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