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         if (diff_unmerged_stage < 0)
 101                 diff_unmerged_stage = 2;
 102         entries = istate->cache_nr;
 103         for (i = 0; i < entries; i++) {
 104                 unsigned int oldmode, newmode;
 105                 struct cache_entry *ce = istate->cache[i];
 106                 int changed;
 107                 unsigned dirty_submodule = 0;
 108                 const struct object_id *old_oid, *new_oid;
 109
 110                 if (diff_can_quit_early(&revs->diffopt))
 111                         break;
 112
 113                 if (!ce_path_match(istate, ce, &revs->prune_data, NULL))
 114                         continue;
 115
 116                 if (ce_stage(ce)) {
 117                         struct combine_diff_path *dpath;
 118                         struct diff_filepair *pair;
 119                         unsigned int wt_mode = 0;
 120                         int num_compare_stages = 0;
 121                         size_t path_len;
 122                         struct stat st;
 123
 124                         path_len = ce_namelen(ce);
 125
 126                         dpath = xmalloc(combine_diff_path_size(5, path_len));
 127                         dpath->path = (char *) &(dpath->parent[5]);
 128
 129                         dpath->next = NULL;
 130                         memcpy(dpath->path, ce->name, path_len);
 131                         dpath->path[path_len] = '\0';
 132                         oidclr(&dpath->oid);
 133                         memset(&(dpath->parent[0]), 0,
 134                                sizeof(struct combine_diff_parent)*5);
 135
 136                         changed = check_removed(ce, &st);
 137                         if (!changed)
 138                                 wt_mode = ce_mode_from_stat(ce, st.st_mode);
 139                         else {
 140                                 if (changed < 0) {
 141                                         perror(ce->name);
 142                                         continue;
 143                                 }
 144                                 wt_mode = 0;
 145                         }
 146                         dpath->mode = wt_mode;
 147
 148                         while (i < entries) {
 149                                 struct cache_entry *nce = istate->cache[i];
 150                                 int stage;
 151
 152                                 if (strcmp(ce->name, nce->name))
 153                                         break;
 154
 155                                 /* Stage #2 (ours) is the first parent,
 156                                  * stage #3 (theirs) is the second.
 157                                  */
 158                                 stage = ce_stage(nce);
 159                                 if (2 <= stage) {
 160                                         int mode = nce->ce_mode;
 161                                         num_compare_stages++;
 162                                         oidcpy(&dpath->parent[stage - 2].oid,
 163                                                &nce->oid);
 164                                         dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
 165                                         dpath->parent[stage-2].status =
 166                                                 DIFF_STATUS_MODIFIED;
 167                                 }
 168
 169                                 /* diff against the proper unmerged stage */
 170                                 if (stage == diff_unmerged_stage)
 171                                         ce = nce;
 172                                 i++;
 173                         }
 174                         /*
 175                          * Compensate for loop update
 176                          */
 177                         i--;
 178
 179                         if (revs->combine_merges && num_compare_stages == 2) {
 180                                 show_combined_diff(dpath, 2, 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                                 newmode = ce_mode_from_stat(ce, st.st_mode);
 221                                 diff_addremove(&revs->diffopt, '+', newmode,
 222                                                &null_oid, 0, 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(istate, 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         trace_performance_since(start, "diff-files");
 250         return 0;
 251 }
 252
 253 /*
 254  * diff-index
 255  */
 256
 257 /* A file entry went away or appeared */
 258 static void diff_index_show_file(struct rev_info *revs,
 259                                  const char *prefix,
 260                                  const struct cache_entry *ce,
 261                                  const struct object_id *oid, int oid_valid,
 262                                  unsigned int mode,
 263                                  unsigned dirty_submodule)
 264 {
 265         diff_addremove(&revs->diffopt, prefix[0], mode,
 266                        oid, oid_valid, ce->name, dirty_submodule);
 267 }
 268
 269 static int get_stat_data(const struct cache_entry *ce,
 270                          const struct object_id **oidp,
 271                          unsigned int *modep,
 272                          int cached, int match_missing,
 273                          unsigned *dirty_submodule, struct diff_options *diffopt)
 274 {
 275         const struct object_id *oid = &ce->oid;
 276         unsigned int mode = ce->ce_mode;
 277
 278         if (!cached && !ce_uptodate(ce)) {
 279                 int changed;
 280                 struct stat st;
 281                 changed = check_removed(ce, &st);
 282                 if (changed < 0)
 283                         return -1;
 284                 else if (changed) {
 285                         if (match_missing) {
 286                                 *oidp = oid;
 287                                 *modep = mode;
 288                                 return 0;
 289                         }
 290                         return -1;
 291                 }
 292                 changed = match_stat_with_submodule(diffopt, ce, &st,
 293                                                     0, dirty_submodule);
 294                 if (changed) {
 295                         mode = ce_mode_from_stat(ce, st.st_mode);
 296                         oid = &null_oid;
 297                 }
 298         }
 299
 300         *oidp = oid;
 301         *modep = mode;
 302         return 0;
 303 }
 304
 305 static void show_new_file(struct rev_info *revs,
 306                           const struct cache_entry *new_file,
 307                           int cached, int match_missing)
 308 {
 309         const struct object_id *oid;
 310         unsigned int mode;
 311         unsigned dirty_submodule = 0;
 312
 313         /*
 314          * New file in the index: it might actually be different in
 315          * the working tree.
 316          */
 317         if (get_stat_data(new_file, &oid, &mode, cached, match_missing,
 318             &dirty_submodule, &revs->diffopt) < 0)
 319                 return;
 320
 321         diff_index_show_file(revs, "+", new_file, oid, !is_null_oid(oid), mode, dirty_submodule);
 322 }
 323
 324 static int show_modified(struct rev_info *revs,
 325                          const struct cache_entry *old_entry,
 326                          const struct cache_entry *new_entry,
 327                          int report_missing,
 328                          int cached, int match_missing)
 329 {
 330         unsigned int mode, oldmode;
 331         const struct object_id *oid;
 332         unsigned dirty_submodule = 0;
 333
 334         if (get_stat_data(new_entry, &oid, &mode, cached, match_missing,
 335                           &dirty_submodule, &revs->diffopt) < 0) {
 336                 if (report_missing)
 337                         diff_index_show_file(revs, "-", old_entry,
 338                                              &old_entry->oid, 1, old_entry->ce_mode,
 339                                              0);
 340                 return -1;
 341         }
 342
 343         if (revs->combine_merges && !cached &&
 344             (!oideq(oid, &old_entry->oid) || !oideq(&old_entry->oid, &new_entry->oid))) {
 345                 struct combine_diff_path *p;
 346                 int pathlen = ce_namelen(new_entry);
 347
 348                 p = xmalloc(combine_diff_path_size(2, pathlen));
 349                 p->path = (char *) &p->parent[2];
 350                 p->next = NULL;
 351                 memcpy(p->path, new_entry->name, pathlen);
 352                 p->path[pathlen] = 0;
 353                 p->mode = mode;
 354                 oidclr(&p->oid);
 355                 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
 356                 p->parent[0].status = DIFF_STATUS_MODIFIED;
 357                 p->parent[0].mode = new_entry->ce_mode;
 358                 oidcpy(&p->parent[0].oid, &new_entry->oid);
 359                 p->parent[1].status = DIFF_STATUS_MODIFIED;
 360                 p->parent[1].mode = old_entry->ce_mode;
 361                 oidcpy(&p->parent[1].oid, &old_entry->oid);
 362                 show_combined_diff(p, 2, revs);
 363                 free(p);
 364                 return 0;
 365         }
 366
 367         oldmode = old_entry->ce_mode;
 368         if (mode == oldmode && oideq(oid, &old_entry->oid) && !dirty_submodule &&
 369             !revs->diffopt.flags.find_copies_harder)
 370                 return 0;
 371
 372         diff_change(&revs->diffopt, oldmode, mode,
 373                     &old_entry->oid, oid, 1, !is_null_oid(oid),
 374                     old_entry->name, 0, dirty_submodule);
 375         return 0;
 376 }
 377
 378 /*
 379  * This gets a mix of an existing index and a tree, one pathname entry
 380  * at a time. The index entry may be a single stage-0 one, but it could
 381  * also be multiple unmerged entries (in which case idx_pos/idx_nr will
 382  * give you the position and number of entries in the index).
 383  */
 384 static void do_oneway_diff(struct unpack_trees_options *o,
 385                            const struct cache_entry *idx,
 386                            const struct cache_entry *tree)
 387 {
 388         struct rev_info *revs = o->unpack_data;
 389         int match_missing, cached;
 390
 391         /*
 392          * i-t-a entries do not actually exist in the index (if we're
 393          * looking at its content)
 394          */
 395         if (o->index_only &&
 396             revs->diffopt.ita_invisible_in_index &&
 397             idx && ce_intent_to_add(idx)) {
 398                 idx = NULL;
 399                 if (!tree)
 400                         return; /* nothing to diff.. */
 401         }
 402
 403         /* if the entry is not checked out, don't examine work tree */
 404         cached = o->index_only ||
 405                 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
 406
 407         match_missing = revs->match_missing;
 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(revs->diffopt.repo->index,
 471                           idx ? idx : tree,
 472                           &revs->prune_data, NULL)) {
 473                 do_oneway_diff(o, idx, tree);
 474                 if (diff_can_quit_early(&revs->diffopt)) {
 475                         o->exiting_early = 1;
 476                         return -1;
 477                 }
 478         }
 479
 480         return 0;
 481 }
 482
 483 static int diff_cache(struct rev_info *revs,
 484                       const struct object_id *tree_oid,
 485                       const char *tree_name,
 486                       int cached)
 487 {
 488         struct tree *tree;
 489         struct tree_desc t;
 490         struct unpack_trees_options opts;
 491
 492         tree = parse_tree_indirect(tree_oid);
 493         if (!tree)
 494                 return error("bad tree object %s",
 495                              tree_name ? tree_name : oid_to_hex(tree_oid));
 496         memset(&opts, 0, sizeof(opts));
 497         opts.head_idx = 1;
 498         opts.index_only = cached;
 499         opts.diff_index_cached = (cached &&
 500                                   !revs->diffopt.flags.find_copies_harder);
 501         opts.merge = 1;
 502         opts.fn = oneway_diff;
 503         opts.unpack_data = revs;
 504         opts.src_index = revs->diffopt.repo->index;
 505         opts.dst_index = NULL;
 506         opts.pathspec = &revs->diffopt.pathspec;
 507         opts.pathspec->recursive = 1;
 508
 509         init_tree_desc(&t, tree->buffer, tree->size);
 510         return unpack_trees(1, &t, &opts);
 511 }
 512
 513 int run_diff_index(struct rev_info *revs, int cached)
 514 {
 515         struct object_array_entry *ent;
 516
 517         if (revs->pending.nr != 1)
 518                 BUG("run_diff_index must be passed exactly one tree");
 519
 520         trace_performance_enter();
 521         ent = revs->pending.objects;
 522         if (diff_cache(revs, &ent->item->oid, ent->name, cached))
 523                 exit(128);
 524
 525         diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
 526         diffcore_fix_diff_index();
 527         diffcore_std(&revs->diffopt);
 528         diff_flush(&revs->diffopt);
 529         trace_performance_leave("diff-index");
 530         return 0;
 531 }
 532
 533 int do_diff_cache(const struct object_id *tree_oid, struct diff_options *opt)
 534 {
 535         struct rev_info revs;
 536
 537         repo_init_revisions(opt->repo, &revs, NULL);
 538         copy_pathspec(&revs.prune_data, &opt->pathspec);
 539         revs.diffopt = *opt;
 540
 541         if (diff_cache(&revs, tree_oid, NULL, 1))
 542                 exit(128);
 543         return 0;
 544 }
 545
 546 int index_differs_from(struct repository *r,
 547                        const char *def, const struct diff_flags *flags,
 548                        int ita_invisible_in_index)
 549 {
 550         struct rev_info rev;
 551         struct setup_revision_opt opt;
 552
 553         repo_init_revisions(r, &rev, NULL);
 554         memset(&opt, 0, sizeof(opt));
 555         opt.def = def;
 556         setup_revisions(0, NULL, &rev, &opt);
 557         rev.diffopt.flags.quick = 1;
 558         rev.diffopt.flags.exit_with_status = 1;
 559         if (flags)
 560                 diff_flags_or(&rev.diffopt.flags, flags);
 561         rev.diffopt.ita_invisible_in_index = ita_invisible_in_index;
 562         run_diff_index(&rev, 1);
 563         object_array_clear(&rev.pending);
 564         return (rev.diffopt.flags.has_changes != 0);
 565 }
 566
 567 static struct strbuf *idiff_prefix_cb(struct diff_options *opt, void *data)
 568 {
 569         return data;
 570 }
 571
 572 void show_interdiff(const struct object_id *oid1, const struct object_id *oid2,
 573                     int indent, struct diff_options *diffopt)
 574 {
 575         struct diff_options opts;
 576         struct strbuf prefix = STRBUF_INIT;
 577
 578         memcpy(&opts, diffopt, sizeof(opts));
 579         opts.output_format = DIFF_FORMAT_PATCH;
 580         opts.output_prefix = idiff_prefix_cb;
 581         strbuf_addchars(&prefix, ' ', indent);
 582         opts.output_prefix_data = &prefix;
 583         diff_setup_done(&opts);
 584
 585         diff_tree_oid(oid1, oid2, "", &opts);
 586         diffcore_std(&opts);
 587         diff_flush(&opts);
 588
 589         strbuf_release(&prefix);
 590 }