diff-lib.c

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