * we are interested in, we do not want
 479                                 * to lose the other branches of this
 480                                 * merge, so we just keep going.
 481                                 */
 482                                pp = &parent->next;
 483                                continue;
 484                        }
 485                        parent->next = NULL;
 486                        commit->parents = parent;
 487                        commit->object.flags |= TREESAME;
 488                        return;
 489
 490                case REV_TREE_NEW:
 491                        if (revs->remove_empty_trees &&
 492                            rev_same_tree_as_empty(revs, p)) {
 493                                /* We are adding all the specified
 494                                 * paths from this parent, so the
 495                                 * history beyond this parent is not
 496                                 * interesting.  Remove its parents
 497                                 * (they are grandparents for us).
 498                                 * IOW, we pretend this parent is a
 499                                 * "root" commit.
 500                                 */
 501                                if (parse_commit(p) < 0)
 502                                        die("cannot simplify commit %s (invalid %s)",
 503                                            sha1_to_hex(commit->object.sha1),
 504                                            sha1_to_hex(p->object.sha1));
 505                                p->parents = NULL;
 506                        }
 507                /* fallthrough */
 508                case REV_TREE_OLD:
 509                case REV_TREE_DIFFERENT:
 510                        tree_changed = 1;
 511                        pp = &parent->next;
 512                        continue;
 513                }
 514                die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
 515        }
 516        if (tree_changed && !tree_same)
 517                return;
 518        commit->object.flags |= TREESAME;
 519}
 520
 521static void commit_list_insert_by_date_cached(struct commit *p, struct commit_list **head,
 522                    struct commit_list *cached_base, struct commit_list **cache)
 523{
 524        struct commit_list *new_entry;
 525
 526        if (cached_base && p->date < cached_base->item->date)
 527                new_entry = commit_list_insert_by_date(p, &cached_base->next);
 528        else
 529                new_entry = commit_list_insert_by_date(p, head);
 530
 531        if (cache && (!*cache || p->date < (*cache)->item->date))
 532                *cache = new_entry;
 533}
 534
 535static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
 536                    struct commit_list **list, struct commit_list **cache_ptr)
 537{
 538        struct commit_list *parent = commit->parents;
 539        unsigned left_flag;
 540        struct commit_list *cached_base = cache_ptr ? *cache_ptr : NULL;
 541
 542        if (commit->object.flags & ADDED)
 543                return 0;
 544        commit->object.flags |= ADDED;
 545
 546        /*
 547         * If the commit is uninteresting, don't try to
 548         * prune parents - we want the maximal uninteresting
 549         * set.
 550         *
 551         * Normally we haven't parsed the parent
 552         * yet, so we won't have a parent of a parent
 553         * here. However, it may turn out that we've
 554         * reached this commit some other way (where it
 555         * wasn't uninteresting), in which case we need
 556         * to mark its parents recursively too..
 557         */
 558        if (commit->object.flags & UNINTERESTING) {
 559                while (parent) {
 560                        struct commit *p = parent->item;
 561                        parent = parent->next;
 562                        if (p)
 563                                p->object.flags |= UNINTERESTING;
 564                        if (parse_commit(p) < 0)
 565                                continue;
 566                        if (p->parents)
 567                                mark_parents_uninteresting(p);
 568                        if (p->object.flags & SEEN)
 569                                continue;
 570                        p->object.flags |= SEEN;
 571                        commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
 572                }
 573                return 0;
 574        }
 575
 576        /*
 577         * Ok, the commit wasn't uninteresting. Try to
 578         * simplify the commit history and find the parent
 579         * that has no differences in the path set if one exists.
 580         */
 581        try_to_simplify_commit(revs, commit);
 582
 583        if (revs->no_walk)
 584                return 0;
 585
 586        left_flag = (commit->object.flags & SYMMETRIC_LEFT);
 587
 588        for (parent = commit->parents; parent; parent = parent->next) {
 589                struct commit *p = parent->item;
 590
 591                if (parse_commit(p) < 0)
 592                        return -1;
 593                if (revs->show_source && !p->util)
 594                        p->util = commit->util;
 595                p->object.flags |= left_flag;
 596                if (!(p->object.flags & SEEN)) {
 597                        p->object.flags |= SEEN;
 598                        commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
 599                }
 600                if (revs->first_parent_only)
 601                        break;
 602        }
 603        return 0;
 604}
 605
 606static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
 607{
 608        struct commit_list *p;
 609        int left_count = 0, right_count = 0;
 610        int left_first;
 611        struct patch_ids ids;
 612        unsigned cherry_flag;
 613
 614        /* First count the commits on the left and on the right */
 615        for (p = list; p; p = p->next) {
 616                struct commit *commit = p->item;
 617                unsigned flags = commit->object.flags;
 618                if (flags & BOUNDARY)
 619                        ;
 620                else if (flags & SYMMETRIC_LEFT)
 621                        left_count++;
 622                else
 623                        right_count++;
 624        }
 625
 626        if (!left_count || !right_count)
 627                return;
 628
 629        left_first = left_count < right_count;
 630        init_patch_ids(&ids);
 631        ids.diffopts.pathspec = revs->diffopt.pathspec;
 632
 633        /* Compute patch-ids for one side */
 634        for (p = list; p; p = p->next) {
 635                struct commit *commit = p->item;
 636                unsigned flags = commit->object.flags;
 637
 638                if (flags & BOUNDARY)
 639                        continue;
 640                /*
 641                 * If we have fewer left, left_first is set and we omit
 642                 * commits on the right branch in this loop.  If we have
 643                 * fewer right, we skip the left ones.
 644                 */
 645                if (left_first != !!(flags & SYMMETRIC_LEFT))
 646                        continue;
 647                commit->util = add_commit_patch_id(commit, &ids);
 648        }
 649
 650        /* either cherry_mark or cherry_pick are true */
 651        cherry_flag = revs->cherry_mark ? PATCHSAME : SHOWN;
 652
 653        /* Check the other side */
 654        for (p = list; p; p = p->next) {
 655                struct commit *commit = p->item;
 656                struct patch_id *id;
 657                unsigned flags = commit->object.flags;
 658
 659                if (flags & BOUNDARY)
 660                        continue;
 661                /*
 662                 * If we have fewer left, left_first is set and we omit
 663                 * commits on the left branch in this loop.
 664                 */
 665                if (left_first == !!(flags & SYMMETRIC_LEFT))
 666                        continue;
 667
 668                /*
 669                 * Have we seen the same patch id?
 670                 */
 671                id = has_commit_patch_id(commit, &ids);
 672                if (!id)
 673                        continue;
 674                id->seen = 1;
 675                commit->object.flags |= cherry_flag;
 676        }
 677
 678        /* Now check the original side for seen ones */
 679        for (p = list; p; p = p->next) {
 680                struct commit *commit = p->item;
 681                struct patch_id *ent;
 682
 683                ent = commit->util;
 684                if (!ent)
 685                        continue;
 686                if (ent->seen)
 687                        commit->object.flags |= cherry_flag;
 688                commit->util = NULL;
 689        }
 690
 691        free_patch_ids(&ids);
 692}
 693
 694/* How many extra uninteresting commits we want to see.. */
 695#define SLOP 5
 696
 697static int still_interesting(struct commit_list *src, unsigned long date, int slop)
 698{
 699        /*
 700         * No source list at all? We're definitely done..
 701         */
 702        if (!src)
 703                return 0;
 704
 705        /*
 706         * Does the destination list contain entries with a date
 707         * before the source list? Definitely _not_ done.
 708         */
 709        if (date < src->item->date)
 710                return SLOP;
 711
 712        /*
 713         * Does the source list still have interesting commits in
 714         * it? Definitely not done..
 715         */
 716        if (!everybody_uninteresting(src))
 717                return SLOP;
 718
 719        /* Ok, we're closing in.. */
 720        return slop-1;
 721}
 722
 723/*
 724 * "rev-list --ancestry-path A..B" computes commits that are ancestors
 725 * of B but not ancestors of A but further limits the result to those
 726 * that are descendants of A.  This takes the list of bottom commits and
 727 * the result of "A..B" without --ancestry-path, and limits the latter
 728 * further to the ones that can reach one of the commits in "bottom".
 729 */
 730static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *list)
 731{
 732        struct commit_list *p;
 733        struct commit_list *rlist = NULL;
 734        int made_progress;
 735
 736        /*
 737         * Reverse the list so that it will be likely that we would
 738         * process parents before children.
 739         */
 740        for (p = list; p; p = p->next)
 741                commit_list_insert(p->item, &rlist);
 742
 743        for (p = bottom; p; p = p->next)
 744                p->item->object.flags |= TMP_MARK;
 745
 746        /*
 747         * Mark the ones that can reach bottom commits in "list",
 748         * in a bottom-up fashion.
 749         */
 750        do {
 751                made_progress = 0;
 752                for (p = rlist; p; p = p->next) {
 753                        struct commit *c = p->item;
 754                        struct commit_list *parents;
 755                        if (c->object.flags & (TMP_MARK | UNINTERESTING))
 756                                continue;
 757                        for (parents = c->parents;
 758                             parents;
 759                             parents = parents->next) {
 760                                if (!(parents->item->object.flags & TMP_MARK))
 761                                        continue;
 762                                c->object.flags |= TMP_MARK;
 763                                made_progress = 1;
 764                                break;
 765                        }
 766                }
 767        } while (made_progress);
 768
 769        /*
 770         * NEEDSWORK: decide if we want to remove parents that are
 771         * not marked with TMP_MARK from commit->parents for commits
 772         * in the resulting list.  We may not want to do that, though.
 773         */
 774
 775        /*
 776         * The ones that are not marked with TMP_MARK are uninteresting
 777         */
 778        for (p = list; p; p = p->next) {
 779                struct commit *c = p->item;
 780                if (c->object.flags & TMP_MARK)
 781                        continue;
 782                c->object.flags |= UNINTERESTING;
 783        }
 784
 785        /* We are done with the TMP_MARK */
 786        for (p = list; p; p = p->next)
 787                p->item->object.flags &= ~TMP_MARK;
 788        for (p = bottom; p; p = p->next)
 789                p->item->object.flags &= ~TMP_MARK;
 790        free_commit_list(rlist);
 791}
 792
 793/*
 794 * Before walking the history, keep the set of "negative" refs the
 795 * caller has asked to exclude.
 796 *
 797 * This is used to compute "rev-list --ancestry-path A..B", as we need
 798 * to filter the result of "A..B" further to the ones that can actually
 799 * reach A.
 800 */
 801static struct commit_list *collect_bottom_commits(struct rev_info *revs)
 802{
 803        struct commit_list *bottom = NULL;
 804        int i;
 805        for (i = 0; i < revs->cmdline.nr; i++) {
 806                struct rev_cmdline_entry *elem = &revs->cmdline.rev[i];
 807                if ((elem->flags & UNINTERESTING) &&
 808                    elem->item->type == OBJ_COMMIT)
 809                        commit_list_insert((struct commit *)elem->item, &bottom);
 810        }
 811        return bottom;
 812}
 813
 814/* Assumes either left_only or right_only is set */
 815static void limit_left_right(struct commit_list *list, struct rev_info *revs)
 816{
 817        struct commit_list *p;
 818
 819        for (p = list; p; p = p->next) {
 820                struct commit *commit = p->item;
 821
 822                if (revs->right_only) {
 823                        if (commit->object.flags & SYMMETRIC_LEFT)
 824                                commit->object.flags |= SHOWN;
 825                } else  /* revs->left_only is set */
 826                        if (!(commit->object.flags & SYMMETRIC_LEFT))
 827                                commit->object.flags |= SHOWN;
 828        }
 829}
 830
 831static int limit_list(struct rev_info *revs)
 832{
 833        int slop = SLOP;
 834        unsigned long date = ~0ul;
 835        struct commit_list *list = revs->commits;
 836        struct commit_list *newlist = NULL;
 837        struct commit_list **p = &newlist;
 838        struct commit_list *bottom = NULL;
 839
 840        if (revs->ancestry_path) {
 841                bottom = collect_bottom_commits(revs);
 842                if (!bottom)
 843                        die("--ancestry-path given but there are no bottom commits");
 844        }
 845
 846        while (list) {
 847                struct commit_list *entry = list;
 848                struct commit *commit = list->item;
 849                struct object *obj = &commit->object;
 850                show_early_output_fn_t show;
 851
 852                list = list->next;
 853                free(entry);
 854
 855                if (revs->max_age != -1 && (commit->date < revs->max_age))
 856                        obj->flags |= UNINTERESTING;
 857                if (add_parents_to_list(revs, commit, &list, NULL) < 0)
 858                        return -1;
 859                if (obj->flags & UNINTERESTING) {
 860                        mark_parents_uninteresting(commit);
 861                        if (revs->show_all)
 862                                p = &commit_list_insert(commit, p)->next;
 863                        slop = still_interesting(list, date, slop);
 864                        if (slop)
 865                                continue;
 866                        /* If showing all, add the whole pending list to the end */
 867                        if (revs->show_all)
 868                                *p = list;
 869                        break;
 870                }
 871                if (revs->min_age != -1 && (commit->date > revs->min_age))
 872                        continue;
 873                date = commit->date;
 874                p = &commit_list_insert(commit, p)->next;
 875
 876                show = show_early_output;
 877                if (!show)
 878                        continue;
 879
 880                show(revs, newlist);
 881                show_early_output = NULL;
 882        }
 883        if (revs->cherry_pick || revs->cherry_mark)
 884                cherry_pick_list(newlist, revs);
 885
 886        if (revs->left_only || revs->right_only)
 887                limit_left_right(newlist, revs);
 888
 889        if (bottom) {
 890                limit_to_ancestry(bottom, newlist);
 891                free_commit_list(bottom);
 892        }
 893
 894        revs->commits = newlist;
 895        return 0;
 896}
 897
 898static void add_rev_cmdline(struct rev_info *revs,
 899                            struct object *item,
 900                            const char *name,
 901                            int whence,
 902                            unsigned flags)
 903{
 904        struct rev_cmdline_info *info = &revs->cmdline;
 905        int nr = info->nr;
 906
 907        ALLOC_GROW(info->rev, nr + 1, info->alloc);
 908        info->rev[nr].item = item;
 909        info->rev[nr].name = name;
 910        info->rev[nr].whence = whence;
 911        info->rev[nr].flags = flags;
 912        info->nr++;
 913}
 914
 915struct all_refs_cb {
 916        int all_flags;
 917        int warned_bad_reflog;
 918        struct rev_info *all_revs;
 919        const char *name_for_errormsg;
 920};
 921
 922static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 923{
 924        struct all_refs_cb *cb = cb_data;
 925        struct object *object = get_reference(cb->all_revs, path, sha1,
 926                                              cb->all_flags);
 927        add_rev_cmdline(cb->all_revs, object, path, REV_CMD_REF, cb->all_flags);
 928        add_pending_sha1(cb->all_revs, path, sha1, cb->all_flags);
 929        return 0;
 930}
 931
 932static void init_all_refs_cb(struct all_refs_cb *cb, struct rev_info *revs,
 933        unsigned flags)
 934{
 935        cb->all_revs = revs;
 936        cb->all_flags = flags;
 937}
 938
 939static void handle_refs(const char *submodule, struct rev_info *revs, unsigned flags,
 940                int (*for_each)(const char *, each_ref_fn, void *))
 941{
 942        struct all_refs_cb cb;
 943        init_all_refs_cb(&cb, revs, flags);
 944        for_each(submodule, handle_one_ref, &cb);
 945}
 946
 947static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
 948{
 949        struct all_refs_cb *cb = cb_data;
 950        if (!is_null_sha1(sha1)) {
 951                struct object *o = parse_object(sha1);
 952                if (o) {
 953                        o->flags |= cb->all_flags;
 954                        /* ??? CMDLINEFLAGS ??? */
 955                        add_pending_object(cb->all_revs, o, "");
 956                }
 957                else if (!cb->warned_bad_reflog) {
 958                        warning("reflog of '%s' references pruned commits",
 959                                cb->name_for_errormsg);
 960                        cb->warned_bad_reflog = 1;
 961                }
 962        }
 963}
 964
 965static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 966                const char *email, unsigned long timestamp, int tz,
 967                const char *message, void *cb_data)
 968{
 969        handle_one_reflog_commit(osha1, cb_data);
 970        handle_one_reflog_commit(nsha1, cb_data);
 971        return 0;
 972}
 973
 974static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 975{
 976        struct all_refs_cb *cb = cb_data;
 977        cb->warned_bad_reflog = 0;
 978        cb->name_for_errormsg = path;
 979        for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
 980        return 0;
 981}
 982
 983static void handle_reflog(struct rev_info *revs, unsigned flags)
 984{
 985        struct all_refs_cb cb;
 986        cb.all_revs = revs;
 987        cb.all_flags = flags;
 988        for_each_reflog(handle_one_reflog, &cb);
 989}
 990
 991static int add_parents_only(struct rev_info *revs, const char *arg_, int flags)
 992{
 993        unsigned char sha1[20];
 994        struct object *it;
 995        struct commit *commit;
 996        struct commit_list *parents;
 997        const char *arg = arg_;
 998
 999        if (*arg == '^') {
1000                flags ^= UNINTERESTING;
1001                arg++;
1002        }
1003        if (get_sha1(arg, sha1))
1004                return 0;
1005        while (1) {
1006                it = get_reference(revs, arg, sha1, 0);
1007                if (!it && revs->ignore_missing)
1008                        return 0;
1009                if (it->type != OBJ_TAG)
1010                        break;
1011                if (!((struct tag*)it)->tagged)
1012                        return 0;
1013                hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
1014        }
1015        if (it->type != OBJ_COMMIT)
1016                return 0;
1017        commit = (struct commit *)it;
1018        for (parents = commit->parents; parents; parents = parents->next) {
1019                it = &parents->item->object;
1020                it->flags |= flags;
1021                add_rev_cmdline(revs, it, arg_, REV_CMD_PARENTS_ONLY, flags);
1022                add_pending_object(revs, it, arg);
1023        }
1024        return 1;
1025}
1026
1027void init_revisions(struct rev_info *revs, const char *prefix)
1028{
1029        memset(revs, 0, sizeof(*revs));
1030
1031        revs->abbrev = DEFAULT_ABBREV;
1032        revs->ignore_merges = 1;
1033        revs->simplify_history = 1;
1034        DIFF_OPT_SET(&revs->pruning, RECURSIVE);
1035        DIFF_OPT_SET(&revs->pruning, QUICK);
1036        revs->pruning.add_remove = file_add_remove;
1037        revs->pruning.change = file_change;
1038        revs->lifo = 1;
1039        revs->dense = 1;
1040        revs->prefix = prefix;
1041        revs->max_age = -1;
1042        revs->min_age = -1;
1043        revs->skip_count = -1;
1044        revs->max_count = -1;
1045        revs->max_parents = -1;
1046
1047        revs->commit_format = CMIT_FMT_DEFAULT;
1048
1049        revs->grep_filter.status_only = 1;
1050        revs->grep_filter.pattern_tail = &(revs->grep_filter.pattern_list);
1051        revs->grep_filter.header_tail = &(revs->grep_filter.header_list);
1052        revs->grep_filter.regflags = REG_NEWLINE;
1053
1054        diff_setup(&revs->diffopt);
1055        if (prefix && !revs->diffopt.prefix) {
1056                revs->diffopt.prefix = prefix;
1057                revs->diffopt.prefix_length = strlen(prefix);
1058        }
1059
1060        revs->notes_opt.use_default_notes = -1;
1061}
1062
1063static void add_pending_commit_list(struct rev_info *revs,
1064                                    struct commit_list *commit_list,
1065                                    unsigned int flags)
1066{
1067        while (commit_list) {
1068                struct object *object = &commit_list->item->object;
1069                object->flags |= flags;
1070                add_pending_object(revs, object, sha1_to_hex(object->sha1));
1071                commit_list = commit_list->next;
1072        }
1073}
1074
1075static void prepare_show_merge(struct rev_info *revs)
1076{
1077        struct commit_list *bases;
1078        struct commit *head, *other;
1079        unsigned char sha1[20];
1080        const char **prune = NULL;
1081        int i, prune_num = 1; /* counting terminating NULL */
1082
1083        if (get_sha1("HEAD", sha1))
1084                die("--merge without HEAD?");
1085        head = lookup_commit_or_die(sha1, "HEAD");
1086        if (get_sha1("MERGE_HEAD", sha1))
1087                die("--merge without MERGE_HEAD?");
1088        other = lookup_commit_or_die(sha1, "MERGE_HEAD");
1089        add_pending_object(revs, &head->object, "HEAD");
1090        add_pending_object(revs, &other->object, "MERGE_HEAD");
1091        bases = get_merge_bases(head, other, 1);
1092        add_pending_commit_list(revs, bases, UNINTERESTING);
1093        free_commit_list(bases);
1094        head->object.flags |= SYMMETRIC_LEFT;
1095
1096        if (!active_nr)
1097                read_cache();
1098        for (i = 0; i < active_nr; i++) {
1099                struct cache_entry *ce = active_cache[i];
1100                if (!ce_stage(ce))
1101                        continue;
1102                if (ce_path_match(ce, &revs->prune_data)) {
1103                        prune_num++;
1104                        prune = xrealloc(prune, sizeof(*prune) * prune_num);
1105                        prune[prune_num-2] = ce->name;
1106                        prune[prune_num-1] = NULL;
1107                }
1108                while ((i+1 < active_nr) &&
1109                       ce_same_name(ce, active_cache[i+1]))
1110                        i++;
1111        }
1112        free_pathspec(&revs->prune_data);
1113        init_pathspec(&revs->prune_data, prune);
1114        revs->limited = 1;
1115}
1116
1117int handle_revision_arg(const char *arg_, struct rev_info *revs,
1118                        int flags,
1119                        int cant_be_filename)
1120{
1121        unsigned mode;
1122        char *dotdot;
1123        struct object *object;
1124        unsigned char sha1[20];
1125        int local_flags;
1126        const char *arg = arg_;
1127
1128        dotdot = strstr(arg, "..");
1129        if (dotdot) {
1130                unsigned char from_sha1[20];
1131                const char *next = dotdot + 2;
1132                const char *this = arg;
1133                int symmetric = *next == '.';
1134                unsigned int flags_exclude = flags ^ UNINTERESTING;
1135                static const char head_by_default[] = "HEAD";
1136                unsigned int a_flags;
1137
1138                *dotdot = 0;
1139                next += symmetric;
1140
1141                if (!*next)
1142                        next = head_by_default;
1143                if (dotdot == arg)
1144                        this = head_by_default;
1145                if (this == head_by_default && next == head_by_default &&
1146                    !symmetric) {
1147                        /*
1148                         * Just ".."?  That is not a range but the
1149                         * pathspec for the parent directory.
1150                         */
1151                        if (!cant_be_filename) {
1152                                *dotdot = '.';
1153                                return -1;
1154                        }
1155                }
1156                if (!get_sha1(this, from_sha1) &&
1157                    !get_sha1(next, sha1)) {
1158                        struct commit *a, *b;
1159                        struct commit_list *exclude;
1160
1161                        a = lookup_commit_reference(from_sha1);
1162                        b = lookup_commit_reference(sha1);
1163                        if (!a || !b) {
1164                                if (revs->ignore_missing)
1165                                        return 0;
1166                                die(symmetric ?
1167                                    "Invalid symmetric difference expression %s...%s" :
1168                                    "Invalid revision range %s..%s",
1169                                    arg, next);
1170                        }
1171
1172                        if (!cant_be_filename) {
1173                                *dotdot = '.';
1174                                verify_non_filename(revs->prefix, arg);
1175                        }
1176
1177                        if (symmetric) {
1178                                exclude = get_merge_bases(a, b, 1);
1179                                add_pending_commit_list(revs, exclude,
1180                                                        flags_exclude);
1181                                free_commit_list(exclude);
1182                                a_flags = flags | SYMMETRIC_LEFT;
1183                        } else
1184                                a_flags = flags_exclude;
1185                        a->object.flags |= a_flags;
1186                        b->object.flags |= flags;
1187                        add_rev_cmdline(revs, &a->object, this,
1188                                        REV_CMD_LEFT, a_flags);
1189                        add_rev_cmdline(revs, &b->object, next,
1190                                        REV_CMD_RIGHT, flags);
1191                        add_pending_object(revs, &a->object, this);
1192                        add_pending_object(revs, &b->object, next);
1193                        return 0;
1194                }
1195                *dotdot = '.';
1196        }
1197        dotdot = strstr(arg, "^@");
1198        if (dotdot && !dotdot[2]) {
1199                *dotdot = 0;
1200                if (add_parents_only(revs, arg, flags))
1201                        return 0;
1202                *dotdot = '^';
1203        }
1204        dotdot = strstr(arg, "^!");
1205        if (dotdot && !dotdot[2]) {
1206                *dotdot = 0;
1207                if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
1208                        *dotdot = '^';
1209        }
1210
1211        local_flags = 0;
1212        if (*arg == '^') {
1213                local_flags = UNINTERESTING;
1214                arg++;
1215        }
1216        if (get_sha1_with_mode(arg, sha1, &mode))
1217                return revs->ignore_missing ? 0 : -1;
1218        if (!cant_be_filename)
1219                verify_non_filename(revs->prefix, arg);
1220        object = get_reference(revs, arg, sha1, flags ^ local_flags);
1221        add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
1222        add_pending_object_with_mode(revs, object, arg, mode);
1223        return 0;
1224}
1225
1226struct cmdline_pathspec {
1227        int alloc;
1228        int nr;
1229        const char **path;
1230};
1231
1232static void append_prune_data(struct cmdline_pathspec *prune, const char **av)
1233{
1234        while (*av) {
1235                ALLOC_GROW(prune->path, prune->nr+1, prune->alloc);
1236                prune->path[prune->nr++] = *(av++);
1237        }
1238}
1239
1240static void read_pathspec_from_stdin(struct rev_info *revs, struct strbuf *sb,
1241                                     struct cmdline_pathspec *prune)
1242{
1243        while (strbuf_getwholeline(sb, stdin, '\n') != EOF) {
1244                int len = sb->len;
1245                if (len && sb->buf[len - 1] == '\n')
1246                        sb->buf[--len] = '\0';
1247                ALLOC_GROW(prune->path, prune->nr+1, prune->alloc);
1248                prune->path[prune->nr++] = xstrdup(sb->buf);
1249        }
1250}
1251
1252static void read_revisions_from_stdin(struct rev_info *revs,
1253                                      struct cmdline_pathspec *prune)
1254{
1255        struct strbuf sb;
1256        int seen_dashdash = 0;
1257
1258        strbuf_init(&sb, 1000);
1259        while (strbuf_getwholeline(&sb, stdin, '\n') != EOF) {
1260                int len = sb.len;
1261                if (len && sb.buf[len - 1] == '\n')
1262                        sb.buf[--len] = '\0';
1263                if (!len)
1264                        break;
1265                if (sb.buf[0] == '-') {
1266                        if (len == 2 && sb.buf[1] == '-') {
1267                                seen_dashdash = 1;
1268                                break;
1269                        }
1270                        die("options not supported in --stdin mode");
1271                }
1272                if (handle_revision_arg(sb.buf, revs, 0, 1))
1273                        die("bad revision '%s'", sb.buf);
1274        }
1275        if (seen_dashdash)
1276                read_pathspec_from_stdin(revs, &sb, prune);
1277        strbuf_release(&sb);
1278}
1279
1280static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
1281{
1282        append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
1283}
1284
1285static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
1286{
1287        append_header_grep_pattern(&revs->grep_filter, field, pattern);
1288}
1289
1290static void add_message_grep(struct rev_info *revs, const char *pattern)
1291{
1292        add_grep(revs, pattern, GREP_PATTERN_BODY);
1293}
1294
1295static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
1296                               int *unkc, const char **unkv)
1297{
1298        const char *arg = argv[0];
1299        const char *optarg;
1300        int argcount;
1301
1302        /* pseudo revision arguments */
1303        if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
1304            !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
1305            !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
1306            !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
1307            !strcmp(arg, "--bisect") || !prefixcmp(arg, "--glob=") ||
1308            !prefixcmp(arg, "--branches=") || !prefixcmp(arg, "--tags=") ||
1309            !prefixcmp(arg, "--remotes="))
1310        {
1311                unkv[(*unkc)++] = arg;
1312                return 1;
1313        }
1314
1315        if ((argcount = parse_long_opt("max-count", argv, &optarg))) {
1316                revs->max_count = atoi(optarg);
1317                revs->no_walk = 0;
1318                return argcount;
1319        } else if ((argcount = parse_long_opt("skip", argv, &optarg))) {
1320                revs->skip_count = atoi(optarg);
1321                return argcount;
1322        } else if ((*arg == '-') && isdigit(arg[1])) {
1323        /* accept -<digit>, like traditional "head" */
1324                revs->max_count = atoi(arg + 1);
1325                revs->no_walk = 0;
1326        } else if (!strcmp(arg, "-n")) {
1327                if (argc <= 1)
1328                        return error("-n requires an argument");
1329                revs->max_count = atoi(argv[1]);
1330                revs->no_walk = 0;
1331                return 2;
1332        } else if (!prefixcmp(arg, "-n")) {
1333                revs->max_count = atoi(arg + 2);
1334                revs->no_walk = 0;
1335        } else if ((argcount = parse_long_opt("max-age", argv, &optarg))) {
1336                revs->max_age = atoi(optarg);
1337                return argcount;
1338        } else if ((argcount = parse_long_opt("since", argv, &optarg))) {
1339                revs->max_age = approxidate(optarg);
1340                return argcount;
1341        } else if ((argcount = parse_long_opt("after", argv, &optarg))) {
1342                revs->max_age = approxidate(optarg);
1343                return argcount;
1344        } else if ((argcount = parse_long_opt("min-age", argv, &optarg))) {
1345                revs->min_age = atoi(optarg);
1346                return argcount;
1347        } else if ((argcount = parse_long_opt("before", argv, &optarg))) {
1348                revs->min_age = approxidate(optarg);
1349                return argcount;
1350        } else if ((argcount = parse_long_opt("until", argv, &optarg))) {
1351                revs->min_age = approxidate(optarg);
1352                return argcount;
1353        } else if (!strcmp(arg, "--first-parent")) {
1354                revs->first_parent_only = 1;
1355        } else if (!strcmp(arg, "--ancestry-path")) {
1356                revs->ancestry_path = 1;
1357                revs->simplify_history = 0;
1358                revs->limited = 1;
1359        } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
1360                init_reflog_walk(&revs->reflog_info);
1361        } else if (!strcmp(arg, "--default")) {
1362                if (argc <= 1)
1363                        return error("bad --default argument");
1364                revs->def = argv[1];
1365                return 2;
1366        } else if (!strcmp(arg, "--merge")) {
1367                revs->show_merge = 1;
1368        } else if (!strcmp(arg, "--topo-order")) {
1369                revs->lifo = 1;
1370                revs->topo_order = 1;
1371        } else if (!strcmp(arg, "--simplify-merges")) {
1372                revs->simplify_merges = 1;
1373                revs->topo_order = 1;
1374                revs->rewrite_parents = 1;
1375                revs->simplify_history = 0;
1376                revs->limited = 1;
1377        } else if (!strcmp(arg, "--simplify-by-decoration")) {
1378                revs->simplify_merges = 1;
1379                revs->topo_order = 1;
1380                revs->rewrite_parents = 1;
1381                revs->simplify_history = 0;
1382                revs->simplify_by_decoration = 1;
1383                revs->limited = 1;
1384                revs->prune = 1;
1385                load_ref_decorations(DECORATE_SHORT_REFS);
1386        } else if (!strcmp(arg, "--date-order")) {
1387                revs->lifo = 0;
1388                revs->topo_order = 1;
1389        } else if (!prefixcmp(arg, "--early-output")) {
1390                int count = 100;
1391                switch (arg[14]) {
1392                case '=':
1393                        count = atoi(arg+15);
1394                        /* Fallthrough */
1395                case 0:
1396                        revs->topo_order = 1;
1397                       revs->early_output = count;
1398                }
1399        } else if (!strcmp(arg, "--parents")) {
1400                revs->rewrite_parents = 1;
1401                revs->print_parents = 1;
1402        } else if (!strcmp(arg, "--dense")) {
1403                revs->dense = 1;
1404        } else if (!strcmp(arg, "--sparse")) {
1405                revs->dense = 0;
1406        } else if (!strcmp(arg, "--show-all")) {
1407                revs->show_all = 1;
1408        } else if (!strcmp(arg, "--remove-empty")) {
1409                revs->remove_empty_trees = 1;
1410        } else if (!strcmp(arg, "--merges")) {
1411                revs->min_parents = 2;
1412        } else if (!strcmp(arg, "--no-merges")) {
1413                revs->max_parents = 1;
1414        } else if (!prefixcmp(arg, "--min-parents=")) {
1415                revs->min_parents = atoi(arg+14);
1416        } else if (!prefixcmp(arg, "--no-min-parents")) {
1417                revs->min_parents = 0;
1418        } else if (!prefixcmp(arg, "--max-parents=")) {
1419                revs->max_parents = atoi(arg+14);
1420        } else if (!prefixcmp(arg, "--no-max-parents")) {
1421                revs->max_parents = -1;
1422        } else if (!strcmp(arg, "--boundary")) {
1423                revs->boundary = 1;
1424        } else if (!strcmp(arg, "--left-right")) {
1425                revs->left_right = 1;
1426        } else if (!strcmp(arg, "--left-only")) {
1427                if (revs->right_only)
1428                        die("--left-only is incompatible with --right-only"
1429                            " or --cherry");
1430                revs->left_only = 1;
1431        } else if (!strcmp(arg, "--right-only")) {
1432                if (revs->left_only)
1433                        die("--right-only is incompatible with --left-only");
1434                revs->right_only = 1;
1435        } else if (!strcmp(arg, "--cherry")) {
1436                if (revs->left_only)
1437                        die("--cherry is incompatible with --left-only");
1438                revs->cherry_mark = 1;
1439                revs->right_only = 1;
1440                revs->max_parents = 1;
1441                revs->limited = 1;
1442        } else if (!strcmp(arg, "--count")) {
1443                revs->count = 1;
1444        } else if (!strcmp(arg, "--cherry-mark")) {
1445                if (revs->cherry_pick)
1446                        die("--cherry-mark is incompatible with --cherry-pick");
1447                revs->cherry_mark = 1;
1448                revs->limited = 1; /* needs limit_list() */
1449        } else if (!strcmp(arg, "--cherry-pick")) {
1450                if (revs->cherry_mark)
1451                        die("--cherry-pick is incompatible with --cherry-mark");
1452                revs->cherry_pick = 1;
1453                revs->limited = 1;
1454        } else if (!strcmp(arg, "--objects")) {
1455                revs->tag_objects = 1;
1456                revs->tree_objects = 1;
1457                revs->blob_objects = 1;
1458        } else if (!strcmp(arg, "--objects-edge")) {
1459                revs->tag_objects = 1;
1460                revs->tree_objects = 1;
1461                revs->blob_objects = 1;
1462                revs->edge_hint = 1;
1463        } else if (!strcmp(arg, "--verify-objects")) {
1464                revs->tag_objects = 1;
1465                revs->tree_objects = 1;
1466                revs->blob_objects = 1;
1467                revs->verify_objects = 1;
1468        } else if (!strcmp(arg, "--unpacked")) {
1469                revs->unpacked = 1;
1470        } else if (!prefixcmp(arg, "--unpacked=")) {
1471                die("--unpacked=<packfile> no longer supported.");
1472        } else if (!strcmp(arg, "-r")) {
1473                revs->diff = 1;
1474                DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1475        } else if (!strcmp(arg, "-t")) {
1476                revs->diff = 1;
1477                DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1478                DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1479        } else if (!strcmp(arg, "-m")) {
1480                revs->ignore_merges = 0;
1481        } else if (!strcmp(arg, "-c")) {
1482                revs->diff = 1;
1483                revs->dense_combined_merges = 0;
1484                revs->combine_merges = 1;
1485        } else if (!strcmp(arg, "--cc")) {
1486                revs->diff = 1;
1487                revs->dense_combined_merges = 1;
1488                revs->combine_merges = 1;
1489        } else if (!strcmp(arg, "-v")) {
1490                revs->verbose_header = 1;
1491        } else if (!strcmp(arg, "--pretty")) {
1492                revs->verbose_header = 1;
1493                revs->pretty_given = 1;
1494                get_commit_format(arg+8, revs);
1495        } else if (!prefixcmp(arg, "--pretty=") || !prefixcmp(arg, "--format=")) {
1496                /*
1497                 * Detached form ("--pretty X" as opposed to "--pretty=X")
1498                 * not allowed, since the argument is optional.
1499                 */
1500                revs->verbose_header = 1;
1501                revs->pretty_given = 1;
1502                get_commit_format(arg+9, revs);
1503        } else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
1504                revs->show_notes = 1;
1505                revs->show_notes_given = 1;
1506                revs->notes_opt.use_default_notes = 1;
1507        } else if (!strcmp(arg, "--show-signature")) {
1508                revs->show_signature = 1;
1509        } else if (!prefixcmp(arg, "--show-notes=") ||
1510                   !prefixcmp(arg, "--notes=")) {
1511                struct strbuf buf = STRBUF_INIT;
1512                revs->show_notes = 1;
1513                revs->show_notes_given = 1;
1514                if (!prefixcmp(arg, "--show-notes")) {
1515                        if (revs->notes_opt.use_default_notes < 0)
1516                                revs->notes_opt.use_default_notes = 1;
1517                        strbuf_addstr(&buf, arg+13);
1518                }
1519                else
1520                        strbuf_addstr(&buf, arg+8);
1521                expand_notes_ref(&buf);
1522                string_list_append(&revs->notes_opt.extra_notes_refs,
1523                                   strbuf_detach(&buf, NULL));
1524        } else if (!strcmp(arg, "--no-notes")) {
1525                revs->show_notes = 0;
1526                revs->show_notes_given = 1;
1527                revs->notes_opt.use_default_notes = -1;
1528                /* we have been strdup'ing ourselves, so trick
1529                 * string_list into free()ing strings */
1530                revs->notes_opt.extra_notes_refs.strdup_strings = 1;
1531                string_list_clear(&revs->notes_opt.extra_notes_refs, 0);
1532                revs->notes_opt.extra_notes_refs.strdup_strings = 0;
1533        } else if (!strcmp(arg, "--standard-notes")) {
1534                revs->show_notes_given = 1;
1535                revs->notes_opt.use_default_notes = 1;
1536        } else if (!strcmp(arg, "--no-standard-notes")) {
1537                revs->notes_opt.use_default_notes = 0;
1538        } else if (!strcmp(arg, "--oneline")) {
1539                revs->verbose_header = 1;
1540                get_commit_format("oneline", revs);
1541                revs->pretty_given = 1;
1542                revs->abbrev_commit = 1;
1543        } else if (!strcmp(arg, "--graph")) {
1544                revs->topo_order = 1;
1545                revs->rewrite_parents = 1;
1546                revs->graph = graph_init(revs);
1547        } else if (!strcmp(arg, "--root")) {
1548                revs->show_root_diff = 1;
1549        } else if (!strcmp(arg, "--no-commit-id")) {
1550                revs->no_commit_id = 1;
1551        } else if (!strcmp(arg, "--always")) {
1552                revs->always_show_header = 1;
1553        } else if (!strcmp(arg, "--no-abbrev")) {
1554                revs->abbrev = 0;
1555        } else if (!strcmp(arg, "--abbrev")) {
1556                revs->abbrev = DEFAULT_ABBREV;
1557        } else if (!prefixcmp(arg, "--abbrev=")) {
1558                revs->abbrev = strtoul(arg + 9, NULL, 10);
1559                if (revs->abbrev < MINIMUM_ABBREV)
1560                        revs->abbrev = MINIMUM_ABBREV;
1561                else if (revs->abbrev > 40)
1562                        revs->abbrev = 40;
1563        } else if (!strcmp(arg, "--abbrev-commit")) {
1564                revs->abbrev_commit = 1;
1565                revs->abbrev_commit_given = 1;
1566        } else if (!strcmp(arg, "--no-abbrev-commit")) {
1567                revs->abbrev_commit = 0;
1568        } else if (!strcmp(arg, "--full-diff")) {
1569                revs->diff = 1;
1570                revs->full_diff = 1;
1571        } else if (!strcmp(arg, "--full-history")) {
1572                revs->simplify_history = 0;
1573        } else if (!strcmp(arg, "--relative-date")) {
1574                revs->date_mode = DATE_RELATIVE;
1575                revs->date_mode_explicit = 1;
1576        } else if ((argcount = parse_long_opt("date", argv, &optarg))) {
1577                revs->date_mode = parse_date_format(optarg);
1578                revs->date_mode_explicit = 1;
1579                return argcount;
1580        } else if (!strcmp(arg, "--log-size")) {
1581                revs->show_log_size = 1;
1582        }
1583        /*
1584         * Grepping the commit log
1585         */
1586        else if ((argcount = parse_long_opt("author", argv, &optarg))) {
1587                add_header_grep(revs, GREP_HEADER_AUTHOR, optarg);
1588                return argcount;
1589        } else if ((argcount = parse_long_opt("committer", argv, &optarg))) {
1590                add_header_grep(revs, GREP_HEADER_COMMITTER, optarg);
1591                return argcount;
1592        } else if ((argcount = parse_long_opt("grep", argv, &optarg))) {
1593                add_message_grep(revs, optarg);
1594                return argcount;
1595        } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
1596                revs->grep_filter.regflags |= REG_EXTENDED;
1597        } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
1598                revs->grep_filter.regflags |= REG_ICASE;
1599                DIFF_OPT_SET(&revs->diffopt, PICKAXE_IGNORE_CASE);
1600        } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
1601                revs->grep_filter.fixed = 1;
1602        } else if (!strcmp(arg, "--all-match")) {
1603                revs->grep_filter.all_match = 1;
1604        } else if ((argcount = parse_long_opt("encoding", argv, &optarg))) {
1605                if (strcmp(optarg, "none"))
1606                        git_log_output_encoding = xstrdup(optarg);
1607                else
1608                        git_log_output_encoding = "";
1609                return argcount;
1610        } else if (!strcmp(arg, "--reverse")) {
1611                revs->reverse ^= 1;
1612        } else if (!strcmp(arg, "--children")) {
1613                revs->children.name = "children";
1614                revs->limited = 1;
1615        } else if (!strcmp(arg, "--ignore-missing")) {
1616                revs->ignore_missing = 1;
1617        } else {
1618                int opts = diff_opt_parse(&revs->diffopt, argv, argc);
1619                if (!opts)
1620                        unkv[(*unkc)++] = arg;
1621                return opts;
1622        }
1623
1624        return 1;
1625}
1626
1627void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
1628                        const struct option *options,
1629                        const char * const usagestr[])
1630{
1631        int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
1632                                    &ctx->cpidx, ctx->out);
1633        if (n <= 0) {
1634                error("unknown option `%s'", ctx->argv[0]);
1635                usage_with_options(usagestr, options);
1636        }
1637        ctx->argv += n;
1638        ctx->argc -= n;
1639}
1640
1641static int for_each_bad_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1642{
1643        return for_each_ref_in_submodule(submodule, "refs/bisect/bad", fn, cb_data);
1644}
1645
1646static int for_each_good_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1647{
1648        return for_each_ref_in_submodule(submodule, "refs/bisect/good", fn, cb_data);
1649}
1650
1651static int handle_revision_pseudo_opt(const char *submodule,
1652                                struct rev_info *revs,
1653                                int argc, const char **argv, int *flags)
1654{
1655        const char *arg = argv[0];
1656        const char *optarg;
1657        int argcount;
1658
1659        /*
1660         * NOTE!
1661         *
1662         * Commands like "git shortlog" will not accept the options below
1663         * unless parse_revision_opt queues them (as opposed to erroring
1664         * out).
1665         *
1666         * When implementing your new pseudo-option, remember to
1667         * register it in the list at the top of handle_revision_opt.
1668         */
1669        if (!strcmp(arg, "--all")) {
1670                handle_refs(submodule, revs, *flags, for_each_ref_submodule);
1671                handle_refs(submodule, revs, *flags, head_ref_submodule);
1672        } else if (!strcmp(arg, "--branches")) {
1673                handle_refs(submodule, revs, *flags, for_each_branch_ref_submodule);
1674        } else if (!strcmp(arg, "--bisect")) {
1675                handle_refs(submodule, revs, *flags, for_each_bad_bisect_ref);
1676                handle_refs(submodule, revs, *flags ^ UNINTERESTING, for_each_good_bisect_ref);
1677                revs->bisect = 1;
1678        } else if (!strcmp(arg, "--tags")) {
1679                handle_refs(submodule, revs, *flags, for_each_tag_ref_submodule);
1680        } else if (!strcmp(arg, "--remotes")) {
1681                handle_refs(submodule, revs, *flags, for_each_remote_ref_submodule);
1682        } else if ((argcount = parse_long_opt("glob", argv, &optarg))) {
1683                struct all_refs_cb cb;
1684                init_all_refs_cb(&cb, revs, *flags);
1685                for_each_glob_ref(handle_one_ref, optarg, &cb);
1686                return argcount;
1687        } else if (!prefixcmp(arg, "--branches=")) {
1688                struct all_refs_cb cb;
1689                init_all_refs_cb(&cb, revs, *flags);
1690                for_each_glob_ref_in(handle_one_ref, arg + 11, "refs/heads/", &cb);
1691        } else if (!prefixcmp(arg, "--tags=")) {
1692                struct all_refs_cb cb;
1693                init_all_refs_cb(&cb, revs, *flags);
1694                for_each_glob_ref_in(handle_one_ref, arg + 7, "refs/tags/", &cb);
1695        } else if (!prefixcmp(arg, "--remotes=")) {
1696                struct all_refs_cb cb;
1697                init_all_refs_cb(&cb, revs, *flags);
1698                for_each_glob_ref_in(handle_one_ref, arg + 10, "refs/remotes/", &cb);
1699        } else if (!strcmp(arg, "--reflog")) {
1700                handle_reflog(revs, *flags);
1701        } else if (!strcmp(arg, "--not")) {
1702                *flags ^= UNINTERESTING;
1703        } else if (!strcmp(arg, "--no-walk")) {
1704                revs->no_walk = 1;
1705        } else if (!strcmp(arg, "--do-walk")) {
1706                revs->no_walk = 0;
1707        } else {
1708                return 0;
1709        }
1710
1711        return 1;
1712}
1713
1714/*
1715 * Parse revision information, filling in the "rev_info" structure,
1716 * and removing the used arguments from the argument list.
1717 *
1718 * Returns the number of arguments left that weren't recognized
1719 * (which are also moved to the head of the argument list)
1720 */
1721int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
1722{
1723        int i, flags, left, seen_dashdash, read_from_stdin, got_rev_arg = 0;
1724        struct cmdline_pathspec prune_data;
1725        const char *submodule = NULL;
1726
1727        memset(&prune_data, 0, sizeof(prune_data));
1728        if (opt)
1729                submodule = opt->submodule;
1730
1731        /* First, search for "--" */
1732        if (opt && opt->assume_dashdash) {
1733                seen_dashdash = 1;
1734        } else {
1735                seen_dashdash = 0;
1736                for (i = 1; i < argc; i++) {
1737                        const char *arg = argv[i];
1738                        if (strcmp(arg, "--"))
1739                                continue;
1740                        argv[i] = NULL;
1741                        argc = i;
1742                        if (argv[i + 1])
1743                                append_prune_data(&prune_data, argv + i + 1);
1744                        seen_dashdash = 1;
1745                        break;
1746                }
1747        }
1748
1749        /* Second, deal with arguments and options */
1750        flags = 0;
1751        read_from_stdin = 0;
1752        for (left = i = 1; i < argc; i++) {
1753                const char *arg = argv[i];
1754                if (*arg == '-') {
1755                        int opts;
1756
1757                        opts = handle_revision_pseudo_opt(submodule,
1758                                                revs, argc - i, argv + i,
1759                                                &flags);
1760                        if (opts > 0) {
1761                                i += opts - 1;
1762                                continue;
1763                        }
1764
1765                        if (!strcmp(arg, "--stdin")) {
1766                                if (revs->disable_stdin) {
1767                                        argv[left++] = arg;
1768                                        continue;
1769                                }
1770                                if (read_from_stdin++)
1771                                        die("--stdin given twice?");
1772                                read_revisions_from_stdin(revs, &prune_data);
1773                                continue;
1774                        }
1775
1776                        opts = handle_revision_opt(revs, argc - i, argv + i, &left, argv);
1777                        if (opts > 0) {
1778                                i += opts - 1;
1779                                continue;
1780                        }
1781                        if (opts < 0)
1782                                exit(128);
1783                        continue;
1784                }
1785
1786                if (handle_revision_arg(arg, revs, flags, seen_dashdash)) {
1787                        int j;
1788                        if (seen_dashdash || *arg == '^')
1789                                die("bad revision '%s'", arg);
1790
1791                        /* If we didn't have a "--":
1792                         * (1) all filenames must exist;
1793                         * (2) all rev-args must not be interpretable
1794                         *     as a valid filename.
1795                         * but the latter we have checked in the main loop.
1796                         */
1797                        for (j = i; j < argc; j++)
1798                                verify_filename(revs->prefix, argv[j], j == i);
1799
1800                        append_prune_data(&prune_data, argv + i);
1801                        break;
1802                }
1803                else
1804                        got_rev_arg = 1;
1805        }
1806
1807        if (prune_data.nr) {
1808                /*
1809                 * If we need to introduce the magic "a lone ':' means no
1810                 * pathspec whatsoever", here is the place to do so.
1811                 *
1812                 * if (prune_data.nr == 1 && !strcmp(prune_data[0], ":")) {
1813                 *      prune_data.nr = 0;
1814                 *      prune_data.alloc = 0;
1815                 *      free(prune_data.path);
1816                 *      prune_data.path = NULL;
1817                 * } else {
1818                 *      terminate prune_data.alloc with NULL and
1819                 *      call init_pathspec() to set revs->prune_data here.
1820                 * }
1821                 */
1822                ALLOC_GROW(prune_data.path, prune_data.nr+1, prune_data.alloc);
1823                prune_data.path[prune_data.nr++] = NULL;
1824                init_pathspec(&revs->prune_data,
1825                              get_pathspec(revs->prefix, prune_data.path));
1826        }
1827
1828        if (revs->def == NULL)
1829                revs->def = opt ? opt->def : NULL;
1830        if (opt && opt->tweak)
1831                opt->tweak(revs, opt);
1832        if (revs->show_merge)
1833                prepare_show_merge(revs);
1834        if (revs->def && !revs->pending.nr && !got_rev_arg) {
1835                unsigned char sha1[20];
1836                struct object *object;
1837                unsigned mode;
1838                if (get_sha1_with_mode(revs->def, sha1, &mode))
1839                        die("bad default revision '%s'", revs->def);
1840                object = get_reference(revs, revs->def, sha1, 0);
1841                add_pending_object_with_mode(revs, object, revs->def, mode);
1842        }
1843
1844        /* Did the user ask for any diff output? Run the diff! */
1845        if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
1846                revs->diff = 1;
1847
1848        /* Pickaxe, diff-filter and rename following need diffs */
1849        if (revs->diffopt.pickaxe ||
1850            revs->diffopt.filter ||
1851            DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1852                revs->diff = 1;
1853
1854        if (revs->topo_order)
1855                revs->limited = 1;
1856
1857        if (revs->prune_data.nr) {
1858                diff_tree_setup_paths(revs->prune_data.raw, &revs->pruning);
1859                /* Can't prune commits with rename following: the paths change.. */
1860                if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1861                        revs->prune = 1;
1862                if (!revs->full_diff)
1863                        diff_tree_setup_paths(revs->prune_data.raw, &revs->diffopt);
1864        }
1865        if (revs->combine_merges)
1866                revs->ignore_merges = 0;
1867        revs->diffopt.abbrev = revs->abbrev;
1868        if (diff_setup_done(&revs->diffopt) < 0)
1869                die("diff_setup_done failed");
1870
1871        compile_grep_patterns(&revs->grep_filter);
1872
1873        if (revs->reverse && revs->reflog_info)
1874                die("cannot combine --reverse with --walk-reflogs");
1875        if (revs->rewrite_parents && revs->children.name)
1876                die("cannot combine --parents and --children");
1877
1878        /*
1879         * Limitations on the graph functionality
1880         */
1881        if (revs->reverse && revs->graph)
1882                die("cannot combine --reverse with --graph");
1883
1884        if (revs->reflog_info && revs->graph)
1885                die("cannot combine --walk-reflogs with --graph");
1886
1887        return left;
1888}
1889
1890static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
1891{
1892        struct commit_list *l = xcalloc(1, sizeof(*l));
1893
1894        l->item = child;
1895        l->next = add_decoration(&revs->children, &parent->object, l);
1896}
1897
1898static int remove_duplicate_parents(struct commit *commit)
1899{
1900        struct commit_list **pp, *p;
1901        int surviving_parents;
1902
1903        /* Examine existing parents while marking ones we have seen... */
1904        pp = &commit->parents;
1905        while ((p = *pp) != NULL) {
1906                struct commit *parent = p->item;
1907                if (parent->object.flags & TMP_MARK) {
1908                        *pp = p->next;
1909                        continue;
1910                }
1911                parent->object.flags |= TMP_MARK;
1912                pp = &p->next;
1913        }
1914        /* count them while clearing the temporary mark */
1915        surviving_parents = 0;
1916        for (p = commit->parents; p; p = p->next) {
1917                p->item->object.flags &= ~TMP_MARK;
1918                surviving_parents++;
1919        }
1920        return surviving_parents;
1921}
1922
1923struct merge_simplify_state {
1924        struct commit *simplified;
1925};
1926
1927static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
1928{
1929        struct merge_simplify_state *st;
1930
1931        st = lookup_decoration(&revs->merge_simplification, &commit->object);
1932        if (!st) {
1933                st = xcalloc(1, sizeof(*st));
1934                add_decoration(&revs->merge_simplification, &commit->object, st);
1935        }
1936        return st;
1937}
1938
1939static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
1940{
1941        struct commit_list *p;
1942        struct merge_simplify_state *st, *pst;
1943        int cnt;
1944
1945        st = locate_simplify_state(revs, commit);
1946
1947        /*
1948         * Have we handled this one?
1949         */
1950        if (st->simplified)
1951                return tail;
1952
1953        /*
1954         * An UNINTERESTING commit simplifies to itself, so does a
1955         * root commit.  We do not rewrite parents of such commit
1956         * anyway.
1957         */
1958        if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
1959                st->simplified = commit;
1960                return tail;
1961        }
1962
1963        /*
1964         * Do we know what commit all of our parents that matter
1965         * should be rewritten to?  Otherwise we are not ready to
1966         * rewrite this one yet.
1967         */
1968        for (cnt = 0, p = commit->parents; p; p = p->next) {
1969                pst = locate_simplify_state(revs, p->item);
1970                if (!pst->simplified) {
1971                        tail = &commit_list_insert(p->item, tail)->next;
1972                        cnt++;
1973                }
1974                if (revs->first_parent_only)
1975                        break;
1976        }
1977        if (cnt) {
1978                tail = &commit_list_insert(commit, tail)->next;
1979                return tail;
1980        }
1981
1982        /*
1983         * Rewrite our list of parents.
1984         */
1985        for (p = commit->parents; p; p = p->next) {
1986                pst = locate_simplify_state(revs, p->item);
1987                p->item = pst->simplified;
1988                if (revs->first_parent_only)
1989                        break;
1990        }
1991        if (!revs->first_parent_only)
1992                cnt = remove_duplicate_parents(commit);
1993        else
1994                cnt = 1;
1995
1996        /*
1997         * It is possible that we are a merge and one side branch
1998         * does not have any commit that touches the given paths;
1999         * in such a case, the immediate parents will be rewritten
2000         * to different commits.
2001         *
2002         *      o----X          X: the commit we are looking at;
2003         *     /    /           o: a commit that touches the paths;
2004         * ---o----'
2005         *
2006         * Further reduce the parents by removing redundant parents.
2007         */
2008        if (1 < cnt) {
2009                struct commit_list *h = reduce_heads(commit->parents);
2010                cnt = commit_list_count(h);
2011                free_commit_list(commit->parents);
2012                commit->parents = h;
2013        }
2014
2015        /*
2016         * A commit simplifies to itself if it is a root, if it is
2017         * UNINTERESTING, if it touches the given paths, or if it is a
2018         * merge and its parents simplifies to more than one commits
2019         * (the first two cases are already handled at the beginning of
2020         * this function).
2021         *
2022         * Otherwise, it simplifies to what its sole parent simplifies to.
2023         */
2024        if (!cnt ||
2025            (commit->object.flags & UNINTERESTING) ||
2026            !(commit->object.flags & TREESAME) ||
2027            (1 < cnt))
2028                st->simplified = commit;
2029        else {
2030                pst = locate_simplify_state(revs, commit->parents->item);
2031                st->simplified = pst->simplified;
2032        }
2033        return tail;
2034}
2035
2036static void simplify_merges(struct rev_info *revs)
2037{
2038        struct commit_list *list, *next;
2039        struct commit_list *yet_to_do, **tail;
2040        struct commit *commit;
2041
2042        if (!revs->prune)
2043                return;
2044
2045        /* feed the list reversed */
2046        yet_to_do = NULL;
2047        for (list = revs->commits; list; list = next) {
2048                commit = list->item;
2049                next = list->next;
2050                /*
2051                 * Do not free(list) here yet; the original list
2052                 * is used later in this function.
2053                 */
2054                commit_list_insert(commit, &yet_to_do);
2055        }
2056        while (yet_to_do) {
2057                list = yet_to_do;
2058                yet_to_do = NULL;
2059                tail = &yet_to_do;
2060                while (list) {
2061                        commit = list->item;
2062                        next = list->next;
2063                        free(list);
2064                        list = next;
2065                        tail = simplify_one(revs, commit, tail);
2066                }
2067        }
2068
2069        /* clean up the result, removing the simplified ones */
2070        list = revs->commits;
2071        revs->commits = NULL;
2072        tail = &revs->commits;
2073        while (list) {
2074                struct merge_simplify_state *st;
2075
2076                commit = list->item;
2077                next = list->next;
2078                free(list);
2079                list = next;
2080                st = locate_simplify_state(revs, commit);
2081                if (st->simplified == commit)
2082                        tail = &commit_list_insert(commit, tail)->next;
2083        }
2084}
2085
2086static void set_children(struct rev_info *revs)
2087{
2088        struct commit_list *l;
2089        for (l = revs->commits; l; l = l->next) {
2090                struct commit *commit = l->item;
2091                struct commit_list *p;
2092
2093                for (p = commit->parents; p; p = p->next)
2094                        add_child(revs, p->item, commit);
2095        }
2096}
2097
2098void reset_revision_walk(void)
2099{
2100        clear_object_flags(SEEN | ADDED | SHOWN);
2101}
2102
2103int prepare_revision_walk(struct rev_info *revs)
2104{
2105        int nr = revs->pending.nr;
2106        struct object_array_entry *e, *list;
2107        struct commit_list **next = &revs->commits;
2108
2109        e = list = revs->pending.objects;
2110        revs->pending.nr = 0;
2111        revs->pending.alloc = 0;
2112        revs->pending.objects = NULL;
2113        while (--nr >= 0) {
2114                struct commit *commit = handle_commit(revs, e->item, e->name);
2115                if (commit) {
2116                        if (!(commit->object.flags & SEEN)) {
2117                                commit->object.flags |= SEEN;
2118                                next = commit_list_append(commit, next);
2119                        }
2120                }
2121                e++;
2122        }
2123        commit_list_sort_by_date(&revs->commits);
2124        if (!revs->leak_pending)
2125                free(list);
2126
2127        if (revs->no_walk)
2128                return 0;
2129        if (revs->limited)
2130                if (limit_list(revs) < 0)
2131                        return -1;
2132        if (revs->topo_order)
2133                sort_in_topological_order(&revs->commits, revs->lifo);
2134        if (revs->simplify_merges)
2135                simplify_merges(revs);
2136        if (revs->children.name)
2137                set_children(revs);
2138        return 0;
2139}
2140
2141enum rewrite_result {
2142        rewrite_one_ok,
2143        rewrite_one_noparents,
2144        rewrite_one_error
2145};
2146
2147static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
2148{
2149        struct commit_list *cache = NULL;
2150
2151        for (;;) {
2152                struct commit *p = *pp;
2153                if (!revs->limited)
2154                        if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0)
2155                                return rewrite_one_error;
2156                if (p->parents && p->parents->next)
2157                        return rewrite_one_ok;
2158                if (p->object.flags & UNINTERESTING)
2159                        return rewrite_one_ok;
2160                if (!(p->object.flags & TREESAME))
2161                        return rewrite_one_ok;
2162                if (!p->parents)
2163                        return rewrite_one_noparents;
2164                *pp = p->parents->item;
2165        }
2166}
2167
2168static int rewrite_parents(struct rev_info *revs, struct commit *commit)
2169{
2170        struct commit_list **pp = &commit->parents;
2171        while (*pp) {
2172                struct commit_list *parent = *pp;
2173                switch (rewrite_one(revs, &parent->item)) {
2174                case rewrite_one_ok:
2175                        break;
2176                case rewrite_one_noparents:
2177                        *pp = parent->next;
2178                        continue;
2179                case rewrite_one_error:
2180                        return -1;
2181                }
2182                pp = &parent->next;
2183        }
2184        remove_duplicate_parents(commit);
2185        return 0;
2186}
2187
2188static int commit_match(struct commit *commit, struct rev_info *opt)
2189{
2190        if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
2191                return 1;
2192        return grep_buffer(&opt->grep_filter,
2193                           commit->buffer, strlen(commit->buffer));
2194}
2195
2196static inline int want_ancestry(struct rev_info *revs)
2197{
2198        return (revs->rewrite_parents || revs->children.name);
2199}
2200
2201enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
2202{
2203        if (commit->object.flags & SHOWN)
2204                return commit_ignore;
2205        if (revs->unpacked && has_sha1_pack(commit->object.sha1))
2206                return commit_ignore;
2207        if (revs->show_all)
2208                return commit_show;
2209        if (commit->object.flags & UNINTERESTING)
2210                return commit_ignore;
2211        if (revs->min_age != -1 && (commit->date > revs->min_age))
2212                return commit_ignore;
2213        if (revs->min_parents || (revs->max_parents >= 0)) {
2214                int n = 0;
2215                struct commit_list *p;
2216                for (p = commit->parents; p; p = p->next)
2217                        n++;
2218                if ((n < revs->min_parents) ||
2219                    ((revs->max_parents >= 0) && (n > revs->max_parents)))
2220                        return commit_ignore;
2221        }
2222        if (!commit_match(commit, revs))
2223                return commit_ignore;
2224        if (revs->prune && revs->dense) {
2225                /* Commit without changes? */
2226                if (commit->object.flags & TREESAME) {
2227                        /* drop merges unless we want parenthood */
2228                        if (!want_ancestry(revs))
2229                                return commit_ignore;
2230                        /* non-merge - always ignore it */
2231                        if (!commit->parents || !commit->parents->next)
2232                                return commit_ignore;
2233                }
2234        }
2235        return commit_show;
2236}
2237
2238enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
2239{
2240        enum commit_action action = get_commit_action(revs, commit);
2241
2242        if (action == commit_show &&
2243            !revs->show_all &&
2244            revs->prune && revs->dense && want_ancestry(revs)) {
2245                if (rewrite_parents(revs, commit) < 0)
2246                        return commit_error;
2247        }
2248        return action;
2249}
2250
2251static struct commit *get_revision_1(struct rev_info *revs)
2252{
2253        if (!revs->commits)
2254                return NULL;
2255
2256        do {
2257                struct commit_list *entry = revs->commits;
2258                struct commit *commit = entry->item;
2259
2260                revs->commits = entry->next;
2261                free(entry);
2262
2263                if (revs->reflog_info) {
2264                        fake_reflog_parent(revs->reflog_info, commit);
2265                        commit->object.flags &= ~(ADDED | SEEN | SHOWN);
2266                }
2267
2268                /*
2269                 * If we haven't done the list limiting, we need to look at
2270                 * the parents here. We also need to do the date-based limiting
2271                 * that we'd otherwise have done in limit_list().
2272                 */
2273                if (!revs->limited) {
2274                        if (revs->max_age != -1 &&
2275                            (commit->date < revs->max_age))
2276                                continue;
2277                        if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0)
2278                                die("Failed to traverse parents of commit %s",
2279                                    sha1_to_hex(commit->object.sha1));
2280                }
2281
2282                switch (simplify_commit(revs, commit)) {
2283                case commit_ignore:
2284                        continue;
2285                case commit_error:
2286                        die("Failed to simplify parents of commit %s",
2287                            sha1_to_hex(commit->object.sha1));
2288                default:
2289                        return commit;
2290                }
2291        } while (revs->commits);
2292        return NULL;
2293}
2294
2295static void gc_boundary(struct object_array *array)
2296{
2297        unsigned nr = array->nr;
2298        unsigned alloc = array->alloc;
2299        struct object_array_entry *objects = array->objects;
2300
2301        if (alloc <= nr) {
2302                unsigned i, j;
2303                for (i = j = 0; i < nr; i++) {
2304                        if (objects[i].item->flags & SHOWN)
2305                                continue;
2306                        if (i != j)
2307                                objects[j] = objects[i];
2308                        j++;
2309                }
2310                for (i = j; i < nr; i++)
2311                        objects[i].item = NULL;
2312                array->nr = j;
2313        }
2314}
2315
2316static void create_boundary_commit_list(struct rev_info *revs)
2317{
2318        unsigned i;
2319        struct commit *c;
2320        struct object_array *array = &revs->boundary_commits;
2321        struct object_array_entry *objects = array->objects;
2322
2323        /*
2324         * If revs->commits is non-NULL at this point, an error occurred in
2325         * get_revision_1().  Ignore the error and continue printing the
2326         * boundary commits anyway.  (This is what the code has always
2327         * done.)
2328         */
2329        if (revs->commits) {
2330                free_commit_list(revs->commits);
2331                revs->commits = NULL;
2332        }
2333
2334        /*
2335         * Put all of the actual boundary commits from revs->boundary_commits
2336         * into revs->commits
2337         */
2338        for (i = 0; i < array->nr; i++) {
2339                c = (struct commit *)(objects[i].item);
2340                if (!c)
2341                        continue;
2342                if (!(c->object.flags & CHILD_SHOWN))
2343                        continue;
2344                if (c->object.flags & (SHOWN | BOUNDARY))
2345                        continue;
2346                c->object.flags |= BOUNDARY;
2347                commit_list_insert(c, &revs->commits);
2348        }
2349
2350        /*
2351         * If revs->topo_order is set, sort the boundary commits
2352         * in topological order
2353         */
2354        sort_in_topological_order(&revs->commits, revs->lifo);
2355}
2356
2357static struct commit *get_revision_internal(struct rev_info *revs)
2358{
2359        struct commit *c = NULL;
2360        struct commit_list *l;
2361
2362        if (revs->boundary == 2) {
2363                /*
2364                 * All of the normal commits have already been returned,
2365                 * and we are now returning boundary commits.
2366                 * create_boundary_commit_list() has populated
2367                 * revs->commits with the remaining commits to return.
2368                 */
2369                c = pop_commit(&revs->commits);
2370                if (c)
2371                        c->object.flags |= SHOWN;
2372                return c;
2373        }
2374
2375        /*
2376         * Now pick up what they want to give us
2377         */
2378        c = get_revision_1(revs);
2379        if (c) {
2380                while (0 < revs->skip_count) {
2381                        revs->skip_count--;
2382                        c = get_revision_1(revs);
2383                        if (!c)
2384                                break;
2385                }
2386        }
2387
2388        /*
2389         * Check the max_count.
2390         */
2391        switch (revs->max_count) {
2392        case -1:
2393                break;
2394        case 0:
2395                c = NULL;
2396                break;
2397        default:
2398                revs->max_count--;
2399        }
2400
2401        if (c)
2402                c->object.flags |= SHOWN;
2403
2404        if (!revs->boundary) {
2405                return c;
2406        }
2407
2408        if (!c) {
2409                /*
2410                 * get_revision_1() runs out the commits, and
2411                 * we are done computing the boundaries.
2412                 * switch to boundary commits output mode.
2413                 */
2414                revs->boundary = 2;
2415
2416                /*
2417                 * Update revs->commits to contain the list of
2418                 * boundary commits.
2419                 */
2420                create_boundary_commit_list(revs);
2421
2422                return get_revision_internal(revs);
2423        }
2424
2425        /*
2426         * boundary commits are the commits that are parents of the
2427         * ones we got from get_revision_1() but they themselves are
2428         * not returned from get_revision_1().  Before returning
2429         * 'c', we need to mark its parents that they could be boundaries.
2430         */
2431
2432        for (l = c->parents; l; l = l->next) {
2433                struct object *p;
2434                p = &(l->item->object);
2435                if (p->flags & (CHILD_SHOWN | SHOWN))
2436                        continue;
2437                p->flags |= CHILD_SHOWN;
2438                gc_boundary(&revs->boundary_commits);
2439                add_object_array(p, NULL, &revs->boundary_commits);
2440        }
2441
2442        return c;
2443}
2444
2445struct commit *get_revision(struct rev_info *revs)
2446{
2447        struct commit *c;
2448        struct commit_list *reversed;
2449
2450        if (revs->reverse) {
2451                reversed = NULL;
2452                while ((c = get_revision_internal(revs))) {
2453                        commit_list_insert(c, &reversed);
2454                }
2455                revs->commits = reversed;
2456                revs->reverse = 0;
2457                revs->reverse_output_stage = 1;
2458        }
2459
2460        if (revs->reverse_output_stage)
2461                return pop_commit(&revs->commits);
2462
2463        c = get_revision_internal(revs);
2464        if (c && revs->graph)
2465                graph_update(revs->graph, c);
2466        return c;
2467}
2468
2469char *get_revision_mark(const struct rev_info *revs, const struct commit *commit)
2470{
2471        if (commit->object.flags & BOUNDARY)
2472                return "-";
2473        else if (commit->object.flags & UNINTERESTING)
2474                return "^";
2475        else if (commit->object.flags & PATCHSAME)
2476                return "=";
2477        else if (!revs || revs->left_right) {
2478                if (commit->object.flags & SYMMETRIC_LEFT)
2479                        return "<";
2480                else
2481                        return ">";
2482        } else if (revs->graph)
2483                return "*";
2484        else if (revs->cherry_mark)
2485                return "+";
2486        return "";
2487}
2488
2489void put_revision_mark(const struct rev_info *revs, const struct commit *commit)
2490{
2491        char *mark = get_revision_mark(revs, commit);
2492        if (!strlen(mark))
2493                return;
2494        fputs(mark, stdout);
2495        putchar(' ');
2496}