revision.con commit Merge branch 'ds/commit-graph-incremental' (203cf46)
   1#include "cache.h"
   2#include "object-store.h"
   3#include "tag.h"
   4#include "blob.h"
   5#include "tree.h"
   6#include "commit.h"
   7#include "diff.h"
   8#include "refs.h"
   9#include "revision.h"
  10#include "repository.h"
  11#include "graph.h"
  12#include "grep.h"
  13#include "reflog-walk.h"
  14#include "patch-ids.h"
  15#include "decorate.h"
  16#include "log-tree.h"
  17#include "string-list.h"
  18#include "line-log.h"
  19#include "mailmap.h"
  20#include "commit-slab.h"
  21#include "dir.h"
  22#include "cache-tree.h"
  23#include "bisect.h"
  24#include "packfile.h"
  25#include "worktree.h"
  26#include "argv-array.h"
  27#include "commit-reach.h"
  28#include "commit-graph.h"
  29#include "prio-queue.h"
  30#include "hashmap.h"
  31
  32volatile show_early_output_fn_t show_early_output;
  33
  34static const char *term_bad;
  35static const char *term_good;
  36
  37implement_shared_commit_slab(revision_sources, char *);
  38
  39void show_object_with_name(FILE *out, struct object *obj, const char *name)
  40{
  41        const char *p;
  42
  43        fprintf(out, "%s ", oid_to_hex(&obj->oid));
  44        for (p = name; *p && *p != '\n'; p++)
  45                fputc(*p, out);
  46        fputc('\n', out);
  47}
  48
  49static void mark_blob_uninteresting(struct blob *blob)
  50{
  51        if (!blob)
  52                return;
  53        if (blob->object.flags & UNINTERESTING)
  54                return;
  55        blob->object.flags |= UNINTERESTING;
  56}
  57
  58static void mark_tree_contents_uninteresting(struct repository *r,
  59                                             struct tree *tree)
  60{
  61        struct tree_desc desc;
  62        struct name_entry entry;
  63
  64        if (parse_tree_gently(tree, 1) < 0)
  65                return;
  66
  67        init_tree_desc(&desc, tree->buffer, tree->size);
  68        while (tree_entry(&desc, &entry)) {
  69                switch (object_type(entry.mode)) {
  70                case OBJ_TREE:
  71                        mark_tree_uninteresting(r, lookup_tree(r, &entry.oid));
  72                        break;
  73                case OBJ_BLOB:
  74                        mark_blob_uninteresting(lookup_blob(r, &entry.oid));
  75                        break;
  76                default:
  77                        /* Subproject commit - not in this repository */
  78                        break;
  79                }
  80        }
  81
  82        /*
  83         * We don't care about the tree any more
  84         * after it has been marked uninteresting.
  85         */
  86        free_tree_buffer(tree);
  87}
  88
  89void mark_tree_uninteresting(struct repository *r, struct tree *tree)
  90{
  91        struct object *obj;
  92
  93        if (!tree)
  94                return;
  95
  96        obj = &tree->object;
  97        if (obj->flags & UNINTERESTING)
  98                return;
  99        obj->flags |= UNINTERESTING;
 100        mark_tree_contents_uninteresting(r, tree);
 101}
 102
 103struct path_and_oids_entry {
 104        struct hashmap_entry ent;
 105        char *path;
 106        struct oidset trees;
 107};
 108
 109static int path_and_oids_cmp(const void *hashmap_cmp_fn_data,
 110                             const struct path_and_oids_entry *e1,
 111                             const struct path_and_oids_entry *e2,
 112                             const void *keydata)
 113{
 114        return strcmp(e1->path, e2->path);
 115}
 116
 117static void paths_and_oids_init(struct hashmap *map)
 118{
 119        hashmap_init(map, (hashmap_cmp_fn) path_and_oids_cmp, NULL, 0);
 120}
 121
 122static void paths_and_oids_clear(struct hashmap *map)
 123{
 124        struct hashmap_iter iter;
 125        struct path_and_oids_entry *entry;
 126        hashmap_iter_init(map, &iter);
 127
 128        while ((entry = (struct path_and_oids_entry *)hashmap_iter_next(&iter))) {
 129                oidset_clear(&entry->trees);
 130                free(entry->path);
 131        }
 132
 133        hashmap_free(map, 1);
 134}
 135
 136static void paths_and_oids_insert(struct hashmap *map,
 137                                  const char *path,
 138                                  const struct object_id *oid)
 139{
 140        int hash = strhash(path);
 141        struct path_and_oids_entry key;
 142        struct path_and_oids_entry *entry;
 143
 144        hashmap_entry_init(&key, hash);
 145
 146        /* use a shallow copy for the lookup */
 147        key.path = (char *)path;
 148        oidset_init(&key.trees, 0);
 149
 150        if (!(entry = (struct path_and_oids_entry *)hashmap_get(map, &key, NULL))) {
 151                entry = xcalloc(1, sizeof(struct path_and_oids_entry));
 152                hashmap_entry_init(entry, hash);
 153                entry->path = xstrdup(key.path);
 154                oidset_init(&entry->trees, 16);
 155                hashmap_put(map, entry);
 156        }
 157
 158        oidset_insert(&entry->trees, oid);
 159}
 160
 161static void add_children_by_path(struct repository *r,
 162                                 struct tree *tree,
 163                                 struct hashmap *map)
 164{
 165        struct tree_desc desc;
 166        struct name_entry entry;
 167
 168        if (!tree)
 169                return;
 170
 171        if (parse_tree_gently(tree, 1) < 0)
 172                return;
 173
 174        init_tree_desc(&desc, tree->buffer, tree->size);
 175        while (tree_entry(&desc, &entry)) {
 176                switch (object_type(entry.mode)) {
 177                case OBJ_TREE:
 178                        paths_and_oids_insert(map, entry.path, &entry.oid);
 179
 180                        if (tree->object.flags & UNINTERESTING) {
 181                                struct tree *child = lookup_tree(r, &entry.oid);
 182                                if (child)
 183                                        child->object.flags |= UNINTERESTING;
 184                        }
 185                        break;
 186                case OBJ_BLOB:
 187                        if (tree->object.flags & UNINTERESTING) {
 188                                struct blob *child = lookup_blob(r, &entry.oid);
 189                                if (child)
 190                                        child->object.flags |= UNINTERESTING;
 191                        }
 192                        break;
 193                default:
 194                        /* Subproject commit - not in this repository */
 195                        break;
 196                }
 197        }
 198
 199        free_tree_buffer(tree);
 200}
 201
 202void mark_trees_uninteresting_sparse(struct repository *r,
 203                                     struct oidset *trees)
 204{
 205        unsigned has_interesting = 0, has_uninteresting = 0;
 206        struct hashmap map;
 207        struct hashmap_iter map_iter;
 208        struct path_and_oids_entry *entry;
 209        struct object_id *oid;
 210        struct oidset_iter iter;
 211
 212        oidset_iter_init(trees, &iter);
 213        while ((!has_interesting || !has_uninteresting) &&
 214               (oid = oidset_iter_next(&iter))) {
 215                struct tree *tree = lookup_tree(r, oid);
 216
 217                if (!tree)
 218                        continue;
 219
 220                if (tree->object.flags & UNINTERESTING)
 221                        has_uninteresting = 1;
 222                else
 223                        has_interesting = 1;
 224        }
 225
 226        /* Do not walk unless we have both types of trees. */
 227        if (!has_uninteresting || !has_interesting)
 228                return;
 229
 230        paths_and_oids_init(&map);
 231
 232        oidset_iter_init(trees, &iter);
 233        while ((oid = oidset_iter_next(&iter))) {
 234                struct tree *tree = lookup_tree(r, oid);
 235                add_children_by_path(r, tree, &map);
 236        }
 237
 238        hashmap_iter_init(&map, &map_iter);
 239        while ((entry = hashmap_iter_next(&map_iter)))
 240                mark_trees_uninteresting_sparse(r, &entry->trees);
 241
 242        paths_and_oids_clear(&map);
 243}
 244
 245struct commit_stack {
 246        struct commit **items;
 247        size_t nr, alloc;
 248};
 249#define COMMIT_STACK_INIT { NULL, 0, 0 }
 250
 251static void commit_stack_push(struct commit_stack *stack, struct commit *commit)
 252{
 253        ALLOC_GROW(stack->items, stack->nr + 1, stack->alloc);
 254        stack->items[stack->nr++] = commit;
 255}
 256
 257static struct commit *commit_stack_pop(struct commit_stack *stack)
 258{
 259        return stack->nr ? stack->items[--stack->nr] : NULL;
 260}
 261
 262static void commit_stack_clear(struct commit_stack *stack)
 263{
 264        FREE_AND_NULL(stack->items);
 265        stack->nr = stack->alloc = 0;
 266}
 267
 268static void mark_one_parent_uninteresting(struct commit *commit,
 269                                          struct commit_stack *pending)
 270{
 271        struct commit_list *l;
 272
 273        if (commit->object.flags & UNINTERESTING)
 274                return;
 275        commit->object.flags |= UNINTERESTING;
 276
 277        /*
 278         * Normally we haven't parsed the parent
 279         * yet, so we won't have a parent of a parent
 280         * here. However, it may turn out that we've
 281         * reached this commit some other way (where it
 282         * wasn't uninteresting), in which case we need
 283         * to mark its parents recursively too..
 284         */
 285        for (l = commit->parents; l; l = l->next)
 286                commit_stack_push(pending, l->item);
 287}
 288
 289void mark_parents_uninteresting(struct commit *commit)
 290{
 291        struct commit_stack pending = COMMIT_STACK_INIT;
 292        struct commit_list *l;
 293
 294        for (l = commit->parents; l; l = l->next)
 295                mark_one_parent_uninteresting(l->item, &pending);
 296
 297        while (pending.nr > 0)
 298                mark_one_parent_uninteresting(commit_stack_pop(&pending),
 299                                              &pending);
 300
 301        commit_stack_clear(&pending);
 302}
 303
 304static void add_pending_object_with_path(struct rev_info *revs,
 305                                         struct object *obj,
 306                                         const char *name, unsigned mode,
 307                                         const char *path)
 308{
 309        if (!obj)
 310                return;
 311        if (revs->no_walk && (obj->flags & UNINTERESTING))
 312                revs->no_walk = 0;
 313        if (revs->reflog_info && obj->type == OBJ_COMMIT) {
 314                struct strbuf buf = STRBUF_INIT;
 315                int len = interpret_branch_name(name, 0, &buf, 0);
 316
 317                if (0 < len && name[len] && buf.len)
 318                        strbuf_addstr(&buf, name + len);
 319                add_reflog_for_walk(revs->reflog_info,
 320                                    (struct commit *)obj,
 321                                    buf.buf[0] ? buf.buf: name);
 322                strbuf_release(&buf);
 323                return; /* do not add the commit itself */
 324        }
 325        add_object_array_with_path(obj, name, &revs->pending, mode, path);
 326}
 327
 328static void add_pending_object_with_mode(struct rev_info *revs,
 329                                         struct object *obj,
 330                                         const char *name, unsigned mode)
 331{
 332        add_pending_object_with_path(revs, obj, name, mode, NULL);
 333}
 334
 335void add_pending_object(struct rev_info *revs,
 336                        struct object *obj, const char *name)
 337{
 338        add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
 339}
 340
 341void add_head_to_pending(struct rev_info *revs)
 342{
 343        struct object_id oid;
 344        struct object *obj;
 345        if (get_oid("HEAD", &oid))
 346                return;
 347        obj = parse_object(revs->repo, &oid);
 348        if (!obj)
 349                return;
 350        add_pending_object(revs, obj, "HEAD");
 351}
 352
 353static struct object *get_reference(struct rev_info *revs, const char *name,
 354                                    const struct object_id *oid,
 355                                    unsigned int flags)
 356{
 357        struct object *object;
 358
 359        /*
 360         * If the repository has commit graphs, repo_parse_commit() avoids
 361         * reading the object buffer, so use it whenever possible.
 362         */
 363        if (oid_object_info(revs->repo, oid, NULL) == OBJ_COMMIT) {
 364                struct commit *c = lookup_commit(revs->repo, oid);
 365                if (!repo_parse_commit(revs->repo, c))
 366                        object = (struct object *) c;
 367                else
 368                        object = NULL;
 369        } else {
 370                object = parse_object(revs->repo, oid);
 371        }
 372
 373        if (!object) {
 374                if (revs->ignore_missing)
 375                        return object;
 376                if (revs->exclude_promisor_objects && is_promisor_object(oid))
 377                        return NULL;
 378                die("bad object %s", name);
 379        }
 380        object->flags |= flags;
 381        return object;
 382}
 383
 384void add_pending_oid(struct rev_info *revs, const char *name,
 385                      const struct object_id *oid, unsigned int flags)
 386{
 387        struct object *object = get_reference(revs, name, oid, flags);
 388        add_pending_object(revs, object, name);
 389}
 390
 391static struct commit *handle_commit(struct rev_info *revs,
 392                                    struct object_array_entry *entry)
 393{
 394        struct object *object = entry->item;
 395        const char *name = entry->name;
 396        const char *path = entry->path;
 397        unsigned int mode = entry->mode;
 398        unsigned long flags = object->flags;
 399
 400        /*
 401         * Tag object? Look what it points to..
 402         */
 403        while (object->type == OBJ_TAG) {
 404                struct tag *tag = (struct tag *) object;
 405                if (revs->tag_objects && !(flags & UNINTERESTING))
 406                        add_pending_object(revs, object, tag->tag);
 407                if (!tag->tagged)
 408                        die("bad tag");
 409                object = parse_object(revs->repo, &tag->tagged->oid);
 410                if (!object) {
 411                        if (revs->ignore_missing_links || (flags & UNINTERESTING))
 412                                return NULL;
 413                        if (revs->exclude_promisor_objects &&
 414                            is_promisor_object(&tag->tagged->oid))
 415                                return NULL;
 416                        die("bad object %s", oid_to_hex(&tag->tagged->oid));
 417                }
 418                object->flags |= flags;
 419                /*
 420                 * We'll handle the tagged object by looping or dropping
 421                 * through to the non-tag handlers below. Do not
 422                 * propagate path data from the tag's pending entry.
 423                 */
 424                path = NULL;
 425                mode = 0;
 426        }
 427
 428        /*
 429         * Commit object? Just return it, we'll do all the complex
 430         * reachability crud.
 431         */
 432        if (object->type == OBJ_COMMIT) {
 433                struct commit *commit = (struct commit *)object;
 434
 435                if (parse_commit(commit) < 0)
 436                        die("unable to parse commit %s", name);
 437                if (flags & UNINTERESTING) {
 438                        mark_parents_uninteresting(commit);
 439
 440                        if (!revs->topo_order || !generation_numbers_enabled(the_repository))
 441                                revs->limited = 1;
 442                }
 443                if (revs->sources) {
 444                        char **slot = revision_sources_at(revs->sources, commit);
 445
 446                        if (!*slot)
 447                                *slot = xstrdup(name);
 448                }
 449                return commit;
 450        }
 451
 452        /*
 453         * Tree object? Either mark it uninteresting, or add it
 454         * to the list of objects to look at later..
 455         */
 456        if (object->type == OBJ_TREE) {
 457                struct tree *tree = (struct tree *)object;
 458                if (!revs->tree_objects)
 459                        return NULL;
 460                if (flags & UNINTERESTING) {
 461                        mark_tree_contents_uninteresting(revs->repo, tree);
 462                        return NULL;
 463                }
 464                add_pending_object_with_path(revs, object, name, mode, path);
 465                return NULL;
 466        }
 467
 468        /*
 469         * Blob object? You know the drill by now..
 470         */
 471        if (object->type == OBJ_BLOB) {
 472                if (!revs->blob_objects)
 473                        return NULL;
 474                if (flags & UNINTERESTING)
 475                        return NULL;
 476                add_pending_object_with_path(revs, object, name, mode, path);
 477                return NULL;
 478        }
 479        die("%s is unknown object", name);
 480}
 481
 482static int everybody_uninteresting(struct commit_list *orig,
 483                                   struct commit **interesting_cache)
 484{
 485        struct commit_list *list = orig;
 486
 487        if (*interesting_cache) {
 488                struct commit *commit = *interesting_cache;
 489                if (!(commit->object.flags & UNINTERESTING))
 490                        return 0;
 491        }
 492
 493        while (list) {
 494                struct commit *commit = list->item;
 495                list = list->next;
 496                if (commit->object.flags & UNINTERESTING)
 497                        continue;
 498
 499                *interesting_cache = commit;
 500                return 0;
 501        }
 502        return 1;
 503}
 504
 505/*
 506 * A definition of "relevant" commit that we can use to simplify limited graphs
 507 * by eliminating side branches.
 508 *
 509 * A "relevant" commit is one that is !UNINTERESTING (ie we are including it
 510 * in our list), or that is a specified BOTTOM commit. Then after computing
 511 * a limited list, during processing we can generally ignore boundary merges
 512 * coming from outside the graph, (ie from irrelevant parents), and treat
 513 * those merges as if they were single-parent. TREESAME is defined to consider
 514 * only relevant parents, if any. If we are TREESAME to our on-graph parents,
 515 * we don't care if we were !TREESAME to non-graph parents.
 516 *
 517 * Treating bottom commits as relevant ensures that a limited graph's
 518 * connection to the actual bottom commit is not viewed as a side branch, but
 519 * treated as part of the graph. For example:
 520 *
 521 *   ....Z...A---X---o---o---B
 522 *        .     /
 523 *         W---Y
 524 *
 525 * When computing "A..B", the A-X connection is at least as important as
 526 * Y-X, despite A being flagged UNINTERESTING.
 527 *
 528 * And when computing --ancestry-path "A..B", the A-X connection is more
 529 * important than Y-X, despite both A and Y being flagged UNINTERESTING.
 530 */
 531static inline int relevant_commit(struct commit *commit)
 532{
 533        return (commit->object.flags & (UNINTERESTING | BOTTOM)) != UNINTERESTING;
 534}
 535
 536/*
 537 * Return a single relevant commit from a parent list. If we are a TREESAME
 538 * commit, and this selects one of our parents, then we can safely simplify to
 539 * that parent.
 540 */
 541static struct commit *one_relevant_parent(const struct rev_info *revs,
 542                                          struct commit_list *orig)
 543{
 544        struct commit_list *list = orig;
 545        struct commit *relevant = NULL;
 546
 547        if (!orig)
 548                return NULL;
 549
 550        /*
 551         * For 1-parent commits, or if first-parent-only, then return that
 552         * first parent (even if not "relevant" by the above definition).
 553         * TREESAME will have been set purely on that parent.
 554         */
 555        if (revs->first_parent_only || !orig->next)
 556                return orig->item;
 557
 558        /*
 559         * For multi-parent commits, identify a sole relevant parent, if any.
 560         * If we have only one relevant parent, then TREESAME will be set purely
 561         * with regard to that parent, and we can simplify accordingly.
 562         *
 563         * If we have more than one relevant parent, or no relevant parents
 564         * (and multiple irrelevant ones), then we can't select a parent here
 565         * and return NULL.
 566         */
 567        while (list) {
 568                struct commit *commit = list->item;
 569                list = list->next;
 570                if (relevant_commit(commit)) {
 571                        if (relevant)
 572                                return NULL;
 573                        relevant = commit;
 574                }
 575        }
 576        return relevant;
 577}
 578
 579/*
 580 * The goal is to get REV_TREE_NEW as the result only if the
 581 * diff consists of all '+' (and no other changes), REV_TREE_OLD
 582 * if the whole diff is removal of old data, and otherwise
 583 * REV_TREE_DIFFERENT (of course if the trees are the same we
 584 * want REV_TREE_SAME).
 585 *
 586 * The only time we care about the distinction is when
 587 * remove_empty_trees is in effect, in which case we care only about
 588 * whether the whole change is REV_TREE_NEW, or if there's another type
 589 * of change. Which means we can stop the diff early in either of these
 590 * cases:
 591 *
 592 *   1. We're not using remove_empty_trees at all.
 593 *
 594 *   2. We saw anything except REV_TREE_NEW.
 595 */
 596static int tree_difference = REV_TREE_SAME;
 597
 598static void file_add_remove(struct diff_options *options,
 599                    int addremove, unsigned mode,
 600                    const struct object_id *oid,
 601                    int oid_valid,
 602                    const char *fullpath, unsigned dirty_submodule)
 603{
 604        int diff = addremove == '+' ? REV_TREE_NEW : REV_TREE_OLD;
 605        struct rev_info *revs = options->change_fn_data;
 606
 607        tree_difference |= diff;
 608        if (!revs->remove_empty_trees || tree_difference != REV_TREE_NEW)
 609                options->flags.has_changes = 1;
 610}
 611
 612static void file_change(struct diff_options *options,
 613                 unsigned old_mode, unsigned new_mode,
 614                 const struct object_id *old_oid,
 615                 const struct object_id *new_oid,
 616                 int old_oid_valid, int new_oid_valid,
 617                 const char *fullpath,
 618                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
 619{
 620        tree_difference = REV_TREE_DIFFERENT;
 621        options->flags.has_changes = 1;
 622}
 623
 624static int rev_compare_tree(struct rev_info *revs,
 625                            struct commit *parent, struct commit *commit)
 626{
 627        struct tree *t1 = get_commit_tree(parent);
 628        struct tree *t2 = get_commit_tree(commit);
 629
 630        if (!t1)
 631                return REV_TREE_NEW;
 632        if (!t2)
 633                return REV_TREE_OLD;
 634
 635        if (revs->simplify_by_decoration) {
 636                /*
 637                 * If we are simplifying by decoration, then the commit
 638                 * is worth showing if it has a tag pointing at it.
 639                 */
 640                if (get_name_decoration(&commit->object))
 641                        return REV_TREE_DIFFERENT;
 642                /*
 643                 * A commit that is not pointed by a tag is uninteresting
 644                 * if we are not limited by path.  This means that you will
 645                 * see the usual "commits that touch the paths" plus any
 646                 * tagged commit by specifying both --simplify-by-decoration
 647                 * and pathspec.
 648                 */
 649                if (!revs->prune_data.nr)
 650                        return REV_TREE_SAME;
 651        }
 652
 653        tree_difference = REV_TREE_SAME;
 654        revs->pruning.flags.has_changes = 0;
 655        if (diff_tree_oid(&t1->object.oid, &t2->object.oid, "",
 656                           &revs->pruning) < 0)
 657                return REV_TREE_DIFFERENT;
 658        return tree_difference;
 659}
 660
 661static int rev_same_tree_as_empty(struct rev_info *revs, struct commit *commit)
 662{
 663        int retval;
 664        struct tree *t1 = get_commit_tree(commit);
 665
 666        if (!t1)
 667                return 0;
 668
 669        tree_difference = REV_TREE_SAME;
 670        revs->pruning.flags.has_changes = 0;
 671        retval = diff_tree_oid(NULL, &t1->object.oid, "", &revs->pruning);
 672
 673        return retval >= 0 && (tree_difference == REV_TREE_SAME);
 674}
 675
 676struct treesame_state {
 677        unsigned int nparents;
 678        unsigned char treesame[FLEX_ARRAY];
 679};
 680
 681static struct treesame_state *initialise_treesame(struct rev_info *revs, struct commit *commit)
 682{
 683        unsigned n = commit_list_count(commit->parents);
 684        struct treesame_state *st = xcalloc(1, st_add(sizeof(*st), n));
 685        st->nparents = n;
 686        add_decoration(&revs->treesame, &commit->object, st);
 687        return st;
 688}
 689
 690/*
 691 * Must be called immediately after removing the nth_parent from a commit's
 692 * parent list, if we are maintaining the per-parent treesame[] decoration.
 693 * This does not recalculate the master TREESAME flag - update_treesame()
 694 * should be called to update it after a sequence of treesame[] modifications
 695 * that may have affected it.
 696 */
 697static int compact_treesame(struct rev_info *revs, struct commit *commit, unsigned nth_parent)
 698{
 699        struct treesame_state *st;
 700        int old_same;
 701
 702        if (!commit->parents) {
 703                /*
 704                 * Have just removed the only parent from a non-merge.
 705                 * Different handling, as we lack decoration.
 706                 */
 707                if (nth_parent != 0)
 708                        die("compact_treesame %u", nth_parent);
 709                old_same = !!(commit->object.flags & TREESAME);
 710                if (rev_same_tree_as_empty(revs, commit))
 711                        commit->object.flags |= TREESAME;
 712                else
 713                        commit->object.flags &= ~TREESAME;
 714                return old_same;
 715        }
 716
 717        st = lookup_decoration(&revs->treesame, &commit->object);
 718        if (!st || nth_parent >= st->nparents)
 719                die("compact_treesame %u", nth_parent);
 720
 721        old_same = st->treesame[nth_parent];
 722        memmove(st->treesame + nth_parent,
 723                st->treesame + nth_parent + 1,
 724                st->nparents - nth_parent - 1);
 725
 726        /*
 727         * If we've just become a non-merge commit, update TREESAME
 728         * immediately, and remove the no-longer-needed decoration.
 729         * If still a merge, defer update until update_treesame().
 730         */
 731        if (--st->nparents == 1) {
 732                if (commit->parents->next)
 733                        die("compact_treesame parents mismatch");
 734                if (st->treesame[0] && revs->dense)
 735                        commit->object.flags |= TREESAME;
 736                else
 737                        commit->object.flags &= ~TREESAME;
 738                free(add_decoration(&revs->treesame, &commit->object, NULL));
 739        }
 740
 741        return old_same;
 742}
 743
 744static unsigned update_treesame(struct rev_info *revs, struct commit *commit)
 745{
 746        if (commit->parents && commit->parents->next) {
 747                unsigned n;
 748                struct treesame_state *st;
 749                struct commit_list *p;
 750                unsigned relevant_parents;
 751                unsigned relevant_change, irrelevant_change;
 752
 753                st = lookup_decoration(&revs->treesame, &commit->object);
 754                if (!st)
 755                        die("update_treesame %s", oid_to_hex(&commit->object.oid));
 756                relevant_parents = 0;
 757                relevant_change = irrelevant_change = 0;
 758                for (p = commit->parents, n = 0; p; n++, p = p->next) {
 759                        if (relevant_commit(p->item)) {
 760                                relevant_change |= !st->treesame[n];
 761                                relevant_parents++;
 762                        } else
 763                                irrelevant_change |= !st->treesame[n];
 764                }
 765                if (relevant_parents ? relevant_change : irrelevant_change)
 766                        commit->object.flags &= ~TREESAME;
 767                else
 768                        commit->object.flags |= TREESAME;
 769        }
 770
 771        return commit->object.flags & TREESAME;
 772}
 773
 774static inline int limiting_can_increase_treesame(const struct rev_info *revs)
 775{
 776        /*
 777         * TREESAME is irrelevant unless prune && dense;
 778         * if simplify_history is set, we can't have a mixture of TREESAME and
 779         *    !TREESAME INTERESTING parents (and we don't have treesame[]
 780         *    decoration anyway);
 781         * if first_parent_only is set, then the TREESAME flag is locked
 782         *    against the first parent (and again we lack treesame[] decoration).
 783         */
 784        return revs->prune && revs->dense &&
 785               !revs->simplify_history &&
 786               !revs->first_parent_only;
 787}
 788
 789static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 790{
 791        struct commit_list **pp, *parent;
 792        struct treesame_state *ts = NULL;
 793        int relevant_change = 0, irrelevant_change = 0;
 794        int relevant_parents, nth_parent;
 795
 796        /*
 797         * If we don't do pruning, everything is interesting
 798         */
 799        if (!revs->prune)
 800                return;
 801
 802        if (!get_commit_tree(commit))
 803                return;
 804
 805        if (!commit->parents) {
 806                if (rev_same_tree_as_empty(revs, commit))
 807                        commit->object.flags |= TREESAME;
 808                return;
 809        }
 810
 811        /*
 812         * Normal non-merge commit? If we don't want to make the
 813         * history dense, we consider it always to be a change..
 814         */
 815        if (!revs->dense && !commit->parents->next)
 816                return;
 817
 818        for (pp = &commit->parents, nth_parent = 0, relevant_parents = 0;
 819             (parent = *pp) != NULL;
 820             pp = &parent->next, nth_parent++) {
 821                struct commit *p = parent->item;
 822                if (relevant_commit(p))
 823                        relevant_parents++;
 824
 825                if (nth_parent == 1) {
 826                        /*
 827                         * This our second loop iteration - so we now know
 828                         * we're dealing with a merge.
 829                         *
 830                         * Do not compare with later parents when we care only about
 831                         * the first parent chain, in order to avoid derailing the
 832                         * traversal to follow a side branch that brought everything
 833                         * in the path we are limited to by the pathspec.
 834                         */
 835                        if (revs->first_parent_only)
 836                                break;
 837                        /*
 838                         * If this will remain a potentially-simplifiable
 839                         * merge, remember per-parent treesame if needed.
 840                         * Initialise the array with the comparison from our
 841                         * first iteration.
 842                         */
 843                        if (revs->treesame.name &&
 844                            !revs->simplify_history &&
 845                            !(commit->object.flags & UNINTERESTING)) {
 846                                ts = initialise_treesame(revs, commit);
 847                                if (!(irrelevant_change || relevant_change))
 848                                        ts->treesame[0] = 1;
 849                        }
 850                }
 851                if (parse_commit(p) < 0)
 852                        die("cannot simplify commit %s (because of %s)",
 853                            oid_to_hex(&commit->object.oid),
 854                            oid_to_hex(&p->object.oid));
 855                switch (rev_compare_tree(revs, p, commit)) {
 856                case REV_TREE_SAME:
 857                        if (!revs->simplify_history || !relevant_commit(p)) {
 858                                /* Even if a merge with an uninteresting
 859                                 * side branch brought the entire change
 860                                 * we are interested in, we do not want
 861                                 * to lose the other branches of this
 862                                 * merge, so we just keep going.
 863                                 */
 864                                if (ts)
 865                                        ts->treesame[nth_parent] = 1;
 866                                continue;
 867                        }
 868                        parent->next = NULL;
 869                        commit->parents = parent;
 870                        commit->object.flags |= TREESAME;
 871                        return;
 872
 873                case REV_TREE_NEW:
 874                        if (revs->remove_empty_trees &&
 875                            rev_same_tree_as_empty(revs, p)) {
 876                                /* We are adding all the specified
 877                                 * paths from this parent, so the
 878                                 * history beyond this parent is not
 879                                 * interesting.  Remove its parents
 880                                 * (they are grandparents for us).
 881                                 * IOW, we pretend this parent is a
 882                                 * "root" commit.
 883                                 */
 884                                if (parse_commit(p) < 0)
 885                                        die("cannot simplify commit %s (invalid %s)",
 886                                            oid_to_hex(&commit->object.oid),
 887                                            oid_to_hex(&p->object.oid));
 888                                p->parents = NULL;
 889                        }
 890                /* fallthrough */
 891                case REV_TREE_OLD:
 892                case REV_TREE_DIFFERENT:
 893                        if (relevant_commit(p))
 894                                relevant_change = 1;
 895                        else
 896                                irrelevant_change = 1;
 897                        continue;
 898                }
 899                die("bad tree compare for commit %s", oid_to_hex(&commit->object.oid));
 900        }
 901
 902        /*
 903         * TREESAME is straightforward for single-parent commits. For merge
 904         * commits, it is most useful to define it so that "irrelevant"
 905         * parents cannot make us !TREESAME - if we have any relevant
 906         * parents, then we only consider TREESAMEness with respect to them,
 907         * allowing irrelevant merges from uninteresting branches to be
 908         * simplified away. Only if we have only irrelevant parents do we
 909         * base TREESAME on them. Note that this logic is replicated in
 910         * update_treesame, which should be kept in sync.
 911         */
 912        if (relevant_parents ? !relevant_change : !irrelevant_change)
 913                commit->object.flags |= TREESAME;
 914}
 915
 916static int process_parents(struct rev_info *revs, struct commit *commit,
 917                           struct commit_list **list, struct prio_queue *queue)
 918{
 919        struct commit_list *parent = commit->parents;
 920        unsigned left_flag;
 921
 922        if (commit->object.flags & ADDED)
 923                return 0;
 924        commit->object.flags |= ADDED;
 925
 926        if (revs->include_check &&
 927            !revs->include_check(commit, revs->include_check_data))
 928                return 0;
 929
 930        /*
 931         * If the commit is uninteresting, don't try to
 932         * prune parents - we want the maximal uninteresting
 933         * set.
 934         *
 935         * Normally we haven't parsed the parent
 936         * yet, so we won't have a parent of a parent
 937         * here. However, it may turn out that we've
 938         * reached this commit some other way (where it
 939         * wasn't uninteresting), in which case we need
 940         * to mark its parents recursively too..
 941         */
 942        if (commit->object.flags & UNINTERESTING) {
 943                while (parent) {
 944                        struct commit *p = parent->item;
 945                        parent = parent->next;
 946                        if (p)
 947                                p->object.flags |= UNINTERESTING;
 948                        if (parse_commit_gently(p, 1) < 0)
 949                                continue;
 950                        if (p->parents)
 951                                mark_parents_uninteresting(p);
 952                        if (p->object.flags & SEEN)
 953                                continue;
 954                        p->object.flags |= SEEN;
 955                        if (list)
 956                                commit_list_insert_by_date(p, list);
 957                        if (queue)
 958                                prio_queue_put(queue, p);
 959                }
 960                return 0;
 961        }
 962
 963        /*
 964         * Ok, the commit wasn't uninteresting. Try to
 965         * simplify the commit history and find the parent
 966         * that has no differences in the path set if one exists.
 967         */
 968        try_to_simplify_commit(revs, commit);
 969
 970        if (revs->no_walk)
 971                return 0;
 972
 973        left_flag = (commit->object.flags & SYMMETRIC_LEFT);
 974
 975        for (parent = commit->parents; parent; parent = parent->next) {
 976                struct commit *p = parent->item;
 977                int gently = revs->ignore_missing_links ||
 978                             revs->exclude_promisor_objects;
 979                if (parse_commit_gently(p, gently) < 0) {
 980                        if (revs->exclude_promisor_objects &&
 981                            is_promisor_object(&p->object.oid)) {
 982                                if (revs->first_parent_only)
 983                                        break;
 984                                continue;
 985                        }
 986                        return -1;
 987                }
 988                if (revs->sources) {
 989                        char **slot = revision_sources_at(revs->sources, p);
 990
 991                        if (!*slot)
 992                                *slot = *revision_sources_at(revs->sources, commit);
 993                }
 994                p->object.flags |= left_flag;
 995                if (!(p->object.flags & SEEN)) {
 996                        p->object.flags |= SEEN;
 997                        if (list)
 998                                commit_list_insert_by_date(p, list);
 999                        if (queue)
1000                                prio_queue_put(queue, p);
1001                }
1002                if (revs->first_parent_only)
1003                        break;
1004        }
1005        return 0;
1006}
1007
1008static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
1009{
1010        struct commit_list *p;
1011        int left_count = 0, right_count = 0;
1012        int left_first;
1013        struct patch_ids ids;
1014        unsigned cherry_flag;
1015
1016        /* First count the commits on the left and on the right */
1017        for (p = list; p; p = p->next) {
1018                struct commit *commit = p->item;
1019                unsigned flags = commit->object.flags;
1020                if (flags & BOUNDARY)
1021                        ;
1022                else if (flags & SYMMETRIC_LEFT)
1023                        left_count++;
1024                else
1025                        right_count++;
1026        }
1027
1028        if (!left_count || !right_count)
1029                return;
1030
1031        left_first = left_count < right_count;
1032        init_patch_ids(revs->repo, &ids);
1033        ids.diffopts.pathspec = revs->diffopt.pathspec;
1034
1035        /* Compute patch-ids for one side */
1036        for (p = list; p; p = p->next) {
1037                struct commit *commit = p->item;
1038                unsigned flags = commit->object.flags;
1039
1040                if (flags & BOUNDARY)
1041                        continue;
1042                /*
1043                 * If we have fewer left, left_first is set and we omit
1044                 * commits on the right branch in this loop.  If we have
1045                 * fewer right, we skip the left ones.
1046                 */
1047                if (left_first != !!(flags & SYMMETRIC_LEFT))
1048                        continue;
1049                add_commit_patch_id(commit, &ids);
1050        }
1051
1052        /* either cherry_mark or cherry_pick are true */
1053        cherry_flag = revs->cherry_mark ? PATCHSAME : SHOWN;
1054
1055        /* Check the other side */
1056        for (p = list; p; p = p->next) {
1057                struct commit *commit = p->item;
1058                struct patch_id *id;
1059                unsigned flags = commit->object.flags;
1060
1061                if (flags & BOUNDARY)
1062                        continue;
1063                /*
1064                 * If we have fewer left, left_first is set and we omit
1065                 * commits on the left branch in this loop.
1066                 */
1067                if (left_first == !!(flags & SYMMETRIC_LEFT))
1068                        continue;
1069
1070                /*
1071                 * Have we seen the same patch id?
1072                 */
1073                id = has_commit_patch_id(commit, &ids);
1074                if (!id)
1075                        continue;
1076
1077                commit->object.flags |= cherry_flag;
1078                id->commit->object.flags |= cherry_flag;
1079        }
1080
1081        free_patch_ids(&ids);
1082}
1083
1084/* How many extra uninteresting commits we want to see.. */
1085#define SLOP 5
1086
1087static int still_interesting(struct commit_list *src, timestamp_t date, int slop,
1088                             struct commit **interesting_cache)
1089{
1090        /*
1091         * No source list at all? We're definitely done..
1092         */
1093        if (!src)
1094                return 0;
1095
1096        /*
1097         * Does the destination list contain entries with a date
1098         * before the source list? Definitely _not_ done.
1099         */
1100        if (date <= src->item->date)
1101                return SLOP;
1102
1103        /*
1104         * Does the source list still have interesting commits in
1105         * it? Definitely not done..
1106         */
1107        if (!everybody_uninteresting(src, interesting_cache))
1108                return SLOP;
1109
1110        /* Ok, we're closing in.. */
1111        return slop-1;
1112}
1113
1114/*
1115 * "rev-list --ancestry-path A..B" computes commits that are ancestors
1116 * of B but not ancestors of A but further limits the result to those
1117 * that are descendants of A.  This takes the list of bottom commits and
1118 * the result of "A..B" without --ancestry-path, and limits the latter
1119 * further to the ones that can reach one of the commits in "bottom".
1120 */
1121static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *list)
1122{
1123        struct commit_list *p;
1124        struct commit_list *rlist = NULL;
1125        int made_progress;
1126
1127        /*
1128         * Reverse the list so that it will be likely that we would
1129         * process parents before children.
1130         */
1131        for (p = list; p; p = p->next)
1132                commit_list_insert(p->item, &rlist);
1133
1134        for (p = bottom; p; p = p->next)
1135                p->item->object.flags |= TMP_MARK;
1136
1137        /*
1138         * Mark the ones that can reach bottom commits in "list",
1139         * in a bottom-up fashion.
1140         */
1141        do {
1142                made_progress = 0;
1143                for (p = rlist; p; p = p->next) {
1144                        struct commit *c = p->item;
1145                        struct commit_list *parents;
1146                        if (c->object.flags & (TMP_MARK | UNINTERESTING))
1147                                continue;
1148                        for (parents = c->parents;
1149                             parents;
1150                             parents = parents->next) {
1151                                if (!(parents->item->object.flags & TMP_MARK))
1152                                        continue;
1153                                c->object.flags |= TMP_MARK;
1154                                made_progress = 1;
1155                                break;
1156                        }
1157                }
1158        } while (made_progress);
1159
1160        /*
1161         * NEEDSWORK: decide if we want to remove parents that are
1162         * not marked with TMP_MARK from commit->parents for commits
1163         * in the resulting list.  We may not want to do that, though.
1164         */
1165
1166        /*
1167         * The ones that are not marked with TMP_MARK are uninteresting
1168         */
1169        for (p = list; p; p = p->next) {
1170                struct commit *c = p->item;
1171                if (c->object.flags & TMP_MARK)
1172                        continue;
1173                c->object.flags |= UNINTERESTING;
1174        }
1175
1176        /* We are done with the TMP_MARK */
1177        for (p = list; p; p = p->next)
1178                p->item->object.flags &= ~TMP_MARK;
1179        for (p = bottom; p; p = p->next)
1180                p->item->object.flags &= ~TMP_MARK;
1181        free_commit_list(rlist);
1182}
1183
1184/*
1185 * Before walking the history, keep the set of "negative" refs the
1186 * caller has asked to exclude.
1187 *
1188 * This is used to compute "rev-list --ancestry-path A..B", as we need
1189 * to filter the result of "A..B" further to the ones that can actually
1190 * reach A.
1191 */
1192static struct commit_list *collect_bottom_commits(struct commit_list *list)
1193{
1194        struct commit_list *elem, *bottom = NULL;
1195        for (elem = list; elem; elem = elem->next)
1196                if (elem->item->object.flags & BOTTOM)
1197                        commit_list_insert(elem->item, &bottom);
1198        return bottom;
1199}
1200
1201/* Assumes either left_only or right_only is set */
1202static void limit_left_right(struct commit_list *list, struct rev_info *revs)
1203{
1204        struct commit_list *p;
1205
1206        for (p = list; p; p = p->next) {
1207                struct commit *commit = p->item;
1208
1209                if (revs->right_only) {
1210                        if (commit->object.flags & SYMMETRIC_LEFT)
1211                                commit->object.flags |= SHOWN;
1212                } else  /* revs->left_only is set */
1213                        if (!(commit->object.flags & SYMMETRIC_LEFT))
1214                                commit->object.flags |= SHOWN;
1215        }
1216}
1217
1218static int limit_list(struct rev_info *revs)
1219{
1220        int slop = SLOP;
1221        timestamp_t date = TIME_MAX;
1222        struct commit_list *list = revs->commits;
1223        struct commit_list *newlist = NULL;
1224        struct commit_list **p = &newlist;
1225        struct commit_list *bottom = NULL;
1226        struct commit *interesting_cache = NULL;
1227
1228        if (revs->ancestry_path) {
1229                bottom = collect_bottom_commits(list);
1230                if (!bottom)
1231                        die("--ancestry-path given but there are no bottom commits");
1232        }
1233
1234        while (list) {
1235                struct commit *commit = pop_commit(&list);
1236                struct object *obj = &commit->object;
1237                show_early_output_fn_t show;
1238
1239                if (commit == interesting_cache)
1240                        interesting_cache = NULL;
1241
1242                if (revs->max_age != -1 && (commit->date < revs->max_age))
1243                        obj->flags |= UNINTERESTING;
1244                if (process_parents(revs, commit, &list, NULL) < 0)
1245                        return -1;
1246                if (obj->flags & UNINTERESTING) {
1247                        mark_parents_uninteresting(commit);
1248                        slop = still_interesting(list, date, slop, &interesting_cache);
1249                        if (slop)
1250                                continue;
1251                        break;
1252                }
1253                if (revs->min_age != -1 && (commit->date > revs->min_age))
1254                        continue;
1255                date = commit->date;
1256                p = &commit_list_insert(commit, p)->next;
1257
1258                show = show_early_output;
1259                if (!show)
1260                        continue;
1261
1262                show(revs, newlist);
1263                show_early_output = NULL;
1264        }
1265        if (revs->cherry_pick || revs->cherry_mark)
1266                cherry_pick_list(newlist, revs);
1267
1268        if (revs->left_only || revs->right_only)
1269                limit_left_right(newlist, revs);
1270
1271        if (bottom) {
1272                limit_to_ancestry(bottom, newlist);
1273                free_commit_list(bottom);
1274        }
1275
1276        /*
1277         * Check if any commits have become TREESAME by some of their parents
1278         * becoming UNINTERESTING.
1279         */
1280        if (limiting_can_increase_treesame(revs))
1281                for (list = newlist; list; list = list->next) {
1282                        struct commit *c = list->item;
1283                        if (c->object.flags & (UNINTERESTING | TREESAME))
1284                                continue;
1285                        update_treesame(revs, c);
1286                }
1287
1288        revs->commits = newlist;
1289        return 0;
1290}
1291
1292/*
1293 * Add an entry to refs->cmdline with the specified information.
1294 * *name is copied.
1295 */
1296static void add_rev_cmdline(struct rev_info *revs,
1297                            struct object *item,
1298                            const char *name,
1299                            int whence,
1300                            unsigned flags)
1301{
1302        struct rev_cmdline_info *info = &revs->cmdline;
1303        unsigned int nr = info->nr;
1304
1305        ALLOC_GROW(info->rev, nr + 1, info->alloc);
1306        info->rev[nr].item = item;
1307        info->rev[nr].name = xstrdup(name);
1308        info->rev[nr].whence = whence;
1309        info->rev[nr].flags = flags;
1310        info->nr++;
1311}
1312
1313static void add_rev_cmdline_list(struct rev_info *revs,
1314                                 struct commit_list *commit_list,
1315                                 int whence,
1316                                 unsigned flags)
1317{
1318        while (commit_list) {
1319                struct object *object = &commit_list->item->object;
1320                add_rev_cmdline(revs, object, oid_to_hex(&object->oid),
1321                                whence, flags);
1322                commit_list = commit_list->next;
1323        }
1324}
1325
1326struct all_refs_cb {
1327        int all_flags;
1328        int warned_bad_reflog;
1329        struct rev_info *all_revs;
1330        const char *name_for_errormsg;
1331        struct worktree *wt;
1332};
1333
1334int ref_excluded(struct string_list *ref_excludes, const char *path)
1335{
1336        struct string_list_item *item;
1337
1338        if (!ref_excludes)
1339                return 0;
1340        for_each_string_list_item(item, ref_excludes) {
1341                if (!wildmatch(item->string, path, 0))
1342                        return 1;
1343        }
1344        return 0;
1345}
1346
1347static int handle_one_ref(const char *path, const struct object_id *oid,
1348                          int flag, void *cb_data)
1349{
1350        struct all_refs_cb *cb = cb_data;
1351        struct object *object;
1352
1353        if (ref_excluded(cb->all_revs->ref_excludes, path))
1354            return 0;
1355
1356        object = get_reference(cb->all_revs, path, oid, cb->all_flags);
1357        add_rev_cmdline(cb->all_revs, object, path, REV_CMD_REF, cb->all_flags);
1358        add_pending_oid(cb->all_revs, path, oid, cb->all_flags);
1359        return 0;
1360}
1361
1362static void init_all_refs_cb(struct all_refs_cb *cb, struct rev_info *revs,
1363        unsigned flags)
1364{
1365        cb->all_revs = revs;
1366        cb->all_flags = flags;
1367        revs->rev_input_given = 1;
1368        cb->wt = NULL;
1369}
1370
1371void clear_ref_exclusion(struct string_list **ref_excludes_p)
1372{
1373        if (*ref_excludes_p) {
1374                string_list_clear(*ref_excludes_p, 0);
1375                free(*ref_excludes_p);
1376        }
1377        *ref_excludes_p = NULL;
1378}
1379
1380void add_ref_exclusion(struct string_list **ref_excludes_p, const char *exclude)
1381{
1382        if (!*ref_excludes_p) {
1383                *ref_excludes_p = xcalloc(1, sizeof(**ref_excludes_p));
1384                (*ref_excludes_p)->strdup_strings = 1;
1385        }
1386        string_list_append(*ref_excludes_p, exclude);
1387}
1388
1389static void handle_refs(struct ref_store *refs,
1390                        struct rev_info *revs, unsigned flags,
1391                        int (*for_each)(struct ref_store *, each_ref_fn, void *))
1392{
1393        struct all_refs_cb cb;
1394
1395        if (!refs) {
1396                /* this could happen with uninitialized submodules */
1397                return;
1398        }
1399
1400        init_all_refs_cb(&cb, revs, flags);
1401        for_each(refs, handle_one_ref, &cb);
1402}
1403
1404static void handle_one_reflog_commit(struct object_id *oid, void *cb_data)
1405{
1406        struct all_refs_cb *cb = cb_data;
1407        if (!is_null_oid(oid)) {
1408                struct object *o = parse_object(cb->all_revs->repo, oid);
1409                if (o) {
1410                        o->flags |= cb->all_flags;
1411                        /* ??? CMDLINEFLAGS ??? */
1412                        add_pending_object(cb->all_revs, o, "");
1413                }
1414                else if (!cb->warned_bad_reflog) {
1415                        warning("reflog of '%s' references pruned commits",
1416                                cb->name_for_errormsg);
1417                        cb->warned_bad_reflog = 1;
1418                }
1419        }
1420}
1421
1422static int handle_one_reflog_ent(struct object_id *ooid, struct object_id *noid,
1423                const char *email, timestamp_t timestamp, int tz,
1424                const char *message, void *cb_data)
1425{
1426        handle_one_reflog_commit(ooid, cb_data);
1427        handle_one_reflog_commit(noid, cb_data);
1428        return 0;
1429}
1430
1431static int handle_one_reflog(const char *refname_in_wt,
1432                             const struct object_id *oid,
1433                             int flag, void *cb_data)
1434{
1435        struct all_refs_cb *cb = cb_data;
1436        struct strbuf refname = STRBUF_INIT;
1437
1438        cb->warned_bad_reflog = 0;
1439        strbuf_worktree_ref(cb->wt, &refname, refname_in_wt);
1440        cb->name_for_errormsg = refname.buf;
1441        refs_for_each_reflog_ent(get_main_ref_store(the_repository),
1442                                 refname.buf,
1443                                 handle_one_reflog_ent, cb_data);
1444        strbuf_release(&refname);
1445        return 0;
1446}
1447
1448static void add_other_reflogs_to_pending(struct all_refs_cb *cb)
1449{
1450        struct worktree **worktrees, **p;
1451
1452        worktrees = get_worktrees(0);
1453        for (p = worktrees; *p; p++) {
1454                struct worktree *wt = *p;
1455
1456                if (wt->is_current)
1457                        continue;
1458
1459                cb->wt = wt;
1460                refs_for_each_reflog(get_worktree_ref_store(wt),
1461                                     handle_one_reflog,
1462                                     cb);
1463        }
1464        free_worktrees(worktrees);
1465}
1466
1467void add_reflogs_to_pending(struct rev_info *revs, unsigned flags)
1468{
1469        struct all_refs_cb cb;
1470
1471        cb.all_revs = revs;
1472        cb.all_flags = flags;
1473        cb.wt = NULL;
1474        for_each_reflog(handle_one_reflog, &cb);
1475
1476        if (!revs->single_worktree)
1477                add_other_reflogs_to_pending(&cb);
1478}
1479
1480static void add_cache_tree(struct cache_tree *it, struct rev_info *revs,
1481                           struct strbuf *path, unsigned int flags)
1482{
1483        size_t baselen = path->len;
1484        int i;
1485
1486        if (it->entry_count >= 0) {
1487                struct tree *tree = lookup_tree(revs->repo, &it->oid);
1488                tree->object.flags |= flags;
1489                add_pending_object_with_path(revs, &tree->object, "",
1490                                             040000, path->buf);
1491        }
1492
1493        for (i = 0; i < it->subtree_nr; i++) {
1494                struct cache_tree_sub *sub = it->down[i];
1495                strbuf_addf(path, "%s%s", baselen ? "/" : "", sub->name);
1496                add_cache_tree(sub->cache_tree, revs, path, flags);
1497                strbuf_setlen(path, baselen);
1498        }
1499
1500}
1501
1502static void do_add_index_objects_to_pending(struct rev_info *revs,
1503                                            struct index_state *istate,
1504                                            unsigned int flags)
1505{
1506        int i;
1507
1508        for (i = 0; i < istate->cache_nr; i++) {
1509                struct cache_entry *ce = istate->cache[i];
1510                struct blob *blob;
1511
1512                if (S_ISGITLINK(ce->ce_mode))
1513                        continue;
1514
1515                blob = lookup_blob(revs->repo, &ce->oid);
1516                if (!blob)
1517                        die("unable to add index blob to traversal");
1518                blob->object.flags |= flags;
1519                add_pending_object_with_path(revs, &blob->object, "",
1520                                             ce->ce_mode, ce->name);
1521        }
1522
1523        if (istate->cache_tree) {
1524                struct strbuf path = STRBUF_INIT;
1525                add_cache_tree(istate->cache_tree, revs, &path, flags);
1526                strbuf_release(&path);
1527        }
1528}
1529
1530void add_index_objects_to_pending(struct rev_info *revs, unsigned int flags)
1531{
1532        struct worktree **worktrees, **p;
1533
1534        repo_read_index(revs->repo);
1535        do_add_index_objects_to_pending(revs, revs->repo->index, flags);
1536
1537        if (revs->single_worktree)
1538                return;
1539
1540        worktrees = get_worktrees(0);
1541        for (p = worktrees; *p; p++) {
1542                struct worktree *wt = *p;
1543                struct index_state istate = { NULL };
1544
1545                if (wt->is_current)
1546                        continue; /* current index already taken care of */
1547
1548                if (read_index_from(&istate,
1549                                    worktree_git_path(wt, "index"),
1550                                    get_worktree_git_dir(wt)) > 0)
1551                        do_add_index_objects_to_pending(revs, &istate, flags);
1552                discard_index(&istate);
1553        }
1554        free_worktrees(worktrees);
1555}
1556
1557struct add_alternate_refs_data {
1558        struct rev_info *revs;
1559        unsigned int flags;
1560};
1561
1562static void add_one_alternate_ref(const struct object_id *oid,
1563                                  void *vdata)
1564{
1565        const char *name = ".alternate";
1566        struct add_alternate_refs_data *data = vdata;
1567        struct object *obj;
1568
1569        obj = get_reference(data->revs, name, oid, data->flags);
1570        add_rev_cmdline(data->revs, obj, name, REV_CMD_REV, data->flags);
1571        add_pending_object(data->revs, obj, name);
1572}
1573
1574static void add_alternate_refs_to_pending(struct rev_info *revs,
1575                                          unsigned int flags)
1576{
1577        struct add_alternate_refs_data data;
1578        data.revs = revs;
1579        data.flags = flags;
1580        for_each_alternate_ref(add_one_alternate_ref, &data);
1581}
1582
1583static int add_parents_only(struct rev_info *revs, const char *arg_, int flags,
1584                            int exclude_parent)
1585{
1586        struct object_id oid;
1587        struct object *it;
1588        struct commit *commit;
1589        struct commit_list *parents;
1590        int parent_number;
1591        const char *arg = arg_;
1592
1593        if (*arg == '^') {
1594                flags ^= UNINTERESTING | BOTTOM;
1595                arg++;
1596        }
1597        if (get_oid_committish(arg, &oid))
1598                return 0;
1599        while (1) {
1600                it = get_reference(revs, arg, &oid, 0);
1601                if (!it && revs->ignore_missing)
1602                        return 0;
1603                if (it->type != OBJ_TAG)
1604                        break;
1605                if (!((struct tag*)it)->tagged)
1606                        return 0;
1607                oidcpy(&oid, &((struct tag*)it)->tagged->oid);
1608        }
1609        if (it->type != OBJ_COMMIT)
1610                return 0;
1611        commit = (struct commit *)it;
1612        if (exclude_parent &&
1613            exclude_parent > commit_list_count(commit->parents))
1614                return 0;
1615        for (parents = commit->parents, parent_number = 1;
1616             parents;
1617             parents = parents->next, parent_number++) {
1618                if (exclude_parent && parent_number != exclude_parent)
1619                        continue;
1620
1621                it = &parents->item->object;
1622                it->flags |= flags;
1623                add_rev_cmdline(revs, it, arg_, REV_CMD_PARENTS_ONLY, flags);
1624                add_pending_object(revs, it, arg);
1625        }
1626        return 1;
1627}
1628
1629void repo_init_revisions(struct repository *r,
1630                         struct rev_info *revs,
1631                         const char *prefix)
1632{
1633        memset(revs, 0, sizeof(*revs));
1634
1635        revs->repo = r;
1636        revs->abbrev = DEFAULT_ABBREV;
1637        revs->ignore_merges = 1;
1638        revs->simplify_history = 1;
1639        revs->pruning.repo = r;
1640        revs->pruning.flags.recursive = 1;
1641        revs->pruning.flags.quick = 1;
1642        revs->pruning.add_remove = file_add_remove;
1643        revs->pruning.change = file_change;
1644        revs->pruning.change_fn_data = revs;
1645        revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
1646        revs->dense = 1;
1647        revs->prefix = prefix;
1648        revs->max_age = -1;
1649        revs->min_age = -1;
1650        revs->skip_count = -1;
1651        revs->max_count = -1;
1652        revs->max_parents = -1;
1653        revs->expand_tabs_in_log = -1;
1654
1655        revs->commit_format = CMIT_FMT_DEFAULT;
1656        revs->expand_tabs_in_log_default = 8;
1657
1658        init_grep_defaults(revs->repo);
1659        grep_init(&revs->grep_filter, revs->repo, prefix);
1660        revs->grep_filter.status_only = 1;
1661
1662        repo_diff_setup(revs->repo, &revs->diffopt);
1663        if (prefix && !revs->diffopt.prefix) {
1664                revs->diffopt.prefix = prefix;
1665                revs->diffopt.prefix_length = strlen(prefix);
1666        }
1667
1668        revs->notes_opt.use_default_notes = -1;
1669}
1670
1671static void add_pending_commit_list(struct rev_info *revs,
1672                                    struct commit_list *commit_list,
1673                                    unsigned int flags)
1674{
1675        while (commit_list) {
1676                struct object *object = &commit_list->item->object;
1677                object->flags |= flags;
1678                add_pending_object(revs, object, oid_to_hex(&object->oid));
1679                commit_list = commit_list->next;
1680        }
1681}
1682
1683static void prepare_show_merge(struct rev_info *revs)
1684{
1685        struct commit_list *bases;
1686        struct commit *head, *other;
1687        struct object_id oid;
1688        const char **prune = NULL;
1689        int i, prune_num = 1; /* counting terminating NULL */
1690        struct index_state *istate = revs->repo->index;
1691
1692        if (get_oid("HEAD", &oid))
1693                die("--merge without HEAD?");
1694        head = lookup_commit_or_die(&oid, "HEAD");
1695        if (get_oid("MERGE_HEAD", &oid))
1696                die("--merge without MERGE_HEAD?");
1697        other = lookup_commit_or_die(&oid, "MERGE_HEAD");
1698        add_pending_object(revs, &head->object, "HEAD");
1699        add_pending_object(revs, &other->object, "MERGE_HEAD");
1700        bases = get_merge_bases(head, other);
1701        add_rev_cmdline_list(revs, bases, REV_CMD_MERGE_BASE, UNINTERESTING | BOTTOM);
1702        add_pending_commit_list(revs, bases, UNINTERESTING | BOTTOM);
1703        free_commit_list(bases);
1704        head->object.flags |= SYMMETRIC_LEFT;
1705
1706        if (!istate->cache_nr)
1707                repo_read_index(revs->repo);
1708        for (i = 0; i < istate->cache_nr; i++) {
1709                const struct cache_entry *ce = istate->cache[i];
1710                if (!ce_stage(ce))
1711                        continue;
1712                if (ce_path_match(istate, ce, &revs->prune_data, NULL)) {
1713                        prune_num++;
1714                        REALLOC_ARRAY(prune, prune_num);
1715                        prune[prune_num-2] = ce->name;
1716                        prune[prune_num-1] = NULL;
1717                }
1718                while ((i+1 < istate->cache_nr) &&
1719                       ce_same_name(ce, istate->cache[i+1]))
1720                        i++;
1721        }
1722        clear_pathspec(&revs->prune_data);
1723        parse_pathspec(&revs->prune_data, PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL,
1724                       PATHSPEC_PREFER_FULL | PATHSPEC_LITERAL_PATH, "", prune);
1725        revs->limited = 1;
1726}
1727
1728static int dotdot_missing(const char *arg, char *dotdot,
1729                          struct rev_info *revs, int symmetric)
1730{
1731        if (revs->ignore_missing)
1732                return 0;
1733        /* de-munge so we report the full argument */
1734        *dotdot = '.';
1735        die(symmetric
1736            ? "Invalid symmetric difference expression %s"
1737            : "Invalid revision range %s", arg);
1738}
1739
1740static int handle_dotdot_1(const char *arg, char *dotdot,
1741                           struct rev_info *revs, int flags,
1742                           int cant_be_filename,
1743                           struct object_context *a_oc,
1744                           struct object_context *b_oc)
1745{
1746        const char *a_name, *b_name;
1747        struct object_id a_oid, b_oid;
1748        struct object *a_obj, *b_obj;
1749        unsigned int a_flags, b_flags;
1750        int symmetric = 0;
1751        unsigned int flags_exclude = flags ^ (UNINTERESTING | BOTTOM);
1752        unsigned int oc_flags = GET_OID_COMMITTISH | GET_OID_RECORD_PATH;
1753
1754        a_name = arg;
1755        if (!*a_name)
1756                a_name = "HEAD";
1757
1758        b_name = dotdot + 2;
1759        if (*b_name == '.') {
1760                symmetric = 1;
1761                b_name++;
1762        }
1763        if (!*b_name)
1764                b_name = "HEAD";
1765
1766        if (get_oid_with_context(revs->repo, a_name, oc_flags, &a_oid, a_oc) ||
1767            get_oid_with_context(revs->repo, b_name, oc_flags, &b_oid, b_oc))
1768                return -1;
1769
1770        if (!cant_be_filename) {
1771                *dotdot = '.';
1772                verify_non_filename(revs->prefix, arg);
1773                *dotdot = '\0';
1774        }
1775
1776        a_obj = parse_object(revs->repo, &a_oid);
1777        b_obj = parse_object(revs->repo, &b_oid);
1778        if (!a_obj || !b_obj)
1779                return dotdot_missing(arg, dotdot, revs, symmetric);
1780
1781        if (!symmetric) {
1782                /* just A..B */
1783                b_flags = flags;
1784                a_flags = flags_exclude;
1785        } else {
1786                /* A...B -- find merge bases between the two */
1787                struct commit *a, *b;
1788                struct commit_list *exclude;
1789
1790                a = lookup_commit_reference(revs->repo, &a_obj->oid);
1791                b = lookup_commit_reference(revs->repo, &b_obj->oid);
1792                if (!a || !b)
1793                        return dotdot_missing(arg, dotdot, revs, symmetric);
1794
1795                exclude = get_merge_bases(a, b);
1796                add_rev_cmdline_list(revs, exclude, REV_CMD_MERGE_BASE,
1797                                     flags_exclude);
1798                add_pending_commit_list(revs, exclude, flags_exclude);
1799                free_commit_list(exclude);
1800
1801                b_flags = flags;
1802                a_flags = flags | SYMMETRIC_LEFT;
1803        }
1804
1805        a_obj->flags |= a_flags;
1806        b_obj->flags |= b_flags;
1807        add_rev_cmdline(revs, a_obj, a_name, REV_CMD_LEFT, a_flags);
1808        add_rev_cmdline(revs, b_obj, b_name, REV_CMD_RIGHT, b_flags);
1809        add_pending_object_with_path(revs, a_obj, a_name, a_oc->mode, a_oc->path);
1810        add_pending_object_with_path(revs, b_obj, b_name, b_oc->mode, b_oc->path);
1811        return 0;
1812}
1813
1814static int handle_dotdot(const char *arg,
1815                         struct rev_info *revs, int flags,
1816                         int cant_be_filename)
1817{
1818        struct object_context a_oc, b_oc;
1819        char *dotdot = strstr(arg, "..");
1820        int ret;
1821
1822        if (!dotdot)
1823                return -1;
1824
1825        memset(&a_oc, 0, sizeof(a_oc));
1826        memset(&b_oc, 0, sizeof(b_oc));
1827
1828        *dotdot = '\0';
1829        ret = handle_dotdot_1(arg, dotdot, revs, flags, cant_be_filename,
1830                              &a_oc, &b_oc);
1831        *dotdot = '.';
1832
1833        free(a_oc.path);
1834        free(b_oc.path);
1835
1836        return ret;
1837}
1838
1839int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsigned revarg_opt)
1840{
1841        struct object_context oc;
1842        char *mark;
1843        struct object *object;
1844        struct object_id oid;
1845        int local_flags;
1846        const char *arg = arg_;
1847        int cant_be_filename = revarg_opt & REVARG_CANNOT_BE_FILENAME;
1848        unsigned get_sha1_flags = GET_OID_RECORD_PATH;
1849
1850        flags = flags & UNINTERESTING ? flags | BOTTOM : flags & ~BOTTOM;
1851
1852        if (!cant_be_filename && !strcmp(arg, "..")) {
1853                /*
1854                 * Just ".."?  That is not a range but the
1855                 * pathspec for the parent directory.
1856                 */
1857                return -1;
1858        }
1859
1860        if (!handle_dotdot(arg, revs, flags, revarg_opt))
1861                return 0;
1862
1863        mark = strstr(arg, "^@");
1864        if (mark && !mark[2]) {
1865                *mark = 0;
1866                if (add_parents_only(revs, arg, flags, 0))
1867                        return 0;
1868                *mark = '^';
1869        }
1870        mark = strstr(arg, "^!");
1871        if (mark && !mark[2]) {
1872                *mark = 0;
1873                if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM), 0))
1874                        *mark = '^';
1875        }
1876        mark = strstr(arg, "^-");
1877        if (mark) {
1878                int exclude_parent = 1;
1879
1880                if (mark[2]) {
1881                        char *end;
1882                        exclude_parent = strtoul(mark + 2, &end, 10);
1883                        if (*end != '\0' || !exclude_parent)
1884                                return -1;
1885                }
1886
1887                *mark = 0;
1888                if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM), exclude_parent))
1889                        *mark = '^';
1890        }
1891
1892        local_flags = 0;
1893        if (*arg == '^') {
1894                local_flags = UNINTERESTING | BOTTOM;
1895                arg++;
1896        }
1897
1898        if (revarg_opt & REVARG_COMMITTISH)
1899                get_sha1_flags |= GET_OID_COMMITTISH;
1900
1901        if (get_oid_with_context(revs->repo, arg, get_sha1_flags, &oid, &oc))
1902                return revs->ignore_missing ? 0 : -1;
1903        if (!cant_be_filename)
1904                verify_non_filename(revs->prefix, arg);
1905        object = get_reference(revs, arg, &oid, flags ^ local_flags);
1906        if (!object)
1907                return revs->ignore_missing ? 0 : -1;
1908        add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
1909        add_pending_object_with_path(revs, object, arg, oc.mode, oc.path);
1910        free(oc.path);
1911        return 0;
1912}
1913
1914static void read_pathspec_from_stdin(struct strbuf *sb,
1915                                     struct argv_array *prune)
1916{
1917        while (strbuf_getline(sb, stdin) != EOF)
1918                argv_array_push(prune, sb->buf);
1919}
1920
1921static void read_revisions_from_stdin(struct rev_info *revs,
1922                                      struct argv_array *prune)
1923{
1924        struct strbuf sb;
1925        int seen_dashdash = 0;
1926        int save_warning;
1927
1928        save_warning = warn_on_object_refname_ambiguity;
1929        warn_on_object_refname_ambiguity = 0;
1930
1931        strbuf_init(&sb, 1000);
1932        while (strbuf_getline(&sb, stdin) != EOF) {
1933                int len = sb.len;
1934                if (!len)
1935                        break;
1936                if (sb.buf[0] == '-') {
1937                        if (len == 2 && sb.buf[1] == '-') {
1938                                seen_dashdash = 1;
1939                                break;
1940                        }
1941                        die("options not supported in --stdin mode");
1942                }
1943                if (handle_revision_arg(sb.buf, revs, 0,
1944                                        REVARG_CANNOT_BE_FILENAME))
1945                        die("bad revision '%s'", sb.buf);
1946        }
1947        if (seen_dashdash)
1948                read_pathspec_from_stdin(&sb, prune);
1949
1950        strbuf_release(&sb);
1951        warn_on_object_refname_ambiguity = save_warning;
1952}
1953
1954static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
1955{
1956        append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
1957}
1958
1959static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
1960{
1961        append_header_grep_pattern(&revs->grep_filter, field, pattern);
1962}
1963
1964static void add_message_grep(struct rev_info *revs, const char *pattern)
1965{
1966        add_grep(revs, pattern, GREP_PATTERN_BODY);
1967}
1968
1969static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
1970                               int *unkc, const char **unkv,
1971                               const struct setup_revision_opt* opt)
1972{
1973        const char *arg = argv[0];
1974        const char *optarg;
1975        int argcount;
1976        const unsigned hexsz = the_hash_algo->hexsz;
1977
1978        /* pseudo revision arguments */
1979        if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
1980            !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
1981            !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
1982            !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
1983            !strcmp(arg, "--bisect") || starts_with(arg, "--glob=") ||
1984            !strcmp(arg, "--indexed-objects") ||
1985            !strcmp(arg, "--alternate-refs") ||
1986            starts_with(arg, "--exclude=") ||
1987            starts_with(arg, "--branches=") || starts_with(arg, "--tags=") ||
1988            starts_with(arg, "--remotes=") || starts_with(arg, "--no-walk="))
1989        {
1990                unkv[(*unkc)++] = arg;
1991                return 1;
1992        }
1993
1994        if ((argcount = parse_long_opt("max-count", argv, &optarg))) {
1995                revs->max_count = atoi(optarg);
1996                revs->no_walk = 0;
1997                return argcount;
1998        } else if ((argcount = parse_long_opt("skip", argv, &optarg))) {
1999                revs->skip_count = atoi(optarg);
2000                return argcount;
2001        } else if ((*arg == '-') && isdigit(arg[1])) {
2002                /* accept -<digit>, like traditional "head" */
2003                if (strtol_i(arg + 1, 10, &revs->max_count) < 0 ||
2004                    revs->max_count < 0)
2005                        die("'%s': not a non-negative integer", arg + 1);
2006                revs->no_walk = 0;
2007        } else if (!strcmp(arg, "-n")) {
2008                if (argc <= 1)
2009                        return error("-n requires an argument");
2010                revs->max_count = atoi(argv[1]);
2011                revs->no_walk = 0;
2012                return 2;
2013        } else if (skip_prefix(arg, "-n", &optarg)) {
2014                revs->max_count = atoi(optarg);
2015                revs->no_walk = 0;
2016        } else if ((argcount = parse_long_opt("max-age", argv, &optarg))) {
2017                revs->max_age = atoi(optarg);
2018                return argcount;
2019        } else if ((argcount = parse_long_opt("since", argv, &optarg))) {
2020                revs->max_age = approxidate(optarg);
2021                return argcount;
2022        } else if ((argcount = parse_long_opt("after", argv, &optarg))) {
2023                revs->max_age = approxidate(optarg);
2024                return argcount;
2025        } else if ((argcount = parse_long_opt("min-age", argv, &optarg))) {
2026                revs->min_age = atoi(optarg);
2027                return argcount;
2028        } else if ((argcount = parse_long_opt("before", argv, &optarg))) {
2029                revs->min_age = approxidate(optarg);
2030                return argcount;
2031        } else if ((argcount = parse_long_opt("until", argv, &optarg))) {
2032                revs->min_age = approxidate(optarg);
2033                return argcount;
2034        } else if (!strcmp(arg, "--first-parent")) {
2035                revs->first_parent_only = 1;
2036        } else if (!strcmp(arg, "--ancestry-path")) {
2037                revs->ancestry_path = 1;
2038                revs->simplify_history = 0;
2039                revs->limited = 1;
2040        } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
2041                init_reflog_walk(&revs->reflog_info);
2042        } else if (!strcmp(arg, "--default")) {
2043                if (argc <= 1)
2044                        return error("bad --default argument");
2045                revs->def = argv[1];
2046                return 2;
2047        } else if (!strcmp(arg, "--merge")) {
2048                revs->show_merge = 1;
2049        } else if (!strcmp(arg, "--topo-order")) {
2050                revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
2051                revs->topo_order = 1;
2052        } else if (!strcmp(arg, "--simplify-merges")) {
2053                revs->simplify_merges = 1;
2054                revs->topo_order = 1;
2055                revs->rewrite_parents = 1;
2056                revs->simplify_history = 0;
2057                revs->limited = 1;
2058        } else if (!strcmp(arg, "--simplify-by-decoration")) {
2059                revs->simplify_merges = 1;
2060                revs->topo_order = 1;
2061                revs->rewrite_parents = 1;
2062                revs->simplify_history = 0;
2063                revs->simplify_by_decoration = 1;
2064                revs->limited = 1;
2065                revs->prune = 1;
2066                load_ref_decorations(NULL, DECORATE_SHORT_REFS);
2067        } else if (!strcmp(arg, "--date-order")) {
2068                revs->sort_order = REV_SORT_BY_COMMIT_DATE;
2069                revs->topo_order = 1;
2070        } else if (!strcmp(arg, "--author-date-order")) {
2071                revs->sort_order = REV_SORT_BY_AUTHOR_DATE;
2072                revs->topo_order = 1;
2073        } else if (!strcmp(arg, "--early-output")) {
2074                revs->early_output = 100;
2075                revs->topo_order = 1;
2076        } else if (skip_prefix(arg, "--early-output=", &optarg)) {
2077                if (strtoul_ui(optarg, 10, &revs->early_output) < 0)
2078                        die("'%s': not a non-negative integer", optarg);
2079                revs->topo_order = 1;
2080        } else if (!strcmp(arg, "--parents")) {
2081                revs->rewrite_parents = 1;
2082                revs->print_parents = 1;
2083        } else if (!strcmp(arg, "--dense")) {
2084                revs->dense = 1;
2085        } else if (!strcmp(arg, "--sparse")) {
2086                revs->dense = 0;
2087        } else if (!strcmp(arg, "--in-commit-order")) {
2088                revs->tree_blobs_in_commit_order = 1;
2089        } else if (!strcmp(arg, "--remove-empty")) {
2090                revs->remove_empty_trees = 1;
2091        } else if (!strcmp(arg, "--merges")) {
2092                revs->min_parents = 2;
2093        } else if (!strcmp(arg, "--no-merges")) {
2094                revs->max_parents = 1;
2095        } else if (skip_prefix(arg, "--min-parents=", &optarg)) {
2096                revs->min_parents = atoi(optarg);
2097        } else if (!strcmp(arg, "--no-min-parents")) {
2098                revs->min_parents = 0;
2099        } else if (skip_prefix(arg, "--max-parents=", &optarg)) {
2100                revs->max_parents = atoi(optarg);
2101        } else if (!strcmp(arg, "--no-max-parents")) {
2102                revs->max_parents = -1;
2103        } else if (!strcmp(arg, "--boundary")) {
2104                revs->boundary = 1;
2105        } else if (!strcmp(arg, "--left-right")) {
2106                revs->left_right = 1;
2107        } else if (!strcmp(arg, "--left-only")) {
2108                if (revs->right_only)
2109                        die("--left-only is incompatible with --right-only"
2110                            " or --cherry");
2111                revs->left_only = 1;
2112        } else if (!strcmp(arg, "--right-only")) {
2113                if (revs->left_only)
2114                        die("--right-only is incompatible with --left-only");
2115                revs->right_only = 1;
2116        } else if (!strcmp(arg, "--cherry")) {
2117                if (revs->left_only)
2118                        die("--cherry is incompatible with --left-only");
2119                revs->cherry_mark = 1;
2120                revs->right_only = 1;
2121                revs->max_parents = 1;
2122                revs->limited = 1;
2123        } else if (!strcmp(arg, "--count")) {
2124                revs->count = 1;
2125        } else if (!strcmp(arg, "--cherry-mark")) {
2126                if (revs->cherry_pick)
2127                        die("--cherry-mark is incompatible with --cherry-pick");
2128                revs->cherry_mark = 1;
2129                revs->limited = 1; /* needs limit_list() */
2130        } else if (!strcmp(arg, "--cherry-pick")) {
2131                if (revs->cherry_mark)
2132                        die("--cherry-pick is incompatible with --cherry-mark");
2133                revs->cherry_pick = 1;
2134                revs->limited = 1;
2135        } else if (!strcmp(arg, "--objects")) {
2136                revs->tag_objects = 1;
2137                revs->tree_objects = 1;
2138                revs->blob_objects = 1;
2139        } else if (!strcmp(arg, "--objects-edge")) {
2140                revs->tag_objects = 1;
2141                revs->tree_objects = 1;
2142                revs->blob_objects = 1;
2143                revs->edge_hint = 1;
2144        } else if (!strcmp(arg, "--objects-edge-aggressive")) {
2145                revs->tag_objects = 1;
2146                revs->tree_objects = 1;
2147                revs->blob_objects = 1;
2148                revs->edge_hint = 1;
2149                revs->edge_hint_aggressive = 1;
2150        } else if (!strcmp(arg, "--verify-objects")) {
2151                revs->tag_objects = 1;
2152                revs->tree_objects = 1;
2153                revs->blob_objects = 1;
2154                revs->verify_objects = 1;
2155        } else if (!strcmp(arg, "--unpacked")) {
2156                revs->unpacked = 1;
2157        } else if (starts_with(arg, "--unpacked=")) {
2158                die("--unpacked=<packfile> no longer supported.");
2159        } else if (!strcmp(arg, "-r")) {
2160                revs->diff = 1;
2161                revs->diffopt.flags.recursive = 1;
2162        } else if (!strcmp(arg, "-t")) {
2163                revs->diff = 1;
2164                revs->diffopt.flags.recursive = 1;
2165                revs->diffopt.flags.tree_in_recursive = 1;
2166        } else if (!strcmp(arg, "-m")) {
2167                revs->ignore_merges = 0;
2168        } else if (!strcmp(arg, "-c")) {
2169                revs->diff = 1;
2170                revs->dense_combined_merges = 0;
2171                revs->combine_merges = 1;
2172        } else if (!strcmp(arg, "--combined-all-paths")) {
2173                revs->diff = 1;
2174                revs->combined_all_paths = 1;
2175        } else if (!strcmp(arg, "--cc")) {
2176                revs->diff = 1;
2177                revs->dense_combined_merges = 1;
2178                revs->combine_merges = 1;
2179        } else if (!strcmp(arg, "-v")) {
2180                revs->verbose_header = 1;
2181        } else if (!strcmp(arg, "--pretty")) {
2182                revs->verbose_header = 1;
2183                revs->pretty_given = 1;
2184                get_commit_format(NULL, revs);
2185        } else if (skip_prefix(arg, "--pretty=", &optarg) ||
2186                   skip_prefix(arg, "--format=", &optarg)) {
2187                /*
2188                 * Detached form ("--pretty X" as opposed to "--pretty=X")
2189                 * not allowed, since the argument is optional.
2190                 */
2191                revs->verbose_header = 1;
2192                revs->pretty_given = 1;
2193                get_commit_format(optarg, revs);
2194        } else if (!strcmp(arg, "--expand-tabs")) {
2195                revs->expand_tabs_in_log = 8;
2196        } else if (!strcmp(arg, "--no-expand-tabs")) {
2197                revs->expand_tabs_in_log = 0;
2198        } else if (skip_prefix(arg, "--expand-tabs=", &arg)) {
2199                int val;
2200                if (strtol_i(arg, 10, &val) < 0 || val < 0)
2201                        die("'%s': not a non-negative integer", arg);
2202                revs->expand_tabs_in_log = val;
2203        } else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
2204                revs->show_notes = 1;
2205                revs->show_notes_given = 1;
2206                revs->notes_opt.use_default_notes = 1;
2207        } else if (!strcmp(arg, "--show-signature")) {
2208                revs->show_signature = 1;
2209        } else if (!strcmp(arg, "--no-show-signature")) {
2210                revs->show_signature = 0;
2211        } else if (!strcmp(arg, "--show-linear-break")) {
2212                revs->break_bar = "                    ..........";
2213                revs->track_linear = 1;
2214                revs->track_first_time = 1;
2215        } else if (skip_prefix(arg, "--show-linear-break=", &optarg)) {
2216                revs->break_bar = xstrdup(optarg);
2217                revs->track_linear = 1;
2218                revs->track_first_time = 1;
2219        } else if (skip_prefix(arg, "--show-notes=", &optarg) ||
2220                   skip_prefix(arg, "--notes=", &optarg)) {
2221                struct strbuf buf = STRBUF_INIT;
2222                revs->show_notes = 1;
2223                revs->show_notes_given = 1;
2224                if (starts_with(arg, "--show-notes=") &&
2225                    revs->notes_opt.use_default_notes < 0)
2226                        revs->notes_opt.use_default_notes = 1;
2227                strbuf_addstr(&buf, optarg);
2228                expand_notes_ref(&buf);
2229                string_list_append(&revs->notes_opt.extra_notes_refs,
2230                                   strbuf_detach(&buf, NULL));
2231        } else if (!strcmp(arg, "--no-notes")) {
2232                revs->show_notes = 0;
2233                revs->show_notes_given = 1;
2234                revs->notes_opt.use_default_notes = -1;
2235                /* we have been strdup'ing ourselves, so trick
2236                 * string_list into free()ing strings */
2237                revs->notes_opt.extra_notes_refs.strdup_strings = 1;
2238                string_list_clear(&revs->notes_opt.extra_notes_refs, 0);
2239                revs->notes_opt.extra_notes_refs.strdup_strings = 0;
2240        } else if (!strcmp(arg, "--standard-notes")) {
2241                revs->show_notes_given = 1;
2242                revs->notes_opt.use_default_notes = 1;
2243        } else if (!strcmp(arg, "--no-standard-notes")) {
2244                revs->notes_opt.use_default_notes = 0;
2245        } else if (!strcmp(arg, "--oneline")) {
2246                revs->verbose_header = 1;
2247                get_commit_format("oneline", revs);
2248                revs->pretty_given = 1;
2249                revs->abbrev_commit = 1;
2250        } else if (!strcmp(arg, "--graph")) {
2251                revs->topo_order = 1;
2252                revs->rewrite_parents = 1;
2253                revs->graph = graph_init(revs);
2254        } else if (!strcmp(arg, "--root")) {
2255                revs->show_root_diff = 1;
2256        } else if (!strcmp(arg, "--no-commit-id")) {
2257                revs->no_commit_id = 1;
2258        } else if (!strcmp(arg, "--always")) {
2259                revs->always_show_header = 1;
2260        } else if (!strcmp(arg, "--no-abbrev")) {
2261                revs->abbrev = 0;
2262        } else if (!strcmp(arg, "--abbrev")) {
2263                revs->abbrev = DEFAULT_ABBREV;
2264        } else if (skip_prefix(arg, "--abbrev=", &optarg)) {
2265                revs->abbrev = strtoul(optarg, NULL, 10);
2266                if (revs->abbrev < MINIMUM_ABBREV)
2267                        revs->abbrev = MINIMUM_ABBREV;
2268                else if (revs->abbrev > hexsz)
2269                        revs->abbrev = hexsz;
2270        } else if (!strcmp(arg, "--abbrev-commit")) {
2271                revs->abbrev_commit = 1;
2272                revs->abbrev_commit_given = 1;
2273        } else if (!strcmp(arg, "--no-abbrev-commit")) {
2274                revs->abbrev_commit = 0;
2275        } else if (!strcmp(arg, "--full-diff")) {
2276                revs->diff = 1;
2277                revs->full_diff = 1;
2278        } else if (!strcmp(arg, "--full-history")) {
2279                revs->simplify_history = 0;
2280        } else if (!strcmp(arg, "--relative-date")) {
2281                revs->date_mode.type = DATE_RELATIVE;
2282                revs->date_mode_explicit = 1;
2283        } else if ((argcount = parse_long_opt("date", argv, &optarg))) {
2284                parse_date_format(optarg, &revs->date_mode);
2285                revs->date_mode_explicit = 1;
2286                return argcount;
2287        } else if (!strcmp(arg, "--log-size")) {
2288                revs->show_log_size = 1;
2289        }
2290        /*
2291         * Grepping the commit log
2292         */
2293        else if ((argcount = parse_long_opt("author", argv, &optarg))) {
2294                add_header_grep(revs, GREP_HEADER_AUTHOR, optarg);
2295                return argcount;
2296        } else if ((argcount = parse_long_opt("committer", argv, &optarg))) {
2297                add_header_grep(revs, GREP_HEADER_COMMITTER, optarg);
2298                return argcount;
2299        } else if ((argcount = parse_long_opt("grep-reflog", argv, &optarg))) {
2300                add_header_grep(revs, GREP_HEADER_REFLOG, optarg);
2301                return argcount;
2302        } else if ((argcount = parse_long_opt("grep", argv, &optarg))) {
2303                add_message_grep(revs, optarg);
2304                return argcount;
2305        } else if (!strcmp(arg, "--grep-debug")) {
2306                revs->grep_filter.debug = 1;
2307        } else if (!strcmp(arg, "--basic-regexp")) {
2308                revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_BRE;
2309        } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
2310                revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_ERE;
2311        } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
2312                revs->grep_filter.ignore_case = 1;
2313                revs->diffopt.pickaxe_opts |= DIFF_PICKAXE_IGNORE_CASE;
2314        } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
2315                revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_FIXED;
2316        } else if (!strcmp(arg, "--perl-regexp") || !strcmp(arg, "-P")) {
2317                revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_PCRE;
2318        } else if (!strcmp(arg, "--all-match")) {
2319                revs->grep_filter.all_match = 1;
2320        } else if (!strcmp(arg, "--invert-grep")) {
2321                revs->invert_grep = 1;
2322        } else if ((argcount = parse_long_opt("encoding", argv, &optarg))) {
2323                if (strcmp(optarg, "none"))
2324                        git_log_output_encoding = xstrdup(optarg);
2325                else
2326                        git_log_output_encoding = "";
2327                return argcount;
2328        } else if (!strcmp(arg, "--reverse")) {
2329                revs->reverse ^= 1;
2330        } else if (!strcmp(arg, "--children")) {
2331                revs->children.name = "children";
2332                revs->limited = 1;
2333        } else if (!strcmp(arg, "--ignore-missing")) {
2334                revs->ignore_missing = 1;
2335        } else if (opt && opt->allow_exclude_promisor_objects &&
2336                   !strcmp(arg, "--exclude-promisor-objects")) {
2337                if (fetch_if_missing)
2338                        BUG("exclude_promisor_objects can only be used when fetch_if_missing is 0");
2339                revs->exclude_promisor_objects = 1;
2340        } else {
2341                int opts = diff_opt_parse(&revs->diffopt, argv, argc, revs->prefix);
2342                if (!opts)
2343                        unkv[(*unkc)++] = arg;
2344                return opts;
2345        }
2346        if (revs->graph && revs->track_linear)
2347                die("--show-linear-break and --graph are incompatible");
2348
2349        return 1;
2350}
2351
2352void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
2353                        const struct option *options,
2354                        const char * const usagestr[])
2355{
2356        int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
2357                                    &ctx->cpidx, ctx->out, NULL);
2358        if (n <= 0) {
2359                error("unknown option `%s'", ctx->argv[0]);
2360                usage_with_options(usagestr, options);
2361        }
2362        ctx->argv += n;
2363        ctx->argc -= n;
2364}
2365
2366static int for_each_bisect_ref(struct ref_store *refs, each_ref_fn fn,
2367                               void *cb_data, const char *term)
2368{
2369        struct strbuf bisect_refs = STRBUF_INIT;
2370        int status;
2371        strbuf_addf(&bisect_refs, "refs/bisect/%s", term);
2372        status = refs_for_each_fullref_in(refs, bisect_refs.buf, fn, cb_data, 0);
2373        strbuf_release(&bisect_refs);
2374        return status;
2375}
2376
2377static int for_each_bad_bisect_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
2378{
2379        return for_each_bisect_ref(refs, fn, cb_data, term_bad);
2380}
2381
2382static int for_each_good_bisect_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
2383{
2384        return for_each_bisect_ref(refs, fn, cb_data, term_good);
2385}
2386
2387static int handle_revision_pseudo_opt(const char *submodule,
2388                                struct rev_info *revs,
2389                                int argc, const char **argv, int *flags)
2390{
2391        const char *arg = argv[0];
2392        const char *optarg;
2393        struct ref_store *refs;
2394        int argcount;
2395
2396        if (submodule) {
2397                /*
2398                 * We need some something like get_submodule_worktrees()
2399                 * before we can go through all worktrees of a submodule,
2400                 * .e.g with adding all HEADs from --all, which is not
2401                 * supported right now, so stick to single worktree.
2402                 */
2403                if (!revs->single_worktree)
2404                        BUG("--single-worktree cannot be used together with submodule");
2405                refs = get_submodule_ref_store(submodule);
2406        } else
2407                refs = get_main_ref_store(revs->repo);
2408
2409        /*
2410         * NOTE!
2411         *
2412         * Commands like "git shortlog" will not accept the options below
2413         * unless parse_revision_opt queues them (as opposed to erroring
2414         * out).
2415         *
2416         * When implementing your new pseudo-option, remember to
2417         * register it in the list at the top of handle_revision_opt.
2418         */
2419        if (!strcmp(arg, "--all")) {
2420                handle_refs(refs, revs, *flags, refs_for_each_ref);
2421                handle_refs(refs, revs, *flags, refs_head_ref);
2422                if (!revs->single_worktree) {
2423                        struct all_refs_cb cb;
2424
2425                        init_all_refs_cb(&cb, revs, *flags);
2426                        other_head_refs(handle_one_ref, &cb);
2427                }
2428                clear_ref_exclusion(&revs->ref_excludes);
2429        } else if (!strcmp(arg, "--branches")) {
2430                handle_refs(refs, revs, *flags, refs_for_each_branch_ref);
2431                clear_ref_exclusion(&revs->ref_excludes);
2432        } else if (!strcmp(arg, "--bisect")) {
2433                read_bisect_terms(&term_bad, &term_good);
2434                handle_refs(refs, revs, *flags, for_each_bad_bisect_ref);
2435                handle_refs(refs, revs, *flags ^ (UNINTERESTING | BOTTOM),
2436                            for_each_good_bisect_ref);
2437                revs->bisect = 1;
2438        } else if (!strcmp(arg, "--tags")) {
2439                handle_refs(refs, revs, *flags, refs_for_each_tag_ref);
2440                clear_ref_exclusion(&revs->ref_excludes);
2441        } else if (!strcmp(arg, "--remotes")) {
2442                handle_refs(refs, revs, *flags, refs_for_each_remote_ref);
2443                clear_ref_exclusion(&revs->ref_excludes);
2444        } else if ((argcount = parse_long_opt("glob", argv, &optarg))) {
2445                struct all_refs_cb cb;
2446                init_all_refs_cb(&cb, revs, *flags);
2447                for_each_glob_ref(handle_one_ref, optarg, &cb);
2448                clear_ref_exclusion(&revs->ref_excludes);
2449                return argcount;
2450        } else if ((argcount = parse_long_opt("exclude", argv, &optarg))) {
2451                add_ref_exclusion(&revs->ref_excludes, optarg);
2452                return argcount;
2453        } else if (skip_prefix(arg, "--branches=", &optarg)) {
2454                struct all_refs_cb cb;
2455                init_all_refs_cb(&cb, revs, *flags);
2456                for_each_glob_ref_in(handle_one_ref, optarg, "refs/heads/", &cb);
2457                clear_ref_exclusion(&revs->ref_excludes);
2458        } else if (skip_prefix(arg, "--tags=", &optarg)) {
2459                struct all_refs_cb cb;
2460                init_all_refs_cb(&cb, revs, *flags);
2461                for_each_glob_ref_in(handle_one_ref, optarg, "refs/tags/", &cb);
2462                clear_ref_exclusion(&revs->ref_excludes);
2463        } else if (skip_prefix(arg, "--remotes=", &optarg)) {
2464                struct all_refs_cb cb;
2465                init_all_refs_cb(&cb, revs, *flags);
2466                for_each_glob_ref_in(handle_one_ref, optarg, "refs/remotes/", &cb);
2467                clear_ref_exclusion(&revs->ref_excludes);
2468        } else if (!strcmp(arg, "--reflog")) {
2469                add_reflogs_to_pending(revs, *flags);
2470        } else if (!strcmp(arg, "--indexed-objects")) {
2471                add_index_objects_to_pending(revs, *flags);
2472        } else if (!strcmp(arg, "--alternate-refs")) {
2473                add_alternate_refs_to_pending(revs, *flags);
2474        } else if (!strcmp(arg, "--not")) {
2475                *flags ^= UNINTERESTING | BOTTOM;
2476        } else if (!strcmp(arg, "--no-walk")) {
2477                revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
2478        } else if (skip_prefix(arg, "--no-walk=", &optarg)) {
2479                /*
2480                 * Detached form ("--no-walk X" as opposed to "--no-walk=X")
2481                 * not allowed, since the argument is optional.
2482                 */
2483                if (!strcmp(optarg, "sorted"))
2484                        revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
2485                else if (!strcmp(optarg, "unsorted"))
2486                        revs->no_walk = REVISION_WALK_NO_WALK_UNSORTED;
2487                else
2488                        return error("invalid argument to --no-walk");
2489        } else if (!strcmp(arg, "--do-walk")) {
2490                revs->no_walk = 0;
2491        } else if (!strcmp(arg, "--single-worktree")) {
2492                revs->single_worktree = 1;
2493        } else {
2494                return 0;
2495        }
2496
2497        return 1;
2498}
2499
2500static void NORETURN diagnose_missing_default(const char *def)
2501{
2502        int flags;
2503        const char *refname;
2504
2505        refname = resolve_ref_unsafe(def, 0, NULL, &flags);
2506        if (!refname || !(flags & REF_ISSYMREF) || (flags & REF_ISBROKEN))
2507                die(_("your current branch appears to be broken"));
2508
2509        skip_prefix(refname, "refs/heads/", &refname);
2510        die(_("your current branch '%s' does not have any commits yet"),
2511            refname);
2512}
2513
2514/*
2515 * Parse revision information, filling in the "rev_info" structure,
2516 * and removing the used arguments from the argument list.
2517 *
2518 * Returns the number of arguments left that weren't recognized
2519 * (which are also moved to the head of the argument list)
2520 */
2521int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
2522{
2523        int i, flags, left, seen_dashdash, got_rev_arg = 0, revarg_opt;
2524        struct argv_array prune_data = ARGV_ARRAY_INIT;
2525        const char *submodule = NULL;
2526
2527        if (opt)
2528                submodule = opt->submodule;
2529
2530        /* First, search for "--" */
2531        if (opt && opt->assume_dashdash) {
2532                seen_dashdash = 1;
2533        } else {
2534                seen_dashdash = 0;
2535                for (i = 1; i < argc; i++) {
2536                        const char *arg = argv[i];
2537                        if (strcmp(arg, "--"))
2538                                continue;
2539                        argv[i] = NULL;
2540                        argc = i;
2541                        if (argv[i + 1])
2542                                argv_array_pushv(&prune_data, argv + i + 1);
2543                        seen_dashdash = 1;
2544                        break;
2545                }
2546        }
2547
2548        /* Second, deal with arguments and options */
2549        flags = 0;
2550        revarg_opt = opt ? opt->revarg_opt : 0;
2551        if (seen_dashdash)
2552                revarg_opt |= REVARG_CANNOT_BE_FILENAME;
2553        for (left = i = 1; i < argc; i++) {
2554                const char *arg = argv[i];
2555                if (*arg == '-') {
2556                        int opts;
2557
2558                        opts = handle_revision_pseudo_opt(submodule,
2559                                                revs, argc - i, argv + i,
2560                                                &flags);
2561                        if (opts > 0) {
2562                                i += opts - 1;
2563                                continue;
2564                        }
2565
2566                        if (!strcmp(arg, "--stdin")) {
2567                                if (revs->disable_stdin) {
2568                                        argv[left++] = arg;
2569                                        continue;
2570                                }
2571                                if (revs->read_from_stdin++)
2572                                        die("--stdin given twice?");
2573                                read_revisions_from_stdin(revs, &prune_data);
2574                                continue;
2575                        }
2576
2577                        opts = handle_revision_opt(revs, argc - i, argv + i,
2578                                                   &left, argv, opt);
2579                        if (opts > 0) {
2580                                i += opts - 1;
2581                                continue;
2582                        }
2583                        if (opts < 0)
2584                                exit(128);
2585                        continue;
2586                }
2587
2588
2589                if (handle_revision_arg(arg, revs, flags, revarg_opt)) {
2590                        int j;
2591                        if (seen_dashdash || *arg == '^')
2592                                die("bad revision '%s'", arg);
2593
2594                        /* If we didn't have a "--":
2595                         * (1) all filenames must exist;
2596                         * (2) all rev-args must not be interpretable
2597                         *     as a valid filename.
2598                         * but the latter we have checked in the main loop.
2599                         */
2600                        for (j = i; j < argc; j++)
2601                                verify_filename(revs->prefix, argv[j], j == i);
2602
2603                        argv_array_pushv(&prune_data, argv + i);
2604                        break;
2605                }
2606                else
2607                        got_rev_arg = 1;
2608        }
2609
2610        if (prune_data.argc) {
2611                /*
2612                 * If we need to introduce the magic "a lone ':' means no
2613                 * pathspec whatsoever", here is the place to do so.
2614                 *
2615                 * if (prune_data.nr == 1 && !strcmp(prune_data[0], ":")) {
2616                 *      prune_data.nr = 0;
2617                 *      prune_data.alloc = 0;
2618                 *      free(prune_data.path);
2619                 *      prune_data.path = NULL;
2620                 * } else {
2621                 *      terminate prune_data.alloc with NULL and
2622                 *      call init_pathspec() to set revs->prune_data here.
2623                 * }
2624                 */
2625                parse_pathspec(&revs->prune_data, 0, 0,
2626                               revs->prefix, prune_data.argv);
2627        }
2628        argv_array_clear(&prune_data);
2629
2630        if (revs->def == NULL)
2631                revs->def = opt ? opt->def : NULL;
2632        if (opt && opt->tweak)
2633                opt->tweak(revs, opt);
2634        if (revs->show_merge)
2635                prepare_show_merge(revs);
2636        if (revs->def && !revs->pending.nr && !revs->rev_input_given && !got_rev_arg) {
2637                struct object_id oid;
2638                struct object *object;
2639                struct object_context oc;
2640                if (get_oid_with_context(revs->repo, revs->def, 0, &oid, &oc))
2641                        diagnose_missing_default(revs->def);
2642                object = get_reference(revs, revs->def, &oid, 0);
2643                add_pending_object_with_mode(revs, object, revs->def, oc.mode);
2644        }
2645
2646        /* Did the user ask for any diff output? Run the diff! */
2647        if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
2648                revs->diff = 1;
2649
2650        /* Pickaxe, diff-filter and rename following need diffs */
2651        if ((revs->diffopt.pickaxe_opts & DIFF_PICKAXE_KINDS_MASK) ||
2652            revs->diffopt.filter ||
2653            revs->diffopt.flags.follow_renames)
2654                revs->diff = 1;
2655
2656        if (revs->diffopt.objfind)
2657                revs->simplify_history = 0;
2658
2659        if (revs->topo_order && !generation_numbers_enabled(the_repository))
2660                revs->limited = 1;
2661
2662        if (revs->prune_data.nr) {
2663                copy_pathspec(&revs->pruning.pathspec, &revs->prune_data);
2664                /* Can't prune commits with rename following: the paths change.. */
2665                if (!revs->diffopt.flags.follow_renames)
2666                        revs->prune = 1;
2667                if (!revs->full_diff)
2668                        copy_pathspec(&revs->diffopt.pathspec,
2669                                      &revs->prune_data);
2670        }
2671        if (revs->combine_merges)
2672                revs->ignore_merges = 0;
2673        if (revs->combined_all_paths && !revs->combine_merges)
2674                die("--combined-all-paths makes no sense without -c or --cc");
2675
2676        revs->diffopt.abbrev = revs->abbrev;
2677
2678        if (revs->line_level_traverse) {
2679                revs->limited = 1;
2680                revs->topo_order = 1;
2681        }
2682
2683        diff_setup_done(&revs->diffopt);
2684
2685        grep_commit_pattern_type(GREP_PATTERN_TYPE_UNSPECIFIED,
2686                                 &revs->grep_filter);
2687        compile_grep_patterns(&revs->grep_filter);
2688
2689        if (revs->reverse && revs->reflog_info)
2690                die("cannot combine --reverse with --walk-reflogs");
2691        if (revs->reflog_info && revs->limited)
2692                die("cannot combine --walk-reflogs with history-limiting options");
2693        if (revs->rewrite_parents && revs->children.name)
2694                die("cannot combine --parents and --children");
2695
2696        /*
2697         * Limitations on the graph functionality
2698         */
2699        if (revs->reverse && revs->graph)
2700                die("cannot combine --reverse with --graph");
2701
2702        if (revs->reflog_info && revs->graph)
2703                die("cannot combine --walk-reflogs with --graph");
2704        if (revs->no_walk && revs->graph)
2705                die("cannot combine --no-walk with --graph");
2706        if (!revs->reflog_info && revs->grep_filter.use_reflog_filter)
2707                die("cannot use --grep-reflog without --walk-reflogs");
2708
2709        if (revs->first_parent_only && revs->bisect)
2710                die(_("--first-parent is incompatible with --bisect"));
2711
2712        if (revs->line_level_traverse &&
2713            (revs->diffopt.output_format & ~(DIFF_FORMAT_PATCH | DIFF_FORMAT_NO_OUTPUT)))
2714                die(_("-L does not yet support diff formats besides -p and -s"));
2715
2716        if (revs->expand_tabs_in_log < 0)
2717                revs->expand_tabs_in_log = revs->expand_tabs_in_log_default;
2718
2719        return left;
2720}
2721
2722static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
2723{
2724        struct commit_list *l = xcalloc(1, sizeof(*l));
2725
2726        l->item = child;
2727        l->next = add_decoration(&revs->children, &parent->object, l);
2728}
2729
2730static int remove_duplicate_parents(struct rev_info *revs, struct commit *commit)
2731{
2732        struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2733        struct commit_list **pp, *p;
2734        int surviving_parents;
2735
2736        /* Examine existing parents while marking ones we have seen... */
2737        pp = &commit->parents;
2738        surviving_parents = 0;
2739        while ((p = *pp) != NULL) {
2740                struct commit *parent = p->item;
2741                if (parent->object.flags & TMP_MARK) {
2742                        *pp = p->next;
2743                        if (ts)
2744                                compact_treesame(revs, commit, surviving_parents);
2745                        continue;
2746                }
2747                parent->object.flags |= TMP_MARK;
2748                surviving_parents++;
2749                pp = &p->next;
2750        }
2751        /* clear the temporary mark */
2752        for (p = commit->parents; p; p = p->next) {
2753                p->item->object.flags &= ~TMP_MARK;
2754        }
2755        /* no update_treesame() - removing duplicates can't affect TREESAME */
2756        return surviving_parents;
2757}
2758
2759struct merge_simplify_state {
2760        struct commit *simplified;
2761};
2762
2763static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
2764{
2765        struct merge_simplify_state *st;
2766
2767        st = lookup_decoration(&revs->merge_simplification, &commit->object);
2768        if (!st) {
2769                st = xcalloc(1, sizeof(*st));
2770                add_decoration(&revs->merge_simplification, &commit->object, st);
2771        }
2772        return st;
2773}
2774
2775static int mark_redundant_parents(struct commit *commit)
2776{
2777        struct commit_list *h = reduce_heads(commit->parents);
2778        int i = 0, marked = 0;
2779        struct commit_list *po, *pn;
2780
2781        /* Want these for sanity-checking only */
2782        int orig_cnt = commit_list_count(commit->parents);
2783        int cnt = commit_list_count(h);
2784
2785        /*
2786         * Not ready to remove items yet, just mark them for now, based
2787         * on the output of reduce_heads(). reduce_heads outputs the reduced
2788         * set in its original order, so this isn't too hard.
2789         */
2790        po = commit->parents;
2791        pn = h;
2792        while (po) {
2793                if (pn && po->item == pn->item) {
2794                        pn = pn->next;
2795                        i++;
2796                } else {
2797                        po->item->object.flags |= TMP_MARK;
2798                        marked++;
2799                }
2800                po=po->next;
2801        }
2802
2803        if (i != cnt || cnt+marked != orig_cnt)
2804                die("mark_redundant_parents %d %d %d %d", orig_cnt, cnt, i, marked);
2805
2806        free_commit_list(h);
2807
2808        return marked;
2809}
2810
2811static int mark_treesame_root_parents(struct commit *commit)
2812{
2813        struct commit_list *p;
2814        int marked = 0;
2815
2816        for (p = commit->parents; p; p = p->next) {
2817                struct commit *parent = p->item;
2818                if (!parent->parents && (parent->object.flags & TREESAME)) {
2819                        parent->object.flags |= TMP_MARK;
2820                        marked++;
2821                }
2822        }
2823
2824        return marked;
2825}
2826
2827/*
2828 * Awkward naming - this means one parent we are TREESAME to.
2829 * cf mark_treesame_root_parents: root parents that are TREESAME (to an
2830 * empty tree). Better name suggestions?
2831 */
2832static int leave_one_treesame_to_parent(struct rev_info *revs, struct commit *commit)
2833{
2834        struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2835        struct commit *unmarked = NULL, *marked = NULL;
2836        struct commit_list *p;
2837        unsigned n;
2838
2839        for (p = commit->parents, n = 0; p; p = p->next, n++) {
2840                if (ts->treesame[n]) {
2841                        if (p->item->object.flags & TMP_MARK) {
2842                                if (!marked)
2843                                        marked = p->item;
2844                        } else {
2845                                if (!unmarked) {
2846                                        unmarked = p->item;
2847                                        break;
2848                                }
2849                        }
2850                }
2851        }
2852
2853        /*
2854         * If we are TREESAME to a marked-for-deletion parent, but not to any
2855         * unmarked parents, unmark the first TREESAME parent. This is the
2856         * parent that the default simplify_history==1 scan would have followed,
2857         * and it doesn't make sense to omit that path when asking for a
2858         * simplified full history. Retaining it improves the chances of
2859         * understanding odd missed merges that took an old version of a file.
2860         *
2861         * Example:
2862         *
2863         *   I--------*X       A modified the file, but mainline merge X used
2864         *    \       /        "-s ours", so took the version from I. X is
2865         *     `-*A--'         TREESAME to I and !TREESAME to A.
2866         *
2867         * Default log from X would produce "I". Without this check,
2868         * --full-history --simplify-merges would produce "I-A-X", showing
2869         * the merge commit X and that it changed A, but not making clear that
2870         * it had just taken the I version. With this check, the topology above
2871         * is retained.
2872         *
2873         * Note that it is possible that the simplification chooses a different
2874         * TREESAME parent from the default, in which case this test doesn't
2875         * activate, and we _do_ drop the default parent. Example:
2876         *
2877         *   I------X         A modified the file, but it was reverted in B,
2878         *    \    /          meaning mainline merge X is TREESAME to both
2879         *    *A-*B           parents.
2880         *
2881         * Default log would produce "I" by following the first parent;
2882         * --full-history --simplify-merges will produce "I-A-B". But this is a
2883         * reasonable result - it presents a logical full history leading from
2884         * I to X, and X is not an important merge.
2885         */
2886        if (!unmarked && marked) {
2887                marked->object.flags &= ~TMP_MARK;
2888                return 1;
2889        }
2890
2891        return 0;
2892}
2893
2894static int remove_marked_parents(struct rev_info *revs, struct commit *commit)
2895{
2896        struct commit_list **pp, *p;
2897        int nth_parent, removed = 0;
2898
2899        pp = &commit->parents;
2900        nth_parent = 0;
2901        while ((p = *pp) != NULL) {
2902                struct commit *parent = p->item;
2903                if (parent->object.flags & TMP_MARK) {
2904                        parent->object.flags &= ~TMP_MARK;
2905                        *pp = p->next;
2906                        free(p);
2907                        removed++;
2908                        compact_treesame(revs, commit, nth_parent);
2909                        continue;
2910                }
2911                pp = &p->next;
2912                nth_parent++;
2913        }
2914
2915        /* Removing parents can only increase TREESAMEness */
2916        if (removed && !(commit->object.flags & TREESAME))
2917                update_treesame(revs, commit);
2918
2919        return nth_parent;
2920}
2921
2922static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
2923{
2924        struct commit_list *p;
2925        struct commit *parent;
2926        struct merge_simplify_state *st, *pst;
2927        int cnt;
2928
2929        st = locate_simplify_state(revs, commit);
2930
2931        /*
2932         * Have we handled this one?
2933         */
2934        if (st->simplified)
2935                return tail;
2936
2937        /*
2938         * An UNINTERESTING commit simplifies to itself, so does a
2939         * root commit.  We do not rewrite parents of such commit
2940         * anyway.
2941         */
2942        if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
2943                st->simplified = commit;
2944                return tail;
2945        }
2946
2947        /*
2948         * Do we know what commit all of our parents that matter
2949         * should be rewritten to?  Otherwise we are not ready to
2950         * rewrite this one yet.
2951         */
2952        for (cnt = 0, p = commit->parents; p; p = p->next) {
2953                pst = locate_simplify_state(revs, p->item);
2954                if (!pst->simplified) {
2955                        tail = &commit_list_insert(p->item, tail)->next;
2956                        cnt++;
2957                }
2958                if (revs->first_parent_only)
2959                        break;
2960        }
2961        if (cnt) {
2962                tail = &commit_list_insert(commit, tail)->next;
2963                return tail;
2964        }
2965
2966        /*
2967         * Rewrite our list of parents. Note that this cannot
2968         * affect our TREESAME flags in any way - a commit is
2969         * always TREESAME to its simplification.
2970         */
2971        for (p = commit->parents; p; p = p->next) {
2972                pst = locate_simplify_state(revs, p->item);
2973                p->item = pst->simplified;
2974                if (revs->first_parent_only)
2975                        break;
2976        }
2977
2978        if (revs->first_parent_only)
2979                cnt = 1;
2980        else
2981                cnt = remove_duplicate_parents(revs, commit);
2982
2983        /*
2984         * It is possible that we are a merge and one side branch
2985         * does not have any commit that touches the given paths;
2986         * in such a case, the immediate parent from that branch
2987         * will be rewritten to be the merge base.
2988         *
2989         *      o----X          X: the commit we are looking at;
2990         *     /    /           o: a commit that touches the paths;
2991         * ---o----'
2992         *
2993         * Further, a merge of an independent branch that doesn't
2994         * touch the path will reduce to a treesame root parent:
2995         *
2996         *  ----o----X          X: the commit we are looking at;
2997         *          /           o: a commit that touches the paths;
2998         *         r            r: a root commit not touching the paths
2999         *
3000         * Detect and simplify both cases.
3001         */
3002        if (1 < cnt) {
3003                int marked = mark_redundant_parents(commit);
3004                marked += mark_treesame_root_parents(commit);
3005                if (marked)
3006                        marked -= leave_one_treesame_to_parent(revs, commit);
3007                if (marked)
3008                        cnt = remove_marked_parents(revs, commit);
3009        }
3010
3011        /*
3012         * A commit simplifies to itself if it is a root, if it is
3013         * UNINTERESTING, if it touches the given paths, or if it is a
3014         * merge and its parents don't simplify to one relevant commit
3015         * (the first two cases are already handled at the beginning of
3016         * this function).
3017         *
3018         * Otherwise, it simplifies to what its sole relevant parent
3019         * simplifies to.
3020         */
3021        if (!cnt ||
3022            (commit->object.flags & UNINTERESTING) ||
3023            !(commit->object.flags & TREESAME) ||
3024            (parent = one_relevant_parent(revs, commit->parents)) == NULL)
3025                st->simplified = commit;
3026        else {
3027                pst = locate_simplify_state(revs, parent);
3028                st->simplified = pst->simplified;
3029        }
3030        return tail;
3031}
3032
3033static void simplify_merges(struct rev_info *revs)
3034{
3035        struct commit_list *list, *next;
3036        struct commit_list *yet_to_do, **tail;
3037        struct commit *commit;
3038
3039        if (!revs->prune)
3040                return;
3041
3042        /* feed the list reversed */
3043        yet_to_do = NULL;
3044        for (list = revs->commits; list; list = next) {
3045                commit = list->item;
3046                next = list->next;
3047                /*
3048                 * Do not free(list) here yet; the original list
3049                 * is used later in this function.
3050                 */
3051                commit_list_insert(commit, &yet_to_do);
3052        }
3053        while (yet_to_do) {
3054                list = yet_to_do;
3055                yet_to_do = NULL;
3056                tail = &yet_to_do;
3057                while (list) {
3058                        commit = pop_commit(&list);
3059                        tail = simplify_one(revs, commit, tail);
3060                }
3061        }
3062
3063        /* clean up the result, removing the simplified ones */
3064        list = revs->commits;
3065        revs->commits = NULL;
3066        tail = &revs->commits;
3067        while (list) {
3068                struct merge_simplify_state *st;
3069
3070                commit = pop_commit(&list);
3071                st = locate_simplify_state(revs, commit);
3072                if (st->simplified == commit)
3073                        tail = &commit_list_insert(commit, tail)->next;
3074        }
3075}
3076
3077static void set_children(struct rev_info *revs)
3078{
3079        struct commit_list *l;
3080        for (l = revs->commits; l; l = l->next) {
3081                struct commit *commit = l->item;
3082                struct commit_list *p;
3083
3084                for (p = commit->parents; p; p = p->next)
3085                        add_child(revs, p->item, commit);
3086        }
3087}
3088
3089void reset_revision_walk(void)
3090{
3091        clear_object_flags(SEEN | ADDED | SHOWN);
3092}
3093
3094static int mark_uninteresting(const struct object_id *oid,
3095                              struct packed_git *pack,
3096                              uint32_t pos,
3097                              void *cb)
3098{
3099        struct rev_info *revs = cb;
3100        struct object *o = parse_object(revs->repo, oid);
3101        o->flags |= UNINTERESTING | SEEN;
3102        return 0;
3103}
3104
3105define_commit_slab(indegree_slab, int);
3106define_commit_slab(author_date_slab, timestamp_t);
3107
3108struct topo_walk_info {
3109        uint32_t min_generation;
3110        struct prio_queue explore_queue;
3111        struct prio_queue indegree_queue;
3112        struct prio_queue topo_queue;
3113        struct indegree_slab indegree;
3114        struct author_date_slab author_date;
3115};
3116
3117static inline void test_flag_and_insert(struct prio_queue *q, struct commit *c, int flag)
3118{
3119        if (c->object.flags & flag)
3120                return;
3121
3122        c->object.flags |= flag;
3123        prio_queue_put(q, c);
3124}
3125
3126static void explore_walk_step(struct rev_info *revs)
3127{
3128        struct topo_walk_info *info = revs->topo_walk_info;
3129        struct commit_list *p;
3130        struct commit *c = prio_queue_get(&info->explore_queue);
3131
3132        if (!c)
3133                return;
3134
3135        if (parse_commit_gently(c, 1) < 0)
3136                return;
3137
3138        if (revs->sort_order == REV_SORT_BY_AUTHOR_DATE)
3139                record_author_date(&info->author_date, c);
3140
3141        if (revs->max_age != -1 && (c->date < revs->max_age))
3142                c->object.flags |= UNINTERESTING;
3143
3144        if (process_parents(revs, c, NULL, NULL) < 0)
3145                return;
3146
3147        if (c->object.flags & UNINTERESTING)
3148                mark_parents_uninteresting(c);
3149
3150        for (p = c->parents; p; p = p->next)
3151                test_flag_and_insert(&info->explore_queue, p->item, TOPO_WALK_EXPLORED);
3152}
3153
3154static void explore_to_depth(struct rev_info *revs,
3155                             uint32_t gen_cutoff)
3156{
3157        struct topo_walk_info *info = revs->topo_walk_info;
3158        struct commit *c;
3159        while ((c = prio_queue_peek(&info->explore_queue)) &&
3160               c->generation >= gen_cutoff)
3161                explore_walk_step(revs);
3162}
3163
3164static void indegree_walk_step(struct rev_info *revs)
3165{
3166        struct commit_list *p;
3167        struct topo_walk_info *info = revs->topo_walk_info;
3168        struct commit *c = prio_queue_get(&info->indegree_queue);
3169
3170        if (!c)
3171                return;
3172
3173        if (parse_commit_gently(c, 1) < 0)
3174                return;
3175
3176        explore_to_depth(revs, c->generation);
3177
3178        for (p = c->parents; p; p = p->next) {
3179                struct commit *parent = p->item;
3180                int *pi = indegree_slab_at(&info->indegree, parent);
3181
3182                if (*pi)
3183                        (*pi)++;
3184                else
3185                        *pi = 2;
3186
3187                test_flag_and_insert(&info->indegree_queue, parent, TOPO_WALK_INDEGREE);
3188
3189                if (revs->first_parent_only)
3190                        return;
3191        }
3192}
3193
3194static void compute_indegrees_to_depth(struct rev_info *revs,
3195                                       uint32_t gen_cutoff)
3196{
3197        struct topo_walk_info *info = revs->topo_walk_info;
3198        struct commit *c;
3199        while ((c = prio_queue_peek(&info->indegree_queue)) &&
3200               c->generation >= gen_cutoff)
3201                indegree_walk_step(revs);
3202}
3203
3204static void init_topo_walk(struct rev_info *revs)
3205{
3206        struct topo_walk_info *info;
3207        struct commit_list *list;
3208        revs->topo_walk_info = xmalloc(sizeof(struct topo_walk_info));
3209        info = revs->topo_walk_info;
3210        memset(info, 0, sizeof(struct topo_walk_info));
3211
3212        init_indegree_slab(&info->indegree);
3213        memset(&info->explore_queue, 0, sizeof(info->explore_queue));
3214        memset(&info->indegree_queue, 0, sizeof(info->indegree_queue));
3215        memset(&info->topo_queue, 0, sizeof(info->topo_queue));
3216
3217        switch (revs->sort_order) {
3218        default: /* REV_SORT_IN_GRAPH_ORDER */
3219                info->topo_queue.compare = NULL;
3220                break;
3221        case REV_SORT_BY_COMMIT_DATE:
3222                info->topo_queue.compare = compare_commits_by_commit_date;
3223                break;
3224        case REV_SORT_BY_AUTHOR_DATE:
3225                init_author_date_slab(&info->author_date);
3226                info->topo_queue.compare = compare_commits_by_author_date;
3227                info->topo_queue.cb_data = &info->author_date;
3228                break;
3229        }
3230
3231        info->explore_queue.compare = compare_commits_by_gen_then_commit_date;
3232        info->indegree_queue.compare = compare_commits_by_gen_then_commit_date;
3233
3234        info->min_generation = GENERATION_NUMBER_INFINITY;
3235        for (list = revs->commits; list; list = list->next) {
3236                struct commit *c = list->item;
3237
3238                if (parse_commit_gently(c, 1))
3239                        continue;
3240
3241                test_flag_and_insert(&info->explore_queue, c, TOPO_WALK_EXPLORED);
3242                test_flag_and_insert(&info->indegree_queue, c, TOPO_WALK_INDEGREE);
3243
3244                if (c->generation < info->min_generation)
3245                        info->min_generation = c->generation;
3246
3247                *(indegree_slab_at(&info->indegree, c)) = 1;
3248
3249                if (revs->sort_order == REV_SORT_BY_AUTHOR_DATE)
3250                        record_author_date(&info->author_date, c);
3251        }
3252        compute_indegrees_to_depth(revs, info->min_generation);
3253
3254        for (list = revs->commits; list; list = list->next) {
3255                struct commit *c = list->item;
3256
3257                if (*(indegree_slab_at(&info->indegree, c)) == 1)
3258                        prio_queue_put(&info->topo_queue, c);
3259        }
3260
3261        /*
3262         * This is unfortunate; the initial tips need to be shown
3263         * in the order given from the revision traversal machinery.
3264         */
3265        if (revs->sort_order == REV_SORT_IN_GRAPH_ORDER)
3266                prio_queue_reverse(&info->topo_queue);
3267}
3268
3269static struct commit *next_topo_commit(struct rev_info *revs)
3270{
3271        struct commit *c;
3272        struct topo_walk_info *info = revs->topo_walk_info;
3273
3274        /* pop next off of topo_queue */
3275        c = prio_queue_get(&info->topo_queue);
3276
3277        if (c)
3278                *(indegree_slab_at(&info->indegree, c)) = 0;
3279
3280        return c;
3281}
3282
3283static void expand_topo_walk(struct rev_info *revs, struct commit *commit)
3284{
3285        struct commit_list *p;
3286        struct topo_walk_info *info = revs->topo_walk_info;
3287        if (process_parents(revs, commit, NULL, NULL) < 0) {
3288                if (!revs->ignore_missing_links)
3289                        die("Failed to traverse parents of commit %s",
3290                            oid_to_hex(&commit->object.oid));
3291        }
3292
3293        for (p = commit->parents; p; p = p->next) {
3294                struct commit *parent = p->item;
3295                int *pi;
3296
3297                if (parent->object.flags & UNINTERESTING)
3298                        continue;
3299
3300                if (parse_commit_gently(parent, 1) < 0)
3301                        continue;
3302
3303                if (parent->generation < info->min_generation) {
3304                        info->min_generation = parent->generation;
3305                        compute_indegrees_to_depth(revs, info->min_generation);
3306                }
3307
3308                pi = indegree_slab_at(&info->indegree, parent);
3309
3310                (*pi)--;
3311                if (*pi == 1)
3312                        prio_queue_put(&info->topo_queue, parent);
3313
3314                if (revs->first_parent_only)
3315                        return;
3316        }
3317}
3318
3319int prepare_revision_walk(struct rev_info *revs)
3320{
3321        int i;
3322        struct object_array old_pending;
3323        struct commit_list **next = &revs->commits;
3324
3325        memcpy(&old_pending, &revs->pending, sizeof(old_pending));
3326        revs->pending.nr = 0;
3327        revs->pending.alloc = 0;
3328        revs->pending.objects = NULL;
3329        for (i = 0; i < old_pending.nr; i++) {
3330                struct object_array_entry *e = old_pending.objects + i;
3331                struct commit *commit = handle_commit(revs, e);
3332                if (commit) {
3333                        if (!(commit->object.flags & SEEN)) {
3334                                commit->object.flags |= SEEN;
3335                                next = commit_list_append(commit, next);
3336                        }
3337                }
3338        }
3339        object_array_clear(&old_pending);
3340
3341        /* Signal whether we need per-parent treesame decoration */
3342        if (revs->simplify_merges ||
3343            (revs->limited && limiting_can_increase_treesame(revs)))
3344                revs->treesame.name = "treesame";
3345
3346        if (revs->exclude_promisor_objects) {
3347                for_each_packed_object(mark_uninteresting, revs,
3348                                       FOR_EACH_OBJECT_PROMISOR_ONLY);
3349        }
3350
3351        if (revs->no_walk != REVISION_WALK_NO_WALK_UNSORTED)
3352                commit_list_sort_by_date(&revs->commits);
3353        if (revs->no_walk)
3354                return 0;
3355        if (revs->limited) {
3356                if (limit_list(revs) < 0)
3357                        return -1;
3358                if (revs->topo_order)
3359                        sort_in_topological_order(&revs->commits, revs->sort_order);
3360        } else if (revs->topo_order)
3361                init_topo_walk(revs);
3362        if (revs->line_level_traverse)
3363                line_log_filter(revs);
3364        if (revs->simplify_merges)
3365                simplify_merges(revs);
3366        if (revs->children.name)
3367                set_children(revs);
3368        return 0;
3369}
3370
3371static enum rewrite_result rewrite_one_1(struct rev_info *revs,
3372                                         struct commit **pp,
3373                                         struct prio_queue *queue)
3374{
3375        for (;;) {
3376                struct commit *p = *pp;
3377                if (!revs->limited)
3378                        if (process_parents(revs, p, NULL, queue) < 0)
3379                                return rewrite_one_error;
3380                if (p->object.flags & UNINTERESTING)
3381                        return rewrite_one_ok;
3382                if (!(p->object.flags & TREESAME))
3383                        return rewrite_one_ok;
3384                if (!p->parents)
3385                        return rewrite_one_noparents;
3386                if ((p = one_relevant_parent(revs, p->parents)) == NULL)
3387                        return rewrite_one_ok;
3388                *pp = p;
3389        }
3390}
3391
3392static void merge_queue_into_list(struct prio_queue *q, struct commit_list **list)
3393{
3394        while (q->nr) {
3395                struct commit *item = prio_queue_peek(q);
3396                struct commit_list *p = *list;
3397
3398                if (p && p->item->date >= item->date)
3399                        list = &p->next;
3400                else {
3401                        p = commit_list_insert(item, list);
3402                        list = &p->next; /* skip newly added item */
3403                        prio_queue_get(q); /* pop item */
3404                }
3405        }
3406}
3407
3408static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
3409{
3410        struct prio_queue queue = { compare_commits_by_commit_date };
3411        enum rewrite_result ret = rewrite_one_1(revs, pp, &queue);
3412        merge_queue_into_list(&queue, &revs->commits);
3413        clear_prio_queue(&queue);
3414        return ret;
3415}
3416
3417int rewrite_parents(struct rev_info *revs, struct commit *commit,
3418        rewrite_parent_fn_t rewrite_parent)
3419{
3420        struct commit_list **pp = &commit->parents;
3421        while (*pp) {
3422                struct commit_list *parent = *pp;
3423                switch (rewrite_parent(revs, &parent->item)) {
3424                case rewrite_one_ok:
3425                        break;
3426                case rewrite_one_noparents:
3427                        *pp = parent->next;
3428                        continue;
3429                case rewrite_one_error:
3430                        return -1;
3431                }
3432                pp = &parent->next;
3433        }
3434        remove_duplicate_parents(revs, commit);
3435        return 0;
3436}
3437
3438static int commit_rewrite_person(struct strbuf *buf, const char *what, struct string_list *mailmap)
3439{
3440        char *person, *endp;
3441        size_t len, namelen, maillen;
3442        const char *name;
3443        const char *mail;
3444        struct ident_split ident;
3445
3446        person = strstr(buf->buf, what);
3447        if (!person)
3448                return 0;
3449
3450        person += strlen(what);
3451        endp = strchr(person, '\n');
3452        if (!endp)
3453                return 0;
3454
3455        len = endp - person;
3456
3457        if (split_ident_line(&ident, person, len))
3458                return 0;
3459
3460        mail = ident.mail_begin;
3461        maillen = ident.mail_end - ident.mail_begin;
3462        name = ident.name_begin;
3463        namelen = ident.name_end - ident.name_begin;
3464
3465        if (map_user(mailmap, &mail, &maillen, &name, &namelen)) {
3466                struct strbuf namemail = STRBUF_INIT;
3467
3468                strbuf_addf(&namemail, "%.*s <%.*s>",
3469                            (int)namelen, name, (int)maillen, mail);
3470
3471                strbuf_splice(buf, ident.name_begin - buf->buf,
3472                              ident.mail_end - ident.name_begin + 1,
3473                              namemail.buf, namemail.len);
3474
3475                strbuf_release(&namemail);
3476
3477                return 1;
3478        }
3479
3480        return 0;
3481}
3482
3483static int commit_match(struct commit *commit, struct rev_info *opt)
3484{
3485        int retval;
3486        const char *encoding;
3487        const char *message;
3488        struct strbuf buf = STRBUF_INIT;
3489
3490        if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
3491                return 1;
3492
3493        /* Prepend "fake" headers as needed */
3494        if (opt->grep_filter.use_reflog_filter) {
3495                strbuf_addstr(&buf, "reflog ");
3496                get_reflog_message(&buf, opt->reflog_info);
3497                strbuf_addch(&buf, '\n');
3498        }
3499
3500        /*
3501         * We grep in the user's output encoding, under the assumption that it
3502         * is the encoding they are most likely to write their grep pattern
3503         * for. In addition, it means we will match the "notes" encoding below,
3504         * so we will not end up with a buffer that has two different encodings
3505         * in it.
3506         */
3507        encoding = get_log_output_encoding();
3508        message = logmsg_reencode(commit, NULL, encoding);
3509
3510        /* Copy the commit to temporary if we are using "fake" headers */
3511        if (buf.len)
3512                strbuf_addstr(&buf, message);
3513
3514        if (opt->grep_filter.header_list && opt->mailmap) {
3515                if (!buf.len)
3516                        strbuf_addstr(&buf, message);
3517
3518                commit_rewrite_person(&buf, "\nauthor ", opt->mailmap);
3519                commit_rewrite_person(&buf, "\ncommitter ", opt->mailmap);
3520        }
3521
3522        /* Append "fake" message parts as needed */
3523        if (opt->show_notes) {
3524                if (!buf.len)
3525                        strbuf_addstr(&buf, message);
3526                format_display_notes(&commit->object.oid, &buf, encoding, 1);
3527        }
3528
3529        /*
3530         * Find either in the original commit message, or in the temporary.
3531         * Note that we cast away the constness of "message" here. It is
3532         * const because it may come from the cached commit buffer. That's OK,
3533         * because we know that it is modifiable heap memory, and that while
3534         * grep_buffer may modify it for speed, it will restore any
3535         * changes before returning.
3536         */
3537        if (buf.len)
3538                retval = grep_buffer(&opt->grep_filter, buf.buf, buf.len);
3539        else
3540                retval = grep_buffer(&opt->grep_filter,
3541                                     (char *)message, strlen(message));
3542        strbuf_release(&buf);
3543        unuse_commit_buffer(commit, message);
3544        return opt->invert_grep ? !retval : retval;
3545}
3546
3547static inline int want_ancestry(const struct rev_info *revs)
3548{
3549        return (revs->rewrite_parents || revs->children.name);
3550}
3551
3552/*
3553 * Return a timestamp to be used for --since/--until comparisons for this
3554 * commit, based on the revision options.
3555 */
3556static timestamp_t comparison_date(const struct rev_info *revs,
3557                                   struct commit *commit)
3558{
3559        return revs->reflog_info ?
3560                get_reflog_timestamp(revs->reflog_info) :
3561                commit->date;
3562}
3563
3564enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
3565{
3566        if (commit->object.flags & SHOWN)
3567                return commit_ignore;
3568        if (revs->unpacked && has_object_pack(&commit->object.oid))
3569                return commit_ignore;
3570        if (commit->object.flags & UNINTERESTING)
3571                return commit_ignore;
3572        if (revs->min_age != -1 &&
3573            comparison_date(revs, commit) > revs->min_age)
3574                        return commit_ignore;
3575        if (revs->min_parents || (revs->max_parents >= 0)) {
3576                int n = commit_list_count(commit->parents);
3577                if ((n < revs->min_parents) ||
3578                    ((revs->max_parents >= 0) && (n > revs->max_parents)))
3579                        return commit_ignore;
3580        }
3581        if (!commit_match(commit, revs))
3582                return commit_ignore;
3583        if (revs->prune && revs->dense) {
3584                /* Commit without changes? */
3585                if (commit->object.flags & TREESAME) {
3586                        int n;
3587                        struct commit_list *p;
3588                        /* drop merges unless we want parenthood */
3589                        if (!want_ancestry(revs))
3590                                return commit_ignore;
3591                        /*
3592                         * If we want ancestry, then need to keep any merges
3593                         * between relevant commits to tie together topology.
3594                         * For consistency with TREESAME and simplification
3595                         * use "relevant" here rather than just INTERESTING,
3596                         * to treat bottom commit(s) as part of the topology.
3597                         */
3598                        for (n = 0, p = commit->parents; p; p = p->next)
3599                                if (relevant_commit(p->item))
3600                                        if (++n >= 2)
3601                                                return commit_show;
3602                        return commit_ignore;
3603                }
3604        }
3605        return commit_show;
3606}
3607
3608define_commit_slab(saved_parents, struct commit_list *);
3609
3610#define EMPTY_PARENT_LIST ((struct commit_list *)-1)
3611
3612/*
3613 * You may only call save_parents() once per commit (this is checked
3614 * for non-root commits).
3615 */
3616static void save_parents(struct rev_info *revs, struct commit *commit)
3617{
3618        struct commit_list **pp;
3619
3620        if (!revs->saved_parents_slab) {
3621                revs->saved_parents_slab = xmalloc(sizeof(struct saved_parents));
3622                init_saved_parents(revs->saved_parents_slab);
3623        }
3624
3625        pp = saved_parents_at(revs->saved_parents_slab, commit);
3626
3627        /*
3628         * When walking with reflogs, we may visit the same commit
3629         * several times: once for each appearance in the reflog.
3630         *
3631         * In this case, save_parents() will be called multiple times.
3632         * We want to keep only the first set of parents.  We need to
3633         * store a sentinel value for an empty (i.e., NULL) parent
3634         * list to distinguish it from a not-yet-saved list, however.
3635         */
3636        if (*pp)
3637                return;
3638        if (commit->parents)
3639                *pp = copy_commit_list(commit->parents);
3640        else
3641                *pp = EMPTY_PARENT_LIST;
3642}
3643
3644static void free_saved_parents(struct rev_info *revs)
3645{
3646        if (revs->saved_parents_slab)
3647                clear_saved_parents(revs->saved_parents_slab);
3648}
3649
3650struct commit_list *get_saved_parents(struct rev_info *revs, const struct commit *commit)
3651{
3652        struct commit_list *parents;
3653
3654        if (!revs->saved_parents_slab)
3655                return commit->parents;
3656
3657        parents = *saved_parents_at(revs->saved_parents_slab, commit);
3658        if (parents == EMPTY_PARENT_LIST)
3659                return NULL;
3660        return parents;
3661}
3662
3663enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
3664{
3665        enum commit_action action = get_commit_action(revs, commit);
3666
3667        if (action == commit_show &&
3668            revs->prune && revs->dense && want_ancestry(revs)) {
3669                /*
3670                 * --full-diff on simplified parents is no good: it
3671                 * will show spurious changes from the commits that
3672                 * were elided.  So we save the parents on the side
3673                 * when --full-diff is in effect.
3674                 */
3675                if (revs->full_diff)
3676                        save_parents(revs, commit);
3677                if (rewrite_parents(revs, commit, rewrite_one) < 0)
3678                        return commit_error;
3679        }
3680        return action;
3681}
3682
3683static void track_linear(struct rev_info *revs, struct commit *commit)
3684{
3685        if (revs->track_first_time) {
3686                revs->linear = 1;
3687                revs->track_first_time = 0;
3688        } else {
3689                struct commit_list *p;
3690                for (p = revs->previous_parents; p; p = p->next)
3691                        if (p->item == NULL || /* first commit */
3692                            oideq(&p->item->object.oid, &commit->object.oid))
3693                                break;
3694                revs->linear = p != NULL;
3695        }
3696        if (revs->reverse) {
3697                if (revs->linear)
3698                        commit->object.flags |= TRACK_LINEAR;
3699        }
3700        free_commit_list(revs->previous_parents);
3701        revs->previous_parents = copy_commit_list(commit->parents);
3702}
3703
3704static struct commit *get_revision_1(struct rev_info *revs)
3705{
3706        while (1) {
3707                struct commit *commit;
3708
3709                if (revs->reflog_info)
3710                        commit = next_reflog_entry(revs->reflog_info);
3711                else if (revs->topo_walk_info)
3712                        commit = next_topo_commit(revs);
3713                else
3714                        commit = pop_commit(&revs->commits);
3715
3716                if (!commit)
3717                        return NULL;
3718
3719                if (revs->reflog_info)
3720                        commit->object.flags &= ~(ADDED | SEEN | SHOWN);
3721
3722                /*
3723                 * If we haven't done the list limiting, we need to look at
3724                 * the parents here. We also need to do the date-based limiting
3725                 * that we'd otherwise have done in limit_list().
3726                 */
3727                if (!revs->limited) {
3728                        if (revs->max_age != -1 &&
3729                            comparison_date(revs, commit) < revs->max_age)
3730                                continue;
3731
3732                        if (revs->reflog_info)
3733                                try_to_simplify_commit(revs, commit);
3734                        else if (revs->topo_walk_info)
3735                                expand_topo_walk(revs, commit);
3736                        else if (process_parents(revs, commit, &revs->commits, NULL) < 0) {
3737                                if (!revs->ignore_missing_links)
3738                                        die("Failed to traverse parents of commit %s",
3739                                                oid_to_hex(&commit->object.oid));
3740                        }
3741                }
3742
3743                switch (simplify_commit(revs, commit)) {
3744                case commit_ignore:
3745                        continue;
3746                case commit_error:
3747                        die("Failed to simplify parents of commit %s",
3748                            oid_to_hex(&commit->object.oid));
3749                default:
3750                        if (revs->track_linear)
3751                                track_linear(revs, commit);
3752                        return commit;
3753                }
3754        }
3755}
3756
3757/*
3758 * Return true for entries that have not yet been shown.  (This is an
3759 * object_array_each_func_t.)
3760 */
3761static int entry_unshown(struct object_array_entry *entry, void *cb_data_unused)
3762{
3763        return !(entry->item->flags & SHOWN);
3764}
3765
3766/*
3767 * If array is on the verge of a realloc, garbage-collect any entries
3768 * that have already been shown to try to free up some space.
3769 */
3770static void gc_boundary(struct object_array *array)
3771{
3772        if (array->nr == array->alloc)
3773                object_array_filter(array, entry_unshown, NULL);
3774}
3775
3776static void create_boundary_commit_list(struct rev_info *revs)
3777{
3778        unsigned i;
3779        struct commit *c;
3780        struct object_array *array = &revs->boundary_commits;
3781        struct object_array_entry *objects = array->objects;
3782
3783        /*
3784         * If revs->commits is non-NULL at this point, an error occurred in
3785         * get_revision_1().  Ignore the error and continue printing the
3786         * boundary commits anyway.  (This is what the code has always
3787         * done.)
3788         */
3789        if (revs->commits) {
3790                free_commit_list(revs->commits);
3791                revs->commits = NULL;
3792        }
3793
3794        /*
3795         * Put all of the actual boundary commits from revs->boundary_commits
3796         * into revs->commits
3797         */
3798        for (i = 0; i < array->nr; i++) {
3799                c = (struct commit *)(objects[i].item);
3800                if (!c)
3801                        continue;
3802                if (!(c->object.flags & CHILD_SHOWN))
3803                        continue;
3804                if (c->object.flags & (SHOWN | BOUNDARY))
3805                        continue;
3806                c->object.flags |= BOUNDARY;
3807                commit_list_insert(c, &revs->commits);
3808        }
3809
3810        /*
3811         * If revs->topo_order is set, sort the boundary commits
3812         * in topological order
3813         */
3814        sort_in_topological_order(&revs->commits, revs->sort_order);
3815}
3816
3817static struct commit *get_revision_internal(struct rev_info *revs)
3818{
3819        struct commit *c = NULL;
3820        struct commit_list *l;
3821
3822        if (revs->boundary == 2) {
3823                /*
3824                 * All of the normal commits have already been returned,
3825                 * and we are now returning boundary commits.
3826                 * create_boundary_commit_list() has populated
3827                 * revs->commits with the remaining commits to return.
3828                 */
3829                c = pop_commit(&revs->commits);
3830                if (c)
3831                        c->object.flags |= SHOWN;
3832                return c;
3833        }
3834
3835        /*
3836         * If our max_count counter has reached zero, then we are done. We
3837         * don't simply return NULL because we still might need to show
3838         * boundary commits. But we want to avoid calling get_revision_1, which
3839         * might do a considerable amount of work finding the next commit only
3840         * for us to throw it away.
3841         *
3842         * If it is non-zero, then either we don't have a max_count at all
3843         * (-1), or it is still counting, in which case we decrement.
3844         */
3845        if (revs->max_count) {
3846                c = get_revision_1(revs);
3847                if (c) {
3848                        while (revs->skip_count > 0) {
3849                                revs->skip_count--;
3850                                c = get_revision_1(revs);
3851                                if (!c)
3852                                        break;
3853                        }
3854                }
3855
3856                if (revs->max_count > 0)
3857                        revs->max_count--;
3858        }
3859
3860        if (c)
3861                c->object.flags |= SHOWN;
3862
3863        if (!revs->boundary)
3864                return c;
3865
3866        if (!c) {
3867                /*
3868                 * get_revision_1() runs out the commits, and
3869                 * we are done computing the boundaries.
3870                 * switch to boundary commits output mode.
3871                 */
3872                revs->boundary = 2;
3873
3874                /*
3875                 * Update revs->commits to contain the list of
3876                 * boundary commits.
3877                 */
3878                create_boundary_commit_list(revs);
3879
3880                return get_revision_internal(revs);
3881        }
3882
3883        /*
3884         * boundary commits are the commits that are parents of the
3885         * ones we got from get_revision_1() but they themselves are
3886         * not returned from get_revision_1().  Before returning
3887         * 'c', we need to mark its parents that they could be boundaries.
3888         */
3889
3890        for (l = c->parents; l; l = l->next) {
3891                struct object *p;
3892                p = &(l->item->object);
3893                if (p->flags & (CHILD_SHOWN | SHOWN))
3894                        continue;
3895                p->flags |= CHILD_SHOWN;
3896                gc_boundary(&revs->boundary_commits);
3897                add_object_array(p, NULL, &revs->boundary_commits);
3898        }
3899
3900        return c;
3901}
3902
3903struct commit *get_revision(struct rev_info *revs)
3904{
3905        struct commit *c;
3906        struct commit_list *reversed;
3907
3908        if (revs->reverse) {
3909                reversed = NULL;
3910                while ((c = get_revision_internal(revs)))
3911                        commit_list_insert(c, &reversed);
3912                revs->commits = reversed;
3913                revs->reverse = 0;
3914                revs->reverse_output_stage = 1;
3915        }
3916
3917        if (revs->reverse_output_stage) {
3918                c = pop_commit(&revs->commits);
3919                if (revs->track_linear)
3920                        revs->linear = !!(c && c->object.flags & TRACK_LINEAR);
3921                return c;
3922        }
3923
3924        c = get_revision_internal(revs);
3925        if (c && revs->graph)
3926                graph_update(revs->graph, c);
3927        if (!c) {
3928                free_saved_parents(revs);
3929                if (revs->previous_parents) {
3930                        free_commit_list(revs->previous_parents);
3931                        revs->previous_parents = NULL;
3932                }
3933        }
3934        return c;
3935}
3936
3937char *get_revision_mark(const struct rev_info *revs, const struct commit *commit)
3938{
3939        if (commit->object.flags & BOUNDARY)
3940                return "-";
3941        else if (commit->object.flags & UNINTERESTING)
3942                return "^";
3943        else if (commit->object.flags & PATCHSAME)
3944                return "=";
3945        else if (!revs || revs->left_right) {
3946                if (commit->object.flags & SYMMETRIC_LEFT)
3947                        return "<";
3948                else
3949                        return ">";
3950        } else if (revs->graph)
3951                return "*";
3952        else if (revs->cherry_mark)
3953                return "+";
3954        return "";
3955}
3956
3957void put_revision_mark(const struct rev_info *revs, const struct commit *commit)
3958{
3959        char *mark = get_revision_mark(revs, commit);
3960        if (!strlen(mark))
3961                return;
3962        fputs(mark, stdout);
3963        putchar(' ');
3964}