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