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                     repo_resolve_gitlink_ref(the_repository, ce->name,
  70                                              "HEAD", &sub))
  71                         return 1;
  72         }
  73         return 0;
  74 }
  75
  76 /*
  77  * Has a file changed or has a submodule new commits or a dirty work tree?
  78  *
  79  * Return 1 when changes are detected, 0 otherwise. If the DIRTY_SUBMODULES
  80  * option is set, the caller does not only want to know if a submodule is
  81  * modified at all but wants to know all the conditions that are met (new
  82  * commits, untracked content and/or modified content).
  83  */
  84 static int match_stat_with_submodule(struct diff_options *diffopt,
  85                                      const struct cache_entry *ce,
  86                                      struct stat *st, unsigned ce_option,
  87                                      unsigned *dirty_submodule)
  88 {
  89         int changed = ie_match_stat(diffopt->repo->index, ce, st, ce_option);
  90         if (S_ISGITLINK(ce->ce_mode)) {
  91                 struct diff_flags orig_flags = diffopt->flags;
  92                 if (!diffopt->flags.override_submodule_config)
  93                         set_diffopt_flags_from_submodule_config(diffopt, ce->name);
  94                 if (diffopt->flags.ignore_submodules)
  95                         changed = 0;
  96                 else if (!diffopt->flags.ignore_dirty_submodules &&
  97                          (!changed || diffopt->flags.dirty_submodules))
  98                         *dirty_submodule = is_submodule_modified(ce->name,
  99                                                                  diffopt->flags.ignore_untracked_in_submodules);
 100                 diffopt->flags = orig_flags;
 101         }
 102         return changed;
 103 }
 104
 105 void run_diff_files(struct rev_info *revs, unsigned int option)
 106 {
 107         int entries, i;
 108         int diff_unmerged_stage = revs->max_count;
 109         unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
 110                               ? CE_MATCH_RACY_IS_DIRTY : 0);
 111         uint64_t start = getnanotime();
 112         struct index_state *istate = revs->diffopt.repo->index;
 113
 114         diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
 115
 116         refresh_fsmonitor(istate);
 117
 118         if (diff_unmerged_stage < 0)
 119                 diff_unmerged_stage = 2;
 120         entries = istate->cache_nr;
 121         for (i = 0; i < entries; i++) {
 122                 unsigned int oldmode, newmode;
 123                 struct cache_entry *ce = istate->cache[i];
 124                 int changed;
 125                 unsigned dirty_submodule = 0;
 126                 const struct object_id *old_oid, *new_oid;
 127
 128                 if (diff_can_quit_early(&revs->diffopt))
 129                         break;
 130
 131                 /*
 132                  * NEEDSWORK:
 133                  * Here we filter with pathspec but the result is further
 134                  * filtered out when --relative is in effect.  To end-users,
 135                  * a pathspec element that matched only to paths outside the
 136                  * current directory is like not matching anything at all;
 137                  * the handling of ps_matched[] here may become problematic
 138                  * if/when we add the "--error-unmatch" option to "git diff".
 139                  */
 140                 if (!ce_path_match(istate, ce, &revs->prune_data, revs->ps_matched))
 141                         continue;
 142
 143                 if (revs->diffopt.prefix &&
 144                     strncmp(ce->name, revs->diffopt.prefix, revs->diffopt.prefix_length))
 145                         continue;
 146
 147                 if (ce_stage(ce)) {
 148                         struct combine_diff_path *dpath;
 149                         struct diff_filepair *pair;
 150                         unsigned int wt_mode = 0;
 151                         int num_compare_stages = 0;
 152                         size_t path_len;
 153                         struct stat st;
 154
 155                         path_len = ce_namelen(ce);
 156
 157                         dpath = xmalloc(combine_diff_path_size(5, path_len));
 158                         dpath->path = (char *) &(dpath->parent[5]);
 159
 160                         dpath->next = NULL;
 161                         memcpy(dpath->path, ce->name, path_len);
 162                         dpath->path[path_len] = '\0';
 163                         oidclr(&dpath->oid, the_repository->hash_algo);
 164                         memset(&(dpath->parent[0]), 0,
 165                                sizeof(struct combine_diff_parent)*5);
 166
 167                         changed = check_removed(ce, &st);
 168                         if (!changed)
 169                                 wt_mode = ce_mode_from_stat(ce, st.st_mode);
 170                         else {
 171                                 if (changed < 0) {
 172                                         perror(ce->name);
 173                                         continue;
 174                                 }
 175                                 wt_mode = 0;
 176                         }
 177                         dpath->mode = wt_mode;
 178
 179                         while (i < entries) {
 180                                 struct cache_entry *nce = istate->cache[i];
 181                                 int stage;
 182
 183                                 if (strcmp(ce->name, nce->name))
 184                                         break;
 185
 186                                 /* Stage #2 (ours) is the first parent,
 187                                  * stage #3 (theirs) is the second.
 188                                  */
 189                                 stage = ce_stage(nce);
 190                                 if (2 <= stage) {
 191                                         int mode = nce->ce_mode;
 192                                         num_compare_stages++;
 193                                         oidcpy(&dpath->parent[stage - 2].oid,
 194                                                &nce->oid);
 195                                         dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
 196                                         dpath->parent[stage-2].status =
 197                                                 DIFF_STATUS_MODIFIED;
 198                                 }
 199
 200                                 /* diff against the proper unmerged stage */
 201                                 if (stage == diff_unmerged_stage)
 202                                         ce = nce;
 203                                 i++;
 204                         }
 205                         /*
 206                          * Compensate for loop update
 207                          */
 208                         i--;
 209
 210                         if (revs->combine_merges && num_compare_stages == 2) {
 211                                 show_combined_diff(dpath, 2, revs);
 212                                 free(dpath);
 213                                 continue;
 214                         }
 215                         FREE_AND_NULL(dpath);
 216
 217                         /*
 218                          * Show the diff for the 'ce' if we found the one
 219                          * from the desired stage.
 220                          */
 221                         pair = diff_unmerge(&revs->diffopt, ce->name);
 222                         if (wt_mode)
 223                                 pair->two->mode = wt_mode;
 224                         if (ce_stage(ce) != diff_unmerged_stage)
 225                                 continue;
 226                 }
 227
 228                 if (ce_uptodate(ce) || ce_skip_worktree(ce))
 229                         continue;
 230
 231                 /*
 232                  * When CE_VALID is set (via "update-index --assume-unchanged"
 233                  * or via adding paths while core.ignorestat is set to true),
 234                  * the user has promised that the working tree file for that
 235                  * path will not be modified.  When CE_FSMONITOR_VALID is true,
 236                  * the fsmonitor knows that the path hasn't been modified since
 237                  * we refreshed the cached stat information.  In either case,
 238                  * we do not have to stat to see if the path has been removed
 239                  * or modified.
 240                  */
 241                 if (ce->ce_flags & (CE_VALID | CE_FSMONITOR_VALID)) {
 242                         changed = 0;
 243                         newmode = ce->ce_mode;
 244                 } else {
 245                         struct stat st;
 246
 247                         changed = check_removed(ce, &st);
 248                         if (changed) {
 249                                 if (changed < 0) {
 250                                         perror(ce->name);
 251                                         continue;
 252                                 }
 253                                 diff_addremove(&revs->diffopt, '-', ce->ce_mode,
 254                                                &ce->oid,
 255                                                !is_null_oid(&ce->oid),
 256                                                ce->name, 0);
 257                                 continue;
 258                         } else if (revs->diffopt.ita_invisible_in_index &&
 259                                    ce_intent_to_add(ce)) {
 260                                 newmode = ce_mode_from_stat(ce, st.st_mode);
 261                                 diff_addremove(&revs->diffopt, '+', newmode,
 262                                                null_oid(), 0, ce->name, 0);
 263                                 continue;
 264                         }
 265
 266                         changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
 267                                                             ce_option, &dirty_submodule);
 268                         newmode = ce_mode_from_stat(ce, st.st_mode);
 269                 }
 270
 271                 if (!changed && !dirty_submodule) {
 272                         ce_mark_uptodate(ce);
 273                         mark_fsmonitor_valid(istate, ce);
 274                         if (!revs->diffopt.flags.find_copies_harder)
 275                                 continue;
 276                 }
 277                 oldmode = ce->ce_mode;
 278                 old_oid = &ce->oid;
 279                 new_oid = changed ? null_oid() : &ce->oid;
 280                 diff_change(&revs->diffopt, oldmode, newmode,
 281                             old_oid, new_oid,
 282                             !is_null_oid(old_oid),
 283                             !is_null_oid(new_oid),
 284                             ce->name, 0, dirty_submodule);
 285
 286         }
 287         diffcore_std(&revs->diffopt);
 288         diff_flush(&revs->diffopt);
 289         trace_performance_since(start, "diff-files");
 290 }
 291
 292 /*
 293  * diff-index
 294  */
 295
 296 /* A file entry went away or appeared */
 297 static void diff_index_show_file(struct rev_info *revs,
 298                                  const char *prefix,
 299                                  const struct cache_entry *ce,
 300                                  const struct object_id *oid, int oid_valid,
 301                                  unsigned int mode,
 302                                  unsigned dirty_submodule)
 303 {
 304         diff_addremove(&revs->diffopt, prefix[0], mode,
 305                        oid, oid_valid, ce->name, dirty_submodule);
 306 }
 307
 308 static int get_stat_data(const struct index_state *istate,
 309                          const struct cache_entry *ce,
 310                          const struct object_id **oidp,
 311                          unsigned int *modep,
 312                          int cached, int match_missing,
 313                          unsigned *dirty_submodule, struct diff_options *diffopt)
 314 {
 315         const struct object_id *oid = &ce->oid;
 316         unsigned int mode = ce->ce_mode;
 317
 318         if (!cached && !ce_uptodate(ce)) {
 319                 int changed;
 320                 struct stat st;
 321                 changed = check_removed(ce, &st);
 322                 if (changed < 0)
 323                         return -1;
 324                 else if (changed) {
 325                         if (match_missing) {
 326                                 *oidp = oid;
 327                                 *modep = mode;
 328                                 return 0;
 329                         }
 330                         return -1;
 331                 }
 332                 changed = match_stat_with_submodule(diffopt, ce, &st,
 333                                                     0, dirty_submodule);
 334                 if (changed) {
 335                         mode = ce_mode_from_stat(ce, st.st_mode);
 336                         oid = null_oid();
 337                 }
 338         }
 339
 340         *oidp = oid;
 341         *modep = mode;
 342         return 0;
 343 }
 344
 345 static void show_new_file(struct rev_info *revs,
 346                           const struct cache_entry *new_file,
 347                           int cached, int match_missing)
 348 {
 349         const struct object_id *oid;
 350         unsigned int mode;
 351         unsigned dirty_submodule = 0;
 352         struct index_state *istate = revs->diffopt.repo->index;
 353
 354         if (new_file && S_ISSPARSEDIR(new_file->ce_mode)) {
 355                 diff_tree_oid(NULL, &new_file->oid, new_file->name, &revs->diffopt);
 356                 return;
 357         }
 358
 359         /*
 360          * New file in the index: it might actually be different in
 361          * the working tree.
 362          */
 363         if (get_stat_data(istate, new_file, &oid, &mode, cached, match_missing,
 364             &dirty_submodule, &revs->diffopt) < 0)
 365                 return;
 366
 367         diff_index_show_file(revs, "+", new_file, oid, !is_null_oid(oid), mode, dirty_submodule);
 368 }
 369
 370 static int show_modified(struct rev_info *revs,
 371                          const struct cache_entry *old_entry,
 372                          const struct cache_entry *new_entry,
 373                          int report_missing,
 374                          int cached, int match_missing)
 375 {
 376         unsigned int mode, oldmode;
 377         const struct object_id *oid;
 378         unsigned dirty_submodule = 0;
 379         struct index_state *istate = revs->diffopt.repo->index;
 380
 381         assert(S_ISSPARSEDIR(old_entry->ce_mode) ==
 382                S_ISSPARSEDIR(new_entry->ce_mode));
 383
 384         /*
 385          * If both are sparse directory entries, then expand the
 386          * modifications to the file level. If only one was a sparse
 387          * directory, then they appear as an add and delete instead of
 388          * a modification.
 389          */
 390         if (S_ISSPARSEDIR(new_entry->ce_mode)) {
 391                 diff_tree_oid(&old_entry->oid, &new_entry->oid, new_entry->name, &revs->diffopt);
 392                 return 0;
 393         }
 394
 395         if (get_stat_data(istate, new_entry, &oid, &mode, cached, match_missing,
 396                           &dirty_submodule, &revs->diffopt) < 0) {
 397                 if (report_missing)
 398                         diff_index_show_file(revs, "-", old_entry,
 399                                              &old_entry->oid, 1, old_entry->ce_mode,
 400                                              0);
 401                 return -1;
 402         }
 403
 404         if (revs->combine_merges && !cached &&
 405             (!oideq(oid, &old_entry->oid) || !oideq(&old_entry->oid, &new_entry->oid))) {
 406                 struct combine_diff_path *p;
 407                 int pathlen = ce_namelen(new_entry);
 408
 409                 p = xmalloc(combine_diff_path_size(2, pathlen));
 410                 p->path = (char *) &p->parent[2];
 411                 p->next = NULL;
 412                 memcpy(p->path, new_entry->name, pathlen);
 413                 p->path[pathlen] = 0;
 414                 p->mode = mode;
 415                 oidclr(&p->oid, the_repository->hash_algo);
 416                 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
 417                 p->parent[0].status = DIFF_STATUS_MODIFIED;
 418                 p->parent[0].mode = new_entry->ce_mode;
 419                 oidcpy(&p->parent[0].oid, &new_entry->oid);
 420                 p->parent[1].status = DIFF_STATUS_MODIFIED;
 421                 p->parent[1].mode = old_entry->ce_mode;
 422                 oidcpy(&p->parent[1].oid, &old_entry->oid);
 423                 show_combined_diff(p, 2, revs);
 424                 free(p);
 425                 return 0;
 426         }
 427
 428         oldmode = old_entry->ce_mode;
 429         if (mode == oldmode && oideq(oid, &old_entry->oid) && !dirty_submodule &&
 430             !revs->diffopt.flags.find_copies_harder)
 431                 return 0;
 432
 433         diff_change(&revs->diffopt, oldmode, mode,
 434                     &old_entry->oid, oid, 1, !is_null_oid(oid),
 435                     old_entry->name, 0, dirty_submodule);
 436         return 0;
 437 }
 438
 439 /*
 440  * This gets a mix of an existing index and a tree, one pathname entry
 441  * at a time. The index entry may be a single stage-0 one, but it could
 442  * also be multiple unmerged entries (in which case idx_pos/idx_nr will
 443  * give you the position and number of entries in the index).
 444  */
 445 static void do_oneway_diff(struct unpack_trees_options *o,
 446                            const struct cache_entry *idx,
 447                            const struct cache_entry *tree)
 448 {
 449         struct rev_info *revs = o->unpack_data;
 450         int match_missing, cached;
 451
 452         /*
 453          * i-t-a entries do not actually exist in the index (if we're
 454          * looking at its content)
 455          */
 456         if (o->index_only &&
 457             revs->diffopt.ita_invisible_in_index &&
 458             idx && ce_intent_to_add(idx)) {
 459                 idx = NULL;
 460                 if (!tree)
 461                         return; /* nothing to diff.. */
 462         }
 463
 464         /* if the entry is not checked out, don't examine work tree */
 465         cached = o->index_only ||
 466                 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
 467
 468         match_missing = revs->match_missing;
 469
 470         if (cached && idx && ce_stage(idx)) {
 471                 struct diff_filepair *pair;
 472                 pair = diff_unmerge(&revs->diffopt, idx->name);
 473                 if (tree)
 474                         fill_filespec(pair->one, &tree->oid, 1,
 475                                       tree->ce_mode);
 476                 return;
 477         }
 478
 479         /*
 480          * Something added to the tree?
 481          */
 482         if (!tree) {
 483                 show_new_file(revs, idx, cached, match_missing);
 484                 return;
 485         }
 486
 487         /*
 488          * Something removed from the tree?
 489          */
 490         if (!idx) {
 491                 if (S_ISSPARSEDIR(tree->ce_mode)) {
 492                         diff_tree_oid(&tree->oid, NULL, tree->name, &revs->diffopt);
 493                         return;
 494                 }
 495
 496                 diff_index_show_file(revs, "-", tree, &tree->oid, 1,
 497                                      tree->ce_mode, 0);
 498                 return;
 499         }
 500
 501         /* Show difference between old and new */
 502         show_modified(revs, tree, idx, 1, cached, match_missing);
 503 }
 504
 505 /*
 506  * The unpack_trees() interface is designed for merging, so
 507  * the different source entries are designed primarily for
 508  * the source trees, with the old index being really mainly
 509  * used for being replaced by the result.
 510  *
 511  * For diffing, the index is more important, and we only have a
 512  * single tree.
 513  *
 514  * We're supposed to advance o->pos to skip what we have already processed.
 515  *
 516  * This wrapper makes it all more readable, and takes care of all
 517  * the fairly complex unpack_trees() semantic requirements, including
 518  * the skipping, the path matching, the type conflict cases etc.
 519  */
 520 static int oneway_diff(const struct cache_entry * const *src,
 521                        struct unpack_trees_options *o)
 522 {
 523         const struct cache_entry *idx = src[0];
 524         const struct cache_entry *tree = src[1];
 525         struct rev_info *revs = o->unpack_data;
 526
 527         /*
 528          * Unpack-trees generates a DF/conflict entry if
 529          * there was a directory in the index and a tree
 530          * in the tree. From a diff standpoint, that's a
 531          * delete of the tree and a create of the file.
 532          */
 533         if (tree == o->df_conflict_entry)
 534                 tree = NULL;
 535
 536         if (ce_path_match(revs->diffopt.repo->index,
 537                           idx ? idx : tree,
 538                           &revs->prune_data, NULL)) {
 539                 do_oneway_diff(o, idx, tree);
 540                 if (diff_can_quit_early(&revs->diffopt)) {
 541                         o->exiting_early = 1;
 542                         return -1;
 543                 }
 544         }
 545
 546         return 0;
 547 }
 548
 549 static int diff_cache(struct rev_info *revs,
 550                       const struct object_id *tree_oid,
 551                       const char *tree_name,
 552                       int cached)
 553 {
 554         struct tree *tree;
 555         struct tree_desc t;
 556         struct unpack_trees_options opts;
 557
 558         tree = parse_tree_indirect(tree_oid);
 559         if (!tree)
 560                 return error("bad tree object %s",
 561                              tree_name ? tree_name : oid_to_hex(tree_oid));
 562         memset(&opts, 0, sizeof(opts));
 563         opts.head_idx = 1;
 564         opts.index_only = cached;
 565         opts.diff_index_cached = (cached &&
 566                                   !revs->diffopt.flags.find_copies_harder);
 567         opts.merge = 1;
 568         opts.fn = oneway_diff;
 569         opts.unpack_data = revs;
 570         opts.src_index = revs->diffopt.repo->index;
 571         opts.dst_index = NULL;
 572         opts.pathspec = &revs->diffopt.pathspec;
 573         opts.pathspec->recursive = 1;
 574
 575         init_tree_desc(&t, &tree->object.oid, tree->buffer, tree->size);
 576         return unpack_trees(1, &t, &opts);
 577 }
 578
 579 void diff_get_merge_base(const struct rev_info *revs, struct object_id *mb)
 580 {
 581         int i;
 582         struct commit *mb_child[2] = {0};
 583         struct commit_list *merge_bases = NULL;
 584
 585         for (i = 0; i < revs->pending.nr; i++) {
 586                 struct object *obj = revs->pending.objects[i].item;
 587                 if (obj->flags)
 588                         die(_("--merge-base does not work with ranges"));
 589         }
 590
 591         /*
 592          * This check must go after the for loop above because A...B
 593          * ranges produce three pending commits, resulting in a
 594          * misleading error message.
 595          */
 596         if (revs->pending.nr < 1 || revs->pending.nr > 2)
 597                 BUG("unexpected revs->pending.nr: %d", revs->pending.nr);
 598
 599         for (i = 0; i < revs->pending.nr; i++)
 600                 mb_child[i] = lookup_commit_reference(the_repository, &revs->pending.objects[i].item->oid);
 601         if (revs->pending.nr == 1) {
 602                 struct object_id oid;
 603
 604                 if (repo_get_oid(the_repository, "HEAD", &oid))
 605                         die(_("unable to get HEAD"));
 606
 607                 mb_child[1] = lookup_commit_reference(the_repository, &oid);
 608         }
 609
 610         if (repo_get_merge_bases(the_repository, mb_child[0], mb_child[1], &merge_bases) < 0)
 611                 exit(128);
 612         if (!merge_bases)
 613                 die(_("no merge base found"));
 614         if (merge_bases->next)
 615                 die(_("multiple merge bases found"));
 616
 617         oidcpy(mb, &merge_bases->item->object.oid);
 618
 619         free_commit_list(merge_bases);
 620 }
 621
 622 void run_diff_index(struct rev_info *revs, unsigned int option)
 623 {
 624         struct object_array_entry *ent;
 625         int cached = !!(option & DIFF_INDEX_CACHED);
 626         int merge_base = !!(option & DIFF_INDEX_MERGE_BASE);
 627         struct object_id oid;
 628         const char *name;
 629         char merge_base_hex[GIT_MAX_HEXSZ + 1];
 630         struct index_state *istate = revs->diffopt.repo->index;
 631
 632         if (revs->pending.nr != 1)
 633                 BUG("run_diff_index must be passed exactly one tree");
 634
 635         trace_performance_enter();
 636         ent = revs->pending.objects;
 637
 638         refresh_fsmonitor(istate);
 639
 640         if (merge_base) {
 641                 diff_get_merge_base(revs, &oid);
 642                 name = oid_to_hex_r(merge_base_hex, &oid);
 643         } else {
 644                 oidcpy(&oid, &ent->item->oid);
 645                 name = ent->name;
 646         }
 647
 648         if (diff_cache(revs, &oid, name, cached))
 649                 exit(128);
 650
 651         diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
 652         diffcore_fix_diff_index();
 653         diffcore_std(&revs->diffopt);
 654         diff_flush(&revs->diffopt);
 655         trace_performance_leave("diff-index");
 656 }
 657
 658 int do_diff_cache(const struct object_id *tree_oid, struct diff_options *opt)
 659 {
 660         struct rev_info revs;
 661
 662         repo_init_revisions(opt->repo, &revs, NULL);
 663         copy_pathspec(&revs.prune_data, &opt->pathspec);
 664         revs.diffopt = *opt;
 665
 666         if (diff_cache(&revs, tree_oid, NULL, 1))
 667                 exit(128);
 668         release_revisions(&revs);
 669         return 0;
 670 }
 671
 672 int index_differs_from(struct repository *r,
 673                        const char *def, const struct diff_flags *flags,
 674                        int ita_invisible_in_index)
 675 {
 676         struct rev_info rev;
 677         struct setup_revision_opt opt;
 678         unsigned has_changes;
 679
 680         repo_init_revisions(r, &rev, NULL);
 681         memset(&opt, 0, sizeof(opt));
 682         opt.def = def;
 683         setup_revisions(0, NULL, &rev, &opt);
 684         rev.diffopt.flags.quick = 1;
 685         rev.diffopt.flags.exit_with_status = 1;
 686         if (flags) {
 687                 diff_flags_or(&rev.diffopt.flags, flags);
 688                 /*
 689                  * Now that flags are merged, honor override_submodule_config
 690                  * and ignore_submodules from passed flags.
 691                  */
 692                 if (flags->override_submodule_config)
 693                         rev.diffopt.flags.ignore_submodules = flags->ignore_submodules;
 694         }
 695         rev.diffopt.ita_invisible_in_index = ita_invisible_in_index;
 696         run_diff_index(&rev, DIFF_INDEX_CACHED);
 697         has_changes = rev.diffopt.flags.has_changes;
 698         release_revisions(&rev);
 699         return (has_changes != 0);
 700 }
 701
 702 static struct strbuf *idiff_prefix_cb(struct diff_options *opt UNUSED, void *data)
 703 {
 704         return data;
 705 }
 706
 707 void show_interdiff(const struct object_id *oid1, const struct object_id *oid2,
 708                     int indent, struct diff_options *diffopt)
 709 {
 710         struct diff_options opts;
 711         struct strbuf prefix = STRBUF_INIT;
 712
 713         memcpy(&opts, diffopt, sizeof(opts));
 714         opts.output_format = DIFF_FORMAT_PATCH;
 715         opts.output_prefix = idiff_prefix_cb;
 716         strbuf_addchars(&prefix, ' ', indent);
 717         opts.output_prefix_data = &prefix;
 718         diff_setup_done(&opts);
 719
 720         diff_tree_oid(oid1, oid2, "", &opts);
 721         diffcore_std(&opts);
 722         diff_flush(&opts);
 723
 724         strbuf_release(&prefix);
 725 }