6607dabcc1749a8562637d6ed992874a890c5d07
   1#include "cache.h"
   2#include "tag.h"
   3#include "blob.h"
   4#include "tree.h"
   5#include "commit.h"
   6#include "diff.h"
   7#include "refs.h"
   8#include "revision.h"
   9#include "graph.h"
  10#include "grep.h"
  11#include "reflog-walk.h"
  12#include "patch-ids.h"
  13#include "decorate.h"
  14#include "log-tree.h"
  15#include "string-list.h"
  16#include "mailmap.h"
  17
  18volatile show_early_output_fn_t show_early_output;
  19
  20char *path_name(const struct name_path *path, const char *name)
  21{
  22        const struct name_path *p;
  23        char *n, *m;
  24        int nlen = strlen(name);
  25        int len = nlen + 1;
  26
  27        for (p = path; p; p = p->up) {
  28                if (p->elem_len)
  29                        len += p->elem_len + 1;
  30        }
  31        n = xmalloc(len);
  32        m = n + len - (nlen + 1);
  33        strcpy(m, name);
  34        for (p = path; p; p = p->up) {
  35                if (p->elem_len) {
  36                        m -= p->elem_len + 1;
  37                        memcpy(m, p->elem, p->elem_len);
  38                        m[p->elem_len] = '/';
  39                }
  40        }
  41        return n;
  42}
  43
  44static int show_path_component_truncated(FILE *out, const char *name, int len)
  45{
  46        int cnt;
  47        for (cnt = 0; cnt < len; cnt++) {
  48                int ch = name[cnt];
  49                if (!ch || ch == '\n')
  50                        return -1;
  51                fputc(ch, out);
  52        }
  53        return len;
  54}
  55
  56static int show_path_truncated(FILE *out, const struct name_path *path)
  57{
  58        int emitted, ours;
  59
  60        if (!path)
  61                return 0;
  62        emitted = show_path_truncated(out, path->up);
  63        if (emitted < 0)
  64                return emitted;
  65        if (emitted)
  66                fputc('/', out);
  67        ours = show_path_component_truncated(out, path->elem, path->elem_len);
  68        if (ours < 0)
  69                return ours;
  70        return ours || emitted;
  71}
  72
  73void show_object_with_name(FILE *out, struct object *obj, const struct name_path *path, const char *component)
  74{
  75        struct name_path leaf;
  76        leaf.up = (struct name_path *)path;
  77        leaf.elem = component;
  78        leaf.elem_len = strlen(component);
  79
  80        fprintf(out, "%s ", sha1_to_hex(obj->sha1));
  81        show_path_truncated(out, &leaf);
  82        fputc('\n', out);
  83}
  84
  85void add_object(struct object *obj,
  86                struct object_array *p,
  87                struct name_path *path,
  88                const char *name)
  89{
  90        add_object_array(obj, path_name(path, name), p);
  91}
  92
  93static void mark_blob_uninteresting(struct blob *blob)
  94{
  95        if (!blob)
  96                return;
  97        if (blob->object.flags & UNINTERESTING)
  98                return;
  99        blob->object.flags |= UNINTERESTING;
 100}
 101
 102void mark_tree_uninteresting(struct tree *tree)
 103{
 104        struct tree_desc desc;
 105        struct name_entry entry;
 106        struct object *obj = &tree->object;
 107
 108        if (!tree)
 109                return;
 110        if (obj->flags & UNINTERESTING)
 111                return;
 112        obj->flags |= UNINTERESTING;
 113        if (!has_sha1_file(obj->sha1))
 114                return;
 115        if (parse_tree(tree) < 0)
 116                die("bad tree %s", sha1_to_hex(obj->sha1));
 117
 118        init_tree_desc(&desc, tree->buffer, tree->size);
 119        while (tree_entry(&desc, &entry)) {
 120                switch (object_type(entry.mode)) {
 121                case OBJ_TREE:
 122                        mark_tree_uninteresting(lookup_tree(entry.sha1));
 123                        break;
 124                case OBJ_BLOB:
 125                        mark_blob_uninteresting(lookup_blob(entry.sha1));
 126                        break;
 127                default:
 128                        /* Subproject commit - not in this repository */
 129                        break;
 130                }
 131        }
 132
 133        /*
 134         * We don't care about the tree any more
 135         * after it has been marked uninteresting.
 136         */
 137        free(tree->buffer);
 138        tree->buffer = NULL;
 139}
 140
 141void mark_parents_uninteresting(struct commit *commit)
 142{
 143        struct commit_list *parents = NULL, *l;
 144
 145        for (l = commit->parents; l; l = l->next)
 146                commit_list_insert(l->item, &parents);
 147
 148        while (parents) {
 149                struct commit *commit = parents->item;
 150                l = parents;
 151                parents = parents->next;
 152                free(l);
 153
 154                while (commit) {
 155                        /*
 156                         * A missing commit is ok iff its parent is marked
 157                         * uninteresting.
 158                         *
 159                         * We just mark such a thing parsed, so that when
 160                         * it is popped next time around, we won't be trying
 161                         * to parse it and get an error.
 162                         */
 163                        if (!has_sha1_file(commit->object.sha1))
 164                                commit->object.parsed = 1;
 165
 166                        if (commit->object.flags & UNINTERESTING)
 167                                break;
 168
 169                        commit->object.flags |= UNINTERESTING;
 170
 171                        /*
 172                         * Normally we haven't parsed the parent
 173                         * yet, so we won't have a parent of a parent
 174                         * here. However, it may turn out that we've
 175                         * reached this commit some other way (where it
 176                         * wasn't uninteresting), in which case we need
 177                         * to mark its parents recursively too..
 178                         */
 179                        if (!commit->parents)
 180                                break;
 181
 182                        for (l = commit->parents->next; l; l = l->next)
 183                                commit_list_insert(l->item, &parents);
 184                        commit = commit->parents->item;
 185                }
 186        }
 187}
 188
 189static void add_pending_object_with_mode(struct rev_info *revs, struct object *obj, const char *name, unsigned mode)
 190{
 191        if (!obj)
 192                return;
 193        if (revs->no_walk && (obj->flags & UNINTERESTING))
 194                revs->no_walk = 0;
 195        if (revs->reflog_info && obj->type == OBJ_COMMIT) {
 196                struct strbuf buf = STRBUF_INIT;
 197                int len = interpret_branch_name(name, &buf);
 198                int st;
 199
 200                if (0 < len && name[len] && buf.len)
 201                        strbuf_addstr(&buf, name + len);
 202                st = add_reflog_for_walk(revs->reflog_info,
 203                                         (struct commit *)obj,
 204                                         buf.buf[0] ? buf.buf: name);
 205                strbuf_release(&buf);
 206                if (st)
 207                        return;
 208        }
 209        add_object_array_with_mode(obj, name, &revs->pending, mode);
 210}
 211
 212void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
 213{
 214        add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
 215}
 216
 217void add_head_to_pending(struct rev_info *revs)
 218{
 219        unsigned char sha1[20];
 220        struct object *obj;
 221        if (get_sha1("HEAD", sha1))
 222                return;
 223        obj = parse_object(sha1);
 224        if (!obj)
 225                return;
 226        add_pending_object(revs, obj, "HEAD");
 227}
 228
 229static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
 230{
 231        struct object *object;
 232
 233        object = parse_object(sha1);
 234        if (!object) {
 235                if (revs->ignore_missing)
 236                        return object;
 237                die("bad object %s", name);
 238        }
 239        object->flags |= flags;
 240        return object;
 241}
 242
 243void add_pending_sha1(struct rev_info *revs, const char *name,
 244                      const unsigned char *sha1, unsigned int flags)
 245{
 246        struct object *object = get_reference(revs, name, sha1, flags);
 247        add_pending_object(revs, object, name);
 248}
 249
 250static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
 251{
 252        unsigned long flags = object->flags;
 253
 254        /*
 255         * Tag object? Look what it points to..
 256         */
 257        while (object->type == OBJ_TAG) {
 258                struct tag *tag = (struct tag *) object;
 259                if (revs->tag_objects && !(flags & UNINTERESTING))
 260                        add_pending_object(revs, object, tag->tag);
 261                if (!tag->tagged)
 262                        die("bad tag");
 263                object = parse_object(tag->tagged->sha1);
 264                if (!object) {
 265                        if (flags & UNINTERESTING)
 266                                return NULL;
 267                        die("bad object %s", sha1_to_hex(tag->tagged->sha1));
 268                }
 269        }
 270
 271        /*
 272         * Commit object? Just return it, we'll do all the complex
 273         * reachability crud.
 274         */
 275        if (object->type == OBJ_COMMIT) {
 276                struct commit *commit = (struct commit *)object;
 277                if (parse_commit(commit) < 0)
 278                        die("unable to parse commit %s", name);
 279                if (flags & UNINTERESTING) {
 280                        commit->object.flags |= UNINTERESTING;
 281                        mark_parents_uninteresting(commit);
 282                        revs->limited = 1;
 283                }
 284                if (revs->show_source && !commit->util)
 285                        commit->util = (void *) name;
 286                return commit;
 287        }
 288
 289        /*
 290         * Tree object? Either mark it uninteresting, or add it
 291         * to the list of objects to look at later..
 292         */
 293        if (object->type == OBJ_TREE) {
 294                struct tree *tree = (struct tree *)object;
 295                if (!revs->tree_objects)
 296                        return NULL;
 297                if (flags & UNINTERESTING) {
 298                        mark_tree_uninteresting(tree);
 299                        return NULL;
 300                }
 301                add_pending_object(revs, object, "");
 302                return NULL;
 303        }
 304
 305        /*
 306         * Blob object? You know the drill by now..
 307         */
 308        if (object->type == OBJ_BLOB) {
 309                struct blob *blob = (struct blob *)object;
 310                if (!revs->blob_objects)
 311                        return NULL;
 312                if (flags & UNINTERESTING) {
 313                        mark_blob_uninteresting(blob);
 314                        return NULL;
 315                }
 316                add_pending_object(revs, object, "");
 317                return NULL;
 318        }
 319        die("%s is unknown object", name);
 320}
 321
 322static int everybody_uninteresting(struct commit_list *orig)
 323{
 324        struct commit_list *list = orig;
 325        while (list) {
 326                struct commit *commit = list->item;
 327                list = list->next;
 328                if (commit->object.flags & UNINTERESTING)
 329                        continue;
 330                return 0;
 331        }
 332        return 1;
 333}
 334
 335/*
 336 * The goal is to get REV_TREE_NEW as the result only if the
 337 * diff consists of all '+' (and no other changes), REV_TREE_OLD
 338 * if the whole diff is removal of old data, and otherwise
 339 * REV_TREE_DIFFERENT (of course if the trees are the same we
 340 * want REV_TREE_SAME).
 341 * That means that once we get to REV_TREE_DIFFERENT, we do not
 342 * have to look any further.
 343 */
 344static int tree_difference = REV_TREE_SAME;
 345
 346static void file_add_remove(struct diff_options *options,
 347                    int addremove, unsigned mode,
 348                    const unsigned char *sha1,
 349                    int sha1_valid,
 350                    const char *fullpath, unsigned dirty_submodule)
 351{
 352        int diff = addremove == '+' ? REV_TREE_NEW : REV_TREE_OLD;
 353
 354        tree_difference |= diff;
 355        if (tree_difference == REV_TREE_DIFFERENT)
 356                DIFF_OPT_SET(options, HAS_CHANGES);
 357}
 358
 359static void file_change(struct diff_options *options,
 360                 unsigned old_mode, unsigned new_mode,
 361                 const unsigned char *old_sha1,
 362                 const unsigned char *new_sha1,
 363                 int old_sha1_valid, int new_sha1_valid,
 364                 const char *fullpath,
 365                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
 366{
 367        tree_difference = REV_TREE_DIFFERENT;
 368        DIFF_OPT_SET(options, HAS_CHANGES);
 369}
 370
 371static int rev_compare_tree(struct rev_info *revs, struct commit *parent, struct commit *commit)
 372{
 373        struct tree *t1 = parent->tree;
 374        struct tree *t2 = commit->tree;
 375
 376        if (!t1)
 377                return REV_TREE_NEW;
 378        if (!t2)
 379                return REV_TREE_OLD;
 380
 381        if (revs->simplify_by_decoration) {
 382                /*
 383                 * If we are simplifying by decoration, then the commit
 384                 * is worth showing if it has a tag pointing at it.
 385                 */
 386                if (lookup_decoration(&name_decoration, &commit->object))
 387                        return REV_TREE_DIFFERENT;
 388                /*
 389                 * A commit that is not pointed by a tag is uninteresting
 390                 * if we are not limited by path.  This means that you will
 391                 * see the usual "commits that touch the paths" plus any
 392                 * tagged commit by specifying both --simplify-by-decoration
 393                 * and pathspec.
 394                 */
 395                if (!revs->prune_data.nr)
 396                        return REV_TREE_SAME;
 397        }
 398
 399        tree_difference = REV_TREE_SAME;
 400        DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 401        if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
 402                           &revs->pruning) < 0)
 403                return REV_TREE_DIFFERENT;
 404        return tree_difference;
 405}
 406
 407static int rev_same_tree_as_empty(struct rev_info *revs, struct commit *commit)
 408{
 409        int retval;
 410        void *tree;
 411        unsigned long size;
 412        struct tree_desc empty, real;
 413        struct tree *t1 = commit->tree;
 414
 415        if (!t1)
 416                return 0;
 417
 418        tree = read_object_with_reference(t1->object.sha1, tree_type, &size, NULL);
 419        if (!tree)
 420                return 0;
 421        init_tree_desc(&real, tree, size);
 422        init_tree_desc(&empty, "", 0);
 423
 424        tree_difference = REV_TREE_SAME;
 425        DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 426        retval = diff_tree(&empty, &real, "", &revs->pruning);
 427        free(tree);
 428
 429        return retval >= 0 && (tree_difference == REV_TREE_SAME);
 430}
 431
 432struct treesame_state {
 433        unsigned int nparents;
 434        unsigned char treesame[FLEX_ARRAY];
 435};
 436
 437static struct treesame_state *initialise_treesame(struct rev_info *revs, struct commit *commit)
 438{
 439        unsigned n = commit_list_count(commit->parents);
 440        struct treesame_state *st = xcalloc(1, sizeof(*st) + n);
 441        st->nparents = n;
 442        add_decoration(&revs->treesame, &commit->object, st);
 443        return st;
 444}
 445
 446/*
 447 * Must be called immediately after removing the nth_parent from a commit's
 448 * parent list, if we are maintaining the per-parent treesame[] decoration.
 449 * This does not recalculate the master TREESAME flag - update_treesame()
 450 * should be called to update it after a sequence of treesame[] modifications
 451 * that may have affected it.
 452 */
 453static int compact_treesame(struct rev_info *revs, struct commit *commit, unsigned nth_parent)
 454{
 455        struct treesame_state *st;
 456        int old_same;
 457
 458        if (!commit->parents) {
 459                /*
 460                 * Have just removed the only parent from a non-merge.
 461                 * Different handling, as we lack decoration.
 462                 */
 463                if (nth_parent != 0)
 464                        die("compact_treesame %u", nth_parent);
 465                old_same = !!(commit->object.flags & TREESAME);
 466                if (rev_same_tree_as_empty(revs, commit))
 467                        commit->object.flags |= TREESAME;
 468                else
 469                        commit->object.flags &= ~TREESAME;
 470                return old_same;
 471        }
 472
 473        st = lookup_decoration(&revs->treesame, &commit->object);
 474        if (!st || nth_parent >= st->nparents)
 475                die("compact_treesame %u", nth_parent);
 476
 477        old_same = st->treesame[nth_parent];
 478        memmove(st->treesame + nth_parent,
 479                st->treesame + nth_parent + 1,
 480                st->nparents - nth_parent - 1);
 481
 482        /*
 483         * If we've just become a non-merge commit, update TREESAME
 484         * immediately, and remove the no-longer-needed decoration.
 485         * If still a merge, defer update until update_treesame().
 486         */
 487        if (--st->nparents == 1) {
 488                if (commit->parents->next)
 489                        die("compact_treesame parents mismatch");
 490                if (st->treesame[0] && revs->dense)
 491                        commit->object.flags |= TREESAME;
 492                else
 493                        commit->object.flags &= ~TREESAME;
 494                free(add_decoration(&revs->treesame, &commit->object, NULL));
 495        }
 496
 497        return old_same;
 498}
 499
 500static unsigned update_treesame(struct rev_info *revs, struct commit *commit)
 501{
 502        if (commit->parents && commit->parents->next) {
 503                unsigned n;
 504                struct treesame_state *st;
 505
 506                st = lookup_decoration(&revs->treesame, &commit->object);
 507                if (!st)
 508                        die("update_treesame %s", sha1_to_hex(commit->object.sha1));
 509                commit->object.flags |= TREESAME;
 510                for (n = 0; n < st->nparents; n++) {
 511                        if (!st->treesame[n]) {
 512                                commit->object.flags &= ~TREESAME;
 513                                break;
 514                        }
 515                }
 516        }
 517
 518        return commit->object.flags & TREESAME;
 519}
 520
 521static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 522{
 523        struct commit_list **pp, *parent;
 524        struct treesame_state *ts = NULL;
 525        int tree_changed = 0, nth_parent;
 526
 527        /*
 528         * If we don't do pruning, everything is interesting
 529         */
 530        if (!revs->prune)
 531                return;
 532
 533        if (!commit->tree)
 534                return;
 535
 536        if (!commit->parents) {
 537                if (rev_same_tree_as_empty(revs, commit))
 538                        commit->object.flags |= TREESAME;
 539                return;
 540        }
 541
 542        /*
 543         * Normal non-merge commit? If we don't want to make the
 544         * history dense, we consider it always to be a change..
 545         */
 546        if (!revs->dense && !commit->parents->next)
 547                return;
 548
 549        for (pp = &commit->parents, nth_parent = 0;
 550             (parent = *pp) != NULL;
 551             pp = &parent->next, nth_parent++) {
 552                struct commit *p = parent->item;
 553
 554                if (nth_parent == 1) {
 555                        /*
 556                         * This our second loop iteration - so we now know
 557                         * we're dealing with a merge.
 558                         *
 559                         * Do not compare with later parents when we care only about
 560                         * the first parent chain, in order to avoid derailing the
 561                         * traversal to follow a side branch that brought everything
 562                         * in the path we are limited to by the pathspec.
 563                         */
 564                        if (revs->first_parent_only)
 565                                break;
 566                        /*
 567                         * If this will remain a potentially-simplifiable
 568                         * merge, remember per-parent treesame if needed.
 569                         * Initialise the array with the comparison from our
 570                         * first iteration.
 571                         */
 572                        if (revs->treesame.name &&
 573                            !revs->simplify_history &&
 574                            !(commit->object.flags & UNINTERESTING)) {
 575                                ts = initialise_treesame(revs, commit);
 576                                if (!tree_changed)
 577                                        ts->treesame[0] = 1;
 578                        }
 579                }
 580                if (parse_commit(p) < 0)
 581                        die("cannot simplify commit %s (because of %s)",
 582                            sha1_to_hex(commit->object.sha1),
 583                            sha1_to_hex(p->object.sha1));
 584                switch (rev_compare_tree(revs, p, commit)) {
 585                case REV_TREE_SAME:
 586                        if (!revs->simplify_history || (p->object.flags & UNINTERESTING)) {
 587                                /* Even if a merge with an uninteresting
 588                                 * side branch brought the entire change
 589                                 * we are interested in, we do not want
 590                                 * to lose the other branches of this
 591                                 * merge, so we just keep going.
 592                                 */
 593                                if (ts)
 594                                        ts->treesame[nth_parent] = 1;
 595                                continue;
 596                        }
 597                        parent->next = NULL;
 598                        commit->parents = parent;
 599                        commit->object.flags |= TREESAME;
 600                        return;
 601
 602                case REV_TREE_NEW:
 603                        if (revs->remove_empty_trees &&
 604                            rev_same_tree_as_empty(revs, p)) {
 605                                /* We are adding all the specified
 606                                 * paths from this parent, so the
 607                                 * history beyond this parent is not
 608                                 * interesting.  Remove its parents
 609                                 * (they are grandparents for us).
 610                                 * IOW, we pretend this parent is a
 611                                 * "root" commit.
 612                                 */
 613                                if (parse_commit(p) < 0)
 614                                        die("cannot simplify commit %s (invalid %s)",
 615                                            sha1_to_hex(commit->object.sha1),
 616                                            sha1_to_hex(p->object.sha1));
 617                                p->parents = NULL;
 618                        }
 619                /* fallthrough */
 620                case REV_TREE_OLD:
 621                case REV_TREE_DIFFERENT:
 622                        tree_changed = 1;
 623                        continue;
 624                }
 625                die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
 626        }
 627        if (tree_changed)
 628                return;
 629        commit->object.flags |= TREESAME;
 630}
 631
 632static void commit_list_insert_by_date_cached(struct commit *p, struct commit_list **head,
 633                    struct commit_list *cached_base, struct commit_list **cache)
 634{
 635        struct commit_list *new_entry;
 636
 637        if (cached_base && p->date < cached_base->item->date)
 638                new_entry = commit_list_insert_by_date(p, &cached_base->next);
 639        else
 640                new_entry = commit_list_insert_by_date(p, head);
 641
 642        if (cache && (!*cache || p->date < (*cache)->item->date))
 643                *cache = new_entry;
 644}
 645
 646static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
 647                    struct commit_list **list, struct commit_list **cache_ptr)
 648{
 649        struct commit_list *parent = commit->parents;
 650        unsigned left_flag;
 651        struct commit_list *cached_base = cache_ptr ? *cache_ptr : NULL;
 652
 653        if (commit->object.flags & ADDED)
 654                return 0;
 655        commit->object.flags |= ADDED;
 656
 657        /*
 658         * If the commit is uninteresting, don't try to
 659         * prune parents - we want the maximal uninteresting
 660         * set.
 661         *
 662         * Normally we haven't parsed the parent
 663         * yet, so we won't have a parent of a parent
 664         * here. However, it may turn out that we've
 665         * reached this commit some other way (where it
 666         * wasn't uninteresting), in which case we need
 667         * to mark its parents recursively too..
 668         */
 669        if (commit->object.flags & UNINTERESTING) {
 670                while (parent) {
 671                        struct commit *p = parent->item;
 672                        parent = parent->next;
 673                        if (p)
 674                                p->object.flags |= UNINTERESTING;
 675                        if (parse_commit(p) < 0)
 676                                continue;
 677                        if (p->parents)
 678                                mark_parents_uninteresting(p);
 679                        if (p->object.flags & SEEN)
 680                                continue;
 681                        p->object.flags |= SEEN;
 682                        commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
 683                }
 684                return 0;
 685        }
 686
 687        /*
 688         * Ok, the commit wasn't uninteresting. Try to
 689         * simplify the commit history and find the parent
 690         * that has no differences in the path set if one exists.
 691         */
 692        try_to_simplify_commit(revs, commit);
 693
 694        if (revs->no_walk)
 695                return 0;
 696
 697        left_flag = (commit->object.flags & SYMMETRIC_LEFT);
 698
 699        for (parent = commit->parents; parent; parent = parent->next) {
 700                struct commit *p = parent->item;
 701
 702                if (parse_commit(p) < 0)
 703                        return -1;
 704                if (revs->show_source && !p->util)
 705                        p->util = commit->util;
 706                p->object.flags |= left_flag;
 707                if (!(p->object.flags & SEEN)) {
 708                        p->object.flags |= SEEN;
 709                        commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
 710                }
 711                if (revs->first_parent_only)
 712                        break;
 713        }
 714        return 0;
 715}
 716
 717static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
 718{
 719        struct commit_list *p;
 720        int left_count = 0, right_count = 0;
 721        int left_first;
 722        struct patch_ids ids;
 723        unsigned cherry_flag;
 724
 725        /* First count the commits on the left and on the right */
 726        for (p = list; p; p = p->next) {
 727                struct commit *commit = p->item;
 728                unsigned flags = commit->object.flags;
 729                if (flags & BOUNDARY)
 730                        ;
 731                else if (flags & SYMMETRIC_LEFT)
 732                        left_count++;
 733                else
 734                        right_count++;
 735        }
 736
 737        if (!left_count || !right_count)
 738                return;
 739
 740        left_first = left_count < right_count;
 741        init_patch_ids(&ids);
 742        ids.diffopts.pathspec = revs->diffopt.pathspec;
 743
 744        /* Compute patch-ids for one side */
 745        for (p = list; p; p = p->next) {
 746                struct commit *commit = p->item;
 747                unsigned flags = commit->object.flags;
 748
 749                if (flags & BOUNDARY)
 750                        continue;
 751                /*
 752                 * If we have fewer left, left_first is set and we omit
 753                 * commits on the right branch in this loop.  If we have
 754                 * fewer right, we skip the left ones.
 755                 */
 756                if (left_first != !!(flags & SYMMETRIC_LEFT))
 757                        continue;
 758                commit->util = add_commit_patch_id(commit, &ids);
 759        }
 760
 761        /* either cherry_mark or cherry_pick are true */
 762        cherry_flag = revs->cherry_mark ? PATCHSAME : SHOWN;
 763
 764        /* Check the other side */
 765        for (p = list; p; p = p->next) {
 766                struct commit *commit = p->item;
 767                struct patch_id *id;
 768                unsigned flags = commit->object.flags;
 769
 770                if (flags & BOUNDARY)
 771                        continue;
 772                /*
 773                 * If we have fewer left, left_first is set and we omit
 774                 * commits on the left branch in this loop.
 775                 */
 776                if (left_first == !!(flags & SYMMETRIC_LEFT))
 777                        continue;
 778
 779                /*
 780                 * Have we seen the same patch id?
 781                 */
 782                id = has_commit_patch_id(commit, &ids);
 783                if (!id)
 784                        continue;
 785                id->seen = 1;
 786                commit->object.flags |= cherry_flag;
 787        }
 788
 789        /* Now check the original side for seen ones */
 790        for (p = list; p; p = p->next) {
 791                struct commit *commit = p->item;
 792                struct patch_id *ent;
 793
 794                ent = commit->util;
 795                if (!ent)
 796                        continue;
 797                if (ent->seen)
 798                        commit->object.flags |= cherry_flag;
 799                commit->util = NULL;
 800        }
 801
 802        free_patch_ids(&ids);
 803}
 804
 805/* How many extra uninteresting commits we want to see.. */
 806#define SLOP 5
 807
 808static int still_interesting(struct commit_list *src, unsigned long date, int slop)
 809{
 810        /*
 811         * No source list at all? We're definitely done..
 812         */
 813        if (!src)
 814                return 0;
 815
 816        /*
 817         * Does the destination list contain entries with a date
 818         * before the source list? Definitely _not_ done.
 819         */
 820        if (date <= src->item->date)
 821                return SLOP;
 822
 823        /*
 824         * Does the source list still have interesting commits in
 825         * it? Definitely not done..
 826         */
 827        if (!everybody_uninteresting(src))
 828                return SLOP;
 829
 830        /* Ok, we're closing in.. */
 831        return slop-1;
 832}
 833
 834/*
 835 * "rev-list --ancestry-path A..B" computes commits that are ancestors
 836 * of B but not ancestors of A but further limits the result to those
 837 * that are descendants of A.  This takes the list of bottom commits and
 838 * the result of "A..B" without --ancestry-path, and limits the latter
 839 * further to the ones that can reach one of the commits in "bottom".
 840 */
 841static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *list)
 842{
 843        struct commit_list *p;
 844        struct commit_list *rlist = NULL;
 845        int made_progress;
 846
 847        /*
 848         * Reverse the list so that it will be likely that we would
 849         * process parents before children.
 850         */
 851        for (p = list; p; p = p->next)
 852                commit_list_insert(p->item, &rlist);
 853
 854        for (p = bottom; p; p = p->next)
 855                p->item->object.flags |= TMP_MARK;
 856
 857        /*
 858         * Mark the ones that can reach bottom commits in "list",
 859         * in a bottom-up fashion.
 860         */
 861        do {
 862                made_progress = 0;
 863                for (p = rlist; p; p = p->next) {
 864                        struct commit *c = p->item;
 865                        struct commit_list *parents;
 866                        if (c->object.flags & (TMP_MARK | UNINTERESTING))
 867                                continue;
 868                        for (parents = c->parents;
 869                             parents;
 870                             parents = parents->next) {
 871                                if (!(parents->item->object.flags & TMP_MARK))
 872                                        continue;
 873                                c->object.flags |= TMP_MARK;
 874                                made_progress = 1;
 875                                break;
 876                        }
 877                }
 878        } while (made_progress);
 879
 880        /*
 881         * NEEDSWORK: decide if we want to remove parents that are
 882         * not marked with TMP_MARK from commit->parents for commits
 883         * in the resulting list.  We may not want to do that, though.
 884         */
 885
 886        /*
 887         * The ones that are not marked with TMP_MARK are uninteresting
 888         */
 889        for (p = list; p; p = p->next) {
 890                struct commit *c = p->item;
 891                if (c->object.flags & TMP_MARK)
 892                        continue;
 893                c->object.flags |= UNINTERESTING;
 894        }
 895
 896        /* We are done with the TMP_MARK */
 897        for (p = list; p; p = p->next)
 898                p->item->object.flags &= ~TMP_MARK;
 899        for (p = bottom; p; p = p->next)
 900                p->item->object.flags &= ~TMP_MARK;
 901        free_commit_list(rlist);
 902}
 903
 904/*
 905 * Before walking the history, keep the set of "negative" refs the
 906 * caller has asked to exclude.
 907 *
 908 * This is used to compute "rev-list --ancestry-path A..B", as we need
 909 * to filter the result of "A..B" further to the ones that can actually
 910 * reach A.
 911 */
 912static struct commit_list *collect_bottom_commits(struct commit_list *list)
 913{
 914        struct commit_list *elem, *bottom = NULL;
 915        for (elem = list; elem; elem = elem->next)
 916                if (elem->item->object.flags & BOTTOM)
 917                        commit_list_insert(elem->item, &bottom);
 918        return bottom;
 919}
 920
 921/* Assumes either left_only or right_only is set */
 922static void limit_left_right(struct commit_list *list, struct rev_info *revs)
 923{
 924        struct commit_list *p;
 925
 926        for (p = list; p; p = p->next) {
 927                struct commit *commit = p->item;
 928
 929                if (revs->right_only) {
 930                        if (commit->object.flags & SYMMETRIC_LEFT)
 931                                commit->object.flags |= SHOWN;
 932                } else  /* revs->left_only is set */
 933                        if (!(commit->object.flags & SYMMETRIC_LEFT))
 934                                commit->object.flags |= SHOWN;
 935        }
 936}
 937
 938static int limit_list(struct rev_info *revs)
 939{
 940        int slop = SLOP;
 941        unsigned long date = ~0ul;
 942        struct commit_list *list = revs->commits;
 943        struct commit_list *newlist = NULL;
 944        struct commit_list **p = &newlist;
 945        struct commit_list *bottom = NULL;
 946
 947        if (revs->ancestry_path) {
 948                bottom = collect_bottom_commits(list);
 949                if (!bottom)
 950                        die("--ancestry-path given but there are no bottom commits");
 951        }
 952
 953        while (list) {
 954                struct commit_list *entry = list;
 955                struct commit *commit = list->item;
 956                struct object *obj = &commit->object;
 957                show_early_output_fn_t show;
 958
 959                list = list->next;
 960                free(entry);
 961
 962                if (revs->max_age != -1 && (commit->date < revs->max_age))
 963                        obj->flags |= UNINTERESTING;
 964                if (add_parents_to_list(revs, commit, &list, NULL) < 0)
 965                        return -1;
 966                if (obj->flags & UNINTERESTING) {
 967                        mark_parents_uninteresting(commit);
 968                        if (revs->show_all)
 969                                p = &commit_list_insert(commit, p)->next;
 970                        slop = still_interesting(list, date, slop);
 971                        if (slop)
 972                                continue;
 973                        /* If showing all, add the whole pending list to the end */
 974                        if (revs->show_all)
 975                                *p = list;
 976                        break;
 977                }
 978                if (revs->min_age != -1 && (commit->date > revs->min_age))
 979                        continue;
 980                date = commit->date;
 981                p = &commit_list_insert(commit, p)->next;
 982
 983                show = show_early_output;
 984                if (!show)
 985                        continue;
 986
 987                show(revs, newlist);
 988                show_early_output = NULL;
 989        }
 990        if (revs->cherry_pick || revs->cherry_mark)
 991                cherry_pick_list(newlist, revs);
 992
 993        if (revs->left_only || revs->right_only)
 994                limit_left_right(newlist, revs);
 995
 996        if (bottom) {
 997                limit_to_ancestry(bottom, newlist);
 998                free_commit_list(bottom);
 999        }
1000
1001        revs->commits = newlist;
1002        return 0;
1003}
1004
1005static void add_rev_cmdline(struct rev_info *revs,
1006                            struct object *item,
1007                            const char *name,
1008                            int whence,
1009                            unsigned flags)
1010{
1011        struct rev_cmdline_info *info = &revs->cmdline;
1012        int nr = info->nr;
1013
1014        ALLOC_GROW(info->rev, nr + 1, info->alloc);
1015        info->rev[nr].item = item;
1016        info->rev[nr].name = name;
1017        info->rev[nr].whence = whence;
1018        info->rev[nr].flags = flags;
1019        info->nr++;
1020}
1021
1022static void add_rev_cmdline_list(struct rev_info *revs,
1023                                 struct commit_list *commit_list,
1024                                 int whence,
1025                                 unsigned flags)
1026{
1027        while (commit_list) {
1028                struct object *object = &commit_list->item->object;
1029                add_rev_cmdline(revs, object, sha1_to_hex(object->sha1),
1030                                whence, flags);
1031                commit_list = commit_list->next;
1032        }
1033}
1034
1035struct all_refs_cb {
1036        int all_flags;
1037        int warned_bad_reflog;
1038        struct rev_info *all_revs;
1039        const char *name_for_errormsg;
1040};
1041
1042static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1043{
1044        struct all_refs_cb *cb = cb_data;
1045        struct object *object = get_reference(cb->all_revs, path, sha1,
1046                                              cb->all_flags);
1047        add_rev_cmdline(cb->all_revs, object, path, REV_CMD_REF, cb->all_flags);
1048        add_pending_sha1(cb->all_revs, path, sha1, cb->all_flags);
1049        return 0;
1050}
1051
1052static void init_all_refs_cb(struct all_refs_cb *cb, struct rev_info *revs,
1053        unsigned flags)
1054{
1055        cb->all_revs = revs;
1056        cb->all_flags = flags;
1057}
1058
1059static void handle_refs(const char *submodule, struct rev_info *revs, unsigned flags,
1060                int (*for_each)(const char *, each_ref_fn, void *))
1061{
1062        struct all_refs_cb cb;
1063        init_all_refs_cb(&cb, revs, flags);
1064        for_each(submodule, handle_one_ref, &cb);
1065}
1066
1067static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
1068{
1069        struct all_refs_cb *cb = cb_data;
1070        if (!is_null_sha1(sha1)) {
1071                struct object *o = parse_object(sha1);
1072                if (o) {
1073                        o->flags |= cb->all_flags;
1074                        /* ??? CMDLINEFLAGS ??? */
1075                        add_pending_object(cb->all_revs, o, "");
1076                }
1077                else if (!cb->warned_bad_reflog) {
1078                        warning("reflog of '%s' references pruned commits",
1079                                cb->name_for_errormsg);
1080                        cb->warned_bad_reflog = 1;
1081                }
1082        }
1083}
1084
1085static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
1086                const char *email, unsigned long timestamp, int tz,
1087                const char *message, void *cb_data)
1088{
1089        handle_one_reflog_commit(osha1, cb_data);
1090        handle_one_reflog_commit(nsha1, cb_data);
1091        return 0;
1092}
1093
1094static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1095{
1096        struct all_refs_cb *cb = cb_data;
1097        cb->warned_bad_reflog = 0;
1098        cb->name_for_errormsg = path;
1099        for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
1100        return 0;
1101}
1102
1103static void handle_reflog(struct rev_info *revs, unsigned flags)
1104{
1105        struct all_refs_cb cb;
1106        cb.all_revs = revs;
1107        cb.all_flags = flags;
1108        for_each_reflog(handle_one_reflog, &cb);
1109}
1110
1111static int add_parents_only(struct rev_info *revs, const char *arg_, int flags)
1112{
1113        unsigned char sha1[20];
1114        struct object *it;
1115        struct commit *commit;
1116        struct commit_list *parents;
1117        const char *arg = arg_;
1118
1119        if (*arg == '^') {
1120                flags ^= UNINTERESTING | BOTTOM;
1121                arg++;
1122        }
1123        if (get_sha1_committish(arg, sha1))
1124                return 0;
1125        while (1) {
1126                it = get_reference(revs, arg, sha1, 0);
1127                if (!it && revs->ignore_missing)
1128                        return 0;
1129                if (it->type != OBJ_TAG)
1130                        break;
1131                if (!((struct tag*)it)->tagged)
1132                        return 0;
1133                hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
1134        }
1135        if (it->type != OBJ_COMMIT)
1136                return 0;
1137        commit = (struct commit *)it;
1138        for (parents = commit->parents; parents; parents = parents->next) {
1139                it = &parents->item->object;
1140                it->flags |= flags;
1141                add_rev_cmdline(revs, it, arg_, REV_CMD_PARENTS_ONLY, flags);
1142                add_pending_object(revs, it, arg);
1143        }
1144        return 1;
1145}
1146
1147void init_revisions(struct rev_info *revs, const char *prefix)
1148{
1149        memset(revs, 0, sizeof(*revs));
1150
1151        revs->abbrev = DEFAULT_ABBREV;
1152        revs->ignore_merges = 1;
1153        revs->simplify_history = 1;
1154        DIFF_OPT_SET(&revs->pruning, RECURSIVE);
1155        DIFF_OPT_SET(&revs->pruning, QUICK);
1156        revs->pruning.add_remove = file_add_remove;
1157        revs->pruning.change = file_change;
1158        revs->lifo = 1;
1159        revs->dense = 1;
1160        revs->prefix = prefix;
1161        revs->max_age = -1;
1162        revs->min_age = -1;
1163        revs->skip_count = -1;
1164        revs->max_count = -1;
1165        revs->max_parents = -1;
1166
1167        revs->commit_format = CMIT_FMT_DEFAULT;
1168
1169        init_grep_defaults();
1170        grep_init(&revs->grep_filter, prefix);
1171        revs->grep_filter.status_only = 1;
1172        revs->grep_filter.regflags = REG_NEWLINE;
1173
1174        diff_setup(&revs->diffopt);
1175        if (prefix && !revs->diffopt.prefix) {
1176                revs->diffopt.prefix = prefix;
1177                revs->diffopt.prefix_length = strlen(prefix);
1178        }
1179
1180        revs->notes_opt.use_default_notes = -1;
1181}
1182
1183static void add_pending_commit_list(struct rev_info *revs,
1184                                    struct commit_list *commit_list,
1185                                    unsigned int flags)
1186{
1187        while (commit_list) {
1188                struct object *object = &commit_list->item->object;
1189                object->flags |= flags;
1190                add_pending_object(revs, object, sha1_to_hex(object->sha1));
1191                commit_list = commit_list->next;
1192        }
1193}
1194
1195static void prepare_show_merge(struct rev_info *revs)
1196{
1197        struct commit_list *bases;
1198        struct commit *head, *other;
1199        unsigned char sha1[20];
1200        const char **prune = NULL;
1201        int i, prune_num = 1; /* counting terminating NULL */
1202
1203        if (get_sha1("HEAD", sha1))
1204                die("--merge without HEAD?");
1205        head = lookup_commit_or_die(sha1, "HEAD");
1206        if (get_sha1("MERGE_HEAD", sha1))
1207                die("--merge without MERGE_HEAD?");
1208        other = lookup_commit_or_die(sha1, "MERGE_HEAD");
1209        add_pending_object(revs, &head->object, "HEAD");
1210        add_pending_object(revs, &other->object, "MERGE_HEAD");
1211        bases = get_merge_bases(head, other, 1);
1212        add_rev_cmdline_list(revs, bases, REV_CMD_MERGE_BASE, UNINTERESTING | BOTTOM);
1213        add_pending_commit_list(revs, bases, UNINTERESTING | BOTTOM);
1214        free_commit_list(bases);
1215        head->object.flags |= SYMMETRIC_LEFT;
1216
1217        if (!active_nr)
1218                read_cache();
1219        for (i = 0; i < active_nr; i++) {
1220                struct cache_entry *ce = active_cache[i];
1221                if (!ce_stage(ce))
1222                        continue;
1223                if (ce_path_match(ce, &revs->prune_data)) {
1224                        prune_num++;
1225                        prune = xrealloc(prune, sizeof(*prune) * prune_num);
1226                        prune[prune_num-2] = ce->name;
1227                        prune[prune_num-1] = NULL;
1228                }
1229                while ((i+1 < active_nr) &&
1230                       ce_same_name(ce, active_cache[i+1]))
1231                        i++;
1232        }
1233        free_pathspec(&revs->prune_data);
1234        init_pathspec(&revs->prune_data, prune);
1235        revs->limited = 1;
1236}
1237
1238int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsigned revarg_opt)
1239{
1240        struct object_context oc;
1241        char *dotdot;
1242        struct object *object;
1243        unsigned char sha1[20];
1244        int local_flags;
1245        const char *arg = arg_;
1246        int cant_be_filename = revarg_opt & REVARG_CANNOT_BE_FILENAME;
1247        unsigned get_sha1_flags = 0;
1248
1249        flags = flags & UNINTERESTING ? flags | BOTTOM : flags & ~BOTTOM;
1250
1251        dotdot = strstr(arg, "..");
1252        if (dotdot) {
1253                unsigned char from_sha1[20];
1254                const char *next = dotdot + 2;
1255                const char *this = arg;
1256                int symmetric = *next == '.';
1257                unsigned int flags_exclude = flags ^ (UNINTERESTING | BOTTOM);
1258                static const char head_by_default[] = "HEAD";
1259                unsigned int a_flags;
1260
1261                *dotdot = 0;
1262                next += symmetric;
1263
1264                if (!*next)
1265                        next = head_by_default;
1266                if (dotdot == arg)
1267                        this = head_by_default;
1268                if (this == head_by_default && next == head_by_default &&
1269                    !symmetric) {
1270                        /*
1271                         * Just ".."?  That is not a range but the
1272                         * pathspec for the parent directory.
1273                         */
1274                        if (!cant_be_filename) {
1275                                *dotdot = '.';
1276                                return -1;
1277                        }
1278                }
1279                if (!get_sha1_committish(this, from_sha1) &&
1280                    !get_sha1_committish(next, sha1)) {
1281                        struct commit *a, *b;
1282                        struct commit_list *exclude;
1283
1284                        a = lookup_commit_reference(from_sha1);
1285                        b = lookup_commit_reference(sha1);
1286                        if (!a || !b) {
1287                                if (revs->ignore_missing)
1288                                        return 0;
1289                                die(symmetric ?
1290                                    "Invalid symmetric difference expression %s...%s" :
1291                                    "Invalid revision range %s..%s",
1292                                    arg, next);
1293                        }
1294
1295                        if (!cant_be_filename) {
1296                                *dotdot = '.';
1297                                verify_non_filename(revs->prefix, arg);
1298                        }
1299
1300                        if (symmetric) {
1301                                exclude = get_merge_bases(a, b, 1);
1302                                add_rev_cmdline_list(revs, exclude,
1303                                                     REV_CMD_MERGE_BASE,
1304                                                     flags_exclude);
1305                                add_pending_commit_list(revs, exclude,
1306                                                        flags_exclude);
1307                                free_commit_list(exclude);
1308                                a_flags = flags | SYMMETRIC_LEFT;
1309                        } else
1310                                a_flags = flags_exclude;
1311                        a->object.flags |= a_flags;
1312                        b->object.flags |= flags;
1313                        add_rev_cmdline(revs, &a->object, this,
1314                                        REV_CMD_LEFT, a_flags);
1315                        add_rev_cmdline(revs, &b->object, next,
1316                                        REV_CMD_RIGHT, flags);
1317                        add_pending_object(revs, &a->object, this);
1318                        add_pending_object(revs, &b->object, next);
1319                        return 0;
1320                }
1321                *dotdot = '.';
1322        }
1323        dotdot = strstr(arg, "^@");
1324        if (dotdot && !dotdot[2]) {
1325                *dotdot = 0;
1326                if (add_parents_only(revs, arg, flags))
1327                        return 0;
1328                *dotdot = '^';
1329        }
1330        dotdot = strstr(arg, "^!");
1331        if (dotdot && !dotdot[2]) {
1332                *dotdot = 0;
1333                if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM)))
1334                        *dotdot = '^';
1335        }
1336
1337        local_flags = 0;
1338        if (*arg == '^') {
1339                local_flags = UNINTERESTING | BOTTOM;
1340                arg++;
1341        }
1342
1343        if (revarg_opt & REVARG_COMMITTISH)
1344                get_sha1_flags = GET_SHA1_COMMITTISH;
1345
1346        if (get_sha1_with_context(arg, get_sha1_flags, sha1, &oc))
1347                return revs->ignore_missing ? 0 : -1;
1348        if (!cant_be_filename)
1349                verify_non_filename(revs->prefix, arg);
1350        object = get_reference(revs, arg, sha1, flags ^ local_flags);
1351        add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
1352        add_pending_object_with_mode(revs, object, arg, oc.mode);
1353        return 0;
1354}
1355
1356struct cmdline_pathspec {
1357        int alloc;
1358        int nr;
1359        const char **path;
1360};
1361
1362static void append_prune_data(struct cmdline_pathspec *prune, const char **av)
1363{
1364        while (*av) {
1365                ALLOC_GROW(prune->path, prune->nr+1, prune->alloc);
1366                prune->path[prune->nr++] = *(av++);
1367        }
1368}
1369
1370static void read_pathspec_from_stdin(struct rev_info *revs, struct strbuf *sb,
1371                                     struct cmdline_pathspec *prune)
1372{
1373        while (strbuf_getwholeline(sb, stdin, '\n') != EOF) {
1374                int len = sb->len;
1375                if (len && sb->buf[len - 1] == '\n')
1376                        sb->buf[--len] = '\0';
1377                ALLOC_GROW(prune->path, prune->nr+1, prune->alloc);
1378                prune->path[prune->nr++] = xstrdup(sb->buf);
1379        }
1380}
1381
1382static void read_revisions_from_stdin(struct rev_info *revs,
1383                                      struct cmdline_pathspec *prune)
1384{
1385        struct strbuf sb;
1386        int seen_dashdash = 0;
1387
1388        strbuf_init(&sb, 1000);
1389        while (strbuf_getwholeline(&sb, stdin, '\n') != EOF) {
1390                int len = sb.len;
1391                if (len && sb.buf[len - 1] == '\n')
1392                        sb.buf[--len] = '\0';
1393                if (!len)
1394                        break;
1395                if (sb.buf[0] == '-') {
1396                        if (len == 2 && sb.buf[1] == '-') {
1397                                seen_dashdash = 1;
1398                                break;
1399                        }
1400                        die("options not supported in --stdin mode");
1401                }
1402                if (handle_revision_arg(xstrdup(sb.buf), revs, 0,
1403                                        REVARG_CANNOT_BE_FILENAME))
1404                        die("bad revision '%s'", sb.buf);
1405        }
1406        if (seen_dashdash)
1407                read_pathspec_from_stdin(revs, &sb, prune);
1408        strbuf_release(&sb);
1409}
1410
1411static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
1412{
1413        append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
1414}
1415
1416static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
1417{
1418        append_header_grep_pattern(&revs->grep_filter, field, pattern);
1419}
1420
1421static void add_message_grep(struct rev_info *revs, const char *pattern)
1422{
1423        add_grep(revs, pattern, GREP_PATTERN_BODY);
1424}
1425
1426static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
1427                               int *unkc, const char **unkv)
1428{
1429        const char *arg = argv[0];
1430        const char *optarg;
1431        int argcount;
1432
1433        /* pseudo revision arguments */
1434        if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
1435            !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
1436            !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
1437            !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
1438            !strcmp(arg, "--bisect") || !prefixcmp(arg, "--glob=") ||
1439            !prefixcmp(arg, "--branches=") || !prefixcmp(arg, "--tags=") ||
1440            !prefixcmp(arg, "--remotes=") || !prefixcmp(arg, "--no-walk="))
1441        {
1442                unkv[(*unkc)++] = arg;
1443                return 1;
1444        }
1445
1446        if ((argcount = parse_long_opt("max-count", argv, &optarg))) {
1447                revs->max_count = atoi(optarg);
1448                revs->no_walk = 0;
1449                return argcount;
1450        } else if ((argcount = parse_long_opt("skip", argv, &optarg))) {
1451                revs->skip_count = atoi(optarg);
1452                return argcount;
1453        } else if ((*arg == '-') && isdigit(arg[1])) {
1454        /* accept -<digit>, like traditional "head" */
1455                revs->max_count = atoi(arg + 1);
1456                revs->no_walk = 0;
1457        } else if (!strcmp(arg, "-n")) {
1458                if (argc <= 1)
1459                        return error("-n requires an argument");
1460                revs->max_count = atoi(argv[1]);
1461                revs->no_walk = 0;
1462                return 2;
1463        } else if (!prefixcmp(arg, "-n")) {
1464                revs->max_count = atoi(arg + 2);
1465                revs->no_walk = 0;
1466        } else if ((argcount = parse_long_opt("max-age", argv, &optarg))) {
1467                revs->max_age = atoi(optarg);
1468                return argcount;
1469        } else if ((argcount = parse_long_opt("since", argv, &optarg))) {
1470                revs->max_age = approxidate(optarg);
1471                return argcount;
1472        } else if ((argcount = parse_long_opt("after", argv, &optarg))) {
1473                revs->max_age = approxidate(optarg);
1474                return argcount;
1475        } else if ((argcount = parse_long_opt("min-age", argv, &optarg))) {
1476                revs->min_age = atoi(optarg);
1477                return argcount;
1478        } else if ((argcount = parse_long_opt("before", argv, &optarg))) {
1479                revs->min_age = approxidate(optarg);
1480                return argcount;
1481        } else if ((argcount = parse_long_opt("until", argv, &optarg))) {
1482                revs->min_age = approxidate(optarg);
1483                return argcount;
1484        } else if (!strcmp(arg, "--first-parent")) {
1485                revs->first_parent_only = 1;
1486        } else if (!strcmp(arg, "--ancestry-path")) {
1487                revs->ancestry_path = 1;
1488                revs->simplify_history = 0;
1489                revs->limited = 1;
1490        } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
1491                init_reflog_walk(&revs->reflog_info);
1492        } else if (!strcmp(arg, "--default")) {
1493                if (argc <= 1)
1494                        return error("bad --default argument");
1495                revs->def = argv[1];
1496                return 2;
1497        } else if (!strcmp(arg, "--merge")) {
1498                revs->show_merge = 1;
1499        } else if (!strcmp(arg, "--topo-order")) {
1500                revs->lifo = 1;
1501                revs->topo_order = 1;
1502        } else if (!strcmp(arg, "--simplify-merges")) {
1503                revs->simplify_merges = 1;
1504                revs->topo_order = 1;
1505                revs->rewrite_parents = 1;
1506                revs->simplify_history = 0;
1507                revs->limited = 1;
1508        } else if (!strcmp(arg, "--simplify-by-decoration")) {
1509                revs->simplify_merges = 1;
1510                revs->topo_order = 1;
1511                revs->rewrite_parents = 1;
1512                revs->simplify_history = 0;
1513                revs->simplify_by_decoration = 1;
1514                revs->limited = 1;
1515                revs->prune = 1;
1516                load_ref_decorations(DECORATE_SHORT_REFS);
1517        } else if (!strcmp(arg, "--date-order")) {
1518                revs->lifo = 0;
1519                revs->topo_order = 1;
1520        } else if (!prefixcmp(arg, "--early-output")) {
1521                int count = 100;
1522                switch (arg[14]) {
1523                case '=':
1524                        count = atoi(arg+15);
1525                        /* Fallthrough */
1526                case 0:
1527                        revs->topo_order = 1;
1528                       revs->early_output = count;
1529                }
1530        } else if (!strcmp(arg, "--parents")) {
1531                revs->rewrite_parents = 1;
1532                revs->print_parents = 1;
1533        } else if (!strcmp(arg, "--dense")) {
1534                revs->dense = 1;
1535        } else if (!strcmp(arg, "--sparse")) {
1536                revs->dense = 0;
1537        } else if (!strcmp(arg, "--show-all")) {
1538                revs->show_all = 1;
1539        } else if (!strcmp(arg, "--remove-empty")) {
1540                revs->remove_empty_trees = 1;
1541        } else if (!strcmp(arg, "--merges")) {
1542                revs->min_parents = 2;
1543        } else if (!strcmp(arg, "--no-merges")) {
1544                revs->max_parents = 1;
1545        } else if (!prefixcmp(arg, "--min-parents=")) {
1546                revs->min_parents = atoi(arg+14);
1547        } else if (!prefixcmp(arg, "--no-min-parents")) {
1548                revs->min_parents = 0;
1549        } else if (!prefixcmp(arg, "--max-parents=")) {
1550                revs->max_parents = atoi(arg+14);
1551        } else if (!prefixcmp(arg, "--no-max-parents")) {
1552                revs->max_parents = -1;
1553        } else if (!strcmp(arg, "--boundary")) {
1554                revs->boundary = 1;
1555        } else if (!strcmp(arg, "--left-right")) {
1556                revs->left_right = 1;
1557        } else if (!strcmp(arg, "--left-only")) {
1558                if (revs->right_only)
1559                        die("--left-only is incompatible with --right-only"
1560                            " or --cherry");
1561                revs->left_only = 1;
1562        } else if (!strcmp(arg, "--right-only")) {
1563                if (revs->left_only)
1564                        die("--right-only is incompatible with --left-only");
1565                revs->right_only = 1;
1566        } else if (!strcmp(arg, "--cherry")) {
1567                if (revs->left_only)
1568                        die("--cherry is incompatible with --left-only");
1569                revs->cherry_mark = 1;
1570                revs->right_only = 1;
1571                revs->max_parents = 1;
1572                revs->limited = 1;
1573        } else if (!strcmp(arg, "--count")) {
1574                revs->count = 1;
1575        } else if (!strcmp(arg, "--cherry-mark")) {
1576                if (revs->cherry_pick)
1577                        die("--cherry-mark is incompatible with --cherry-pick");
1578                revs->cherry_mark = 1;
1579                revs->limited = 1; /* needs limit_list() */
1580        } else if (!strcmp(arg, "--cherry-pick")) {
1581                if (revs->cherry_mark)
1582                        die("--cherry-pick is incompatible with --cherry-mark");
1583                revs->cherry_pick = 1;
1584                revs->limited = 1;
1585        } else if (!strcmp(arg, "--objects")) {
1586                revs->tag_objects = 1;
1587                revs->tree_objects = 1;
1588                revs->blob_objects = 1;
1589        } else if (!strcmp(arg, "--objects-edge")) {
1590                revs->tag_objects = 1;
1591                revs->tree_objects = 1;
1592                revs->blob_objects = 1;
1593                revs->edge_hint = 1;
1594        } else if (!strcmp(arg, "--verify-objects")) {
1595                revs->tag_objects = 1;
1596                revs->tree_objects = 1;
1597                revs->blob_objects = 1;
1598                revs->verify_objects = 1;
1599        } else if (!strcmp(arg, "--unpacked")) {
1600                revs->unpacked = 1;
1601        } else if (!prefixcmp(arg, "--unpacked=")) {
1602                die("--unpacked=<packfile> no longer supported.");
1603        } else if (!strcmp(arg, "-r")) {
1604                revs->diff = 1;
1605                DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1606        } else if (!strcmp(arg, "-t")) {
1607                revs->diff = 1;
1608                DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1609                DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1610        } else if (!strcmp(arg, "-m")) {
1611                revs->ignore_merges = 0;
1612        } else if (!strcmp(arg, "-c")) {
1613                revs->diff = 1;
1614                revs->dense_combined_merges = 0;
1615                revs->combine_merges = 1;
1616        } else if (!strcmp(arg, "--cc")) {
1617                revs->diff = 1;
1618                revs->dense_combined_merges = 1;
1619                revs->combine_merges = 1;
1620        } else if (!strcmp(arg, "-v")) {
1621                revs->verbose_header = 1;
1622        } else if (!strcmp(arg, "--pretty")) {
1623                revs->verbose_header = 1;
1624                revs->pretty_given = 1;
1625                get_commit_format(arg+8, revs);
1626        } else if (!prefixcmp(arg, "--pretty=") || !prefixcmp(arg, "--format=")) {
1627                /*
1628                 * Detached form ("--pretty X" as opposed to "--pretty=X")
1629                 * not allowed, since the argument is optional.
1630                 */
1631                revs->verbose_header = 1;
1632                revs->pretty_given = 1;
1633                get_commit_format(arg+9, revs);
1634        } else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
1635                revs->show_notes = 1;
1636                revs->show_notes_given = 1;
1637                revs->notes_opt.use_default_notes = 1;
1638        } else if (!strcmp(arg, "--show-signature")) {
1639                revs->show_signature = 1;
1640        } else if (!prefixcmp(arg, "--show-notes=") ||
1641                   !prefixcmp(arg, "--notes=")) {
1642                struct strbuf buf = STRBUF_INIT;
1643                revs->show_notes = 1;
1644                revs->show_notes_given = 1;
1645                if (!prefixcmp(arg, "--show-notes")) {
1646                        if (revs->notes_opt.use_default_notes < 0)
1647                                revs->notes_opt.use_default_notes = 1;
1648                        strbuf_addstr(&buf, arg+13);
1649                }
1650                else
1651                        strbuf_addstr(&buf, arg+8);
1652                expand_notes_ref(&buf);
1653                string_list_append(&revs->notes_opt.extra_notes_refs,
1654                                   strbuf_detach(&buf, NULL));
1655        } else if (!strcmp(arg, "--no-notes")) {
1656                revs->show_notes = 0;
1657                revs->show_notes_given = 1;
1658                revs->notes_opt.use_default_notes = -1;
1659                /* we have been strdup'ing ourselves, so trick
1660                 * string_list into free()ing strings */
1661                revs->notes_opt.extra_notes_refs.strdup_strings = 1;
1662                string_list_clear(&revs->notes_opt.extra_notes_refs, 0);
1663                revs->notes_opt.extra_notes_refs.strdup_strings = 0;
1664        } else if (!strcmp(arg, "--standard-notes")) {
1665                revs->show_notes_given = 1;
1666                revs->notes_opt.use_default_notes = 1;
1667        } else if (!strcmp(arg, "--no-standard-notes")) {
1668                revs->notes_opt.use_default_notes = 0;
1669        } else if (!strcmp(arg, "--oneline")) {
1670                revs->verbose_header = 1;
1671                get_commit_format("oneline", revs);
1672                revs->pretty_given = 1;
1673                revs->abbrev_commit = 1;
1674        } else if (!strcmp(arg, "--graph")) {
1675                revs->topo_order = 1;
1676                revs->rewrite_parents = 1;
1677                revs->graph = graph_init(revs);
1678        } else if (!strcmp(arg, "--root")) {
1679                revs->show_root_diff = 1;
1680        } else if (!strcmp(arg, "--no-commit-id")) {
1681                revs->no_commit_id = 1;
1682        } else if (!strcmp(arg, "--always")) {
1683                revs->always_show_header = 1;
1684        } else if (!strcmp(arg, "--no-abbrev")) {
1685                revs->abbrev = 0;
1686        } else if (!strcmp(arg, "--abbrev")) {
1687                revs->abbrev = DEFAULT_ABBREV;
1688        } else if (!prefixcmp(arg, "--abbrev=")) {
1689                revs->abbrev = strtoul(arg + 9, NULL, 10);
1690                if (revs->abbrev < MINIMUM_ABBREV)
1691                        revs->abbrev = MINIMUM_ABBREV;
1692                else if (revs->abbrev > 40)
1693                        revs->abbrev = 40;
1694        } else if (!strcmp(arg, "--abbrev-commit")) {
1695                revs->abbrev_commit = 1;
1696                revs->abbrev_commit_given = 1;
1697        } else if (!strcmp(arg, "--no-abbrev-commit")) {
1698                revs->abbrev_commit = 0;
1699        } else if (!strcmp(arg, "--full-diff")) {
1700                revs->diff = 1;
1701                revs->full_diff = 1;
1702        } else if (!strcmp(arg, "--full-history")) {
1703                revs->simplify_history = 0;
1704        } else if (!strcmp(arg, "--relative-date")) {
1705                revs->date_mode = DATE_RELATIVE;
1706                revs->date_mode_explicit = 1;
1707        } else if ((argcount = parse_long_opt("date", argv, &optarg))) {
1708                revs->date_mode = parse_date_format(optarg);
1709                revs->date_mode_explicit = 1;
1710                return argcount;
1711        } else if (!strcmp(arg, "--log-size")) {
1712                revs->show_log_size = 1;
1713        }
1714        /*
1715         * Grepping the commit log
1716         */
1717        else if ((argcount = parse_long_opt("author", argv, &optarg))) {
1718                add_header_grep(revs, GREP_HEADER_AUTHOR, optarg);
1719                return argcount;
1720        } else if ((argcount = parse_long_opt("committer", argv, &optarg))) {
1721                add_header_grep(revs, GREP_HEADER_COMMITTER, optarg);
1722                return argcount;
1723        } else if ((argcount = parse_long_opt("grep-reflog", argv, &optarg))) {
1724                add_header_grep(revs, GREP_HEADER_REFLOG, optarg);
1725                return argcount;
1726        } else if ((argcount = parse_long_opt("grep", argv, &optarg))) {
1727                add_message_grep(revs, optarg);
1728                return argcount;
1729        } else if (!strcmp(arg, "--grep-debug")) {
1730                revs->grep_filter.debug = 1;
1731        } else if (!strcmp(arg, "--basic-regexp")) {
1732                grep_set_pattern_type_option(GREP_PATTERN_TYPE_BRE, &revs->grep_filter);
1733        } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
1734                grep_set_pattern_type_option(GREP_PATTERN_TYPE_ERE, &revs->grep_filter);
1735        } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
1736                revs->grep_filter.regflags |= REG_ICASE;
1737                DIFF_OPT_SET(&revs->diffopt, PICKAXE_IGNORE_CASE);
1738        } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
1739                grep_set_pattern_type_option(GREP_PATTERN_TYPE_FIXED, &revs->grep_filter);
1740        } else if (!strcmp(arg, "--perl-regexp")) {
1741                grep_set_pattern_type_option(GREP_PATTERN_TYPE_PCRE, &revs->grep_filter);
1742        } else if (!strcmp(arg, "--all-match")) {
1743                revs->grep_filter.all_match = 1;
1744        } else if ((argcount = parse_long_opt("encoding", argv, &optarg))) {
1745                if (strcmp(optarg, "none"))
1746                        git_log_output_encoding = xstrdup(optarg);
1747                else
1748                        git_log_output_encoding = "";
1749                return argcount;
1750        } else if (!strcmp(arg, "--reverse")) {
1751                revs->reverse ^= 1;
1752        } else if (!strcmp(arg, "--children")) {
1753                revs->children.name = "children";
1754                revs->limited = 1;
1755        } else if (!strcmp(arg, "--ignore-missing")) {
1756                revs->ignore_missing = 1;
1757        } else {
1758                int opts = diff_opt_parse(&revs->diffopt, argv, argc);
1759                if (!opts)
1760                        unkv[(*unkc)++] = arg;
1761                return opts;
1762        }
1763
1764        return 1;
1765}
1766
1767void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
1768                        const struct option *options,
1769                        const char * const usagestr[])
1770{
1771        int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
1772                                    &ctx->cpidx, ctx->out);
1773        if (n <= 0) {
1774                error("unknown option `%s'", ctx->argv[0]);
1775                usage_with_options(usagestr, options);
1776        }
1777        ctx->argv += n;
1778        ctx->argc -= n;
1779}
1780
1781static int for_each_bad_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1782{
1783        return for_each_ref_in_submodule(submodule, "refs/bisect/bad", fn, cb_data);
1784}
1785
1786static int for_each_good_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1787{
1788        return for_each_ref_in_submodule(submodule, "refs/bisect/good", fn, cb_data);
1789}
1790
1791static int handle_revision_pseudo_opt(const char *submodule,
1792                                struct rev_info *revs,
1793                                int argc, const char **argv, int *flags)
1794{
1795        const char *arg = argv[0];
1796        const char *optarg;
1797        int argcount;
1798
1799        /*
1800         * NOTE!
1801         *
1802         * Commands like "git shortlog" will not accept the options below
1803         * unless parse_revision_opt queues them (as opposed to erroring
1804         * out).
1805         *
1806         * When implementing your new pseudo-option, remember to
1807         * register it in the list at the top of handle_revision_opt.
1808         */
1809        if (!strcmp(arg, "--all")) {
1810                handle_refs(submodule, revs, *flags, for_each_ref_submodule);
1811                handle_refs(submodule, revs, *flags, head_ref_submodule);
1812        } else if (!strcmp(arg, "--branches")) {
1813                handle_refs(submodule, revs, *flags, for_each_branch_ref_submodule);
1814        } else if (!strcmp(arg, "--bisect")) {
1815                handle_refs(submodule, revs, *flags, for_each_bad_bisect_ref);
1816                handle_refs(submodule, revs, *flags ^ (UNINTERESTING | BOTTOM), for_each_good_bisect_ref);
1817                revs->bisect = 1;
1818        } else if (!strcmp(arg, "--tags")) {
1819                handle_refs(submodule, revs, *flags, for_each_tag_ref_submodule);
1820        } else if (!strcmp(arg, "--remotes")) {
1821                handle_refs(submodule, revs, *flags, for_each_remote_ref_submodule);
1822        } else if ((argcount = parse_long_opt("glob", argv, &optarg))) {
1823                struct all_refs_cb cb;
1824                init_all_refs_cb(&cb, revs, *flags);
1825                for_each_glob_ref(handle_one_ref, optarg, &cb);
1826                return argcount;
1827        } else if (!prefixcmp(arg, "--branches=")) {
1828                struct all_refs_cb cb;
1829                init_all_refs_cb(&cb, revs, *flags);
1830                for_each_glob_ref_in(handle_one_ref, arg + 11, "refs/heads/", &cb);
1831        } else if (!prefixcmp(arg, "--tags=")) {
1832                struct all_refs_cb cb;
1833                init_all_refs_cb(&cb, revs, *flags);
1834                for_each_glob_ref_in(handle_one_ref, arg + 7, "refs/tags/", &cb);
1835        } else if (!prefixcmp(arg, "--remotes=")) {
1836                struct all_refs_cb cb;
1837                init_all_refs_cb(&cb, revs, *flags);
1838                for_each_glob_ref_in(handle_one_ref, arg + 10, "refs/remotes/", &cb);
1839        } else if (!strcmp(arg, "--reflog")) {
1840                handle_reflog(revs, *flags);
1841        } else if (!strcmp(arg, "--not")) {
1842                *flags ^= UNINTERESTING | BOTTOM;
1843        } else if (!strcmp(arg, "--no-walk")) {
1844                revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
1845        } else if (!prefixcmp(arg, "--no-walk=")) {
1846                /*
1847                 * Detached form ("--no-walk X" as opposed to "--no-walk=X")
1848                 * not allowed, since the argument is optional.
1849                 */
1850                if (!strcmp(arg + 10, "sorted"))
1851                        revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
1852                else if (!strcmp(arg + 10, "unsorted"))
1853                        revs->no_walk = REVISION_WALK_NO_WALK_UNSORTED;
1854                else
1855                        return error("invalid argument to --no-walk");
1856        } else if (!strcmp(arg, "--do-walk")) {
1857                revs->no_walk = 0;
1858        } else {
1859                return 0;
1860        }
1861
1862        return 1;
1863}
1864
1865/*
1866 * Parse revision information, filling in the "rev_info" structure,
1867 * and removing the used arguments from the argument list.
1868 *
1869 * Returns the number of arguments left that weren't recognized
1870 * (which are also moved to the head of the argument list)
1871 */
1872int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
1873{
1874        int i, flags, left, seen_dashdash, read_from_stdin, got_rev_arg = 0, revarg_opt;
1875        struct cmdline_pathspec prune_data;
1876        const char *submodule = NULL;
1877
1878        memset(&prune_data, 0, sizeof(prune_data));
1879        if (opt)
1880                submodule = opt->submodule;
1881
1882        /* First, search for "--" */
1883        if (opt && opt->assume_dashdash) {
1884                seen_dashdash = 1;
1885        } else {
1886                seen_dashdash = 0;
1887                for (i = 1; i < argc; i++) {
1888                        const char *arg = argv[i];
1889                        if (strcmp(arg, "--"))
1890                                continue;
1891                        argv[i] = NULL;
1892                        argc = i;
1893                        if (argv[i + 1])
1894                                append_prune_data(&prune_data, argv + i + 1);
1895                        seen_dashdash = 1;
1896                        break;
1897                }
1898        }
1899
1900        /* Second, deal with arguments and options */
1901        flags = 0;
1902        revarg_opt = opt ? opt->revarg_opt : 0;
1903        if (seen_dashdash)
1904                revarg_opt |= REVARG_CANNOT_BE_FILENAME;
1905        read_from_stdin = 0;
1906        for (left = i = 1; i < argc; i++) {
1907                const char *arg = argv[i];
1908                if (*arg == '-') {
1909                        int opts;
1910
1911                        opts = handle_revision_pseudo_opt(submodule,
1912                                                revs, argc - i, argv + i,
1913                                                &flags);
1914                        if (opts > 0) {
1915                                i += opts - 1;
1916                                continue;
1917                        }
1918
1919                        if (!strcmp(arg, "--stdin")) {
1920                                if (revs->disable_stdin) {
1921                                        argv[left++] = arg;
1922                                        continue;
1923                                }
1924                                if (read_from_stdin++)
1925                                        die("--stdin given twice?");
1926                                read_revisions_from_stdin(revs, &prune_data);
1927                                continue;
1928                        }
1929
1930                        opts = handle_revision_opt(revs, argc - i, argv + i, &left, argv);
1931                        if (opts > 0) {
1932                                i += opts - 1;
1933                                continue;
1934                        }
1935                        if (opts < 0)
1936                                exit(128);
1937                        continue;
1938                }
1939
1940
1941                if (handle_revision_arg(arg, revs, flags, revarg_opt)) {
1942                        int j;
1943                        if (seen_dashdash || *arg == '^')
1944                                die("bad revision '%s'", arg);
1945
1946                        /* If we didn't have a "--":
1947                         * (1) all filenames must exist;
1948                         * (2) all rev-args must not be interpretable
1949                         *     as a valid filename.
1950                         * but the latter we have checked in the main loop.
1951                         */
1952                        for (j = i; j < argc; j++)
1953                                verify_filename(revs->prefix, argv[j], j == i);
1954
1955                        append_prune_data(&prune_data, argv + i);
1956                        break;
1957                }
1958                else
1959                        got_rev_arg = 1;
1960        }
1961
1962        if (prune_data.nr) {
1963                /*
1964                 * If we need to introduce the magic "a lone ':' means no
1965                 * pathspec whatsoever", here is the place to do so.
1966                 *
1967                 * if (prune_data.nr == 1 && !strcmp(prune_data[0], ":")) {
1968                 *      prune_data.nr = 0;
1969                 *      prune_data.alloc = 0;
1970                 *      free(prune_data.path);
1971                 *      prune_data.path = NULL;
1972                 * } else {
1973                 *      terminate prune_data.alloc with NULL and
1974                 *      call init_pathspec() to set revs->prune_data here.
1975                 * }
1976                 */
1977                ALLOC_GROW(prune_data.path, prune_data.nr+1, prune_data.alloc);
1978                prune_data.path[prune_data.nr++] = NULL;
1979                init_pathspec(&revs->prune_data,
1980                              get_pathspec(revs->prefix, prune_data.path));
1981        }
1982
1983        if (revs->def == NULL)
1984                revs->def = opt ? opt->def : NULL;
1985        if (opt && opt->tweak)
1986                opt->tweak(revs, opt);
1987        if (revs->show_merge)
1988                prepare_show_merge(revs);
1989        if (revs->def && !revs->pending.nr && !got_rev_arg) {
1990                unsigned char sha1[20];
1991                struct object *object;
1992                struct object_context oc;
1993                if (get_sha1_with_context(revs->def, 0, sha1, &oc))
1994                        die("bad default revision '%s'", revs->def);
1995                object = get_reference(revs, revs->def, sha1, 0);
1996                add_pending_object_with_mode(revs, object, revs->def, oc.mode);
1997        }
1998
1999        /* Did the user ask for any diff output? Run the diff! */
2000        if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
2001                revs->diff = 1;
2002
2003        /* Pickaxe, diff-filter and rename following need diffs */
2004        if (revs->diffopt.pickaxe ||
2005            revs->diffopt.filter ||
2006            DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
2007                revs->diff = 1;
2008
2009        if (revs->topo_order)
2010                revs->limited = 1;
2011
2012        if (revs->prune_data.nr) {
2013                diff_tree_setup_paths(revs->prune_data.raw, &revs->pruning);
2014                /* Can't prune commits with rename following: the paths change.. */
2015                if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
2016                        revs->prune = 1;
2017                if (!revs->full_diff)
2018                        diff_tree_setup_paths(revs->prune_data.raw, &revs->diffopt);
2019        }
2020        if (revs->combine_merges)
2021                revs->ignore_merges = 0;
2022        revs->diffopt.abbrev = revs->abbrev;
2023        diff_setup_done(&revs->diffopt);
2024
2025        grep_commit_pattern_type(GREP_PATTERN_TYPE_UNSPECIFIED,
2026                                 &revs->grep_filter);
2027        compile_grep_patterns(&revs->grep_filter);
2028
2029        if (revs->reverse && revs->reflog_info)
2030                die("cannot combine --reverse with --walk-reflogs");
2031        if (revs->rewrite_parents && revs->children.name)
2032                die("cannot combine --parents and --children");
2033
2034        /*
2035         * Limitations on the graph functionality
2036         */
2037        if (revs->reverse && revs->graph)
2038                die("cannot combine --reverse with --graph");
2039
2040        if (revs->reflog_info && revs->graph)
2041                die("cannot combine --walk-reflogs with --graph");
2042        if (!revs->reflog_info && revs->grep_filter.use_reflog_filter)
2043                die("cannot use --grep-reflog without --walk-reflogs");
2044
2045        return left;
2046}
2047
2048static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
2049{
2050        struct commit_list *l = xcalloc(1, sizeof(*l));
2051
2052        l->item = child;
2053        l->next = add_decoration(&revs->children, &parent->object, l);
2054}
2055
2056static int remove_duplicate_parents(struct rev_info *revs, struct commit *commit)
2057{
2058        struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2059        struct commit_list **pp, *p;
2060        int surviving_parents;
2061
2062        /* Examine existing parents while marking ones we have seen... */
2063        pp = &commit->parents;
2064        surviving_parents = 0;
2065        while ((p = *pp) != NULL) {
2066                struct commit *parent = p->item;
2067                if (parent->object.flags & TMP_MARK) {
2068                        *pp = p->next;
2069                        if (ts)
2070                                compact_treesame(revs, commit, surviving_parents);
2071                        continue;
2072                }
2073                parent->object.flags |= TMP_MARK;
2074                surviving_parents++;
2075                pp = &p->next;
2076        }
2077        /* clear the temporary mark */
2078        for (p = commit->parents; p; p = p->next) {
2079                p->item->object.flags &= ~TMP_MARK;
2080        }
2081        /* no update_treesame() - removing duplicates can't affect TREESAME */
2082        return surviving_parents;
2083}
2084
2085struct merge_simplify_state {
2086        struct commit *simplified;
2087};
2088
2089static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
2090{
2091        struct merge_simplify_state *st;
2092
2093        st = lookup_decoration(&revs->merge_simplification, &commit->object);
2094        if (!st) {
2095                st = xcalloc(1, sizeof(*st));
2096                add_decoration(&revs->merge_simplification, &commit->object, st);
2097        }
2098        return st;
2099}
2100
2101static int mark_redundant_parents(struct rev_info *revs, struct commit *commit)
2102{
2103        struct commit_list *h = reduce_heads(commit->parents);
2104        int i = 0, marked = 0;
2105        struct commit_list *po, *pn;
2106
2107        /* Want these for sanity-checking only */
2108        int orig_cnt = commit_list_count(commit->parents);
2109        int cnt = commit_list_count(h);
2110
2111        /*
2112         * Not ready to remove items yet, just mark them for now, based
2113         * on the output of reduce_heads(). reduce_heads outputs the reduced
2114         * set in its original order, so this isn't too hard.
2115         */
2116        po = commit->parents;
2117        pn = h;
2118        while (po) {
2119                if (pn && po->item == pn->item) {
2120                        pn = pn->next;
2121                        i++;
2122                } else {
2123                        po->item->object.flags |= TMP_MARK;
2124                        marked++;
2125                }
2126                po=po->next;
2127        }
2128
2129        if (i != cnt || cnt+marked != orig_cnt)
2130                die("mark_redundant_parents %d %d %d %d", orig_cnt, cnt, i, marked);
2131
2132        free_commit_list(h);
2133
2134        return marked;
2135}
2136
2137static int mark_treesame_root_parents(struct rev_info *revs, struct commit *commit)
2138{
2139        struct commit_list *p;
2140        int marked = 0;
2141
2142        for (p = commit->parents; p; p = p->next) {
2143                struct commit *parent = p->item;
2144                if (!parent->parents && (parent->object.flags & TREESAME)) {
2145                        parent->object.flags |= TMP_MARK;
2146                        marked++;
2147                }
2148        }
2149
2150        return marked;
2151}
2152
2153/*
2154 * Awkward naming - this means one parent we are TREESAME to.
2155 * cf mark_treesame_root_parents: root parents that are TREESAME (to an
2156 * empty tree). Better name suggestions?
2157 */
2158static int leave_one_treesame_to_parent(struct rev_info *revs, struct commit *commit)
2159{
2160        struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2161        struct commit *unmarked = NULL, *marked = NULL;
2162        struct commit_list *p;
2163        unsigned n;
2164
2165        for (p = commit->parents, n = 0; p; p = p->next, n++) {
2166                if (ts->treesame[n]) {
2167                        if (p->item->object.flags & TMP_MARK) {
2168                                if (!marked)
2169                                        marked = p->item;
2170                        } else {
2171                                if (!unmarked) {
2172                                        unmarked = p->item;
2173                                        break;
2174                                }
2175                        }
2176                }
2177        }
2178
2179        /*
2180         * If we are TREESAME to a marked-for-deletion parent, but not to any
2181         * unmarked parents, unmark the first TREESAME parent. This is the
2182         * parent that the default simplify_history==1 scan would have followed,
2183         * and it doesn't make sense to omit that path when asking for a
2184         * simplified full history. Retaining it improves the chances of
2185         * understanding odd missed merges that took an old version of a file.
2186         *
2187         * Example:
2188         *
2189         *   I--------*X       A modified the file, but mainline merge X used
2190         *    \       /        "-s ours", so took the version from I. X is
2191         *     `-*A--'         TREESAME to I and !TREESAME to A.
2192         *
2193         * Default log from X would produce "I". Without this check,
2194         * --full-history --simplify-merges would produce "I-A-X", showing
2195         * the merge commit X and that it changed A, but not making clear that
2196         * it had just taken the I version. With this check, the topology above
2197         * is retained.
2198         *
2199         * Note that it is possible that the simplification chooses a different
2200         * TREESAME parent from the default, in which case this test doesn't
2201         * activate, and we _do_ drop the default parent. Example:
2202         *
2203         *   I------X         A modified the file, but it was reverted in B,
2204         *    \    /          meaning mainline merge X is TREESAME to both
2205         *    *A-*B           parents.
2206         *
2207         * Default log would produce "I" by following the first parent;
2208         * --full-history --simplify-merges will produce "I-A-B". But this is a
2209         * reasonable result - it presents a logical full history leading from
2210         * I to X, and X is not an important merge.
2211         */
2212        if (!unmarked && marked) {
2213                marked->object.flags &= ~TMP_MARK;
2214                return 1;
2215        }
2216
2217        return 0;
2218}
2219
2220static int remove_marked_parents(struct rev_info *revs, struct commit *commit)
2221{
2222        struct commit_list **pp, *p;
2223        int nth_parent, removed = 0;
2224
2225        pp = &commit->parents;
2226        nth_parent = 0;
2227        while ((p = *pp) != NULL) {
2228                struct commit *parent = p->item;
2229                if (parent->object.flags & TMP_MARK) {
2230                        parent->object.flags &= ~TMP_MARK;
2231                        *pp = p->next;
2232                        free(p);
2233                        removed++;
2234                        compact_treesame(revs, commit, nth_parent);
2235                        continue;
2236                }
2237                pp = &p->next;
2238                nth_parent++;
2239        }
2240
2241        /* Removing parents can only increase TREESAMEness */
2242        if (removed && !(commit->object.flags & TREESAME))
2243                update_treesame(revs, commit);
2244
2245        return nth_parent;
2246}
2247
2248static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
2249{
2250        struct commit_list *p;
2251        struct merge_simplify_state *st, *pst;
2252        int cnt;
2253
2254        st = locate_simplify_state(revs, commit);
2255
2256        /*
2257         * Have we handled this one?
2258         */
2259        if (st->simplified)
2260                return tail;
2261
2262        /*
2263         * An UNINTERESTING commit simplifies to itself, so does a
2264         * root commit.  We do not rewrite parents of such commit
2265         * anyway.
2266         */
2267        if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
2268                st->simplified = commit;
2269                return tail;
2270        }
2271
2272        /*
2273         * Do we know what commit all of our parents that matter
2274         * should be rewritten to?  Otherwise we are not ready to
2275         * rewrite this one yet.
2276         */
2277        for (cnt = 0, p = commit->parents; p; p = p->next) {
2278                pst = locate_simplify_state(revs, p->item);
2279                if (!pst->simplified) {
2280                        tail = &commit_list_insert(p->item, tail)->next;
2281                        cnt++;
2282                }
2283                if (revs->first_parent_only)
2284                        break;
2285        }
2286        if (cnt) {
2287                tail = &commit_list_insert(commit, tail)->next;
2288                return tail;
2289        }
2290
2291        /*
2292         * Rewrite our list of parents. Note that this cannot
2293         * affect our TREESAME flags in any way - a commit is
2294         * always TREESAME to its simplification.
2295         */
2296        for (p = commit->parents; p; p = p->next) {
2297                pst = locate_simplify_state(revs, p->item);
2298                p->item = pst->simplified;
2299                if (revs->first_parent_only)
2300                        break;
2301        }
2302
2303        if (revs->first_parent_only)
2304                cnt = 1;
2305        else
2306                cnt = remove_duplicate_parents(revs, commit);
2307
2308        /*
2309         * It is possible that we are a merge and one side branch
2310         * does not have any commit that touches the given paths;
2311         * in such a case, the immediate parent from that branch
2312         * will be rewritten to be the merge base.
2313         *
2314         *      o----X          X: the commit we are looking at;
2315         *     /    /           o: a commit that touches the paths;
2316         * ---o----'
2317         *
2318         * Further, a merge of an independent branch that doesn't
2319         * touch the path will reduce to a treesame root parent:
2320         *
2321         *  ----o----X          X: the commit we are looking at;
2322         *          /           o: a commit that touches the paths;
2323         *         r            r: a root commit not touching the paths
2324         *
2325         * Detect and simplify both cases.
2326         */
2327        if (1 < cnt) {
2328                int marked = mark_redundant_parents(revs, commit);
2329                marked += mark_treesame_root_parents(revs, commit);
2330                if (marked)
2331                        marked -= leave_one_treesame_to_parent(revs, commit);
2332                if (marked)
2333                        cnt = remove_marked_parents(revs, commit);
2334        }
2335
2336        /*
2337         * A commit simplifies to itself if it is a root, if it is
2338         * UNINTERESTING, if it touches the given paths, or if it is a
2339         * merge and its parents simplify to more than one commit
2340         * (the first two cases are already handled at the beginning of
2341         * this function).
2342         *
2343         * Otherwise, it simplifies to what its sole parent simplifies to.
2344         */
2345        if (!cnt ||
2346            (commit->object.flags & UNINTERESTING) ||
2347            !(commit->object.flags & TREESAME) ||
2348            (1 < cnt))
2349                st->simplified = commit;
2350        else {
2351                pst = locate_simplify_state(revs, commit->parents->item);
2352                st->simplified = pst->simplified;
2353        }
2354        return tail;
2355}
2356
2357static void simplify_merges(struct rev_info *revs)
2358{
2359        struct commit_list *list, *next;
2360        struct commit_list *yet_to_do, **tail;
2361        struct commit *commit;
2362
2363        if (!revs->prune)
2364                return;
2365
2366        /* feed the list reversed */
2367        yet_to_do = NULL;
2368        for (list = revs->commits; list; list = next) {
2369                commit = list->item;
2370                next = list->next;
2371                /*
2372                 * Do not free(list) here yet; the original list
2373                 * is used later in this function.
2374                 */
2375                commit_list_insert(commit, &yet_to_do);
2376        }
2377        while (yet_to_do) {
2378                list = yet_to_do;
2379                yet_to_do = NULL;
2380                tail = &yet_to_do;
2381                while (list) {
2382                        commit = list->item;
2383                        next = list->next;
2384                        free(list);
2385                        list = next;
2386                        tail = simplify_one(revs, commit, tail);
2387                }
2388        }
2389
2390        /* clean up the result, removing the simplified ones */
2391        list = revs->commits;
2392        revs->commits = NULL;
2393        tail = &revs->commits;
2394        while (list) {
2395                struct merge_simplify_state *st;
2396
2397                commit = list->item;
2398                next = list->next;
2399                free(list);
2400                list = next;
2401                st = locate_simplify_state(revs, commit);
2402                if (st->simplified == commit)
2403                        tail = &commit_list_insert(commit, tail)->next;
2404        }
2405}
2406
2407static void set_children(struct rev_info *revs)
2408{
2409        struct commit_list *l;
2410        for (l = revs->commits; l; l = l->next) {
2411                struct commit *commit = l->item;
2412                struct commit_list *p;
2413
2414                for (p = commit->parents; p; p = p->next)
2415                        add_child(revs, p->item, commit);
2416        }
2417}
2418
2419void reset_revision_walk(void)
2420{
2421        clear_object_flags(SEEN | ADDED | SHOWN);
2422}
2423
2424int prepare_revision_walk(struct rev_info *revs)
2425{
2426        int nr = revs->pending.nr;
2427        struct object_array_entry *e, *list;
2428        struct commit_list **next = &revs->commits;
2429
2430        e = list = revs->pending.objects;
2431        revs->pending.nr = 0;
2432        revs->pending.alloc = 0;
2433        revs->pending.objects = NULL;
2434        while (--nr >= 0) {
2435                struct commit *commit = handle_commit(revs, e->item, e->name);
2436                if (commit) {
2437                        if (!(commit->object.flags & SEEN)) {
2438                                commit->object.flags |= SEEN;
2439                                next = commit_list_append(commit, next);
2440                        }
2441                }
2442                e++;
2443        }
2444        if (!revs->leak_pending)
2445                free(list);
2446
2447        /* Signal whether we need per-parent treesame decoration */
2448        if (revs->simplify_merges)
2449                revs->treesame.name = "treesame";
2450
2451        if (revs->no_walk != REVISION_WALK_NO_WALK_UNSORTED)
2452                commit_list_sort_by_date(&revs->commits);
2453        if (revs->no_walk)
2454                return 0;
2455        if (revs->limited)
2456                if (limit_list(revs) < 0)
2457                        return -1;
2458        if (revs->topo_order)
2459                sort_in_topological_order(&revs->commits, revs->lifo);
2460        if (revs->simplify_merges)
2461                simplify_merges(revs);
2462        if (revs->children.name)
2463                set_children(revs);
2464        return 0;
2465}
2466
2467enum rewrite_result {
2468        rewrite_one_ok,
2469        rewrite_one_noparents,
2470        rewrite_one_error
2471};
2472
2473static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
2474{
2475        struct commit_list *cache = NULL;
2476
2477        for (;;) {
2478                struct commit *p = *pp;
2479                if (!revs->limited)
2480                        if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0)
2481                                return rewrite_one_error;
2482                if (p->parents && p->parents->next)
2483                        return rewrite_one_ok;
2484                if (p->object.flags & UNINTERESTING)
2485                        return rewrite_one_ok;
2486                if (!(p->object.flags & TREESAME))
2487                        return rewrite_one_ok;
2488                if (!p->parents)
2489                        return rewrite_one_noparents;
2490                *pp = p->parents->item;
2491        }
2492}
2493
2494static int rewrite_parents(struct rev_info *revs, struct commit *commit)
2495{
2496        struct commit_list **pp = &commit->parents;
2497        while (*pp) {
2498                struct commit_list *parent = *pp;
2499                switch (rewrite_one(revs, &parent->item)) {
2500                case rewrite_one_ok:
2501                        break;
2502                case rewrite_one_noparents:
2503                        *pp = parent->next;
2504                        continue;
2505                case rewrite_one_error:
2506                        return -1;
2507                }
2508                pp = &parent->next;
2509        }
2510        remove_duplicate_parents(revs, commit);
2511        return 0;
2512}
2513
2514static int commit_rewrite_person(struct strbuf *buf, const char *what, struct string_list *mailmap)
2515{
2516        char *person, *endp;
2517        size_t len, namelen, maillen;
2518        const char *name;
2519        const char *mail;
2520        struct ident_split ident;
2521
2522        person = strstr(buf->buf, what);
2523        if (!person)
2524                return 0;
2525
2526        person += strlen(what);
2527        endp = strchr(person, '\n');
2528        if (!endp)
2529                return 0;
2530
2531        len = endp - person;
2532
2533        if (split_ident_line(&ident, person, len))
2534                return 0;
2535
2536        mail = ident.mail_begin;
2537        maillen = ident.mail_end - ident.mail_begin;
2538        name = ident.name_begin;
2539        namelen = ident.name_end - ident.name_begin;
2540
2541        if (map_user(mailmap, &mail, &maillen, &name, &namelen)) {
2542                struct strbuf namemail = STRBUF_INIT;
2543
2544                strbuf_addf(&namemail, "%.*s <%.*s>",
2545                            (int)namelen, name, (int)maillen, mail);
2546
2547                strbuf_splice(buf, ident.name_begin - buf->buf,
2548                              ident.mail_end - ident.name_begin + 1,
2549                              namemail.buf, namemail.len);
2550
2551                strbuf_release(&namemail);
2552
2553                return 1;
2554        }
2555
2556        return 0;
2557}
2558
2559static int commit_match(struct commit *commit, struct rev_info *opt)
2560{
2561        int retval;
2562        const char *encoding;
2563        char *message;
2564        struct strbuf buf = STRBUF_INIT;
2565
2566        if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
2567                return 1;
2568
2569        /* Prepend "fake" headers as needed */
2570        if (opt->grep_filter.use_reflog_filter) {
2571                strbuf_addstr(&buf, "reflog ");
2572                get_reflog_message(&buf, opt->reflog_info);
2573                strbuf_addch(&buf, '\n');
2574        }
2575
2576        /*
2577         * We grep in the user's output encoding, under the assumption that it
2578         * is the encoding they are most likely to write their grep pattern
2579         * for. In addition, it means we will match the "notes" encoding below,
2580         * so we will not end up with a buffer that has two different encodings
2581         * in it.
2582         */
2583        encoding = get_log_output_encoding();
2584        message = logmsg_reencode(commit, NULL, encoding);
2585
2586        /* Copy the commit to temporary if we are using "fake" headers */
2587        if (buf.len)
2588                strbuf_addstr(&buf, message);
2589
2590        if (opt->grep_filter.header_list && opt->mailmap) {
2591                if (!buf.len)
2592                        strbuf_addstr(&buf, message);
2593
2594                commit_rewrite_person(&buf, "\nauthor ", opt->mailmap);
2595                commit_rewrite_person(&buf, "\ncommitter ", opt->mailmap);
2596        }
2597
2598        /* Append "fake" message parts as needed */
2599        if (opt->show_notes) {
2600                if (!buf.len)
2601                        strbuf_addstr(&buf, message);
2602                format_display_notes(commit->object.sha1, &buf, encoding, 1);
2603        }
2604
2605        /* Find either in the original commit message, or in the temporary */
2606        if (buf.len)
2607                retval = grep_buffer(&opt->grep_filter, buf.buf, buf.len);
2608        else
2609                retval = grep_buffer(&opt->grep_filter,
2610                                     message, strlen(message));
2611        strbuf_release(&buf);
2612        logmsg_free(message, commit);
2613        return retval;
2614}
2615
2616static inline int want_ancestry(struct rev_info *revs)
2617{
2618        return (revs->rewrite_parents || revs->children.name);
2619}
2620
2621enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
2622{
2623        if (commit->object.flags & SHOWN)
2624                return commit_ignore;
2625        if (revs->unpacked && has_sha1_pack(commit->object.sha1))
2626                return commit_ignore;
2627        if (revs->show_all)
2628                return commit_show;
2629        if (commit->object.flags & UNINTERESTING)
2630                return commit_ignore;
2631        if (revs->min_age != -1 && (commit->date > revs->min_age))
2632                return commit_ignore;
2633        if (revs->min_parents || (revs->max_parents >= 0)) {
2634                int n = 0;
2635                struct commit_list *p;
2636                for (p = commit->parents; p; p = p->next)
2637                        n++;
2638                if ((n < revs->min_parents) ||
2639                    ((revs->max_parents >= 0) && (n > revs->max_parents)))
2640                        return commit_ignore;
2641        }
2642        if (!commit_match(commit, revs))
2643                return commit_ignore;
2644        if (revs->prune && revs->dense) {
2645                /* Commit without changes? */
2646                if (commit->object.flags & TREESAME) {
2647                        /* drop merges unless we want parenthood */
2648                        if (!want_ancestry(revs))
2649                                return commit_ignore;
2650                        /* non-merge - always ignore it */
2651                        if (!commit->parents || !commit->parents->next)
2652                                return commit_ignore;
2653                }
2654        }
2655        return commit_show;
2656}
2657
2658enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
2659{
2660        enum commit_action action = get_commit_action(revs, commit);
2661
2662        if (action == commit_show &&
2663            !revs->show_all &&
2664            revs->prune && revs->dense && want_ancestry(revs)) {
2665                if (rewrite_parents(revs, commit) < 0)
2666                        return commit_error;
2667        }
2668        return action;
2669}
2670
2671static struct commit *get_revision_1(struct rev_info *revs)
2672{
2673        if (!revs->commits)
2674                return NULL;
2675
2676        do {
2677                struct commit_list *entry = revs->commits;
2678                struct commit *commit = entry->item;
2679
2680                revs->commits = entry->next;
2681                free(entry);
2682
2683                if (revs->reflog_info) {
2684                        fake_reflog_parent(revs->reflog_info, commit);
2685                        commit->object.flags &= ~(ADDED | SEEN | SHOWN);
2686                }
2687
2688                /*
2689                 * If we haven't done the list limiting, we need to look at
2690                 * the parents here. We also need to do the date-based limiting
2691                 * that we'd otherwise have done in limit_list().
2692                 */
2693                if (!revs->limited) {
2694                        if (revs->max_age != -1 &&
2695                            (commit->date < revs->max_age))
2696                                continue;
2697                        if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0)
2698                                die("Failed to traverse parents of commit %s",
2699                                    sha1_to_hex(commit->object.sha1));
2700                }
2701
2702                switch (simplify_commit(revs, commit)) {
2703                case commit_ignore:
2704                        continue;
2705                case commit_error:
2706                        die("Failed to simplify parents of commit %s",
2707                            sha1_to_hex(commit->object.sha1));
2708                default:
2709                        return commit;
2710                }
2711        } while (revs->commits);
2712        return NULL;
2713}
2714
2715static void gc_boundary(struct object_array *array)
2716{
2717        unsigned nr = array->nr;
2718        unsigned alloc = array->alloc;
2719        struct object_array_entry *objects = array->objects;
2720
2721        if (alloc <= nr) {
2722                unsigned i, j;
2723                for (i = j = 0; i < nr; i++) {
2724                        if (objects[i].item->flags & SHOWN)
2725                                continue;
2726                        if (i != j)
2727                                objects[j] = objects[i];
2728                        j++;
2729                }
2730                for (i = j; i < nr; i++)
2731                        objects[i].item = NULL;
2732                array->nr = j;
2733        }
2734}
2735
2736static void create_boundary_commit_list(struct rev_info *revs)
2737{
2738        unsigned i;
2739        struct commit *c;
2740        struct object_array *array = &revs->boundary_commits;
2741        struct object_array_entry *objects = array->objects;
2742
2743        /*
2744         * If revs->commits is non-NULL at this point, an error occurred in
2745         * get_revision_1().  Ignore the error and continue printing the
2746         * boundary commits anyway.  (This is what the code has always
2747         * done.)
2748         */
2749        if (revs->commits) {
2750                free_commit_list(revs->commits);
2751                revs->commits = NULL;
2752        }
2753
2754        /*
2755         * Put all of the actual boundary commits from revs->boundary_commits
2756         * into revs->commits
2757         */
2758        for (i = 0; i < array->nr; i++) {
2759                c = (struct commit *)(objects[i].item);
2760                if (!c)
2761                        continue;
2762                if (!(c->object.flags & CHILD_SHOWN))
2763                        continue;
2764                if (c->object.flags & (SHOWN | BOUNDARY))
2765                        continue;
2766                c->object.flags |= BOUNDARY;
2767                commit_list_insert(c, &revs->commits);
2768        }
2769
2770        /*
2771         * If revs->topo_order is set, sort the boundary commits
2772         * in topological order
2773         */
2774        sort_in_topological_order(&revs->commits, revs->lifo);
2775}
2776
2777static struct commit *get_revision_internal(struct rev_info *revs)
2778{
2779        struct commit *c = NULL;
2780        struct commit_list *l;
2781
2782        if (revs->boundary == 2) {
2783                /*
2784                 * All of the normal commits have already been returned,
2785                 * and we are now returning boundary commits.
2786                 * create_boundary_commit_list() has populated
2787                 * revs->commits with the remaining commits to return.
2788                 */
2789                c = pop_commit(&revs->commits);
2790                if (c)
2791                        c->object.flags |= SHOWN;
2792                return c;
2793        }
2794
2795        /*
2796         * If our max_count counter has reached zero, then we are done. We
2797         * don't simply return NULL because we still might need to show
2798         * boundary commits. But we want to avoid calling get_revision_1, which
2799         * might do a considerable amount of work finding the next commit only
2800         * for us to throw it away.
2801         *
2802         * If it is non-zero, then either we don't have a max_count at all
2803         * (-1), or it is still counting, in which case we decrement.
2804         */
2805        if (revs->max_count) {
2806                c = get_revision_1(revs);
2807                if (c) {
2808                        while (0 < revs->skip_count) {
2809                                revs->skip_count--;
2810                                c = get_revision_1(revs);
2811                                if (!c)
2812                                        break;
2813                        }
2814                }
2815
2816                if (revs->max_count > 0)
2817                        revs->max_count--;
2818        }
2819
2820        if (c)
2821                c->object.flags |= SHOWN;
2822
2823        if (!revs->boundary) {
2824                return c;
2825        }
2826
2827        if (!c) {
2828                /*
2829                 * get_revision_1() runs out the commits, and
2830                 * we are done computing the boundaries.
2831                 * switch to boundary commits output mode.
2832                 */
2833                revs->boundary = 2;
2834
2835                /*
2836                 * Update revs->commits to contain the list of
2837                 * boundary commits.
2838                 */
2839                create_boundary_commit_list(revs);
2840
2841                return get_revision_internal(revs);
2842        }
2843
2844        /*
2845         * boundary commits are the commits that are parents of the
2846         * ones we got from get_revision_1() but they themselves are
2847         * not returned from get_revision_1().  Before returning
2848         * 'c', we need to mark its parents that they could be boundaries.
2849         */
2850
2851        for (l = c->parents; l; l = l->next) {
2852                struct object *p;
2853                p = &(l->item->object);
2854                if (p->flags & (CHILD_SHOWN | SHOWN))
2855                        continue;
2856                p->flags |= CHILD_SHOWN;
2857                gc_boundary(&revs->boundary_commits);
2858                add_object_array(p, NULL, &revs->boundary_commits);
2859        }
2860
2861        return c;
2862}
2863
2864struct commit *get_revision(struct rev_info *revs)
2865{
2866        struct commit *c;
2867        struct commit_list *reversed;
2868
2869        if (revs->reverse) {
2870                reversed = NULL;
2871                while ((c = get_revision_internal(revs))) {
2872                        commit_list_insert(c, &reversed);
2873                }
2874                revs->commits = reversed;
2875                revs->reverse = 0;
2876                revs->reverse_output_stage = 1;
2877        }
2878
2879        if (revs->reverse_output_stage)
2880                return pop_commit(&revs->commits);
2881
2882        c = get_revision_internal(revs);
2883        if (c && revs->graph)
2884                graph_update(revs->graph, c);
2885        return c;
2886}
2887
2888char *get_revision_mark(const struct rev_info *revs, const struct commit *commit)
2889{
2890        if (commit->object.flags & BOUNDARY)
2891                return "-";
2892        else if (commit->object.flags & UNINTERESTING)
2893                return "^";
2894        else if (commit->object.flags & PATCHSAME)
2895                return "=";
2896        else if (!revs || revs->left_right) {
2897                if (commit->object.flags & SYMMETRIC_LEFT)
2898                        return "<";
2899                else
2900                        return ">";
2901        } else if (revs->graph)
2902                return "*";
2903        else if (revs->cherry_mark)
2904                return "+";
2905        return "";
2906}
2907
2908void put_revision_mark(const struct rev_info *revs, const struct commit *commit)
2909{
2910        char *mark = get_revision_mark(revs, commit);
2911        if (!strlen(mark))
2912                return;
2913        fputs(mark, stdout);
2914        putchar(' ');
2915}