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