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