revision.c

   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
  20 volatile show_early_output_fn_t show_early_output;
  21
  22 char *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
  46 static 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
  58 static 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
  75 void 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
  88 void 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
  98 static 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
 107 void 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);
 143         tree->buffer = NULL;
 144 }
 145
 146 void mark_parents_uninteresting(struct commit *commit)
 147 {
 148         struct commit_list *parents = NULL, *l;
 149
 150         for (l = commit->parents; l; l = l->next)
 151                 commit_list_insert(l->item, &parents);
 152
 153         while (parents) {
 154                 struct commit *commit = parents->item;
 155                 l = parents;
 156                 parents = parents->next;
 157                 free(l);
 158
 159                 while (commit) {
 160                         /*
 161                          * A missing commit is ok iff its parent is marked
 162                          * uninteresting.
 163                          *
 164                          * We just mark such a thing parsed, so that when
 165                          * it is popped next time around, we won't be trying
 166                          * to parse it and get an error.
 167                          */
 168                         if (!has_sha1_file(commit->object.sha1))
 169                                 commit->object.parsed = 1;
 170
 171                         if (commit->object.flags & UNINTERESTING)
 172                                 break;
 173
 174                         commit->object.flags |= UNINTERESTING;
 175
 176                         /*
 177                          * Normally we haven't parsed the parent
 178                          * yet, so we won't have a parent of a parent
 179                          * here. However, it may turn out that we've
 180                          * reached this commit some other way (where it
 181                          * wasn't uninteresting), in which case we need
 182                          * to mark its parents recursively too..
 183                          */
 184                         if (!commit->parents)
 185                                 break;
 186
 187                         for (l = commit->parents->next; l; l = l->next)
 188                                 commit_list_insert(l->item, &parents);
 189                         commit = commit->parents->item;
 190                 }
 191         }
 192 }
 193
 194 static void add_pending_object_with_mode(struct rev_info *revs,
 195                                          struct object *obj,
 196                                          const char *name, unsigned mode)
 197 {
 198         if (!obj)
 199                 return;
 200         if (revs->no_walk && (obj->flags & UNINTERESTING))
 201                 revs->no_walk = 0;
 202         if (revs->reflog_info && obj->type == OBJ_COMMIT) {
 203                 struct strbuf buf = STRBUF_INIT;
 204                 int len = interpret_branch_name(name, &buf);
 205                 int st;
 206
 207                 if (0 < len && name[len] && buf.len)
 208                         strbuf_addstr(&buf, name + len);
 209                 st = add_reflog_for_walk(revs->reflog_info,
 210                                          (struct commit *)obj,
 211                                          buf.buf[0] ? buf.buf: name);
 212                 strbuf_release(&buf);
 213                 if (st)
 214                         return;
 215         }
 216         add_object_array_with_mode(obj, name, &revs->pending, mode);
 217 }
 218
 219 void add_pending_object(struct rev_info *revs,
 220                         struct object *obj, const char *name)
 221 {
 222         add_pending_object_with_mode(revs, obj, name, S_IFINVALID);
 223 }
 224
 225 void add_head_to_pending(struct rev_info *revs)
 226 {
 227         unsigned char sha1[20];
 228         struct object *obj;
 229         if (get_sha1("HEAD", sha1))
 230                 return;
 231         obj = parse_object(sha1);
 232         if (!obj)
 233                 return;
 234         add_pending_object(revs, obj, "HEAD");
 235 }
 236
 237 static struct object *get_reference(struct rev_info *revs, const char *name,
 238                                     const unsigned char *sha1,
 239                                     unsigned int flags)
 240 {
 241         struct object *object;
 242
 243         object = parse_object(sha1);
 244         if (!object) {
 245                 if (revs->ignore_missing)
 246                         return object;
 247                 die("bad object %s", name);
 248         }
 249         object->flags |= flags;
 250         return object;
 251 }
 252
 253 void add_pending_sha1(struct rev_info *revs, const char *name,
 254                       const unsigned char *sha1, unsigned int flags)
 255 {
 256         struct object *object = get_reference(revs, name, sha1, flags);
 257         add_pending_object(revs, object, name);
 258 }
 259
 260 static struct commit *handle_commit(struct rev_info *revs,
 261                                     struct object *object, const char *name)
 262 {
 263         unsigned long flags = object->flags;
 264
 265         /*
 266          * Tag object? Look what it points to..
 267          */
 268         while (object->type == OBJ_TAG) {
 269                 struct tag *tag = (struct tag *) object;
 270                 if (revs->tag_objects && !(flags & UNINTERESTING))
 271                         add_pending_object(revs, object, tag->tag);
 272                 if (!tag->tagged)
 273                         die("bad tag");
 274                 object = parse_object(tag->tagged->sha1);
 275                 if (!object) {
 276                         if (flags & UNINTERESTING)
 277                                 return NULL;
 278                         die("bad object %s", sha1_to_hex(tag->tagged->sha1));
 279                 }
 280         }
 281
 282         /*
 283          * Commit object? Just return it, we'll do all the complex
 284          * reachability crud.
 285          */
 286         if (object->type == OBJ_COMMIT) {
 287                 struct commit *commit = (struct commit *)object;
 288                 if (parse_commit(commit) < 0)
 289                         die("unable to parse commit %s", name);
 290                 if (flags & UNINTERESTING) {
 291                         commit->object.flags |= UNINTERESTING;
 292                         mark_parents_uninteresting(commit);
 293                         revs->limited = 1;
 294                 }
 295                 if (revs->show_source && !commit->util)
 296                         commit->util = (void *) name;
 297                 return commit;
 298         }
 299
 300         /*
 301          * Tree object? Either mark it uninteresting, or add it
 302          * to the list of objects to look at later..
 303          */
 304         if (object->type == OBJ_TREE) {
 305                 struct tree *tree = (struct tree *)object;
 306                 if (!revs->tree_objects)
 307                         return NULL;
 308                 if (flags & UNINTERESTING) {
 309                         mark_tree_uninteresting(tree);
 310                         return NULL;
 311                 }
 312                 add_pending_object(revs, object, "");
 313                 return NULL;
 314         }
 315
 316         /*
 317          * Blob object? You know the drill by now..
 318          */
 319         if (object->type == OBJ_BLOB) {
 320                 struct blob *blob = (struct blob *)object;
 321                 if (!revs->blob_objects)
 322                         return NULL;
 323                 if (flags & UNINTERESTING) {
 324                         mark_blob_uninteresting(blob);
 325                         return NULL;
 326                 }
 327                 add_pending_object(revs, object, "");
 328                 return NULL;
 329         }
 330         die("%s is unknown object", name);
 331 }
 332
 333 static int everybody_uninteresting(struct commit_list *orig)
 334 {
 335         struct commit_list *list = orig;
 336         while (list) {
 337                 struct commit *commit = list->item;
 338                 list = list->next;
 339                 if (commit->object.flags & UNINTERESTING)
 340                         continue;
 341                 return 0;
 342         }
 343         return 1;
 344 }
 345
 346 /*
 347  * A definition of "relevant" commit that we can use to simplify limited graphs
 348  * by eliminating side branches.
 349  *
 350  * A "relevant" commit is one that is !UNINTERESTING (ie we are including it
 351  * in our list), or that is a specified BOTTOM commit. Then after computing
 352  * a limited list, during processing we can generally ignore boundary merges
 353  * coming from outside the graph, (ie from irrelevant parents), and treat
 354  * those merges as if they were single-parent. TREESAME is defined to consider
 355  * only relevant parents, if any. If we are TREESAME to our on-graph parents,
 356  * we don't care if we were !TREESAME to non-graph parents.
 357  *
 358  * Treating bottom commits as relevant ensures that a limited graph's
 359  * connection to the actual bottom commit is not viewed as a side branch, but
 360  * treated as part of the graph. For example:
 361  *
 362  *   ....Z...A---X---o---o---B
 363  *        .     /
 364  *         W---Y
 365  *
 366  * When computing "A..B", the A-X connection is at least as important as
 367  * Y-X, despite A being flagged UNINTERESTING.
 368  *
 369  * And when computing --ancestry-path "A..B", the A-X connection is more
 370  * important than Y-X, despite both A and Y being flagged UNINTERESTING.
 371  */
 372 static inline int relevant_commit(struct commit *commit)
 373 {
 374         return (commit->object.flags & (UNINTERESTING | BOTTOM)) != UNINTERESTING;
 375 }
 376
 377 /*
 378  * Return a single relevant commit from a parent list. If we are a TREESAME
 379  * commit, and this selects one of our parents, then we can safely simplify to
 380  * that parent.
 381  */
 382 static struct commit *one_relevant_parent(const struct rev_info *revs,
 383                                           struct commit_list *orig)
 384 {
 385         struct commit_list *list = orig;
 386         struct commit *relevant = NULL;
 387
 388         if (!orig)
 389                 return NULL;
 390
 391         /*
 392          * For 1-parent commits, or if first-parent-only, then return that
 393          * first parent (even if not "relevant" by the above definition).
 394          * TREESAME will have been set purely on that parent.
 395          */
 396         if (revs->first_parent_only || !orig->next)
 397                 return orig->item;
 398
 399         /*
 400          * For multi-parent commits, identify a sole relevant parent, if any.
 401          * If we have only one relevant parent, then TREESAME will be set purely
 402          * with regard to that parent, and we can simplify accordingly.
 403          *
 404          * If we have more than one relevant parent, or no relevant parents
 405          * (and multiple irrelevant ones), then we can't select a parent here
 406          * and return NULL.
 407          */
 408         while (list) {
 409                 struct commit *commit = list->item;
 410                 list = list->next;
 411                 if (relevant_commit(commit)) {
 412                         if (relevant)
 413                                 return NULL;
 414                         relevant = commit;
 415                 }
 416         }
 417         return relevant;
 418 }
 419
 420 /*
 421  * The goal is to get REV_TREE_NEW as the result only if the
 422  * diff consists of all '+' (and no other changes), REV_TREE_OLD
 423  * if the whole diff is removal of old data, and otherwise
 424  * REV_TREE_DIFFERENT (of course if the trees are the same we
 425  * want REV_TREE_SAME).
 426  * That means that once we get to REV_TREE_DIFFERENT, we do not
 427  * have to look any further.
 428  */
 429 static int tree_difference = REV_TREE_SAME;
 430
 431 static void file_add_remove(struct diff_options *options,
 432                     int addremove, unsigned mode,
 433                     const unsigned char *sha1,
 434                     int sha1_valid,
 435                     const char *fullpath, unsigned dirty_submodule)
 436 {
 437         int diff = addremove == '+' ? REV_TREE_NEW : REV_TREE_OLD;
 438
 439         tree_difference |= diff;
 440         if (tree_difference == REV_TREE_DIFFERENT)
 441                 DIFF_OPT_SET(options, HAS_CHANGES);
 442 }
 443
 444 static void file_change(struct diff_options *options,
 445                  unsigned old_mode, unsigned new_mode,
 446                  const unsigned char *old_sha1,
 447                  const unsigned char *new_sha1,
 448                  int old_sha1_valid, int new_sha1_valid,
 449                  const char *fullpath,
 450                  unsigned old_dirty_submodule, unsigned new_dirty_submodule)
 451 {
 452         tree_difference = REV_TREE_DIFFERENT;
 453         DIFF_OPT_SET(options, HAS_CHANGES);
 454 }
 455
 456 static int rev_compare_tree(struct rev_info *revs,
 457                             struct commit *parent, struct commit *commit)
 458 {
 459         struct tree *t1 = parent->tree;
 460         struct tree *t2 = commit->tree;
 461
 462         if (!t1)
 463                 return REV_TREE_NEW;
 464         if (!t2)
 465                 return REV_TREE_OLD;
 466
 467         if (revs->simplify_by_decoration) {
 468                 /*
 469                  * If we are simplifying by decoration, then the commit
 470                  * is worth showing if it has a tag pointing at it.
 471                  */
 472                 if (lookup_decoration(&name_decoration, &commit->object))
 473                         return REV_TREE_DIFFERENT;
 474                 /*
 475                  * A commit that is not pointed by a tag is uninteresting
 476                  * if we are not limited by path.  This means that you will
 477                  * see the usual "commits that touch the paths" plus any
 478                  * tagged commit by specifying both --simplify-by-decoration
 479                  * and pathspec.
 480                  */
 481                 if (!revs->prune_data.nr)
 482                         return REV_TREE_SAME;
 483         }
 484
 485         tree_difference = REV_TREE_SAME;
 486         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 487         if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
 488                            &revs->pruning) < 0)
 489                 return REV_TREE_DIFFERENT;
 490         return tree_difference;
 491 }
 492
 493 static int rev_same_tree_as_empty(struct rev_info *revs, struct commit *commit)
 494 {
 495         int retval;
 496         void *tree;
 497         unsigned long size;
 498         struct tree_desc empty, real;
 499         struct tree *t1 = commit->tree;
 500
 501         if (!t1)
 502                 return 0;
 503
 504         tree = read_object_with_reference(t1->object.sha1, tree_type, &size, NULL);
 505         if (!tree)
 506                 return 0;
 507         init_tree_desc(&real, tree, size);
 508         init_tree_desc(&empty, "", 0);
 509
 510         tree_difference = REV_TREE_SAME;
 511         DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 512         retval = diff_tree(&empty, &real, "", &revs->pruning);
 513         free(tree);
 514
 515         return retval >= 0 && (tree_difference == REV_TREE_SAME);
 516 }
 517
 518 struct treesame_state {
 519         unsigned int nparents;
 520         unsigned char treesame[FLEX_ARRAY];
 521 };
 522
 523 static struct treesame_state *initialise_treesame(struct rev_info *revs, struct commit *commit)
 524 {
 525         unsigned n = commit_list_count(commit->parents);
 526         struct treesame_state *st = xcalloc(1, sizeof(*st) + n);
 527         st->nparents = n;
 528         add_decoration(&revs->treesame, &commit->object, st);
 529         return st;
 530 }
 531
 532 /*
 533  * Must be called immediately after removing the nth_parent from a commit's
 534  * parent list, if we are maintaining the per-parent treesame[] decoration.
 535  * This does not recalculate the master TREESAME flag - update_treesame()
 536  * should be called to update it after a sequence of treesame[] modifications
 537  * that may have affected it.
 538  */
 539 static int compact_treesame(struct rev_info *revs, struct commit *commit, unsigned nth_parent)
 540 {
 541         struct treesame_state *st;
 542         int old_same;
 543
 544         if (!commit->parents) {
 545                 /*
 546                  * Have just removed the only parent from a non-merge.
 547                  * Different handling, as we lack decoration.
 548                  */
 549                 if (nth_parent != 0)
 550                         die("compact_treesame %u", nth_parent);
 551                 old_same = !!(commit->object.flags & TREESAME);
 552                 if (rev_same_tree_as_empty(revs, commit))
 553                         commit->object.flags |= TREESAME;
 554                 else
 555                         commit->object.flags &= ~TREESAME;
 556                 return old_same;
 557         }
 558
 559         st = lookup_decoration(&revs->treesame, &commit->object);
 560         if (!st || nth_parent >= st->nparents)
 561                 die("compact_treesame %u", nth_parent);
 562
 563         old_same = st->treesame[nth_parent];
 564         memmove(st->treesame + nth_parent,
 565                 st->treesame + nth_parent + 1,
 566                 st->nparents - nth_parent - 1);
 567
 568         /*
 569          * If we've just become a non-merge commit, update TREESAME
 570          * immediately, and remove the no-longer-needed decoration.
 571          * If still a merge, defer update until update_treesame().
 572          */
 573         if (--st->nparents == 1) {
 574                 if (commit->parents->next)
 575                         die("compact_treesame parents mismatch");
 576                 if (st->treesame[0] && revs->dense)
 577                         commit->object.flags |= TREESAME;
 578                 else
 579                         commit->object.flags &= ~TREESAME;
 580                 free(add_decoration(&revs->treesame, &commit->object, NULL));
 581         }
 582
 583         return old_same;
 584 }
 585
 586 static unsigned update_treesame(struct rev_info *revs, struct commit *commit)
 587 {
 588         if (commit->parents && commit->parents->next) {
 589                 unsigned n;
 590                 struct treesame_state *st;
 591                 struct commit_list *p;
 592                 unsigned relevant_parents;
 593                 unsigned relevant_change, irrelevant_change;
 594
 595                 st = lookup_decoration(&revs->treesame, &commit->object);
 596                 if (!st)
 597                         die("update_treesame %s", sha1_to_hex(commit->object.sha1));
 598                 relevant_parents = 0;
 599                 relevant_change = irrelevant_change = 0;
 600                 for (p = commit->parents, n = 0; p; n++, p = p->next) {
 601                         if (relevant_commit(p->item)) {
 602                                 relevant_change |= !st->treesame[n];
 603                                 relevant_parents++;
 604                         } else
 605                                 irrelevant_change |= !st->treesame[n];
 606                 }
 607                 if (relevant_parents ? relevant_change : irrelevant_change)
 608                         commit->object.flags &= ~TREESAME;
 609                 else
 610                         commit->object.flags |= TREESAME;
 611         }
 612
 613         return commit->object.flags & TREESAME;
 614 }
 615
 616 static inline int limiting_can_increase_treesame(const struct rev_info *revs)
 617 {
 618         /*
 619          * TREESAME is irrelevant unless prune && dense;
 620          * if simplify_history is set, we can't have a mixture of TREESAME and
 621          *    !TREESAME INTERESTING parents (and we don't have treesame[]
 622          *    decoration anyway);
 623          * if first_parent_only is set, then the TREESAME flag is locked
 624          *    against the first parent (and again we lack treesame[] decoration).
 625          */
 626         return revs->prune && revs->dense &&
 627                !revs->simplify_history &&
 628                !revs->first_parent_only;
 629 }
 630
 631 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 632 {
 633         struct commit_list **pp, *parent;
 634         struct treesame_state *ts = NULL;
 635         int relevant_change = 0, irrelevant_change = 0;
 636         int relevant_parents, nth_parent;
 637
 638         /*
 639          * If we don't do pruning, everything is interesting
 640          */
 641         if (!revs->prune)
 642                 return;
 643
 644         if (!commit->tree)
 645                 return;
 646
 647         if (!commit->parents) {
 648                 if (rev_same_tree_as_empty(revs, commit))
 649                         commit->object.flags |= TREESAME;
 650                 return;
 651         }
 652
 653         /*
 654          * Normal non-merge commit? If we don't want to make the
 655          * history dense, we consider it always to be a change..
 656          */
 657         if (!revs->dense && !commit->parents->next)
 658                 return;
 659
 660         for (pp = &commit->parents, nth_parent = 0, relevant_parents = 0;
 661              (parent = *pp) != NULL;
 662              pp = &parent->next, nth_parent++) {
 663                 struct commit *p = parent->item;
 664                 if (relevant_commit(p))
 665                         relevant_parents++;
 666
 667                 if (nth_parent == 1) {
 668                         /*
 669                          * This our second loop iteration - so we now know
 670                          * we're dealing with a merge.
 671                          *
 672                          * Do not compare with later parents when we care only about
 673                          * the first parent chain, in order to avoid derailing the
 674                          * traversal to follow a side branch that brought everything
 675                          * in the path we are limited to by the pathspec.
 676                          */
 677                         if (revs->first_parent_only)
 678                                 break;
 679                         /*
 680                          * If this will remain a potentially-simplifiable
 681                          * merge, remember per-parent treesame if needed.
 682                          * Initialise the array with the comparison from our
 683                          * first iteration.
 684                          */
 685                         if (revs->treesame.name &&
 686                             !revs->simplify_history &&
 687                             !(commit->object.flags & UNINTERESTING)) {
 688                                 ts = initialise_treesame(revs, commit);
 689                                 if (!(irrelevant_change || relevant_change))
 690                                         ts->treesame[0] = 1;
 691                         }
 692                 }
 693                 if (parse_commit(p) < 0)
 694                         die("cannot simplify commit %s (because of %s)",
 695                             sha1_to_hex(commit->object.sha1),
 696                             sha1_to_hex(p->object.sha1));
 697                 switch (rev_compare_tree(revs, p, commit)) {
 698                 case REV_TREE_SAME:
 699                         if (!revs->simplify_history || !relevant_commit(p)) {
 700                                 /* Even if a merge with an uninteresting
 701                                  * side branch brought the entire change
 702                                  * we are interested in, we do not want
 703                                  * to lose the other branches of this
 704                                  * merge, so we just keep going.
 705                                  */
 706                                 if (ts)
 707                                         ts->treesame[nth_parent] = 1;
 708                                 continue;
 709                         }
 710                         parent->next = NULL;
 711                         commit->parents = parent;
 712                         commit->object.flags |= TREESAME;
 713                         return;
 714
 715                 case REV_TREE_NEW:
 716                         if (revs->remove_empty_trees &&
 717                             rev_same_tree_as_empty(revs, p)) {
 718                                 /* We are adding all the specified
 719                                  * paths from this parent, so the
 720                                  * history beyond this parent is not
 721                                  * interesting.  Remove its parents
 722                                  * (they are grandparents for us).
 723                                  * IOW, we pretend this parent is a
 724                                  * "root" commit.
 725                                  */
 726                                 if (parse_commit(p) < 0)
 727                                         die("cannot simplify commit %s (invalid %s)",
 728                                             sha1_to_hex(commit->object.sha1),
 729                                             sha1_to_hex(p->object.sha1));
 730                                 p->parents = NULL;
 731                         }
 732                 /* fallthrough */
 733                 case REV_TREE_OLD:
 734                 case REV_TREE_DIFFERENT:
 735                         if (relevant_commit(p))
 736                                 relevant_change = 1;
 737                         else
 738                                 irrelevant_change = 1;
 739                         continue;
 740                 }
 741                 die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
 742         }
 743
 744         /*
 745          * TREESAME is straightforward for single-parent commits. For merge
 746          * commits, it is most useful to define it so that "irrelevant"
 747          * parents cannot make us !TREESAME - if we have any relevant
 748          * parents, then we only consider TREESAMEness with respect to them,
 749          * allowing irrelevant merges from uninteresting branches to be
 750          * simplified away. Only if we have only irrelevant parents do we
 751          * base TREESAME on them. Note that this logic is replicated in
 752          * update_treesame, which should be kept in sync.
 753          */
 754         if (relevant_parents ? !relevant_change : !irrelevant_change)
 755                 commit->object.flags |= TREESAME;
 756 }
 757
 758 static void commit_list_insert_by_date_cached(struct commit *p, struct commit_list **head,
 759                     struct commit_list *cached_base, struct commit_list **cache)
 760 {
 761         struct commit_list *new_entry;
 762
 763         if (cached_base && p->date < cached_base->item->date)
 764                 new_entry = commit_list_insert_by_date(p, &cached_base->next);
 765         else
 766                 new_entry = commit_list_insert_by_date(p, head);
 767
 768         if (cache && (!*cache || p->date < (*cache)->item->date))
 769                 *cache = new_entry;
 770 }
 771
 772 static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
 773                     struct commit_list **list, struct commit_list **cache_ptr)
 774 {
 775         struct commit_list *parent = commit->parents;
 776         unsigned left_flag;
 777         struct commit_list *cached_base = cache_ptr ? *cache_ptr : NULL;
 778
 779         if (commit->object.flags & ADDED)
 780                 return 0;
 781         commit->object.flags |= ADDED;
 782
 783         /*
 784          * If the commit is uninteresting, don't try to
 785          * prune parents - we want the maximal uninteresting
 786          * set.
 787          *
 788          * Normally we haven't parsed the parent
 789          * yet, so we won't have a parent of a parent
 790          * here. However, it may turn out that we've
 791          * reached this commit some other way (where it
 792          * wasn't uninteresting), in which case we need
 793          * to mark its parents recursively too..
 794          */
 795         if (commit->object.flags & UNINTERESTING) {
 796                 while (parent) {
 797                         struct commit *p = parent->item;
 798                         parent = parent->next;
 799                         if (p)
 800                                 p->object.flags |= UNINTERESTING;
 801                         if (parse_commit(p) < 0)
 802                                 continue;
 803                         if (p->parents)
 804                                 mark_parents_uninteresting(p);
 805                         if (p->object.flags & SEEN)
 806                                 continue;
 807                         p->object.flags |= SEEN;
 808                         commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
 809                 }
 810                 return 0;
 811         }
 812
 813         /*
 814          * Ok, the commit wasn't uninteresting. Try to
 815          * simplify the commit history and find the parent
 816          * that has no differences in the path set if one exists.
 817          */
 818         try_to_simplify_commit(revs, commit);
 819
 820         if (revs->no_walk)
 821                 return 0;
 822
 823         left_flag = (commit->object.flags & SYMMETRIC_LEFT);
 824
 825         for (parent = commit->parents; parent; parent = parent->next) {
 826                 struct commit *p = parent->item;
 827
 828                 if (parse_commit(p) < 0)
 829                         return -1;
 830                 if (revs->show_source && !p->util)
 831                         p->util = commit->util;
 832                 p->object.flags |= left_flag;
 833                 if (!(p->object.flags & SEEN)) {
 834                         p->object.flags |= SEEN;
 835                         commit_list_insert_by_date_cached(p, list, cached_base, cache_ptr);
 836                 }
 837                 if (revs->first_parent_only)
 838                         break;
 839         }
 840         return 0;
 841 }
 842
 843 static void cherry_pick_list(struct commit_list *list, struct rev_info *revs)
 844 {
 845         struct commit_list *p;
 846         int left_count = 0, right_count = 0;
 847         int left_first;
 848         struct patch_ids ids;
 849         unsigned cherry_flag;
 850
 851         /* First count the commits on the left and on the right */
 852         for (p = list; p; p = p->next) {
 853                 struct commit *commit = p->item;
 854                 unsigned flags = commit->object.flags;
 855                 if (flags & BOUNDARY)
 856                         ;
 857                 else if (flags & SYMMETRIC_LEFT)
 858                         left_count++;
 859                 else
 860                         right_count++;
 861         }
 862
 863         if (!left_count || !right_count)
 864                 return;
 865
 866         left_first = left_count < right_count;
 867         init_patch_ids(&ids);
 868         ids.diffopts.pathspec = revs->diffopt.pathspec;
 869
 870         /* Compute patch-ids for one side */
 871         for (p = list; p; p = p->next) {
 872                 struct commit *commit = p->item;
 873                 unsigned flags = commit->object.flags;
 874
 875                 if (flags & BOUNDARY)
 876                         continue;
 877                 /*
 878                  * If we have fewer left, left_first is set and we omit
 879                  * commits on the right branch in this loop.  If we have
 880                  * fewer right, we skip the left ones.
 881                  */
 882                 if (left_first != !!(flags & SYMMETRIC_LEFT))
 883                         continue;
 884                 commit->util = add_commit_patch_id(commit, &ids);
 885         }
 886
 887         /* either cherry_mark or cherry_pick are true */
 888         cherry_flag = revs->cherry_mark ? PATCHSAME : SHOWN;
 889
 890         /* Check the other side */
 891         for (p = list; p; p = p->next) {
 892                 struct commit *commit = p->item;
 893                 struct patch_id *id;
 894                 unsigned flags = commit->object.flags;
 895
 896                 if (flags & BOUNDARY)
 897                         continue;
 898                 /*
 899                  * If we have fewer left, left_first is set and we omit
 900                  * commits on the left branch in this loop.
 901                  */
 902                 if (left_first == !!(flags & SYMMETRIC_LEFT))
 903                         continue;
 904
 905                 /*
 906                  * Have we seen the same patch id?
 907                  */
 908                 id = has_commit_patch_id(commit, &ids);
 909                 if (!id)
 910                         continue;
 911                 id->seen = 1;
 912                 commit->object.flags |= cherry_flag;
 913         }
 914
 915         /* Now check the original side for seen ones */
 916         for (p = list; p; p = p->next) {
 917                 struct commit *commit = p->item;
 918                 struct patch_id *ent;
 919
 920                 ent = commit->util;
 921                 if (!ent)
 922                         continue;
 923                 if (ent->seen)
 924                         commit->object.flags |= cherry_flag;
 925                 commit->util = NULL;
 926         }
 927
 928         free_patch_ids(&ids);
 929 }
 930
 931 /* How many extra uninteresting commits we want to see.. */
 932 #define SLOP 5
 933
 934 static int still_interesting(struct commit_list *src, unsigned long date, int slop)
 935 {
 936         /*
 937          * No source list at all? We're definitely done..
 938          */
 939         if (!src)
 940                 return 0;
 941
 942         /*
 943          * Does the destination list contain entries with a date
 944          * before the source list? Definitely _not_ done.
 945          */
 946         if (date <= src->item->date)
 947                 return SLOP;
 948
 949         /*
 950          * Does the source list still have interesting commits in
 951          * it? Definitely not done..
 952          */
 953         if (!everybody_uninteresting(src))
 954                 return SLOP;
 955
 956         /* Ok, we're closing in.. */
 957         return slop-1;
 958 }
 959
 960 /*
 961  * "rev-list --ancestry-path A..B" computes commits that are ancestors
 962  * of B but not ancestors of A but further limits the result to those
 963  * that are descendants of A.  This takes the list of bottom commits and
 964  * the result of "A..B" without --ancestry-path, and limits the latter
 965  * further to the ones that can reach one of the commits in "bottom".
 966  */
 967 static void limit_to_ancestry(struct commit_list *bottom, struct commit_list *list)
 968 {
 969         struct commit_list *p;
 970         struct commit_list *rlist = NULL;
 971         int made_progress;
 972
 973         /*
 974          * Reverse the list so that it will be likely that we would
 975          * process parents before children.
 976          */
 977         for (p = list; p; p = p->next)
 978                 commit_list_insert(p->item, &rlist);
 979
 980         for (p = bottom; p; p = p->next)
 981                 p->item->object.flags |= TMP_MARK;
 982
 983         /*
 984          * Mark the ones that can reach bottom commits in "list",
 985          * in a bottom-up fashion.
 986          */
 987         do {
 988                 made_progress = 0;
 989                 for (p = rlist; p; p = p->next) {
 990                         struct commit *c = p->item;
 991                         struct commit_list *parents;
 992                         if (c->object.flags & (TMP_MARK | UNINTERESTING))
 993                                 continue;
 994                         for (parents = c->parents;
 995                              parents;
 996                              parents = parents->next) {
 997                                 if (!(parents->item->object.flags & TMP_MARK))
 998                                         continue;
 999                                 c->object.flags |= TMP_MARK;
1000                                 made_progress = 1;
1001                                 break;
1002                         }
1003                 }
1004         } while (made_progress);
1005
1006         /*
1007          * NEEDSWORK: decide if we want to remove parents that are
1008          * not marked with TMP_MARK from commit->parents for commits
1009          * in the resulting list.  We may not want to do that, though.
1010          */
1011
1012         /*
1013          * The ones that are not marked with TMP_MARK are uninteresting
1014          */
1015         for (p = list; p; p = p->next) {
1016                 struct commit *c = p->item;
1017                 if (c->object.flags & TMP_MARK)
1018                         continue;
1019                 c->object.flags |= UNINTERESTING;
1020         }
1021
1022         /* We are done with the TMP_MARK */
1023         for (p = list; p; p = p->next)
1024                 p->item->object.flags &= ~TMP_MARK;
1025         for (p = bottom; p; p = p->next)
1026                 p->item->object.flags &= ~TMP_MARK;
1027         free_commit_list(rlist);
1028 }
1029
1030 /*
1031  * Before walking the history, keep the set of "negative" refs the
1032  * caller has asked to exclude.
1033  *
1034  * This is used to compute "rev-list --ancestry-path A..B", as we need
1035  * to filter the result of "A..B" further to the ones that can actually
1036  * reach A.
1037  */
1038 static struct commit_list *collect_bottom_commits(struct commit_list *list)
1039 {
1040         struct commit_list *elem, *bottom = NULL;
1041         for (elem = list; elem; elem = elem->next)
1042                 if (elem->item->object.flags & BOTTOM)
1043                         commit_list_insert(elem->item, &bottom);
1044         return bottom;
1045 }
1046
1047 /* Assumes either left_only or right_only is set */
1048 static void limit_left_right(struct commit_list *list, struct rev_info *revs)
1049 {
1050         struct commit_list *p;
1051
1052         for (p = list; p; p = p->next) {
1053                 struct commit *commit = p->item;
1054
1055                 if (revs->right_only) {
1056                         if (commit->object.flags & SYMMETRIC_LEFT)
1057                                 commit->object.flags |= SHOWN;
1058                 } else  /* revs->left_only is set */
1059                         if (!(commit->object.flags & SYMMETRIC_LEFT))
1060                                 commit->object.flags |= SHOWN;
1061         }
1062 }
1063
1064 static int limit_list(struct rev_info *revs)
1065 {
1066         int slop = SLOP;
1067         unsigned long date = ~0ul;
1068         struct commit_list *list = revs->commits;
1069         struct commit_list *newlist = NULL;
1070         struct commit_list **p = &newlist;
1071         struct commit_list *bottom = NULL;
1072
1073         if (revs->ancestry_path) {
1074                 bottom = collect_bottom_commits(list);
1075                 if (!bottom)
1076                         die("--ancestry-path given but there are no bottom commits");
1077         }
1078
1079         while (list) {
1080                 struct commit_list *entry = list;
1081                 struct commit *commit = list->item;
1082                 struct object *obj = &commit->object;
1083                 show_early_output_fn_t show;
1084
1085                 list = list->next;
1086                 free(entry);
1087
1088                 if (revs->max_age != -1 && (commit->date < revs->max_age))
1089                         obj->flags |= UNINTERESTING;
1090                 if (add_parents_to_list(revs, commit, &list, NULL) < 0)
1091                         return -1;
1092                 if (obj->flags & UNINTERESTING) {
1093                         mark_parents_uninteresting(commit);
1094                         if (revs->show_all)
1095                                 p = &commit_list_insert(commit, p)->next;
1096                         slop = still_interesting(list, date, slop);
1097                         if (slop)
1098                                 continue;
1099                         /* If showing all, add the whole pending list to the end */
1100                         if (revs->show_all)
1101                                 *p = list;
1102                         break;
1103                 }
1104                 if (revs->min_age != -1 && (commit->date > revs->min_age))
1105                         continue;
1106                 date = commit->date;
1107                 p = &commit_list_insert(commit, p)->next;
1108
1109                 show = show_early_output;
1110                 if (!show)
1111                         continue;
1112
1113                 show(revs, newlist);
1114                 show_early_output = NULL;
1115         }
1116         if (revs->cherry_pick || revs->cherry_mark)
1117                 cherry_pick_list(newlist, revs);
1118
1119         if (revs->left_only || revs->right_only)
1120                 limit_left_right(newlist, revs);
1121
1122         if (bottom) {
1123                 limit_to_ancestry(bottom, newlist);
1124                 free_commit_list(bottom);
1125         }
1126
1127         /*
1128          * Check if any commits have become TREESAME by some of their parents
1129          * becoming UNINTERESTING.
1130          */
1131         if (limiting_can_increase_treesame(revs))
1132                 for (list = newlist; list; list = list->next) {
1133                         struct commit *c = list->item;
1134                         if (c->object.flags & (UNINTERESTING | TREESAME))
1135                                 continue;
1136                         update_treesame(revs, c);
1137                 }
1138
1139         revs->commits = newlist;
1140         return 0;
1141 }
1142
1143 /*
1144  * Add an entry to refs->cmdline with the specified information.
1145  * *name is copied.
1146  */
1147 static void add_rev_cmdline(struct rev_info *revs,
1148                             struct object *item,
1149                             const char *name,
1150                             int whence,
1151                             unsigned flags)
1152 {
1153         struct rev_cmdline_info *info = &revs->cmdline;
1154         int nr = info->nr;
1155
1156         ALLOC_GROW(info->rev, nr + 1, info->alloc);
1157         info->rev[nr].item = item;
1158         info->rev[nr].name = xstrdup(name);
1159         info->rev[nr].whence = whence;
1160         info->rev[nr].flags = flags;
1161         info->nr++;
1162 }
1163
1164 static void add_rev_cmdline_list(struct rev_info *revs,
1165                                  struct commit_list *commit_list,
1166                                  int whence,
1167                                  unsigned flags)
1168 {
1169         while (commit_list) {
1170                 struct object *object = &commit_list->item->object;
1171                 add_rev_cmdline(revs, object, sha1_to_hex(object->sha1),
1172                                 whence, flags);
1173                 commit_list = commit_list->next;
1174         }
1175 }
1176
1177 struct all_refs_cb {
1178         int all_flags;
1179         int warned_bad_reflog;
1180         struct rev_info *all_revs;
1181         const char *name_for_errormsg;
1182 };
1183
1184 static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1185 {
1186         struct all_refs_cb *cb = cb_data;
1187         struct object *object = get_reference(cb->all_revs, path, sha1,
1188                                               cb->all_flags);
1189         add_rev_cmdline(cb->all_revs, object, path, REV_CMD_REF, cb->all_flags);
1190         add_pending_sha1(cb->all_revs, path, sha1, cb->all_flags);
1191         return 0;
1192 }
1193
1194 static void init_all_refs_cb(struct all_refs_cb *cb, struct rev_info *revs,
1195         unsigned flags)
1196 {
1197         cb->all_revs = revs;
1198         cb->all_flags = flags;
1199 }
1200
1201 static void handle_refs(const char *submodule, struct rev_info *revs, unsigned flags,
1202                 int (*for_each)(const char *, each_ref_fn, void *))
1203 {
1204         struct all_refs_cb cb;
1205         init_all_refs_cb(&cb, revs, flags);
1206         for_each(submodule, handle_one_ref, &cb);
1207 }
1208
1209 static void handle_one_reflog_commit(unsigned char *sha1, void *cb_data)
1210 {
1211         struct all_refs_cb *cb = cb_data;
1212         if (!is_null_sha1(sha1)) {
1213                 struct object *o = parse_object(sha1);
1214                 if (o) {
1215                         o->flags |= cb->all_flags;
1216                         /* ??? CMDLINEFLAGS ??? */
1217                         add_pending_object(cb->all_revs, o, "");
1218                 }
1219                 else if (!cb->warned_bad_reflog) {
1220                         warning("reflog of '%s' references pruned commits",
1221                                 cb->name_for_errormsg);
1222                         cb->warned_bad_reflog = 1;
1223                 }
1224         }
1225 }
1226
1227 static int handle_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
1228                 const char *email, unsigned long timestamp, int tz,
1229                 const char *message, void *cb_data)
1230 {
1231         handle_one_reflog_commit(osha1, cb_data);
1232         handle_one_reflog_commit(nsha1, cb_data);
1233         return 0;
1234 }
1235
1236 static int handle_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
1237 {
1238         struct all_refs_cb *cb = cb_data;
1239         cb->warned_bad_reflog = 0;
1240         cb->name_for_errormsg = path;
1241         for_each_reflog_ent(path, handle_one_reflog_ent, cb_data);
1242         return 0;
1243 }
1244
1245 static void handle_reflog(struct rev_info *revs, unsigned flags)
1246 {
1247         struct all_refs_cb cb;
1248         cb.all_revs = revs;
1249         cb.all_flags = flags;
1250         for_each_reflog(handle_one_reflog, &cb);
1251 }
1252
1253 static int add_parents_only(struct rev_info *revs, const char *arg_, int flags)
1254 {
1255         unsigned char sha1[20];
1256         struct object *it;
1257         struct commit *commit;
1258         struct commit_list *parents;
1259         const char *arg = arg_;
1260
1261         if (*arg == '^') {
1262                 flags ^= UNINTERESTING | BOTTOM;
1263                 arg++;
1264         }
1265         if (get_sha1_committish(arg, sha1))
1266                 return 0;
1267         while (1) {
1268                 it = get_reference(revs, arg, sha1, 0);
1269                 if (!it && revs->ignore_missing)
1270                         return 0;
1271                 if (it->type != OBJ_TAG)
1272                         break;
1273                 if (!((struct tag*)it)->tagged)
1274                         return 0;
1275                 hashcpy(sha1, ((struct tag*)it)->tagged->sha1);
1276         }
1277         if (it->type != OBJ_COMMIT)
1278                 return 0;
1279         commit = (struct commit *)it;
1280         for (parents = commit->parents; parents; parents = parents->next) {
1281                 it = &parents->item->object;
1282                 it->flags |= flags;
1283                 add_rev_cmdline(revs, it, arg_, REV_CMD_PARENTS_ONLY, flags);
1284                 add_pending_object(revs, it, arg);
1285         }
1286         return 1;
1287 }
1288
1289 void init_revisions(struct rev_info *revs, const char *prefix)
1290 {
1291         memset(revs, 0, sizeof(*revs));
1292
1293         revs->abbrev = DEFAULT_ABBREV;
1294         revs->ignore_merges = 1;
1295         revs->simplify_history = 1;
1296         DIFF_OPT_SET(&revs->pruning, RECURSIVE);
1297         DIFF_OPT_SET(&revs->pruning, QUICK);
1298         revs->pruning.add_remove = file_add_remove;
1299         revs->pruning.change = file_change;
1300         revs->sort_order = REV_SORT_IN_GRAPH_ORDER;
1301         revs->dense = 1;
1302         revs->prefix = prefix;
1303         revs->max_age = -1;
1304         revs->min_age = -1;
1305         revs->skip_count = -1;
1306         revs->max_count = -1;
1307         revs->max_parents = -1;
1308
1309         revs->commit_format = CMIT_FMT_DEFAULT;
1310
1311         init_grep_defaults();
1312         grep_init(&revs->grep_filter, prefix);
1313         revs->grep_filter.status_only = 1;
1314         revs->grep_filter.regflags = REG_NEWLINE;
1315
1316         diff_setup(&revs->diffopt);
1317         if (prefix && !revs->diffopt.prefix) {
1318                 revs->diffopt.prefix = prefix;
1319                 revs->diffopt.prefix_length = strlen(prefix);
1320         }
1321
1322         revs->notes_opt.use_default_notes = -1;
1323 }
1324
1325 static void add_pending_commit_list(struct rev_info *revs,
1326                                     struct commit_list *commit_list,
1327                                     unsigned int flags)
1328 {
1329         while (commit_list) {
1330                 struct object *object = &commit_list->item->object;
1331                 object->flags |= flags;
1332                 add_pending_object(revs, object, sha1_to_hex(object->sha1));
1333                 commit_list = commit_list->next;
1334         }
1335 }
1336
1337 static void prepare_show_merge(struct rev_info *revs)
1338 {
1339         struct commit_list *bases;
1340         struct commit *head, *other;
1341         unsigned char sha1[20];
1342         const char **prune = NULL;
1343         int i, prune_num = 1; /* counting terminating NULL */
1344
1345         if (get_sha1("HEAD", sha1))
1346                 die("--merge without HEAD?");
1347         head = lookup_commit_or_die(sha1, "HEAD");
1348         if (get_sha1("MERGE_HEAD", sha1))
1349                 die("--merge without MERGE_HEAD?");
1350         other = lookup_commit_or_die(sha1, "MERGE_HEAD");
1351         add_pending_object(revs, &head->object, "HEAD");
1352         add_pending_object(revs, &other->object, "MERGE_HEAD");
1353         bases = get_merge_bases(head, other, 1);
1354         add_rev_cmdline_list(revs, bases, REV_CMD_MERGE_BASE, UNINTERESTING | BOTTOM);
1355         add_pending_commit_list(revs, bases, UNINTERESTING | BOTTOM);
1356         free_commit_list(bases);
1357         head->object.flags |= SYMMETRIC_LEFT;
1358
1359         if (!active_nr)
1360                 read_cache();
1361         for (i = 0; i < active_nr; i++) {
1362                 const struct cache_entry *ce = active_cache[i];
1363                 if (!ce_stage(ce))
1364                         continue;
1365                 if (ce_path_match(ce, &revs->prune_data)) {
1366                         prune_num++;
1367                         prune = xrealloc(prune, sizeof(*prune) * prune_num);
1368                         prune[prune_num-2] = ce->name;
1369                         prune[prune_num-1] = NULL;
1370                 }
1371                 while ((i+1 < active_nr) &&
1372                        ce_same_name(ce, active_cache[i+1]))
1373                         i++;
1374         }
1375         free_pathspec(&revs->prune_data);
1376         init_pathspec(&revs->prune_data, prune);
1377         revs->limited = 1;
1378 }
1379
1380 int 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
1513 struct cmdline_pathspec {
1514         int alloc;
1515         int nr;
1516         const char **path;
1517 };
1518
1519 static 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
1527 static 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
1539 static 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
1568 static 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
1573 static 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
1578 static void add_message_grep(struct rev_info *revs, const char *pattern)
1579 {
1580         add_grep(revs, pattern, GREP_PATTERN_BODY);
1581 }
1582
1583 static 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
1927 void 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
1941 static 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
1946 static 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
1951 static 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  */
2032 int 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                 init_pathspec(&revs->prune_data,
2140                               get_pathspec(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                 diff_tree_setup_paths(revs->prune_data.raw, &revs->pruning);
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                         diff_tree_setup_paths(revs->prune_data.raw, &revs->diffopt);
2179         }
2180         if (revs->combine_merges)
2181                 revs->ignore_merges = 0;
2182         revs->diffopt.abbrev = revs->abbrev;
2183
2184         if (revs->line_level_traverse) {
2185                 revs->limited = 1;
2186                 revs->topo_order = 1;
2187         }
2188
2189         diff_setup_done(&revs->diffopt);
2190
2191         grep_commit_pattern_type(GREP_PATTERN_TYPE_UNSPECIFIED,
2192                                  &revs->grep_filter);
2193         compile_grep_patterns(&revs->grep_filter);
2194
2195         if (revs->reverse && revs->reflog_info)
2196                 die("cannot combine --reverse with --walk-reflogs");
2197         if (revs->rewrite_parents && revs->children.name)
2198                 die("cannot combine --parents and --children");
2199
2200         /*
2201          * Limitations on the graph functionality
2202          */
2203         if (revs->reverse && revs->graph)
2204                 die("cannot combine --reverse with --graph");
2205
2206         if (revs->reflog_info && revs->graph)
2207                 die("cannot combine --walk-reflogs with --graph");
2208         if (!revs->reflog_info && revs->grep_filter.use_reflog_filter)
2209                 die("cannot use --grep-reflog without --walk-reflogs");
2210
2211         return left;
2212 }
2213
2214 static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
2215 {
2216         struct commit_list *l = xcalloc(1, sizeof(*l));
2217
2218         l->item = child;
2219         l->next = add_decoration(&revs->children, &parent->object, l);
2220 }
2221
2222 static int remove_duplicate_parents(struct rev_info *revs, struct commit *commit)
2223 {
2224         struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2225         struct commit_list **pp, *p;
2226         int surviving_parents;
2227
2228         /* Examine existing parents while marking ones we have seen... */
2229         pp = &commit->parents;
2230         surviving_parents = 0;
2231         while ((p = *pp) != NULL) {
2232                 struct commit *parent = p->item;
2233                 if (parent->object.flags & TMP_MARK) {
2234                         *pp = p->next;
2235                         if (ts)
2236                                 compact_treesame(revs, commit, surviving_parents);
2237                         continue;
2238                 }
2239                 parent->object.flags |= TMP_MARK;
2240                 surviving_parents++;
2241                 pp = &p->next;
2242         }
2243         /* clear the temporary mark */
2244         for (p = commit->parents; p; p = p->next) {
2245                 p->item->object.flags &= ~TMP_MARK;
2246         }
2247         /* no update_treesame() - removing duplicates can't affect TREESAME */
2248         return surviving_parents;
2249 }
2250
2251 struct merge_simplify_state {
2252         struct commit *simplified;
2253 };
2254
2255 static struct merge_simplify_state *locate_simplify_state(struct rev_info *revs, struct commit *commit)
2256 {
2257         struct merge_simplify_state *st;
2258
2259         st = lookup_decoration(&revs->merge_simplification, &commit->object);
2260         if (!st) {
2261                 st = xcalloc(1, sizeof(*st));
2262                 add_decoration(&revs->merge_simplification, &commit->object, st);
2263         }
2264         return st;
2265 }
2266
2267 static int mark_redundant_parents(struct rev_info *revs, struct commit *commit)
2268 {
2269         struct commit_list *h = reduce_heads(commit->parents);
2270         int i = 0, marked = 0;
2271         struct commit_list *po, *pn;
2272
2273         /* Want these for sanity-checking only */
2274         int orig_cnt = commit_list_count(commit->parents);
2275         int cnt = commit_list_count(h);
2276
2277         /*
2278          * Not ready to remove items yet, just mark them for now, based
2279          * on the output of reduce_heads(). reduce_heads outputs the reduced
2280          * set in its original order, so this isn't too hard.
2281          */
2282         po = commit->parents;
2283         pn = h;
2284         while (po) {
2285                 if (pn && po->item == pn->item) {
2286                         pn = pn->next;
2287                         i++;
2288                 } else {
2289                         po->item->object.flags |= TMP_MARK;
2290                         marked++;
2291                 }
2292                 po=po->next;
2293         }
2294
2295         if (i != cnt || cnt+marked != orig_cnt)
2296                 die("mark_redundant_parents %d %d %d %d", orig_cnt, cnt, i, marked);
2297
2298         free_commit_list(h);
2299
2300         return marked;
2301 }
2302
2303 static int mark_treesame_root_parents(struct rev_info *revs, struct commit *commit)
2304 {
2305         struct commit_list *p;
2306         int marked = 0;
2307
2308         for (p = commit->parents; p; p = p->next) {
2309                 struct commit *parent = p->item;
2310                 if (!parent->parents && (parent->object.flags & TREESAME)) {
2311                         parent->object.flags |= TMP_MARK;
2312                         marked++;
2313                 }
2314         }
2315
2316         return marked;
2317 }
2318
2319 /*
2320  * Awkward naming - this means one parent we are TREESAME to.
2321  * cf mark_treesame_root_parents: root parents that are TREESAME (to an
2322  * empty tree). Better name suggestions?
2323  */
2324 static int leave_one_treesame_to_parent(struct rev_info *revs, struct commit *commit)
2325 {
2326         struct treesame_state *ts = lookup_decoration(&revs->treesame, &commit->object);
2327         struct commit *unmarked = NULL, *marked = NULL;
2328         struct commit_list *p;
2329         unsigned n;
2330
2331         for (p = commit->parents, n = 0; p; p = p->next, n++) {
2332                 if (ts->treesame[n]) {
2333                         if (p->item->object.flags & TMP_MARK) {
2334                                 if (!marked)
2335                                         marked = p->item;
2336                         } else {
2337                                 if (!unmarked) {
2338                                         unmarked = p->item;
2339                                         break;
2340                                 }
2341                         }
2342                 }
2343         }
2344
2345         /*
2346          * If we are TREESAME to a marked-for-deletion parent, but not to any
2347          * unmarked parents, unmark the first TREESAME parent. This is the
2348          * parent that the default simplify_history==1 scan would have followed,
2349          * and it doesn't make sense to omit that path when asking for a
2350          * simplified full history. Retaining it improves the chances of
2351          * understanding odd missed merges that took an old version of a file.
2352          *
2353          * Example:
2354          *
2355          *   I--------*X       A modified the file, but mainline merge X used
2356          *    \       /        "-s ours", so took the version from I. X is
2357          *     `-*A--'         TREESAME to I and !TREESAME to A.
2358          *
2359          * Default log from X would produce "I". Without this check,
2360          * --full-history --simplify-merges would produce "I-A-X", showing
2361          * the merge commit X and that it changed A, but not making clear that
2362          * it had just taken the I version. With this check, the topology above
2363          * is retained.
2364          *
2365          * Note that it is possible that the simplification chooses a different
2366          * TREESAME parent from the default, in which case this test doesn't
2367          * activate, and we _do_ drop the default parent. Example:
2368          *
2369          *   I------X         A modified the file, but it was reverted in B,
2370          *    \    /          meaning mainline merge X is TREESAME to both
2371          *    *A-*B           parents.
2372          *
2373          * Default log would produce "I" by following the first parent;
2374          * --full-history --simplify-merges will produce "I-A-B". But this is a
2375          * reasonable result - it presents a logical full history leading from
2376          * I to X, and X is not an important merge.
2377          */
2378         if (!unmarked && marked) {
2379                 marked->object.flags &= ~TMP_MARK;
2380                 return 1;
2381         }
2382
2383         return 0;
2384 }
2385
2386 static int remove_marked_parents(struct rev_info *revs, struct commit *commit)
2387 {
2388         struct commit_list **pp, *p;
2389         int nth_parent, removed = 0;
2390
2391         pp = &commit->parents;
2392         nth_parent = 0;
2393         while ((p = *pp) != NULL) {
2394                 struct commit *parent = p->item;
2395                 if (parent->object.flags & TMP_MARK) {
2396                         parent->object.flags &= ~TMP_MARK;
2397                         *pp = p->next;
2398                         free(p);
2399                         removed++;
2400                         compact_treesame(revs, commit, nth_parent);
2401                         continue;
2402                 }
2403                 pp = &p->next;
2404                 nth_parent++;
2405         }
2406
2407         /* Removing parents can only increase TREESAMEness */
2408         if (removed && !(commit->object.flags & TREESAME))
2409                 update_treesame(revs, commit);
2410
2411         return nth_parent;
2412 }
2413
2414 static struct commit_list **simplify_one(struct rev_info *revs, struct commit *commit, struct commit_list **tail)
2415 {
2416         struct commit_list *p;
2417         struct commit *parent;
2418         struct merge_simplify_state *st, *pst;
2419         int cnt;
2420
2421         st = locate_simplify_state(revs, commit);
2422
2423         /*
2424          * Have we handled this one?
2425          */
2426         if (st->simplified)
2427                 return tail;
2428
2429         /*
2430          * An UNINTERESTING commit simplifies to itself, so does a
2431          * root commit.  We do not rewrite parents of such commit
2432          * anyway.
2433          */
2434         if ((commit->object.flags & UNINTERESTING) || !commit->parents) {
2435                 st->simplified = commit;
2436                 return tail;
2437         }
2438
2439         /*
2440          * Do we know what commit all of our parents that matter
2441          * should be rewritten to?  Otherwise we are not ready to
2442          * rewrite this one yet.
2443          */
2444         for (cnt = 0, p = commit->parents; p; p = p->next) {
2445                 pst = locate_simplify_state(revs, p->item);
2446                 if (!pst->simplified) {
2447                         tail = &commit_list_insert(p->item, tail)->next;
2448                         cnt++;
2449                 }
2450                 if (revs->first_parent_only)
2451                         break;
2452         }
2453         if (cnt) {
2454                 tail = &commit_list_insert(commit, tail)->next;
2455                 return tail;
2456         }
2457
2458         /*
2459          * Rewrite our list of parents. Note that this cannot
2460          * affect our TREESAME flags in any way - a commit is
2461          * always TREESAME to its simplification.
2462          */
2463         for (p = commit->parents; p; p = p->next) {
2464                 pst = locate_simplify_state(revs, p->item);
2465                 p->item = pst->simplified;
2466                 if (revs->first_parent_only)
2467                         break;
2468         }
2469
2470         if (revs->first_parent_only)
2471                 cnt = 1;
2472         else
2473                 cnt = remove_duplicate_parents(revs, commit);
2474
2475         /*
2476          * It is possible that we are a merge and one side branch
2477          * does not have any commit that touches the given paths;
2478          * in such a case, the immediate parent from that branch
2479          * will be rewritten to be the merge base.
2480          *
2481          *      o----X          X: the commit we are looking at;
2482          *     /    /           o: a commit that touches the paths;
2483          * ---o----'
2484          *
2485          * Further, a merge of an independent branch that doesn't
2486          * touch the path will reduce to a treesame root parent:
2487          *
2488          *  ----o----X          X: the commit we are looking at;
2489          *          /           o: a commit that touches the paths;
2490          *         r            r: a root commit not touching the paths
2491          *
2492          * Detect and simplify both cases.
2493          */
2494         if (1 < cnt) {
2495                 int marked = mark_redundant_parents(revs, commit);
2496                 marked += mark_treesame_root_parents(revs, commit);
2497                 if (marked)
2498                         marked -= leave_one_treesame_to_parent(revs, commit);
2499                 if (marked)
2500                         cnt = remove_marked_parents(revs, commit);
2501         }
2502
2503         /*
2504          * A commit simplifies to itself if it is a root, if it is
2505          * UNINTERESTING, if it touches the given paths, or if it is a
2506          * merge and its parents don't simplify to one relevant commit
2507          * (the first two cases are already handled at the beginning of
2508          * this function).
2509          *
2510          * Otherwise, it simplifies to what its sole relevant parent
2511          * simplifies to.
2512          */
2513         if (!cnt ||
2514             (commit->object.flags & UNINTERESTING) ||
2515             !(commit->object.flags & TREESAME) ||
2516             (parent = one_relevant_parent(revs, commit->parents)) == NULL)
2517                 st->simplified = commit;
2518         else {
2519                 pst = locate_simplify_state(revs, parent);
2520                 st->simplified = pst->simplified;
2521         }
2522         return tail;
2523 }
2524
2525 static void simplify_merges(struct rev_info *revs)
2526 {
2527         struct commit_list *list, *next;
2528         struct commit_list *yet_to_do, **tail;
2529         struct commit *commit;
2530
2531         if (!revs->prune)
2532                 return;
2533
2534         /* feed the list reversed */
2535         yet_to_do = NULL;
2536         for (list = revs->commits; list; list = next) {
2537                 commit = list->item;
2538                 next = list->next;
2539                 /*
2540                  * Do not free(list) here yet; the original list
2541                  * is used later in this function.
2542                  */
2543                 commit_list_insert(commit, &yet_to_do);
2544         }
2545         while (yet_to_do) {
2546                 list = yet_to_do;
2547                 yet_to_do = NULL;
2548                 tail = &yet_to_do;
2549                 while (list) {
2550                         commit = list->item;
2551                         next = list->next;
2552                         free(list);
2553                         list = next;
2554                         tail = simplify_one(revs, commit, tail);
2555                 }
2556         }
2557
2558         /* clean up the result, removing the simplified ones */
2559         list = revs->commits;
2560         revs->commits = NULL;
2561         tail = &revs->commits;
2562         while (list) {
2563                 struct merge_simplify_state *st;
2564
2565                 commit = list->item;
2566                 next = list->next;
2567                 free(list);
2568                 list = next;
2569                 st = locate_simplify_state(revs, commit);
2570                 if (st->simplified == commit)
2571                         tail = &commit_list_insert(commit, tail)->next;
2572         }
2573 }
2574
2575 static void set_children(struct rev_info *revs)
2576 {
2577         struct commit_list *l;
2578         for (l = revs->commits; l; l = l->next) {
2579                 struct commit *commit = l->item;
2580                 struct commit_list *p;
2581
2582                 for (p = commit->parents; p; p = p->next)
2583                         add_child(revs, p->item, commit);
2584         }
2585 }
2586
2587 void reset_revision_walk(void)
2588 {
2589         clear_object_flags(SEEN | ADDED | SHOWN);
2590 }
2591
2592 int prepare_revision_walk(struct rev_info *revs)
2593 {
2594         int nr = revs->pending.nr;
2595         struct object_array_entry *e, *list;
2596         struct commit_list **next = &revs->commits;
2597
2598         e = list = revs->pending.objects;
2599         revs->pending.nr = 0;
2600         revs->pending.alloc = 0;
2601         revs->pending.objects = NULL;
2602         while (--nr >= 0) {
2603                 struct commit *commit = handle_commit(revs, e->item, e->name);
2604                 if (commit) {
2605                         if (!(commit->object.flags & SEEN)) {
2606                                 commit->object.flags |= SEEN;
2607                                 next = commit_list_append(commit, next);
2608                         }
2609                 }
2610                 e++;
2611         }
2612         if (!revs->leak_pending)
2613                 free(list);
2614
2615         /* Signal whether we need per-parent treesame decoration */
2616         if (revs->simplify_merges ||
2617             (revs->limited && limiting_can_increase_treesame(revs)))
2618                 revs->treesame.name = "treesame";
2619
2620         if (revs->no_walk != REVISION_WALK_NO_WALK_UNSORTED)
2621                 commit_list_sort_by_date(&revs->commits);
2622         if (revs->no_walk)
2623                 return 0;
2624         if (revs->limited)
2625                 if (limit_list(revs) < 0)
2626                         return -1;
2627         if (revs->topo_order)
2628                 sort_in_topological_order(&revs->commits, revs->sort_order);
2629         if (revs->line_level_traverse)
2630                 line_log_filter(revs);
2631         if (revs->simplify_merges)
2632                 simplify_merges(revs);
2633         if (revs->children.name)
2634                 set_children(revs);
2635         return 0;
2636 }
2637
2638 static enum rewrite_result rewrite_one(struct rev_info *revs, struct commit **pp)
2639 {
2640         struct commit_list *cache = NULL;
2641
2642         for (;;) {
2643                 struct commit *p = *pp;
2644                 if (!revs->limited)
2645                         if (add_parents_to_list(revs, p, &revs->commits, &cache) < 0)
2646                                 return rewrite_one_error;
2647                 if (p->object.flags & UNINTERESTING)
2648                         return rewrite_one_ok;
2649                 if (!(p->object.flags & TREESAME))
2650                         return rewrite_one_ok;
2651                 if (!p->parents)
2652                         return rewrite_one_noparents;
2653                 if ((p = one_relevant_parent(revs, p->parents)) == NULL)
2654                         return rewrite_one_ok;
2655                 *pp = p;
2656         }
2657 }
2658
2659 int rewrite_parents(struct rev_info *revs, struct commit *commit,
2660         rewrite_parent_fn_t rewrite_parent)
2661 {
2662         struct commit_list **pp = &commit->parents;
2663         while (*pp) {
2664                 struct commit_list *parent = *pp;
2665                 switch (rewrite_parent(revs, &parent->item)) {
2666                 case rewrite_one_ok:
2667                         break;
2668                 case rewrite_one_noparents:
2669                         *pp = parent->next;
2670                         continue;
2671                 case rewrite_one_error:
2672                         return -1;
2673                 }
2674                 pp = &parent->next;
2675         }
2676         remove_duplicate_parents(revs, commit);
2677         return 0;
2678 }
2679
2680 static int commit_rewrite_person(struct strbuf *buf, const char *what, struct string_list *mailmap)
2681 {
2682         char *person, *endp;
2683         size_t len, namelen, maillen;
2684         const char *name;
2685         const char *mail;
2686         struct ident_split ident;
2687
2688         person = strstr(buf->buf, what);
2689         if (!person)
2690                 return 0;
2691
2692         person += strlen(what);
2693         endp = strchr(person, '\n');
2694         if (!endp)
2695                 return 0;
2696
2697         len = endp - person;
2698
2699         if (split_ident_line(&ident, person, len))
2700                 return 0;
2701
2702         mail = ident.mail_begin;
2703         maillen = ident.mail_end - ident.mail_begin;
2704         name = ident.name_begin;
2705         namelen = ident.name_end - ident.name_begin;
2706
2707         if (map_user(mailmap, &mail, &maillen, &name, &namelen)) {
2708                 struct strbuf namemail = STRBUF_INIT;
2709
2710                 strbuf_addf(&namemail, "%.*s <%.*s>",
2711                             (int)namelen, name, (int)maillen, mail);
2712
2713                 strbuf_splice(buf, ident.name_begin - buf->buf,
2714                               ident.mail_end - ident.name_begin + 1,
2715                               namemail.buf, namemail.len);
2716
2717                 strbuf_release(&namemail);
2718
2719                 return 1;
2720         }
2721
2722         return 0;
2723 }
2724
2725 static int commit_match(struct commit *commit, struct rev_info *opt)
2726 {
2727         int retval;
2728         const char *encoding;
2729         char *message;
2730         struct strbuf buf = STRBUF_INIT;
2731
2732         if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
2733                 return 1;
2734
2735         /* Prepend "fake" headers as needed */
2736         if (opt->grep_filter.use_reflog_filter) {
2737                 strbuf_addstr(&buf, "reflog ");
2738                 get_reflog_message(&buf, opt->reflog_info);
2739                 strbuf_addch(&buf, '\n');
2740         }
2741
2742         /*
2743          * We grep in the user's output encoding, under the assumption that it
2744          * is the encoding they are most likely to write their grep pattern
2745          * for. In addition, it means we will match the "notes" encoding below,
2746          * so we will not end up with a buffer that has two different encodings
2747          * in it.
2748          */
2749         encoding = get_log_output_encoding();
2750         message = logmsg_reencode(commit, NULL, encoding);
2751
2752         /* Copy the commit to temporary if we are using "fake" headers */
2753         if (buf.len)
2754                 strbuf_addstr(&buf, message);
2755
2756         if (opt->grep_filter.header_list && opt->mailmap) {
2757                 if (!buf.len)
2758                         strbuf_addstr(&buf, message);
2759
2760                 commit_rewrite_person(&buf, "\nauthor ", opt->mailmap);
2761                 commit_rewrite_person(&buf, "\ncommitter ", opt->mailmap);
2762         }
2763
2764         /* Append "fake" message parts as needed */
2765         if (opt->show_notes) {
2766                 if (!buf.len)
2767                         strbuf_addstr(&buf, message);
2768                 format_display_notes(commit->object.sha1, &buf, encoding, 1);
2769         }
2770
2771         /* Find either in the original commit message, or in the temporary */
2772         if (buf.len)
2773                 retval = grep_buffer(&opt->grep_filter, buf.buf, buf.len);
2774         else
2775                 retval = grep_buffer(&opt->grep_filter,
2776                                      message, strlen(message));
2777         strbuf_release(&buf);
2778         logmsg_free(message, commit);
2779         return retval;
2780 }
2781
2782 static inline int want_ancestry(const struct rev_info *revs)
2783 {
2784         return (revs->rewrite_parents || revs->children.name);
2785 }
2786
2787 enum commit_action get_commit_action(struct rev_info *revs, struct commit *commit)
2788 {
2789         if (commit->object.flags & SHOWN)
2790                 return commit_ignore;
2791         if (revs->unpacked && has_sha1_pack(commit->object.sha1))
2792                 return commit_ignore;
2793         if (revs->show_all)
2794                 return commit_show;
2795         if (commit->object.flags & UNINTERESTING)
2796                 return commit_ignore;
2797         if (revs->min_age != -1 && (commit->date > revs->min_age))
2798                 return commit_ignore;
2799         if (revs->min_parents || (revs->max_parents >= 0)) {
2800                 int n = commit_list_count(commit->parents);
2801                 if ((n < revs->min_parents) ||
2802                     ((revs->max_parents >= 0) && (n > revs->max_parents)))
2803                         return commit_ignore;
2804         }
2805         if (!commit_match(commit, revs))
2806                 return commit_ignore;
2807         if (revs->prune && revs->dense) {
2808                 /* Commit without changes? */
2809                 if (commit->object.flags & TREESAME) {
2810                         int n;
2811                         struct commit_list *p;
2812                         /* drop merges unless we want parenthood */
2813                         if (!want_ancestry(revs))
2814                                 return commit_ignore;
2815                         /*
2816                          * If we want ancestry, then need to keep any merges
2817                          * between relevant commits to tie together topology.
2818                          * For consistency with TREESAME and simplification
2819                          * use "relevant" here rather than just INTERESTING,
2820                          * to treat bottom commit(s) as part of the topology.
2821                          */
2822                         for (n = 0, p = commit->parents; p; p = p->next)
2823                                 if (relevant_commit(p->item))
2824                                         if (++n >= 2)
2825                                                 return commit_show;
2826                         return commit_ignore;
2827                 }
2828         }
2829         return commit_show;
2830 }
2831
2832 enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
2833 {
2834         enum commit_action action = get_commit_action(revs, commit);
2835
2836         if (action == commit_show &&
2837             !revs->show_all &&
2838             revs->prune && revs->dense && want_ancestry(revs)) {
2839                 /*
2840                  * --full-diff on simplified parents is no good: it
2841                  * will show spurious changes from the commits that
2842                  * were elided.  So we save the parents on the side
2843                  * when --full-diff is in effect.
2844                  */
2845                 if (revs->full_diff)
2846                         save_parents(revs, commit);
2847                 if (rewrite_parents(revs, commit, rewrite_one) < 0)
2848                         return commit_error;
2849         }
2850         return action;
2851 }
2852
2853 static struct commit *get_revision_1(struct rev_info *revs)
2854 {
2855         if (!revs->commits)
2856                 return NULL;
2857
2858         do {
2859                 struct commit_list *entry = revs->commits;
2860                 struct commit *commit = entry->item;
2861
2862                 revs->commits = entry->next;
2863                 free(entry);
2864
2865                 if (revs->reflog_info) {
2866                         save_parents(revs, commit);
2867                         fake_reflog_parent(revs->reflog_info, commit);
2868                         commit->object.flags &= ~(ADDED | SEEN | SHOWN);
2869                 }
2870
2871                 /*
2872                  * If we haven't done the list limiting, we need to look at
2873                  * the parents here. We also need to do the date-based limiting
2874                  * that we'd otherwise have done in limit_list().
2875                  */
2876                 if (!revs->limited) {
2877                         if (revs->max_age != -1 &&
2878                             (commit->date < revs->max_age))
2879                                 continue;
2880                         if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0)
2881                                 die("Failed to traverse parents of commit %s",
2882                                     sha1_to_hex(commit->object.sha1));
2883                 }
2884
2885                 switch (simplify_commit(revs, commit)) {
2886                 case commit_ignore:
2887                         continue;
2888                 case commit_error:
2889                         die("Failed to simplify parents of commit %s",
2890                             sha1_to_hex(commit->object.sha1));
2891                 default:
2892                         return commit;
2893                 }
2894         } while (revs->commits);
2895         return NULL;
2896 }
2897
2898 /*
2899  * Return true for entries that have not yet been shown.  (This is an
2900  * object_array_each_func_t.)
2901  */
2902 static int entry_unshown(struct object_array_entry *entry, void *cb_data_unused)
2903 {
2904         return !(entry->item->flags & SHOWN);
2905 }
2906
2907 /*
2908  * If array is on the verge of a realloc, garbage-collect any entries
2909  * that have already been shown to try to free up some space.
2910  */
2911 static void gc_boundary(struct object_array *array)
2912 {
2913         if (array->nr == array->alloc)
2914                 object_array_filter(array, entry_unshown, NULL);
2915 }
2916
2917 static void create_boundary_commit_list(struct rev_info *revs)
2918 {
2919         unsigned i;
2920         struct commit *c;
2921         struct object_array *array = &revs->boundary_commits;
2922         struct object_array_entry *objects = array->objects;
2923
2924         /*
2925          * If revs->commits is non-NULL at this point, an error occurred in
2926          * get_revision_1().  Ignore the error and continue printing the
2927          * boundary commits anyway.  (This is what the code has always
2928          * done.)
2929          */
2930         if (revs->commits) {
2931                 free_commit_list(revs->commits);
2932                 revs->commits = NULL;
2933         }
2934
2935         /*
2936          * Put all of the actual boundary commits from revs->boundary_commits
2937          * into revs->commits
2938          */
2939         for (i = 0; i < array->nr; i++) {
2940                 c = (struct commit *)(objects[i].item);
2941                 if (!c)
2942                         continue;
2943                 if (!(c->object.flags & CHILD_SHOWN))
2944                         continue;
2945                 if (c->object.flags & (SHOWN | BOUNDARY))
2946                         continue;
2947                 c->object.flags |= BOUNDARY;
2948                 commit_list_insert(c, &revs->commits);
2949         }
2950
2951         /*
2952          * If revs->topo_order is set, sort the boundary commits
2953          * in topological order
2954          */
2955         sort_in_topological_order(&revs->commits, revs->sort_order);
2956 }
2957
2958 static struct commit *get_revision_internal(struct rev_info *revs)
2959 {
2960         struct commit *c = NULL;
2961         struct commit_list *l;
2962
2963         if (revs->boundary == 2) {
2964                 /*
2965                  * All of the normal commits have already been returned,
2966                  * and we are now returning boundary commits.
2967                  * create_boundary_commit_list() has populated
2968                  * revs->commits with the remaining commits to return.
2969                  */
2970                 c = pop_commit(&revs->commits);
2971                 if (c)
2972                         c->object.flags |= SHOWN;
2973                 return c;
2974         }
2975
2976         /*
2977          * If our max_count counter has reached zero, then we are done. We
2978          * don't simply return NULL because we still might need to show
2979          * boundary commits. But we want to avoid calling get_revision_1, which
2980          * might do a considerable amount of work finding the next commit only
2981          * for us to throw it away.
2982          *
2983          * If it is non-zero, then either we don't have a max_count at all
2984          * (-1), or it is still counting, in which case we decrement.
2985          */
2986         if (revs->max_count) {
2987                 c = get_revision_1(revs);
2988                 if (c) {
2989                         while (0 < revs->skip_count) {
2990                                 revs->skip_count--;
2991                                 c = get_revision_1(revs);
2992                                 if (!c)
2993                                         break;
2994                         }
2995                 }
2996
2997                 if (revs->max_count > 0)
2998                         revs->max_count--;
2999         }
3000
3001         if (c)
3002                 c->object.flags |= SHOWN;
3003
3004         if (!revs->boundary) {
3005                 return c;
3006         }
3007
3008         if (!c) {
3009                 /*
3010                  * get_revision_1() runs out the commits, and
3011                  * we are done computing the boundaries.
3012                  * switch to boundary commits output mode.
3013                  */
3014                 revs->boundary = 2;
3015
3016                 /*
3017                  * Update revs->commits to contain the list of
3018                  * boundary commits.
3019                  */
3020                 create_boundary_commit_list(revs);
3021
3022                 return get_revision_internal(revs);
3023         }
3024
3025         /*
3026          * boundary commits are the commits that are parents of the
3027          * ones we got from get_revision_1() but they themselves are
3028          * not returned from get_revision_1().  Before returning
3029          * 'c', we need to mark its parents that they could be boundaries.
3030          */
3031
3032         for (l = c->parents; l; l = l->next) {
3033                 struct object *p;
3034                 p = &(l->item->object);
3035                 if (p->flags & (CHILD_SHOWN | SHOWN))
3036                         continue;
3037                 p->flags |= CHILD_SHOWN;
3038                 gc_boundary(&revs->boundary_commits);
3039                 add_object_array(p, NULL, &revs->boundary_commits);
3040         }
3041
3042         return c;
3043 }
3044
3045 struct commit *get_revision(struct rev_info *revs)
3046 {
3047         struct commit *c;
3048         struct commit_list *reversed;
3049
3050         if (revs->reverse) {
3051                 reversed = NULL;
3052                 while ((c = get_revision_internal(revs))) {
3053                         commit_list_insert(c, &reversed);
3054                 }
3055                 revs->commits = reversed;
3056                 revs->reverse = 0;
3057                 revs->reverse_output_stage = 1;
3058         }
3059
3060         if (revs->reverse_output_stage)
3061                 return pop_commit(&revs->commits);
3062
3063         c = get_revision_internal(revs);
3064         if (c && revs->graph)
3065                 graph_update(revs->graph, c);
3066         if (!c)
3067                 free_saved_parents(revs);
3068         return c;
3069 }
3070
3071 char *get_revision_mark(const struct rev_info *revs, const struct commit *commit)
3072 {
3073         if (commit->object.flags & BOUNDARY)
3074                 return "-";
3075         else if (commit->object.flags & UNINTERESTING)
3076                 return "^";
3077         else if (commit->object.flags & PATCHSAME)
3078                 return "=";
3079         else if (!revs || revs->left_right) {
3080                 if (commit->object.flags & SYMMETRIC_LEFT)
3081                         return "<";
3082                 else
3083                         return ">";
3084         } else if (revs->graph)
3085                 return "*";
3086         else if (revs->cherry_mark)
3087                 return "+";
3088         return "";
3089 }
3090
3091 void put_revision_mark(const struct rev_info *revs, const struct commit *commit)
3092 {
3093         char *mark = get_revision_mark(revs, commit);
3094         if (!strlen(mark))
3095                 return;
3096         fputs(mark, stdout);
3097         putchar(' ');
3098 }
3099
3100 define_commit_slab(saved_parents, struct commit_list *);
3101
3102 #define EMPTY_PARENT_LIST ((struct commit_list *)-1)
3103
3104 void save_parents(struct rev_info *revs, struct commit *commit)
3105 {
3106         struct commit_list **pp;
3107
3108         if (!revs->saved_parents_slab) {
3109                 revs->saved_parents_slab = xmalloc(sizeof(struct saved_parents));
3110                 init_saved_parents(revs->saved_parents_slab);
3111         }
3112
3113         pp = saved_parents_at(revs->saved_parents_slab, commit);
3114
3115         /*
3116          * When walking with reflogs, we may visit the same commit
3117          * several times: once for each appearance in the reflog.
3118          *
3119          * In this case, save_parents() will be called multiple times.
3120          * We want to keep only the first set of parents.  We need to
3121          * store a sentinel value for an empty (i.e., NULL) parent
3122          * list to distinguish it from a not-yet-saved list, however.
3123          */
3124         if (*pp)
3125                 return;
3126         if (commit->parents)
3127                 *pp = copy_commit_list(commit->parents);
3128         else
3129                 *pp = EMPTY_PARENT_LIST;
3130 }
3131
3132 struct commit_list *get_saved_parents(struct rev_info *revs, const struct commit *commit)
3133 {
3134         struct commit_list *parents;
3135
3136         if (!revs->saved_parents_slab)
3137                 return commit->parents;
3138
3139         parents = *saved_parents_at(revs->saved_parents_slab, commit);
3140         if (parents == EMPTY_PARENT_LIST)
3141                 return NULL;
3142         return parents;
3143 }
3144
3145 void free_saved_parents(struct rev_info *revs)
3146 {
3147         if (revs->saved_parents_slab)
3148                 clear_saved_parents(revs->saved_parents_slab);
3149 }