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                         if (revs->diffopt.flags.find_copies_harder)
 231                                 diff_same(&revs->diffopt, ce->ce_mode,
 232                                           &ce->oid, ce->name);
 233                         continue;
 234                 }
 235
 236                 /*
 237                  * When CE_VALID is set (via "update-index --assume-unchanged"
 238                  * or via adding paths while core.ignorestat is set to true),
 239                  * the user has promised that the working tree file for that
 240                  * path will not be modified.  When CE_FSMONITOR_VALID is true,
 241                  * the fsmonitor knows that the path hasn't been modified since
 242                  * we refreshed the cached stat information.  In either case,
 243                  * we do not have to stat to see if the path has been removed
 244                  * or modified.
 245                  */
 246                 if (ce->ce_flags & (CE_VALID | CE_FSMONITOR_VALID)) {
 247                         changed = 0;
 248                         newmode = ce->ce_mode;
 249                 } else {
 250                         struct stat st;
 251
 252                         changed = check_removed(ce, &st);
 253                         if (changed) {
 254                                 if (changed < 0) {
 255                                         perror(ce->name);
 256                                         continue;
 257                                 }
 258                                 diff_addremove(&revs->diffopt, '-', ce->ce_mode,
 259                                                &ce->oid,
 260                                                !is_null_oid(&ce->oid),
 261                                                ce->name, 0);
 262                                 continue;
 263                         } else if (revs->diffopt.ita_invisible_in_index &&
 264                                    ce_intent_to_add(ce)) {
 265                                 newmode = ce_mode_from_stat(ce, st.st_mode);
 266                                 diff_addremove(&revs->diffopt, '+', newmode,
 267                                                null_oid(the_hash_algo), 0, ce->name, 0);
 268                                 continue;
 269                         }
 270
 271                         changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
 272                                                             ce_option, &dirty_submodule);
 273                         newmode = ce_mode_from_stat(ce, st.st_mode);
 274                 }
 275
 276                 if (!changed && !dirty_submodule) {
 277                         ce_mark_uptodate(ce);
 278                         mark_fsmonitor_valid(istate, ce);
 279                         if (revs->diffopt.flags.find_copies_harder)
 280                                 diff_same(&revs->diffopt, newmode,
 281                                           &ce->oid, ce->name);
 282                         continue;
 283                 }
 284                 oldmode = ce->ce_mode;
 285                 old_oid = &ce->oid;
 286                 new_oid = changed ? null_oid(the_hash_algo) : &ce->oid;
 287                 diff_change(&revs->diffopt, oldmode, newmode,
 288                             old_oid, new_oid,
 289                             !is_null_oid(old_oid),
 290                             !is_null_oid(new_oid),
 291                             ce->name, 0, dirty_submodule);
 292
 293         }
 294         diffcore_std(&revs->diffopt);
 295         diff_flush(&revs->diffopt);
 296         trace_performance_since(start, "diff-files");
 297 }
 298
 299 /*
 300  * diff-index
 301  */
 302
 303 /* A file entry went away or appeared */
 304 static void diff_index_show_file(struct rev_info *revs,
 305                                  const char *prefix,
 306                                  const struct cache_entry *ce,
 307                                  const struct object_id *oid, int oid_valid,
 308                                  unsigned int mode,
 309                                  unsigned dirty_submodule)
 310 {
 311         diff_addremove(&revs->diffopt, prefix[0], mode,
 312                        oid, oid_valid, ce->name, dirty_submodule);
 313 }
 314
 315 static int get_stat_data(const struct cache_entry *ce,
 316                          const struct object_id **oidp,
 317                          unsigned int *modep,
 318                          int cached, int match_missing,
 319                          unsigned *dirty_submodule, struct diff_options *diffopt)
 320 {
 321         const struct object_id *oid = &ce->oid;
 322         unsigned int mode = ce->ce_mode;
 323
 324         if (!cached && !ce_uptodate(ce)) {
 325                 int changed;
 326                 struct stat st;
 327                 changed = check_removed(ce, &st);
 328                 if (changed < 0)
 329                         return -1;
 330                 else if (changed) {
 331                         if (match_missing) {
 332                                 *oidp = oid;
 333                                 *modep = mode;
 334                                 return 0;
 335                         }
 336                         return -1;
 337                 }
 338                 changed = match_stat_with_submodule(diffopt, ce, &st,
 339                                                     0, dirty_submodule);
 340                 if (changed) {
 341                         mode = ce_mode_from_stat(ce, st.st_mode);
 342                         oid = null_oid(the_hash_algo);
 343                 }
 344         }
 345
 346         *oidp = oid;
 347         *modep = mode;
 348         return 0;
 349 }
 350
 351 static void show_new_file(struct rev_info *revs,
 352                           const struct cache_entry *new_file,
 353                           int cached, int match_missing)
 354 {
 355         const struct object_id *oid;
 356         unsigned int mode;
 357         unsigned dirty_submodule = 0;
 358
 359         if (new_file && S_ISSPARSEDIR(new_file->ce_mode)) {
 360                 diff_tree_oid(NULL, &new_file->oid, new_file->name, &revs->diffopt);
 361                 return;
 362         }
 363
 364         /*
 365          * New file in the index: it might actually be different in
 366          * the working tree.
 367          */
 368         if (get_stat_data(new_file, &oid, &mode, cached, match_missing,
 369             &dirty_submodule, &revs->diffopt) < 0)
 370                 return;
 371
 372         diff_index_show_file(revs, "+", new_file, oid, !is_null_oid(oid), mode, dirty_submodule);
 373 }
 374
 375 static int show_modified(struct rev_info *revs,
 376                          const struct cache_entry *old_entry,
 377                          const struct cache_entry *new_entry,
 378                          int report_missing,
 379                          int cached, int match_missing)
 380 {
 381         unsigned int mode, oldmode;
 382         const struct object_id *oid;
 383         unsigned dirty_submodule = 0;
 384
 385         assert(S_ISSPARSEDIR(old_entry->ce_mode) ==
 386                S_ISSPARSEDIR(new_entry->ce_mode));
 387
 388         /*
 389          * If both are sparse directory entries, then expand the
 390          * modifications to the file level. If only one was a sparse
 391          * directory, then they appear as an add and delete instead of
 392          * a modification.
 393          */
 394         if (S_ISSPARSEDIR(new_entry->ce_mode)) {
 395                 diff_tree_oid(&old_entry->oid, &new_entry->oid, new_entry->name, &revs->diffopt);
 396                 return 0;
 397         }
 398
 399         if (get_stat_data(new_entry, &oid, &mode, cached, match_missing,
 400                           &dirty_submodule, &revs->diffopt) < 0) {
 401                 if (report_missing)
 402                         diff_index_show_file(revs, "-", old_entry,
 403                                              &old_entry->oid, 1, old_entry->ce_mode,
 404                                              0);
 405                 return -1;
 406         }
 407
 408         if (revs->combine_merges && !cached &&
 409             (!oideq(oid, &old_entry->oid) || !oideq(&old_entry->oid, &new_entry->oid))) {
 410                 struct combine_diff_path *p;
 411
 412                 p = combine_diff_path_new(new_entry->name,
 413                                           ce_namelen(new_entry),
 414                                           mode, null_oid(the_hash_algo), 2);
 415                 p->parent[0].status = DIFF_STATUS_MODIFIED;
 416                 p->parent[0].mode = new_entry->ce_mode;
 417                 oidcpy(&p->parent[0].oid, &new_entry->oid);
 418                 p->parent[1].status = DIFF_STATUS_MODIFIED;
 419                 p->parent[1].mode = old_entry->ce_mode;
 420                 oidcpy(&p->parent[1].oid, &old_entry->oid);
 421                 show_combined_diff(p, 2, revs);
 422                 free(p);
 423                 return 0;
 424         }
 425
 426         oldmode = old_entry->ce_mode;
 427         if (mode != oldmode || !oideq(oid, &old_entry->oid) || dirty_submodule)
 428                 diff_change(&revs->diffopt, oldmode, mode,
 429                             &old_entry->oid, oid, 1, !is_null_oid(oid),
 430                             old_entry->name, 0, dirty_submodule);
 431         else if (revs->diffopt.flags.find_copies_harder)
 432                 diff_same(&revs->diffopt, mode, oid, old_entry->name);
 433         return 0;
 434 }
 435
 436 /*
 437  * This gets a mix of an existing index and a tree, one pathname entry
 438  * at a time. The index entry may be a single stage-0 one, but it could
 439  * also be multiple unmerged entries (in which case idx_pos/idx_nr will
 440  * give you the position and number of entries in the index).
 441  */
 442 static void do_oneway_diff(struct unpack_trees_options *o,
 443                            const struct cache_entry *idx,
 444                            const struct cache_entry *tree)
 445 {
 446         struct rev_info *revs = o->unpack_data;
 447         int match_missing, cached;
 448
 449         /*
 450          * i-t-a entries do not actually exist in the index (if we're
 451          * looking at its content)
 452          */
 453         if (o->index_only &&
 454             revs->diffopt.ita_invisible_in_index &&
 455             idx && ce_intent_to_add(idx)) {
 456                 idx = NULL;
 457                 if (!tree)
 458                         return; /* nothing to diff.. */
 459         }
 460
 461         /* if the entry is not checked out, don't examine work tree */
 462         cached = o->index_only ||
 463                 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
 464
 465         match_missing = revs->match_missing;
 466
 467         if (cached && idx && ce_stage(idx)) {
 468                 struct diff_filepair *pair;
 469                 pair = diff_unmerge(&revs->diffopt, idx->name);
 470                 if (tree)
 471                         fill_filespec(pair->one, &tree->oid, 1,
 472                                       tree->ce_mode);
 473                 return;
 474         }
 475
 476         /*
 477          * Something added to the tree?
 478          */
 479         if (!tree) {
 480                 show_new_file(revs, idx, cached, match_missing);
 481                 return;
 482         }
 483
 484         /*
 485          * Something removed from the tree?
 486          */
 487         if (!idx) {
 488                 if (S_ISSPARSEDIR(tree->ce_mode)) {
 489                         diff_tree_oid(&tree->oid, NULL, tree->name, &revs->diffopt);
 490                         return;
 491                 }
 492
 493                 diff_index_show_file(revs, "-", tree, &tree->oid, 1,
 494                                      tree->ce_mode, 0);
 495                 return;
 496         }
 497
 498         /* Show difference between old and new */
 499         show_modified(revs, tree, idx, 1, cached, match_missing);
 500 }
 501
 502 /*
 503  * The unpack_trees() interface is designed for merging, so
 504  * the different source entries are designed primarily for
 505  * the source trees, with the old index being really mainly
 506  * used for being replaced by the result.
 507  *
 508  * For diffing, the index is more important, and we only have a
 509  * single tree.
 510  *
 511  * We're supposed to advance o->pos to skip what we have already processed.
 512  *
 513  * This wrapper makes it all more readable, and takes care of all
 514  * the fairly complex unpack_trees() semantic requirements, including
 515  * the skipping, the path matching, the type conflict cases etc.
 516  */
 517 static int oneway_diff(const struct cache_entry * const *src,
 518                        struct unpack_trees_options *o)
 519 {
 520         const struct cache_entry *idx = src[0];
 521         const struct cache_entry *tree = src[1];
 522         struct rev_info *revs = o->unpack_data;
 523
 524         /*
 525          * Unpack-trees generates a DF/conflict entry if
 526          * there was a directory in the index and a tree
 527          * in the tree. From a diff standpoint, that's a
 528          * delete of the tree and a create of the file.
 529          */
 530         if (tree == o->df_conflict_entry)
 531                 tree = NULL;
 532
 533         if (ce_path_match(revs->diffopt.repo->index,
 534                           idx ? idx : tree,
 535                           &revs->prune_data, NULL)) {
 536                 do_oneway_diff(o, idx, tree);
 537                 if (diff_can_quit_early(&revs->diffopt)) {
 538                         o->exiting_early = 1;
 539                         return -1;
 540                 }
 541         }
 542
 543         return 0;
 544 }
 545
 546 static int diff_cache(struct rev_info *revs,
 547                       const struct object_id *tree_oid,
 548                       const char *tree_name,
 549                       int cached)
 550 {
 551         struct tree *tree;
 552         struct tree_desc t;
 553         struct unpack_trees_options opts;
 554
 555         tree = repo_parse_tree_indirect(the_repository, tree_oid);
 556         if (!tree)
 557                 return error("bad tree object %s",
 558                              tree_name ? tree_name : oid_to_hex(tree_oid));
 559         memset(&opts, 0, sizeof(opts));
 560         opts.head_idx = 1;
 561         opts.index_only = cached;
 562         opts.diff_index_cached = (cached &&
 563                                   !revs->diffopt.flags.find_copies_harder);
 564         opts.merge = 1;
 565         opts.fn = oneway_diff;
 566         opts.unpack_data = revs;
 567         opts.src_index = revs->diffopt.repo->index;
 568         opts.dst_index = NULL;
 569         opts.pathspec = &revs->diffopt.pathspec;
 570         opts.pathspec->recursive = 1;
 571         if (revs->diffopt.max_depth_valid)
 572                 die(_("max-depth is not supported for index diffs"));
 573
 574         init_tree_desc(&t, &tree->object.oid, tree->buffer, tree->size);
 575         return unpack_trees(1, &t, &opts);
 576 }
 577
 578 void diff_get_merge_base(const struct rev_info *revs, struct object_id *mb)
 579 {
 580         int i;
 581         struct commit *mb_child[2] = {0};
 582         struct commit_list *merge_bases = NULL;
 583
 584         for (i = 0; i < revs->pending.nr; i++) {
 585                 struct object *obj = revs->pending.objects[i].item;
 586                 if (obj->flags)
 587                         die(_("--merge-base does not work with ranges"));
 588         }
 589
 590         /*
 591          * This check must go after the for loop above because A...B
 592          * ranges produce three pending commits, resulting in a
 593          * misleading error message.
 594          */
 595         if (revs->pending.nr < 1 || revs->pending.nr > 2)
 596                 BUG("unexpected revs->pending.nr: %d", revs->pending.nr);
 597
 598         for (i = 0; i < revs->pending.nr; i++)
 599                 mb_child[i] = lookup_commit_reference(the_repository, &revs->pending.objects[i].item->oid);
 600         if (revs->pending.nr == 1) {
 601                 struct object_id oid;
 602
 603                 if (repo_get_oid(the_repository, "HEAD", &oid))
 604                         die(_("unable to get HEAD"));
 605
 606                 mb_child[1] = lookup_commit_reference(the_repository, &oid);
 607         }
 608
 609         if (repo_get_merge_bases(the_repository, mb_child[0], mb_child[1], &merge_bases) < 0)
 610                 exit(128);
 611         if (!merge_bases)
 612                 die(_("no merge base found"));
 613         if (merge_bases->next)
 614                 die(_("multiple merge bases found"));
 615
 616         oidcpy(mb, &merge_bases->item->object.oid);
 617
 618         commit_list_free(merge_bases);
 619 }
 620
 621 void run_diff_index(struct rev_info *revs, unsigned int option)
 622 {
 623         struct object_array_entry *ent;
 624         int cached = !!(option & DIFF_INDEX_CACHED);
 625         int merge_base = !!(option & DIFF_INDEX_MERGE_BASE);
 626         struct object_id oid;
 627         const char *name;
 628         char merge_base_hex[GIT_MAX_HEXSZ + 1];
 629         struct index_state *istate = revs->diffopt.repo->index;
 630
 631         if (revs->pending.nr != 1)
 632                 BUG("run_diff_index must be passed exactly one tree");
 633
 634         trace_performance_enter();
 635         ent = revs->pending.objects;
 636
 637         refresh_fsmonitor(istate);
 638
 639         if (merge_base) {
 640                 diff_get_merge_base(revs, &oid);
 641                 name = oid_to_hex_r(merge_base_hex, &oid);
 642         } else {
 643                 oidcpy(&oid, &ent->item->oid);
 644                 name = ent->name;
 645         }
 646
 647         if (diff_cache(revs, &oid, name, cached))
 648                 exit(128);
 649
 650         diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
 651         diffcore_fix_diff_index();
 652         diffcore_std(&revs->diffopt);
 653         diff_flush(&revs->diffopt);
 654         trace_performance_leave("diff-index");
 655 }
 656
 657 int do_diff_cache(const struct object_id *tree_oid, struct diff_options *opt)
 658 {
 659         struct rev_info revs;
 660
 661         repo_init_revisions(opt->repo, &revs, NULL);
 662         copy_pathspec(&revs.prune_data, &opt->pathspec);
 663         diff_free(&revs.diffopt);
 664         revs.diffopt = *opt;
 665         revs.diffopt.no_free = 1;
 666
 667         if (diff_cache(&revs, tree_oid, NULL, 1))
 668                 exit(128);
 669
 670         release_revisions(&revs);
 671         return 0;
 672 }
 673
 674 int index_differs_from(struct repository *r,
 675                        const char *def, const struct diff_flags *flags,
 676                        int ita_invisible_in_index)
 677 {
 678         struct rev_info rev;
 679         struct setup_revision_opt opt;
 680         unsigned has_changes;
 681
 682         repo_init_revisions(r, &rev, NULL);
 683         memset(&opt, 0, sizeof(opt));
 684         opt.def = def;
 685         setup_revisions(0, NULL, &rev, &opt);
 686         rev.diffopt.flags.quick = 1;
 687         rev.diffopt.flags.exit_with_status = 1;
 688         if (flags) {
 689                 diff_flags_or(&rev.diffopt.flags, flags);
 690                 /*
 691                  * Now that flags are merged, honor override_submodule_config
 692                  * and ignore_submodules from passed flags.
 693                  */
 694                 if (flags->override_submodule_config)
 695                         rev.diffopt.flags.ignore_submodules = flags->ignore_submodules;
 696         }
 697         rev.diffopt.ita_invisible_in_index = ita_invisible_in_index;
 698         run_diff_index(&rev, DIFF_INDEX_CACHED);
 699         has_changes = rev.diffopt.flags.has_changes;
 700         release_revisions(&rev);
 701         return (has_changes != 0);
 702 }
 703
 704 static const char *idiff_prefix_cb(struct diff_options *opt UNUSED, void *data)
 705 {
 706         return data;
 707 }
 708
 709 void show_interdiff(const struct object_id *oid1, const struct object_id *oid2,
 710                     int indent, struct diff_options *diffopt)
 711 {
 712         struct diff_options opts;
 713         struct strbuf prefix = STRBUF_INIT;
 714
 715         memcpy(&opts, diffopt, sizeof(opts));
 716         opts.output_format = DIFF_FORMAT_PATCH;
 717         opts.output_prefix = idiff_prefix_cb;
 718         strbuf_addchars(&prefix, ' ', indent);
 719         opts.output_prefix_data = prefix.buf;
 720         diff_setup_done(&opts);
 721
 722         diff_tree_oid(oid1, oid2, "", &opts);
 723         diffcore_std(&opts);
 724         diff_flush(&opts);
 725
 726         strbuf_release(&prefix);
 727 }