diff-lib.c

   1 /*
   2  * Copyright (C) 2005 Junio C Hamano
   3  */
   4 #include "cache.h"
   5 #include "quote.h"
   6 #include "commit.h"
   7 #include "diff.h"
   8 #include "diffcore.h"
   9 #include "gettext.h"
  10 #include "hex.h"
  11 #include "object-name.h"
  12 #include "revision.h"
  13 #include "cache-tree.h"
  14 #include "unpack-trees.h"
  15 #include "refs.h"
  16 #include "submodule.h"
  17 #include "symlinks.h"
  18 #include "trace.h"
  19 #include "dir.h"
  20 #include "fsmonitor.h"
  21 #include "commit-reach.h"
  22
  23 /*
  24  * diff-files
  25  */
  26
  27 /*
  28  * Has the work tree entity been removed?
  29  *
  30  * Return 1 if it was removed from the work tree, 0 if an entity to be
  31  * compared with the cache entry ce still exists (the latter includes
  32  * the case where a directory that is not a submodule repository
  33  * exists for ce that is a submodule -- it is a submodule that is not
  34  * checked out).  Return negative for an error.
  35  */
  36 static int check_removed(const struct index_state *istate, const struct cache_entry *ce, struct stat *st)
  37 {
  38         assert(is_fsmonitor_refreshed(istate));
  39         if (!(ce->ce_flags & CE_FSMONITOR_VALID) && lstat(ce->name, st) < 0) {
  40                 if (!is_missing_file_error(errno))
  41                         return -1;
  42                 return 1;
  43         }
  44         if (has_symlink_leading_path(ce->name, ce_namelen(ce)))
  45                 return 1;
  46         if (S_ISDIR(st->st_mode)) {
  47                 struct object_id sub;
  48
  49                 /*
  50                  * If ce is already a gitlink, we can have a plain
  51                  * directory (i.e. the submodule is not checked out),
  52                  * or a checked out submodule.  Either case this is not
  53                  * a case where something was removed from the work tree,
  54                  * so we will return 0.
  55                  *
  56                  * Otherwise, if the directory is not a submodule
  57                  * repository, that means ce which was a blob turned into
  58                  * a directory --- the blob was removed!
  59                  */
  60                 if (!S_ISGITLINK(ce->ce_mode) &&
  61                     resolve_gitlink_ref(ce->name, "HEAD", &sub))
  62                         return 1;
  63         }
  64         return 0;
  65 }
  66
  67 /*
  68  * Has a file changed or has a submodule new commits or a dirty work tree?
  69  *
  70  * Return 1 when changes are detected, 0 otherwise. If the DIRTY_SUBMODULES
  71  * option is set, the caller does not only want to know if a submodule is
  72  * modified at all but wants to know all the conditions that are met (new
  73  * commits, untracked content and/or modified content).
  74  */
  75 static int match_stat_with_submodule(struct diff_options *diffopt,
  76                                      const struct cache_entry *ce,
  77                                      struct stat *st, unsigned ce_option,
  78                                      unsigned *dirty_submodule)
  79 {
  80         int changed = ie_match_stat(diffopt->repo->index, ce, st, ce_option);
  81         if (S_ISGITLINK(ce->ce_mode)) {
  82                 struct diff_flags orig_flags = diffopt->flags;
  83                 if (!diffopt->flags.override_submodule_config)
  84                         set_diffopt_flags_from_submodule_config(diffopt, ce->name);
  85                 if (diffopt->flags.ignore_submodules)
  86                         changed = 0;
  87                 else if (!diffopt->flags.ignore_dirty_submodules &&
  88                          (!changed || diffopt->flags.dirty_submodules))
  89                         *dirty_submodule = is_submodule_modified(ce->name,
  90                                                                  diffopt->flags.ignore_untracked_in_submodules);
  91                 diffopt->flags = orig_flags;
  92         }
  93         return changed;
  94 }
  95
  96 int run_diff_files(struct rev_info *revs, unsigned int option)
  97 {
  98         int entries, i;
  99         int diff_unmerged_stage = revs->max_count;
 100         unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
 101                               ? CE_MATCH_RACY_IS_DIRTY : 0);
 102         uint64_t start = getnanotime();
 103         struct index_state *istate = revs->diffopt.repo->index;
 104
 105         diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
 106
 107         refresh_fsmonitor(istate);
 108
 109         if (diff_unmerged_stage < 0)
 110                 diff_unmerged_stage = 2;
 111         entries = istate->cache_nr;
 112         for (i = 0; i < entries; i++) {
 113                 unsigned int oldmode, newmode;
 114                 struct cache_entry *ce = istate->cache[i];
 115                 int changed;
 116                 unsigned dirty_submodule = 0;
 117                 const struct object_id *old_oid, *new_oid;
 118
 119                 if (diff_can_quit_early(&revs->diffopt))
 120                         break;
 121
 122                 if (!ce_path_match(istate, ce, &revs->prune_data, NULL))
 123                         continue;
 124
 125                 if (revs->diffopt.prefix &&
 126                     strncmp(ce->name, revs->diffopt.prefix, revs->diffopt.prefix_length))
 127                         continue;
 128
 129                 if (ce_stage(ce)) {
 130                         struct combine_diff_path *dpath;
 131                         struct diff_filepair *pair;
 132                         unsigned int wt_mode = 0;
 133                         int num_compare_stages = 0;
 134                         size_t path_len;
 135                         struct stat st;
 136
 137                         path_len = ce_namelen(ce);
 138
 139                         dpath = xmalloc(combine_diff_path_size(5, path_len));
 140                         dpath->path = (char *) &(dpath->parent[5]);
 141
 142                         dpath->next = NULL;
 143                         memcpy(dpath->path, ce->name, path_len);
 144                         dpath->path[path_len] = '\0';
 145                         oidclr(&dpath->oid);
 146                         memset(&(dpath->parent[0]), 0,
 147                                sizeof(struct combine_diff_parent)*5);
 148
 149                         changed = check_removed(istate, ce, &st);
 150                         if (!changed)
 151                                 wt_mode = ce_mode_from_stat(ce, st.st_mode);
 152                         else {
 153                                 if (changed < 0) {
 154                                         perror(ce->name);
 155                                         continue;
 156                                 }
 157                                 wt_mode = 0;
 158                         }
 159                         dpath->mode = wt_mode;
 160
 161                         while (i < entries) {
 162                                 struct cache_entry *nce = istate->cache[i];
 163                                 int stage;
 164
 165                                 if (strcmp(ce->name, nce->name))
 166                                         break;
 167
 168                                 /* Stage #2 (ours) is the first parent,
 169                                  * stage #3 (theirs) is the second.
 170                                  */
 171                                 stage = ce_stage(nce);
 172                                 if (2 <= stage) {
 173                                         int mode = nce->ce_mode;
 174                                         num_compare_stages++;
 175                                         oidcpy(&dpath->parent[stage - 2].oid,
 176                                                &nce->oid);
 177                                         dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
 178                                         dpath->parent[stage-2].status =
 179                                                 DIFF_STATUS_MODIFIED;
 180                                 }
 181
 182                                 /* diff against the proper unmerged stage */
 183                                 if (stage == diff_unmerged_stage)
 184                                         ce = nce;
 185                                 i++;
 186                         }
 187                         /*
 188                          * Compensate for loop update
 189                          */
 190                         i--;
 191
 192                         if (revs->combine_merges && num_compare_stages == 2) {
 193                                 show_combined_diff(dpath, 2, revs);
 194                                 free(dpath);
 195                                 continue;
 196                         }
 197                         FREE_AND_NULL(dpath);
 198
 199                         /*
 200                          * Show the diff for the 'ce' if we found the one
 201                          * from the desired stage.
 202                          */
 203                         pair = diff_unmerge(&revs->diffopt, ce->name);
 204                         if (wt_mode)
 205                                 pair->two->mode = wt_mode;
 206                         if (ce_stage(ce) != diff_unmerged_stage)
 207                                 continue;
 208                 }
 209
 210                 if (ce_uptodate(ce) || ce_skip_worktree(ce))
 211                         continue;
 212
 213                 /*
 214                  * When CE_VALID is set (via "update-index --assume-unchanged"
 215                  * or via adding paths while core.ignorestat is set to true),
 216                  * the user has promised that the working tree file for that
 217                  * path will not be modified.  When CE_FSMONITOR_VALID is true,
 218                  * the fsmonitor knows that the path hasn't been modified since
 219                  * we refreshed the cached stat information.  In either case,
 220                  * we do not have to stat to see if the path has been removed
 221                  * or modified.
 222                  */
 223                 if (ce->ce_flags & (CE_VALID | CE_FSMONITOR_VALID)) {
 224                         changed = 0;
 225                         newmode = ce->ce_mode;
 226                 } else {
 227                         struct stat st;
 228
 229                         changed = check_removed(istate, ce, &st);
 230                         if (changed) {
 231                                 if (changed < 0) {
 232                                         perror(ce->name);
 233                                         continue;
 234                                 }
 235                                 diff_addremove(&revs->diffopt, '-', ce->ce_mode,
 236                                                &ce->oid,
 237                                                !is_null_oid(&ce->oid),
 238                                                ce->name, 0);
 239                                 continue;
 240                         } else if (revs->diffopt.ita_invisible_in_index &&
 241                                    ce_intent_to_add(ce)) {
 242                                 newmode = ce_mode_from_stat(ce, st.st_mode);
 243                                 diff_addremove(&revs->diffopt, '+', newmode,
 244                                                null_oid(), 0, ce->name, 0);
 245                                 continue;
 246                         }
 247
 248                         changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
 249                                                             ce_option, &dirty_submodule);
 250                         newmode = ce_mode_from_stat(ce, st.st_mode);
 251                 }
 252
 253                 if (!changed && !dirty_submodule) {
 254                         ce_mark_uptodate(ce);
 255                         mark_fsmonitor_valid(istate, ce);
 256                         if (!revs->diffopt.flags.find_copies_harder)
 257                                 continue;
 258                 }
 259                 oldmode = ce->ce_mode;
 260                 old_oid = &ce->oid;
 261                 new_oid = changed ? null_oid() : &ce->oid;
 262                 diff_change(&revs->diffopt, oldmode, newmode,
 263                             old_oid, new_oid,
 264                             !is_null_oid(old_oid),
 265                             !is_null_oid(new_oid),
 266                             ce->name, 0, dirty_submodule);
 267
 268         }
 269         diffcore_std(&revs->diffopt);
 270         diff_flush(&revs->diffopt);
 271         trace_performance_since(start, "diff-files");
 272         return 0;
 273 }
 274
 275 /*
 276  * diff-index
 277  */
 278
 279 /* A file entry went away or appeared */
 280 static void diff_index_show_file(struct rev_info *revs,
 281                                  const char *prefix,
 282                                  const struct cache_entry *ce,
 283                                  const struct object_id *oid, int oid_valid,
 284                                  unsigned int mode,
 285                                  unsigned dirty_submodule)
 286 {
 287         diff_addremove(&revs->diffopt, prefix[0], mode,
 288                        oid, oid_valid, ce->name, dirty_submodule);
 289 }
 290
 291 static int get_stat_data(const struct index_state *istate,
 292                          const struct cache_entry *ce,
 293                          const struct object_id **oidp,
 294                          unsigned int *modep,
 295                          int cached, int match_missing,
 296                          unsigned *dirty_submodule, struct diff_options *diffopt)
 297 {
 298         const struct object_id *oid = &ce->oid;
 299         unsigned int mode = ce->ce_mode;
 300
 301         if (!cached && !ce_uptodate(ce)) {
 302                 int changed;
 303                 struct stat st;
 304                 changed = check_removed(istate, ce, &st);
 305                 if (changed < 0)
 306                         return -1;
 307                 else if (changed) {
 308                         if (match_missing) {
 309                                 *oidp = oid;
 310                                 *modep = mode;
 311                                 return 0;
 312                         }
 313                         return -1;
 314                 }
 315                 changed = match_stat_with_submodule(diffopt, ce, &st,
 316                                                     0, dirty_submodule);
 317                 if (changed) {
 318                         mode = ce_mode_from_stat(ce, st.st_mode);
 319                         oid = null_oid();
 320                 }
 321         }
 322
 323         *oidp = oid;
 324         *modep = mode;
 325         return 0;
 326 }
 327
 328 static void show_new_file(struct rev_info *revs,
 329                           const struct cache_entry *new_file,
 330                           int cached, int match_missing)
 331 {
 332         const struct object_id *oid;
 333         unsigned int mode;
 334         unsigned dirty_submodule = 0;
 335         struct index_state *istate = revs->diffopt.repo->index;
 336
 337         if (new_file && S_ISSPARSEDIR(new_file->ce_mode)) {
 338                 diff_tree_oid(NULL, &new_file->oid, new_file->name, &revs->diffopt);
 339                 return;
 340         }
 341
 342         /*
 343          * New file in the index: it might actually be different in
 344          * the working tree.
 345          */
 346         if (get_stat_data(istate, new_file, &oid, &mode, cached, match_missing,
 347             &dirty_submodule, &revs->diffopt) < 0)
 348                 return;
 349
 350         diff_index_show_file(revs, "+", new_file, oid, !is_null_oid(oid), mode, dirty_submodule);
 351 }
 352
 353 static int show_modified(struct rev_info *revs,
 354                          const struct cache_entry *old_entry,
 355                          const struct cache_entry *new_entry,
 356                          int report_missing,
 357                          int cached, int match_missing)
 358 {
 359         unsigned int mode, oldmode;
 360         const struct object_id *oid;
 361         unsigned dirty_submodule = 0;
 362         struct index_state *istate = revs->diffopt.repo->index;
 363
 364         assert(S_ISSPARSEDIR(old_entry->ce_mode) ==
 365                S_ISSPARSEDIR(new_entry->ce_mode));
 366
 367         /*
 368          * If both are sparse directory entries, then expand the
 369          * modifications to the file level. If only one was a sparse
 370          * directory, then they appear as an add and delete instead of
 371          * a modification.
 372          */
 373         if (S_ISSPARSEDIR(new_entry->ce_mode)) {
 374                 diff_tree_oid(&old_entry->oid, &new_entry->oid, new_entry->name, &revs->diffopt);
 375                 return 0;
 376         }
 377
 378         if (get_stat_data(istate, new_entry, &oid, &mode, cached, match_missing,
 379                           &dirty_submodule, &revs->diffopt) < 0) {
 380                 if (report_missing)
 381                         diff_index_show_file(revs, "-", old_entry,
 382                                              &old_entry->oid, 1, old_entry->ce_mode,
 383                                              0);
 384                 return -1;
 385         }
 386
 387         if (revs->combine_merges && !cached &&
 388             (!oideq(oid, &old_entry->oid) || !oideq(&old_entry->oid, &new_entry->oid))) {
 389                 struct combine_diff_path *p;
 390                 int pathlen = ce_namelen(new_entry);
 391
 392                 p = xmalloc(combine_diff_path_size(2, pathlen));
 393                 p->path = (char *) &p->parent[2];
 394                 p->next = NULL;
 395                 memcpy(p->path, new_entry->name, pathlen);
 396                 p->path[pathlen] = 0;
 397                 p->mode = mode;
 398                 oidclr(&p->oid);
 399                 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
 400                 p->parent[0].status = DIFF_STATUS_MODIFIED;
 401                 p->parent[0].mode = new_entry->ce_mode;
 402                 oidcpy(&p->parent[0].oid, &new_entry->oid);
 403                 p->parent[1].status = DIFF_STATUS_MODIFIED;
 404                 p->parent[1].mode = old_entry->ce_mode;
 405                 oidcpy(&p->parent[1].oid, &old_entry->oid);
 406                 show_combined_diff(p, 2, revs);
 407                 free(p);
 408                 return 0;
 409         }
 410
 411         oldmode = old_entry->ce_mode;
 412         if (mode == oldmode && oideq(oid, &old_entry->oid) && !dirty_submodule &&
 413             !revs->diffopt.flags.find_copies_harder)
 414                 return 0;
 415
 416         diff_change(&revs->diffopt, oldmode, mode,
 417                     &old_entry->oid, oid, 1, !is_null_oid(oid),
 418                     old_entry->name, 0, dirty_submodule);
 419         return 0;
 420 }
 421
 422 /*
 423  * This gets a mix of an existing index and a tree, one pathname entry
 424  * at a time. The index entry may be a single stage-0 one, but it could
 425  * also be multiple unmerged entries (in which case idx_pos/idx_nr will
 426  * give you the position and number of entries in the index).
 427  */
 428 static void do_oneway_diff(struct unpack_trees_options *o,
 429                            const struct cache_entry *idx,
 430                            const struct cache_entry *tree)
 431 {
 432         struct rev_info *revs = o->unpack_data;
 433         int match_missing, cached;
 434
 435         /*
 436          * i-t-a entries do not actually exist in the index (if we're
 437          * looking at its content)
 438          */
 439         if (o->index_only &&
 440             revs->diffopt.ita_invisible_in_index &&
 441             idx && ce_intent_to_add(idx)) {
 442                 idx = NULL;
 443                 if (!tree)
 444                         return; /* nothing to diff.. */
 445         }
 446
 447         /* if the entry is not checked out, don't examine work tree */
 448         cached = o->index_only ||
 449                 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
 450
 451         match_missing = revs->match_missing;
 452
 453         if (cached && idx && ce_stage(idx)) {
 454                 struct diff_filepair *pair;
 455                 pair = diff_unmerge(&revs->diffopt, idx->name);
 456                 if (tree)
 457                         fill_filespec(pair->one, &tree->oid, 1,
 458                                       tree->ce_mode);
 459                 return;
 460         }
 461
 462         /*
 463          * Something added to the tree?
 464          */
 465         if (!tree) {
 466                 show_new_file(revs, idx, cached, match_missing);
 467                 return;
 468         }
 469
 470         /*
 471          * Something removed from the tree?
 472          */
 473         if (!idx) {
 474                 if (S_ISSPARSEDIR(tree->ce_mode)) {
 475                         diff_tree_oid(&tree->oid, NULL, tree->name, &revs->diffopt);
 476                         return;
 477                 }
 478
 479                 diff_index_show_file(revs, "-", tree, &tree->oid, 1,
 480                                      tree->ce_mode, 0);
 481                 return;
 482         }
 483
 484         /* Show difference between old and new */
 485         show_modified(revs, tree, idx, 1, cached, match_missing);
 486 }
 487
 488 /*
 489  * The unpack_trees() interface is designed for merging, so
 490  * the different source entries are designed primarily for
 491  * the source trees, with the old index being really mainly
 492  * used for being replaced by the result.
 493  *
 494  * For diffing, the index is more important, and we only have a
 495  * single tree.
 496  *
 497  * We're supposed to advance o->pos to skip what we have already processed.
 498  *
 499  * This wrapper makes it all more readable, and takes care of all
 500  * the fairly complex unpack_trees() semantic requirements, including
 501  * the skipping, the path matching, the type conflict cases etc.
 502  */
 503 static int oneway_diff(const struct cache_entry * const *src,
 504                        struct unpack_trees_options *o)
 505 {
 506         const struct cache_entry *idx = src[0];
 507         const struct cache_entry *tree = src[1];
 508         struct rev_info *revs = o->unpack_data;
 509
 510         /*
 511          * Unpack-trees generates a DF/conflict entry if
 512          * there was a directory in the index and a tree
 513          * in the tree. From a diff standpoint, that's a
 514          * delete of the tree and a create of the file.
 515          */
 516         if (tree == o->df_conflict_entry)
 517                 tree = NULL;
 518
 519         if (ce_path_match(revs->diffopt.repo->index,
 520                           idx ? idx : tree,
 521                           &revs->prune_data, NULL)) {
 522                 do_oneway_diff(o, idx, tree);
 523                 if (diff_can_quit_early(&revs->diffopt)) {
 524                         o->exiting_early = 1;
 525                         return -1;
 526                 }
 527         }
 528
 529         return 0;
 530 }
 531
 532 static int diff_cache(struct rev_info *revs,
 533                       const struct object_id *tree_oid,
 534                       const char *tree_name,
 535                       int cached)
 536 {
 537         struct tree *tree;
 538         struct tree_desc t;
 539         struct unpack_trees_options opts;
 540
 541         tree = parse_tree_indirect(tree_oid);
 542         if (!tree)
 543                 return error("bad tree object %s",
 544                              tree_name ? tree_name : oid_to_hex(tree_oid));
 545         memset(&opts, 0, sizeof(opts));
 546         opts.head_idx = 1;
 547         opts.index_only = cached;
 548         opts.diff_index_cached = (cached &&
 549                                   !revs->diffopt.flags.find_copies_harder);
 550         opts.merge = 1;
 551         opts.fn = oneway_diff;
 552         opts.unpack_data = revs;
 553         opts.src_index = revs->diffopt.repo->index;
 554         opts.dst_index = NULL;
 555         opts.pathspec = &revs->diffopt.pathspec;
 556         opts.pathspec->recursive = 1;
 557
 558         init_tree_desc(&t, tree->buffer, tree->size);
 559         return unpack_trees(1, &t, &opts);
 560 }
 561
 562 void diff_get_merge_base(const struct rev_info *revs, struct object_id *mb)
 563 {
 564         int i;
 565         struct commit *mb_child[2] = {0};
 566         struct commit_list *merge_bases;
 567
 568         for (i = 0; i < revs->pending.nr; i++) {
 569                 struct object *obj = revs->pending.objects[i].item;
 570                 if (obj->flags)
 571                         die(_("--merge-base does not work with ranges"));
 572                 if (obj->type != OBJ_COMMIT)
 573                         die(_("--merge-base only works with commits"));
 574         }
 575
 576         /*
 577          * This check must go after the for loop above because A...B
 578          * ranges produce three pending commits, resulting in a
 579          * misleading error message.
 580          */
 581         if (revs->pending.nr < 1 || revs->pending.nr > 2)
 582                 BUG("unexpected revs->pending.nr: %d", revs->pending.nr);
 583
 584         for (i = 0; i < revs->pending.nr; i++)
 585                 mb_child[i] = lookup_commit_reference(the_repository, &revs->pending.objects[i].item->oid);
 586         if (revs->pending.nr == 1) {
 587                 struct object_id oid;
 588
 589                 if (repo_get_oid(the_repository, "HEAD", &oid))
 590                         die(_("unable to get HEAD"));
 591
 592                 mb_child[1] = lookup_commit_reference(the_repository, &oid);
 593         }
 594
 595         merge_bases = repo_get_merge_bases(the_repository, mb_child[0], mb_child[1]);
 596         if (!merge_bases)
 597                 die(_("no merge base found"));
 598         if (merge_bases->next)
 599                 die(_("multiple merge bases found"));
 600
 601         oidcpy(mb, &merge_bases->item->object.oid);
 602
 603         free_commit_list(merge_bases);
 604 }
 605
 606 int run_diff_index(struct rev_info *revs, unsigned int option)
 607 {
 608         struct object_array_entry *ent;
 609         int cached = !!(option & DIFF_INDEX_CACHED);
 610         int merge_base = !!(option & DIFF_INDEX_MERGE_BASE);
 611         struct object_id oid;
 612         const char *name;
 613         char merge_base_hex[GIT_MAX_HEXSZ + 1];
 614         struct index_state *istate = revs->diffopt.repo->index;
 615
 616         if (revs->pending.nr != 1)
 617                 BUG("run_diff_index must be passed exactly one tree");
 618
 619         trace_performance_enter();
 620         ent = revs->pending.objects;
 621
 622         refresh_fsmonitor(istate);
 623
 624         if (merge_base) {
 625                 diff_get_merge_base(revs, &oid);
 626                 name = oid_to_hex_r(merge_base_hex, &oid);
 627         } else {
 628                 oidcpy(&oid, &ent->item->oid);
 629                 name = ent->name;
 630         }
 631
 632         if (diff_cache(revs, &oid, name, cached))
 633                 exit(128);
 634
 635         diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
 636         diffcore_fix_diff_index();
 637         diffcore_std(&revs->diffopt);
 638         diff_flush(&revs->diffopt);
 639         trace_performance_leave("diff-index");
 640         return 0;
 641 }
 642
 643 int do_diff_cache(const struct object_id *tree_oid, struct diff_options *opt)
 644 {
 645         struct rev_info revs;
 646
 647         repo_init_revisions(opt->repo, &revs, NULL);
 648         copy_pathspec(&revs.prune_data, &opt->pathspec);
 649         diff_setup_done(&revs.diffopt);
 650         revs.diffopt = *opt;
 651
 652         if (diff_cache(&revs, tree_oid, NULL, 1))
 653                 exit(128);
 654         release_revisions(&revs);
 655         return 0;
 656 }
 657
 658 int index_differs_from(struct repository *r,
 659                        const char *def, const struct diff_flags *flags,
 660                        int ita_invisible_in_index)
 661 {
 662         struct rev_info rev;
 663         struct setup_revision_opt opt;
 664         unsigned has_changes;
 665
 666         repo_init_revisions(r, &rev, NULL);
 667         memset(&opt, 0, sizeof(opt));
 668         opt.def = def;
 669         setup_revisions(0, NULL, &rev, &opt);
 670         rev.diffopt.flags.quick = 1;
 671         rev.diffopt.flags.exit_with_status = 1;
 672         if (flags)
 673                 diff_flags_or(&rev.diffopt.flags, flags);
 674         rev.diffopt.ita_invisible_in_index = ita_invisible_in_index;
 675         run_diff_index(&rev, 1);
 676         has_changes = rev.diffopt.flags.has_changes;
 677         release_revisions(&rev);
 678         return (has_changes != 0);
 679 }
 680
 681 static struct strbuf *idiff_prefix_cb(struct diff_options *opt UNUSED, void *data)
 682 {
 683         return data;
 684 }
 685
 686 void show_interdiff(const struct object_id *oid1, const struct object_id *oid2,
 687                     int indent, struct diff_options *diffopt)
 688 {
 689         struct diff_options opts;
 690         struct strbuf prefix = STRBUF_INIT;
 691
 692         memcpy(&opts, diffopt, sizeof(opts));
 693         opts.output_format = DIFF_FORMAT_PATCH;
 694         opts.output_prefix = idiff_prefix_cb;
 695         strbuf_addchars(&prefix, ' ', indent);
 696         opts.output_prefix_data = &prefix;
 697         diff_setup_done(&opts);
 698
 699         diff_tree_oid(oid1, oid2, "", &opts);
 700         diffcore_std(&opts);
 701         diff_flush(&opts);
 702
 703         strbuf_release(&prefix);
 704 }