diff-lib.c

   1 /*
   2  * Copyright (C) 2005 Junio C Hamano
   3  */
   4 #include "git-compat-util.h"
   5 #include "commit.h"
   6 #include "diff.h"
   7 #include "diffcore.h"
   8 #include "gettext.h"
   9 #include "hash.h"
  10 #include "hex.h"
  11 #include "object-name.h"
  12 #include "read-cache.h"
  13 #include "revision.h"
  14 #include "cache-tree.h"
  15 #include "unpack-trees.h"
  16 #include "refs.h"
  17 #include "repository.h"
  18 #include "submodule.h"
  19 #include "symlinks.h"
  20 #include "trace.h"
  21 #include "dir.h"
  22 #include "fsmonitor.h"
  23 #include "commit-reach.h"
  24
  25 /*
  26  * diff-files
  27  */
  28
  29 /*
  30  * Has the work tree entity been removed?
  31  *
  32  * Return 1 if it was removed from the work tree, 0 if an entity to be
  33  * compared with the cache entry ce still exists (the latter includes
  34  * the case where a directory that is not a submodule repository
  35  * exists for ce that is a submodule -- it is a submodule that is not
  36  * checked out).  Return negative for an error.
  37  */
  38 static int check_removed(const struct cache_entry *ce, struct stat *st)
  39 {
  40         int stat_err;
  41
  42         if (!(ce->ce_flags & CE_FSMONITOR_VALID))
  43                 stat_err = lstat(ce->name, st);
  44         else
  45                 stat_err = fake_lstat(ce, st);
  46         if (stat_err < 0) {
  47                 if (!is_missing_file_error(errno))
  48                         return -1;
  49                 return 1;
  50         }
  51
  52         if (has_symlink_leading_path(ce->name, ce_namelen(ce)))
  53                 return 1;
  54         if (S_ISDIR(st->st_mode)) {
  55                 struct object_id sub;
  56
  57                 /*
  58                  * If ce is already a gitlink, we can have a plain
  59                  * directory (i.e. the submodule is not checked out),
  60                  * or a checked out submodule.  Either case this is not
  61                  * a case where something was removed from the work tree,
  62                  * so we will return 0.
  63                  *
  64                  * Otherwise, if the directory is not a submodule
  65                  * repository, that means ce which was a blob turned into
  66                  * a directory --- the blob was removed!
  67                  */
  68                 if (!S_ISGITLINK(ce->ce_mode) &&
  69                     resolve_gitlink_ref(ce->name, "HEAD", &sub))
  70                         return 1;
  71         }
  72         return 0;
  73 }
  74
  75 /*
  76  * Has a file changed or has a submodule new commits or a dirty work tree?
  77  *
  78  * Return 1 when changes are detected, 0 otherwise. If the DIRTY_SUBMODULES
  79  * option is set, the caller does not only want to know if a submodule is
  80  * modified at all but wants to know all the conditions that are met (new
  81  * commits, untracked content and/or modified content).
  82  */
  83 static int match_stat_with_submodule(struct diff_options *diffopt,
  84                                      const struct cache_entry *ce,
  85                                      struct stat *st, unsigned ce_option,
  86                                      unsigned *dirty_submodule)
  87 {
  88         int changed = ie_match_stat(diffopt->repo->index, ce, st, ce_option);
  89         if (S_ISGITLINK(ce->ce_mode)) {
  90                 struct diff_flags orig_flags = diffopt->flags;
  91                 if (!diffopt->flags.override_submodule_config)
  92                         set_diffopt_flags_from_submodule_config(diffopt, ce->name);
  93                 if (diffopt->flags.ignore_submodules)
  94                         changed = 0;
  95                 else if (!diffopt->flags.ignore_dirty_submodules &&
  96                          (!changed || diffopt->flags.dirty_submodules))
  97                         *dirty_submodule = is_submodule_modified(ce->name,
  98                                                                  diffopt->flags.ignore_untracked_in_submodules);
  99                 diffopt->flags = orig_flags;
 100         }
 101         return changed;
 102 }
 103
 104 void run_diff_files(struct rev_info *revs, unsigned int option)
 105 {
 106         int entries, i;
 107         int diff_unmerged_stage = revs->max_count;
 108         unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
 109                               ? CE_MATCH_RACY_IS_DIRTY : 0);
 110         uint64_t start = getnanotime();
 111         struct index_state *istate = revs->diffopt.repo->index;
 112
 113         diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
 114
 115         refresh_fsmonitor(istate);
 116
 117         if (diff_unmerged_stage < 0)
 118                 diff_unmerged_stage = 2;
 119         entries = istate->cache_nr;
 120         for (i = 0; i < entries; i++) {
 121                 unsigned int oldmode, newmode;
 122                 struct cache_entry *ce = istate->cache[i];
 123                 int changed;
 124                 unsigned dirty_submodule = 0;
 125                 const struct object_id *old_oid, *new_oid;
 126
 127                 if (diff_can_quit_early(&revs->diffopt))
 128                         break;
 129
 130                 /*
 131                  * NEEDSWORK:
 132                  * Here we filter with pathspec but the result is further
 133                  * filtered out when --relative is in effect.  To end-users,
 134                  * a pathspec element that matched only to paths outside the
 135                  * current directory is like not matching anything at all;
 136                  * the handling of ps_matched[] here may become problematic
 137                  * if/when we add the "--error-unmatch" option to "git diff".
 138                  */
 139                 if (!ce_path_match(istate, ce, &revs->prune_data, revs->ps_matched))
 140                         continue;
 141
 142                 if (revs->diffopt.prefix &&
 143                     strncmp(ce->name, revs->diffopt.prefix, revs->diffopt.prefix_length))
 144                         continue;
 145
 146                 if (ce_stage(ce)) {
 147                         struct combine_diff_path *dpath;
 148                         struct diff_filepair *pair;
 149                         unsigned int wt_mode = 0;
 150                         int num_compare_stages = 0;
 151                         size_t path_len;
 152                         struct stat st;
 153
 154                         path_len = ce_namelen(ce);
 155
 156                         dpath = xmalloc(combine_diff_path_size(5, path_len));
 157                         dpath->path = (char *) &(dpath->parent[5]);
 158
 159                         dpath->next = NULL;
 160                         memcpy(dpath->path, ce->name, path_len);
 161                         dpath->path[path_len] = '\0';
 162                         oidclr(&dpath->oid);
 163                         memset(&(dpath->parent[0]), 0,
 164                                sizeof(struct combine_diff_parent)*5);
 165
 166                         changed = check_removed(ce, &st);
 167                         if (!changed)
 168                                 wt_mode = ce_mode_from_stat(ce, st.st_mode);
 169                         else {
 170                                 if (changed < 0) {
 171                                         perror(ce->name);
 172                                         continue;
 173                                 }
 174                                 wt_mode = 0;
 175                         }
 176                         dpath->mode = wt_mode;
 177
 178                         while (i < entries) {
 179                                 struct cache_entry *nce = istate->cache[i];
 180                                 int stage;
 181
 182                                 if (strcmp(ce->name, nce->name))
 183                                         break;
 184
 185                                 /* Stage #2 (ours) is the first parent,
 186                                  * stage #3 (theirs) is the second.
 187                                  */
 188                                 stage = ce_stage(nce);
 189                                 if (2 <= stage) {
 190                                         int mode = nce->ce_mode;
 191                                         num_compare_stages++;
 192                                         oidcpy(&dpath->parent[stage - 2].oid,
 193                                                &nce->oid);
 194                                         dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
 195                                         dpath->parent[stage-2].status =
 196                                                 DIFF_STATUS_MODIFIED;
 197                                 }
 198
 199                                 /* diff against the proper unmerged stage */
 200                                 if (stage == diff_unmerged_stage)
 201                                         ce = nce;
 202                                 i++;
 203                         }
 204                         /*
 205                          * Compensate for loop update
 206                          */
 207                         i--;
 208
 209                         if (revs->combine_merges && num_compare_stages == 2) {
 210                                 show_combined_diff(dpath, 2, revs);
 211                                 free(dpath);
 212                                 continue;
 213                         }
 214                         FREE_AND_NULL(dpath);
 215
 216                         /*
 217                          * Show the diff for the 'ce' if we found the one
 218                          * from the desired stage.
 219                          */
 220                         pair = diff_unmerge(&revs->diffopt, ce->name);
 221                         if (wt_mode)
 222                                 pair->two->mode = wt_mode;
 223                         if (ce_stage(ce) != diff_unmerged_stage)
 224                                 continue;
 225                 }
 226
 227                 if (ce_uptodate(ce) || ce_skip_worktree(ce))
 228                         continue;
 229
 230                 /*
 231                  * When CE_VALID is set (via "update-index --assume-unchanged"
 232                  * or via adding paths while core.ignorestat is set to true),
 233                  * the user has promised that the working tree file for that
 234                  * path will not be modified.  When CE_FSMONITOR_VALID is true,
 235                  * the fsmonitor knows that the path hasn't been modified since
 236                  * we refreshed the cached stat information.  In either case,
 237                  * we do not have to stat to see if the path has been removed
 238                  * or modified.
 239                  */
 240                 if (ce->ce_flags & (CE_VALID | CE_FSMONITOR_VALID)) {
 241                         changed = 0;
 242                         newmode = ce->ce_mode;
 243                 } else {
 244                         struct stat st;
 245
 246                         changed = check_removed(ce, &st);
 247                         if (changed) {
 248                                 if (changed < 0) {
 249                                         perror(ce->name);
 250                                         continue;
 251                                 }
 252                                 diff_addremove(&revs->diffopt, '-', ce->ce_mode,
 253                                                &ce->oid,
 254                                                !is_null_oid(&ce->oid),
 255                                                ce->name, 0);
 256                                 continue;
 257                         } else if (revs->diffopt.ita_invisible_in_index &&
 258                                    ce_intent_to_add(ce)) {
 259                                 newmode = ce_mode_from_stat(ce, st.st_mode);
 260                                 diff_addremove(&revs->diffopt, '+', newmode,
 261                                                null_oid(), 0, ce->name, 0);
 262                                 continue;
 263                         }
 264
 265                         changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
 266                                                             ce_option, &dirty_submodule);
 267                         newmode = ce_mode_from_stat(ce, st.st_mode);
 268                 }
 269
 270                 if (!changed && !dirty_submodule) {
 271                         ce_mark_uptodate(ce);
 272                         mark_fsmonitor_valid(istate, ce);
 273                         if (!revs->diffopt.flags.find_copies_harder)
 274                                 continue;
 275                 }
 276                 oldmode = ce->ce_mode;
 277                 old_oid = &ce->oid;
 278                 new_oid = changed ? null_oid() : &ce->oid;
 279                 diff_change(&revs->diffopt, oldmode, newmode,
 280                             old_oid, new_oid,
 281                             !is_null_oid(old_oid),
 282                             !is_null_oid(new_oid),
 283                             ce->name, 0, dirty_submodule);
 284
 285         }
 286         diffcore_std(&revs->diffopt);
 287         diff_flush(&revs->diffopt);
 288         trace_performance_since(start, "diff-files");
 289 }
 290
 291 /*
 292  * diff-index
 293  */
 294
 295 /* A file entry went away or appeared */
 296 static void diff_index_show_file(struct rev_info *revs,
 297                                  const char *prefix,
 298                                  const struct cache_entry *ce,
 299                                  const struct object_id *oid, int oid_valid,
 300                                  unsigned int mode,
 301                                  unsigned dirty_submodule)
 302 {
 303         diff_addremove(&revs->diffopt, prefix[0], mode,
 304                        oid, oid_valid, ce->name, dirty_submodule);
 305 }
 306
 307 static int get_stat_data(const struct index_state *istate,
 308                          const struct cache_entry *ce,
 309                          const struct object_id **oidp,
 310                          unsigned int *modep,
 311                          int cached, int match_missing,
 312                          unsigned *dirty_submodule, struct diff_options *diffopt)
 313 {
 314         const struct object_id *oid = &ce->oid;
 315         unsigned int mode = ce->ce_mode;
 316
 317         if (!cached && !ce_uptodate(ce)) {
 318                 int changed;
 319                 struct stat st;
 320                 changed = check_removed(ce, &st);
 321                 if (changed < 0)
 322                         return -1;
 323                 else if (changed) {
 324                         if (match_missing) {
 325                                 *oidp = oid;
 326                                 *modep = mode;
 327                                 return 0;
 328                         }
 329                         return -1;
 330                 }
 331                 changed = match_stat_with_submodule(diffopt, ce, &st,
 332                                                     0, dirty_submodule);
 333                 if (changed) {
 334                         mode = ce_mode_from_stat(ce, st.st_mode);
 335                         oid = null_oid();
 336                 }
 337         }
 338
 339         *oidp = oid;
 340         *modep = mode;
 341         return 0;
 342 }
 343
 344 static void show_new_file(struct rev_info *revs,
 345                           const struct cache_entry *new_file,
 346                           int cached, int match_missing)
 347 {
 348         const struct object_id *oid;
 349         unsigned int mode;
 350         unsigned dirty_submodule = 0;
 351         struct index_state *istate = revs->diffopt.repo->index;
 352
 353         if (new_file && S_ISSPARSEDIR(new_file->ce_mode)) {
 354                 diff_tree_oid(NULL, &new_file->oid, new_file->name, &revs->diffopt);
 355                 return;
 356         }
 357
 358         /*
 359          * New file in the index: it might actually be different in
 360          * the working tree.
 361          */
 362         if (get_stat_data(istate, new_file, &oid, &mode, cached, match_missing,
 363             &dirty_submodule, &revs->diffopt) < 0)
 364                 return;
 365
 366         diff_index_show_file(revs, "+", new_file, oid, !is_null_oid(oid), mode, dirty_submodule);
 367 }
 368
 369 static int show_modified(struct rev_info *revs,
 370                          const struct cache_entry *old_entry,
 371                          const struct cache_entry *new_entry,
 372                          int report_missing,
 373                          int cached, int match_missing)
 374 {
 375         unsigned int mode, oldmode;
 376         const struct object_id *oid;
 377         unsigned dirty_submodule = 0;
 378         struct index_state *istate = revs->diffopt.repo->index;
 379
 380         assert(S_ISSPARSEDIR(old_entry->ce_mode) ==
 381                S_ISSPARSEDIR(new_entry->ce_mode));
 382
 383         /*
 384          * If both are sparse directory entries, then expand the
 385          * modifications to the file level. If only one was a sparse
 386          * directory, then they appear as an add and delete instead of
 387          * a modification.
 388          */
 389         if (S_ISSPARSEDIR(new_entry->ce_mode)) {
 390                 diff_tree_oid(&old_entry->oid, &new_entry->oid, new_entry->name, &revs->diffopt);
 391                 return 0;
 392         }
 393
 394         if (get_stat_data(istate, new_entry, &oid, &mode, cached, match_missing,
 395                           &dirty_submodule, &revs->diffopt) < 0) {
 396                 if (report_missing)
 397                         diff_index_show_file(revs, "-", old_entry,
 398                                              &old_entry->oid, 1, old_entry->ce_mode,
 399                                              0);
 400                 return -1;
 401         }
 402
 403         if (revs->combine_merges && !cached &&
 404             (!oideq(oid, &old_entry->oid) || !oideq(&old_entry->oid, &new_entry->oid))) {
 405                 struct combine_diff_path *p;
 406                 int pathlen = ce_namelen(new_entry);
 407
 408                 p = xmalloc(combine_diff_path_size(2, pathlen));
 409                 p->path = (char *) &p->parent[2];
 410                 p->next = NULL;
 411                 memcpy(p->path, new_entry->name, pathlen);
 412                 p->path[pathlen] = 0;
 413                 p->mode = mode;
 414                 oidclr(&p->oid);
 415                 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
 416                 p->parent[0].status = DIFF_STATUS_MODIFIED;
 417                 p->parent[0].mode = new_entry->ce_mode;
 418                 oidcpy(&p->parent[0].oid, &new_entry->oid);
 419                 p->parent[1].status = DIFF_STATUS_MODIFIED;
 420                 p->parent[1].mode = old_entry->ce_mode;
 421                 oidcpy(&p->parent[1].oid, &old_entry->oid);
 422                 show_combined_diff(p, 2, revs);
 423                 free(p);
 424                 return 0;
 425         }
 426
 427         oldmode = old_entry->ce_mode;
 428         if (mode == oldmode && oideq(oid, &old_entry->oid) && !dirty_submodule &&
 429             !revs->diffopt.flags.find_copies_harder)
 430                 return 0;
 431
 432         diff_change(&revs->diffopt, oldmode, mode,
 433                     &old_entry->oid, oid, 1, !is_null_oid(oid),
 434                     old_entry->name, 0, dirty_submodule);
 435         return 0;
 436 }
 437
 438 /*
 439  * This gets a mix of an existing index and a tree, one pathname entry
 440  * at a time. The index entry may be a single stage-0 one, but it could
 441  * also be multiple unmerged entries (in which case idx_pos/idx_nr will
 442  * give you the position and number of entries in the index).
 443  */
 444 static void do_oneway_diff(struct unpack_trees_options *o,
 445                            const struct cache_entry *idx,
 446                            const struct cache_entry *tree)
 447 {
 448         struct rev_info *revs = o->unpack_data;
 449         int match_missing, cached;
 450
 451         /*
 452          * i-t-a entries do not actually exist in the index (if we're
 453          * looking at its content)
 454          */
 455         if (o->index_only &&
 456             revs->diffopt.ita_invisible_in_index &&
 457             idx && ce_intent_to_add(idx)) {
 458                 idx = NULL;
 459                 if (!tree)
 460                         return; /* nothing to diff.. */
 461         }
 462
 463         /* if the entry is not checked out, don't examine work tree */
 464         cached = o->index_only ||
 465                 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
 466
 467         match_missing = revs->match_missing;
 468
 469         if (cached && idx && ce_stage(idx)) {
 470                 struct diff_filepair *pair;
 471                 pair = diff_unmerge(&revs->diffopt, idx->name);
 472                 if (tree)
 473                         fill_filespec(pair->one, &tree->oid, 1,
 474                                       tree->ce_mode);
 475                 return;
 476         }
 477
 478         /*
 479          * Something added to the tree?
 480          */
 481         if (!tree) {
 482                 show_new_file(revs, idx, cached, match_missing);
 483                 return;
 484         }
 485
 486         /*
 487          * Something removed from the tree?
 488          */
 489         if (!idx) {
 490                 if (S_ISSPARSEDIR(tree->ce_mode)) {
 491                         diff_tree_oid(&tree->oid, NULL, tree->name, &revs->diffopt);
 492                         return;
 493                 }
 494
 495                 diff_index_show_file(revs, "-", tree, &tree->oid, 1,
 496                                      tree->ce_mode, 0);
 497                 return;
 498         }
 499
 500         /* Show difference between old and new */
 501         show_modified(revs, tree, idx, 1, cached, match_missing);
 502 }
 503
 504 /*
 505  * The unpack_trees() interface is designed for merging, so
 506  * the different source entries are designed primarily for
 507  * the source trees, with the old index being really mainly
 508  * used for being replaced by the result.
 509  *
 510  * For diffing, the index is more important, and we only have a
 511  * single tree.
 512  *
 513  * We're supposed to advance o->pos to skip what we have already processed.
 514  *
 515  * This wrapper makes it all more readable, and takes care of all
 516  * the fairly complex unpack_trees() semantic requirements, including
 517  * the skipping, the path matching, the type conflict cases etc.
 518  */
 519 static int oneway_diff(const struct cache_entry * const *src,
 520                        struct unpack_trees_options *o)
 521 {
 522         const struct cache_entry *idx = src[0];
 523         const struct cache_entry *tree = src[1];
 524         struct rev_info *revs = o->unpack_data;
 525
 526         /*
 527          * Unpack-trees generates a DF/conflict entry if
 528          * there was a directory in the index and a tree
 529          * in the tree. From a diff standpoint, that's a
 530          * delete of the tree and a create of the file.
 531          */
 532         if (tree == o->df_conflict_entry)
 533                 tree = NULL;
 534
 535         if (ce_path_match(revs->diffopt.repo->index,
 536                           idx ? idx : tree,
 537                           &revs->prune_data, NULL)) {
 538                 do_oneway_diff(o, idx, tree);
 539                 if (diff_can_quit_early(&revs->diffopt)) {
 540                         o->exiting_early = 1;
 541                         return -1;
 542                 }
 543         }
 544
 545         return 0;
 546 }
 547
 548 static int diff_cache(struct rev_info *revs,
 549                       const struct object_id *tree_oid,
 550                       const char *tree_name,
 551                       int cached)
 552 {
 553         struct tree *tree;
 554         struct tree_desc t;
 555         struct unpack_trees_options opts;
 556
 557         tree = parse_tree_indirect(tree_oid);
 558         if (!tree)
 559                 return error("bad tree object %s",
 560                              tree_name ? tree_name : oid_to_hex(tree_oid));
 561         memset(&opts, 0, sizeof(opts));
 562         opts.head_idx = 1;
 563         opts.index_only = cached;
 564         opts.diff_index_cached = (cached &&
 565                                   !revs->diffopt.flags.find_copies_harder);
 566         opts.merge = 1;
 567         opts.fn = oneway_diff;
 568         opts.unpack_data = revs;
 569         opts.src_index = revs->diffopt.repo->index;
 570         opts.dst_index = NULL;
 571         opts.pathspec = &revs->diffopt.pathspec;
 572         opts.pathspec->recursive = 1;
 573
 574         init_tree_desc(&t, &tree->object.oid, tree->buffer, tree->size);
 575         return unpack_trees(1, &t, &opts);
 576 }
 577
 578 void diff_get_merge_base(const struct rev_info *revs, struct object_id *mb)
 579 {
 580         int i;
 581         struct commit *mb_child[2] = {0};
 582         struct commit_list *merge_bases = NULL;
 583
 584         for (i = 0; i < revs->pending.nr; i++) {
 585                 struct object *obj = revs->pending.objects[i].item;
 586                 if (obj->flags)
 587                         die(_("--merge-base does not work with ranges"));
 588         }
 589
 590         /*
 591          * This check must go after the for loop above because A...B
 592          * ranges produce three pending commits, resulting in a
 593          * misleading error message.
 594          */
 595         if (revs->pending.nr < 1 || revs->pending.nr > 2)
 596                 BUG("unexpected revs->pending.nr: %d", revs->pending.nr);
 597
 598         for (i = 0; i < revs->pending.nr; i++)
 599                 mb_child[i] = lookup_commit_reference(the_repository, &revs->pending.objects[i].item->oid);
 600         if (revs->pending.nr == 1) {
 601                 struct object_id oid;
 602
 603                 if (repo_get_oid(the_repository, "HEAD", &oid))
 604                         die(_("unable to get HEAD"));
 605
 606                 mb_child[1] = lookup_commit_reference(the_repository, &oid);
 607         }
 608
 609         if (repo_get_merge_bases(the_repository, mb_child[0], mb_child[1], &merge_bases) < 0)
 610                 exit(128);
 611         if (!merge_bases)
 612                 die(_("no merge base found"));
 613         if (merge_bases->next)
 614                 die(_("multiple merge bases found"));
 615
 616         oidcpy(mb, &merge_bases->item->object.oid);
 617
 618         free_commit_list(merge_bases);
 619 }
 620
 621 void run_diff_index(struct rev_info *revs, unsigned int option)
 622 {
 623         struct object_array_entry *ent;
 624         int cached = !!(option & DIFF_INDEX_CACHED);
 625         int merge_base = !!(option & DIFF_INDEX_MERGE_BASE);
 626         struct object_id oid;
 627         const char *name;
 628         char merge_base_hex[GIT_MAX_HEXSZ + 1];
 629         struct index_state *istate = revs->diffopt.repo->index;
 630
 631         if (revs->pending.nr != 1)
 632                 BUG("run_diff_index must be passed exactly one tree");
 633
 634         trace_performance_enter();
 635         ent = revs->pending.objects;
 636
 637         refresh_fsmonitor(istate);
 638
 639         if (merge_base) {
 640                 diff_get_merge_base(revs, &oid);
 641                 name = oid_to_hex_r(merge_base_hex, &oid);
 642         } else {
 643                 oidcpy(&oid, &ent->item->oid);
 644                 name = ent->name;
 645         }
 646
 647         if (diff_cache(revs, &oid, name, cached))
 648                 exit(128);
 649
 650         diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
 651         diffcore_fix_diff_index();
 652         diffcore_std(&revs->diffopt);
 653         diff_flush(&revs->diffopt);
 654         trace_performance_leave("diff-index");
 655 }
 656
 657 int do_diff_cache(const struct object_id *tree_oid, struct diff_options *opt)
 658 {
 659         struct rev_info revs;
 660
 661         repo_init_revisions(opt->repo, &revs, NULL);
 662         copy_pathspec(&revs.prune_data, &opt->pathspec);
 663         revs.diffopt = *opt;
 664
 665         if (diff_cache(&revs, tree_oid, NULL, 1))
 666                 exit(128);
 667         release_revisions(&revs);
 668         return 0;
 669 }
 670
 671 int index_differs_from(struct repository *r,
 672                        const char *def, const struct diff_flags *flags,
 673                        int ita_invisible_in_index)
 674 {
 675         struct rev_info rev;
 676         struct setup_revision_opt opt;
 677         unsigned has_changes;
 678
 679         repo_init_revisions(r, &rev, NULL);
 680         memset(&opt, 0, sizeof(opt));
 681         opt.def = def;
 682         setup_revisions(0, NULL, &rev, &opt);
 683         rev.diffopt.flags.quick = 1;
 684         rev.diffopt.flags.exit_with_status = 1;
 685         if (flags) {
 686                 diff_flags_or(&rev.diffopt.flags, flags);
 687                 /*
 688                  * Now that flags are merged, honor override_submodule_config
 689                  * and ignore_submodules from passed flags.
 690                  */
 691                 if (flags->override_submodule_config)
 692                         rev.diffopt.flags.ignore_submodules = flags->ignore_submodules;
 693         }
 694         rev.diffopt.ita_invisible_in_index = ita_invisible_in_index;
 695         run_diff_index(&rev, DIFF_INDEX_CACHED);
 696         has_changes = rev.diffopt.flags.has_changes;
 697         release_revisions(&rev);
 698         return (has_changes != 0);
 699 }
 700
 701 static struct strbuf *idiff_prefix_cb(struct diff_options *opt UNUSED, void *data)
 702 {
 703         return data;
 704 }
 705
 706 void show_interdiff(const struct object_id *oid1, const struct object_id *oid2,
 707                     int indent, struct diff_options *diffopt)
 708 {
 709         struct diff_options opts;
 710         struct strbuf prefix = STRBUF_INIT;
 711
 712         memcpy(&opts, diffopt, sizeof(opts));
 713         opts.output_format = DIFF_FORMAT_PATCH;
 714         opts.output_prefix = idiff_prefix_cb;
 715         strbuf_addchars(&prefix, ' ', indent);
 716         opts.output_prefix_data = &prefix;
 717         diff_setup_done(&opts);
 718
 719         diff_tree_oid(oid1, oid2, "", &opts);
 720         diffcore_std(&opts);
 721         diff_flush(&opts);
 722
 723         strbuf_release(&prefix);
 724 }