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