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                 unsigned int oldmode, newmode;
 101                 struct cache_entry *ce = active_cache[i];
 102                 int changed;
 103                 unsigned dirty_submodule = 0;
 104                 const unsigned char *old_sha1, *new_sha1;
 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                         struct stat st;
 119
 120                         path_len = ce_namelen(ce);
 121
 122                         dpath = xmalloc(combine_diff_path_size(5, path_len));
 123                         dpath->path = (char *) &(dpath->parent[5]);
 124
 125                         dpath->next = NULL;
 126                         memcpy(dpath->path, ce->name, path_len);
 127                         dpath->path[path_len] = '\0';
 128                         hashclr(dpath->sha1);
 129                         memset(&(dpath->parent[0]), 0,
 130                                sizeof(struct combine_diff_parent)*5);
 131
 132                         changed = check_removed(ce, &st);
 133                         if (!changed)
 134                                 wt_mode = ce_mode_from_stat(ce, st.st_mode);
 135                         else {
 136                                 if (changed < 0) {
 137                                         perror(ce->name);
 138                                         continue;
 139                                 }
 140                                 wt_mode = 0;
 141                         }
 142                         dpath->mode = wt_mode;
 143
 144                         while (i < entries) {
 145                                 struct cache_entry *nce = active_cache[i];
 146                                 int stage;
 147
 148                                 if (strcmp(ce->name, nce->name))
 149                                         break;
 150
 151                                 /* Stage #2 (ours) is the first parent,
 152                                  * stage #3 (theirs) is the second.
 153                                  */
 154                                 stage = ce_stage(nce);
 155                                 if (2 <= stage) {
 156                                         int mode = nce->ce_mode;
 157                                         num_compare_stages++;
 158                                         hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
 159                                         dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
 160                                         dpath->parent[stage-2].status =
 161                                                 DIFF_STATUS_MODIFIED;
 162                                 }
 163
 164                                 /* diff against the proper unmerged stage */
 165                                 if (stage == diff_unmerged_stage)
 166                                         ce = nce;
 167                                 i++;
 168                         }
 169                         /*
 170                          * Compensate for loop update
 171                          */
 172                         i--;
 173
 174                         if (revs->combine_merges && num_compare_stages == 2) {
 175                                 show_combined_diff(dpath, 2,
 176                                                    revs->dense_combined_merges,
 177                                                    revs);
 178                                 free(dpath);
 179                                 continue;
 180                         }
 181                         free(dpath);
 182                         dpath = NULL;
 183
 184                         /*
 185                          * Show the diff for the 'ce' if we found the one
 186                          * from the desired stage.
 187                          */
 188                         pair = diff_unmerge(&revs->diffopt, ce->name);
 189                         if (wt_mode)
 190                                 pair->two->mode = wt_mode;
 191                         if (ce_stage(ce) != diff_unmerged_stage)
 192                                 continue;
 193                 }
 194
 195                 if (ce_uptodate(ce) || ce_skip_worktree(ce))
 196                         continue;
 197
 198                 /* If CE_VALID is set, don't look at workdir for file removal */
 199                 if (ce->ce_flags & CE_VALID) {
 200                         changed = 0;
 201                         newmode = ce->ce_mode;
 202                 } else {
 203                         struct stat st;
 204
 205                         changed = check_removed(ce, &st);
 206                         if (changed) {
 207                                 if (changed < 0) {
 208                                         perror(ce->name);
 209                                         continue;
 210                                 }
 211                                 diff_addremove(&revs->diffopt, '-', ce->ce_mode,
 212                                                ce->sha1, !is_null_sha1(ce->sha1),
 213                                                ce->name, 0);
 214                                 continue;
 215                         }
 216
 217                         changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
 218                                                             ce_option, &dirty_submodule);
 219                         newmode = ce_mode_from_stat(ce, st.st_mode);
 220                 }
 221
 222                 if (!changed && !dirty_submodule) {
 223                         ce_mark_uptodate(ce);
 224                         if (!DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
 225                                 continue;
 226                 }
 227                 oldmode = ce->ce_mode;
 228                 old_sha1 = ce->sha1;
 229                 new_sha1 = changed ? null_sha1 : ce->sha1;
 230                 diff_change(&revs->diffopt, oldmode, newmode,
 231                             old_sha1, new_sha1,
 232                             !is_null_sha1(old_sha1),
 233                             !is_null_sha1(new_sha1),
 234                             ce->name, 0, dirty_submodule);
 235
 236         }
 237         diffcore_std(&revs->diffopt);
 238         diff_flush(&revs->diffopt);
 239         return 0;
 240 }
 241
 242 /*
 243  * diff-index
 244  */
 245
 246 /* A file entry went away or appeared */
 247 static void diff_index_show_file(struct rev_info *revs,
 248                                  const char *prefix,
 249                                  const struct cache_entry *ce,
 250                                  const unsigned char *sha1, int sha1_valid,
 251                                  unsigned int mode,
 252                                  unsigned dirty_submodule)
 253 {
 254         diff_addremove(&revs->diffopt, prefix[0], mode,
 255                        sha1, sha1_valid, ce->name, dirty_submodule);
 256 }
 257
 258 static int get_stat_data(const struct cache_entry *ce,
 259                          const unsigned char **sha1p,
 260                          unsigned int *modep,
 261                          int cached, int match_missing,
 262                          unsigned *dirty_submodule, struct diff_options *diffopt)
 263 {
 264         const unsigned char *sha1 = ce->sha1;
 265         unsigned int mode = ce->ce_mode;
 266
 267         if (!cached && !ce_uptodate(ce)) {
 268                 int changed;
 269                 struct stat st;
 270                 changed = check_removed(ce, &st);
 271                 if (changed < 0)
 272                         return -1;
 273                 else if (changed) {
 274                         if (match_missing) {
 275                                 *sha1p = sha1;
 276                                 *modep = mode;
 277                                 return 0;
 278                         }
 279                         return -1;
 280                 }
 281                 changed = match_stat_with_submodule(diffopt, ce, &st,
 282                                                     0, dirty_submodule);
 283                 if (changed) {
 284                         mode = ce_mode_from_stat(ce, st.st_mode);
 285                         sha1 = null_sha1;
 286                 }
 287         }
 288
 289         *sha1p = sha1;
 290         *modep = mode;
 291         return 0;
 292 }
 293
 294 static void show_new_file(struct rev_info *revs,
 295                           const struct cache_entry *new,
 296                           int cached, int match_missing)
 297 {
 298         const unsigned char *sha1;
 299         unsigned int mode;
 300         unsigned dirty_submodule = 0;
 301
 302         /*
 303          * New file in the index: it might actually be different in
 304          * the working tree.
 305          */
 306         if (get_stat_data(new, &sha1, &mode, cached, match_missing,
 307             &dirty_submodule, &revs->diffopt) < 0)
 308                 return;
 309
 310         diff_index_show_file(revs, "+", new, sha1, !is_null_sha1(sha1), mode, dirty_submodule);
 311 }
 312
 313 static int show_modified(struct rev_info *revs,
 314                          const struct cache_entry *old,
 315                          const struct cache_entry *new,
 316                          int report_missing,
 317                          int cached, int match_missing)
 318 {
 319         unsigned int mode, oldmode;
 320         const unsigned char *sha1;
 321         unsigned dirty_submodule = 0;
 322
 323         if (get_stat_data(new, &sha1, &mode, cached, match_missing,
 324                           &dirty_submodule, &revs->diffopt) < 0) {
 325                 if (report_missing)
 326                         diff_index_show_file(revs, "-", old,
 327                                              old->sha1, 1, old->ce_mode, 0);
 328                 return -1;
 329         }
 330
 331         if (revs->combine_merges && !cached &&
 332             (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
 333                 struct combine_diff_path *p;
 334                 int pathlen = ce_namelen(new);
 335
 336                 p = xmalloc(combine_diff_path_size(2, pathlen));
 337                 p->path = (char *) &p->parent[2];
 338                 p->next = NULL;
 339                 memcpy(p->path, new->name, pathlen);
 340                 p->path[pathlen] = 0;
 341                 p->mode = mode;
 342                 hashclr(p->sha1);
 343                 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
 344                 p->parent[0].status = DIFF_STATUS_MODIFIED;
 345                 p->parent[0].mode = new->ce_mode;
 346                 hashcpy(p->parent[0].sha1, new->sha1);
 347                 p->parent[1].status = DIFF_STATUS_MODIFIED;
 348                 p->parent[1].mode = old->ce_mode;
 349                 hashcpy(p->parent[1].sha1, old->sha1);
 350                 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
 351                 free(p);
 352                 return 0;
 353         }
 354
 355         oldmode = old->ce_mode;
 356         if (mode == oldmode && !hashcmp(sha1, old->sha1) && !dirty_submodule &&
 357             !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
 358                 return 0;
 359
 360         diff_change(&revs->diffopt, oldmode, mode,
 361                     old->sha1, sha1, 1, !is_null_sha1(sha1),
 362                     old->name, 0, dirty_submodule);
 363         return 0;
 364 }
 365
 366 /*
 367  * This gets a mix of an existing index and a tree, one pathname entry
 368  * at a time. The index entry may be a single stage-0 one, but it could
 369  * also be multiple unmerged entries (in which case idx_pos/idx_nr will
 370  * give you the position and number of entries in the index).
 371  */
 372 static void do_oneway_diff(struct unpack_trees_options *o,
 373                            const struct cache_entry *idx,
 374                            const struct cache_entry *tree)
 375 {
 376         struct rev_info *revs = o->unpack_data;
 377         int match_missing, cached;
 378
 379         /* if the entry is not checked out, don't examine work tree */
 380         cached = o->index_only ||
 381                 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
 382         /*
 383          * Backward compatibility wart - "diff-index -m" does
 384          * not mean "do not ignore merges", but "match_missing".
 385          *
 386          * But with the revision flag parsing, that's found in
 387          * "!revs->ignore_merges".
 388          */
 389         match_missing = !revs->ignore_merges;
 390
 391         if (cached && idx && ce_stage(idx)) {
 392                 struct diff_filepair *pair;
 393                 pair = diff_unmerge(&revs->diffopt, idx->name);
 394                 if (tree)
 395                         fill_filespec(pair->one, tree->sha1, 1, tree->ce_mode);
 396                 return;
 397         }
 398
 399         /*
 400          * Something added to the tree?
 401          */
 402         if (!tree) {
 403                 show_new_file(revs, idx, cached, match_missing);
 404                 return;
 405         }
 406
 407         /*
 408          * Something removed from the tree?
 409          */
 410         if (!idx) {
 411                 diff_index_show_file(revs, "-", tree, tree->sha1, 1, tree->ce_mode, 0);
 412                 return;
 413         }
 414
 415         /* Show difference between old and new */
 416         show_modified(revs, tree, idx, 1, cached, match_missing);
 417 }
 418
 419 /*
 420  * The unpack_trees() interface is designed for merging, so
 421  * the different source entries are designed primarily for
 422  * the source trees, with the old index being really mainly
 423  * used for being replaced by the result.
 424  *
 425  * For diffing, the index is more important, and we only have a
 426  * single tree.
 427  *
 428  * We're supposed to advance o->pos to skip what we have already processed.
 429  *
 430  * This wrapper makes it all more readable, and takes care of all
 431  * the fairly complex unpack_trees() semantic requirements, including
 432  * the skipping, the path matching, the type conflict cases etc.
 433  */
 434 static int oneway_diff(const struct cache_entry * const *src,
 435                        struct unpack_trees_options *o)
 436 {
 437         const struct cache_entry *idx = src[0];
 438         const struct cache_entry *tree = src[1];
 439         struct rev_info *revs = o->unpack_data;
 440
 441         /*
 442          * Unpack-trees generates a DF/conflict entry if
 443          * there was a directory in the index and a tree
 444          * in the tree. From a diff standpoint, that's a
 445          * delete of the tree and a create of the file.
 446          */
 447         if (tree == o->df_conflict_entry)
 448                 tree = NULL;
 449
 450         if (ce_path_match(idx ? idx : tree, &revs->prune_data, NULL)) {
 451                 do_oneway_diff(o, idx, tree);
 452                 if (diff_can_quit_early(&revs->diffopt)) {
 453                         o->exiting_early = 1;
 454                         return -1;
 455                 }
 456         }
 457
 458         return 0;
 459 }
 460
 461 static int diff_cache(struct rev_info *revs,
 462                       const unsigned char *tree_sha1,
 463                       const char *tree_name,
 464                       int cached)
 465 {
 466         struct tree *tree;
 467         struct tree_desc t;
 468         struct unpack_trees_options opts;
 469
 470         tree = parse_tree_indirect(tree_sha1);
 471         if (!tree)
 472                 return error("bad tree object %s",
 473                              tree_name ? tree_name : sha1_to_hex(tree_sha1));
 474         memset(&opts, 0, sizeof(opts));
 475         opts.head_idx = 1;
 476         opts.index_only = cached;
 477         opts.diff_index_cached = (cached &&
 478                                   !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER));
 479         opts.merge = 1;
 480         opts.fn = oneway_diff;
 481         opts.unpack_data = revs;
 482         opts.src_index = &the_index;
 483         opts.dst_index = NULL;
 484         opts.pathspec = &revs->diffopt.pathspec;
 485         opts.pathspec->recursive = 1;
 486
 487         init_tree_desc(&t, tree->buffer, tree->size);
 488         return unpack_trees(1, &t, &opts);
 489 }
 490
 491 int run_diff_index(struct rev_info *revs, int cached)
 492 {
 493         struct object_array_entry *ent;
 494
 495         ent = revs->pending.objects;
 496         if (diff_cache(revs, ent->item->sha1, ent->name, cached))
 497                 exit(128);
 498
 499         diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
 500         diffcore_fix_diff_index(&revs->diffopt);
 501         diffcore_std(&revs->diffopt);
 502         diff_flush(&revs->diffopt);
 503         return 0;
 504 }
 505
 506 int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
 507 {
 508         struct rev_info revs;
 509
 510         init_revisions(&revs, NULL);
 511         copy_pathspec(&revs.prune_data, &opt->pathspec);
 512         revs.diffopt = *opt;
 513
 514         if (diff_cache(&revs, tree_sha1, NULL, 1))
 515                 exit(128);
 516         return 0;
 517 }
 518
 519 int index_differs_from(const char *def, int diff_flags)
 520 {
 521         struct rev_info rev;
 522         struct setup_revision_opt opt;
 523
 524         init_revisions(&rev, NULL);
 525         memset(&opt, 0, sizeof(opt));
 526         opt.def = def;
 527         setup_revisions(0, NULL, &rev, &opt);
 528         DIFF_OPT_SET(&rev.diffopt, QUICK);
 529         DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
 530         rev.diffopt.flags |= diff_flags;
 531         run_diff_index(&rev, 1);
 532         if (rev.pending.alloc)
 533                 free(rev.pending.objects);
 534         return (DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES) != 0);
 535 }