diff-lib.c

   1 /*
   2  * Copyright (C) 2005 Junio C Hamano
   3  */
   4
   5 #define USE_THE_REPOSITORY_VARIABLE
   6
   7 #include "git-compat-util.h"
   8 #include "commit.h"
   9 #include "diff.h"
  10 #include "diffcore.h"
  11 #include "gettext.h"
  12 #include "hash.h"
  13 #include "hex.h"
  14 #include "object-name.h"
  15 #include "read-cache.h"
  16 #include "revision.h"
  17 #include "cache-tree.h"
  18 #include "unpack-trees.h"
  19 #include "refs.h"
  20 #include "repository.h"
  21 #include "submodule.h"
  22 #include "symlinks.h"
  23 #include "trace.h"
  24 #include "dir.h"
  25 #include "fsmonitor.h"
  26 #include "commit-reach.h"
  27
  28 /*
  29  * diff-files
  30  */
  31
  32 /*
  33  * Has the work tree entity been removed?
  34  *
  35  * Return 1 if it was removed from the work tree, 0 if an entity to be
  36  * compared with the cache entry ce still exists (the latter includes
  37  * the case where a directory that is not a submodule repository
  38  * exists for ce that is a submodule -- it is a submodule that is not
  39  * checked out).  Return negative for an error.
  40  */
  41 static int check_removed(const struct cache_entry *ce, struct stat *st)
  42 {
  43         int stat_err;
  44
  45         if (!(ce->ce_flags & CE_FSMONITOR_VALID))
  46                 stat_err = lstat(ce->name, st);
  47         else
  48                 stat_err = fake_lstat(ce, st);
  49         if (stat_err < 0) {
  50                 if (!is_missing_file_error(errno))
  51                         return -1;
  52                 return 1;
  53         }
  54
  55         if (has_symlink_leading_path(ce->name, ce_namelen(ce)))
  56                 return 1;
  57         if (S_ISDIR(st->st_mode)) {
  58                 struct object_id sub;
  59
  60                 /*
  61                  * If ce is already a gitlink, we can have a plain
  62                  * directory (i.e. the submodule is not checked out),
  63                  * or a checked out submodule.  Either case this is not
  64                  * a case where something was removed from the work tree,
  65                  * so we will return 0.
  66                  *
  67                  * Otherwise, if the directory is not a submodule
  68                  * repository, that means ce which was a blob turned into
  69                  * a directory --- the blob was removed!
  70                  */
  71                 if (!S_ISGITLINK(ce->ce_mode) &&
  72                     repo_resolve_gitlink_ref(the_repository, ce->name,
  73                                              "HEAD", &sub))
  74                         return 1;
  75         }
  76         return 0;
  77 }
  78
  79 /*
  80  * Has a file changed or has a submodule new commits or a dirty work tree?
  81  *
  82  * Return 1 when changes are detected, 0 otherwise. If the DIRTY_SUBMODULES
  83  * option is set, the caller does not only want to know if a submodule is
  84  * modified at all but wants to know all the conditions that are met (new
  85  * commits, untracked content and/or modified content).
  86  */
  87 static int match_stat_with_submodule(struct diff_options *diffopt,
  88                                      const struct cache_entry *ce,
  89                                      struct stat *st, unsigned ce_option,
  90                                      unsigned *dirty_submodule)
  91 {
  92         int changed = ie_match_stat(diffopt->repo->index, ce, st, ce_option);
  93         if (S_ISGITLINK(ce->ce_mode)) {
  94                 struct diff_flags orig_flags = diffopt->flags;
  95                 if (!diffopt->flags.override_submodule_config)
  96                         set_diffopt_flags_from_submodule_config(diffopt, ce->name);
  97                 if (diffopt->flags.ignore_submodules)
  98                         changed = 0;
  99                 else if (!diffopt->flags.ignore_dirty_submodules &&
 100                          (!changed || diffopt->flags.dirty_submodules))
 101                         *dirty_submodule = is_submodule_modified(ce->name,
 102                                                                  diffopt->flags.ignore_untracked_in_submodules);
 103                 diffopt->flags = orig_flags;
 104         }
 105         return changed;
 106 }
 107
 108 void run_diff_files(struct rev_info *revs, unsigned int option)
 109 {
 110         int entries, i;
 111         int diff_unmerged_stage = revs->max_count;
 112         unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
 113                               ? CE_MATCH_RACY_IS_DIRTY : 0);
 114         uint64_t start = getnanotime();
 115         struct index_state *istate = revs->diffopt.repo->index;
 116
 117         diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
 118
 119         refresh_fsmonitor(istate);
 120
 121         if (diff_unmerged_stage < 0)
 122                 diff_unmerged_stage = 2;
 123         entries = istate->cache_nr;
 124         for (i = 0; i < entries; i++) {
 125                 unsigned int oldmode, newmode;
 126                 struct cache_entry *ce = istate->cache[i];
 127                 int changed;
 128                 unsigned dirty_submodule = 0;
 129                 const struct object_id *old_oid, *new_oid;
 130
 131                 if (diff_can_quit_early(&revs->diffopt))
 132                         break;
 133
 134                 /*
 135                  * NEEDSWORK:
 136                  * Here we filter with pathspec but the result is further
 137                  * filtered out when --relative is in effect.  To end-users,
 138                  * a pathspec element that matched only to paths outside the
 139                  * current directory is like not matching anything at all;
 140                  * the handling of ps_matched[] here may become problematic
 141                  * if/when we add the "--error-unmatch" option to "git diff".
 142                  */
 143                 if (!ce_path_match(istate, ce, &revs->prune_data, revs->ps_matched))
 144                         continue;
 145
 146                 if (revs->diffopt.prefix &&
 147                     strncmp(ce->name, revs->diffopt.prefix, revs->diffopt.prefix_length))
 148                         continue;
 149
 150                 if (ce_stage(ce)) {
 151                         struct combine_diff_path *dpath;
 152                         struct diff_filepair *pair;
 153                         unsigned int wt_mode = 0;
 154                         int num_compare_stages = 0;
 155                         size_t path_len;
 156                         struct stat st;
 157
 158                         path_len = ce_namelen(ce);
 159
 160                         dpath = xmalloc(combine_diff_path_size(5, path_len));
 161                         dpath->path = (char *) &(dpath->parent[5]);
 162
 163                         dpath->next = NULL;
 164                         memcpy(dpath->path, ce->name, path_len);
 165                         dpath->path[path_len] = '\0';
 166                         oidclr(&dpath->oid, the_repository->hash_algo);
 167                         memset(&(dpath->parent[0]), 0,
 168                                sizeof(struct combine_diff_parent)*5);
 169
 170                         changed = check_removed(ce, &st);
 171                         if (!changed)
 172                                 wt_mode = ce_mode_from_stat(ce, st.st_mode);
 173                         else {
 174                                 if (changed < 0) {
 175                                         perror(ce->name);
 176                                         continue;
 177                                 }
 178                                 wt_mode = 0;
 179                         }
 180                         dpath->mode = wt_mode;
 181
 182                         while (i < entries) {
 183                                 struct cache_entry *nce = istate->cache[i];
 184                                 int stage;
 185
 186                                 if (strcmp(ce->name, nce->name))
 187                                         break;
 188
 189                                 /* Stage #2 (ours) is the first parent,
 190                                  * stage #3 (theirs) is the second.
 191                                  */
 192                                 stage = ce_stage(nce);
 193                                 if (2 <= stage) {
 194                                         int mode = nce->ce_mode;
 195                                         num_compare_stages++;
 196                                         oidcpy(&dpath->parent[stage - 2].oid,
 197                                                &nce->oid);
 198                                         dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
 199                                         dpath->parent[stage-2].status =
 200                                                 DIFF_STATUS_MODIFIED;
 201                                 }
 202
 203                                 /* diff against the proper unmerged stage */
 204                                 if (stage == diff_unmerged_stage)
 205                                         ce = nce;
 206                                 i++;
 207                         }
 208                         /*
 209                          * Compensate for loop update
 210                          */
 211                         i--;
 212
 213                         if (revs->combine_merges && num_compare_stages == 2) {
 214                                 show_combined_diff(dpath, 2, revs);
 215                                 free(dpath);
 216                                 continue;
 217                         }
 218                         FREE_AND_NULL(dpath);
 219
 220                         /*
 221                          * Show the diff for the 'ce' if we found the one
 222                          * from the desired stage.
 223                          */
 224                         pair = diff_unmerge(&revs->diffopt, ce->name);
 225                         if (wt_mode)
 226                                 pair->two->mode = wt_mode;
 227                         if (ce_stage(ce) != diff_unmerged_stage)
 228                                 continue;
 229                 }
 230
 231                 if (ce_uptodate(ce) || ce_skip_worktree(ce))
 232                         continue;
 233
 234                 /*
 235                  * When CE_VALID is set (via "update-index --assume-unchanged"
 236                  * or via adding paths while core.ignorestat is set to true),
 237                  * the user has promised that the working tree file for that
 238                  * path will not be modified.  When CE_FSMONITOR_VALID is true,
 239                  * the fsmonitor knows that the path hasn't been modified since
 240                  * we refreshed the cached stat information.  In either case,
 241                  * we do not have to stat to see if the path has been removed
 242                  * or modified.
 243                  */
 244                 if (ce->ce_flags & (CE_VALID | CE_FSMONITOR_VALID)) {
 245                         changed = 0;
 246                         newmode = ce->ce_mode;
 247                 } else {
 248                         struct stat st;
 249
 250                         changed = check_removed(ce, &st);
 251                         if (changed) {
 252                                 if (changed < 0) {
 253                                         perror(ce->name);
 254                                         continue;
 255                                 }
 256                                 diff_addremove(&revs->diffopt, '-', ce->ce_mode,
 257                                                &ce->oid,
 258                                                !is_null_oid(&ce->oid),
 259                                                ce->name, 0);
 260                                 continue;
 261                         } else if (revs->diffopt.ita_invisible_in_index &&
 262                                    ce_intent_to_add(ce)) {
 263                                 newmode = ce_mode_from_stat(ce, st.st_mode);
 264                                 diff_addremove(&revs->diffopt, '+', newmode,
 265                                                null_oid(), 0, ce->name, 0);
 266                                 continue;
 267                         }
 268
 269                         changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
 270                                                             ce_option, &dirty_submodule);
 271                         newmode = ce_mode_from_stat(ce, st.st_mode);
 272                 }
 273
 274                 if (!changed && !dirty_submodule) {
 275                         ce_mark_uptodate(ce);
 276                         mark_fsmonitor_valid(istate, ce);
 277                         if (!revs->diffopt.flags.find_copies_harder)
 278                                 continue;
 279                 }
 280                 oldmode = ce->ce_mode;
 281                 old_oid = &ce->oid;
 282                 new_oid = changed ? null_oid() : &ce->oid;
 283                 diff_change(&revs->diffopt, oldmode, newmode,
 284                             old_oid, new_oid,
 285                             !is_null_oid(old_oid),
 286                             !is_null_oid(new_oid),
 287                             ce->name, 0, dirty_submodule);
 288
 289         }
 290         diffcore_std(&revs->diffopt);
 291         diff_flush(&revs->diffopt);
 292         trace_performance_since(start, "diff-files");
 293 }
 294
 295 /*
 296  * diff-index
 297  */
 298
 299 /* A file entry went away or appeared */
 300 static void diff_index_show_file(struct rev_info *revs,
 301                                  const char *prefix,
 302                                  const struct cache_entry *ce,
 303                                  const struct object_id *oid, int oid_valid,
 304                                  unsigned int mode,
 305                                  unsigned dirty_submodule)
 306 {
 307         diff_addremove(&revs->diffopt, prefix[0], mode,
 308                        oid, oid_valid, ce->name, dirty_submodule);
 309 }
 310
 311 static int get_stat_data(const struct index_state *istate,
 312                          const struct cache_entry *ce,
 313                          const struct object_id **oidp,
 314                          unsigned int *modep,
 315                          int cached, int match_missing,
 316                          unsigned *dirty_submodule, struct diff_options *diffopt)
 317 {
 318         const struct object_id *oid = &ce->oid;
 319         unsigned int mode = ce->ce_mode;
 320
 321         if (!cached && !ce_uptodate(ce)) {
 322                 int changed;
 323                 struct stat st;
 324                 changed = check_removed(ce, &st);
 325                 if (changed < 0)
 326                         return -1;
 327                 else if (changed) {
 328                         if (match_missing) {
 329                                 *oidp = oid;
 330                                 *modep = mode;
 331                                 return 0;
 332                         }
 333                         return -1;
 334                 }
 335                 changed = match_stat_with_submodule(diffopt, ce, &st,
 336                                                     0, dirty_submodule);
 337                 if (changed) {
 338                         mode = ce_mode_from_stat(ce, st.st_mode);
 339                         oid = null_oid();
 340                 }
 341         }
 342
 343         *oidp = oid;
 344         *modep = mode;
 345         return 0;
 346 }
 347
 348 static void show_new_file(struct rev_info *revs,
 349                           const struct cache_entry *new_file,
 350                           int cached, int match_missing)
 351 {
 352         const struct object_id *oid;
 353         unsigned int mode;
 354         unsigned dirty_submodule = 0;
 355         struct index_state *istate = revs->diffopt.repo->index;
 356
 357         if (new_file && S_ISSPARSEDIR(new_file->ce_mode)) {
 358                 diff_tree_oid(NULL, &new_file->oid, new_file->name, &revs->diffopt);
 359                 return;
 360         }
 361
 362         /*
 363          * New file in the index: it might actually be different in
 364          * the working tree.
 365          */
 366         if (get_stat_data(istate, new_file, &oid, &mode, cached, match_missing,
 367             &dirty_submodule, &revs->diffopt) < 0)
 368                 return;
 369
 370         diff_index_show_file(revs, "+", new_file, oid, !is_null_oid(oid), mode, dirty_submodule);
 371 }
 372
 373 static int show_modified(struct rev_info *revs,
 374                          const struct cache_entry *old_entry,
 375                          const struct cache_entry *new_entry,
 376                          int report_missing,
 377                          int cached, int match_missing)
 378 {
 379         unsigned int mode, oldmode;
 380         const struct object_id *oid;
 381         unsigned dirty_submodule = 0;
 382         struct index_state *istate = revs->diffopt.repo->index;
 383
 384         assert(S_ISSPARSEDIR(old_entry->ce_mode) ==
 385                S_ISSPARSEDIR(new_entry->ce_mode));
 386
 387         /*
 388          * If both are sparse directory entries, then expand the
 389          * modifications to the file level. If only one was a sparse
 390          * directory, then they appear as an add and delete instead of
 391          * a modification.
 392          */
 393         if (S_ISSPARSEDIR(new_entry->ce_mode)) {
 394                 diff_tree_oid(&old_entry->oid, &new_entry->oid, new_entry->name, &revs->diffopt);
 395                 return 0;
 396         }
 397
 398         if (get_stat_data(istate, new_entry, &oid, &mode, cached, match_missing,
 399                           &dirty_submodule, &revs->diffopt) < 0) {
 400                 if (report_missing)
 401                         diff_index_show_file(revs, "-", old_entry,
 402                                              &old_entry->oid, 1, old_entry->ce_mode,
 403                                              0);
 404                 return -1;
 405         }
 406
 407         if (revs->combine_merges && !cached &&
 408             (!oideq(oid, &old_entry->oid) || !oideq(&old_entry->oid, &new_entry->oid))) {
 409                 struct combine_diff_path *p;
 410                 int pathlen = ce_namelen(new_entry);
 411
 412                 p = xmalloc(combine_diff_path_size(2, pathlen));
 413                 p->path = (char *) &p->parent[2];
 414                 p->next = NULL;
 415                 memcpy(p->path, new_entry->name, pathlen);
 416                 p->path[pathlen] = 0;
 417                 p->mode = mode;
 418                 oidclr(&p->oid, the_repository->hash_algo);
 419                 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
 420                 p->parent[0].status = DIFF_STATUS_MODIFIED;
 421                 p->parent[0].mode = new_entry->ce_mode;
 422                 oidcpy(&p->parent[0].oid, &new_entry->oid);
 423                 p->parent[1].status = DIFF_STATUS_MODIFIED;
 424                 p->parent[1].mode = old_entry->ce_mode;
 425                 oidcpy(&p->parent[1].oid, &old_entry->oid);
 426                 show_combined_diff(p, 2, revs);
 427                 free(p);
 428                 return 0;
 429         }
 430
 431         oldmode = old_entry->ce_mode;
 432         if (mode == oldmode && oideq(oid, &old_entry->oid) && !dirty_submodule &&
 433             !revs->diffopt.flags.find_copies_harder)
 434                 return 0;
 435
 436         diff_change(&revs->diffopt, oldmode, mode,
 437                     &old_entry->oid, oid, 1, !is_null_oid(oid),
 438                     old_entry->name, 0, dirty_submodule);
 439         return 0;
 440 }
 441
 442 /*
 443  * This gets a mix of an existing index and a tree, one pathname entry
 444  * at a time. The index entry may be a single stage-0 one, but it could
 445  * also be multiple unmerged entries (in which case idx_pos/idx_nr will
 446  * give you the position and number of entries in the index).
 447  */
 448 static void do_oneway_diff(struct unpack_trees_options *o,
 449                            const struct cache_entry *idx,
 450                            const struct cache_entry *tree)
 451 {
 452         struct rev_info *revs = o->unpack_data;
 453         int match_missing, cached;
 454
 455         /*
 456          * i-t-a entries do not actually exist in the index (if we're
 457          * looking at its content)
 458          */
 459         if (o->index_only &&
 460             revs->diffopt.ita_invisible_in_index &&
 461             idx && ce_intent_to_add(idx)) {
 462                 idx = NULL;
 463                 if (!tree)
 464                         return; /* nothing to diff.. */
 465         }
 466
 467         /* if the entry is not checked out, don't examine work tree */
 468         cached = o->index_only ||
 469                 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
 470
 471         match_missing = revs->match_missing;
 472
 473         if (cached && idx && ce_stage(idx)) {
 474                 struct diff_filepair *pair;
 475                 pair = diff_unmerge(&revs->diffopt, idx->name);
 476                 if (tree)
 477                         fill_filespec(pair->one, &tree->oid, 1,
 478                                       tree->ce_mode);
 479                 return;
 480         }
 481
 482         /*
 483          * Something added to the tree?
 484          */
 485         if (!tree) {
 486                 show_new_file(revs, idx, cached, match_missing);
 487                 return;
 488         }
 489
 490         /*
 491          * Something removed from the tree?
 492          */
 493         if (!idx) {
 494                 if (S_ISSPARSEDIR(tree->ce_mode)) {
 495                         diff_tree_oid(&tree->oid, NULL, tree->name, &revs->diffopt);
 496                         return;
 497                 }
 498
 499                 diff_index_show_file(revs, "-", tree, &tree->oid, 1,
 500                                      tree->ce_mode, 0);
 501                 return;
 502         }
 503
 504         /* Show difference between old and new */
 505         show_modified(revs, tree, idx, 1, cached, match_missing);
 506 }
 507
 508 /*
 509  * The unpack_trees() interface is designed for merging, so
 510  * the different source entries are designed primarily for
 511  * the source trees, with the old index being really mainly
 512  * used for being replaced by the result.
 513  *
 514  * For diffing, the index is more important, and we only have a
 515  * single tree.
 516  *
 517  * We're supposed to advance o->pos to skip what we have already processed.
 518  *
 519  * This wrapper makes it all more readable, and takes care of all
 520  * the fairly complex unpack_trees() semantic requirements, including
 521  * the skipping, the path matching, the type conflict cases etc.
 522  */
 523 static int oneway_diff(const struct cache_entry * const *src,
 524                        struct unpack_trees_options *o)
 525 {
 526         const struct cache_entry *idx = src[0];
 527         const struct cache_entry *tree = src[1];
 528         struct rev_info *revs = o->unpack_data;
 529
 530         /*
 531          * Unpack-trees generates a DF/conflict entry if
 532          * there was a directory in the index and a tree
 533          * in the tree. From a diff standpoint, that's a
 534          * delete of the tree and a create of the file.
 535          */
 536         if (tree == o->df_conflict_entry)
 537                 tree = NULL;
 538
 539         if (ce_path_match(revs->diffopt.repo->index,
 540                           idx ? idx : tree,
 541                           &revs->prune_data, NULL)) {
 542                 do_oneway_diff(o, idx, tree);
 543                 if (diff_can_quit_early(&revs->diffopt)) {
 544                         o->exiting_early = 1;
 545                         return -1;
 546                 }
 547         }
 548
 549         return 0;
 550 }
 551
 552 static int diff_cache(struct rev_info *revs,
 553                       const struct object_id *tree_oid,
 554                       const char *tree_name,
 555                       int cached)
 556 {
 557         struct tree *tree;
 558         struct tree_desc t;
 559         struct unpack_trees_options opts;
 560
 561         tree = parse_tree_indirect(tree_oid);
 562         if (!tree)
 563                 return error("bad tree object %s",
 564                              tree_name ? tree_name : oid_to_hex(tree_oid));
 565         memset(&opts, 0, sizeof(opts));
 566         opts.head_idx = 1;
 567         opts.index_only = cached;
 568         opts.diff_index_cached = (cached &&
 569                                   !revs->diffopt.flags.find_copies_harder);
 570         opts.merge = 1;
 571         opts.fn = oneway_diff;
 572         opts.unpack_data = revs;
 573         opts.src_index = revs->diffopt.repo->index;
 574         opts.dst_index = NULL;
 575         opts.pathspec = &revs->diffopt.pathspec;
 576         opts.pathspec->recursive = 1;
 577
 578         init_tree_desc(&t, &tree->object.oid, tree->buffer, tree->size);
 579         return unpack_trees(1, &t, &opts);
 580 }
 581
 582 void diff_get_merge_base(const struct rev_info *revs, struct object_id *mb)
 583 {
 584         int i;
 585         struct commit *mb_child[2] = {0};
 586         struct commit_list *merge_bases = NULL;
 587
 588         for (i = 0; i < revs->pending.nr; i++) {
 589                 struct object *obj = revs->pending.objects[i].item;
 590                 if (obj->flags)
 591                         die(_("--merge-base does not work with ranges"));
 592         }
 593
 594         /*
 595          * This check must go after the for loop above because A...B
 596          * ranges produce three pending commits, resulting in a
 597          * misleading error message.
 598          */
 599         if (revs->pending.nr < 1 || revs->pending.nr > 2)
 600                 BUG("unexpected revs->pending.nr: %d", revs->pending.nr);
 601
 602         for (i = 0; i < revs->pending.nr; i++)
 603                 mb_child[i] = lookup_commit_reference(the_repository, &revs->pending.objects[i].item->oid);
 604         if (revs->pending.nr == 1) {
 605                 struct object_id oid;
 606
 607                 if (repo_get_oid(the_repository, "HEAD", &oid))
 608                         die(_("unable to get HEAD"));
 609
 610                 mb_child[1] = lookup_commit_reference(the_repository, &oid);
 611         }
 612
 613         if (repo_get_merge_bases(the_repository, mb_child[0], mb_child[1], &merge_bases) < 0)
 614                 exit(128);
 615         if (!merge_bases)
 616                 die(_("no merge base found"));
 617         if (merge_bases->next)
 618                 die(_("multiple merge bases found"));
 619
 620         oidcpy(mb, &merge_bases->item->object.oid);
 621
 622         free_commit_list(merge_bases);
 623 }
 624
 625 void run_diff_index(struct rev_info *revs, unsigned int option)
 626 {
 627         struct object_array_entry *ent;
 628         int cached = !!(option & DIFF_INDEX_CACHED);
 629         int merge_base = !!(option & DIFF_INDEX_MERGE_BASE);
 630         struct object_id oid;
 631         const char *name;
 632         char merge_base_hex[GIT_MAX_HEXSZ + 1];
 633         struct index_state *istate = revs->diffopt.repo->index;
 634
 635         if (revs->pending.nr != 1)
 636                 BUG("run_diff_index must be passed exactly one tree");
 637
 638         trace_performance_enter();
 639         ent = revs->pending.objects;
 640
 641         refresh_fsmonitor(istate);
 642
 643         if (merge_base) {
 644                 diff_get_merge_base(revs, &oid);
 645                 name = oid_to_hex_r(merge_base_hex, &oid);
 646         } else {
 647                 oidcpy(&oid, &ent->item->oid);
 648                 name = ent->name;
 649         }
 650
 651         if (diff_cache(revs, &oid, name, cached))
 652                 exit(128);
 653
 654         diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
 655         diffcore_fix_diff_index();
 656         diffcore_std(&revs->diffopt);
 657         diff_flush(&revs->diffopt);
 658         trace_performance_leave("diff-index");
 659 }
 660
 661 int do_diff_cache(const struct object_id *tree_oid, struct diff_options *opt)
 662 {
 663         struct rev_info revs;
 664
 665         repo_init_revisions(opt->repo, &revs, NULL);
 666         copy_pathspec(&revs.prune_data, &opt->pathspec);
 667         revs.diffopt = *opt;
 668         revs.diffopt.no_free = 1;
 669
 670         if (diff_cache(&revs, tree_oid, NULL, 1))
 671                 exit(128);
 672
 673         release_revisions(&revs);
 674         return 0;
 675 }
 676
 677 int index_differs_from(struct repository *r,
 678                        const char *def, const struct diff_flags *flags,
 679                        int ita_invisible_in_index)
 680 {
 681         struct rev_info rev;
 682         struct setup_revision_opt opt;
 683         unsigned has_changes;
 684
 685         repo_init_revisions(r, &rev, NULL);
 686         memset(&opt, 0, sizeof(opt));
 687         opt.def = def;
 688         setup_revisions(0, NULL, &rev, &opt);
 689         rev.diffopt.flags.quick = 1;
 690         rev.diffopt.flags.exit_with_status = 1;
 691         if (flags) {
 692                 diff_flags_or(&rev.diffopt.flags, flags);
 693                 /*
 694                  * Now that flags are merged, honor override_submodule_config
 695                  * and ignore_submodules from passed flags.
 696                  */
 697                 if (flags->override_submodule_config)
 698                         rev.diffopt.flags.ignore_submodules = flags->ignore_submodules;
 699         }
 700         rev.diffopt.ita_invisible_in_index = ita_invisible_in_index;
 701         run_diff_index(&rev, DIFF_INDEX_CACHED);
 702         has_changes = rev.diffopt.flags.has_changes;
 703         release_revisions(&rev);
 704         return (has_changes != 0);
 705 }
 706
 707 static struct strbuf *idiff_prefix_cb(struct diff_options *opt UNUSED, void *data)
 708 {
 709         return data;
 710 }
 711
 712 void show_interdiff(const struct object_id *oid1, const struct object_id *oid2,
 713                     int indent, struct diff_options *diffopt)
 714 {
 715         struct diff_options opts;
 716         struct strbuf prefix = STRBUF_INIT;
 717
 718         memcpy(&opts, diffopt, sizeof(opts));
 719         opts.output_format = DIFF_FORMAT_PATCH;
 720         opts.output_prefix = idiff_prefix_cb;
 721         strbuf_addchars(&prefix, ' ', indent);
 722         opts.output_prefix_data = &prefix;
 723         diff_setup_done(&opts);
 724
 725         diff_tree_oid(oid1, oid2, "", &opts);
 726         diffcore_std(&opts);
 727         diff_flush(&opts);
 728
 729         strbuf_release(&prefix);
 730 }