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                     !revs->diffopt.filter &&
 107                     DIFF_OPT_TST(&revs->diffopt, HAS_CHANGES))
 108                         break;
 109
 110                 if (!ce_path_match(ce, revs->prune_data))
 111                         continue;
 112
 113                 if (ce_stage(ce)) {
 114                         struct combine_diff_path *dpath;
 115                         int num_compare_stages = 0;
 116                         size_t path_len;
 117
 118                         path_len = ce_namelen(ce);
 119
 120                         dpath = xmalloc(combine_diff_path_size(5, path_len));
 121                         dpath->path = (char *) &(dpath->parent[5]);
 122
 123                         dpath->next = NULL;
 124                         dpath->len = path_len;
 125                         memcpy(dpath->path, ce->name, path_len);
 126                         dpath->path[path_len] = '\0';
 127                         hashclr(dpath->sha1);
 128                         memset(&(dpath->parent[0]), 0,
 129                                sizeof(struct combine_diff_parent)*5);
 130
 131                         changed = check_removed(ce, &st);
 132                         if (!changed)
 133                                 dpath->mode = ce_mode_from_stat(ce, st.st_mode);
 134                         else {
 135                                 if (changed < 0) {
 136                                         perror(ce->name);
 137                                         continue;
 138                                 }
 139                                 if (silent_on_removed)
 140                                         continue;
 141                         }
 142
 143                         while (i < entries) {
 144                                 struct cache_entry *nce = active_cache[i];
 145                                 int stage;
 146
 147                                 if (strcmp(ce->name, nce->name))
 148                                         break;
 149
 150                                 /* Stage #2 (ours) is the first parent,
 151                                  * stage #3 (theirs) is the second.
 152                                  */
 153                                 stage = ce_stage(nce);
 154                                 if (2 <= stage) {
 155                                         int mode = nce->ce_mode;
 156                                         num_compare_stages++;
 157                                         hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
 158                                         dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
 159                                         dpath->parent[stage-2].status =
 160                                                 DIFF_STATUS_MODIFIED;
 161                                 }
 162
 163                                 /* diff against the proper unmerged stage */
 164                                 if (stage == diff_unmerged_stage)
 165                                         ce = nce;
 166                                 i++;
 167                         }
 168                         /*
 169                          * Compensate for loop update
 170                          */
 171                         i--;
 172
 173                         if (revs->combine_merges && num_compare_stages == 2) {
 174                                 show_combined_diff(dpath, 2,
 175                                                    revs->dense_combined_merges,
 176                                                    revs);
 177                                 free(dpath);
 178                                 continue;
 179                         }
 180                         free(dpath);
 181                         dpath = NULL;
 182
 183                         /*
 184                          * Show the diff for the 'ce' if we found the one
 185                          * from the desired stage.
 186                          */
 187                         diff_unmerge(&revs->diffopt, ce->name, 0, null_sha1);
 188                         if (ce_stage(ce) != diff_unmerged_stage)
 189                                 continue;
 190                 }
 191
 192                 if (ce_uptodate(ce) || ce_skip_worktree(ce))
 193                         continue;
 194
 195                 /* If CE_VALID is set, don't look at workdir for file removal */
 196                 changed = (ce->ce_flags & CE_VALID) ? 0 : check_removed(ce, &st);
 197                 if (changed) {
 198                         if (changed < 0) {
 199                                 perror(ce->name);
 200                                 continue;
 201                         }
 202                         if (silent_on_removed)
 203                                 continue;
 204                         diff_addremove(&revs->diffopt, '-', ce->ce_mode,
 205                                        ce->sha1, ce->name, 0);
 206                         continue;
 207                 }
 208                 changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
 209                                                     ce_option, &dirty_submodule);
 210                 if (!changed && !dirty_submodule) {
 211                         ce_mark_uptodate(ce);
 212                         if (!DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
 213                                 continue;
 214                 }
 215                 oldmode = ce->ce_mode;
 216                 newmode = ce_mode_from_stat(ce, st.st_mode);
 217                 diff_change(&revs->diffopt, oldmode, newmode,
 218                             ce->sha1, (changed ? null_sha1 : ce->sha1),
 219                             ce->name, 0, dirty_submodule);
 220
 221         }
 222         diffcore_std(&revs->diffopt);
 223         diff_flush(&revs->diffopt);
 224         return 0;
 225 }
 226
 227 /*
 228  * diff-index
 229  */
 230
 231 /* A file entry went away or appeared */
 232 static void diff_index_show_file(struct rev_info *revs,
 233                                  const char *prefix,
 234                                  struct cache_entry *ce,
 235                                  const unsigned char *sha1, unsigned int mode,
 236                                  unsigned dirty_submodule)
 237 {
 238         diff_addremove(&revs->diffopt, prefix[0], mode,
 239                        sha1, ce->name, dirty_submodule);
 240 }
 241
 242 static int get_stat_data(struct cache_entry *ce,
 243                          const unsigned char **sha1p,
 244                          unsigned int *modep,
 245                          int cached, int match_missing,
 246                          unsigned *dirty_submodule, struct diff_options *diffopt)
 247 {
 248         const unsigned char *sha1 = ce->sha1;
 249         unsigned int mode = ce->ce_mode;
 250
 251         if (!cached && !ce_uptodate(ce)) {
 252                 int changed;
 253                 struct stat st;
 254                 changed = check_removed(ce, &st);
 255                 if (changed < 0)
 256                         return -1;
 257                 else if (changed) {
 258                         if (match_missing) {
 259                                 *sha1p = sha1;
 260                                 *modep = mode;
 261                                 return 0;
 262                         }
 263                         return -1;
 264                 }
 265                 changed = match_stat_with_submodule(diffopt, ce, &st,
 266                                                     0, dirty_submodule);
 267                 if (changed) {
 268                         mode = ce_mode_from_stat(ce, st.st_mode);
 269                         sha1 = null_sha1;
 270                 }
 271         }
 272
 273         *sha1p = sha1;
 274         *modep = mode;
 275         return 0;
 276 }
 277
 278 static void show_new_file(struct rev_info *revs,
 279                           struct cache_entry *new,
 280                           int cached, int match_missing)
 281 {
 282         const unsigned char *sha1;
 283         unsigned int mode;
 284         unsigned dirty_submodule = 0;
 285
 286         /*
 287          * New file in the index: it might actually be different in
 288          * the working copy.
 289          */
 290         if (get_stat_data(new, &sha1, &mode, cached, match_missing,
 291             &dirty_submodule, &revs->diffopt) < 0)
 292                 return;
 293
 294         diff_index_show_file(revs, "+", new, sha1, mode, dirty_submodule);
 295 }
 296
 297 static int show_modified(struct rev_info *revs,
 298                          struct cache_entry *old,
 299                          struct cache_entry *new,
 300                          int report_missing,
 301                          int cached, int match_missing)
 302 {
 303         unsigned int mode, oldmode;
 304         const unsigned char *sha1;
 305         unsigned dirty_submodule = 0;
 306
 307         if (get_stat_data(new, &sha1, &mode, cached, match_missing,
 308                           &dirty_submodule, &revs->diffopt) < 0) {
 309                 if (report_missing)
 310                         diff_index_show_file(revs, "-", old,
 311                                              old->sha1, old->ce_mode, 0);
 312                 return -1;
 313         }
 314
 315         if (revs->combine_merges && !cached &&
 316             (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
 317                 struct combine_diff_path *p;
 318                 int pathlen = ce_namelen(new);
 319
 320                 p = xmalloc(combine_diff_path_size(2, pathlen));
 321                 p->path = (char *) &p->parent[2];
 322                 p->next = NULL;
 323                 p->len = pathlen;
 324                 memcpy(p->path, new->name, pathlen);
 325                 p->path[pathlen] = 0;
 326                 p->mode = mode;
 327                 hashclr(p->sha1);
 328                 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
 329                 p->parent[0].status = DIFF_STATUS_MODIFIED;
 330                 p->parent[0].mode = new->ce_mode;
 331                 hashcpy(p->parent[0].sha1, new->sha1);
 332                 p->parent[1].status = DIFF_STATUS_MODIFIED;
 333                 p->parent[1].mode = old->ce_mode;
 334                 hashcpy(p->parent[1].sha1, old->sha1);
 335                 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
 336                 free(p);
 337                 return 0;
 338         }
 339
 340         oldmode = old->ce_mode;
 341         if (mode == oldmode && !hashcmp(sha1, old->sha1) && !dirty_submodule &&
 342             !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
 343                 return 0;
 344
 345         diff_change(&revs->diffopt, oldmode, mode,
 346                     old->sha1, sha1, old->name, 0, dirty_submodule);
 347         return 0;
 348 }
 349
 350 /*
 351  * This gets a mix of an existing index and a tree, one pathname entry
 352  * at a time. The index entry may be a single stage-0 one, but it could
 353  * also be multiple unmerged entries (in which case idx_pos/idx_nr will
 354  * give you the position and number of entries in the index).
 355  */
 356 static void do_oneway_diff(struct unpack_trees_options *o,
 357         struct cache_entry *idx,
 358         struct cache_entry *tree)
 359 {
 360         struct rev_info *revs = o->unpack_data;
 361         int match_missing, cached;
 362
 363         /* if the entry is not checked out, don't examine work tree */
 364         cached = o->index_only ||
 365                 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
 366         /*
 367          * Backward compatibility wart - "diff-index -m" does
 368          * not mean "do not ignore merges", but "match_missing".
 369          *
 370          * But with the revision flag parsing, that's found in
 371          * "!revs->ignore_merges".
 372          */
 373         match_missing = !revs->ignore_merges;
 374
 375         if (cached && idx && ce_stage(idx)) {
 376                 diff_unmerge(&revs->diffopt, idx->name, idx->ce_mode,
 377                              idx->sha1);
 378                 return;
 379         }
 380
 381         /*
 382          * Something added to the tree?
 383          */
 384         if (!tree) {
 385                 show_new_file(revs, idx, cached, match_missing);
 386                 return;
 387         }
 388
 389         /*
 390          * Something removed from the tree?
 391          */
 392         if (!idx) {
 393                 diff_index_show_file(revs, "-", tree, tree->sha1, tree->ce_mode, 0);
 394                 return;
 395         }
 396
 397         /* Show difference between old and new */
 398         show_modified(revs, tree, idx, 1, cached, match_missing);
 399 }
 400
 401 /*
 402  * The unpack_trees() interface is designed for merging, so
 403  * the different source entries are designed primarily for
 404  * the source trees, with the old index being really mainly
 405  * used for being replaced by the result.
 406  *
 407  * For diffing, the index is more important, and we only have a
 408  * single tree.
 409  *
 410  * We're supposed to advance o->pos to skip what we have already processed.
 411  *
 412  * This wrapper makes it all more readable, and takes care of all
 413  * the fairly complex unpack_trees() semantic requirements, including
 414  * the skipping, the path matching, the type conflict cases etc.
 415  */
 416 static int oneway_diff(struct cache_entry **src, struct unpack_trees_options *o)
 417 {
 418         struct cache_entry *idx = src[0];
 419         struct cache_entry *tree = src[1];
 420         struct rev_info *revs = o->unpack_data;
 421
 422         /*
 423          * Unpack-trees generates a DF/conflict entry if
 424          * there was a directory in the index and a tree
 425          * in the tree. From a diff standpoint, that's a
 426          * delete of the tree and a create of the file.
 427          */
 428         if (tree == o->df_conflict_entry)
 429                 tree = NULL;
 430
 431         if (ce_path_match(idx ? idx : tree, revs->prune_data))
 432                 do_oneway_diff(o, idx, tree);
 433
 434         return 0;
 435 }
 436
 437 int run_diff_index(struct rev_info *revs, int cached)
 438 {
 439         struct object *ent;
 440         struct tree *tree;
 441         const char *tree_name;
 442         struct unpack_trees_options opts;
 443         struct tree_desc t;
 444
 445         ent = revs->pending.objects[0].item;
 446         tree_name = revs->pending.objects[0].name;
 447         tree = parse_tree_indirect(ent->sha1);
 448         if (!tree)
 449                 return error("bad tree object %s", tree_name);
 450
 451         memset(&opts, 0, sizeof(opts));
 452         opts.head_idx = 1;
 453         opts.index_only = cached;
 454         opts.diff_index_cached = (cached &&
 455                                   !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER));
 456         opts.merge = 1;
 457         opts.fn = oneway_diff;
 458         opts.unpack_data = revs;
 459         opts.src_index = &the_index;
 460         opts.dst_index = NULL;
 461
 462         init_tree_desc(&t, tree->buffer, tree->size);
 463         if (unpack_trees(1, &t, &opts))
 464                 exit(128);
 465
 466         diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
 467         diffcore_fix_diff_index(&revs->diffopt);
 468         diffcore_std(&revs->diffopt);
 469         diff_flush(&revs->diffopt);
 470         return 0;
 471 }
 472
 473 int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
 474 {
 475         struct tree *tree;
 476         struct rev_info revs;
 477         int i;
 478         struct cache_entry **dst;
 479         struct cache_entry *last = NULL;
 480         struct unpack_trees_options opts;
 481         struct tree_desc t;
 482
 483         /*
 484          * This is used by git-blame to run diff-cache internally;
 485          * it potentially needs to repeatedly run this, so we will
 486          * start by removing the higher order entries the last round
 487          * left behind.
 488          */
 489         dst = active_cache;
 490         for (i = 0; i < active_nr; i++) {
 491                 struct cache_entry *ce = active_cache[i];
 492                 if (ce_stage(ce)) {
 493                         if (last && !strcmp(ce->name, last->name))
 494                                 continue;
 495                         cache_tree_invalidate_path(active_cache_tree,
 496                                                    ce->name);
 497                         last = ce;
 498                         ce->ce_flags |= CE_REMOVE;
 499                 }
 500                 *dst++ = ce;
 501         }
 502         active_nr = dst - active_cache;
 503
 504         init_revisions(&revs, NULL);
 505         revs.prune_data = opt->paths;
 506         tree = parse_tree_indirect(tree_sha1);
 507         if (!tree)
 508                 die("bad tree object %s", sha1_to_hex(tree_sha1));
 509
 510         memset(&opts, 0, sizeof(opts));
 511         opts.head_idx = 1;
 512         opts.index_only = 1;
 513         opts.diff_index_cached = !DIFF_OPT_TST(opt, FIND_COPIES_HARDER);
 514         opts.merge = 1;
 515         opts.fn = oneway_diff;
 516         opts.unpack_data = &revs;
 517         opts.src_index = &the_index;
 518         opts.dst_index = &the_index;
 519
 520         init_tree_desc(&t, tree->buffer, tree->size);
 521         if (unpack_trees(1, &t, &opts))
 522                 exit(128);
 523         return 0;
 524 }
 525
 526 int index_differs_from(const char *def, int diff_flags)
 527 {
 528         struct rev_info rev;
 529         struct setup_revision_opt opt;
 530
 531         init_revisions(&rev, NULL);
 532         memset(&opt, 0, sizeof(opt));
 533         opt.def = def;
 534         setup_revisions(0, NULL, &rev, &opt);
 535         DIFF_OPT_SET(&rev.diffopt, QUICK);
 536         DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
 537         rev.diffopt.flags |= diff_flags;
 538         run_diff_index(&rev, 1);
 539         if (rev.pending.alloc)
 540                 free(rev.pending.objects);
 541         return (DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES) != 0);
 542 }