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 "revision.h"
  10 #include "cache-tree.h"
  11 #include "unpack-trees.h"
  12 #include "refs.h"
  13 #include "submodule.h"
  14 #include "dir.h"
  15 #include "fsmonitor.h"
  16
  17 /*
  18  * diff-files
  19  */
  20
  21 /*
  22  * Has the work tree entity been removed?
  23  *
  24  * Return 1 if it was removed from the work tree, 0 if an entity to be
  25  * compared with the cache entry ce still exists (the latter includes
  26  * the case where a directory that is not a submodule repository
  27  * exists for ce that is a submodule -- it is a submodule that is not
  28  * checked out).  Return negative for an error.
  29  */
  30 static int check_removed(const struct cache_entry *ce, struct stat *st)
  31 {
  32         if (lstat(ce->name, st) < 0) {
  33                 if (!is_missing_file_error(errno))
  34                         return -1;
  35                 return 1;
  36         }
  37         if (has_symlink_leading_path(ce->name, ce_namelen(ce)))
  38                 return 1;
  39         if (S_ISDIR(st->st_mode)) {
  40                 struct object_id sub;
  41
  42                 /*
  43                  * If ce is already a gitlink, we can have a plain
  44                  * directory (i.e. the submodule is not checked out),
  45                  * or a checked out submodule.  Either case this is not
  46                  * a case where something was removed from the work tree,
  47                  * so we will return 0.
  48                  *
  49                  * Otherwise, if the directory is not a submodule
  50                  * repository, that means ce which was a blob turned into
  51                  * a directory --- the blob was removed!
  52                  */
  53                 if (!S_ISGITLINK(ce->ce_mode) &&
  54                     resolve_gitlink_ref(ce->name, "HEAD", &sub))
  55                         return 1;
  56         }
  57         return 0;
  58 }
  59
  60 /*
  61  * Has a file changed or has a submodule new commits or a dirty work tree?
  62  *
  63  * Return 1 when changes are detected, 0 otherwise. If the DIRTY_SUBMODULES
  64  * option is set, the caller does not only want to know if a submodule is
  65  * modified at all but wants to know all the conditions that are met (new
  66  * commits, untracked content and/or modified content).
  67  */
  68 static int match_stat_with_submodule(struct diff_options *diffopt,
  69                                      const struct cache_entry *ce,
  70                                      struct stat *st, unsigned ce_option,
  71                                      unsigned *dirty_submodule)
  72 {
  73         int changed = ie_match_stat(diffopt->repo->index, ce, st, ce_option);
  74         if (S_ISGITLINK(ce->ce_mode)) {
  75                 struct diff_flags orig_flags = diffopt->flags;
  76                 if (!diffopt->flags.override_submodule_config)
  77                         set_diffopt_flags_from_submodule_config(diffopt, ce->name);
  78                 if (diffopt->flags.ignore_submodules)
  79                         changed = 0;
  80                 else if (!diffopt->flags.ignore_dirty_submodules &&
  81                          (!changed || diffopt->flags.dirty_submodules))
  82                         *dirty_submodule = is_submodule_modified(ce->name,
  83                                                                  diffopt->flags.ignore_untracked_in_submodules);
  84                 diffopt->flags = orig_flags;
  85         }
  86         return changed;
  87 }
  88
  89 int run_diff_files(struct rev_info *revs, unsigned int option)
  90 {
  91         int entries, i;
  92         int diff_unmerged_stage = revs->max_count;
  93         unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
  94                               ? CE_MATCH_RACY_IS_DIRTY : 0);
  95         uint64_t start = getnanotime();
  96         struct index_state *istate = revs->diffopt.repo->index;
  97
  98         diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
  99
 100         if (diff_unmerged_stage < 0)
 101                 diff_unmerged_stage = 2;
 102         entries = istate->cache_nr;
 103         for (i = 0; i < entries; i++) {
 104                 unsigned int oldmode, newmode;
 105                 struct cache_entry *ce = istate->cache[i];
 106                 int changed;
 107                 unsigned dirty_submodule = 0;
 108                 const struct object_id *old_oid, *new_oid;
 109
 110                 if (diff_can_quit_early(&revs->diffopt))
 111                         break;
 112
 113                 if (!ce_path_match(istate, ce, &revs->prune_data, NULL))
 114                         continue;
 115
 116                 if (ce_stage(ce)) {
 117                         struct combine_diff_path *dpath;
 118                         struct diff_filepair *pair;
 119                         unsigned int wt_mode = 0;
 120                         int num_compare_stages = 0;
 121                         size_t path_len;
 122                         struct stat st;
 123
 124                         path_len = ce_namelen(ce);
 125
 126                         dpath = xmalloc(combine_diff_path_size(5, path_len));
 127                         dpath->path = (char *) &(dpath->parent[5]);
 128
 129                         dpath->next = NULL;
 130                         memcpy(dpath->path, ce->name, path_len);
 131                         dpath->path[path_len] = '\0';
 132                         oidclr(&dpath->oid);
 133                         memset(&(dpath->parent[0]), 0,
 134                                sizeof(struct combine_diff_parent)*5);
 135
 136                         changed = check_removed(ce, &st);
 137                         if (!changed)
 138                                 wt_mode = ce_mode_from_stat(ce, st.st_mode);
 139                         else {
 140                                 if (changed < 0) {
 141                                         perror(ce->name);
 142                                         continue;
 143                                 }
 144                                 wt_mode = 0;
 145                         }
 146                         dpath->mode = wt_mode;
 147
 148                         while (i < entries) {
 149                                 struct cache_entry *nce = istate->cache[i];
 150                                 int stage;
 151
 152                                 if (strcmp(ce->name, nce->name))
 153                                         break;
 154
 155                                 /* Stage #2 (ours) is the first parent,
 156                                  * stage #3 (theirs) is the second.
 157                                  */
 158                                 stage = ce_stage(nce);
 159                                 if (2 <= stage) {
 160                                         int mode = nce->ce_mode;
 161                                         num_compare_stages++;
 162                                         oidcpy(&dpath->parent[stage - 2].oid,
 163                                                &nce->oid);
 164                                         dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
 165                                         dpath->parent[stage-2].status =
 166                                                 DIFF_STATUS_MODIFIED;
 167                                 }
 168
 169                                 /* diff against the proper unmerged stage */
 170                                 if (stage == diff_unmerged_stage)
 171                                         ce = nce;
 172                                 i++;
 173                         }
 174                         /*
 175                          * Compensate for loop update
 176                          */
 177                         i--;
 178
 179                         if (revs->combine_merges && num_compare_stages == 2) {
 180                                 show_combined_diff(dpath, 2,
 181                                                    revs->dense_combined_merges,
 182                                                    revs);
 183                                 free(dpath);
 184                                 continue;
 185                         }
 186                         FREE_AND_NULL(dpath);
 187
 188                         /*
 189                          * Show the diff for the 'ce' if we found the one
 190                          * from the desired stage.
 191                          */
 192                         pair = diff_unmerge(&revs->diffopt, ce->name);
 193                         if (wt_mode)
 194                                 pair->two->mode = wt_mode;
 195                         if (ce_stage(ce) != diff_unmerged_stage)
 196                                 continue;
 197                 }
 198
 199                 if (ce_uptodate(ce) || ce_skip_worktree(ce))
 200                         continue;
 201
 202                 /* If CE_VALID is set, don't look at workdir for file removal */
 203                 if (ce->ce_flags & CE_VALID) {
 204                         changed = 0;
 205                         newmode = ce->ce_mode;
 206                 } else {
 207                         struct stat st;
 208
 209                         changed = check_removed(ce, &st);
 210                         if (changed) {
 211                                 if (changed < 0) {
 212                                         perror(ce->name);
 213                                         continue;
 214                                 }
 215                                 diff_addremove(&revs->diffopt, '-', ce->ce_mode,
 216                                                &ce->oid,
 217                                                !is_null_oid(&ce->oid),
 218                                                ce->name, 0);
 219                                 continue;
 220                         } else if (revs->diffopt.ita_invisible_in_index &&
 221                                    ce_intent_to_add(ce)) {
 222                                 diff_addremove(&revs->diffopt, '+', ce->ce_mode,
 223                                                the_hash_algo->empty_tree, 0,
 224                                                ce->name, 0);
 225                                 continue;
 226                         }
 227
 228                         changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
 229                                                             ce_option, &dirty_submodule);
 230                         newmode = ce_mode_from_stat(ce, st.st_mode);
 231                 }
 232
 233                 if (!changed && !dirty_submodule) {
 234                         ce_mark_uptodate(ce);
 235                         mark_fsmonitor_valid(istate, ce);
 236                         if (!revs->diffopt.flags.find_copies_harder)
 237                                 continue;
 238                 }
 239                 oldmode = ce->ce_mode;
 240                 old_oid = &ce->oid;
 241                 new_oid = changed ? &null_oid : &ce->oid;
 242                 diff_change(&revs->diffopt, oldmode, newmode,
 243                             old_oid, new_oid,
 244                             !is_null_oid(old_oid),
 245                             !is_null_oid(new_oid),
 246                             ce->name, 0, dirty_submodule);
 247
 248         }
 249         diffcore_std(&revs->diffopt);
 250         diff_flush(&revs->diffopt);
 251         trace_performance_since(start, "diff-files");
 252         return 0;
 253 }
 254
 255 /*
 256  * diff-index
 257  */
 258
 259 /* A file entry went away or appeared */
 260 static void diff_index_show_file(struct rev_info *revs,
 261                                  const char *prefix,
 262                                  const struct cache_entry *ce,
 263                                  const struct object_id *oid, int oid_valid,
 264                                  unsigned int mode,
 265                                  unsigned dirty_submodule)
 266 {
 267         diff_addremove(&revs->diffopt, prefix[0], mode,
 268                        oid, oid_valid, ce->name, dirty_submodule);
 269 }
 270
 271 static int get_stat_data(const struct cache_entry *ce,
 272                          const struct object_id **oidp,
 273                          unsigned int *modep,
 274                          int cached, int match_missing,
 275                          unsigned *dirty_submodule, struct diff_options *diffopt)
 276 {
 277         const struct object_id *oid = &ce->oid;
 278         unsigned int mode = ce->ce_mode;
 279
 280         if (!cached && !ce_uptodate(ce)) {
 281                 int changed;
 282                 struct stat st;
 283                 changed = check_removed(ce, &st);
 284                 if (changed < 0)
 285                         return -1;
 286                 else if (changed) {
 287                         if (match_missing) {
 288                                 *oidp = oid;
 289                                 *modep = mode;
 290                                 return 0;
 291                         }
 292                         return -1;
 293                 }
 294                 changed = match_stat_with_submodule(diffopt, ce, &st,
 295                                                     0, dirty_submodule);
 296                 if (changed) {
 297                         mode = ce_mode_from_stat(ce, st.st_mode);
 298                         oid = &null_oid;
 299                 }
 300         }
 301
 302         *oidp = oid;
 303         *modep = mode;
 304         return 0;
 305 }
 306
 307 static void show_new_file(struct rev_info *revs,
 308                           const struct cache_entry *new_file,
 309                           int cached, int match_missing)
 310 {
 311         const struct object_id *oid;
 312         unsigned int mode;
 313         unsigned dirty_submodule = 0;
 314
 315         /*
 316          * New file in the index: it might actually be different in
 317          * the working tree.
 318          */
 319         if (get_stat_data(new_file, &oid, &mode, cached, match_missing,
 320             &dirty_submodule, &revs->diffopt) < 0)
 321                 return;
 322
 323         diff_index_show_file(revs, "+", new_file, oid, !is_null_oid(oid), mode, dirty_submodule);
 324 }
 325
 326 static int show_modified(struct rev_info *revs,
 327                          const struct cache_entry *old_entry,
 328                          const struct cache_entry *new_entry,
 329                          int report_missing,
 330                          int cached, int match_missing)
 331 {
 332         unsigned int mode, oldmode;
 333         const struct object_id *oid;
 334         unsigned dirty_submodule = 0;
 335
 336         if (get_stat_data(new_entry, &oid, &mode, cached, match_missing,
 337                           &dirty_submodule, &revs->diffopt) < 0) {
 338                 if (report_missing)
 339                         diff_index_show_file(revs, "-", old_entry,
 340                                              &old_entry->oid, 1, old_entry->ce_mode,
 341                                              0);
 342                 return -1;
 343         }
 344
 345         if (revs->combine_merges && !cached &&
 346             (!oideq(oid, &old_entry->oid) || !oideq(&old_entry->oid, &new_entry->oid))) {
 347                 struct combine_diff_path *p;
 348                 int pathlen = ce_namelen(new_entry);
 349
 350                 p = xmalloc(combine_diff_path_size(2, pathlen));
 351                 p->path = (char *) &p->parent[2];
 352                 p->next = NULL;
 353                 memcpy(p->path, new_entry->name, pathlen);
 354                 p->path[pathlen] = 0;
 355                 p->mode = mode;
 356                 oidclr(&p->oid);
 357                 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
 358                 p->parent[0].status = DIFF_STATUS_MODIFIED;
 359                 p->parent[0].mode = new_entry->ce_mode;
 360                 oidcpy(&p->parent[0].oid, &new_entry->oid);
 361                 p->parent[1].status = DIFF_STATUS_MODIFIED;
 362                 p->parent[1].mode = old_entry->ce_mode;
 363                 oidcpy(&p->parent[1].oid, &old_entry->oid);
 364                 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
 365                 free(p);
 366                 return 0;
 367         }
 368
 369         oldmode = old_entry->ce_mode;
 370         if (mode == oldmode && oideq(oid, &old_entry->oid) && !dirty_submodule &&
 371             !revs->diffopt.flags.find_copies_harder)
 372                 return 0;
 373
 374         diff_change(&revs->diffopt, oldmode, mode,
 375                     &old_entry->oid, oid, 1, !is_null_oid(oid),
 376                     old_entry->name, 0, dirty_submodule);
 377         return 0;
 378 }
 379
 380 /*
 381  * This gets a mix of an existing index and a tree, one pathname entry
 382  * at a time. The index entry may be a single stage-0 one, but it could
 383  * also be multiple unmerged entries (in which case idx_pos/idx_nr will
 384  * give you the position and number of entries in the index).
 385  */
 386 static void do_oneway_diff(struct unpack_trees_options *o,
 387                            const struct cache_entry *idx,
 388                            const struct cache_entry *tree)
 389 {
 390         struct rev_info *revs = o->unpack_data;
 391         int match_missing, cached;
 392
 393         /*
 394          * i-t-a entries do not actually exist in the index (if we're
 395          * looking at its content)
 396          */
 397         if (o->index_only &&
 398             revs->diffopt.ita_invisible_in_index &&
 399             idx && ce_intent_to_add(idx)) {
 400                 idx = NULL;
 401                 if (!tree)
 402                         return; /* nothing to diff.. */
 403         }
 404
 405         /* if the entry is not checked out, don't examine work tree */
 406         cached = o->index_only ||
 407                 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
 408         /*
 409          * Backward compatibility wart - "diff-index -m" does
 410          * not mean "do not ignore merges", but "match_missing".
 411          *
 412          * But with the revision flag parsing, that's found in
 413          * "!revs->ignore_merges".
 414          */
 415         match_missing = !revs->ignore_merges;
 416
 417         if (cached && idx && ce_stage(idx)) {
 418                 struct diff_filepair *pair;
 419                 pair = diff_unmerge(&revs->diffopt, idx->name);
 420                 if (tree)
 421                         fill_filespec(pair->one, &tree->oid, 1,
 422                                       tree->ce_mode);
 423                 return;
 424         }
 425
 426         /*
 427          * Something added to the tree?
 428          */
 429         if (!tree) {
 430                 show_new_file(revs, idx, cached, match_missing);
 431                 return;
 432         }
 433
 434         /*
 435          * Something removed from the tree?
 436          */
 437         if (!idx) {
 438                 diff_index_show_file(revs, "-", tree, &tree->oid, 1,
 439                                      tree->ce_mode, 0);
 440                 return;
 441         }
 442
 443         /* Show difference between old and new */
 444         show_modified(revs, tree, idx, 1, cached, match_missing);
 445 }
 446
 447 /*
 448  * The unpack_trees() interface is designed for merging, so
 449  * the different source entries are designed primarily for
 450  * the source trees, with the old index being really mainly
 451  * used for being replaced by the result.
 452  *
 453  * For diffing, the index is more important, and we only have a
 454  * single tree.
 455  *
 456  * We're supposed to advance o->pos to skip what we have already processed.
 457  *
 458  * This wrapper makes it all more readable, and takes care of all
 459  * the fairly complex unpack_trees() semantic requirements, including
 460  * the skipping, the path matching, the type conflict cases etc.
 461  */
 462 static int oneway_diff(const struct cache_entry * const *src,
 463                        struct unpack_trees_options *o)
 464 {
 465         const struct cache_entry *idx = src[0];
 466         const struct cache_entry *tree = src[1];
 467         struct rev_info *revs = o->unpack_data;
 468
 469         /*
 470          * Unpack-trees generates a DF/conflict entry if
 471          * there was a directory in the index and a tree
 472          * in the tree. From a diff standpoint, that's a
 473          * delete of the tree and a create of the file.
 474          */
 475         if (tree == o->df_conflict_entry)
 476                 tree = NULL;
 477
 478         if (ce_path_match(revs->diffopt.repo->index,
 479                           idx ? idx : tree,
 480                           &revs->prune_data, NULL)) {
 481                 do_oneway_diff(o, idx, tree);
 482                 if (diff_can_quit_early(&revs->diffopt)) {
 483                         o->exiting_early = 1;
 484                         return -1;
 485                 }
 486         }
 487
 488         return 0;
 489 }
 490
 491 static int diff_cache(struct rev_info *revs,
 492                       const struct object_id *tree_oid,
 493                       const char *tree_name,
 494                       int cached)
 495 {
 496         struct tree *tree;
 497         struct tree_desc t;
 498         struct unpack_trees_options opts;
 499
 500         tree = parse_tree_indirect(tree_oid);
 501         if (!tree)
 502                 return error("bad tree object %s",
 503                              tree_name ? tree_name : oid_to_hex(tree_oid));
 504         memset(&opts, 0, sizeof(opts));
 505         opts.head_idx = 1;
 506         opts.index_only = cached;
 507         opts.diff_index_cached = (cached &&
 508                                   !revs->diffopt.flags.find_copies_harder);
 509         opts.merge = 1;
 510         opts.fn = oneway_diff;
 511         opts.unpack_data = revs;
 512         opts.src_index = revs->diffopt.repo->index;
 513         opts.dst_index = NULL;
 514         opts.pathspec = &revs->diffopt.pathspec;
 515         opts.pathspec->recursive = 1;
 516
 517         init_tree_desc(&t, tree->buffer, tree->size);
 518         return unpack_trees(1, &t, &opts);
 519 }
 520
 521 int run_diff_index(struct rev_info *revs, int cached)
 522 {
 523         struct object_array_entry *ent;
 524
 525         if (revs->pending.nr != 1)
 526                 BUG("run_diff_index must be passed exactly one tree");
 527
 528         trace_performance_enter();
 529         ent = revs->pending.objects;
 530         if (diff_cache(revs, &ent->item->oid, ent->name, cached))
 531                 exit(128);
 532
 533         diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
 534         diffcore_fix_diff_index();
 535         diffcore_std(&revs->diffopt);
 536         diff_flush(&revs->diffopt);
 537         trace_performance_leave("diff-index");
 538         return 0;
 539 }
 540
 541 int do_diff_cache(const struct object_id *tree_oid, struct diff_options *opt)
 542 {
 543         struct rev_info revs;
 544
 545         repo_init_revisions(opt->repo, &revs, NULL);
 546         copy_pathspec(&revs.prune_data, &opt->pathspec);
 547         revs.diffopt = *opt;
 548
 549         if (diff_cache(&revs, tree_oid, NULL, 1))
 550                 exit(128);
 551         return 0;
 552 }
 553
 554 int index_differs_from(struct repository *r,
 555                        const char *def, const struct diff_flags *flags,
 556                        int ita_invisible_in_index)
 557 {
 558         struct rev_info rev;
 559         struct setup_revision_opt opt;
 560
 561         repo_init_revisions(r, &rev, NULL);
 562         memset(&opt, 0, sizeof(opt));
 563         opt.def = def;
 564         setup_revisions(0, NULL, &rev, &opt);
 565         rev.diffopt.flags.quick = 1;
 566         rev.diffopt.flags.exit_with_status = 1;
 567         if (flags)
 568                 diff_flags_or(&rev.diffopt.flags, flags);
 569         rev.diffopt.ita_invisible_in_index = ita_invisible_in_index;
 570         run_diff_index(&rev, 1);
 571         object_array_clear(&rev.pending);
 572         return (rev.diffopt.flags.has_changes != 0);
 573 }