revision.con commit git_connect: remove artificial limit of a remote command (d98d109)
   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 "line-log.h"
  17#include "mailmap.h"
  18#include "commit-slab.h"
  19
  20volatile show_early_output_fn_t show_early_output;
  21
  22char *path_name(const struct name_path *path, const char *name)
  23{
  24        const struct name_path *p;
  25        char *n, *m;
  26        int nlen = strlen(name);
  27        int len = nlen + 1;
  28
  29        for (p = path; p; p = p->up) {
  30                if (p->elem_len)
  31                        len += p->elem_len + 1;
  32        }
  33        n = xmalloc(len);
  34        m = n + len - (nlen + 1);
  35        strcpy(m, name);
  36        for (p = path; p; p = p->up) {
  37                if (p->elem_len) {
  38                        m -= p->elem_len + 1;
  39                        memcpy(m, p->elem, p->elem_len);
  40                        m[p->elem_len] = '/';
  41                }
  42        }
  43        return n;
  44}
  45
  46static int show_path_component_truncated(FILE *out, const char *name, int len)
  47{
  48        int cnt;
  49        for (cnt = 0; cnt < len; cnt++) {
  50                int ch = name[cnt];
  51                if (!ch || ch == '\n')
  52                        return -1;
  53                fputc(ch, out);
  54        }
  55        return len;
  56}
  57
  58static int show_path_truncated(FILE *out, const struct name_path *path)
  59{
  60        int emitted, ours;
  61
  62        if (!path)
  63                return 0;
  64        emitted = show_path_truncated(out, path->up);
  65        if (emitted < 0)
  66                return emitted;
  67        if (emitted)
  68                fputc('/', out);
  69        ours = show_path_component_truncated(out, path->elem, path->elem_len);
  70        if (ours < 0)
  71                return ours;
  72        return ours || emitted;
  73}
  74
  75void show_object_with_name(FILE *out, struct object *obj,
  76                           const struct name_path *path, const char *component)
  77{
  78        struct name_path leaf;
  79        leaf.up = (struct name_path *)path;
  80        leaf.elem = component;
  81        leaf.elem_len = strlen(component);
  82
  83        fprintf(out, "%s ", sha1_to_hex(obj->sha1));
  84        show_path_truncated(out, &leaf);
  85        fputc('\n', out);
  86}
  87
  88void add_object(struct object *obj,
  89                struct object_array *p,
  90                struct name_path *path,
  91                const char *name)
  92{
  93        char *pn = path_name(path, name);
  94        add_object_array(obj, pn, p);
  95        free(pn);
  96}
  97
  98static void mark_blob_uninteresting(struct blob *blob)
  99{
 100        if (!blob)
 101                return;
 102        if (blob->object.flags & UNINTERESTING)
 103                return;
 104        blob->object.flags |= UNINTERESTING;
 105}
 106
 107void mark_tree_uninteresting(struct tree *tree)
 108{
 109        struct tree_desc desc;
 110        struct name_entry entry;
 111        struct object *obj = &tree->object;
 112
 113        if (!tree)
 114                return;
 115        if (obj->flags & UNINTERESTING)
 116                return;
 117        obj->flags |= UNINTERESTING;
 118        if (!has_sha1_file(obj->sha1))
 119                return;
 120        if (parse_tree(tree) < 0)
 121                die("bad tree %s", sha1_to_hex(obj->sha1));
 122
 123        init_tree_desc(&desc, tree->buffer, tree->size);
 124        while (tree_entry(&desc, &entry)) {
 125                switch (object_type(entry.mode)) {
 126                case OBJ_TREE:
 127                        mark_tree_uninteresting(lookup_tree(entry.sha1));
 128                        break;
 129                case OBJ_BLOB:
 130                        mark_blob_uninteresting(lookup_blob(entry.sha1));
 131                        break;
 132                default:
 133                        /* Subproject commit - not in this repository */
 134                        break;
 135                }
 136        }
 137
 138        /*
 139         * We don't care about the tree any more
 140         * after it has been marked uninteresting.
 141         */
 142        free_tree_buffer(tree);
 143}
 144
 145void mark_parents_uninteresting(struct commit *commit)
 146{
 147        struct commit_list *parents = NULL, *l;
 148
 149        for (l = commit->parents; l; l = l->next)
 150                commit_list_insert(l->item, &parents);
 151
 152        while (parents) {
 153                struct commit *commit = parents->item;
 154                l = parents;
 155                parents = parents->next;
 156                free(l);
 157
 158                while (commit) {
 159                        /*
 160                         * A missing commit is ok iff its parent is marked
 161                         * uninteresting.
 162                         *
 163                         * We just mark such a thing parsed, so that when
 164                         * it is popped next time around, we won't be trying
 165                         * to parse it and get an error.
 166                         */
 167                        if (!has_sha1_file(commit->object.sha1))
 168                                commit->object.parsed = 1;
 169
 170                        if (commit->object.flags & UNINTERESTING)
 171                                break;
 172
 173                        commit->object.flags |= UNINTERESTING;
 174
 175                        /*
 176                         * Normally we haven't parsed the parent
 177                         * yet, so we won't have a parent of a parent
 178                         * here. However, it may turn out that we've
 179                         * reached this commit some other way (where it
 180                         * wasn't uninteresting), in which case we need
 181                         * to mark its parents recursively too..
 182                         */
 183                        if (!commit->parents)
 184                                break;
 185
 186                        for (l = commit->parents->next; l; l = l->next)
 187                                commit_list_insert(l->item, &parents);
 188                        commit = commit->parents->item;
 189                }
 190        }
 191}
 192
 193static void add_pending_object_with_mode(struct rev_info *revs,
 194                                         struct object *obj,
 195                                         const char *name, unsigned mode)
 196{
 197        if (!obj)
 198                return;
 199        if (revs->no_walk && (obj->flags & UNINTERESTING))
 200                revs->no_walk = 0;
 201        if (revs->reflog_info && obj->type == OBJ_COMMIT) {
 202                struct strbuf buf = STRBUF_INIT;
 203                int len = interpret_branch_name(name, 0, &buf);
 204                int st;
 205
 206                if (0 < len && name[len] && buf.len)
 207                        strbuf_addstr(&buf, name + len);
 208                st = add_reflog_for_walk(revs->reflog_info,
 209                                         (struct commit *)obj,
 210                                         buf.buf[0] ? buf.buf: name);
 211                strbuf_release(&buf);
 212                if (st)
 213                        return;
 214        }
 215        add_object_array_with_mode(obj, name, &revs->pending, mode);
 216}
 217
 218void add_pending_object(struct rev_info *revs,
 219                        struct object *obj, const char *name)
 220{
 221        add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
 222}
 223
 224void add_head_to_pending(struct rev_info *revs)
 225{
 226        unsigned char sha1[20];
 227        struct object *obj;
 228        if (get_sha1("HEAD", sha1))
 229                return;
 230        obj = parse_object(sha1);
 231        if (!obj)
 232                return;
 233        add_pending_object(revs, obj, "HEAD");
 234}
 235
 236static struct object *get_reference(struct rev_info *revs, const char *name,
 237                                    const unsigned char *sha1,
 238                                    unsigned int flags)
 239{
 240        struct object *object;
 241
 242        object = parse_object(sha1);
 243        if (!object) {
 244                if (revs->ignore_missing)
 245                        return object;
 246                die("bad object %s", name);
 247        }
 248        object->flags |= flags;
 249        return object;
 250}
 251
 252void add_pending_sha1(struct rev_info *revs, const char *name,
 253                      const unsigned char *sha1, unsigned int flags)
 254{
 255        struct object *object = get_reference(revs, name, sha1, flags);
 256        add_pending_object(revs, object, name);
 257}
 258
 259static struct commit *handle_commit(struct rev_info *revs,
 260                                    struct object *object, const char *name)
 261{
 262        unsigned long flags = object->flags;
 263
 264        /*
 265         * Tag object? Look what it points to..
 266         */
 267        while (object->type == OBJ_TAG) {
 268                struct tag *tag = (struct tag *) object;
 269                if (revs->tag_objects && !(flags & UNINTERESTING))
 270                        add_pending_object(revs, object, tag->tag);
 271                if (!tag->tagged)
 272                        die("bad tag");
 273                object = parse_object(tag->tagged->sha1);
 274                if (!object) {
 275                        if (flags & UNINTERESTING)
 276                                return NULL;
 277                        die("bad object %s", sha1_to_hex(tag->tagged->sha1));
 278                }
 279        }
 280
 281        /*
 282         * Commit object? Just return it, we'll do all the complex
 283         * reachability crud.
 284         */
 285        if (object->type == OBJ_COMMIT) {
 286                struct commit *commit = (struct commit *)object;
 287                if (parse_commit(commit) < 0)
 288                        die("unable to parse commit %s", name);
 289                if (flags & UNINTERESTING) {
 290                        commit->object.flags |= UNINTERESTING;
 291                        mark_parents_uninteresting(commit);
 292                        revs->limited = 1;
 293                }
 294                if (revs->show_source && !commit->util)
 295                        commit->util = (void *) name;
 296                return commit;
 297        }
 298
 299        /*
 300         * Tree object? Either mark it uninteresting, or add it
 301         * to the list of objects to look at later..
 302         */
 303        if (object->type == OBJ_TREE) {
 304                struct tree *tree = (struct tree *)object;
 305                if (!revs->tree_objects)
 306                        return NULL;
 307                if (flags & UNINTERESTING) {
 308                        mark_tree_uninteresting(tree);
 309                        return NULL;
 310                }
 311                add_pending_object(revs, object, "");
 312                return NULL;
 313        }
 314
 315        /*
 316         * Blob object? You know the drill by now..
 317         */
 318        if (object->type == OBJ_BLOB) {
 319                struct blob *blob = (struct blob *)object;
 320                if (!revs->blob_objects)
 321                        return NULL;
 322                if (flags & UNINTERESTING) {
 323                        mark_blob_uninteresting(blob);
 324                        return NULL;
 325                }
 326                add_pending_object(revs, object, "");
 327                return NULL;
 328        }
 329        die("%s is unknown object", name);
 330}
 331
 332static int everybody_uninteresting(struct commit_list *orig)
 333{
 334        struct commit_list *list = orig;
 335        while (list) {
 336                struct commit *commit = list->item;
 337                list = list->next;
 338                if (commit->object.flags & UNINTERESTING)
 339                        continue;
 340                return 0;
 341        }
 342        return 1;
 343}
 344
 345/*
 346 * A definition of "relevant" commit that we can use to simplify limited graphs
 347 * by eliminating side branches.
 348 *
 349 * A "relevant" commit is one that is !UNINTERESTING (ie we are including it
 350 * in our list), or that is a specified BOTTOM commit. Then after computing
 351 * a limited list, during processing we can generally ignore boundary merges
 352 * coming from outside the graph, (ie from irrelevant parents), and treat
 353 * those merges as if they were single-parent. TREESAME is defined to consider
 354 * only relevant parents, if any. If we are TREESAME to our on-graph parents,
 355 * we don't care if we were !TREESAME to non-graph parents.
 356 *
 357 * Treating bottom commits as relevant ensures that a limited graph's
 358 * connection to the actual bottom commit is not viewed as a side branch, but
 359 * treated as part of the graph. For example:
 360 *
 361 *   ....Z...A---X---o---o---B
 362 *        .     /
 363 *         W---Y
 364 *
 365 * When computing "A..B", the A-X connection is at least as important as
 366 * Y-X, despite A being flagged UNINTERESTING.
 367 *
 368 * And when computing --ancestry-path "A..B", the A-X connection is more
 369 * important than Y-X, despite both A and Y being flagged UNINTERESTING.
 370 */
 371static inline int relevant_commit(struct commit *commit)
 372{
 373        return (commit->object.flags & (UNINTERESTING | BOTTOM)) != UNINTERESTING;
 374}
 375
 376/*
 377 * Return a single relevant commit from a parent list. If we are a TREESAME
 378 * commit, and this selects one of our parents, then we can safely simplify to
 379 * that parent.
 380 */
 381static struct commit *one_relevant_parent(const struct rev_info *revs,
 382                                          struct commit_list *orig)
 383{
 384        struct commit_list *list = orig;
 385        struct commit *relevant = NULL;
 386
 387        if (!orig)
 388                return NULL;
 389
 390        /*
 391         * For 1-parent commits, or if first-parent-only, then return that
 392         * first parent (even if not "relevant" by the above definition).
 393         * TREESAME will have been set purely on that parent.
 394         */
 395        if (revs->first_parent_only || !orig->next)
 396                return orig->item;
 397
 398        /*
 399         * For multi-parent commits, identify a sole relevant parent, if any.
 400         * If we have only one relevant parent, then TREESAME will be set purely
 401         * with regard to that parent, and we can simplify accordingly.
 402         *
 403         * If we have more than one relevant parent, or no relevant parents
 404         * (and multiple irrelevant ones), then we can't select a parent here
 405         * and return NULL.
 406         */
 407        while (list) {
 408                struct commit *commit = list->item;
 409                list = list->next;
 410                if (relevant_commit(commit)) {
 411                        if (relevant)
 412                                return NULL;
 413                        relevant = commit;
 414                }
 415        }
 416        return relevant;
 417}
 418
 419/*
 420 * The goal is to get REV_TREE_NEW as the result only if the
 421 * diff consists of all '+' (and no other changes), REV_TREE_OLD
 422 * if the whole diff is removal of old data, and otherwise
 423 * REV_TREE_DIFFERENT (of course if the trees are the same we
 424 * want REV_TREE_SAME).
 425 * That means that once we get to REV_TREE_DIFFERENT, we do not
 426 * have to look any further.
 427 */
 428static int tree_difference = REV_TREE_SAME;
 429
 430static void file_add_remove(struct diff_options *options,
 431                    int addremove, unsigned mode,
 432                    const unsigned char *sha1,
 433                    int sha1_valid,
 434                    const char *fullpath, unsigned dirty_submodule)
 435{
 436        int diff = addremove == '+' ? REV_TREE_NEW : REV_TREE_OLD;
 437
 438        tree_difference |= diff;
 439        if (tree_difference == REV_TREE_DIFFERENT)
 440                DIFF_OPT_SET(options, HAS_CHANGES);
 441}
 442
 443static void file_change(struct diff_options *options,
 444                 unsigned old_mode, unsigned new_mode,
 445                 const unsigned char *old_sha1,
 446                 const unsigned char *new_sha1,
 447                 int old_sha1_valid, int new_sha1_valid,
 448                 const char *fullpath,
 449                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
 450{
 451        tree_difference = REV_TREE_DIFFERENT;
 452        DIFF_OPT_SET(options, HAS_CHANGES);
 453}
 454
 455static int rev_compare_tree(struct rev_info *revs,
 456                            struct commit *parent, struct commit *commit)
 457{
 458        struct tree *t1 = parent->tree;
 459        struct tree *t2 = commit->tree;
 460
 461        if (!t1)
 462                return REV_TREE_NEW;
 463        if (!t2)
 464                return REV_TREE_OLD;
 465
 466        if (revs->simplify_by_decoration) {
 467                /*
 468                 * If we are simplifying by decoration, then the commit
 469                 * is worth showing if it has a tag pointing at it.
 470                 */
 471                if (lookup_decoration(&name_decoration, &commit->object))
 472                        return REV_TREE_DIFFERENT;
 473                /*
 474                 * A commit that is not pointed by a tag is uninteresting
 475                 * if we are not limited by path.  This means that you will
 476                 * see the usual "commits that touch the paths" plus any
 477                 * tagged commit by specifying both --simplify-by-decoration
 478                 * and pathspec.
 479                 */
 480                if (!revs->prune_data.nr)
 481                        return REV_TREE_SAME;
 482        }
 483
 484        tree_difference = REV_TREE_SAME;
 485        DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 486        if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
 487                           &revs->pruning) < 0)
 488                return REV_TREE_DIFFERENT;
 489        return tree_difference;
 490}
 491
 492static int rev_same_tree_as_empty(struct rev_info *revs, struct commit *commit)
 493{
 494        int retval;
 495        void *tree;
 496        unsigned long size;
 497        struct tree_desc empty, real;
 498        struct tree *t1 = commit->tree;
 499
 500        if (!t1)
 501                return 0;
 502
 503        tree = read_object_with_reference(t1->object.sha1, tree_type, &size, NULL);
 504        if (!tree)
 505                return 0;
 506        init_tree_desc(&real, tree, size);
 507        init_tree_desc(&empty, "", 0);
 508
 509        tree_difference = REV_TREE_SAME;
 510        DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 511        retval = diff_tree(&empty, &real, "", &revs->pruning);
 512        free(tree);
 513
 514        return retval >= 0 && (tree_difference == REV_TREE_SAME);
 515}
 516
 517struct treesame_state {
 518        unsigned int nparents;
 519        unsigned char treesame[FLEX_ARRAY];
 520};
 521
 522static struct treesame_state *initialise_treesame(struct rev_info *revs, struct commit *commit)
 523{
 524        unsigned n = commit_list_count(commit->parents);
 525        struct treesame_state *st = xcalloc(1, sizeof(*st) + n);
 526        st->nparents = n;
 527        add_decoration(&revs->treesame, &commit->object, st);
 528        return st;
 529}
 530
 531/*
 532 * Must be called immediately after removing the nth_parent from a commit's
 533 * parent list, if we are maintaining the per-parent treesame[] decoration.
 534 * This does not recalculate the master TREESAME flag - update_treesame()
 535 * should be called to update it after a sequence of treesame[] modifications
 536 * that may have affected it.
 537 */
 538static int compact_treesame(struct rev_info *revs, struct commit *commit, unsigned nth_parent)
 539{
 540        struct treesame_state *st;
 541        int old_same;
 542
 543        if (!commit->parents) {
 544                /*
 545                 * Have just removed the only parent from a non-merge.
 546                 * Different handling, as we lack decoration.
 547                 */
 548                if (nth_parent != 0)
 549                        die("compact_treesame %u", nth_parent);
 550                old_same = !!(commit->object.flags & TREESAME);
 551                if (rev_same_tree_as_empty(revs, commit))
 552                        commit->object.flags |= TREESAME;
 553                else
 554                        commit->object.flags &= ~TREESAME;
 555                return old_same;
 556        }
 557
 558        st = lookup_decoration(&revs->treesame, &commit->object);
 559        if (!st || nth_parent >= st->nparents)
 560                die("compact_treesame %u", nth_parent);
 561
 562        old_same = st->treesame[nth_parent];
 563        memmove(st->treesame + nth_parent,
 564                st->treesame + nth_parent + 1,
 565                st->nparents - nth_parent - 1);
 566
 567        /*
 568         * If we've just become a non-merge commit, update TREESAME
 569         * immediately, and remove the no-longer-needed decoration.
 570         * If still a merge, defer update until update_treesame().
 571         */
 572        if (--st->nparents == 1) {
 573                if (commit->parents->next)
 574                        die("compact_treesame parents mismatch");
 575                if (st->treesame[0] && revs->dense)
 576                        commit->object.flags |= TREESAME;
 577                else
 578                        commit->object.flags &= ~TREESAME;
 579                free(add_decoration(&revs->treesame, &commit->object, NULL));
 580        }
 581
 582        return old_same;
 583}
 584
 585static unsigned update_treesame(struct rev_info *revs, struct commit *commit)
 586{
 587        if (commit->parents && commit->parents->next) {
 588                unsigned n;
 589                struct treesame_state *st;
 590                struct commit_list *p;
 591                unsigned relevant_parents;
 592                unsigned relevant_change, irrelevant_change;
 593
 594                st = lookup_decoration(&revs->treesame, &commit->object);
 595                if (!st)
 596                        die("update_treesame %s", sha1_to_hex(commit->object.sha1));
 597                relevant_parents = 0;
 598                relevant_change = irrelevant_change = 0;
 599                for (p = commit->parents, n = 0; p; n++, p = p->next) {
 600                        if (relevant_commit(p->item)) {
 601                                relevant_change |= !st->treesame[n];
 602                                relevant_parents++;
 603                        } else
 604                                irrelevant_change |= !st->treesame[n];
 605                }
 606                if (relevant_parents ? relevant_change : irrelevant_change)
 607                        commit->object.flags &= ~TREESAME;
 608                else
 609                        commit->object.flags |= TREESAME;
 610        }
 611
 612        return commit->object.flags & TREESAME;
 613}
 614
 615static inline int limiting_can_increase_treesame(const struct rev_info *revs)
 616{
 617        /*
 618         * TREESAME is irrelevant unless prune && dense;
 619         * if simplify_history is set, we can't have a mixture of TREESAME and
 620         *    !TREESAME INTERESTING parents (and we don't have treesame[]
 621         *    decoration anyway);
 622         * if first_parent_only is set, then the TREESAME flag is locked
 623         *    against the first parent (and again we lack treesame[] decoration).
 624         */
 625        return revs->prune && revs->dense &&
 626               !revs->simplify_history &&
 627               !revs->first_parent_only;
 628}
 629
 630static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 631{
 632        struct commit_list **pp, *parent;
 633        struct treesame_state *ts = NULL;
 634        int relevant_change = 0, irrelevant_change = 0;
 635        int relevant_parents, nth_parent;
 636
 637        /*
 638         * If we don't do pruning, everything is interesting
 639         */
 640        if (!revs->prune)
 641                return;
 642
 643        if (!commit->tree)
 644                return;
 645
 646        if (!commit->parents) {
 647                if (rev_same_tree_as_empty(revs, commit))
 648                        commit->object.flags |= TREESAME;
 649                return;
 650        }
 651
 652        /*
 653         * Normal non-merge commit? If we don't want to make the
 654         * history dense, we consider it always to be a change..
 655         */
 656        if (!revs->dense && !commit->parents->next)
 657                return;
 658
 659        for (pp = &commit->parents, nth_parent = 0, relevant_parents = 0;
 660             (parent = *pp) != NULL;
 661             pp = &parent->next, nth_parent++) {
 662                struct commit *p = parent->item;
 663                if (relevant_commit(p))
 664                        relevant_parents++;
 665
 666                if (nth_parent == 1) {
 667                        /*
 668                         * This our second loop iteration - so we now know
 669                         * we're dealing with a merge.
 670                         *
 671                         * Do not compare with later parents when we care only about
 672                         * the first parent chain, in order to avoid derailing the
 673                         * traversal to follow a side branch that brought everything
 674                         * in the path we are limited to by the pathspec.
 675                         */
 676                        if (revs->first_parent_only)
 677                                break;
 678                        /*
 679                         * If this will remain a potentially-simplifiable
 680                         * merge, remember per-parent treesame if needed.
 681                         * Initialise the array with the comparison from our
 682                         * first iteration.
 683                         */
 684                        if (revs->treesame.name &&
 685                            !revs->simplify_history &&
 686                            !(commit->object.flags & UNINTERESTING)) {
 687                                ts = initialise_treesame(revs, commit);
 688                                if (!(irrelevant_change || relevant_change))
 689                                        ts->treesame[0] = 1;
 690                        }
 691                }
 692                if (parse_commit(p) < 0)
 693                        die("cannot simplify commit %s (because of %s)",
 694                            sha1_to_hex(commit->object.sha1),
 695                            sha1_to_hex(p->object.sha1));
 696                switch (rev_compare_tree(revs, p, commit)) {
 697                case REV_TREE_SAME:
 698                        if (!revs->simplify_history || !relevant_commit(p)) {
 699                                /* Even if a merge with an uninteresting
 700                                 * side branch brought the entire change
 701                                 * we are interested in, we do not want
 702                                 * to lose the other branches of this
 703                                 * merge, so we just keep going.
 704                                 */
 705                                if (ts)
 706                                        ts->treesame[nth_parent] = 1;
 707                                continue;
 708                        }
 709                        parent->next = NULL;
 710                        commit->parents = parent;
 711                        commit->object.flags |= TREESAME;
 712                        return;
 713
 714                case REV_TREE_NEW:
 715                        if (revs->remove_empty_trees &&
 716                            rev_same_tree_as_empty(revs, p)) {
 717                                /* We are adding all the specified
 718                                 * paths from this parent, so the
 719                                 * history beyond this parent is not
 720                                 * interesting.  Remove its parents
 721                                 * (they are grandparents for us).
 722                                 * IOW, we pretend this parent is a
 723                                 * "root" commit.
 724                                 */
 725                                if (parse_commit(p) < 0)
 726                                        die("cannot simplify commit %s (invalid %s)",
 727                                            sha1_to_hex(commit->object.sha1),
 728                                            sha1_to_hex(p->object.sha1));
 729                                p->parents = NULL;
 730                        }
 731                /* fallthrough */
 732                case REV_TREE_OLD:
 733                case REV_TREE_DIFFERENT:
 734                        if (relevant_commit(p))
 735                                relevant_change = 1;
 736                        else
 737                                irrelevant_change = 1;
 738                        continue;
 739                }
 740                die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
 741        }
 742
 743        /*
 744         * TREESAME is straightforward for single-parent commits. For merge
 745         * commits, it is most useful to define it so that "irrelevant"
 746         * parents cannot make us !TREESAME - if we have any relevant
 747         * parents, then we only consider TREESAMEness with respect to them,
 748         * allowing irrelevant merges from uninteresting branches to be
 749         * simplified away. Only if we have only irrelevant parents do we
 750         * base TREESAME on them. Note that this logic is replicated in
 751         * update_treesame, which should be kept in sync.
 752         */
 753        if (relevant_parents ? !relevant_change : !irrelevant_change)
 754                commit->object.flags |= TREESAME;
 755}
 756
 757static void commit_list_insert_by_date_cached(struct commit *p, struct commit_list **head,
 758                    struct commit_list *cached_base, struct commit_list **cache)
 759{
 760        struct commit_list *new_entry;
 761
 762        if (cached_base && p->date < cached_base->item->date)
 763                new_entry = commit_list_insert_by_date(p, &cached_base->next);
 764        else
 765                new_entry = commit_list_insert_by_date(p, head);
 766
 767        if (cache && (!*cache || p->date < (*cache)->item->date))
 768                *cache = new_entry;
 769}
 770
 771static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
 772                    struct commit_list **list, struct commit_list **cache_ptr)
 773{
 774        struct commit_list *parent = commit->parents;
 775        unsigned left_flag;
 776        struct commit_list *cached_base = cache_ptr ? *cache_ptr : NULL;
 777
 778        if (commit->object.flags & ADDED)
 779                return 0;
 780        commit->object.flags |= ADDED;
 781
 782        /*
 783         * If the commit is uninteresting, don't try to
 784         * prune parents - we want the maximal uninteresting
 785         * set.
 786         *
 787         * Normally we haven't parsed the parent
 788         * yet, so we won't have a parent of a parent
 789         * here. However, it may turn out that we've
 790         * reached this commit some other way (where it
 791         * wasn't uninteresting), in which case we need
 792         * to mark its parents recursively too..
 793         */
 794        if (commit->object.flags & UNINTERESTING) {
 795                while (parent) {
 796                        struct commit *p = parent->item;
 797                        parent = parent->next;
 798                        if (p)
 799                                p->object.flags |= UNINTERESTING;
 800                        if (parse_commit(p) < 0)
 801                                continue;
 802                        if (p->parents)
 803                                mark_parents_uninteresting(p);
 804                        if (p->object.flags & SEEN)
 805                                continue;
 806                        p->object.flags |= SEEN;
 807                        commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
 808                }
 809                return 0;
 810        }
 811
 812        /*
 813         * Ok, the commit wasn't uninteresting. Try to
 814         * simplify the commit history and find the parent
 815         * that has no differences in the path set if one exists.
 816         */
 817        try_to_simplify_commit(revs, commit);
 818
 819        if (revs->no_walk)
 820                return 0;
 821
 822        left_flag = (commit->object.flags & SYMMETRIC_LEFT);
 823
 824        for (parent = commit->parents; parent; parent = parent->next) {
 825                struct commit *p = parent->item;
 826
 827                if (parse_commit(p) < 0)
 828                        return -1;
 829                if (revs->show_source && !p->util)
 830                        p->util = commit->util;
 831                p->object.flags |= left_flag;
 832                if (!(p->object.flags & SEEN)) {
 833                        p->object.flags |= SEEN;
 834                        commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
 835                }
 836                if (revs->first_parent_only)
 837                        break;
 838        }
 839        return 0;
 840}
 841
 842static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
 843{
 844        struct commit_list *p;
 845        int left_count = 0, right_count = 0;
 846        int left_first;
 847        struct patch_ids ids;
 848        unsigned cherry_flag;
 849
 850        /* First count the commits on the left and on the right */
 851        for (p = list; p; p = p->next) {
 852                struct commit *commit = p->item;
 853                unsigned flags = commit->object.flags;
 854                if (flags & BOUNDARY)
 855                        ;
 856                else if (flags & SYMMETRIC_LEFT)
 857                        left_count++;
 858                else
 859                        right_count++;
 860        }
 861
 862        if (!left_count || !right_count)
 863                return;
 864
 865        left_first = left_count < right_count;
 866        init_patch_ids(&ids);
 867        ids.diffopts.pathspec = revs->diffopt.pathspec;
 868
 869        /* Compute patch-ids for one side */
 870        for (p = list; p; p = p->next) {
 871                struct commit *commit = p->item;
 872                unsigned flags = commit->object.flags;
 873
 874                if (flags & BOUNDARY)
 875                        continue;
 876                /*
 877                 * If we have fewer left, left_first is set and we omit
 878                 * commits on the right branch in this loop.  If we have
 879                 * fewer right, we skip the left ones.
 880                 */
 881                if (left_first != !!(flags & SYMMETRIC_LEFT))
 882                        continue;
 883                commit->util = add_commit_patch_id(commit, &ids);
 884        }
 885
 886        /* either cherry_mark or cherry_pick are true */
 887        cherry_flag = revs->cherry_mark ? PATCHSAME : SHOWN;
 888
 889        /* Check the other side */
 890        for (p = list; p; p = p->next) {
 891                struct commit *commit = p->item;
 892                struct patch_id *id;
 893                unsigned flags = commit->object.flags;
 894
 895                if (flags & BOUNDARY)
 896                        continue;
 897                /*
 898                 * If we have fewer left, left_first is set and we omit
 899                 * commits on the left branch in this loop.
 900                 */
 901                if (left_first == !!(flags & SYMMETRIC_LEFT))
 902                        continue;
 903
 904                /*
 905                 * Have we seen the same patch id?
 906                 */
 907                id = has_commit_patch_id(commit, &ids);
 908                if (!id)
 909                        continue;
 910                id->seen = 1;
 911                commit->object.flags |= cherry_flag;
 912        }
 913
 914        /* Now check the original side for seen ones */
 915        for (p = list; p; p = p->next) {
 916                struct commit *commit = p->item;
 917                struct patch_id *ent;
 918
 919                ent = commit->util;
 920                if (!ent)
 921                        continue;
 922                if (ent->seen)
 923                        commit->object.flags |= cherry_flag;
 924                commit->util = NULL;
 925        }
 926
 927        free_patch_ids(&ids);
 928}
 929
 930/* How many extra uninteresting commits we want to see.. */
 931#define SLOP 5
 932
 933static int still_interesting(struct commit_list *src, unsigned long date, int slop)
 934{
 935        /*
 936         * No source list at all? We're definitely done..
 937         */
 938        if (!src)
 939                return 0;
 940
 941        /*
 942         * Does the destination list contain entries with a date
 943         * before the source list? Definitely _not_ done.
 944         */
 945        if (date <= src->item->date)
 946                return SLOP;
 947
 948        /*
 949         * Does the source list still have interesting commits in
 950         * it? Definitely not done..
 951         */
 952        if (!everybody_uninteresting(src))
 953                return SLOP;
 954
 955        /* Ok, we're closing in.. */
 956        return slop-1;
 957}
 958
 959/*
 960 * "rev-list --ancestry-path A..B" computes commits that are ancestors
 961 * of B but not ancestors of A but further limits the result to those
 962 * that are descendants of A.  This takes the list of bottom commits and
 963 * the result of "A..B" without --ancestry-path, and limits the latter
 964 * further to the ones that can reach one of the commits in "bottom".
 965 */
 966static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *list)
 967{
 968        struct commit_list *p;
 969        struct commit_list *rlist = NULL;
 970        int made_progress;
 971
 972        /*
 973         * Reverse the list so that it will be likely that we would
 974         * process parents before children.
 975         */
 976        for (p = list; p; p = p->next)
 977                commit_list_insert(p->item, &rlist);
 978
 979        for (p = bottom; p; p = p->next)
 980                p->item->object.flags |= TMP_MARK;
 981
 982        /*
 983         * Mark the ones that can reach bottom commits in "list",
 984         * in a bottom-up fashion.
 985         */
 986        do {
 987                made_progress = 0;
 988                for (p = rlist; p; p = p->next) {
 989                        struct commit *c = p->item;
 990                        struct commit_list *parents;
 991                        if (c->object.flags & (TMP_MARK | UNINTERESTING))
 992                                continue;
 993                        for (parents = c->parents;
 994                             parents;
 995                             parents = parents->next) {
 996                                if (!(parents->item->object.flags & TMP_MARK))
 997                                        continue;
 998                                c->object.flags |= TMP_MARK;
 999                                made_progress = 1;
1000                                break;
1001                        }
1002                }
1003        } while (made_progress);
1004
1005        /*
1006         * NEEDSWORK: decide if we want to remove parents that are
1007         * not marked with TMP_MARK from commit->parents for commits
1008         * in the resulting list.  We may not want to do that, though.
1009         */
1010
1011        /*
1012         * The ones that are not marked with TMP_MARK are uninteresting
1013         */
1014        for (p = list; p; p = p->next) {
1015                struct commit *c = p->item;
1016                if (c->object.flags & TMP_MARK)
1017                        continue;
1018                c->object.flags |= UNINTERESTING;
1019        }
1020
1021        /* We are done with the TMP_MARK */
1022        for (p = list; p; p = p->next)
1023                p->item->object.flags &= ~TMP_MARK;
1024        for (p = bottom; p; p = p->next)
1025                p->item->object.flags &= ~TMP_MARK;
1026        free_commit_list(rlist);
1027}
1028
1029/*
1030 * Before walking the history, keep the set of "negative" refs the
1031 * caller has asked to exclude.
1032 *
1033 * This is used to compute "rev-list --ancestry-path A..B", as we need
1034 * to filter the result of "A..B" further to the ones that can actually
1035 * reach A.
1036 */
1037static struct commit_list *collect_bottom_commits(struct commit_list *list)
1038{
1039        struct commit_list *elem, *bottom = NULL;
1040        for (elem = list; elem; elem = elem->next)
1041                if (elem->item->object.flags & BOTTOM)
1042                        commit_list_insert(elem->item, &bottom);
1043        return bottom;
1044}
1045
1046/* Assumes either left_only or right_only is set */
1047static void limit_left_right(struct commit_list *list, struct rev_info *revs)
1048{
1049        struct commit_list *p;
1050
1051        for (p = list; p; p = p->next) {
1052                struct commit *commit = p->item;
1053
1054                if (revs->right_only) {
1055                        if (commit->object.flags & SYMMETRIC_LEFT)
1056                                commit->object.flags |= SHOWN;
1057                } else  /* revs->left_only is set */
1058                        if (!(commit->object.flags & SYMMETRIC_LEFT))
1059                                commit->object.flags |= SHOWN;
1060        }
1061}
1062
1063static int limit_list(struct rev_info *revs)
1064{
1065        int slop = SLOP;
1066        unsigned long date = ~0ul;
1067        struct commit_list *list = revs->commits;
1068        struct commit_list *newlist = NULL;
1069        struct commit_list **p = &newlist;
1070        struct commit_list *bottom = NULL;
1071
1072        if (revs->ancestry_path) {
1073                bottom = collect_bottom_commits(list);
1074                if (!bottom)
1075                        die("--ancestry-path given but there are no bottom commits");
1076        }
1077
1078        while (list) {
1079                struct commit_list *entry = list;
1080                struct commit *commit = list->item;
1081                struct object *obj = &commit->object;
1082                show_early_output_fn_t show;
1083
1084                list = list->next;
1085                free(entry);
1086
1087                if (revs->max_age != -1 && (commit->date < revs->max_age))
1088                        obj->flags |= UNINTERESTING;
1089                if (add_parents_to_list(revs, commit, &list, NULL) < 0)
1090                        return -1;
1091                if (obj->flags & UNINTERESTING) {
1092                        mark_parents_uninteresting(commit);
1093                        if (revs->show_all)
1094                                p = &commit_list_insert(commit, p)->next;
1095                        slop = still_interesting(list, date, slop);
1096                        if (slop)
1097                                continue;
1098                        /* If showing all, add the whole pending list to the end */
1099                        if (revs->show_all)
1100                                *p = list;
1101                        break;
1102                }
1103                if (revs->min_age != -1 && (commit->date > revs->min_age))
1104                        continue;
1105                date = commit->date;
1106                p = &commit_list_insert(commit, p)->next;
1107
1108                show = show_early_output;
1109                if (!show)
1110                        continue;
1111
1112                show(revs, newlist);
1113                show_early_output = NULL;
1114        }
1115        if (revs->cherry_pick || revs->cherry_mark)
1116                cherry_pick_list(newlist, revs);
1117
1118        if (revs->left_only || revs->right_only)
1119                limit_left_right(newlist, revs);
1120
1121        if (bottom) {
1122                limit_to_ancestry(bottom, newlist);
1123                free_commit_list(bottom);
1124        }
1125
1126        /*
1127         * Check if any commits have become TREESAME by some of their parents
1128         * becoming UNINTERESTING.
1129         */
1130        if (limiting_can_increase_treesame(revs))
1131                for (list = newlist; list; list = list->next) {
1132                        struct commit *c = list->item;
1133                        if (c->object.flags & (UNINTERESTING | TREESAME))
1134                                continue;
1135                        update_treesame(revs, c);
1136                }
1137
1138        revs->commits = newlist;
1139        return 0;
1140}
1141
1142/*
1143 * Add an entry to refs->cmdline with the specified information.
1144 * *name is copied.
1145 */
1146static void add_rev_cmdline(struct rev_info *revs,
1147                            struct object *item,
1148                            const char *name,
1149                            int whence,
1150                            unsigned flags)
1151{
1152        struct rev_cmdline_info *info = &revs->cmdline;
1153        int nr = info->nr;
1154
1155        ALLOC_GROW(info->rev, nr + 1, info->alloc);
1156        info->rev[nr].item = item;
1157        info->rev[nr].name = xstrdup(name);
1158        info->rev[nr].whence = whence;
1159        info->rev[nr].flags = flags;
1160        info->nr++;
1161}
1162
1163static void add_rev_cmdline_list(struct rev_info *revs,
1164                                 struct commit_list *commit_list,
1165                                 int whence,
1166                                 unsigned flags)
1167{
1168        while (commit_list) {
1169                struct object *object = &commit_list->item->object;
1170                add_rev_cmdline(revs, object, sha1_to_hex(object->sha1),
1171                                whence, flags);
1172                commit_list = commit_list->next;
1173        }
1174}
1175
1176struct all_refs_cb {
1177        int all_flags;
1178        int warned_bad_reflog;
1179        struct rev_info *all_revs;
1180        const char *name_for_errormsg;
1181};
1182
1183static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1184{
1185        struct all_refs_cb *cb = cb_data;
1186        struct object *object = get_reference(cb->all_revs, path, sha1,
1187                                              cb->all_flags);
1188        add_rev_cmdline(cb->all_revs, object, path, REV_CMD_REF, cb->all_flags);
1189        add_pending_sha1(cb->all_revs, path, sha1, cb->all_flags);
1190        return 0;
1191}
1192
1193static void init_all_refs_cb(struct all_refs_cb *cb, struct rev_info *revs,
1194        unsigned flags)
1195{
1196        cb->all_revs = revs;
1197        cb->all_flags = flags;
1198}
1199
1200static void handle_refs(const char *submodule, struct rev_info *revs, unsigned flags,
1201                int (*for_each)(const char *, each_ref_fn, void *))
1202{
1203        struct all_refs_cb cb;
1204        init_all_refs_cb(&cb, revs, flags);
1205        for_each(submodule, handle_one_ref, &cb);
1206}
1207
1208static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
1209{
1210        struct all_refs_cb *cb = cb_data;
1211        if (!is_null_sha1(sha1)) {
1212                struct object *o = parse_object(sha1);
1213                if (o) {
1214                        o->flags |= cb->all_flags;
1215                        /* ??? CMDLINEFLAGS ??? */
1216                        add_pending_object(cb->all_revs, o, "");
1217                }
1218                else if (!cb->warned_bad_reflog) {
1219                        warning("reflog of '%s' references pruned commits",
1220                                cb->name_for_errormsg);
1221                        cb->warned_bad_reflog = 1;
1222                }
1223        }
1224}
1225
1226static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
1227                const char *email, unsigned long timestamp, int tz,
1228                const char *message, void *cb_data)
1229{
1230        handle_one_reflog_commit(osha1, cb_data);
1231        handle_one_reflog_commit(nsha1, cb_data);
1232        return 0;
1233}
1234
1235static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1236{
1237        struct all_refs_cb *cb = cb_data;
1238        cb->warned_bad_reflog = 0;
1239        cb->name_for_errormsg = path;
1240        for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
1241        return 0;
1242}
1243
1244static void handle_reflog(struct rev_info *revs, unsigned flags)
1245{
1246        struct all_refs_cb cb;
1247        cb.all_revs = revs;
1248        cb.all_flags = flags;
1249        for_each_reflog(handle_one_reflog, &cb);
1250}
1251
1252static int add_parents_only(struct rev_info *revs, const char *arg_, int flags)
1253{
1254        unsigned char sha1[20];
1255        struct object *it;
1256        struct commit *commit;
1257        struct commit_list *parents;
1258        const char *arg = arg_;
1259
1260        if (*arg == '^') {
1261                flags ^= UNINTERESTING | BOTTOM;
1262                arg++;
1263        }
1264        if (get_sha1_committish(arg, sha1))
1265                return 0;
1266        while (1) {
1267                it = get_reference(revs, arg, sha1, 0);
1268                if (!it && revs->ignore_missing)
1269                        return 0;
1270                if (it->type != OBJ_TAG)
1271                        break;
1272                if (!((struct tag*)it)->tagged)
1273                        return 0;
1274                hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
1275        }
1276        if (it->type != OBJ_COMMIT)
1277                return 0;
1278        commit = (struct commit *)it;
1279        for (parents = commit->parents; parents; parents = parents->next) {
1280                it = &parents->item->object;
1281                it->flags |= flags;
1282                add_rev_cmdline(revs, it, arg_, REV_CMD_PARENTS_ONLY, flags);
1283                add_pending_object(revs, it, arg);
1284        }
1285        return 1;
1286}
1287
1288void init_revisions(struct rev_info *revs, const char *prefix)
1289{
1290        memset(revs, 0, sizeof(*revs));
1291
1292        revs->abbrev = DEFAULT_ABBREV;
1293        revs->ignore_merges = 1;
1294        revs->simplify_history = 1;
1295        DIFF_OPT_SET(&revs->pruning, RECURSIVE);
1296        DIFF_OPT_SET(&revs->pruning, QUICK);
1297        revs->pruning.add_remove = file_add_remove;
1298        revs->pruning.change = file_change;
1299        revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
1300        revs->dense = 1;
1301        revs->prefix = prefix;
1302        revs->max_age = -1;
1303        revs->min_age = -1;
1304        revs->skip_count = -1;
1305        revs->max_count = -1;
1306        revs->max_parents = -1;
1307
1308        revs->commit_format = CMIT_FMT_DEFAULT;
1309
1310        init_grep_defaults();
1311        grep_init(&revs->grep_filter, prefix);
1312        revs->grep_filter.status_only = 1;
1313        revs->grep_filter.regflags = REG_NEWLINE;
1314
1315        diff_setup(&revs->diffopt);
1316        if (prefix && !revs->diffopt.prefix) {
1317                revs->diffopt.prefix = prefix;
1318                revs->diffopt.prefix_length = strlen(prefix);
1319        }
1320
1321        revs->notes_opt.use_default_notes = -1;
1322}
1323
1324static void add_pending_commit_list(struct rev_info *revs,
1325                                    struct commit_list *commit_list,
1326                                    unsigned int flags)
1327{
1328        while (commit_list) {
1329                struct object *object = &commit_list->item->object;
1330                object->flags |= flags;
1331                add_pending_object(revs, object, sha1_to_hex(object->sha1));
1332                commit_list = commit_list->next;
1333        }
1334}
1335
1336static void prepare_show_merge(struct rev_info *revs)
1337{
1338        struct commit_list *bases;
1339        struct commit *head, *other;
1340        unsigned char sha1[20];
1341        const char **prune = NULL;
1342        int i, prune_num = 1; /* counting terminating NULL */
1343
1344        if (get_sha1("HEAD", sha1))
1345                die("--merge without HEAD?");
1346        head = lookup_commit_or_die(sha1, "HEAD");
1347        if (get_sha1("MERGE_HEAD", sha1))
1348                die("--merge without MERGE_HEAD?");
1349        other = lookup_commit_or_die(sha1, "MERGE_HEAD");
1350        add_pending_object(revs, &head->object, "HEAD");
1351        add_pending_object(revs, &other->object, "MERGE_HEAD");
1352        bases = get_merge_bases(head, other, 1);
1353        add_rev_cmdline_list(revs, bases, REV_CMD_MERGE_BASE, UNINTERESTING | BOTTOM);
1354        add_pending_commit_list(revs, bases, UNINTERESTING | BOTTOM);
1355        free_commit_list(bases);
1356        head->object.flags |= SYMMETRIC_LEFT;
1357
1358        if (!active_nr)
1359                read_cache();
1360        for (i = 0; i < active_nr; i++) {
1361                const struct cache_entry *ce = active_cache[i];
1362                if (!ce_stage(ce))
1363                        continue;
1364                if (ce_path_match(ce, &revs->prune_data)) {
1365                        prune_num++;
1366                        prune = xrealloc(prune, sizeof(*prune) * prune_num);
1367                        prune[prune_num-2] = ce->name;
1368                        prune[prune_num-1] = NULL;
1369                }
1370                while ((i+1 < active_nr) &&
1371                       ce_same_name(ce, active_cache[i+1]))
1372                        i++;
1373        }
1374        free_pathspec(&revs->prune_data);
1375        parse_pathspec(&revs->prune_data, PATHSPEC_ALL_MAGIC,
1376                       PATHSPEC_PREFER_FULL, "", prune);
1377        revs->limited = 1;
1378}
1379
1380int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsigned revarg_opt)
1381{
1382        struct object_context oc;
1383        char *dotdot;
1384        struct object *object;
1385        unsigned char sha1[20];
1386        int local_flags;
1387        const char *arg = arg_;
1388        int cant_be_filename = revarg_opt & REVARG_CANNOT_BE_FILENAME;
1389        unsigned get_sha1_flags = 0;
1390
1391        flags = flags & UNINTERESTING ? flags | BOTTOM : flags & ~BOTTOM;
1392
1393        dotdot = strstr(arg, "..");
1394        if (dotdot) {
1395                unsigned char from_sha1[20];
1396                const char *next = dotdot + 2;
1397                const char *this = arg;
1398                int symmetric = *next == '.';
1399                unsigned int flags_exclude = flags ^ (UNINTERESTING | BOTTOM);
1400                static const char head_by_default[] = "HEAD";
1401                unsigned int a_flags;
1402
1403                *dotdot = 0;
1404                next += symmetric;
1405
1406                if (!*next)
1407                        next = head_by_default;
1408                if (dotdot == arg)
1409                        this = head_by_default;
1410                if (this == head_by_default && next == head_by_default &&
1411                    !symmetric) {
1412                        /*
1413                         * Just ".."?  That is not a range but the
1414                         * pathspec for the parent directory.
1415                         */
1416                        if (!cant_be_filename) {
1417                                *dotdot = '.';
1418                                return -1;
1419                        }
1420                }
1421                if (!get_sha1_committish(this, from_sha1) &&
1422                    !get_sha1_committish(next, sha1)) {
1423                        struct object *a_obj, *b_obj;
1424
1425                        if (!cant_be_filename) {
1426                                *dotdot = '.';
1427                                verify_non_filename(revs->prefix, arg);
1428                        }
1429
1430                        a_obj = parse_object(from_sha1);
1431                        b_obj = parse_object(sha1);
1432                        if (!a_obj || !b_obj) {
1433                        missing:
1434                                if (revs->ignore_missing)
1435                                        return 0;
1436                                die(symmetric
1437                                    ? "Invalid symmetric difference expression %s"
1438                                    : "Invalid revision range %s", arg);
1439                        }
1440
1441                        if (!symmetric) {
1442                                /* just A..B */
1443                                a_flags = flags_exclude;
1444                        } else {
1445                                /* A...B -- find merge bases between the two */
1446                                struct commit *a, *b;
1447                                struct commit_list *exclude;
1448
1449                                a = (a_obj->type == OBJ_COMMIT
1450                                     ? (struct commit *)a_obj
1451                                     : lookup_commit_reference(a_obj->sha1));
1452                                b = (b_obj->type == OBJ_COMMIT
1453                                     ? (struct commit *)b_obj
1454                                     : lookup_commit_reference(b_obj->sha1));
1455                                if (!a || !b)
1456                                        goto missing;
1457                                exclude = get_merge_bases(a, b, 1);
1458                                add_rev_cmdline_list(revs, exclude,
1459                                                     REV_CMD_MERGE_BASE,
1460                                                     flags_exclude);
1461                                add_pending_commit_list(revs, exclude,
1462                                                        flags_exclude);
1463                                free_commit_list(exclude);
1464
1465                                a_flags = flags | SYMMETRIC_LEFT;
1466                        }
1467
1468                        a_obj->flags |= a_flags;
1469                        b_obj->flags |= flags;
1470                        add_rev_cmdline(revs, a_obj, this,
1471                                        REV_CMD_LEFT, a_flags);
1472                        add_rev_cmdline(revs, b_obj, next,
1473                                        REV_CMD_RIGHT, flags);
1474                        add_pending_object(revs, a_obj, this);
1475                        add_pending_object(revs, b_obj, next);
1476                        return 0;
1477                }
1478                *dotdot = '.';
1479        }
1480        dotdot = strstr(arg, "^@");
1481        if (dotdot && !dotdot[2]) {
1482                *dotdot = 0;
1483                if (add_parents_only(revs, arg, flags))
1484                        return 0;
1485                *dotdot = '^';
1486        }
1487        dotdot = strstr(arg, "^!");
1488        if (dotdot && !dotdot[2]) {
1489                *dotdot = 0;
1490                if (!add_parents_only(revs, arg, flags ^ (UNINTERESTING | BOTTOM)))
1491                        *dotdot = '^';
1492        }
1493
1494        local_flags = 0;
1495        if (*arg == '^') {
1496                local_flags = UNINTERESTING | BOTTOM;
1497                arg++;
1498        }
1499
1500        if (revarg_opt & REVARG_COMMITTISH)
1501                get_sha1_flags = GET_SHA1_COMMITTISH;
1502
1503        if (get_sha1_with_context(arg, get_sha1_flags, sha1, &oc))
1504                return revs->ignore_missing ? 0 : -1;
1505        if (!cant_be_filename)
1506                verify_non_filename(revs->prefix, arg);
1507        object = get_reference(revs, arg, sha1, flags ^ local_flags);
1508        add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
1509        add_pending_object_with_mode(revs, object, arg, oc.mode);
1510        return 0;
1511}
1512
1513struct cmdline_pathspec {
1514        int alloc;
1515        int nr;
1516        const char **path;
1517};
1518
1519static void append_prune_data(struct cmdline_pathspec *prune, const char **av)
1520{
1521        while (*av) {
1522                ALLOC_GROW(prune->path, prune->nr+1, prune->alloc);
1523                prune->path[prune->nr++] = *(av++);
1524        }
1525}
1526
1527static void read_pathspec_from_stdin(struct rev_info *revs, struct strbuf *sb,
1528                                     struct cmdline_pathspec *prune)
1529{
1530        while (strbuf_getwholeline(sb, stdin, '\n') != EOF) {
1531                int len = sb->len;
1532                if (len && sb->buf[len - 1] == '\n')
1533                        sb->buf[--len] = '\0';
1534                ALLOC_GROW(prune->path, prune->nr+1, prune->alloc);
1535                prune->path[prune->nr++] = xstrdup(sb->buf);
1536        }
1537}
1538
1539static void read_revisions_from_stdin(struct rev_info *revs,
1540                                      struct cmdline_pathspec *prune)
1541{
1542        struct strbuf sb;
1543        int seen_dashdash = 0;
1544
1545        strbuf_init(&sb, 1000);
1546        while (strbuf_getwholeline(&sb, stdin, '\n') != EOF) {
1547                int len = sb.len;
1548                if (len && sb.buf[len - 1] == '\n')
1549                        sb.buf[--len] = '\0';
1550                if (!len)
1551                        break;
1552                if (sb.buf[0] == '-') {
1553                        if (len == 2 && sb.buf[1] == '-') {
1554                                seen_dashdash = 1;
1555                                break;
1556                        }
1557                        die("options not supported in --stdin mode");
1558                }
1559                if (handle_revision_arg(sb.buf, revs, 0,
1560                                        REVARG_CANNOT_BE_FILENAME))
1561                        die("bad revision '%s'", sb.buf);
1562        }
1563        if (seen_dashdash)
1564                read_pathspec_from_stdin(revs, &sb, prune);
1565        strbuf_release(&sb);
1566}
1567
1568static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
1569{
1570        append_grep_pattern(&revs->grep_filter, ptn, "command line", 0, what);
1571}
1572
1573static void add_header_grep(struct rev_info *revs, enum grep_header_field field, const char *pattern)
1574{
1575        append_header_grep_pattern(&revs->grep_filter, field, pattern);
1576}
1577
1578static void add_message_grep(struct rev_info *revs, const char *pattern)
1579{
1580        add_grep(revs, pattern, GREP_PATTERN_BODY);
1581}
1582
1583static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
1584                               int *unkc, const char **unkv)
1585{
1586        const char *arg = argv[0];
1587        const char *optarg;
1588        int argcount;
1589
1590        /* pseudo revision arguments */
1591        if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
1592            !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
1593            !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
1594            !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
1595            !strcmp(arg, "--bisect") || !prefixcmp(arg, "--glob=") ||
1596            !prefixcmp(arg, "--branches=") || !prefixcmp(arg, "--tags=") ||
1597            !prefixcmp(arg, "--remotes=") || !prefixcmp(arg, "--no-walk="))
1598        {
1599                unkv[(*unkc)++] = arg;
1600                return 1;
1601        }
1602
1603        if ((argcount = parse_long_opt("max-count", argv, &optarg))) {
1604                revs->max_count = atoi(optarg);
1605                revs->no_walk = 0;
1606                return argcount;
1607        } else if ((argcount = parse_long_opt("skip", argv, &optarg))) {
1608                revs->skip_count = atoi(optarg);
1609                return argcount;
1610        } else if ((*arg == '-') && isdigit(arg[1])) {
1611        /* accept -<digit>, like traditional "head" */
1612                revs->max_count = atoi(arg + 1);
1613                revs->no_walk = 0;
1614        } else if (!strcmp(arg, "-n")) {
1615                if (argc <= 1)
1616                        return error("-n requires an argument");
1617                revs->max_count = atoi(argv[1]);
1618                revs->no_walk = 0;
1619                return 2;
1620        } else if (!prefixcmp(arg, "-n")) {
1621                revs->max_count = atoi(arg + 2);
1622                revs->no_walk = 0;
1623        } else if ((argcount = parse_long_opt("max-age", argv, &optarg))) {
1624                revs->max_age = atoi(optarg);
1625                return argcount;
1626        } else if ((argcount = parse_long_opt("since", argv, &optarg))) {
1627                revs->max_age = approxidate(optarg);
1628                return argcount;
1629        } else if ((argcount = parse_long_opt("after", argv, &optarg))) {
1630                revs->max_age = approxidate(optarg);
1631                return argcount;
1632        } else if ((argcount = parse_long_opt("min-age", argv, &optarg))) {
1633                revs->min_age = atoi(optarg);
1634                return argcount;
1635        } else if ((argcount = parse_long_opt("before", argv, &optarg))) {
1636                revs->min_age = approxidate(optarg);
1637                return argcount;
1638        } else if ((argcount = parse_long_opt("until", argv, &optarg))) {
1639                revs->min_age = approxidate(optarg);
1640                return argcount;
1641        } else if (!strcmp(arg, "--first-parent")) {
1642                revs->first_parent_only = 1;
1643        } else if (!strcmp(arg, "--ancestry-path")) {
1644                revs->ancestry_path = 1;
1645                revs->simplify_history = 0;
1646                revs->limited = 1;
1647        } else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
1648                init_reflog_walk(&revs->reflog_info);
1649        } else if (!strcmp(arg, "--default")) {
1650                if (argc <= 1)
1651                        return error("bad --default argument");
1652                revs->def = argv[1];
1653                return 2;
1654        } else if (!strcmp(arg, "--merge")) {
1655                revs->show_merge = 1;
1656        } else if (!strcmp(arg, "--topo-order")) {
1657                revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
1658                revs->topo_order = 1;
1659        } else if (!strcmp(arg, "--simplify-merges")) {
1660                revs->simplify_merges = 1;
1661                revs->topo_order = 1;
1662                revs->rewrite_parents = 1;
1663                revs->simplify_history = 0;
1664                revs->limited = 1;
1665        } else if (!strcmp(arg, "--simplify-by-decoration")) {
1666                revs->simplify_merges = 1;
1667                revs->topo_order = 1;
1668                revs->rewrite_parents = 1;
1669                revs->simplify_history = 0;
1670                revs->simplify_by_decoration = 1;
1671                revs->limited = 1;
1672                revs->prune = 1;
1673                load_ref_decorations(DECORATE_SHORT_REFS);
1674        } else if (!strcmp(arg, "--date-order")) {
1675                revs->sort_order = REV_SORT_BY_COMMIT_DATE;
1676                revs->topo_order = 1;
1677        } else if (!strcmp(arg, "--author-date-order")) {
1678                revs->sort_order = REV_SORT_BY_AUTHOR_DATE;
1679                revs->topo_order = 1;
1680        } else if (!prefixcmp(arg, "--early-output")) {
1681                int count = 100;
1682                switch (arg[14]) {
1683                case '=':
1684                        count = atoi(arg+15);
1685                        /* Fallthrough */
1686                case 0:
1687                        revs->topo_order = 1;
1688                       revs->early_output = count;
1689                }
1690        } else if (!strcmp(arg, "--parents")) {
1691                revs->rewrite_parents = 1;
1692                revs->print_parents = 1;
1693        } else if (!strcmp(arg, "--dense")) {
1694                revs->dense = 1;
1695        } else if (!strcmp(arg, "--sparse")) {
1696                revs->dense = 0;
1697        } else if (!strcmp(arg, "--show-all")) {
1698                revs->show_all = 1;
1699        } else if (!strcmp(arg, "--remove-empty")) {
1700                revs->remove_empty_trees = 1;
1701        } else if (!strcmp(arg, "--merges")) {
1702                revs->min_parents = 2;
1703        } else if (!strcmp(arg, "--no-merges")) {
1704                revs->max_parents = 1;
1705        } else if (!prefixcmp(arg, "--min-parents=")) {
1706                revs->min_parents = atoi(arg+14);
1707        } else if (!prefixcmp(arg, "--no-min-parents")) {
1708                revs->min_parents = 0;
1709        } else if (!prefixcmp(arg, "--max-parents=")) {
1710                revs->max_parents = atoi(arg+14);
1711        } else if (!prefixcmp(arg, "--no-max-parents")) {
1712                revs->max_parents = -1;
1713        } else if (!strcmp(arg, "--boundary")) {
1714                revs->boundary = 1;
1715        } else if (!strcmp(arg, "--left-right")) {
1716                revs->left_right = 1;
1717        } else if (!strcmp(arg, "--left-only")) {
1718                if (revs->right_only)
1719                        die("--left-only is incompatible with --right-only"
1720                            " or --cherry");
1721                revs->left_only = 1;
1722        } else if (!strcmp(arg, "--right-only")) {
1723                if (revs->left_only)
1724                        die("--right-only is incompatible with --left-only");
1725                revs->right_only = 1;
1726        } else if (!strcmp(arg, "--cherry")) {
1727                if (revs->left_only)
1728                        die("--cherry is incompatible with --left-only");
1729                revs->cherry_mark = 1;
1730                revs->right_only = 1;
1731                revs->max_parents = 1;
1732                revs->limited = 1;
1733        } else if (!strcmp(arg, "--count")) {
1734                revs->count = 1;
1735        } else if (!strcmp(arg, "--cherry-mark")) {
1736                if (revs->cherry_pick)
1737                        die("--cherry-mark is incompatible with --cherry-pick");
1738                revs->cherry_mark = 1;
1739                revs->limited = 1; /* needs limit_list() */
1740        } else if (!strcmp(arg, "--cherry-pick")) {
1741                if (revs->cherry_mark)
1742                        die("--cherry-pick is incompatible with --cherry-mark");
1743                revs->cherry_pick = 1;
1744                revs->limited = 1;
1745        } else if (!strcmp(arg, "--objects")) {
1746                revs->tag_objects = 1;
1747                revs->tree_objects = 1;
1748                revs->blob_objects = 1;
1749        } else if (!strcmp(arg, "--objects-edge")) {
1750                revs->tag_objects = 1;
1751                revs->tree_objects = 1;
1752                revs->blob_objects = 1;
1753                revs->edge_hint = 1;
1754        } else if (!strcmp(arg, "--verify-objects")) {
1755                revs->tag_objects = 1;
1756                revs->tree_objects = 1;
1757                revs->blob_objects = 1;
1758                revs->verify_objects = 1;
1759        } else if (!strcmp(arg, "--unpacked")) {
1760                revs->unpacked = 1;
1761        } else if (!prefixcmp(arg, "--unpacked=")) {
1762                die("--unpacked=<packfile> no longer supported.");
1763        } else if (!strcmp(arg, "-r")) {
1764                revs->diff = 1;
1765                DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1766        } else if (!strcmp(arg, "-t")) {
1767                revs->diff = 1;
1768                DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
1769                DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
1770        } else if (!strcmp(arg, "-m")) {
1771                revs->ignore_merges = 0;
1772        } else if (!strcmp(arg, "-c")) {
1773                revs->diff = 1;
1774                revs->dense_combined_merges = 0;
1775                revs->combine_merges = 1;
1776        } else if (!strcmp(arg, "--cc")) {
1777                revs->diff = 1;
1778                revs->dense_combined_merges = 1;
1779                revs->combine_merges = 1;
1780        } else if (!strcmp(arg, "-v")) {
1781                revs->verbose_header = 1;
1782        } else if (!strcmp(arg, "--pretty")) {
1783                revs->verbose_header = 1;
1784                revs->pretty_given = 1;
1785                get_commit_format(arg+8, revs);
1786        } else if (!prefixcmp(arg, "--pretty=") || !prefixcmp(arg, "--format=")) {
1787                /*
1788                 * Detached form ("--pretty X" as opposed to "--pretty=X")
1789                 * not allowed, since the argument is optional.
1790                 */
1791                revs->verbose_header = 1;
1792                revs->pretty_given = 1;
1793                get_commit_format(arg+9, revs);
1794        } else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
1795                revs->show_notes = 1;
1796                revs->show_notes_given = 1;
1797                revs->notes_opt.use_default_notes = 1;
1798        } else if (!strcmp(arg, "--show-signature")) {
1799                revs->show_signature = 1;
1800        } else if (!prefixcmp(arg, "--show-notes=") ||
1801                   !prefixcmp(arg, "--notes=")) {
1802                struct strbuf buf = STRBUF_INIT;
1803                revs->show_notes = 1;
1804                revs->show_notes_given = 1;
1805                if (!prefixcmp(arg, "--show-notes")) {
1806                        if (revs->notes_opt.use_default_notes < 0)
1807                                revs->notes_opt.use_default_notes = 1;
1808                        strbuf_addstr(&buf, arg+13);
1809                }
1810                else
1811                        strbuf_addstr(&buf, arg+8);
1812                expand_notes_ref(&buf);
1813                string_list_append(&revs->notes_opt.extra_notes_refs,
1814                                   strbuf_detach(&buf, NULL));
1815        } else if (!strcmp(arg, "--no-notes")) {
1816                revs->show_notes = 0;
1817                revs->show_notes_given = 1;
1818                revs->notes_opt.use_default_notes = -1;
1819                /* we have been strdup'ing ourselves, so trick
1820                 * string_list into free()ing strings */
1821                revs->notes_opt.extra_notes_refs.strdup_strings = 1;
1822                string_list_clear(&revs->notes_opt.extra_notes_refs, 0);
1823                revs->notes_opt.extra_notes_refs.strdup_strings = 0;
1824        } else if (!strcmp(arg, "--standard-notes")) {
1825                revs->show_notes_given = 1;
1826                revs->notes_opt.use_default_notes = 1;
1827        } else if (!strcmp(arg, "--no-standard-notes")) {
1828                revs->notes_opt.use_default_notes = 0;
1829        } else if (!strcmp(arg, "--oneline")) {
1830                revs->verbose_header = 1;
1831                get_commit_format("oneline", revs);
1832                revs->pretty_given = 1;
1833                revs->abbrev_commit = 1;
1834        } else if (!strcmp(arg, "--graph")) {
1835                revs->topo_order = 1;
1836                revs->rewrite_parents = 1;
1837                revs->graph = graph_init(revs);
1838        } else if (!strcmp(arg, "--root")) {
1839                revs->show_root_diff = 1;
1840        } else if (!strcmp(arg, "--no-commit-id")) {
1841                revs->no_commit_id = 1;
1842        } else if (!strcmp(arg, "--always")) {
1843                revs->always_show_header = 1;
1844        } else if (!strcmp(arg, "--no-abbrev")) {
1845                revs->abbrev = 0;
1846        } else if (!strcmp(arg, "--abbrev")) {
1847                revs->abbrev = DEFAULT_ABBREV;
1848        } else if (!prefixcmp(arg, "--abbrev=")) {
1849                revs->abbrev = strtoul(arg + 9, NULL, 10);
1850                if (revs->abbrev < MINIMUM_ABBREV)
1851                        revs->abbrev = MINIMUM_ABBREV;
1852                else if (revs->abbrev > 40)
1853                        revs->abbrev = 40;
1854        } else if (!strcmp(arg, "--abbrev-commit")) {
1855                revs->abbrev_commit = 1;
1856                revs->abbrev_commit_given = 1;
1857        } else if (!strcmp(arg, "--no-abbrev-commit")) {
1858                revs->abbrev_commit = 0;
1859        } else if (!strcmp(arg, "--full-diff")) {
1860                revs->diff = 1;
1861                revs->full_diff = 1;
1862        } else if (!strcmp(arg, "--full-history")) {
1863                revs->simplify_history = 0;
1864        } else if (!strcmp(arg, "--relative-date")) {
1865                revs->date_mode = DATE_RELATIVE;
1866                revs->date_mode_explicit = 1;
1867        } else if ((argcount = parse_long_opt("date", argv, &optarg))) {
1868                revs->date_mode = parse_date_format(optarg);
1869                revs->date_mode_explicit = 1;
1870                return argcount;
1871        } else if (!strcmp(arg, "--log-size")) {
1872                revs->show_log_size = 1;
1873        }
1874        /*
1875         * Grepping the commit log
1876         */
1877        else if ((argcount = parse_long_opt("author", argv, &optarg))) {
1878                add_header_grep(revs, GREP_HEADER_AUTHOR, optarg);
1879                return argcount;
1880        } else if ((argcount = parse_long_opt("committer", argv, &optarg))) {
1881                add_header_grep(revs, GREP_HEADER_COMMITTER, optarg);
1882                return argcount;
1883        } else if ((argcount = parse_long_opt("grep-reflog", argv, &optarg))) {
1884                add_header_grep(revs, GREP_HEADER_REFLOG, optarg);
1885                return argcount;
1886        } else if ((argcount = parse_long_opt("grep", argv, &optarg))) {
1887                add_message_grep(revs, optarg);
1888                return argcount;
1889        } else if (!strcmp(arg, "--grep-debug")) {
1890                revs->grep_filter.debug = 1;
1891        } else if (!strcmp(arg, "--basic-regexp")) {
1892                grep_set_pattern_type_option(GREP_PATTERN_TYPE_BRE, &revs->grep_filter);
1893        } else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
1894                grep_set_pattern_type_option(GREP_PATTERN_TYPE_ERE, &revs->grep_filter);
1895        } else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
1896                revs->grep_filter.regflags |= REG_ICASE;
1897                DIFF_OPT_SET(&revs->diffopt, PICKAXE_IGNORE_CASE);
1898        } else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
1899                grep_set_pattern_type_option(GREP_PATTERN_TYPE_FIXED, &revs->grep_filter);
1900        } else if (!strcmp(arg, "--perl-regexp")) {
1901                grep_set_pattern_type_option(GREP_PATTERN_TYPE_PCRE, &revs->grep_filter);
1902        } else if (!strcmp(arg, "--all-match")) {
1903                revs->grep_filter.all_match = 1;
1904        } else if ((argcount = parse_long_opt("encoding", argv, &optarg))) {
1905                if (strcmp(optarg, "none"))
1906                        git_log_output_encoding = xstrdup(optarg);
1907                else
1908                        git_log_output_encoding = "";
1909                return argcount;
1910        } else if (!strcmp(arg, "--reverse")) {
1911                revs->reverse ^= 1;
1912        } else if (!strcmp(arg, "--children")) {
1913                revs->children.name = "children";
1914                revs->limited = 1;
1915        } else if (!strcmp(arg, "--ignore-missing")) {
1916                revs->ignore_missing = 1;
1917        } else {
1918                int opts = diff_opt_parse(&revs->diffopt, argv, argc);
1919                if (!opts)
1920                        unkv[(*unkc)++] = arg;
1921                return opts;
1922        }
1923
1924        return 1;
1925}
1926
1927void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
1928                        const struct option *options,
1929                        const char * const usagestr[])
1930{
1931        int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
1932                                    &ctx->cpidx, ctx->out);
1933        if (n <= 0) {
1934                error("unknown option `%s'", ctx->argv[0]);
1935                usage_with_options(usagestr, options);
1936        }
1937        ctx->argv += n;
1938        ctx->argc -= n;
1939}
1940
1941static int for_each_bad_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1942{
1943        return for_each_ref_in_submodule(submodule, "refs/bisect/bad", fn, cb_data);
1944}
1945
1946static int for_each_good_bisect_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1947{
1948        return for_each_ref_in_submodule(submodule, "refs/bisect/good", fn, cb_data);
1949}
1950
1951static int handle_revision_pseudo_opt(const char *submodule,
1952                                struct rev_info *revs,
1953                                int argc, const char **argv, int *flags)
1954{
1955        const char *arg = argv[0];
1956        const char *optarg;
1957        int argcount;
1958
1959        /*
1960         * NOTE!
1961         *
1962         * Commands like "git shortlog" will not accept the options below
1963         * unless parse_revision_opt queues them (as opposed to erroring
1964         * out).
1965         *
1966         * When implementing your new pseudo-option, remember to
1967         * register it in the list at the top of handle_revision_opt.
1968         */
1969        if (!strcmp(arg, "--all")) {
1970                handle_refs(submodule, revs, *flags, for_each_ref_submodule);
1971                handle_refs(submodule, revs, *flags, head_ref_submodule);
1972        } else if (!strcmp(arg, "--branches")) {
1973                handle_refs(submodule, revs, *flags, for_each_branch_ref_submodule);
1974        } else if (!strcmp(arg, "--bisect")) {
1975                handle_refs(submodule, revs, *flags, for_each_bad_bisect_ref);
1976                handle_refs(submodule, revs, *flags ^ (UNINTERESTING | BOTTOM), for_each_good_bisect_ref);
1977                revs->bisect = 1;
1978        } else if (!strcmp(arg, "--tags")) {
1979                handle_refs(submodule, revs, *flags, for_each_tag_ref_submodule);
1980        } else if (!strcmp(arg, "--remotes")) {
1981                handle_refs(submodule, revs, *flags, for_each_remote_ref_submodule);
1982        } else if ((argcount = parse_long_opt("glob", argv, &optarg))) {
1983                struct all_refs_cb cb;
1984                init_all_refs_cb(&cb, revs, *flags);
1985                for_each_glob_ref(handle_one_ref, optarg, &cb);
1986                return argcount;
1987        } else if (!prefixcmp(arg, "--branches=")) {
1988                struct all_refs_cb cb;
1989                init_all_refs_cb(&cb, revs, *flags);
1990                for_each_glob_ref_in(handle_one_ref, arg + 11, "refs/heads/", &cb);
1991        } else if (!prefixcmp(arg, "--tags=")) {
1992                struct all_refs_cb cb;
1993                init_all_refs_cb(&cb, revs, *flags);
1994                for_each_glob_ref_in(handle_one_ref, arg + 7, "refs/tags/", &cb);
1995        } else if (!prefixcmp(arg, "--remotes=")) {
1996                struct all_refs_cb cb;
1997                init_all_refs_cb(&cb, revs, *flags);
1998                for_each_glob_ref_in(handle_one_ref, arg + 10, "refs/remotes/", &cb);
1999        } else if (!strcmp(arg, "--reflog")) {
2000                handle_reflog(revs, *flags);
2001        } else if (!strcmp(arg, "--not")) {
2002                *flags ^= UNINTERESTING | BOTTOM;
2003        } else if (!strcmp(arg, "--no-walk")) {
2004                revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
2005        } else if (!prefixcmp(arg, "--no-walk=")) {
2006                /*
2007                 * Detached form ("--no-walk X" as opposed to "--no-walk=X")
2008                 * not allowed, since the argument is optional.
2009                 */
2010                if (!strcmp(arg + 10, "sorted"))
2011                        revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
2012                else if (!strcmp(arg + 10, "unsorted"))
2013                        revs->no_walk = REVISION_WALK_NO_WALK_UNSORTED;
2014                else
2015                        return error("invalid argument to --no-walk");
2016        } else if (!strcmp(arg, "--do-walk")) {
2017                revs->no_walk = 0;
2018        } else {
2019                return 0;
2020        }
2021
2022        return 1;
2023}
2024
2025/*
2026 * Parse revision information, filling in the "rev_info" structure,
2027 * and removing the used arguments from the argument list.
2028 *
2029 * Returns the number of arguments left that weren't recognized
2030 * (which are also moved to the head of the argument list)
2031 */
2032int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
2033{
2034        int i, flags, left, seen_dashdash, read_from_stdin, got_rev_arg = 0, revarg_opt;
2035        struct cmdline_pathspec prune_data;
2036        const char *submodule = NULL;
2037
2038        memset(&prune_data, 0, sizeof(prune_data));
2039        if (opt)
2040                submodule = opt->submodule;
2041
2042        /* First, search for "--" */
2043        if (opt && opt->assume_dashdash) {
2044                seen_dashdash = 1;
2045        } else {
2046                seen_dashdash = 0;
2047                for (i = 1; i < argc; i++) {
2048                        const char *arg = argv[i];
2049                        if (strcmp(arg, "--"))
2050                                continue;
2051                        argv[i] = NULL;
2052                        argc = i;
2053                        if (argv[i + 1])
2054                                append_prune_data(&prune_data, argv + i + 1);
2055                        seen_dashdash = 1;
2056                        break;
2057                }
2058        }
2059
2060        /* Second, deal with arguments and options */
2061        flags = 0;
2062        revarg_opt = opt ? opt->revarg_opt : 0;
2063        if (seen_dashdash)
2064                revarg_opt |= REVARG_CANNOT_BE_FILENAME;
2065        read_from_stdin = 0;
2066        for (left = i = 1; i < argc; i++) {
2067                const char *arg = argv[i];
2068                if (*arg == '-') {
2069                        int opts;
2070
2071                        opts = handle_revision_pseudo_opt(submodule,
2072                                                revs, argc - i, argv + i,
2073                                                &flags);
2074                        if (opts > 0) {
2075                                i += opts - 1;
2076                                continue;
2077                        }
2078
2079                        if (!strcmp(arg, "--stdin")) {
2080                                if (revs->disable_stdin) {
2081                                        argv[left++] = arg;
2082                                        continue;
2083                                }
2084                                if (read_from_stdin++)
2085                                        die("--stdin given twice?");
2086                                read_revisions_from_stdin(revs, &prune_data);
2087                                continue;
2088                        }
2089
2090                        opts = handle_revision_opt(revs, argc - i, argv + i, &left, argv);
2091                        if (opts > 0) {
2092                                i += opts - 1;
2093                                continue;
2094                        }
2095                        if (opts < 0)
2096                                exit(128);
2097                        continue;
2098                }
2099
2100
2101                if (handle_revision_arg(arg, revs, flags, revarg_opt)) {
2102                        int j;
2103                        if (seen_dashdash || *arg == '^')
2104                                die("bad revision '%s'", arg);
2105
2106                        /* If we didn't have a "--":
2107                         * (1) all filenames must exist;
2108                         * (2) all rev-args must not be interpretable
2109                         *     as a valid filename.
2110                         * but the latter we have checked in the main loop.
2111                         */
2112                        for (j = i; j < argc; j++)
2113                                verify_filename(revs->prefix, argv[j], j == i);
2114
2115                        append_prune_data(&prune_data, argv + i);
2116                        break;
2117                }
2118                else
2119                        got_rev_arg = 1;
2120        }
2121
2122        if (prune_data.nr) {
2123                /*
2124                 * If we need to introduce the magic "a lone ':' means no
2125                 * pathspec whatsoever", here is the place to do so.
2126                 *
2127                 * if (prune_data.nr == 1 && !strcmp(prune_data[0], ":")) {
2128                 *      prune_data.nr = 0;
2129                 *      prune_data.alloc = 0;
2130                 *      free(prune_data.path);
2131                 *      prune_data.path = NULL;
2132                 * } else {
2133                 *      terminate prune_data.alloc with NULL and
2134                 *      call init_pathspec() to set revs->prune_data here.
2135                 * }
2136                 */
2137                ALLOC_GROW(prune_data.path, prune_data.nr+1, prune_data.alloc);
2138                prune_data.path[prune_data.nr++] = NULL;
2139                parse_pathspec(&revs->prune_data, 0, 0,
2140                               revs->prefix, prune_data.path);
2141        }
2142
2143        if (revs->def == NULL)
2144                revs->def = opt ? opt->def : NULL;
2145        if (opt && opt->tweak)
2146                opt->tweak(revs, opt);
2147        if (revs->show_merge)
2148                prepare_show_merge(revs);
2149        if (revs->def && !revs->pending.nr && !got_rev_arg) {
2150                unsigned char sha1[20];
2151                struct object *object;
2152                struct object_context oc;
2153                if (get_sha1_with_context(revs->def, 0, sha1, &oc))
2154                        die("bad default revision '%s'", revs->def);
2155                object = get_reference(revs, revs->def, sha1, 0);
2156                add_pending_object_with_mode(revs, object, revs->def, oc.mode);
2157        }
2158
2159        /* Did the user ask for any diff output? Run the diff! */
2160        if (revs->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT)
2161                revs->diff = 1;
2162
2163        /* Pickaxe, diff-filter and rename following need diffs */
2164        if (revs->diffopt.pickaxe ||
2165            revs->diffopt.filter ||
2166            DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
2167                revs->diff = 1;
2168
2169        if (revs->topo_order)
2170                revs->limited = 1;
2171
2172        if (revs->prune_data.nr) {
2173                copy_pathspec(&revs->pruning.pathspec, &revs->prune_data);
2174                /* Can't prune commits with rename following: the paths change.. */
2175                if (!DIFF_OPT_TST(&revs->diffopt, FOLLOW_RENAMES))
2176                        revs->prune = 1;
2177                if (!revs->full_diff)
2178                        copy_pathspec(&revs->diffopt.pathspec,
2179                                      &revs->prune_data);
2180        }
2181        if (revs->combine_merges)
2182                revs->ignore_merges = 0;
2183        revs->diffopt.abbrev = revs->abbrev;
2184
2185        if (revs->line_level_traverse) {
2186                revs->limited = 1;
2187                revs->topo_order = 1;
2188        }
2189
2190        diff_setup_done(&revs->diffopt);
2191
2192        grep_commit_pattern_type(GREP_PATTERN_TYPE_UNSPECIFIED,
2193                                 &revs->grep_filter);
2194        compile_grep_patterns(&revs->grep_filter);
2195
2196        if (revs->reverse && revs->reflog_info)
2197                die("cannot combine --reverse with --walk-reflogs");
2198        if (revs->rewrite_parents && revs->children.name)
2199                die("cannot combine --parents and --children");
2200
2201        /*
2202         * Limitations on the graph functionality
2203         */
2204        if (revs->reverse && revs->graph)
2205                die("cannot combine --reverse with --graph");
2206
2207        if (revs->reflog_info && revs->graph)
2208                die("cannot combine --walk-reflogs with --graph");
2209        if (!revs->reflog_info && revs->grep_filter.use_reflog_filter)
2210                die("cannot use --grep-reflog without --walk-reflogs");
2211
2212        return left;
2213}
2214
2215static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
2216{
2217        struct commit_list *l = xcalloc(1, sizeof(*l));
2218
2219        l->item = child;
2220        l->next = add_decoration(&revs->children, &parent->object, l);
2221}
2222
2223static int remove_duplicate_parents(struct rev_info *revs, struct commit *commit)
2224{
2225        struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2226        struct commit_list **pp, *p;
2227        int surviving_parents;
2228
2229        /* Examine existing parents while marking ones we have seen... */
2230        pp = &commit->parents;
2231        surviving_parents = 0;
2232        while ((p = *pp) != NULL) {
2233                struct commit *parent = p->item;
2234                if (parent->object.flags & TMP_MARK) {
2235                        *pp = p->next;
2236                        if (ts)
2237                                compact_treesame(revs, commit, surviving_parents);
2238                        continue;
2239                }
2240                parent->object.flags |= TMP_MARK;
2241                surviving_parents++;
2242                pp = &p->next;
2243        }
2244        /* clear the temporary mark */
2245        for (p = commit->parents; p; p = p->next) {
2246                p->item->object.flags &= ~TMP_MARK;
2247        }
2248        /* no update_treesame() - removing duplicates can't affect TREESAME */
2249        return surviving_parents;
2250}
2251
2252struct merge_simplify_state {
2253        struct commit *simplified;
2254};
2255
2256static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
2257{
2258        struct merge_simplify_state *st;
2259
2260        st = lookup_decoration(&revs->merge_simplification, &commit->object);
2261        if (!st) {
2262                st = xcalloc(1, sizeof(*st));
2263                add_decoration(&revs->merge_simplification, &commit->object, st);
2264        }
2265        return st;
2266}
2267
2268static int mark_redundant_parents(struct rev_info *revs, struct commit *commit)
2269{
2270        struct commit_list *h = reduce_heads(commit->parents);
2271        int i = 0, marked = 0;
2272        struct commit_list *po, *pn;
2273
2274        /* Want these for sanity-checking only */
2275        int orig_cnt = commit_list_count(commit->parents);
2276        int cnt = commit_list_count(h);
2277
2278        /*
2279         * Not ready to remove items yet, just mark them for now, based
2280         * on the output of reduce_heads(). reduce_heads outputs the reduced
2281         * set in its original order, so this isn't too hard.
2282         */
2283        po = commit->parents;
2284        pn = h;
2285        while (po) {
2286                if (pn && po->item == pn->item) {
2287                        pn = pn->next;
2288                        i++;
2289                } else {
2290                        po->item->object.flags |= TMP_MARK;
2291                        marked++;
2292                }
2293                po=po->next;
2294        }
2295
2296        if (i != cnt || cnt+marked != orig_cnt)
2297                die("mark_redundant_parents %d %d %d %d", orig_cnt, cnt, i, marked);
2298
2299        free_commit_list(h);
2300
2301        return marked;
2302}
2303
2304static int mark_treesame_root_parents(struct rev_info *revs, struct commit *commit)
2305{
2306        struct commit_list *p;
2307        int marked = 0;
2308
2309        for (p = commit->parents; p; p = p->next) {
2310                struct commit *parent = p->item;
2311                if (!parent->parents && (parent->object.flags & TREESAME)) {
2312                        parent->object.flags |= TMP_MARK;
2313                        marked++;
2314                }
2315        }
2316
2317        return marked;
2318}
2319
2320/*
2321 * Awkward naming - this means one parent we are TREESAME to.
2322 * cf mark_treesame_root_parents: root parents that are TREESAME (to an
2323 * empty tree). Better name suggestions?
2324 */
2325static int leave_one_treesame_to_parent(struct rev_info *revs, struct commit *commit)
2326{
2327        struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2328        struct commit *unmarked = NULL, *marked = NULL;
2329        struct commit_list *p;
2330        unsigned n;
2331
2332        for (p = commit->parents, n = 0; p; p = p->next, n++) {
2333                if (ts->treesame[n]) {
2334                        if (p->item->object.flags & TMP_MARK) {
2335                                if (!marked)
2336                                        marked = p->item;
2337                        } else {
2338                                if (!unmarked) {
2339                                        unmarked = p->item;
2340                                        break;
2341                                }
2342                        }
2343                }
2344        }
2345
2346        /*
2347         * If we are TREESAME to a marked-for-deletion parent, but not to any
2348         * unmarked parents, unmark the first TREESAME parent. This is the
2349         * parent that the default simplify_history==1 scan would have followed,
2350         * and it doesn't make sense to omit that path when asking for a
2351         * simplified full history. Retaining it improves the chances of
2352         * understanding odd missed merges that took an old version of a file.
2353         *
2354         * Example:
2355         *
2356         *   I--------*X       A modified the file, but mainline merge X used
2357         *    \       /        "-s ours", so took the version from I. X is
2358         *     `-*A--'         TREESAME to I and !TREESAME to A.
2359         *
2360         * Default log from X would produce "I". Without this check,
2361         * --full-history --simplify-merges would produce "I-A-X", showing
2362         * the merge commit X and that it changed A, but not making clear that
2363         * it had just taken the I version. With this check, the topology above
2364         * is retained.
2365         *
2366         * Note that it is possible that the simplification chooses a different
2367         * TREESAME parent from the default, in which case this test doesn't
2368         * activate, and we _do_ drop the default parent. Example:
2369         *
2370         *   I------X         A modified the file, but it was reverted in B,
2371         *    \    /          meaning mainline merge X is TREESAME to both
2372         *    *A-*B           parents.
2373         *
2374         * Default log would produce "I" by following the first parent;
2375         * --full-history --simplify-merges will produce "I-A-B". But this is a
2376         * reasonable result - it presents a logical full history leading from
2377         * I to X, and X is not an important merge.
2378         */
2379        if (!unmarked && marked) {
2380                marked->object.flags &= ~TMP_MARK;
2381                return 1;
2382        }
2383
2384        return 0;
2385}
2386
2387static int remove_marked_parents(struct rev_info *revs, struct commit *commit)
2388{
2389        struct commit_list **pp, *p;
2390        int nth_parent, removed = 0;
2391
2392        pp = &commit->parents;
2393        nth_parent = 0;
2394        while ((p = *pp) != NULL) {
2395                struct commit *parent = p->item;
2396                if (parent->object.flags & TMP_MARK) {
2397                        parent->object.flags &= ~TMP_MARK;
2398                        *pp = p->next;
2399                        free(p);
2400                        removed++;
2401                        compact_treesame(revs, commit, nth_parent);
2402                        continue;
2403                }
2404                pp = &p->next;
2405                nth_parent++;
2406        }
2407
2408        /* Removing parents can only increase TREESAMEness */
2409        if (removed && !(commit->object.flags & TREESAME))
2410                update_treesame(revs, commit);
2411
2412        return nth_parent;
2413}
2414
2415static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
2416{
2417        struct commit_list *p;
2418        struct commit *parent;
2419        struct merge_simplify_state *st, *pst;
2420        int cnt;
2421
2422        st = locate_simplify_state(revs, commit);
2423
2424        /*
2425         * Have we handled this one?
2426         */
2427        if (st->simplified)
2428                return tail;
2429
2430        /*
2431         * An UNINTERESTING commit simplifies to itself, so does a
2432         * root commit.  We do not rewrite parents of such commit
2433         * anyway.
2434         */
2435        if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
2436                st->simplified = commit;
2437                return tail;
2438        }
2439
2440        /*
2441         * Do we know what commit all of our parents that matter
2442         * should be rewritten to?  Otherwise we are not ready to
2443         * rewrite this one yet.
2444         */
2445        for (cnt = 0, p = commit->parents; p; p = p->next) {
2446                pst = locate_simplify_state(revs, p->item);
2447                if (!pst->simplified) {
2448                        tail = &commit_list_insert(p->item, tail)->next;
2449                        cnt++;
2450                }
2451                if (revs->first_parent_only)
2452                        break;
2453        }
2454        if (cnt) {
2455                tail = &commit_list_insert(commit, tail)->next;
2456                return tail;
2457        }
2458
2459        /*
2460         * Rewrite our list of parents. Note that this cannot
2461         * affect our TREESAME flags in any way - a commit is
2462         * always TREESAME to its simplification.
2463         */
2464        for (p = commit->parents; p; p = p->next) {
2465                pst = locate_simplify_state(revs, p->item);
2466                p->item = pst->simplified;
2467                if (revs->first_parent_only)
2468                        break;
2469        }
2470
2471        if (revs->first_parent_only)
2472                cnt = 1;
2473        else
2474                cnt = remove_duplicate_parents(revs, commit);
2475
2476        /*
2477         * It is possible that we are a merge and one side branch
2478         * does not have any commit that touches the given paths;
2479         * in such a case, the immediate parent from that branch
2480         * will be rewritten to be the merge base.
2481         *
2482         *      o----X          X: the commit we are looking at;
2483         *     /    /           o: a commit that touches the paths;
2484         * ---o----'
2485         *
2486         * Further, a merge of an independent branch that doesn't
2487         * touch the path will reduce to a treesame root parent:
2488         *
2489         *  ----o----X          X: the commit we are looking at;
2490         *          /           o: a commit that touches the paths;
2491         *         r            r: a root commit not touching the paths
2492         *
2493         * Detect and simplify both cases.
2494         */
2495        if (1 < cnt) {
2496                int marked = mark_redundant_parents(revs, commit);
2497                marked += mark_treesame_root_parents(revs, commit);
2498                if (marked)
2499                        marked -= leave_one_treesame_to_parent(revs, commit);
2500                if (marked)
2501                        cnt = remove_marked_parents(revs, commit);
2502        }
2503
2504        /*
2505         * A commit simplifies to itself if it is a root, if it is
2506         * UNINTERESTING, if it touches the given paths, or if it is a
2507         * merge and its parents don't simplify to one relevant commit
2508         * (the first two cases are already handled at the beginning of
2509         * this function).
2510         *
2511         * Otherwise, it simplifies to what its sole relevant parent
2512         * simplifies to.
2513         */
2514        if (!cnt ||
2515            (commit->object.flags & UNINTERESTING) ||
2516            !(commit->object.flags & TREESAME) ||
2517            (parent = one_relevant_parent(revs, commit->parents)) == NULL)
2518                st->simplified = commit;
2519        else {
2520                pst = locate_simplify_state(revs, parent);
2521                st->simplified = pst->simplified;
2522        }
2523        return tail;
2524}
2525
2526static void simplify_merges(struct rev_info *revs)
2527{
2528        struct commit_list *list, *next;
2529        struct commit_list *yet_to_do, **tail;
2530        struct commit *commit;
2531
2532        if (!revs->prune)
2533                return;
2534
2535        /* feed the list reversed */
2536        yet_to_do = NULL;
2537        for (list = revs->commits; list; list = next) {
2538                commit = list->item;
2539                next = list->next;
2540                /*
2541                 * Do not free(list) here yet; the original list
2542                 * is used later in this function.
2543                 */
2544                commit_list_insert(commit, &yet_to_do);
2545        }
2546        while (yet_to_do) {
2547                list = yet_to_do;
2548                yet_to_do = NULL;
2549                tail = &yet_to_do;
2550                while (list) {
2551                        commit = list->item;
2552                        next = list->next;
2553                        free(list);
2554                        list = next;
2555                        tail = simplify_one(revs, commit, tail);
2556                }
2557        }
2558
2559        /* clean up the result, removing the simplified ones */
2560        list = revs->commits;
2561        revs->commits = NULL;
2562        tail = &revs->commits;
2563        while (list) {
2564                struct merge_simplify_state *st;
2565
2566                commit = list->item;
2567                next = list->next;
2568                free(list);
2569                list = next;
2570                st = locate_simplify_state(revs, commit);
2571                if (st->simplified == commit)
2572                        tail = &commit_list_insert(commit, tail)->next;
2573        }
2574}
2575
2576static void set_children(struct rev_info *revs)
2577{
2578        struct commit_list *l;
2579        for (l = revs->commits; l; l = l->next) {
2580                struct commit *commit = l->item;
2581                struct commit_list *p;
2582
2583                for (p = commit->parents; p; p = p->next)
2584                        add_child(revs, p->item, commit);
2585        }
2586}
2587
2588void reset_revision_walk(void)
2589{
2590        clear_object_flags(SEEN | ADDED | SHOWN);
2591}
2592
2593int prepare_revision_walk(struct rev_info *revs)
2594{
2595        int nr = revs->pending.nr;
2596        struct object_array_entry *e, *list;
2597        struct commit_list **next = &revs->commits;
2598
2599        e = list = revs->pending.objects;
2600        revs->pending.nr = 0;
2601        revs->pending.alloc = 0;
2602        revs->pending.objects = NULL;
2603        while (--nr >= 0) {
2604                struct commit *commit = handle_commit(revs, e->item, e->name);
2605                if (commit) {
2606                        if (!(commit->object.flags & SEEN)) {
2607                                commit->object.flags |= SEEN;
2608                                next = commit_list_append(commit, next);
2609                        }
2610                }
2611                e++;
2612        }
2613        if (!revs->leak_pending)
2614                free(list);
2615
2616        /* Signal whether we need per-parent treesame decoration */
2617        if (revs->simplify_merges ||
2618            (revs->limited && limiting_can_increase_treesame(revs)))
2619                revs->treesame.name = "treesame";
2620
2621        if (revs->no_walk != REVISION_WALK_NO_WALK_UNSORTED)
2622                commit_list_sort_by_date(&revs->commits);
2623        if (revs->no_walk)
2624                return 0;
2625        if (revs->limited)
2626                if (limit_list(revs) < 0)
2627                        return -1;
2628        if (revs->topo_order)
2629                sort_in_topological_order(&revs->commits, revs->sort_order);
2630        if (revs->line_level_traverse)
2631                line_log_filter(revs);
2632        if (revs->simplify_merges)
2633                simplify_merges(revs);
2634        if (revs->children.name)
2635                set_children(revs);
2636        return 0;
2637}
2638
2639static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
2640{
2641        struct commit_list *cache = NULL;
2642
2643        for (;;) {
2644                struct commit *p = *pp;
2645                if (!revs->limited)
2646                        if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0)
2647                                return rewrite_one_error;
2648                if (p->object.flags & UNINTERESTING)
2649                        return rewrite_one_ok;
2650                if (!(p->object.flags & TREESAME))
2651                        return rewrite_one_ok;
2652                if (!p->parents)
2653                        return rewrite_one_noparents;
2654                if ((p = one_relevant_parent(revs, p->parents)) == NULL)
2655                        return rewrite_one_ok;
2656                *pp = p;
2657        }
2658}
2659
2660int rewrite_parents(struct rev_info *revs, struct commit *commit,
2661        rewrite_parent_fn_t rewrite_parent)
2662{
2663        struct commit_list **pp = &commit->parents;
2664        while (*pp) {
2665                struct commit_list *parent = *pp;
2666                switch (rewrite_parent(revs, &parent->item)) {
2667                case rewrite_one_ok:
2668                        break;
2669                case rewrite_one_noparents:
2670                        *pp = parent->next;
2671                        continue;
2672                case rewrite_one_error:
2673                        return -1;
2674                }
2675                pp = &parent->next;
2676        }
2677        remove_duplicate_parents(revs, commit);
2678        return 0;
2679}
2680
2681static int commit_rewrite_person(struct strbuf *buf, const char *what, struct string_list *mailmap)
2682{
2683        char *person, *endp;
2684        size_t len, namelen, maillen;
2685        const char *name;
2686        const char *mail;
2687        struct ident_split ident;
2688
2689        person = strstr(buf->buf, what);
2690        if (!person)
2691                return 0;
2692
2693        person += strlen(what);
2694        endp = strchr(person, '\n');
2695        if (!endp)
2696                return 0;
2697
2698        len = endp - person;
2699
2700        if (split_ident_line(&ident, person, len))
2701                return 0;
2702
2703        mail = ident.mail_begin;
2704        maillen = ident.mail_end - ident.mail_begin;
2705        name = ident.name_begin;
2706        namelen = ident.name_end - ident.name_begin;
2707
2708        if (map_user(mailmap, &mail, &maillen, &name, &namelen)) {
2709                struct strbuf namemail = STRBUF_INIT;
2710
2711                strbuf_addf(&namemail, "%.*s <%.*s>",
2712                            (int)namelen, name, (int)maillen, mail);
2713
2714                strbuf_splice(buf, ident.name_begin - buf->buf,
2715                              ident.mail_end - ident.name_begin + 1,
2716                              namemail.buf, namemail.len);
2717
2718                strbuf_release(&namemail);
2719
2720                return 1;
2721        }
2722
2723        return 0;
2724}
2725
2726static int commit_match(struct commit *commit, struct rev_info *opt)
2727{
2728        int retval;
2729        const char *encoding;
2730        char *message;
2731        struct strbuf buf = STRBUF_INIT;
2732
2733        if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
2734                return 1;
2735
2736        /* Prepend "fake" headers as needed */
2737        if (opt->grep_filter.use_reflog_filter) {
2738                strbuf_addstr(&buf, "reflog ");
2739                get_reflog_message(&buf, opt->reflog_info);
2740                strbuf_addch(&buf, '\n');
2741        }
2742
2743        /*
2744         * We grep in the user's output encoding, under the assumption that it
2745         * is the encoding they are most likely to write their grep pattern
2746         * for. In addition, it means we will match the "notes" encoding below,
2747         * so we will not end up with a buffer that has two different encodings
2748         * in it.
2749         */
2750        encoding = get_log_output_encoding();
2751        message = logmsg_reencode(commit, NULL, encoding);
2752
2753        /* Copy the commit to temporary if we are using "fake" headers */
2754        if (buf.len)
2755                strbuf_addstr(&buf, message);
2756
2757        if (opt->grep_filter.header_list && opt->mailmap) {
2758                if (!buf.len)
2759                        strbuf_addstr(&buf, message);
2760
2761                commit_rewrite_person(&buf, "\nauthor ", opt->mailmap);
2762                commit_rewrite_person(&buf, "\ncommitter ", opt->mailmap);
2763        }
2764
2765        /* Append "fake" message parts as needed */
2766        if (opt->show_notes) {
2767                if (!buf.len)
2768                        strbuf_addstr(&buf, message);
2769                format_display_notes(commit->object.sha1, &buf, encoding, 1);
2770        }
2771
2772        /* Find either in the original commit message, or in the temporary */
2773        if (buf.len)
2774                retval = grep_buffer(&opt->grep_filter, buf.buf, buf.len);
2775        else
2776                retval = grep_buffer(&opt->grep_filter,
2777                                     message, strlen(message));
2778        strbuf_release(&buf);
2779        logmsg_free(message, commit);
2780        return retval;
2781}
2782
2783static inline int want_ancestry(const struct rev_info *revs)
2784{
2785        return (revs->rewrite_parents || revs->children.name);
2786}
2787
2788enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
2789{
2790        if (commit->object.flags & SHOWN)
2791                return commit_ignore;
2792        if (revs->unpacked && has_sha1_pack(commit->object.sha1))
2793                return commit_ignore;
2794        if (revs->show_all)
2795                return commit_show;
2796        if (commit->object.flags & UNINTERESTING)
2797                return commit_ignore;
2798        if (revs->min_age != -1 && (commit->date > revs->min_age))
2799                return commit_ignore;
2800        if (revs->min_parents || (revs->max_parents >= 0)) {
2801                int n = commit_list_count(commit->parents);
2802                if ((n < revs->min_parents) ||
2803                    ((revs->max_parents >= 0) && (n > revs->max_parents)))
2804                        return commit_ignore;
2805        }
2806        if (!commit_match(commit, revs))
2807                return commit_ignore;
2808        if (revs->prune && revs->dense) {
2809                /* Commit without changes? */
2810                if (commit->object.flags & TREESAME) {
2811                        int n;
2812                        struct commit_list *p;
2813                        /* drop merges unless we want parenthood */
2814                        if (!want_ancestry(revs))
2815                                return commit_ignore;
2816                        /*
2817                         * If we want ancestry, then need to keep any merges
2818                         * between relevant commits to tie together topology.
2819                         * For consistency with TREESAME and simplification
2820                         * use "relevant" here rather than just INTERESTING,
2821                         * to treat bottom commit(s) as part of the topology.
2822                         */
2823                        for (n = 0, p = commit->parents; p; p = p->next)
2824                                if (relevant_commit(p->item))
2825                                        if (++n >= 2)
2826                                                return commit_show;
2827                        return commit_ignore;
2828                }
2829        }
2830        return commit_show;
2831}
2832
2833enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
2834{
2835        enum commit_action action = get_commit_action(revs, commit);
2836
2837        if (action == commit_show &&
2838            !revs->show_all &&
2839            revs->prune && revs->dense && want_ancestry(revs)) {
2840                /*
2841                 * --full-diff on simplified parents is no good: it
2842                 * will show spurious changes from the commits that
2843                 * were elided.  So we save the parents on the side
2844                 * when --full-diff is in effect.
2845                 */
2846                if (revs->full_diff)
2847                        save_parents(revs, commit);
2848                if (rewrite_parents(revs, commit, rewrite_one) < 0)
2849                        return commit_error;
2850        }
2851        return action;
2852}
2853
2854static struct commit *get_revision_1(struct rev_info *revs)
2855{
2856        if (!revs->commits)
2857                return NULL;
2858
2859        do {
2860                struct commit_list *entry = revs->commits;
2861                struct commit *commit = entry->item;
2862
2863                revs->commits = entry->next;
2864                free(entry);
2865
2866                if (revs->reflog_info) {
2867                        save_parents(revs, commit);
2868                        fake_reflog_parent(revs->reflog_info, commit);
2869                        commit->object.flags &= ~(ADDED | SEEN | SHOWN);
2870                }
2871
2872                /*
2873                 * If we haven't done the list limiting, we need to look at
2874                 * the parents here. We also need to do the date-based limiting
2875                 * that we'd otherwise have done in limit_list().
2876                 */
2877                if (!revs->limited) {
2878                        if (revs->max_age != -1 &&
2879                            (commit->date < revs->max_age))
2880                                continue;
2881                        if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0)
2882                                die("Failed to traverse parents of commit %s",
2883                                    sha1_to_hex(commit->object.sha1));
2884                }
2885
2886                switch (simplify_commit(revs, commit)) {
2887                case commit_ignore:
2888                        continue;
2889                case commit_error:
2890                        die("Failed to simplify parents of commit %s",
2891                            sha1_to_hex(commit->object.sha1));
2892                default:
2893                        return commit;
2894                }
2895        } while (revs->commits);
2896        return NULL;
2897}
2898
2899/*
2900 * Return true for entries that have not yet been shown.  (This is an
2901 * object_array_each_func_t.)
2902 */
2903static int entry_unshown(struct object_array_entry *entry, void *cb_data_unused)
2904{
2905        return !(entry->item->flags & SHOWN);
2906}
2907
2908/*
2909 * If array is on the verge of a realloc, garbage-collect any entries
2910 * that have already been shown to try to free up some space.
2911 */
2912static void gc_boundary(struct object_array *array)
2913{
2914        if (array->nr == array->alloc)
2915                object_array_filter(array, entry_unshown, NULL);
2916}
2917
2918static void create_boundary_commit_list(struct rev_info *revs)
2919{
2920        unsigned i;
2921        struct commit *c;
2922        struct object_array *array = &revs->boundary_commits;
2923        struct object_array_entry *objects = array->objects;
2924
2925        /*
2926         * If revs->commits is non-NULL at this point, an error occurred in
2927         * get_revision_1().  Ignore the error and continue printing the
2928         * boundary commits anyway.  (This is what the code has always
2929         * done.)
2930         */
2931        if (revs->commits) {
2932                free_commit_list(revs->commits);
2933                revs->commits = NULL;
2934        }
2935
2936        /*
2937         * Put all of the actual boundary commits from revs->boundary_commits
2938         * into revs->commits
2939         */
2940        for (i = 0; i < array->nr; i++) {
2941                c = (struct commit *)(objects[i].item);
2942                if (!c)
2943                        continue;
2944                if (!(c->object.flags & CHILD_SHOWN))
2945                        continue;
2946                if (c->object.flags & (SHOWN | BOUNDARY))
2947                        continue;
2948                c->object.flags |= BOUNDARY;
2949                commit_list_insert(c, &revs->commits);
2950        }
2951
2952        /*
2953         * If revs->topo_order is set, sort the boundary commits
2954         * in topological order
2955         */
2956        sort_in_topological_order(&revs->commits, revs->sort_order);
2957}
2958
2959static struct commit *get_revision_internal(struct rev_info *revs)
2960{
2961        struct commit *c = NULL;
2962        struct commit_list *l;
2963
2964        if (revs->boundary == 2) {
2965                /*
2966                 * All of the normal commits have already been returned,
2967                 * and we are now returning boundary commits.
2968                 * create_boundary_commit_list() has populated
2969                 * revs->commits with the remaining commits to return.
2970                 */
2971                c = pop_commit(&revs->commits);
2972                if (c)
2973                        c->object.flags |= SHOWN;
2974                return c;
2975        }
2976
2977        /*
2978         * If our max_count counter has reached zero, then we are done. We
2979         * don't simply return NULL because we still might need to show
2980         * boundary commits. But we want to avoid calling get_revision_1, which
2981         * might do a considerable amount of work finding the next commit only
2982         * for us to throw it away.
2983         *
2984         * If it is non-zero, then either we don't have a max_count at all
2985         * (-1), or it is still counting, in which case we decrement.
2986         */
2987        if (revs->max_count) {
2988                c = get_revision_1(revs);
2989                if (c) {
2990                        while (0 < revs->skip_count) {
2991                                revs->skip_count--;
2992                                c = get_revision_1(revs);
2993                                if (!c)
2994                                        break;
2995                        }
2996                }
2997
2998                if (revs->max_count > 0)
2999                        revs->max_count--;
3000        }
3001
3002        if (c)
3003                c->object.flags |= SHOWN;
3004
3005        if (!revs->boundary) {
3006                return c;
3007        }
3008
3009        if (!c) {
3010                /*
3011                 * get_revision_1() runs out the commits, and
3012                 * we are done computing the boundaries.
3013                 * switch to boundary commits output mode.
3014                 */
3015                revs->boundary = 2;
3016
3017                /*
3018                 * Update revs->commits to contain the list of
3019                 * boundary commits.
3020                 */
3021                create_boundary_commit_list(revs);
3022
3023                return get_revision_internal(revs);
3024        }
3025
3026        /*
3027         * boundary commits are the commits that are parents of the
3028         * ones we got from get_revision_1() but they themselves are
3029         * not returned from get_revision_1().  Before returning
3030         * 'c', we need to mark its parents that they could be boundaries.
3031         */
3032
3033        for (l = c->parents; l; l = l->next) {
3034                struct object *p;
3035                p = &(l->item->object);
3036                if (p->flags & (CHILD_SHOWN | SHOWN))
3037                        continue;
3038                p->flags |= CHILD_SHOWN;
3039                gc_boundary(&revs->boundary_commits);
3040                add_object_array(p, NULL, &revs->boundary_commits);
3041        }
3042
3043        return c;
3044}
3045
3046struct commit *get_revision(struct rev_info *revs)
3047{
3048        struct commit *c;
3049        struct commit_list *reversed;
3050
3051        if (revs->reverse) {
3052                reversed = NULL;
3053                while ((c = get_revision_internal(revs))) {
3054                        commit_list_insert(c, &reversed);
3055                }
3056                revs->commits = reversed;
3057                revs->reverse = 0;
3058                revs->reverse_output_stage = 1;
3059        }
3060
3061        if (revs->reverse_output_stage)
3062                return pop_commit(&revs->commits);
3063
3064        c = get_revision_internal(revs);
3065        if (c && revs->graph)
3066                graph_update(revs->graph, c);
3067        if (!c)
3068                free_saved_parents(revs);
3069        return c;
3070}
3071
3072char *get_revision_mark(const struct rev_info *revs, const struct commit *commit)
3073{
3074        if (commit->object.flags & BOUNDARY)
3075                return "-";
3076        else if (commit->object.flags & UNINTERESTING)
3077                return "^";
3078        else if (commit->object.flags & PATCHSAME)
3079                return "=";
3080        else if (!revs || revs->left_right) {
3081                if (commit->object.flags & SYMMETRIC_LEFT)
3082                        return "<";
3083                else
3084                        return ">";
3085        } else if (revs->graph)
3086                return "*";
3087        else if (revs->cherry_mark)
3088                return "+";
3089        return "";
3090}
3091
3092void put_revision_mark(const struct rev_info *revs, const struct commit *commit)
3093{
3094        char *mark = get_revision_mark(revs, commit);
3095        if (!strlen(mark))
3096                return;
3097        fputs(mark, stdout);
3098        putchar(' ');
3099}
3100
3101define_commit_slab(saved_parents, struct commit_list *);
3102
3103#define EMPTY_PARENT_LIST ((struct commit_list *)-1)
3104
3105void save_parents(struct rev_info *revs, struct commit *commit)
3106{
3107        struct commit_list **pp;
3108
3109        if (!revs->saved_parents_slab) {
3110                revs->saved_parents_slab = xmalloc(sizeof(struct saved_parents));
3111                init_saved_parents(revs->saved_parents_slab);
3112        }
3113
3114        pp = saved_parents_at(revs->saved_parents_slab, commit);
3115
3116        /*
3117         * When walking with reflogs, we may visit the same commit
3118         * several times: once for each appearance in the reflog.
3119         *
3120         * In this case, save_parents() will be called multiple times.
3121         * We want to keep only the first set of parents.  We need to
3122         * store a sentinel value for an empty (i.e., NULL) parent
3123         * list to distinguish it from a not-yet-saved list, however.
3124         */
3125        if (*pp)
3126                return;
3127        if (commit->parents)
3128                *pp = copy_commit_list(commit->parents);
3129        else
3130                *pp = EMPTY_PARENT_LIST;
3131}
3132
3133struct commit_list *get_saved_parents(struct rev_info *revs, const struct commit *commit)
3134{
3135        struct commit_list *parents;
3136
3137        if (!revs->saved_parents_slab)
3138                return commit->parents;
3139
3140        parents = *saved_parents_at(revs->saved_parents_slab, commit);
3141        if (parents == EMPTY_PARENT_LIST)
3142                return NULL;
3143        return parents;
3144}
3145
3146void free_saved_parents(struct rev_info *revs)
3147{
3148        if (revs->saved_parents_slab)
3149                clear_saved_parents(revs->saved_parents_slab);
3150}