diff-lib.c

   1 /*
   2  * Copyright (C) 2005 Junio C Hamano
   3  */
   4 #include "cache.h"
   5 #include "quote.h"
   6 #include "commit.h"
   7 #include "diff.h"
   8 #include "diffcore.h"
   9 #include "revision.h"
  10 #include "cache-tree.h"
  11 #include "unpack-trees.h"
  12 #include "refs.h"
  13 #include "submodule.h"
  14 #include "dir.h"
  15 #include "fsmonitor.h"
  16
  17 /*
  18  * diff-files
  19  */
  20
  21 /*
  22  * Has the work tree entity been removed?
  23  *
  24  * Return 1 if it was removed from the work tree, 0 if an entity to be
  25  * compared with the cache entry ce still exists (the latter includes
  26  * the case where a directory that is not a submodule repository
  27  * exists for ce that is a submodule -- it is a submodule that is not
  28  * checked out).  Return negative for an error.
  29  */
  30 static int check_removed(const struct cache_entry *ce, struct stat *st)
  31 {
  32         if (lstat(ce->name, st) < 0) {
  33                 if (!is_missing_file_error(errno))
  34                         return -1;
  35                 return 1;
  36         }
  37         if (has_symlink_leading_path(ce->name, ce_namelen(ce)))
  38                 return 1;
  39         if (S_ISDIR(st->st_mode)) {
  40                 struct object_id sub;
  41
  42                 /*
  43                  * If ce is already a gitlink, we can have a plain
  44                  * directory (i.e. the submodule is not checked out),
  45                  * or a checked out submodule.  Either case this is not
  46                  * a case where something was removed from the work tree,
  47                  * so we will return 0.
  48                  *
  49                  * Otherwise, if the directory is not a submodule
  50                  * repository, that means ce which was a blob turned into
  51                  * a directory --- the blob was removed!
  52                  */
  53                 if (!S_ISGITLINK(ce->ce_mode) &&
  54                     resolve_gitlink_ref(ce->name, "HEAD", &sub))
  55                         return 1;
  56         }
  57         return 0;
  58 }
  59
  60 /*
  61  * Has a file changed or has a submodule new commits or a dirty work tree?
  62  *
  63  * Return 1 when changes are detected, 0 otherwise. If the DIRTY_SUBMODULES
  64  * option is set, the caller does not only want to know if a submodule is
  65  * modified at all but wants to know all the conditions that are met (new
  66  * commits, untracked content and/or modified content).
  67  */
  68 static int match_stat_with_submodule(struct diff_options *diffopt,
  69                                      const struct cache_entry *ce,
  70                                      struct stat *st, unsigned ce_option,
  71                                      unsigned *dirty_submodule)
  72 {
  73         int changed = ie_match_stat(diffopt->repo->index, ce, st, ce_option);
  74         if (S_ISGITLINK(ce->ce_mode)) {
  75                 struct diff_flags orig_flags = diffopt->flags;
  76                 if (!diffopt->flags.override_submodule_config)
  77                         set_diffopt_flags_from_submodule_config(diffopt, ce->name);
  78                 if (diffopt->flags.ignore_submodules)
  79                         changed = 0;
  80                 else if (!diffopt->flags.ignore_dirty_submodules &&
  81                          (!changed || diffopt->flags.dirty_submodules))
  82                         *dirty_submodule = is_submodule_modified(ce->name,
  83                                                                  diffopt->flags.ignore_untracked_in_submodules);
  84                 diffopt->flags = orig_flags;
  85         }
  86         return changed;
  87 }
  88
  89 int run_diff_files(struct rev_info *revs, unsigned int option)
  90 {
  91         int entries, i;
  92         int diff_unmerged_stage = revs->max_count;
  93         unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
  94                               ? CE_MATCH_RACY_IS_DIRTY : 0);
  95         uint64_t start = getnanotime();
  96         struct index_state *istate = revs->diffopt.repo->index;
  97
  98         diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
  99
 100         refresh_fsmonitor(istate);
 101
 102         if (diff_unmerged_stage < 0)
 103                 diff_unmerged_stage = 2;
 104         entries = istate->cache_nr;
 105         for (i = 0; i < entries; i++) {
 106                 unsigned int oldmode, newmode;
 107                 struct cache_entry *ce = istate->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(istate, 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 = istate->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, revs);
 183                                 free(dpath);
 184                                 continue;
 185                         }
 186                         FREE_AND_NULL(dpath);
 187
 188                         /*
 189                          * Show the diff for the 'ce' if we found the one
 190                          * from the desired stage.
 191                          */
 192                         pair = diff_unmerge(&revs->diffopt, ce->name);
 193                         if (wt_mode)
 194                                 pair->two->mode = wt_mode;
 195                         if (ce_stage(ce) != diff_unmerged_stage)
 196                                 continue;
 197                 }
 198
 199                 if (ce_uptodate(ce) || ce_skip_worktree(ce))
 200                         continue;
 201
 202                 /*
 203                  * When CE_VALID is set (via "update-index --assume-unchanged"
 204                  * or via adding paths while core.ignorestat is set to true),
 205                  * the user has promised that the working tree file for that
 206                  * path will not be modified.  When CE_FSMONITOR_VALID is true,
 207                  * the fsmonitor knows that the path hasn't been modified since
 208                  * we refreshed the cached stat information.  In either case,
 209                  * we do not have to stat to see if the path has been removed
 210                  * or modified.
 211                  */
 212                 if (ce->ce_flags & (CE_VALID | CE_FSMONITOR_VALID)) {
 213                         changed = 0;
 214                         newmode = ce->ce_mode;
 215                 } else {
 216                         struct stat st;
 217
 218                         changed = check_removed(ce, &st);
 219                         if (changed) {
 220                                 if (changed < 0) {
 221                                         perror(ce->name);
 222                                         continue;
 223                                 }
 224                                 diff_addremove(&revs->diffopt, '-', ce->ce_mode,
 225                                                &ce->oid,
 226                                                !is_null_oid(&ce->oid),
 227                                                ce->name, 0);
 228                                 continue;
 229                         } else if (revs->diffopt.ita_invisible_in_index &&
 230                                    ce_intent_to_add(ce)) {
 231                                 newmode = ce_mode_from_stat(ce, st.st_mode);
 232                                 diff_addremove(&revs->diffopt, '+', newmode,
 233                                                &null_oid, 0, ce->name, 0);
 234                                 continue;
 235                         }
 236
 237                         changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
 238                                                             ce_option, &dirty_submodule);
 239                         newmode = ce_mode_from_stat(ce, st.st_mode);
 240                 }
 241
 242                 if (!changed && !dirty_submodule) {
 243                         ce_mark_uptodate(ce);
 244                         mark_fsmonitor_valid(istate, ce);
 245                         if (!revs->diffopt.flags.find_copies_harder)
 246                                 continue;
 247                 }
 248                 oldmode = ce->ce_mode;
 249                 old_oid = &ce->oid;
 250                 new_oid = changed ? &null_oid : &ce->oid;
 251                 diff_change(&revs->diffopt, oldmode, newmode,
 252                             old_oid, new_oid,
 253                             !is_null_oid(old_oid),
 254                             !is_null_oid(new_oid),
 255                             ce->name, 0, dirty_submodule);
 256
 257         }
 258         diffcore_std(&revs->diffopt);
 259         diff_flush(&revs->diffopt);
 260         trace_performance_since(start, "diff-files");
 261         return 0;
 262 }
 263
 264 /*
 265  * diff-index
 266  */
 267
 268 /* A file entry went away or appeared */
 269 static void diff_index_show_file(struct rev_info *revs,
 270                                  const char *prefix,
 271                                  const struct cache_entry *ce,
 272                                  const struct object_id *oid, int oid_valid,
 273                                  unsigned int mode,
 274                                  unsigned dirty_submodule)
 275 {
 276         diff_addremove(&revs->diffopt, prefix[0], mode,
 277                        oid, oid_valid, ce->name, dirty_submodule);
 278 }
 279
 280 static int get_stat_data(const struct cache_entry *ce,
 281                          const struct object_id **oidp,
 282                          unsigned int *modep,
 283                          int cached, int match_missing,
 284                          unsigned *dirty_submodule, struct diff_options *diffopt)
 285 {
 286         const struct object_id *oid = &ce->oid;
 287         unsigned int mode = ce->ce_mode;
 288
 289         if (!cached && !ce_uptodate(ce)) {
 290                 int changed;
 291                 struct stat st;
 292                 changed = check_removed(ce, &st);
 293                 if (changed < 0)
 294                         return -1;
 295                 else if (changed) {
 296                         if (match_missing) {
 297                                 *oidp = oid;
 298                                 *modep = mode;
 299                                 return 0;
 300                         }
 301                         return -1;
 302                 }
 303                 changed = match_stat_with_submodule(diffopt, ce, &st,
 304                                                     0, dirty_submodule);
 305                 if (changed) {
 306                         mode = ce_mode_from_stat(ce, st.st_mode);
 307                         oid = &null_oid;
 308                 }
 309         }
 310
 311         *oidp = oid;
 312         *modep = mode;
 313         return 0;
 314 }
 315
 316 static void show_new_file(struct rev_info *revs,
 317                           const struct cache_entry *new_file,
 318                           int cached, int match_missing)
 319 {
 320         const struct object_id *oid;
 321         unsigned int mode;
 322         unsigned dirty_submodule = 0;
 323
 324         /*
 325          * New file in the index: it might actually be different in
 326          * the working tree.
 327          */
 328         if (get_stat_data(new_file, &oid, &mode, cached, match_missing,
 329             &dirty_submodule, &revs->diffopt) < 0)
 330                 return;
 331
 332         diff_index_show_file(revs, "+", new_file, oid, !is_null_oid(oid), mode, dirty_submodule);
 333 }
 334
 335 static int show_modified(struct rev_info *revs,
 336                          const struct cache_entry *old_entry,
 337                          const struct cache_entry *new_entry,
 338                          int report_missing,
 339                          int cached, int match_missing)
 340 {
 341         unsigned int mode, oldmode;
 342         const struct object_id *oid;
 343         unsigned dirty_submodule = 0;
 344
 345         if (get_stat_data(new_entry, &oid, &mode, cached, match_missing,
 346                           &dirty_submodule, &revs->diffopt) < 0) {
 347                 if (report_missing)
 348                         diff_index_show_file(revs, "-", old_entry,
 349                                              &old_entry->oid, 1, old_entry->ce_mode,
 350                                              0);
 351                 return -1;
 352         }
 353
 354         if (revs->combine_merges && !cached &&
 355             (!oideq(oid, &old_entry->oid) || !oideq(&old_entry->oid, &new_entry->oid))) {
 356                 struct combine_diff_path *p;
 357                 int pathlen = ce_namelen(new_entry);
 358
 359                 p = xmalloc(combine_diff_path_size(2, pathlen));
 360                 p->path = (char *) &p->parent[2];
 361                 p->next = NULL;
 362                 memcpy(p->path, new_entry->name, pathlen);
 363                 p->path[pathlen] = 0;
 364                 p->mode = mode;
 365                 oidclr(&p->oid);
 366                 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
 367                 p->parent[0].status = DIFF_STATUS_MODIFIED;
 368                 p->parent[0].mode = new_entry->ce_mode;
 369                 oidcpy(&p->parent[0].oid, &new_entry->oid);
 370                 p->parent[1].status = DIFF_STATUS_MODIFIED;
 371                 p->parent[1].mode = old_entry->ce_mode;
 372                 oidcpy(&p->parent[1].oid, &old_entry->oid);
 373                 show_combined_diff(p, 2, revs);
 374                 free(p);
 375                 return 0;
 376         }
 377
 378         oldmode = old_entry->ce_mode;
 379         if (mode == oldmode && oideq(oid, &old_entry->oid) && !dirty_submodule &&
 380             !revs->diffopt.flags.find_copies_harder)
 381                 return 0;
 382
 383         diff_change(&revs->diffopt, oldmode, mode,
 384                     &old_entry->oid, oid, 1, !is_null_oid(oid),
 385                     old_entry->name, 0, dirty_submodule);
 386         return 0;
 387 }
 388
 389 /*
 390  * This gets a mix of an existing index and a tree, one pathname entry
 391  * at a time. The index entry may be a single stage-0 one, but it could
 392  * also be multiple unmerged entries (in which case idx_pos/idx_nr will
 393  * give you the position and number of entries in the index).
 394  */
 395 static void do_oneway_diff(struct unpack_trees_options *o,
 396                            const struct cache_entry *idx,
 397                            const struct cache_entry *tree)
 398 {
 399         struct rev_info *revs = o->unpack_data;
 400         int match_missing, cached;
 401
 402         /*
 403          * i-t-a entries do not actually exist in the index (if we're
 404          * looking at its content)
 405          */
 406         if (o->index_only &&
 407             revs->diffopt.ita_invisible_in_index &&
 408             idx && ce_intent_to_add(idx)) {
 409                 idx = NULL;
 410                 if (!tree)
 411                         return; /* nothing to diff.. */
 412         }
 413
 414         /* if the entry is not checked out, don't examine work tree */
 415         cached = o->index_only ||
 416                 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
 417
 418         match_missing = revs->match_missing;
 419
 420         if (cached && idx && ce_stage(idx)) {
 421                 struct diff_filepair *pair;
 422                 pair = diff_unmerge(&revs->diffopt, idx->name);
 423                 if (tree)
 424                         fill_filespec(pair->one, &tree->oid, 1,
 425                                       tree->ce_mode);
 426                 return;
 427         }
 428
 429         /*
 430          * Something added to the tree?
 431          */
 432         if (!tree) {
 433                 show_new_file(revs, idx, cached, match_missing);
 434                 return;
 435         }
 436
 437         /*
 438          * Something removed from the tree?
 439          */
 440         if (!idx) {
 441                 diff_index_show_file(revs, "-", tree, &tree->oid, 1,
 442                                      tree->ce_mode, 0);
 443                 return;
 444         }
 445
 446         /* Show difference between old and new */
 447         show_modified(revs, tree, idx, 1, cached, match_missing);
 448 }
 449
 450 /*
 451  * The unpack_trees() interface is designed for merging, so
 452  * the different source entries are designed primarily for
 453  * the source trees, with the old index being really mainly
 454  * used for being replaced by the result.
 455  *
 456  * For diffing, the index is more important, and we only have a
 457  * single tree.
 458  *
 459  * We're supposed to advance o->pos to skip what we have already processed.
 460  *
 461  * This wrapper makes it all more readable, and takes care of all
 462  * the fairly complex unpack_trees() semantic requirements, including
 463  * the skipping, the path matching, the type conflict cases etc.
 464  */
 465 static int oneway_diff(const struct cache_entry * const *src,
 466                        struct unpack_trees_options *o)
 467 {
 468         const struct cache_entry *idx = src[0];
 469         const struct cache_entry *tree = src[1];
 470         struct rev_info *revs = o->unpack_data;
 471
 472         /*
 473          * Unpack-trees generates a DF/conflict entry if
 474          * there was a directory in the index and a tree
 475          * in the tree. From a diff standpoint, that's a
 476          * delete of the tree and a create of the file.
 477          */
 478         if (tree == o->df_conflict_entry)
 479                 tree = NULL;
 480
 481         if (ce_path_match(revs->diffopt.repo->index,
 482                           idx ? idx : tree,
 483                           &revs->prune_data, NULL)) {
 484                 do_oneway_diff(o, idx, tree);
 485                 if (diff_can_quit_early(&revs->diffopt)) {
 486                         o->exiting_early = 1;
 487                         return -1;
 488                 }
 489         }
 490
 491         return 0;
 492 }
 493
 494 static int diff_cache(struct rev_info *revs,
 495                       const struct object_id *tree_oid,
 496                       const char *tree_name,
 497                       int cached)
 498 {
 499         struct tree *tree;
 500         struct tree_desc t;
 501         struct unpack_trees_options opts;
 502
 503         tree = parse_tree_indirect(tree_oid);
 504         if (!tree)
 505                 return error("bad tree object %s",
 506                              tree_name ? tree_name : oid_to_hex(tree_oid));
 507         memset(&opts, 0, sizeof(opts));
 508         opts.head_idx = 1;
 509         opts.index_only = cached;
 510         opts.diff_index_cached = (cached &&
 511                                   !revs->diffopt.flags.find_copies_harder);
 512         opts.merge = 1;
 513         opts.fn = oneway_diff;
 514         opts.unpack_data = revs;
 515         opts.src_index = revs->diffopt.repo->index;
 516         opts.dst_index = NULL;
 517         opts.pathspec = &revs->diffopt.pathspec;
 518         opts.pathspec->recursive = 1;
 519
 520         init_tree_desc(&t, tree->buffer, tree->size);
 521         return unpack_trees(1, &t, &opts);
 522 }
 523
 524 int run_diff_index(struct rev_info *revs, int cached)
 525 {
 526         struct object_array_entry *ent;
 527
 528         if (revs->pending.nr != 1)
 529                 BUG("run_diff_index must be passed exactly one tree");
 530
 531         trace_performance_enter();
 532         ent = revs->pending.objects;
 533         if (diff_cache(revs, &ent->item->oid, ent->name, cached))
 534                 exit(128);
 535
 536         diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
 537         diffcore_fix_diff_index();
 538         diffcore_std(&revs->diffopt);
 539         diff_flush(&revs->diffopt);
 540         trace_performance_leave("diff-index");
 541         return 0;
 542 }
 543
 544 int do_diff_cache(const struct object_id *tree_oid, struct diff_options *opt)
 545 {
 546         struct rev_info revs;
 547
 548         repo_init_revisions(opt->repo, &revs, NULL);
 549         copy_pathspec(&revs.prune_data, &opt->pathspec);
 550         revs.diffopt = *opt;
 551
 552         if (diff_cache(&revs, tree_oid, NULL, 1))
 553                 exit(128);
 554         return 0;
 555 }
 556
 557 int index_differs_from(struct repository *r,
 558                        const char *def, const struct diff_flags *flags,
 559                        int ita_invisible_in_index)
 560 {
 561         struct rev_info rev;
 562         struct setup_revision_opt opt;
 563
 564         repo_init_revisions(r, &rev, NULL);
 565         memset(&opt, 0, sizeof(opt));
 566         opt.def = def;
 567         setup_revisions(0, NULL, &rev, &opt);
 568         rev.diffopt.flags.quick = 1;
 569         rev.diffopt.flags.exit_with_status = 1;
 570         if (flags)
 571                 diff_flags_or(&rev.diffopt.flags, flags);
 572         rev.diffopt.ita_invisible_in_index = ita_invisible_in_index;
 573         run_diff_index(&rev, 1);
 574         object_array_clear(&rev.pending);
 575         return (rev.diffopt.flags.has_changes != 0);
 576 }
 577
 578 static struct strbuf *idiff_prefix_cb(struct diff_options *opt, void *data)
 579 {
 580         return data;
 581 }
 582
 583 void show_interdiff(const struct object_id *oid1, const struct object_id *oid2,
 584                     int indent, struct diff_options *diffopt)
 585 {
 586         struct diff_options opts;
 587         struct strbuf prefix = STRBUF_INIT;
 588
 589         memcpy(&opts, diffopt, sizeof(opts));
 590         opts.output_format = DIFF_FORMAT_PATCH;
 591         opts.output_prefix = idiff_prefix_cb;
 592         strbuf_addchars(&prefix, ' ', indent);
 593         opts.output_prefix_data = &prefix;
 594         diff_setup_done(&opts);
 595
 596         diff_tree_oid(oid1, oid2, "", &opts);
 597         diffcore_std(&opts);
 598         diff_flush(&opts);
 599
 600         strbuf_release(&prefix);
 601 }