revision.con commit Merge branch 'jk/config-warn-on-inaccessible-paths' (7fe136d)
   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                    int sha1_valid,
 349                    const char *fullpath, unsigned dirty_submodule)
 350{
 351        int diff = addremove == '+' ? REV_TREE_NEW : REV_TREE_OLD;
 352
 353        tree_difference |= diff;
 354        if (tree_difference == REV_TREE_DIFFERENT)
 355                DIFF_OPT_SET(options, HAS_CHANGES);
 356}
 357
 358static void file_change(struct diff_options *options,
 359                 unsigned old_mode, unsigned new_mode,
 360                 const unsigned char *old_sha1,
 361                 const unsigned char *new_sha1,
 362                 int old_sha1_valid, int new_sha1_valid,
 363                 const char *fullpath,
 364                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
 365{
 366        tree_difference = REV_TREE_DIFFERENT;
 367        DIFF_OPT_SET(options, HAS_CHANGES);
 368}
 369
 370static int rev_compare_tree(struct rev_info *revs, struct commit *parent, struct commit *commit)
 371{
 372        struct tree *t1 = parent->tree;
 373        struct tree *t2 = commit->tree;
 374
 375        if (!t1)
 376                return REV_TREE_NEW;
 377        if (!t2)
 378                return REV_TREE_OLD;
 379
 380        if (revs->simplify_by_decoration) {
 381                /*
 382                 * If we are simplifying by decoration, then the commit
 383                 * is worth showing if it has a tag pointing at it.
 384                 */
 385                if (lookup_decoration(&name_decoration, &commit->object))
 386                        return REV_TREE_DIFFERENT;
 387                /*
 388                 * A commit that is not pointed by a tag is uninteresting
 389                 * if we are not limited by path.  This means that you will
 390                 * see the usual "commits that touch the paths" plus any
 391                 * tagged commit by specifying both --simplify-by-decoration
 392                 * and pathspec.
 393                 */
 394                if (!revs->prune_data.nr)
 395                        return REV_TREE_SAME;
 396        }
 397
 398        tree_difference = REV_TREE_SAME;
 399        DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 400        if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
 401                           &revs->pruning) < 0)
 402                return REV_TREE_DIFFERENT;
 403        return tree_difference;
 404}
 405
 406static int rev_same_tree_as_empty(struct rev_info *revs, struct commit *commit)
 407{
 408        int retval;
 409        void *tree;
 410        unsigned long size;
 411        struct tree_desc empty, real;
 412        struct tree *t1 = commit->tree;
 413
 414        if (!t1)
 415                return 0;
 416
 417        tree = read_object_with_reference(t1->object.sha1, tree_type, &size, NULL);
 418        if (!tree)
 419                return 0;
 420        init_tree_desc(&real, tree, size);
 421        init_tree_desc(&empty, "", 0);
 422
 423        tree_difference = REV_TREE_SAME;
 424        DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 425        retval = diff_tree(&empty, &real, "", &revs->pruning);
 426        free(tree);
 427
 428        return retval >= 0 && (tree_difference == REV_TREE_SAME);
 429}
 430
 431static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 432{
 433        struct commit_list **pp, *parent;
 434        int tree_changed = 0, tree_same = 0, nth_parent = 0;
 435
 436        /*
 437         * If we don't do pruning, everything is interesting
 438         */
 439        if (!revs->prune)
 440                return;
 441
 442        if (!commit->tree)
 443                return;
 444
 445        if (!commit->parents) {
 446                if (rev_same_tree_as_empty(revs, commit))
 447                        commit->object.flags |= TREESAME;
 448                return;
 449        }
 450
 451        /*
 452         * Normal non-merge commit? If we don't want to make the
 453         * history dense, we consider it always to be a change..
 454         */
 455        if (!revs->dense && !commit->parents->next)
 456                return;
 457
 458        pp = &commit->parents;
 459        while ((parent = *pp) != NULL) {
 460                struct commit *p = parent->item;
 461
 462                /*
 463                 * Do not compare with later parents when we care only about
 464                 * the first parent chain, in order to avoid derailing the
 465                 * traversal to follow a side branch that brought everything
 466                 * in the path we are limited to by the pathspec.
 467                 */
 468                if (revs->first_parent_only && nth_parent++)
 469                        break;
 470                if (parse_commit(p) < 0)
 471                        die("cannot simplify commit %s (because of %s)",
 472                            sha1_to_hex(commit->object.sha1),
 473                            sha1_to_hex(p->object.sha1));
 474                switch (rev_compare_tree(revs, p, commit)) {
 475                case REV_TREE_SAME:
 476                        tree_same = 1;
 477                        if (!revs->simplify_history || (p->object.flags & UNINTERESTING)) {
 478                                /* Even if a merge with an uninteresting
 479                                 * side branch brought the entire change
 480                                 * we are interested in, we do not want
 481                                 * to lose the other branches of this
 482                                 * merge, so we just keep going.
 483                                 */
 484                                pp = &parent->next;
 485                                continue;
 486                        }
 487                        parent->next = NULL;
 488                        commit->parents = parent;
 489                        commit->object.flags |= TREESAME;
 490                        return;
 491
 492                case REV_TREE_NEW:
 493                        if (revs->remove_empty_trees &&
 494                            rev_same_tree_as_empty(revs, p)) {
 495                                /* We are adding all the specified
 496                                 * paths from this parent, so the
 497                                 * history beyond this parent is not
 498                                 * interesting.  Remove its parents
 499                                 * (they are grandparents for us).
 500                                 * IOW, we pretend this parent is a
 501                                 * "root" commit.
 502                                 */
 503                                if (parse_commit(p) < 0)
 504                                        die("cannot simplify commit %s (invalid %s)",
 505                                            sha1_to_hex(commit->object.sha1),
 506                                            sha1_to_hex(p->object.sha1));
 507                                p->parents = NULL;
 508                        }
 509                /* fallthrough */
 510                case REV_TREE_OLD:
 511                case REV_TREE_DIFFERENT:
 512                        tree_changed = 1;
 513                        pp = &parent->next;
 514                        continue;
 515                }
 516                die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
 517        }
 518        if (tree_changed && !tree_same)
 519                return;
 520        commit->object.flags |= TREESAME;
 521}
 522
 523static void commit_list_insert_by_date_cached(struct commit *p, struct commit_list **head,
 524                    struct commit_list *cached_base, struct commit_list **cache)
 525{
 526        struct commit_list *new_entry;
 527
 528        if (cached_base && p->date < cached_base->item->date)
 529                new_entry = commit_list_insert_by_date(p, &cached_base->next);
 530        else
 531                new_entry = commit_list_insert_by_date(p, head);
 532
 533        if (cache && (!*cache || p->date < (*cache)->item->date))
 534                *cache = new_entry;
 535}
 536
 537static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
 538                    struct commit_list **list, struct commit_list **cache_ptr)
 539{
 540        struct commit_list *parent = commit->parents;
 541        unsigned left_flag;
 542        struct commit_list *cached_base = cache_ptr ? *cache_ptr : NULL;
 543
 544        if (commit->object.flags & ADDED)
 545                return 0;
 546        commit->object.flags |= ADDED;
 547
 548        /*
 549         * If the commit is uninteresting, don't try to
 550         * prune parents - we want the maximal uninteresting
 551         * set.
 552         *
 553         * Normally we haven't parsed the parent
 554         * yet, so we won't have a parent of a parent
 555         * here. However, it may turn out that we've
 556         * reached this commit some other way (where it
 557         * wasn't uninteresting), in which case we need
 558         * to mark its parents recursively too..
 559         */
 560        if (commit->object.flags & UNINTERESTING) {
 561                while (parent) {
 562                        struct commit *p = parent->item;
 563                        parent = parent->next;
 564                        if (p)
 565                                p->object.flags |= UNINTERESTING;
 566                        if (parse_commit(p) < 0)
 567                                continue;
 568                        if (p->parents)
 569                                mark_parents_uninteresting(p);
 570                        if (p->object.flags & SEEN)
 571                                continue;
 572                        p->object.flags |= SEEN;
 573                        commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
 574                }
 575                return 0;
 576        }
 577
 578        /*
 579         * Ok, the commit wasn't uninteresting. Try to
 580         * simplify the commit history and find the parent
 581         * that has no differences in the path set if one exists.
 582         */
 583        try_to_simplify_commit(revs, commit);
 584
 585        if (revs->no_walk)
 586                return 0;
 587
 588        left_flag = (commit->object.flags & SYMMETRIC_LEFT);
 589
 590        for (parent = commit->parents; parent; parent = parent->next) {
 591                struct commit *p = parent->item;
 592
 593                if (parse_commit(p) < 0)
 594                        return -1;
 595                if (revs->show_source && !p->util)
 596                        p->util = commit->util;
 597                p->object.flags |= left_flag;
 598                if (!(p->object.flags & SEEN)) {
 599                        p->object.flags |= SEEN;
 600                        commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
 601                }
 602                if (revs->first_parent_only)
 603                        break;
 604        }
 605        return 0;
 606}
 607
 608static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
 609{
 610        struct commit_list *p;
 611        int left_count = 0, right_count = 0;
 612        int left_first;
 613        struct patch_ids ids;
 614        unsigned cherry_flag;
 615
 616        /* First count the commits on the left and on the right */
 617        for (p = list; p; p = p->next) {
 618                struct commit *commit = p->item;
 619                unsigned flags = commit->object.flags;
 620                if (flags & BOUNDARY)
 621                        ;
 622                else if (flags & SYMMETRIC_LEFT)
 623                        left_count++;
 624                else
 625                        right_count++;
 626        }
 627
 628        if (!left_count || !right_count)
 629                return;
 630
 631        left_first = left_count < right_count;
 632        init_patch_ids(&ids);
 633        ids.diffopts.pathspec = revs->diffopt.pathspec;
 634
 635        /* Compute patch-ids for one side */
 636        for (p = list; p; p = p->next) {
 637                struct commit *commit = p->item;
 638                unsigned flags = commit->object.flags;
 639
 640                if (flags & BOUNDARY)
 641                        continue;
 642                /*
 643                 * If we have fewer left, left_first is set and we omit
 644                 * commits on the right branch in this loop.  If we have
 645                 * fewer right, we skip the left ones.
 646                 */
 647                if (left_first != !!(flags & SYMMETRIC_LEFT))
 648                        continue;
 649                commit->util = add_commit_patch_id(commit, &ids);
 650        }
 651
 652        /* either cherry_mark or cherry_pick are true */
 653        cherry_flag = revs->cherry_mark ? PATCHSAME : SHOWN;
 654
 655        /* Check the other side */
 656        for (p = list; p; p = p->next) {
 657                struct commit *commit = p->item;
 658                struct patch_id *id;
 659                unsigned flags = commit->object.flags;
 660
 661                if (flags & BOUNDARY)
 662                        continue;
 663                /*
 664                 * If we have fewer left, left_first is set and we omit
 665                 * commits on the left branch in this loop.
 666                 */
 667                if (left_first == !!(flags & SYMMETRIC_LEFT))
 668                        continue;
 669
 670                /*
 671                 * Have we seen the same patch id?
 672                 */
 673                id = has_commit_patch_id(commit, &ids);
 674                if (!id)
 675                        continue;
 676                id->seen = 1;
 677                commit->object.flags |= cherry_flag;
 678        }
 679
 680        /* Now check the original side for seen ones */
 681        for (p = list; p; p = p->next) {
 682                struct commit *commit = p->item;
 683                struct patch_id *ent;
 684
 685                ent = commit->util;
 686                if (!ent)
 687                        continue;
 688                if (ent->seen)
 689                        commit->object.flags |= cherry_flag;
 690                commit->util = NULL;
 691        }
 692
 693        free_patch_ids(&ids);
 694}
 695
 696/* How many extra uninteresting commits we want to see.. */
 697#define SLOP 5
 698
 699static int still_interesting(struct commit_list *src, unsigned long date, int slop)
 700{
 701        /*
 702         * No source list at all? We're definitely done..
 703         */
 704        if (!src)
 705                return 0;
 706
 707        /*
 708         * Does the destination list contain entries with a date
 709         * before the source list? Definitely _not_ done.
 710         */
 711        if (date < src->item->date)
 712                return SLOP;
 713
 714        /*
 715         * Does the source list still have interesting commits in
 716         * it? Definitely not done..
 717         */
 718        if (!everybody_uninteresting(src))
 719                return SLOP;
 720
 721        /* Ok, we're closing in.. */
 722        return slop-1;
 723}
 724
 725/*
 726 * "rev-list --ancestry-path A..B" computes commits that are ancestors
 727 * of B but not ancestors of A but further limits the result to those
 728 * that are descendants of A.  This takes the list of bottom commits and
 729 * the result of "A..B" without --ancestry-path, and limits the latter
 730 * further to the ones that can reach one of the commits in "bottom".
 731 */
 732static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *list)
 733{
 734        struct commit_list *p;
 735        struct commit_list *rlist = NULL;
 736        int made_progress;
 737
 738        /*
 739         * Reverse the list so that it will be likely that we would
 740         * process parents before children.
 741         */
 742        for (p = list; p; p = p->next)
 743                commit_list_insert(p->item, &rlist);
 744
 745        for (p = bottom; p; p = p->next)
 746                p->item->object.flags |= TMP_MARK;
 747
 748        /*
 749         * Mark the ones that can reach bottom commits in "list",
 750         * in a bottom-up fashion.
 751         */
 752        do {
 753                made_progress = 0;
 754                for (p = rlist; p; p = p->next) {
 755                        struct commit *c = p->item;
 756                        struct commit_list *parents;
 757                        if (c->object.flags & (TMP_MARK | UNINTERESTING))
 758                                continue;
 759                        for (parents = c->parents;
 760                             parents;
 761                             parents = parents->next) {
 762                                if (!(parents->item->object.flags & TMP_MARK))
 763                                        continue;
 764                                c->object.flags |= TMP_MARK;
 765                                made_progress = 1;
 766                                break;
 767                        }
 768                }
 769        } while (made_progress);
 770
 771        /*
 772         * NEEDSWORK: decide if we want to remove parents that are
 773         * not marked with TMP_MARK from commit->parents for commits
 774         * in the resulting list.  We may not want to do that, though.
 775         */
 776
 777        /*
 778         * The ones that are not marked with TMP_MARK are uninteresting
 779         */
 780        for (p = list; p; p = p->next) {
 781                struct commit *c = p->item;
 782                if (c->object.flags & TMP_MARK)
 783                        continue;
 784                c->object.flags |= UNINTERESTING;
 785        }
 786
 787        /* We are done with the TMP_MARK */
 788        for (p = list; p; p = p->next)
 789                p->item->object.flags &= ~TMP_MARK;
 790        for (p = bottom; p; p = p->next)
 791                p->item->object.flags &= ~TMP_MARK;
 792        free_commit_list(rlist);
 793}
 794
 795/*
 796 * Before walking the history, keep the set of "negative" refs the
 797 * caller has asked to exclude.
 798 *
 799 * This is used to compute "rev-list --ancestry-path A..B", as we need
 800 * to filter the result of "A..B" further to the ones that can actually
 801 * reach A.
 802 */
 803static struct commit_list *collect_bottom_commits(struct rev_info *revs)
 804{
 805        struct commit_list *bottom = NULL;
 806        int i;
 807        for (i = 0; i < revs->cmdline.nr; i++) {
 808                struct rev_cmdline_entry *elem = &revs->cmdline.rev[i];
 809                if ((elem->flags & UNINTERESTING) &&
 810                    elem->item->type == OBJ_COMMIT)
 811                        commit_list_insert((struct commit *)elem->item, &bottom);
 812        }
 813        return bottom;
 814}
 815
 816/* Assumes either left_only or right_only is set */
 817static void limit_left_right(struct commit_list *list, struct rev_info *revs)
 818{
 819        struct commit_list *p;
 820
 821        for (p = list; p; p = p->next) {
 822                struct commit *commit = p->item;
 823
 824                if (revs->right_only) {
 825                        if (commit->object.flags & SYMMETRIC_LEFT)
 826                                commit->object.flags |= SHOWN;
 827                } else  /* revs->left_only is set */
 828                        if (!(commit->object.flags & SYMMETRIC_LEFT))
 829                                commit->object.flags |= SHOWN;
 830        }
 831}
 832
 833static int limit_list(struct rev_info *revs)
 834{
 835        int slop = SLOP;
 836        unsigned long date = ~0ul;
 837        struct commit_list *list = revs->commits;
 838        struct commit_list *newlist = NULL;
 839        struct commit_list **p = &newlist;
 840        struct commit_list *bottom = NULL;
 841
 842        if (revs->ancestry_path) {
 843                bottom = collect_bottom_commits(revs);
 844                if (!bottom)
 845                        die("--ancestry-path given but there are no bottom commits");
 846        }
 847
 848        while (list) {
 849                struct commit_list *entry = list;
 850                struct commit *commit = list->item;
 851                struct object *obj = &commit->object;
 852                show_early_output_fn_t show;
 853
 854                list = list->next;
 855                free(entry);
 856
 857                if (revs->max_age != -1 && (commit->date < revs->max_age))
 858                        obj->flags |= UNINTERESTING;
 859                if (add_parents_to_list(revs, commit, &list, NULL) < 0)
 860                        return -1;
 861                if (obj->flags & UNINTERESTING) {
 862                        mark_parents_uninteresting(commit);
 863                        if (revs->show_all)
 864                                p = &commit_list_insert(commit, p)->next;
 865                        slop = still_interesting(list, date, slop);
 866                        if (slop)
 867                                continue;
 868                        /* If showing all, add the whole pending list to the end */
 869                        if (revs->show_all)
 870                                *p = list;
 871                        break;
 872                }
 873                if (revs->min_age != -1 && (commit->date > revs->min_age))
 874                        continue;
 875                date = commit->date;
 876                p = &commit_list_insert(commit, p)->next;
 877
 878                show = show_early_output;
 879                if (!show)
 880                        continue;
 881
 882                show(revs, newlist);
 883                show_early_output = NULL;
 884        }
 885        if (revs->cherry_pick || revs->cherry_mark)
 886                cherry_pick_list(newlist, revs);
 887
 888        if (revs->left_only || revs->right_only)
 889                limit_left_right(newlist, revs);
 890
 891        if (bottom) {
 892                limit_to_ancestry(bottom, newlist);
 893                free_commit_list(bottom);
 894        }
 895
 896        revs->commits = newlist;
 897        return 0;
 898}
 899
 900static void add_rev_cmdline(struct rev_info *revs,
 901                            struct object *item,
 902                            const char *name,
 903                            int whence,
 904                            unsigned flags)
 905{
 906        struct rev_cmdline_info *info = &revs->cmdline;
 907        int nr = info->nr;
 908
 909        ALLOC_GROW(info->rev, nr + 1, info->alloc);
 910        info->rev[nr].item = item;
 911        info->rev[nr].name = name;
 912        info->rev[nr].whence = whence;
 913        info->rev[nr].flags = flags;
 914        info->nr++;
 915}
 916
 917struct all_refs_cb {
 918        int all_flags;
 919        int warned_bad_reflog;
 920        struct rev_info *all_revs;
 921        const char *name_for_errormsg;
 922};
 923
 924static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 925{
 926        struct all_refs_cb *cb = cb_data;
 927        struct object *object = get_reference(cb->all_revs, path, sha1,
 928                                              cb->all_flags);
 929        add_rev_cmdline(cb->all_revs, object, path, REV_CMD_REF, cb->all_flags);
 930        add_pending_sha1(cb->all_revs, path, sha1, cb->all_flags);
 931        return 0;
 932}
 933
 934static void init_all_refs_cb(struct all_refs_cb *cb, struct rev_info *revs,
 935        unsigned flags)
 936{
 937        cb->all_revs = revs;
 938        cb->all_flags = flags;
 939}
 940
 941static void handle_refs(const char *submodule, struct rev_info *revs, unsigned flags,
 942                int (*for_each)(const char *, each_ref_fn, void *))
 943{
 944        struct all_refs_cb cb;
 945        init_all_refs_cb(&cb, revs, flags);
 946        for_each(submodule, handle_one_ref, &cb);
 947}
 948
 949static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
 950{
 951        struct all_refs_cb *cb = cb_data;
 952        if (!is_null_sha1(sha1)) {
 953                struct object *o = parse_object(sha1);
 954                if (o) {
 955                        o->flags |= cb->all_flags;
 956                        /* ??? CMDLINEFLAGS ??? */
 957                        add_pending_object(cb->all_revs, o, "");
 958                }
 959                else if (!cb->warned_bad_reflog) {
 960                        warning("reflog of '%s' references pruned commits",
 961                                cb->name_for_errormsg);
 962                        cb->warned_bad_reflog = 1;
 963                }
 964        }
 965}
 966
 967static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 968                const char *email, unsigned long timestamp, int tz,
 969                const char *message, void *cb_data)
 970{
 971        handle_one_reflog_commit(osha1, cb_data);
 972        handle_one_reflog_commit(nsha1, cb_data);
 973        return 0;
 974}
 975
 976static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 977{
 978        struct all_refs_cb *cb = cb_data;
 979        cb->warned_bad_reflog = 0;
 980        cb->name_for_errormsg = path;
 981        for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
 982        return 0;
 983}
 984
 985static void handle_reflog(struct rev_info *revs, unsigned flags)
 986{
 987        struct all_refs_cb cb;
 988        cb.all_revs = revs;
 989        cb.all_flags = flags;
 990        for_each_reflog(handle_one_reflog, &cb);
 991}
 992
 993static int add_parents_only(struct rev_info *revs, const char *arg_, int flags)
 994{
 995        unsigned char sha1[20];
 996        struct object *it;
 997        struct commit *commit;
 998        struct commit_list *parents;
 999        const char *arg = arg_;
1000
1001        if (*arg == '^') {
1002                flags ^= UNINTERESTING;
1003                arg++;
1004        }
1005        if (get_sha1_committish(arg, sha1))
1006                return 0;
1007        while (1) {
1008                it = get_reference(revs, arg, sha1, 0);
1009                if (!it && revs->ignore_missing)
1010                        return 0;
1011                if (it->type != OBJ_TAG)
1012                        break;
1013                if (!((struct tag*)it)->tagged)
1014                        return 0;
1015                hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
1016        }
1017        if (it->type != OBJ_COMMIT)
1018                return 0;
1019        commit = (struct commit *)it;
1020        for (parents = commit->parents; parents; parents = parents->next) {
1021                it = &parents->item->object;
1022                it->flags |= flags;
1023                add_rev_cmdline(revs, it, arg_, REV_CMD_PARENTS_ONLY, flags);
1024                add_pending_object(revs, it, arg);
1025        }
1026        return 1;
1027}
1028
1029void init_revisions(struct rev_info *revs, const char *prefix)
1030{
1031        memset(revs, 0, sizeof(*revs));
1032
1033        revs->abbrev = DEFAULT_ABBREV;
1034        revs->ignore_merges = 1;
1035        revs->simplify_history = 1;
1036        DIFF_OPT_SET(&revs->pruning, RECURSIVE);
1037        DIFF_OPT_SET(&revs->pruning, QUICK);
1038        revs->pruning.add_remove = file_add_remove;
1039        revs->pruning.change = file_change;
1040        revs->lifo = 1;
1041        revs->dense = 1;
1042        revs->prefix = prefix;
1043        revs->max_age = -1;
1044        revs->min_age = -1;
1045        revs->skip_count = -1;
1046        revs->max_count = -1;
1047        revs->max_parents = -1;
1048
1049        revs->commit_format = CMIT_FMT_DEFAULT;
1050
1051        revs->grep_filter.status_only = 1;
1052        revs->grep_filter.pattern_tail = &(revs->grep_filter.pattern_list);
1053        revs->grep_filter.header_tail = &(revs->grep_filter.header_list);
1054        revs->grep_filter.regflags = REG_NEWLINE;
1055
1056        diff_setup(&revs->diffopt);
1057        if (prefix && !revs->diffopt.prefix) {
1058                revs->diffopt.prefix = prefix;
1059                revs->diffopt.prefix_length = strlen(prefix);
1060        }
1061
1062        revs->notes_opt.use_default_notes = -1;
1063}
1064
1065static void add_pending_commit_list(struct rev_info *revs,
1066                                    struct commit_list *commit_list,
1067                                    unsigned int flags)
1068{
1069        while (commit_list) {
1070                struct object *object = &commit_list->item->object;
1071                object->flags |= flags;
1072                add_pending_object(revs, object, sha1_to_hex(object->sha1));
1073                commit_list = commit_list->next;
1074        }
1075}
1076
1077static void prepare_show_merge(struct rev_info *revs)
1078{
1079        struct commit_list *bases;
1080        struct commit *head, *other;
1081        unsigned char sha1[20];
1082        const char **prune = NULL;
1083        int i, prune_num = 1; /* counting terminating NULL */
1084
1085        if (get_sha1("HEAD", sha1))
1086                die("--merge without HEAD?");
1087        head = lookup_commit_or_die(sha1, "HEAD");
1088        if (get_sha1("MERGE_HEAD", sha1))
1089                die("--merge without MERGE_HEAD?");
1090        other = lookup_commit_or_die(sha1, "MERGE_HEAD");
1091        add_pending_object(revs, &head->object, "HEAD");
1092        add_pending_object(revs, &other->object, "MERGE_HEAD");
1093        bases = get_merge_bases(head, other, 1);
1094        add_pending_commit_list(revs, bases, UNINTERESTING);
1095        free_commit_list(bases);
1096        head->object.flags |= SYMMETRIC_LEFT;
1097
1098        if (!active_nr)
1099                read_cache();
1100        for (i = 0; i < active_nr; i++) {
1101                struct cache_entry *ce = active_cache[i];
1102                if (!ce_stage(ce))
1103                        continue;
1104                if (ce_path_match(ce, &revs->prune_data)) {
1105                        prune_num++;
1106                        prune = xrealloc(prune, sizeof(*prune) * prune_num);
1107                        prune[prune_num-2] = ce->name;
1108                        prune[prune_num-1] = NULL;
1109                }
1110                while ((i+1 < active_nr) &&
1111                       ce_same_name(ce, active_cache[i+1]))
1112                        i++;
1113        }
1114        free_pathspec(&revs->prune_data);
1115        init_pathspec(&revs->prune_data, prune);
1116        revs->limited = 1;
1117}
1118
1119int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsigned revarg_opt)
1120{
1121        struct object_context oc;
1122        char *dotdot;
1123        struct object *object;
1124        unsigned char sha1[20];
1125        int local_flags;
1126        const char *arg = arg_;
1127        int cant_be_filename = revarg_opt & REVARG_CANNOT_BE_FILENAME;
1128        unsigned get_sha1_flags = 0;
1129
1130        dotdot = strstr(arg, "..");
1131        if (dotdot) {
1132                unsigned char from_sha1[20];
1133                const char *next = dotdot + 2;
1134                const char *this = arg;
1135                int symmetric = *next == '.';
1136                unsigned int flags_exclude = flags ^ UNINTERESTING;
1137                unsigned int a_flags;
1138
1139                *dotdot = 0;
1140                next += symmetric;
1141
1142                if (!*next)
1143                        next = "HEAD";
1144                if (dotdot == arg)
1145                        this = "HEAD";
1146                if (!get_sha1_committish(this, from_sha1) &&
1147                    !get_sha1_committish(next, sha1)) {
1148                        struct commit *a, *b;
1149                        struct commit_list *exclude;
1150
1151                        a = lookup_commit_reference(from_sha1);
1152                        b = lookup_commit_reference(sha1);
1153                        if (!a || !b) {
1154                                if (revs->ignore_missing)
1155                                        return 0;
1156                                die(symmetric ?
1157                                    "Invalid symmetric difference expression %s...%s" :
1158                                    "Invalid revision range %s..%s",
1159                                    arg, next);
1160                        }
1161
1162                        if (!cant_be_filename) {
1163                                *dotdot = '.';
1164                                verify_non_filename(revs->prefix, arg);
1165                        }
1166
1167                        if (symmetric) {
1168                                exclude = get_merge_bases(a, b, 1);
1169                                add_pending_commit_list(revs, exclude,
1170                                                        flags_exclude);
1171                                free_commit_list(exclude);
1172                                a_flags = flags | SYMMETRIC_LEFT;
1173                        } else
1174                                a_flags = flags_exclude;
1175                        a->object.flags |= a_flags;
1176                        b->object.flags |= flags;
1177                        add_rev_cmdline(revs, &a->object, this,
1178                                        REV_CMD_LEFT, a_flags);
1179                        add_rev_cmdline(revs, &b->object, next,
1180                                        REV_CMD_RIGHT, flags);
1181                        add_pending_object(revs, &a->object, this);
1182                        add_pending_object(revs, &b->object, next);
1183                        return 0;
1184                }
1185                *dotdot = '.';
1186        }
1187        dotdot = strstr(arg, "^@");
1188        if (dotdot && !dotdot[2]) {
1189                *dotdot = 0;
1190                if (add_parents_only(revs, arg, flags))
1191                        return 0;
1192                *dotdot = '^';
1193        }
1194        dotdot = strstr(arg, "^!");
1195        if (dotdot && !dotdot[2]) {
1196                *dotdot = 0;
1197                if (!add_parents_only(revs, arg, flags ^ UNINTERESTING))
1198                        *dotdot = '^';
1199        }
1200
1201        local_flags = 0;
1202        if (*arg == '^') {
1203                local_flags = UNINTERESTING;
1204                arg++;
1205        }
1206
1207        if (revarg_opt & REVARG_COMMITTISH)
1208                get_sha1_flags = GET_SHA1_COMMITTISH;
1209
1210        if (get_sha1_with_context(arg, get_sha1_flags, sha1, &oc))
1211                return revs->ignore_missing ? 0 : -1;
1212        if (!cant_be_filename)
1213                verify_non_filename(revs->prefix, arg);
1214        object = get_reference(revs, arg, sha1, flags ^ local_flags);
1215        add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
1216        add_pending_object_with_mode(revs, object, arg, oc.mode);
1217        return 0;
1218}
1219
1220struct cmdline_pathspec {
1221        int alloc;
1222        int nr;
1223        const char **path;
1224};
1225
1226static void append_prune_data(struct cmdline_pathspec *prune, const char **av)
1227{
1228        while (*av) {
1229                ALLOC_GROW(prune->path, prune->nr+1, prune->alloc);
1230                prune->path[prune->nr++] = *(av++);
1231        }
1232}
1233
1234static void read_pathspec_from_stdin(struct rev_info *revs, struct strbuf *sb,
1235                                     struct cmdline_pathspec *prune)
1236{
1237        while (strbuf_getwholeline(sb, stdin, '\n') != EOF) {
1238                int len = sb->len;
1239                if (len && sb->buf[len - 1] == '\n')
1240                        sb->buf[--len] = '\0';
1241                ALLOC_GROW(prune->path, prune->nr+1, prune->alloc);
1242                prune->path[prune->nr++] = xstrdup(sb->buf);
1243        }
1244}
1245
1246static void read_revisions_from_stdin(struct rev_info *revs,
1247                                      struct cmdline_pathspec *prune)
1248{
1249        struct strbuf sb;
1250        int seen_dashdash = 0;
1251
1252        strbuf_init(&sb, 1000);
1253        while (strbuf_getwholeline(&sb, stdin, '\n') != EOF) {
1254                int len = sb.len;
1255                if (len && sb.buf[len - 1] == '\n')
1256                        sb.buf[--len] = '\0';
1257                if (!len)
1258                        break;
1259                if (sb.buf[0] == '-') {
1260                        if (len == 2 && sb.buf[1] == '-') {
1261                                seen_dashdash = 1;
1262                                break;
1263                        }
1264                        die("options not supported in --stdin mode");
1265                }
1266                if (handle_revision_arg(sb.buf, revs, 0, REVARG_CANNOT_BE_FILENAME))
1267                        die("bad revision '%s'", sb.buf);
1268        }
1269        if (seen_dashdash)
1270                read_pathspec_from_stdin(revs, &sb, prune);
1271        strbuf_release(&sb);
1272}
1273
1274static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
1275{
1276        append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
1277}
1278
1279static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
1280{
1281        append_header_grep_pattern(&revs->grep_filter, field, pattern);
1282}
1283
1284static void add_message_grep(struct rev_info *revs, const char *pattern)
1285{
1286        add_grep(revs, pattern, GREP_PATTERN_BODY);
1287}
1288
1289static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
1290                               int *unkc, const char **unkv)
1291{
1292        const char *arg = argv[0];
1293        const char *optarg;
1294        int argcount;
1295
1296        /* pseudo revision arguments */
1297        if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
1298            !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
1299            !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
1300            !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
1301            !strcmp(arg, "--bisect") || !prefixcmp(arg, "--glob=") ||
1302            !prefixcmp(arg, "--branches=") || !prefixcmp(arg, "--tags=") ||
1303            !prefixcmp(arg, "--remotes="))
1304        {
1305                unkv[(*unkc)++] = arg;
1306                return 1;
1307        }
1308
1309        if ((argcount = parse_long_opt("max-count", argv, &optarg))) {
1310                revs->max_count = atoi(optarg);
1311                revs->no_walk = 0;
1312                return argcount;
1313        } else if ((argcount = parse_long_opt("skip", argv, &optarg))) {
1314                revs->skip_count = atoi(optarg);
1315                return argcount;
1316        } else if ((*arg == '-') && isdigit(arg[1])) {
1317        /* accept -<digit>, like traditional "head" */
1318                revs->max_count = atoi(arg + 1);
1319                revs->no_walk = 0;
1320        } else if (!strcmp(arg, "-n")) {
1321                if (argc <= 1)
1322                        return error("-n requires an argument");
1323                revs->max_count = atoi(argv[1]);
1324                revs->no_walk = 0;
1325                return 2;
1326        } else if (!prefixcmp(arg, "-n")) {
1327                revs->max_count = atoi(arg + 2);
1328                revs->no_walk = 0;
1329        } else if ((argcount = parse_long_opt("max-age", argv, &optarg))) {
1330                revs->max_age = atoi(optarg);
1331                return argcount;
1332        } else if ((argcount = parse_long_opt("since", argv, &optarg))) {
1333                revs->max_age = approxidate(optarg);
1334                return argcount;
1335        } else if ((argcount = parse_long_opt("after", argv, &optarg))) {
1336                revs->max_age = approxidate(optarg);
1337                return argcount;
1338        } else if ((argcount = parse_long_opt("min-age", argv, &optarg))) {
1339                revs->min_age = atoi(optarg);
1340                return argcount;
1341        } else if ((argcount = parse_long_opt("before", argv, &optarg))) {
1342                revs->min_age = approxidate(optarg);
1343                return argcount;
1344        } else if ((argcount = parse_long_opt("until", argv, &optarg))) {
1345                revs->min_age = approxidate(optarg);
1346                return argcount;
1347        } else if (!strcmp(arg, "--first-parent")) {
1348                revs->first_parent_only = 1;
1349        } else if (!strcmp(arg, "--ancestry-path")) {
1350                revs->ancestry_path = 1;
1351                revs->simplify_history = 0;
1352                revs->limited = 1;
1353        } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
1354                init_reflog_walk(&revs->reflog_info);
1355        } else if (!strcmp(arg, "--default")) {
1356                if (argc <= 1)
1357                        return error("bad --default argument");
1358                revs->def = argv[1];
1359                return 2;
1360        } else if (!strcmp(arg, "--merge")) {
1361                revs->show_merge = 1;
1362        } else if (!strcmp(arg, "--topo-order")) {
1363                revs->lifo = 1;
1364                revs->topo_order = 1;
1365        } else if (!strcmp(arg, "--simplify-merges")) {
1366                revs->simplify_merges = 1;
1367                revs->topo_order = 1;
1368                revs->rewrite_parents = 1;
1369                revs->simplify_history = 0;
1370                revs->limited = 1;
1371        } else if (!strcmp(arg, "--simplify-by-decoration")) {
1372                revs->simplify_merges = 1;
1373                revs->topo_order = 1;
1374                revs->rewrite_parents = 1;
1375                revs->simplify_history = 0;
1376                revs->simplify_by_decoration = 1;
1377                revs->limited = 1;
1378                revs->prune = 1;
1379                load_ref_decorations(DECORATE_SHORT_REFS);
1380        } else if (!strcmp(arg, "--date-order")) {
1381                revs->lifo = 0;
1382                revs->topo_order = 1;
1383        } else if (!prefixcmp(arg, "--early-output")) {
1384                int count = 100;
1385                switch (arg[14]) {
1386                case '=':
1387                        count = atoi(arg+15);
1388                        /* Fallthrough */
1389                case 0:
1390                        revs->topo_order = 1;
1391                       revs->early_output = count;
1392                }
1393        } else if (!strcmp(arg, "--parents")) {
1394                revs->rewrite_parents = 1;
1395                revs->print_parents = 1;
1396        } else if (!strcmp(arg, "--dense")) {
1397                revs->dense = 1;
1398        } else if (!strcmp(arg, "--sparse")) {
1399                revs->dense = 0;
1400        } else if (!strcmp(arg, "--show-all")) {
1401                revs->show_all = 1;
1402        } else if (!strcmp(arg, "--remove-empty")) {
1403                revs->remove_empty_trees = 1;
1404        } else if (!strcmp(arg, "--merges")) {
1405                revs->min_parents = 2;
1406        } else if (!strcmp(arg, "--no-merges")) {
1407                revs->max_parents = 1;
1408        } else if (!prefixcmp(arg, "--min-parents=")) {
1409                revs->min_parents = atoi(arg+14);
1410        } else if (!prefixcmp(arg, "--no-min-parents")) {
1411                revs->min_parents = 0;
1412        } else if (!prefixcmp(arg, "--max-parents=")) {
1413                revs->max_parents = atoi(arg+14);
1414        } else if (!prefixcmp(arg, "--no-max-parents")) {
1415                revs->max_parents = -1;
1416        } else if (!strcmp(arg, "--boundary")) {
1417                revs->boundary = 1;
1418        } else if (!strcmp(arg, "--left-right")) {
1419                revs->left_right = 1;
1420        } else if (!strcmp(arg, "--left-only")) {
1421                if (revs->right_only)
1422                        die("--left-only is incompatible with --right-only"
1423                            " or --cherry");
1424                revs->left_only = 1;
1425        } else if (!strcmp(arg, "--right-only")) {
1426                if (revs->left_only)
1427                        die("--right-only is incompatible with --left-only");
1428                revs->right_only = 1;
1429        } else if (!strcmp(arg, "--cherry")) {
1430                if (revs->left_only)
1431                        die("--cherry is incompatible with --left-only");
1432                revs->cherry_mark = 1;
1433                revs->right_only = 1;
1434                revs->max_parents = 1;
1435                revs->limited = 1;
1436        } else if (!strcmp(arg, "--count")) {
1437                revs->count = 1;
1438        } else if (!strcmp(arg, "--cherry-mark")) {
1439                if (revs->cherry_pick)
1440                        die("--cherry-mark is incompatible with --cherry-pick");
1441                revs->cherry_mark = 1;
1442                revs->limited = 1; /* needs limit_list() */
1443        } else if (!strcmp(arg, "--cherry-pick")) {
1444                if (revs->cherry_mark)
1445                        die("--cherry-pick is incompatible with --cherry-mark");
1446                revs->cherry_pick = 1;
1447                revs->limited = 1;
1448        } else if (!strcmp(arg, "--objects")) {
1449                revs->tag_objects = 1;
1450                revs->tree_objects = 1;
1451                revs->blob_objects = 1;
1452        } else if (!strcmp(arg, "--objects-edge")) {
1453                revs->tag_objects = 1;
1454                revs->tree_objects = 1;
1455                revs->blob_objects = 1;
1456                revs->edge_hint = 1;
1457        } else if (!strcmp(arg, "--verify-objects")) {
1458                revs->tag_objects = 1;
1459                revs->tree_objects = 1;
1460                revs->blob_objects = 1;
1461                revs->verify_objects = 1;
1462        } else if (!strcmp(arg, "--unpacked")) {
1463                revs->unpacked = 1;
1464        } else if (!prefixcmp(arg, "--unpacked=")) {
1465                die("--unpacked=<packfile> no longer supported.");
1466        } else if (!strcmp(arg, "-r")) {
1467                revs->diff = 1;
1468                DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1469        } else if (!strcmp(arg, "-t")) {
1470                revs->diff = 1;
1471                DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1472                DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1473        } else if (!strcmp(arg, "-m")) {
1474                revs->ignore_merges = 0;
1475        } else if (!strcmp(arg, "-c")) {
1476                revs->diff = 1;
1477                revs->dense_combined_merges = 0;
1478                revs->combine_merges = 1;
1479        } else if (!strcmp(arg, "--cc")) {
1480                revs->diff = 1;
1481                revs->dense_combined_merges = 1;
1482                revs->combine_merges = 1;
1483        } else if (!strcmp(arg, "-v")) {
1484                revs->verbose_header = 1;
1485        } else if (!strcmp(arg, "--pretty")) {
1486                revs->verbose_header = 1;
1487                revs->pretty_given = 1;
1488                get_commit_format(arg+8, revs);
1489        } else if (!prefixcmp(arg, "--pretty=") || !prefixcmp(arg, "--format=")) {
1490                /*
1491                 * Detached form ("--pretty X" as opposed to "--pretty=X")
1492                 * not allowed, since the argument is optional.
1493                 */
1494                revs->verbose_header = 1;
1495                revs->pretty_given = 1;
1496                get_commit_format(arg+9, revs);
1497        } else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
1498                revs->show_notes = 1;
1499                revs->show_notes_given = 1;
1500                revs->notes_opt.use_default_notes = 1;
1501        } else if (!strcmp(arg, "--show-signature")) {
1502                revs->show_signature = 1;
1503        } else if (!prefixcmp(arg, "--show-notes=") ||
1504                   !prefixcmp(arg, "--notes=")) {
1505                struct strbuf buf = STRBUF_INIT;
1506                revs->show_notes = 1;
1507                revs->show_notes_given = 1;
1508                if (!prefixcmp(arg, "--show-notes")) {
1509                        if (revs->notes_opt.use_default_notes < 0)
1510                                revs->notes_opt.use_default_notes = 1;
1511                        strbuf_addstr(&buf, arg+13);
1512                }
1513                else
1514                        strbuf_addstr(&buf, arg+8);
1515                expand_notes_ref(&buf);
1516                string_list_append(&revs->notes_opt.extra_notes_refs,
1517                                   strbuf_detach(&buf, NULL));
1518        } else if (!strcmp(arg, "--no-notes")) {
1519                revs->show_notes = 0;
1520                revs->show_notes_given = 1;
1521                revs->notes_opt.use_default_notes = -1;
1522                /* we have been strdup'ing ourselves, so trick
1523                 * string_list into free()ing strings */
1524                revs->notes_opt.extra_notes_refs.strdup_strings = 1;
1525                string_list_clear(&revs->notes_opt.extra_notes_refs, 0);
1526                revs->notes_opt.extra_notes_refs.strdup_strings = 0;
1527        } else if (!strcmp(arg, "--standard-notes")) {
1528                revs->show_notes_given = 1;
1529                revs->notes_opt.use_default_notes = 1;
1530        } else if (!strcmp(arg, "--no-standard-notes")) {
1531                revs->notes_opt.use_default_notes = 0;
1532        } else if (!strcmp(arg, "--oneline")) {
1533                revs->verbose_header = 1;
1534                get_commit_format("oneline", revs);
1535                revs->pretty_given = 1;
1536                revs->abbrev_commit = 1;
1537        } else if (!strcmp(arg, "--graph")) {
1538                revs->topo_order = 1;
1539                revs->rewrite_parents = 1;
1540                revs->graph = graph_init(revs);
1541        } else if (!strcmp(arg, "--root")) {
1542                revs->show_root_diff = 1;
1543        } else if (!strcmp(arg, "--no-commit-id")) {
1544                revs->no_commit_id = 1;
1545        } else if (!strcmp(arg, "--always")) {
1546                revs->always_show_header = 1;
1547        } else if (!strcmp(arg, "--no-abbrev")) {
1548                revs->abbrev = 0;
1549        } else if (!strcmp(arg, "--abbrev")) {
1550                revs->abbrev = DEFAULT_ABBREV;
1551        } else if (!prefixcmp(arg, "--abbrev=")) {
1552                revs->abbrev = strtoul(arg + 9, NULL, 10);
1553                if (revs->abbrev < MINIMUM_ABBREV)
1554                        revs->abbrev = MINIMUM_ABBREV;
1555                else if (revs->abbrev > 40)
1556                        revs->abbrev = 40;
1557        } else if (!strcmp(arg, "--abbrev-commit")) {
1558                revs->abbrev_commit = 1;
1559                revs->abbrev_commit_given = 1;
1560        } else if (!strcmp(arg, "--no-abbrev-commit")) {
1561                revs->abbrev_commit = 0;
1562        } else if (!strcmp(arg, "--full-diff")) {
1563                revs->diff = 1;
1564                revs->full_diff = 1;
1565        } else if (!strcmp(arg, "--full-history")) {
1566                revs->simplify_history = 0;
1567        } else if (!strcmp(arg, "--relative-date")) {
1568                revs->date_mode = DATE_RELATIVE;
1569                revs->date_mode_explicit = 1;
1570        } else if ((argcount = parse_long_opt("date", argv, &optarg))) {
1571                revs->date_mode = parse_date_format(optarg);
1572                revs->date_mode_explicit = 1;
1573                return argcount;
1574        } else if (!strcmp(arg, "--log-size")) {
1575                revs->show_log_size = 1;
1576        }
1577        /*
1578         * Grepping the commit log
1579         */
1580        else if ((argcount = parse_long_opt("author", argv, &optarg))) {
1581                add_header_grep(revs, GREP_HEADER_AUTHOR, optarg);
1582                return argcount;
1583        } else if ((argcount = parse_long_opt("committer", argv, &optarg))) {
1584                add_header_grep(revs, GREP_HEADER_COMMITTER, optarg);
1585                return argcount;
1586        } else if ((argcount = parse_long_opt("grep", argv, &optarg))) {
1587                add_message_grep(revs, optarg);
1588                return argcount;
1589        } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
1590                revs->grep_filter.regflags |= REG_EXTENDED;
1591        } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
1592                revs->grep_filter.regflags |= REG_ICASE;
1593                DIFF_OPT_SET(&revs->diffopt, PICKAXE_IGNORE_CASE);
1594        } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
1595                revs->grep_filter.fixed = 1;
1596        } else if (!strcmp(arg, "--all-match")) {
1597                revs->grep_filter.all_match = 1;
1598        } else if ((argcount = parse_long_opt("encoding", argv, &optarg))) {
1599                if (strcmp(optarg, "none"))
1600                        git_log_output_encoding = xstrdup(optarg);
1601                else
1602                        git_log_output_encoding = "";
1603                return argcount;
1604        } else if (!strcmp(arg, "--reverse")) {
1605                revs->reverse ^= 1;
1606        } else if (!strcmp(arg, "--children")) {
1607                revs->children.name = "children";
1608                revs->limited = 1;
1609        } else if (!strcmp(arg, "--ignore-missing")) {
1610                revs->ignore_missing = 1;
1611        } else {
1612                int opts = diff_opt_parse(&revs->diffopt, argv, argc);
1613                if (!opts)
1614                        unkv[(*unkc)++] = arg;
1615                return opts;
1616        }
1617
1618        return 1;
1619}
1620
1621void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
1622                        const struct option *options,
1623                        const char * const usagestr[])
1624{
1625        int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
1626                                    &ctx->cpidx, ctx->out);
1627        if (n <= 0) {
1628                error("unknown option `%s'", ctx->argv[0]);
1629                usage_with_options(usagestr, options);
1630        }
1631        ctx->argv += n;
1632        ctx->argc -= n;
1633}
1634
1635static int for_each_bad_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1636{
1637        return for_each_ref_in_submodule(submodule, "refs/bisect/bad", fn, cb_data);
1638}
1639
1640static int for_each_good_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1641{
1642        return for_each_ref_in_submodule(submodule, "refs/bisect/good", fn, cb_data);
1643}
1644
1645static int handle_revision_pseudo_opt(const char *submodule,
1646                                struct rev_info *revs,
1647                                int argc, const char **argv, int *flags)
1648{
1649        const char *arg = argv[0];
1650        const char *optarg;
1651        int argcount;
1652
1653        /*
1654         * NOTE!
1655         *
1656         * Commands like "git shortlog" will not accept the options below
1657         * unless parse_revision_opt queues them (as opposed to erroring
1658         * out).
1659         *
1660         * When implementing your new pseudo-option, remember to
1661         * register it in the list at the top of handle_revision_opt.
1662         */
1663        if (!strcmp(arg, "--all")) {
1664                handle_refs(submodule, revs, *flags, for_each_ref_submodule);
1665                handle_refs(submodule, revs, *flags, head_ref_submodule);
1666        } else if (!strcmp(arg, "--branches")) {
1667                handle_refs(submodule, revs, *flags, for_each_branch_ref_submodule);
1668        } else if (!strcmp(arg, "--bisect")) {
1669                handle_refs(submodule, revs, *flags, for_each_bad_bisect_ref);
1670                handle_refs(submodule, revs, *flags ^ UNINTERESTING, for_each_good_bisect_ref);
1671                revs->bisect = 1;
1672        } else if (!strcmp(arg, "--tags")) {
1673                handle_refs(submodule, revs, *flags, for_each_tag_ref_submodule);
1674        } else if (!strcmp(arg, "--remotes")) {
1675                handle_refs(submodule, revs, *flags, for_each_remote_ref_submodule);
1676        } else if ((argcount = parse_long_opt("glob", argv, &optarg))) {
1677                struct all_refs_cb cb;
1678                init_all_refs_cb(&cb, revs, *flags);
1679                for_each_glob_ref(handle_one_ref, optarg, &cb);
1680                return argcount;
1681        } else if (!prefixcmp(arg, "--branches=")) {
1682                struct all_refs_cb cb;
1683                init_all_refs_cb(&cb, revs, *flags);
1684                for_each_glob_ref_in(handle_one_ref, arg + 11, "refs/heads/", &cb);
1685        } else if (!prefixcmp(arg, "--tags=")) {
1686                struct all_refs_cb cb;
1687                init_all_refs_cb(&cb, revs, *flags);
1688                for_each_glob_ref_in(handle_one_ref, arg + 7, "refs/tags/", &cb);
1689        } else if (!prefixcmp(arg, "--remotes=")) {
1690                struct all_refs_cb cb;
1691                init_all_refs_cb(&cb, revs, *flags);
1692                for_each_glob_ref_in(handle_one_ref, arg + 10, "refs/remotes/", &cb);
1693        } else if (!strcmp(arg, "--reflog")) {
1694                handle_reflog(revs, *flags);
1695        } else if (!strcmp(arg, "--not")) {
1696                *flags ^= UNINTERESTING;
1697        } else if (!strcmp(arg, "--no-walk")) {
1698                revs->no_walk = 1;
1699        } else if (!strcmp(arg, "--do-walk")) {
1700                revs->no_walk = 0;
1701        } else {
1702                return 0;
1703        }
1704
1705        return 1;
1706}
1707
1708/*
1709 * Parse revision information, filling in the "rev_info" structure,
1710 * and removing the used arguments from the argument list.
1711 *
1712 * Returns the number of arguments left that weren't recognized
1713 * (which are also moved to the head of the argument list)
1714 */
1715int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
1716{
1717        int i, flags, left, seen_dashdash, read_from_stdin, got_rev_arg = 0, revarg_opt;
1718        struct cmdline_pathspec prune_data;
1719        const char *submodule = NULL;
1720
1721        memset(&prune_data, 0, sizeof(prune_data));
1722        if (opt)
1723                submodule = opt->submodule;
1724
1725        /* First, search for "--" */
1726        if (opt && opt->assume_dashdash) {
1727                seen_dashdash = 1;
1728        } else {
1729                seen_dashdash = 0;
1730                for (i = 1; i < argc; i++) {
1731                        const char *arg = argv[i];
1732                        if (strcmp(arg, "--"))
1733                                continue;
1734                        argv[i] = NULL;
1735                        argc = i;
1736                        if (argv[i + 1])
1737                                append_prune_data(&prune_data, argv + i + 1);
1738                        seen_dashdash = 1;
1739                        break;
1740                }
1741        }
1742
1743        /* Second, deal with arguments and options */
1744        flags = 0;
1745        revarg_opt = opt ? opt->revarg_opt : 0;
1746        if (seen_dashdash)
1747                revarg_opt |= REVARG_CANNOT_BE_FILENAME;
1748        read_from_stdin = 0;
1749        for (left = i = 1; i < argc; i++) {
1750                const char *arg = argv[i];
1751                if (*arg == '-') {
1752                        int opts;
1753
1754                        opts = handle_revision_pseudo_opt(submodule,
1755                                                revs, argc - i, argv + i,
1756                                                &flags);
1757                        if (opts > 0) {
1758                                i += opts - 1;
1759                                continue;
1760                        }
1761
1762                        if (!strcmp(arg, "--stdin")) {
1763                                if (revs->disable_stdin) {
1764                                        argv[left++] = arg;
1765                                        continue;
1766                                }
1767                                if (read_from_stdin++)
1768                                        die("--stdin given twice?");
1769                                read_revisions_from_stdin(revs, &prune_data);
1770                                continue;
1771                        }
1772
1773                        opts = handle_revision_opt(revs, argc - i, argv + i, &left, argv);
1774                        if (opts > 0) {
1775                                i += opts - 1;
1776                                continue;
1777                        }
1778                        if (opts < 0)
1779                                exit(128);
1780                        continue;
1781                }
1782
1783
1784                if (handle_revision_arg(arg, revs, flags, revarg_opt)) {
1785                        int j;
1786                        if (seen_dashdash || *arg == '^')
1787                                die("bad revision '%s'", arg);
1788
1789                        /* If we didn't have a "--":
1790                         * (1) all filenames must exist;
1791                         * (2) all rev-args must not be interpretable
1792                         *     as a valid filename.
1793                         * but the latter we have checked in the main loop.
1794                         */
1795                        for (j = i; j < argc; j++)
1796                                verify_filename(revs->prefix, argv[j], j == i);
1797
1798                        append_prune_data(&prune_data, argv + i);
1799                        break;
1800                }
1801                else
1802                        got_rev_arg = 1;
1803        }
1804
1805        if (prune_data.nr) {
1806                /*
1807                 * If we need to introduce the magic "a lone ':' means no
1808                 * pathspec whatsoever", here is the place to do so.
1809                 *
1810                 * if (prune_data.nr == 1 && !strcmp(prune_data[0], ":")) {
1811                 *      prune_data.nr = 0;
1812                 *      prune_data.alloc = 0;
1813                 *      free(prune_data.path);
1814                 *      prune_data.path = NULL;
1815                 * } else {
1816                 *      terminate prune_data.alloc with NULL and
1817                 *      call init_pathspec() to set revs->prune_data here.
1818                 * }
1819                 */
1820                ALLOC_GROW(prune_data.path, prune_data.nr+1, prune_data.alloc);
1821                prune_data.path[prune_data.nr++] = NULL;
1822                init_pathspec(&revs->prune_data,
1823                              get_pathspec(revs->prefix, prune_data.path));
1824        }
1825
1826        if (revs->def == NULL)
1827                revs->def = opt ? opt->def : NULL;
1828        if (opt && opt->tweak)
1829                opt->tweak(revs, opt);
1830        if (revs->show_merge)
1831                prepare_show_merge(revs);
1832        if (revs->def && !revs->pending.nr && !got_rev_arg) {
1833                unsigned char sha1[20];
1834                struct object *object;
1835                struct object_context oc;
1836                if (get_sha1_with_context(revs->def, 0, sha1, &oc))
1837                        die("bad default revision '%s'", revs->def);
1838                object = get_reference(revs, revs->def, sha1, 0);
1839                add_pending_object_with_mode(revs, object, revs->def, oc.mode);
1840        }
1841
1842        /* Did the user ask for any diff output? Run the diff! */
1843        if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
1844                revs->diff = 1;
1845
1846        /* Pickaxe, diff-filter and rename following need diffs */
1847        if (revs->diffopt.pickaxe ||
1848            revs->diffopt.filter ||
1849            DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1850                revs->diff = 1;
1851
1852        if (revs->topo_order)
1853                revs->limited = 1;
1854
1855        if (revs->prune_data.nr) {
1856                diff_tree_setup_paths(revs->prune_data.raw, &revs->pruning);
1857                /* Can't prune commits with rename following: the paths change.. */
1858                if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
1859                        revs->prune = 1;
1860                if (!revs->full_diff)
1861                        diff_tree_setup_paths(revs->prune_data.raw, &revs->diffopt);
1862        }
1863        if (revs->combine_merges)
1864                revs->ignore_merges = 0;
1865        revs->diffopt.abbrev = revs->abbrev;
1866        diff_setup_done(&revs->diffopt);
1867
1868        compile_grep_patterns(&revs->grep_filter);
1869
1870        if (revs->reverse && revs->reflog_info)
1871                die("cannot combine --reverse with --walk-reflogs");
1872        if (revs->rewrite_parents && revs->children.name)
1873                die("cannot combine --parents and --children");
1874
1875        /*
1876         * Limitations on the graph functionality
1877         */
1878        if (revs->reverse && revs->graph)
1879                die("cannot combine --reverse with --graph");
1880
1881        if (revs->reflog_info && revs->graph)
1882                die("cannot combine --walk-reflogs with --graph");
1883
1884        return left;
1885}
1886
1887static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
1888{
1889        struct commit_list *l = xcalloc(1, sizeof(*l));
1890
1891        l->item = child;
1892        l->next = add_decoration(&revs->children, &parent->object, l);
1893}
1894
1895static int remove_duplicate_parents(struct commit *commit)
1896{
1897        struct commit_list **pp, *p;
1898        int surviving_parents;
1899
1900        /* Examine existing parents while marking ones we have seen... */
1901        pp = &commit->parents;
1902        while ((p = *pp) != NULL) {
1903                struct commit *parent = p->item;
1904                if (parent->object.flags & TMP_MARK) {
1905                        *pp = p->next;
1906                        continue;
1907                }
1908                parent->object.flags |= TMP_MARK;
1909                pp = &p->next;
1910        }
1911        /* count them while clearing the temporary mark */
1912        surviving_parents = 0;
1913        for (p = commit->parents; p; p = p->next) {
1914                p->item->object.flags &= ~TMP_MARK;
1915                surviving_parents++;
1916        }
1917        return surviving_parents;
1918}
1919
1920struct merge_simplify_state {
1921        struct commit *simplified;
1922};
1923
1924static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
1925{
1926        struct merge_simplify_state *st;
1927
1928        st = lookup_decoration(&revs->merge_simplification, &commit->object);
1929        if (!st) {
1930                st = xcalloc(1, sizeof(*st));
1931                add_decoration(&revs->merge_simplification, &commit->object, st);
1932        }
1933        return st;
1934}
1935
1936static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
1937{
1938        struct commit_list *p;
1939        struct merge_simplify_state *st, *pst;
1940        int cnt;
1941
1942        st = locate_simplify_state(revs, commit);
1943
1944        /*
1945         * Have we handled this one?
1946         */
1947        if (st->simplified)
1948                return tail;
1949
1950        /*
1951         * An UNINTERESTING commit simplifies to itself, so does a
1952         * root commit.  We do not rewrite parents of such commit
1953         * anyway.
1954         */
1955        if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
1956                st->simplified = commit;
1957                return tail;
1958        }
1959
1960        /*
1961         * Do we know what commit all of our parents that matter
1962         * should be rewritten to?  Otherwise we are not ready to
1963         * rewrite this one yet.
1964         */
1965        for (cnt = 0, p = commit->parents; p; p = p->next) {
1966                pst = locate_simplify_state(revs, p->item);
1967                if (!pst->simplified) {
1968                        tail = &commit_list_insert(p->item, tail)->next;
1969                        cnt++;
1970                }
1971                if (revs->first_parent_only)
1972                        break;
1973        }
1974        if (cnt) {
1975                tail = &commit_list_insert(commit, tail)->next;
1976                return tail;
1977        }
1978
1979        /*
1980         * Rewrite our list of parents.
1981         */
1982        for (p = commit->parents; p; p = p->next) {
1983                pst = locate_simplify_state(revs, p->item);
1984                p->item = pst->simplified;
1985                if (revs->first_parent_only)
1986                        break;
1987        }
1988        if (!revs->first_parent_only)
1989                cnt = remove_duplicate_parents(commit);
1990        else
1991                cnt = 1;
1992
1993        /*
1994         * It is possible that we are a merge and one side branch
1995         * does not have any commit that touches the given paths;
1996         * in such a case, the immediate parents will be rewritten
1997         * to different commits.
1998         *
1999         *      o----X          X: the commit we are looking at;
2000         *     /    /           o: a commit that touches the paths;
2001         * ---o----'
2002         *
2003         * Further reduce the parents by removing redundant parents.
2004         */
2005        if (1 < cnt) {
2006                struct commit_list *h = reduce_heads(commit->parents);
2007                cnt = commit_list_count(h);
2008                free_commit_list(commit->parents);
2009                commit->parents = h;
2010        }
2011
2012        /*
2013         * A commit simplifies to itself if it is a root, if it is
2014         * UNINTERESTING, if it touches the given paths, or if it is a
2015         * merge and its parents simplifies to more than one commits
2016         * (the first two cases are already handled at the beginning of
2017         * this function).
2018         *
2019         * Otherwise, it simplifies to what its sole parent simplifies to.
2020         */
2021        if (!cnt ||
2022            (commit->object.flags & UNINTERESTING) ||
2023            !(commit->object.flags & TREESAME) ||
2024            (1 < cnt))
2025                st->simplified = commit;
2026        else {
2027                pst = locate_simplify_state(revs, commit->parents->item);
2028                st->simplified = pst->simplified;
2029        }
2030        return tail;
2031}
2032
2033static void simplify_merges(struct rev_info *revs)
2034{
2035        struct commit_list *list, *next;
2036        struct commit_list *yet_to_do, **tail;
2037        struct commit *commit;
2038
2039        if (!revs->prune)
2040                return;
2041
2042        /* feed the list reversed */
2043        yet_to_do = NULL;
2044        for (list = revs->commits; list; list = next) {
2045                commit = list->item;
2046                next = list->next;
2047                /*
2048                 * Do not free(list) here yet; the original list
2049                 * is used later in this function.
2050                 */
2051                commit_list_insert(commit, &yet_to_do);
2052        }
2053        while (yet_to_do) {
2054                list = yet_to_do;
2055                yet_to_do = NULL;
2056                tail = &yet_to_do;
2057                while (list) {
2058                        commit = list->item;
2059                        next = list->next;
2060                        free(list);
2061                        list = next;
2062                        tail = simplify_one(revs, commit, tail);
2063                }
2064        }
2065
2066        /* clean up the result, removing the simplified ones */
2067        list = revs->commits;
2068        revs->commits = NULL;
2069        tail = &revs->commits;
2070        while (list) {
2071                struct merge_simplify_state *st;
2072
2073                commit = list->item;
2074                next = list->next;
2075                free(list);
2076                list = next;
2077                st = locate_simplify_state(revs, commit);
2078                if (st->simplified == commit)
2079                        tail = &commit_list_insert(commit, tail)->next;
2080        }
2081}
2082
2083static void set_children(struct rev_info *revs)
2084{
2085        struct commit_list *l;
2086        for (l = revs->commits; l; l = l->next) {
2087                struct commit *commit = l->item;
2088                struct commit_list *p;
2089
2090                for (p = commit->parents; p; p = p->next)
2091                        add_child(revs, p->item, commit);
2092        }
2093}
2094
2095void reset_revision_walk(void)
2096{
2097        clear_object_flags(SEEN | ADDED | SHOWN);
2098}
2099
2100int prepare_revision_walk(struct rev_info *revs)
2101{
2102        int nr = revs->pending.nr;
2103        struct object_array_entry *e, *list;
2104        struct commit_list **next = &revs->commits;
2105
2106        e = list = revs->pending.objects;
2107        revs->pending.nr = 0;
2108        revs->pending.alloc = 0;
2109        revs->pending.objects = NULL;
2110        while (--nr >= 0) {
2111                struct commit *commit = handle_commit(revs, e->item, e->name);
2112                if (commit) {
2113                        if (!(commit->object.flags & SEEN)) {
2114                                commit->object.flags |= SEEN;
2115                                next = commit_list_append(commit, next);
2116                        }
2117                }
2118                e++;
2119        }
2120        commit_list_sort_by_date(&revs->commits);
2121        if (!revs->leak_pending)
2122                free(list);
2123
2124        if (revs->no_walk)
2125                return 0;
2126        if (revs->limited)
2127                if (limit_list(revs) < 0)
2128                        return -1;
2129        if (revs->topo_order)
2130                sort_in_topological_order(&revs->commits, revs->lifo);
2131        if (revs->simplify_merges)
2132                simplify_merges(revs);
2133        if (revs->children.name)
2134                set_children(revs);
2135        return 0;
2136}
2137
2138enum rewrite_result {
2139        rewrite_one_ok,
2140        rewrite_one_noparents,
2141        rewrite_one_error
2142};
2143
2144static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
2145{
2146        struct commit_list *cache = NULL;
2147
2148        for (;;) {
2149                struct commit *p = *pp;
2150                if (!revs->limited)
2151                        if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0)
2152                                return rewrite_one_error;
2153                if (p->parents && p->parents->next)
2154                        return rewrite_one_ok;
2155                if (p->object.flags & UNINTERESTING)
2156                        return rewrite_one_ok;
2157                if (!(p->object.flags & TREESAME))
2158                        return rewrite_one_ok;
2159                if (!p->parents)
2160                        return rewrite_one_noparents;
2161                *pp = p->parents->item;
2162        }
2163}
2164
2165static int rewrite_parents(struct rev_info *revs, struct commit *commit)
2166{
2167        struct commit_list **pp = &commit->parents;
2168        while (*pp) {
2169                struct commit_list *parent = *pp;
2170                switch (rewrite_one(revs, &parent->item)) {
2171                case rewrite_one_ok:
2172                        break;
2173                case rewrite_one_noparents:
2174                        *pp = parent->next;
2175                        continue;
2176                case rewrite_one_error:
2177                        return -1;
2178                }
2179                pp = &parent->next;
2180        }
2181        remove_duplicate_parents(commit);
2182        return 0;
2183}
2184
2185static int commit_match(struct commit *commit, struct rev_info *opt)
2186{
2187        if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
2188                return 1;
2189        return grep_buffer(&opt->grep_filter,
2190                           commit->buffer, strlen(commit->buffer));
2191}
2192
2193static inline int want_ancestry(struct rev_info *revs)
2194{
2195        return (revs->rewrite_parents || revs->children.name);
2196}
2197
2198enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
2199{
2200        if (commit->object.flags & SHOWN)
2201                return commit_ignore;
2202        if (revs->unpacked && has_sha1_pack(commit->object.sha1))
2203                return commit_ignore;
2204        if (revs->show_all)
2205                return commit_show;
2206        if (commit->object.flags & UNINTERESTING)
2207                return commit_ignore;
2208        if (revs->min_age != -1 && (commit->date > revs->min_age))
2209                return commit_ignore;
2210        if (revs->min_parents || (revs->max_parents >= 0)) {
2211                int n = 0;
2212                struct commit_list *p;
2213                for (p = commit->parents; p; p = p->next)
2214                        n++;
2215                if ((n < revs->min_parents) ||
2216                    ((revs->max_parents >= 0) && (n > revs->max_parents)))
2217                        return commit_ignore;
2218        }
2219        if (!commit_match(commit, revs))
2220                return commit_ignore;
2221        if (revs->prune && revs->dense) {
2222                /* Commit without changes? */
2223                if (commit->object.flags & TREESAME) {
2224                        /* drop merges unless we want parenthood */
2225                        if (!want_ancestry(revs))
2226                                return commit_ignore;
2227                        /* non-merge - always ignore it */
2228                        if (!commit->parents || !commit->parents->next)
2229                                return commit_ignore;
2230                }
2231        }
2232        return commit_show;
2233}
2234
2235enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
2236{
2237        enum commit_action action = get_commit_action(revs, commit);
2238
2239        if (action == commit_show &&
2240            !revs->show_all &&
2241            revs->prune && revs->dense && want_ancestry(revs)) {
2242                if (rewrite_parents(revs, commit) < 0)
2243                        return commit_error;
2244        }
2245        return action;
2246}
2247
2248static struct commit *get_revision_1(struct rev_info *revs)
2249{
2250        if (!revs->commits)
2251                return NULL;
2252
2253        do {
2254                struct commit_list *entry = revs->commits;
2255                struct commit *commit = entry->item;
2256
2257                revs->commits = entry->next;
2258                free(entry);
2259
2260                if (revs->reflog_info) {
2261                        fake_reflog_parent(revs->reflog_info, commit);
2262                        commit->object.flags &= ~(ADDED | SEEN | SHOWN);
2263                }
2264
2265                /*
2266                 * If we haven't done the list limiting, we need to look at
2267                 * the parents here. We also need to do the date-based limiting
2268                 * that we'd otherwise have done in limit_list().
2269                 */
2270                if (!revs->limited) {
2271                        if (revs->max_age != -1 &&
2272                            (commit->date < revs->max_age))
2273                                continue;
2274                        if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0)
2275                                die("Failed to traverse parents of commit %s",
2276                                    sha1_to_hex(commit->object.sha1));
2277                }
2278
2279                switch (simplify_commit(revs, commit)) {
2280                case commit_ignore:
2281                        continue;
2282                case commit_error:
2283                        die("Failed to simplify parents of commit %s",
2284                            sha1_to_hex(commit->object.sha1));
2285                default:
2286                        return commit;
2287                }
2288        } while (revs->commits);
2289        return NULL;
2290}
2291
2292static void gc_boundary(struct object_array *array)
2293{
2294        unsigned nr = array->nr;
2295        unsigned alloc = array->alloc;
2296        struct object_array_entry *objects = array->objects;
2297
2298        if (alloc <= nr) {
2299                unsigned i, j;
2300                for (i = j = 0; i < nr; i++) {
2301                        if (objects[i].item->flags & SHOWN)
2302                                continue;
2303                        if (i != j)
2304                                objects[j] = objects[i];
2305                        j++;
2306                }
2307                for (i = j; i < nr; i++)
2308                        objects[i].item = NULL;
2309                array->nr = j;
2310        }
2311}
2312
2313static void create_boundary_commit_list(struct rev_info *revs)
2314{
2315        unsigned i;
2316        struct commit *c;
2317        struct object_array *array = &revs->boundary_commits;
2318        struct object_array_entry *objects = array->objects;
2319
2320        /*
2321         * If revs->commits is non-NULL at this point, an error occurred in
2322         * get_revision_1().  Ignore the error and continue printing the
2323         * boundary commits anyway.  (This is what the code has always
2324         * done.)
2325         */
2326        if (revs->commits) {
2327                free_commit_list(revs->commits);
2328                revs->commits = NULL;
2329        }
2330
2331        /*
2332         * Put all of the actual boundary commits from revs->boundary_commits
2333         * into revs->commits
2334         */
2335        for (i = 0; i < array->nr; i++) {
2336                c = (struct commit *)(objects[i].item);
2337                if (!c)
2338                        continue;
2339                if (!(c->object.flags & CHILD_SHOWN))
2340                        continue;
2341                if (c->object.flags & (SHOWN | BOUNDARY))
2342                        continue;
2343                c->object.flags |= BOUNDARY;
2344                commit_list_insert(c, &revs->commits);
2345        }
2346
2347        /*
2348         * If revs->topo_order is set, sort the boundary commits
2349         * in topological order
2350         */
2351        sort_in_topological_order(&revs->commits, revs->lifo);
2352}
2353
2354static struct commit *get_revision_internal(struct rev_info *revs)
2355{
2356        struct commit *c = NULL;
2357        struct commit_list *l;
2358
2359        if (revs->boundary == 2) {
2360                /*
2361                 * All of the normal commits have already been returned,
2362                 * and we are now returning boundary commits.
2363                 * create_boundary_commit_list() has populated
2364                 * revs->commits with the remaining commits to return.
2365                 */
2366                c = pop_commit(&revs->commits);
2367                if (c)
2368                        c->object.flags |= SHOWN;
2369                return c;
2370        }
2371
2372        /*
2373         * If our max_count counter has reached zero, then we are done. We
2374         * don't simply return NULL because we still might need to show
2375         * boundary commits. But we want to avoid calling get_revision_1, which
2376         * might do a considerable amount of work finding the next commit only
2377         * for us to throw it away.
2378         *
2379         * If it is non-zero, then either we don't have a max_count at all
2380         * (-1), or it is still counting, in which case we decrement.
2381         */
2382        if (revs->max_count) {
2383                c = get_revision_1(revs);
2384                if (c) {
2385                        while (0 < revs->skip_count) {
2386                                revs->skip_count--;
2387                                c = get_revision_1(revs);
2388                                if (!c)
2389                                        break;
2390                        }
2391                }
2392
2393                if (revs->max_count > 0)
2394                        revs->max_count--;
2395        }
2396
2397        if (c)
2398                c->object.flags |= SHOWN;
2399
2400        if (!revs->boundary) {
2401                return c;
2402        }
2403
2404        if (!c) {
2405                /*
2406                 * get_revision_1() runs out the commits, and
2407                 * we are done computing the boundaries.
2408                 * switch to boundary commits output mode.
2409                 */
2410                revs->boundary = 2;
2411
2412                /*
2413                 * Update revs->commits to contain the list of
2414                 * boundary commits.
2415                 */
2416                create_boundary_commit_list(revs);
2417
2418                return get_revision_internal(revs);
2419        }
2420
2421        /*
2422         * boundary commits are the commits that are parents of the
2423         * ones we got from get_revision_1() but they themselves are
2424         * not returned from get_revision_1().  Before returning
2425         * 'c', we need to mark its parents that they could be boundaries.
2426         */
2427
2428        for (l = c->parents; l; l = l->next) {
2429                struct object *p;
2430                p = &(l->item->object);
2431                if (p->flags & (CHILD_SHOWN | SHOWN))
2432                        continue;
2433                p->flags |= CHILD_SHOWN;
2434                gc_boundary(&revs->boundary_commits);
2435                add_object_array(p, NULL, &revs->boundary_commits);
2436        }
2437
2438        return c;
2439}
2440
2441struct commit *get_revision(struct rev_info *revs)
2442{
2443        struct commit *c;
2444        struct commit_list *reversed;
2445
2446        if (revs->reverse) {
2447                reversed = NULL;
2448                while ((c = get_revision_internal(revs))) {
2449                        commit_list_insert(c, &reversed);
2450                }
2451                revs->commits = reversed;
2452                revs->reverse = 0;
2453                revs->reverse_output_stage = 1;
2454        }
2455
2456        if (revs->reverse_output_stage)
2457                return pop_commit(&revs->commits);
2458
2459        c = get_revision_internal(revs);
2460        if (c && revs->graph)
2461                graph_update(revs->graph, c);
2462        return c;
2463}
2464
2465char *get_revision_mark(const struct rev_info *revs, const struct commit *commit)
2466{
2467        if (commit->object.flags & BOUNDARY)
2468                return "-";
2469        else if (commit->object.flags & UNINTERESTING)
2470                return "^";
2471        else if (commit->object.flags & PATCHSAME)
2472                return "=";
2473        else if (!revs || revs->left_right) {
2474                if (commit->object.flags & SYMMETRIC_LEFT)
2475                        return "<";
2476                else
2477                        return ">";
2478        } else if (revs->graph)
2479                return "*";
2480        else if (revs->cherry_mark)
2481                return "+";
2482        return "";
2483}
2484
2485void put_revision_mark(const struct rev_info *revs, const struct commit *commit)
2486{
2487        char *mark = get_revision_mark(revs, commit);
2488        if (!strlen(mark))
2489                return;
2490        fputs(mark, stdout);
2491        putchar(' ');
2492}