diff-lib.c

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