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
  15 /*
  16  * diff-files
  17  */
  18
  19 /*
  20  * Has the work tree entity been removed?
  21  *
  22  * Return 1 if it was removed from the work tree, 0 if an entity to be
  23  * compared with the cache entry ce still exists (the latter includes
  24  * the case where a directory that is not a submodule repository
  25  * exists for ce that is a submodule -- it is a submodule that is not
  26  * checked out).  Return negative for an error.
  27  */
  28 static int check_removed(const struct cache_entry *ce, struct stat *st)
  29 {
  30         if (lstat(ce->name, st) < 0) {
  31                 if (errno != ENOENT && errno != ENOTDIR)
  32                         return -1;
  33                 return 1;
  34         }
  35         if (has_symlink_leading_path(ce->name, ce_namelen(ce)))
  36                 return 1;
  37         if (S_ISDIR(st->st_mode)) {
  38                 unsigned char sub[20];
  39
  40                 /*
  41                  * If ce is already a gitlink, we can have a plain
  42                  * directory (i.e. the submodule is not checked out),
  43                  * or a checked out submodule.  Either case this is not
  44                  * a case where something was removed from the work tree,
  45                  * so we will return 0.
  46                  *
  47                  * Otherwise, if the directory is not a submodule
  48                  * repository, that means ce which was a blob turned into
  49                  * a directory --- the blob was removed!
  50                  */
  51                 if (!S_ISGITLINK(ce->ce_mode) &&
  52                     resolve_gitlink_ref(ce->name, "HEAD", sub))
  53                         return 1;
  54         }
  55         return 0;
  56 }
  57
  58 /*
  59  * Has a file changed or has a submodule new commits or a dirty work tree?
  60  *
  61  * Return 1 when changes are detected, 0 otherwise. If the DIRTY_SUBMODULES
  62  * option is set, the caller does not only want to know if a submodule is
  63  * modified at all but wants to know all the conditions that are met (new
  64  * commits, untracked content and/or modified content).
  65  */
  66 static int match_stat_with_submodule(struct diff_options *diffopt,
  67                                       struct cache_entry *ce, struct stat *st,
  68                                       unsigned ce_option, unsigned *dirty_submodule)
  69 {
  70         int changed = ce_match_stat(ce, st, ce_option);
  71         if (S_ISGITLINK(ce->ce_mode)) {
  72                 unsigned orig_flags = diffopt->flags;
  73                 if (!DIFF_OPT_TST(diffopt, OVERRIDE_SUBMODULE_CONFIG))
  74                         set_diffopt_flags_from_submodule_config(diffopt, ce->name);
  75                 if (DIFF_OPT_TST(diffopt, IGNORE_SUBMODULES))
  76                         changed = 0;
  77                 else if (!DIFF_OPT_TST(diffopt, IGNORE_DIRTY_SUBMODULES)
  78                     && (!changed || DIFF_OPT_TST(diffopt, DIRTY_SUBMODULES)))
  79                         *dirty_submodule = is_submodule_modified(ce->name, DIFF_OPT_TST(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES));
  80                 diffopt->flags = orig_flags;
  81         }
  82         return changed;
  83 }
  84
  85 int run_diff_files(struct rev_info *revs, unsigned int option)
  86 {
  87         int entries, i;
  88         int diff_unmerged_stage = revs->max_count;
  89         int silent_on_removed = option & DIFF_SILENT_ON_REMOVED;
  90         unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
  91                               ? CE_MATCH_RACY_IS_DIRTY : 0);
  92
  93         diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
  94
  95         if (diff_unmerged_stage < 0)
  96                 diff_unmerged_stage = 2;
  97         entries = active_nr;
  98         for (i = 0; i < entries; i++) {
  99                 struct stat st;
 100                 unsigned int oldmode, newmode;
 101                 struct cache_entry *ce = active_cache[i];
 102                 int changed;
 103                 unsigned dirty_submodule = 0;
 104
 105                 if (DIFF_OPT_TST(&revs->diffopt, QUICK) &&
 106                         DIFF_OPT_TST(&revs->diffopt, HAS_CHANGES))
 107                         break;
 108
 109                 if (!ce_path_match(ce, revs->prune_data))
 110                         continue;
 111
 112                 if (ce_stage(ce)) {
 113                         struct combine_diff_path *dpath;
 114                         int num_compare_stages = 0;
 115                         size_t path_len;
 116
 117                         path_len = ce_namelen(ce);
 118
 119                         dpath = xmalloc(combine_diff_path_size(5, path_len));
 120                         dpath->path = (char *) &(dpath->parent[5]);
 121
 122                         dpath->next = NULL;
 123                         dpath->len = path_len;
 124                         memcpy(dpath->path, ce->name, path_len);
 125                         dpath->path[path_len] = '\0';
 126                         hashclr(dpath->sha1);
 127                         memset(&(dpath->parent[0]), 0,
 128                                sizeof(struct combine_diff_parent)*5);
 129
 130                         changed = check_removed(ce, &st);
 131                         if (!changed)
 132                                 dpath->mode = ce_mode_from_stat(ce, st.st_mode);
 133                         else {
 134                                 if (changed < 0) {
 135                                         perror(ce->name);
 136                                         continue;
 137                                 }
 138                                 if (silent_on_removed)
 139                                         continue;
 140                         }
 141
 142                         while (i < entries) {
 143                                 struct cache_entry *nce = active_cache[i];
 144                                 int stage;
 145
 146                                 if (strcmp(ce->name, nce->name))
 147                                         break;
 148
 149                                 /* Stage #2 (ours) is the first parent,
 150                                  * stage #3 (theirs) is the second.
 151                                  */
 152                                 stage = ce_stage(nce);
 153                                 if (2 <= stage) {
 154                                         int mode = nce->ce_mode;
 155                                         num_compare_stages++;
 156                                         hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
 157                                         dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
 158                                         dpath->parent[stage-2].status =
 159                                                 DIFF_STATUS_MODIFIED;
 160                                 }
 161
 162                                 /* diff against the proper unmerged stage */
 163                                 if (stage == diff_unmerged_stage)
 164                                         ce = nce;
 165                                 i++;
 166                         }
 167                         /*
 168                          * Compensate for loop update
 169                          */
 170                         i--;
 171
 172                         if (revs->combine_merges && num_compare_stages == 2) {
 173                                 show_combined_diff(dpath, 2,
 174                                                    revs->dense_combined_merges,
 175                                                    revs);
 176                                 free(dpath);
 177                                 continue;
 178                         }
 179                         free(dpath);
 180                         dpath = NULL;
 181
 182                         /*
 183                          * Show the diff for the 'ce' if we found the one
 184                          * from the desired stage.
 185                          */
 186                         diff_unmerge(&revs->diffopt, ce->name, 0, null_sha1);
 187                         if (ce_stage(ce) != diff_unmerged_stage)
 188                                 continue;
 189                 }
 190
 191                 if (ce_uptodate(ce) || ce_skip_worktree(ce))
 192                         continue;
 193
 194                 /* If CE_VALID is set, don't look at workdir for file removal */
 195                 changed = (ce->ce_flags & CE_VALID) ? 0 : check_removed(ce, &st);
 196                 if (changed) {
 197                         if (changed < 0) {
 198                                 perror(ce->name);
 199                                 continue;
 200                         }
 201                         if (silent_on_removed)
 202                                 continue;
 203                         diff_addremove(&revs->diffopt, '-', ce->ce_mode,
 204                                        ce->sha1, ce->name, 0);
 205                         continue;
 206                 }
 207                 changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
 208                                                     ce_option, &dirty_submodule);
 209                 if (!changed && !dirty_submodule) {
 210                         ce_mark_uptodate(ce);
 211                         if (!DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
 212                                 continue;
 213                 }
 214                 oldmode = ce->ce_mode;
 215                 newmode = ce_mode_from_stat(ce, st.st_mode);
 216                 diff_change(&revs->diffopt, oldmode, newmode,
 217                             ce->sha1, (changed ? null_sha1 : ce->sha1),
 218                             ce->name, 0, dirty_submodule);
 219
 220         }
 221         diffcore_std(&revs->diffopt);
 222         diff_flush(&revs->diffopt);
 223         return 0;
 224 }
 225
 226 /*
 227  * diff-index
 228  */
 229
 230 /* A file entry went away or appeared */
 231 static void diff_index_show_file(struct rev_info *revs,
 232                                  const char *prefix,
 233                                  struct cache_entry *ce,
 234                                  const unsigned char *sha1, unsigned int mode,
 235                                  unsigned dirty_submodule)
 236 {
 237         diff_addremove(&revs->diffopt, prefix[0], mode,
 238                        sha1, ce->name, dirty_submodule);
 239 }
 240
 241 static int get_stat_data(struct cache_entry *ce,
 242                          const unsigned char **sha1p,
 243                          unsigned int *modep,
 244                          int cached, int match_missing,
 245                          unsigned *dirty_submodule, struct diff_options *diffopt)
 246 {
 247         const unsigned char *sha1 = ce->sha1;
 248         unsigned int mode = ce->ce_mode;
 249
 250         if (!cached && !ce_uptodate(ce)) {
 251                 int changed;
 252                 struct stat st;
 253                 changed = check_removed(ce, &st);
 254                 if (changed < 0)
 255                         return -1;
 256                 else if (changed) {
 257                         if (match_missing) {
 258                                 *sha1p = sha1;
 259                                 *modep = mode;
 260                                 return 0;
 261                         }
 262                         return -1;
 263                 }
 264                 changed = match_stat_with_submodule(diffopt, ce, &st,
 265                                                     0, dirty_submodule);
 266                 if (changed) {
 267                         mode = ce_mode_from_stat(ce, st.st_mode);
 268                         sha1 = null_sha1;
 269                 }
 270         }
 271
 272         *sha1p = sha1;
 273         *modep = mode;
 274         return 0;
 275 }
 276
 277 static void show_new_file(struct rev_info *revs,
 278                           struct cache_entry *new,
 279                           int cached, int match_missing)
 280 {
 281         const unsigned char *sha1;
 282         unsigned int mode;
 283         unsigned dirty_submodule = 0;
 284
 285         /*
 286          * New file in the index: it might actually be different in
 287          * the working copy.
 288          */
 289         if (get_stat_data(new, &sha1, &mode, cached, match_missing,
 290             &dirty_submodule, &revs->diffopt) < 0)
 291                 return;
 292
 293         diff_index_show_file(revs, "+", new, sha1, mode, dirty_submodule);
 294 }
 295
 296 static int show_modified(struct rev_info *revs,
 297                          struct cache_entry *old,
 298                          struct cache_entry *new,
 299                          int report_missing,
 300                          int cached, int match_missing)
 301 {
 302         unsigned int mode, oldmode;
 303         const unsigned char *sha1;
 304         unsigned dirty_submodule = 0;
 305
 306         if (get_stat_data(new, &sha1, &mode, cached, match_missing,
 307                           &dirty_submodule, &revs->diffopt) < 0) {
 308                 if (report_missing)
 309                         diff_index_show_file(revs, "-", old,
 310                                              old->sha1, old->ce_mode, 0);
 311                 return -1;
 312         }
 313
 314         if (revs->combine_merges && !cached &&
 315             (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
 316                 struct combine_diff_path *p;
 317                 int pathlen = ce_namelen(new);
 318
 319                 p = xmalloc(combine_diff_path_size(2, pathlen));
 320                 p->path = (char *) &p->parent[2];
 321                 p->next = NULL;
 322                 p->len = pathlen;
 323                 memcpy(p->path, new->name, pathlen);
 324                 p->path[pathlen] = 0;
 325                 p->mode = mode;
 326                 hashclr(p->sha1);
 327                 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
 328                 p->parent[0].status = DIFF_STATUS_MODIFIED;
 329                 p->parent[0].mode = new->ce_mode;
 330                 hashcpy(p->parent[0].sha1, new->sha1);
 331                 p->parent[1].status = DIFF_STATUS_MODIFIED;
 332                 p->parent[1].mode = old->ce_mode;
 333                 hashcpy(p->parent[1].sha1, old->sha1);
 334                 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
 335                 free(p);
 336                 return 0;
 337         }
 338
 339         oldmode = old->ce_mode;
 340         if (mode == oldmode && !hashcmp(sha1, old->sha1) && !dirty_submodule &&
 341             !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
 342                 return 0;
 343
 344         diff_change(&revs->diffopt, oldmode, mode,
 345                     old->sha1, sha1, old->name, 0, dirty_submodule);
 346         return 0;
 347 }
 348
 349 /*
 350  * This gets a mix of an existing index and a tree, one pathname entry
 351  * at a time. The index entry may be a single stage-0 one, but it could
 352  * also be multiple unmerged entries (in which case idx_pos/idx_nr will
 353  * give you the position and number of entries in the index).
 354  */
 355 static void do_oneway_diff(struct unpack_trees_options *o,
 356         struct cache_entry *idx,
 357         struct cache_entry *tree)
 358 {
 359         struct rev_info *revs = o->unpack_data;
 360         int match_missing, cached;
 361
 362         /* if the entry is not checked out, don't examine work tree */
 363         cached = o->index_only ||
 364                 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
 365         /*
 366          * Backward compatibility wart - "diff-index -m" does
 367          * not mean "do not ignore merges", but "match_missing".
 368          *
 369          * But with the revision flag parsing, that's found in
 370          * "!revs->ignore_merges".
 371          */
 372         match_missing = !revs->ignore_merges;
 373
 374         if (cached && idx && ce_stage(idx)) {
 375                 diff_unmerge(&revs->diffopt, idx->name, idx->ce_mode,
 376                              idx->sha1);
 377                 return;
 378         }
 379
 380         /*
 381          * Something added to the tree?
 382          */
 383         if (!tree) {
 384                 show_new_file(revs, idx, cached, match_missing);
 385                 return;
 386         }
 387
 388         /*
 389          * Something removed from the tree?
 390          */
 391         if (!idx) {
 392                 diff_index_show_file(revs, "-", tree, tree->sha1, tree->ce_mode, 0);
 393                 return;
 394         }
 395
 396         /* Show difference between old and new */
 397         show_modified(revs, tree, idx, 1, cached, match_missing);
 398 }
 399
 400 /*
 401  * The unpack_trees() interface is designed for merging, so
 402  * the different source entries are designed primarily for
 403  * the source trees, with the old index being really mainly
 404  * used for being replaced by the result.
 405  *
 406  * For diffing, the index is more important, and we only have a
 407  * single tree.
 408  *
 409  * We're supposed to advance o->pos to skip what we have already processed.
 410  *
 411  * This wrapper makes it all more readable, and takes care of all
 412  * the fairly complex unpack_trees() semantic requirements, including
 413  * the skipping, the path matching, the type conflict cases etc.
 414  */
 415 static int oneway_diff(struct cache_entry **src, struct unpack_trees_options *o)
 416 {
 417         struct cache_entry *idx = src[0];
 418         struct cache_entry *tree = src[1];
 419         struct rev_info *revs = o->unpack_data;
 420
 421         /*
 422          * Unpack-trees generates a DF/conflict entry if
 423          * there was a directory in the index and a tree
 424          * in the tree. From a diff standpoint, that's a
 425          * delete of the tree and a create of the file.
 426          */
 427         if (tree == o->df_conflict_entry)
 428                 tree = NULL;
 429
 430         if (ce_path_match(idx ? idx : tree, revs->prune_data))
 431                 do_oneway_diff(o, idx, tree);
 432
 433         return 0;
 434 }
 435
 436 int run_diff_index(struct rev_info *revs, int cached)
 437 {
 438         struct object *ent;
 439         struct tree *tree;
 440         const char *tree_name;
 441         struct unpack_trees_options opts;
 442         struct tree_desc t;
 443
 444         ent = revs->pending.objects[0].item;
 445         tree_name = revs->pending.objects[0].name;
 446         tree = parse_tree_indirect(ent->sha1);
 447         if (!tree)
 448                 return error("bad tree object %s", tree_name);
 449
 450         memset(&opts, 0, sizeof(opts));
 451         opts.head_idx = 1;
 452         opts.index_only = cached;
 453         opts.diff_index_cached = (cached &&
 454                                   !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER));
 455         opts.merge = 1;
 456         opts.fn = oneway_diff;
 457         opts.unpack_data = revs;
 458         opts.src_index = &the_index;
 459         opts.dst_index = NULL;
 460
 461         init_tree_desc(&t, tree->buffer, tree->size);
 462         if (unpack_trees(1, &t, &opts))
 463                 exit(128);
 464
 465         diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
 466         diffcore_fix_diff_index(&revs->diffopt);
 467         diffcore_std(&revs->diffopt);
 468         diff_flush(&revs->diffopt);
 469         return 0;
 470 }
 471
 472 int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
 473 {
 474         struct tree *tree;
 475         struct rev_info revs;
 476         int i;
 477         struct cache_entry **dst;
 478         struct cache_entry *last = NULL;
 479         struct unpack_trees_options opts;
 480         struct tree_desc t;
 481
 482         /*
 483          * This is used by git-blame to run diff-cache internally;
 484          * it potentially needs to repeatedly run this, so we will
 485          * start by removing the higher order entries the last round
 486          * left behind.
 487          */
 488         dst = active_cache;
 489         for (i = 0; i < active_nr; i++) {
 490                 struct cache_entry *ce = active_cache[i];
 491                 if (ce_stage(ce)) {
 492                         if (last && !strcmp(ce->name, last->name))
 493                                 continue;
 494                         cache_tree_invalidate_path(active_cache_tree,
 495                                                    ce->name);
 496                         last = ce;
 497                         ce->ce_flags |= CE_REMOVE;
 498                 }
 499                 *dst++ = ce;
 500         }
 501         active_nr = dst - active_cache;
 502
 503         init_revisions(&revs, NULL);
 504         revs.prune_data = opt->paths;
 505         tree = parse_tree_indirect(tree_sha1);
 506         if (!tree)
 507                 die("bad tree object %s", sha1_to_hex(tree_sha1));
 508
 509         memset(&opts, 0, sizeof(opts));
 510         opts.head_idx = 1;
 511         opts.index_only = 1;
 512         opts.diff_index_cached = !DIFF_OPT_TST(opt, FIND_COPIES_HARDER);
 513         opts.merge = 1;
 514         opts.fn = oneway_diff;
 515         opts.unpack_data = &revs;
 516         opts.src_index = &the_index;
 517         opts.dst_index = &the_index;
 518
 519         init_tree_desc(&t, tree->buffer, tree->size);
 520         if (unpack_trees(1, &t, &opts))
 521                 exit(128);
 522         return 0;
 523 }
 524
 525 int index_differs_from(const char *def, int diff_flags)
 526 {
 527         struct rev_info rev;
 528         struct setup_revision_opt opt;
 529
 530         init_revisions(&rev, NULL);
 531         memset(&opt, 0, sizeof(opt));
 532         opt.def = def;
 533         setup_revisions(0, NULL, &rev, &opt);
 534         DIFF_OPT_SET(&rev.diffopt, QUICK);
 535         DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
 536         rev.diffopt.flags |= diff_flags;
 537         run_diff_index(&rev, 1);
 538         if (rev.pending.alloc)
 539                 free(rev.pending.objects);
 540         return (DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES) != 0);
 541 }