diff-lib.c

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