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
  16 /*
  17  * diff-files
  18  */
  19
  20 /*
  21  * Has the work tree entity been removed?
  22  *
  23  * Return 1 if it was removed from the work tree, 0 if an entity to be
  24  * compared with the cache entry ce still exists (the latter includes
  25  * the case where a directory that is not a submodule repository
  26  * exists for ce that is a submodule -- it is a submodule that is not
  27  * checked out).  Return negative for an error.
  28  */
  29 static int check_removed(const struct cache_entry *ce, struct stat *st)
  30 {
  31         if (lstat(ce->name, st) < 0) {
  32                 if (errno != ENOENT && errno != ENOTDIR)
  33                         return -1;
  34                 return 1;
  35         }
  36         if (has_symlink_leading_path(ce->name, ce_namelen(ce)))
  37                 return 1;
  38         if (S_ISDIR(st->st_mode)) {
  39                 unsigned char sub[20];
  40
  41                 /*
  42                  * If ce is already a gitlink, we can have a plain
  43                  * directory (i.e. the submodule is not checked out),
  44                  * or a checked out submodule.  Either case this is not
  45                  * a case where something was removed from the work tree,
  46                  * so we will return 0.
  47                  *
  48                  * Otherwise, if the directory is not a submodule
  49                  * repository, that means ce which was a blob turned into
  50                  * a directory --- the blob was removed!
  51                  */
  52                 if (!S_ISGITLINK(ce->ce_mode) &&
  53                     resolve_gitlink_ref(ce->name, "HEAD", sub))
  54                         return 1;
  55         }
  56         return 0;
  57 }
  58
  59 /*
  60  * Has a file changed or has a submodule new commits or a dirty work tree?
  61  *
  62  * Return 1 when changes are detected, 0 otherwise. If the DIRTY_SUBMODULES
  63  * option is set, the caller does not only want to know if a submodule is
  64  * modified at all but wants to know all the conditions that are met (new
  65  * commits, untracked content and/or modified content).
  66  */
  67 static int match_stat_with_submodule(struct diff_options *diffopt,
  68                                      const struct cache_entry *ce,
  69                                      struct stat *st, unsigned ce_option,
  70                                      unsigned *dirty_submodule)
  71 {
  72         int changed = ce_match_stat(ce, st, ce_option);
  73         if (S_ISGITLINK(ce->ce_mode)) {
  74                 unsigned orig_flags = diffopt->flags;
  75                 if (!DIFF_OPT_TST(diffopt, OVERRIDE_SUBMODULE_CONFIG))
  76                         set_diffopt_flags_from_submodule_config(diffopt, ce->name);
  77                 if (DIFF_OPT_TST(diffopt, IGNORE_SUBMODULES))
  78                         changed = 0;
  79                 else if (!DIFF_OPT_TST(diffopt, IGNORE_DIRTY_SUBMODULES)
  80                     && (!changed || DIFF_OPT_TST(diffopt, DIRTY_SUBMODULES)))
  81                         *dirty_submodule = is_submodule_modified(ce->name, DIFF_OPT_TST(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES));
  82                 diffopt->flags = orig_flags;
  83         }
  84         return changed;
  85 }
  86
  87 int run_diff_files(struct rev_info *revs, unsigned int option)
  88 {
  89         int entries, i;
  90         int diff_unmerged_stage = revs->max_count;
  91         unsigned ce_option = ((option & DIFF_RACY_IS_MODIFIED)
  92                               ? CE_MATCH_RACY_IS_DIRTY : 0);
  93
  94         diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
  95
  96         if (diff_unmerged_stage < 0)
  97                 diff_unmerged_stage = 2;
  98         entries = active_nr;
  99         for (i = 0; i < entries; i++) {
 100                 struct stat st;
 101                 unsigned int oldmode, newmode;
 102                 struct cache_entry *ce = active_cache[i];
 103                 int changed;
 104                 unsigned dirty_submodule = 0;
 105
 106                 if (diff_can_quit_early(&revs->diffopt))
 107                         break;
 108
 109                 if (!ce_path_match(ce, &revs->prune_data, NULL))
 110                         continue;
 111
 112                 if (ce_stage(ce)) {
 113                         struct combine_diff_path *dpath;
 114                         struct diff_filepair *pair;
 115                         unsigned int wt_mode = 0;
 116                         int num_compare_stages = 0;
 117                         size_t path_len;
 118
 119                         path_len = ce_namelen(ce);
 120
 121                         dpath = xmalloc(combine_diff_path_size(5, path_len));
 122                         dpath->path = (char *) &(dpath->parent[5]);
 123
 124                         dpath->next = NULL;
 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                                 wt_mode = ce_mode_from_stat(ce, st.st_mode);
 134                         else {
 135                                 if (changed < 0) {
 136                                         perror(ce->name);
 137                                         continue;
 138                                 }
 139                                 wt_mode = 0;
 140                         }
 141                         dpath->mode = wt_mode;
 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                         pair = diff_unmerge(&revs->diffopt, ce->name);
 188                         if (wt_mode)
 189                                 pair->two->mode = wt_mode;
 190                         if (ce_stage(ce) != diff_unmerged_stage)
 191                                 continue;
 192                 }
 193
 194                 if (ce_uptodate(ce) || ce_skip_worktree(ce))
 195                         continue;
 196
 197                 /* If CE_VALID is set, don't look at workdir for file removal */
 198                 changed = (ce->ce_flags & CE_VALID) ? 0 : check_removed(ce, &st);
 199                 if (changed) {
 200                         if (changed < 0) {
 201                                 perror(ce->name);
 202                                 continue;
 203                         }
 204                         diff_addremove(&revs->diffopt, '-', ce->ce_mode,
 205                                        ce->sha1, !is_null_sha1(ce->sha1),
 206                                        ce->name, 0);
 207                         continue;
 208                 }
 209                 changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
 210                                                     ce_option, &dirty_submodule);
 211                 if (!changed && !dirty_submodule) {
 212                         ce_mark_uptodate(ce);
 213                         if (!DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
 214                                 continue;
 215                 }
 216                 oldmode = ce->ce_mode;
 217                 newmode = ce_mode_from_stat(ce, st.st_mode);
 218                 diff_change(&revs->diffopt, oldmode, newmode,
 219                             ce->sha1, (changed ? null_sha1 : ce->sha1),
 220                             !is_null_sha1(ce->sha1), (changed ? 0 : !is_null_sha1(ce->sha1)),
 221                             ce->name, 0, dirty_submodule);
 222
 223         }
 224         diffcore_std(&revs->diffopt);
 225         diff_flush(&revs->diffopt);
 226         return 0;
 227 }
 228
 229 /*
 230  * diff-index
 231  */
 232
 233 /* A file entry went away or appeared */
 234 static void diff_index_show_file(struct rev_info *revs,
 235                                  const char *prefix,
 236                                  const struct cache_entry *ce,
 237                                  const unsigned char *sha1, int sha1_valid,
 238                                  unsigned int mode,
 239                                  unsigned dirty_submodule)
 240 {
 241         diff_addremove(&revs->diffopt, prefix[0], mode,
 242                        sha1, sha1_valid, ce->name, dirty_submodule);
 243 }
 244
 245 static int get_stat_data(const struct cache_entry *ce,
 246                          const unsigned char **sha1p,
 247                          unsigned int *modep,
 248                          int cached, int match_missing,
 249                          unsigned *dirty_submodule, struct diff_options *diffopt)
 250 {
 251         const unsigned char *sha1 = ce->sha1;
 252         unsigned int mode = ce->ce_mode;
 253
 254         if (!cached && !ce_uptodate(ce)) {
 255                 int changed;
 256                 struct stat st;
 257                 changed = check_removed(ce, &st);
 258                 if (changed < 0)
 259                         return -1;
 260                 else if (changed) {
 261                         if (match_missing) {
 262                                 *sha1p = sha1;
 263                                 *modep = mode;
 264                                 return 0;
 265                         }
 266                         return -1;
 267                 }
 268                 changed = match_stat_with_submodule(diffopt, ce, &st,
 269                                                     0, dirty_submodule);
 270                 if (changed) {
 271                         mode = ce_mode_from_stat(ce, st.st_mode);
 272                         sha1 = null_sha1;
 273                 }
 274         }
 275
 276         *sha1p = sha1;
 277         *modep = mode;
 278         return 0;
 279 }
 280
 281 static void show_new_file(struct rev_info *revs,
 282                           const struct cache_entry *new,
 283                           int cached, int match_missing)
 284 {
 285         const unsigned char *sha1;
 286         unsigned int mode;
 287         unsigned dirty_submodule = 0;
 288
 289         /*
 290          * New file in the index: it might actually be different in
 291          * the working tree.
 292          */
 293         if (get_stat_data(new, &sha1, &mode, cached, match_missing,
 294             &dirty_submodule, &revs->diffopt) < 0)
 295                 return;
 296
 297         diff_index_show_file(revs, "+", new, sha1, !is_null_sha1(sha1), mode, dirty_submodule);
 298 }
 299
 300 static int show_modified(struct rev_info *revs,
 301                          const struct cache_entry *old,
 302                          const struct cache_entry *new,
 303                          int report_missing,
 304                          int cached, int match_missing)
 305 {
 306         unsigned int mode, oldmode;
 307         const unsigned char *sha1;
 308         unsigned dirty_submodule = 0;
 309
 310         if (get_stat_data(new, &sha1, &mode, cached, match_missing,
 311                           &dirty_submodule, &revs->diffopt) < 0) {
 312                 if (report_missing)
 313                         diff_index_show_file(revs, "-", old,
 314                                              old->sha1, 1, old->ce_mode, 0);
 315                 return -1;
 316         }
 317
 318         if (revs->combine_merges && !cached &&
 319             (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
 320                 struct combine_diff_path *p;
 321                 int pathlen = ce_namelen(new);
 322
 323                 p = xmalloc(combine_diff_path_size(2, pathlen));
 324                 p->path = (char *) &p->parent[2];
 325                 p->next = NULL;
 326                 memcpy(p->path, new->name, pathlen);
 327                 p->path[pathlen] = 0;
 328                 p->mode = mode;
 329                 hashclr(p->sha1);
 330                 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
 331                 p->parent[0].status = DIFF_STATUS_MODIFIED;
 332                 p->parent[0].mode = new->ce_mode;
 333                 hashcpy(p->parent[0].sha1, new->sha1);
 334                 p->parent[1].status = DIFF_STATUS_MODIFIED;
 335                 p->parent[1].mode = old->ce_mode;
 336                 hashcpy(p->parent[1].sha1, old->sha1);
 337                 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
 338                 free(p);
 339                 return 0;
 340         }
 341
 342         oldmode = old->ce_mode;
 343         if (mode == oldmode && !hashcmp(sha1, old->sha1) && !dirty_submodule &&
 344             !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
 345                 return 0;
 346
 347         diff_change(&revs->diffopt, oldmode, mode,
 348                     old->sha1, sha1, 1, !is_null_sha1(sha1),
 349                     old->name, 0, dirty_submodule);
 350         return 0;
 351 }
 352
 353 /*
 354  * This gets a mix of an existing index and a tree, one pathname entry
 355  * at a time. The index entry may be a single stage-0 one, but it could
 356  * also be multiple unmerged entries (in which case idx_pos/idx_nr will
 357  * give you the position and number of entries in the index).
 358  */
 359 static void do_oneway_diff(struct unpack_trees_options *o,
 360                            const struct cache_entry *idx,
 361                            const struct cache_entry *tree)
 362 {
 363         struct rev_info *revs = o->unpack_data;
 364         int match_missing, cached;
 365
 366         /* if the entry is not checked out, don't examine work tree */
 367         cached = o->index_only ||
 368                 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
 369         /*
 370          * Backward compatibility wart - "diff-index -m" does
 371          * not mean "do not ignore merges", but "match_missing".
 372          *
 373          * But with the revision flag parsing, that's found in
 374          * "!revs->ignore_merges".
 375          */
 376         match_missing = !revs->ignore_merges;
 377
 378         if (cached && idx && ce_stage(idx)) {
 379                 struct diff_filepair *pair;
 380                 pair = diff_unmerge(&revs->diffopt, idx->name);
 381                 if (tree)
 382                         fill_filespec(pair->one, tree->sha1, 1, tree->ce_mode);
 383                 return;
 384         }
 385
 386         /*
 387          * Something added to the tree?
 388          */
 389         if (!tree) {
 390                 show_new_file(revs, idx, cached, match_missing);
 391                 return;
 392         }
 393
 394         /*
 395          * Something removed from the tree?
 396          */
 397         if (!idx) {
 398                 diff_index_show_file(revs, "-", tree, tree->sha1, 1, tree->ce_mode, 0);
 399                 return;
 400         }
 401
 402         /* Show difference between old and new */
 403         show_modified(revs, tree, idx, 1, cached, match_missing);
 404 }
 405
 406 /*
 407  * The unpack_trees() interface is designed for merging, so
 408  * the different source entries are designed primarily for
 409  * the source trees, with the old index being really mainly
 410  * used for being replaced by the result.
 411  *
 412  * For diffing, the index is more important, and we only have a
 413  * single tree.
 414  *
 415  * We're supposed to advance o->pos to skip what we have already processed.
 416  *
 417  * This wrapper makes it all more readable, and takes care of all
 418  * the fairly complex unpack_trees() semantic requirements, including
 419  * the skipping, the path matching, the type conflict cases etc.
 420  */
 421 static int oneway_diff(const struct cache_entry * const *src,
 422                        struct unpack_trees_options *o)
 423 {
 424         const struct cache_entry *idx = src[0];
 425         const struct cache_entry *tree = src[1];
 426         struct rev_info *revs = o->unpack_data;
 427
 428         /*
 429          * Unpack-trees generates a DF/conflict entry if
 430          * there was a directory in the index and a tree
 431          * in the tree. From a diff standpoint, that's a
 432          * delete of the tree and a create of the file.
 433          */
 434         if (tree == o->df_conflict_entry)
 435                 tree = NULL;
 436
 437         if (ce_path_match(idx ? idx : tree, &revs->prune_data, NULL)) {
 438                 do_oneway_diff(o, idx, tree);
 439                 if (diff_can_quit_early(&revs->diffopt)) {
 440                         o->exiting_early = 1;
 441                         return -1;
 442                 }
 443         }
 444
 445         return 0;
 446 }
 447
 448 static int diff_cache(struct rev_info *revs,
 449                       const unsigned char *tree_sha1,
 450                       const char *tree_name,
 451                       int cached)
 452 {
 453         struct tree *tree;
 454         struct tree_desc t;
 455         struct unpack_trees_options opts;
 456
 457         tree = parse_tree_indirect(tree_sha1);
 458         if (!tree)
 459                 return error("bad tree object %s",
 460                              tree_name ? tree_name : sha1_to_hex(tree_sha1));
 461         memset(&opts, 0, sizeof(opts));
 462         opts.head_idx = 1;
 463         opts.index_only = cached;
 464         opts.diff_index_cached = (cached &&
 465                                   !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER));
 466         opts.merge = 1;
 467         opts.fn = oneway_diff;
 468         opts.unpack_data = revs;
 469         opts.src_index = &the_index;
 470         opts.dst_index = NULL;
 471         opts.pathspec = &revs->diffopt.pathspec;
 472         opts.pathspec->recursive = 1;
 473
 474         init_tree_desc(&t, tree->buffer, tree->size);
 475         return unpack_trees(1, &t, &opts);
 476 }
 477
 478 int run_diff_index(struct rev_info *revs, int cached)
 479 {
 480         struct object_array_entry *ent;
 481
 482         ent = revs->pending.objects;
 483         if (diff_cache(revs, ent->item->sha1, ent->name, cached))
 484                 exit(128);
 485
 486         diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
 487         diffcore_fix_diff_index(&revs->diffopt);
 488         diffcore_std(&revs->diffopt);
 489         diff_flush(&revs->diffopt);
 490         return 0;
 491 }
 492
 493 int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
 494 {
 495         struct rev_info revs;
 496
 497         init_revisions(&revs, NULL);
 498         copy_pathspec(&revs.prune_data, &opt->pathspec);
 499         revs.diffopt = *opt;
 500
 501         if (diff_cache(&revs, tree_sha1, NULL, 1))
 502                 exit(128);
 503         return 0;
 504 }
 505
 506 int index_differs_from(const char *def, int diff_flags)
 507 {
 508         struct rev_info rev;
 509         struct setup_revision_opt opt;
 510
 511         init_revisions(&rev, NULL);
 512         memset(&opt, 0, sizeof(opt));
 513         opt.def = def;
 514         setup_revisions(0, NULL, &rev, &opt);
 515         DIFF_OPT_SET(&rev.diffopt, QUICK);
 516         DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
 517         rev.diffopt.flags |= diff_flags;
 518         run_diff_index(&rev, 1);
 519         if (rev.pending.alloc)
 520                 free(rev.pending.objects);
 521         return (DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES) != 0);
 522 }