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                                      const struct cache_entry *ce,
  68                                      struct stat *st, unsigned ce_option,
  69                                      unsigned *dirty_submodule)
  70 {
  71         int changed = ce_match_stat(ce, st, ce_option);
  72         if (S_ISGITLINK(ce->ce_mode)) {
  73                 unsigned orig_flags = diffopt->flags;
  74                 if (!DIFF_OPT_TST(diffopt, OVERRIDE_SUBMODULE_CONFIG))
  75                         set_diffopt_flags_from_submodule_config(diffopt, ce->name);
  76                 if (DIFF_OPT_TST(diffopt, IGNORE_SUBMODULES))
  77                         changed = 0;
  78                 else if (!DIFF_OPT_TST(diffopt, IGNORE_DIRTY_SUBMODULES)
  79                     && (!changed || DIFF_OPT_TST(diffopt, DIRTY_SUBMODULES)))
  80                         *dirty_submodule = is_submodule_modified(ce->name, DIFF_OPT_TST(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES));
  81                 diffopt->flags = orig_flags;
  82         }
  83         return changed;
  84 }
  85
  86 int run_diff_files(struct rev_info *revs, unsigned int option)
  87 {
  88         int entries, i;
  89         int diff_unmerged_stage = revs->max_count;
  90         int silent_on_removed = option & DIFF_SILENT_ON_REMOVED;
  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))
 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                         dpath->len = path_len;
 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                                 if (silent_on_removed)
 141                                         continue;
 142                                 wt_mode = 0;
 143                         }
 144                         dpath->mode = wt_mode;
 145
 146                         while (i < entries) {
 147                                 struct cache_entry *nce = active_cache[i];
 148                                 int stage;
 149
 150                                 if (strcmp(ce->name, nce->name))
 151                                         break;
 152
 153                                 /* Stage #2 (ours) is the first parent,
 154                                  * stage #3 (theirs) is the second.
 155                                  */
 156                                 stage = ce_stage(nce);
 157                                 if (2 <= stage) {
 158                                         int mode = nce->ce_mode;
 159                                         num_compare_stages++;
 160                                         hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
 161                                         dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
 162                                         dpath->parent[stage-2].status =
 163                                                 DIFF_STATUS_MODIFIED;
 164                                 }
 165
 166                                 /* diff against the proper unmerged stage */
 167                                 if (stage == diff_unmerged_stage)
 168                                         ce = nce;
 169                                 i++;
 170                         }
 171                         /*
 172                          * Compensate for loop update
 173                          */
 174                         i--;
 175
 176                         if (revs->combine_merges && num_compare_stages == 2) {
 177                                 show_combined_diff(dpath, 2,
 178                                                    revs->dense_combined_merges,
 179                                                    revs);
 180                                 free(dpath);
 181                                 continue;
 182                         }
 183                         free(dpath);
 184                         dpath = NULL;
 185
 186                         /*
 187                          * Show the diff for the 'ce' if we found the one
 188                          * from the desired stage.
 189                          */
 190                         pair = diff_unmerge(&revs->diffopt, ce->name);
 191                         if (wt_mode)
 192                                 pair->two->mode = wt_mode;
 193                         if (ce_stage(ce) != diff_unmerged_stage)
 194                                 continue;
 195                 }
 196
 197                 if (ce_uptodate(ce) || ce_skip_worktree(ce))
 198                         continue;
 199
 200                 /* If CE_VALID is set, don't look at workdir for file removal */
 201                 changed = (ce->ce_flags & CE_VALID) ? 0 : check_removed(ce, &st);
 202                 if (changed) {
 203                         if (changed < 0) {
 204                                 perror(ce->name);
 205                                 continue;
 206                         }
 207                         if (silent_on_removed)
 208                                 continue;
 209                         diff_addremove(&revs->diffopt, '-', ce->ce_mode,
 210                                        ce->sha1, !is_null_sha1(ce->sha1),
 211                                        ce->name, 0);
 212                         continue;
 213                 }
 214                 changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
 215                                                     ce_option, &dirty_submodule);
 216                 if (!changed && !dirty_submodule) {
 217                         ce_mark_uptodate(ce);
 218                         if (!DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
 219                                 continue;
 220                 }
 221                 oldmode = ce->ce_mode;
 222                 newmode = ce_mode_from_stat(ce, st.st_mode);
 223                 diff_change(&revs->diffopt, oldmode, newmode,
 224                             ce->sha1, (changed ? null_sha1 : ce->sha1),
 225                             !is_null_sha1(ce->sha1), (changed ? 0 : !is_null_sha1(ce->sha1)),
 226                             ce->name, 0, dirty_submodule);
 227
 228         }
 229         diffcore_std(&revs->diffopt);
 230         diff_flush(&revs->diffopt);
 231         return 0;
 232 }
 233
 234 /*
 235  * diff-index
 236  */
 237
 238 /* A file entry went away or appeared */
 239 static void diff_index_show_file(struct rev_info *revs,
 240                                  const char *prefix,
 241                                  const struct cache_entry *ce,
 242                                  const unsigned char *sha1, int sha1_valid,
 243                                  unsigned int mode,
 244                                  unsigned dirty_submodule)
 245 {
 246         diff_addremove(&revs->diffopt, prefix[0], mode,
 247                        sha1, sha1_valid, ce->name, dirty_submodule);
 248 }
 249
 250 static int get_stat_data(const struct cache_entry *ce,
 251                          const unsigned char **sha1p,
 252                          unsigned int *modep,
 253                          int cached, int match_missing,
 254                          unsigned *dirty_submodule, struct diff_options *diffopt)
 255 {
 256         const unsigned char *sha1 = ce->sha1;
 257         unsigned int mode = ce->ce_mode;
 258
 259         if (!cached && !ce_uptodate(ce)) {
 260                 int changed;
 261                 struct stat st;
 262                 changed = check_removed(ce, &st);
 263                 if (changed < 0)
 264                         return -1;
 265                 else if (changed) {
 266                         if (match_missing) {
 267                                 *sha1p = sha1;
 268                                 *modep = mode;
 269                                 return 0;
 270                         }
 271                         return -1;
 272                 }
 273                 changed = match_stat_with_submodule(diffopt, ce, &st,
 274                                                     0, dirty_submodule);
 275                 if (changed) {
 276                         mode = ce_mode_from_stat(ce, st.st_mode);
 277                         sha1 = null_sha1;
 278                 }
 279         }
 280
 281         *sha1p = sha1;
 282         *modep = mode;
 283         return 0;
 284 }
 285
 286 static void show_new_file(struct rev_info *revs,
 287                           const struct cache_entry *new,
 288                           int cached, int match_missing)
 289 {
 290         const unsigned char *sha1;
 291         unsigned int mode;
 292         unsigned dirty_submodule = 0;
 293
 294         /*
 295          * New file in the index: it might actually be different in
 296          * the working tree.
 297          */
 298         if (get_stat_data(new, &sha1, &mode, cached, match_missing,
 299             &dirty_submodule, &revs->diffopt) < 0)
 300                 return;
 301
 302         diff_index_show_file(revs, "+", new, sha1, !is_null_sha1(sha1), mode, dirty_submodule);
 303 }
 304
 305 static int show_modified(struct rev_info *revs,
 306                          const struct cache_entry *old,
 307                          const struct cache_entry *new,
 308                          int report_missing,
 309                          int cached, int match_missing)
 310 {
 311         unsigned int mode, oldmode;
 312         const unsigned char *sha1;
 313         unsigned dirty_submodule = 0;
 314
 315         if (get_stat_data(new, &sha1, &mode, cached, match_missing,
 316                           &dirty_submodule, &revs->diffopt) < 0) {
 317                 if (report_missing)
 318                         diff_index_show_file(revs, "-", old,
 319                                              old->sha1, 1, old->ce_mode, 0);
 320                 return -1;
 321         }
 322
 323         if (revs->combine_merges && !cached &&
 324             (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
 325                 struct combine_diff_path *p;
 326                 int pathlen = ce_namelen(new);
 327
 328                 p = xmalloc(combine_diff_path_size(2, pathlen));
 329                 p->path = (char *) &p->parent[2];
 330                 p->next = NULL;
 331                 p->len = pathlen;
 332                 memcpy(p->path, new->name, pathlen);
 333                 p->path[pathlen] = 0;
 334                 p->mode = mode;
 335                 hashclr(p->sha1);
 336                 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
 337                 p->parent[0].status = DIFF_STATUS_MODIFIED;
 338                 p->parent[0].mode = new->ce_mode;
 339                 hashcpy(p->parent[0].sha1, new->sha1);
 340                 p->parent[1].status = DIFF_STATUS_MODIFIED;
 341                 p->parent[1].mode = old->ce_mode;
 342                 hashcpy(p->parent[1].sha1, old->sha1);
 343                 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
 344                 free(p);
 345                 return 0;
 346         }
 347
 348         oldmode = old->ce_mode;
 349         if (mode == oldmode && !hashcmp(sha1, old->sha1) && !dirty_submodule &&
 350             !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
 351                 return 0;
 352
 353         diff_change(&revs->diffopt, oldmode, mode,
 354                     old->sha1, sha1, 1, !is_null_sha1(sha1),
 355                     old->name, 0, dirty_submodule);
 356         return 0;
 357 }
 358
 359 /*
 360  * This gets a mix of an existing index and a tree, one pathname entry
 361  * at a time. The index entry may be a single stage-0 one, but it could
 362  * also be multiple unmerged entries (in which case idx_pos/idx_nr will
 363  * give you the position and number of entries in the index).
 364  */
 365 static void do_oneway_diff(struct unpack_trees_options *o,
 366                            const struct cache_entry *idx,
 367                            const struct cache_entry *tree)
 368 {
 369         struct rev_info *revs = o->unpack_data;
 370         int match_missing, cached;
 371
 372         /* if the entry is not checked out, don't examine work tree */
 373         cached = o->index_only ||
 374                 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
 375         /*
 376          * Backward compatibility wart - "diff-index -m" does
 377          * not mean "do not ignore merges", but "match_missing".
 378          *
 379          * But with the revision flag parsing, that's found in
 380          * "!revs->ignore_merges".
 381          */
 382         match_missing = !revs->ignore_merges;
 383
 384         if (cached && idx && ce_stage(idx)) {
 385                 struct diff_filepair *pair;
 386                 pair = diff_unmerge(&revs->diffopt, idx->name);
 387                 if (tree)
 388                         fill_filespec(pair->one, tree->sha1, 1, tree->ce_mode);
 389                 return;
 390         }
 391
 392         /*
 393          * Something added to the tree?
 394          */
 395         if (!tree) {
 396                 show_new_file(revs, idx, cached, match_missing);
 397                 return;
 398         }
 399
 400         /*
 401          * Something removed from the tree?
 402          */
 403         if (!idx) {
 404                 diff_index_show_file(revs, "-", tree, tree->sha1, 1, tree->ce_mode, 0);
 405                 return;
 406         }
 407
 408         /* Show difference between old and new */
 409         show_modified(revs, tree, idx, 1, cached, match_missing);
 410 }
 411
 412 /*
 413  * The unpack_trees() interface is designed for merging, so
 414  * the different source entries are designed primarily for
 415  * the source trees, with the old index being really mainly
 416  * used for being replaced by the result.
 417  *
 418  * For diffing, the index is more important, and we only have a
 419  * single tree.
 420  *
 421  * We're supposed to advance o->pos to skip what we have already processed.
 422  *
 423  * This wrapper makes it all more readable, and takes care of all
 424  * the fairly complex unpack_trees() semantic requirements, including
 425  * the skipping, the path matching, the type conflict cases etc.
 426  */
 427 static int oneway_diff(const struct cache_entry * const *src,
 428                        struct unpack_trees_options *o)
 429 {
 430         const struct cache_entry *idx = src[0];
 431         const struct cache_entry *tree = src[1];
 432         struct rev_info *revs = o->unpack_data;
 433
 434         /*
 435          * Unpack-trees generates a DF/conflict entry if
 436          * there was a directory in the index and a tree
 437          * in the tree. From a diff standpoint, that's a
 438          * delete of the tree and a create of the file.
 439          */
 440         if (tree == o->df_conflict_entry)
 441                 tree = NULL;
 442
 443         if (ce_path_match(idx ? idx : tree, &revs->prune_data)) {
 444                 do_oneway_diff(o, idx, tree);
 445                 if (diff_can_quit_early(&revs->diffopt)) {
 446                         o->exiting_early = 1;
 447                         return -1;
 448                 }
 449         }
 450
 451         return 0;
 452 }
 453
 454 static int diff_cache(struct rev_info *revs,
 455                       const unsigned char *tree_sha1,
 456                       const char *tree_name,
 457                       int cached)
 458 {
 459         struct tree *tree;
 460         struct tree_desc t;
 461         struct unpack_trees_options opts;
 462
 463         tree = parse_tree_indirect(tree_sha1);
 464         if (!tree)
 465                 return error("bad tree object %s",
 466                              tree_name ? tree_name : sha1_to_hex(tree_sha1));
 467         memset(&opts, 0, sizeof(opts));
 468         opts.head_idx = 1;
 469         opts.index_only = cached;
 470         opts.diff_index_cached = (cached &&
 471                                   !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER));
 472         opts.merge = 1;
 473         opts.fn = oneway_diff;
 474         opts.unpack_data = revs;
 475         opts.src_index = &the_index;
 476         opts.dst_index = NULL;
 477         opts.pathspec = &revs->diffopt.pathspec;
 478         opts.pathspec->recursive = 1;
 479
 480         init_tree_desc(&t, tree->buffer, tree->size);
 481         return unpack_trees(1, &t, &opts);
 482 }
 483
 484 int run_diff_index(struct rev_info *revs, int cached)
 485 {
 486         struct object_array_entry *ent;
 487
 488         ent = revs->pending.objects;
 489         if (diff_cache(revs, ent->item->sha1, ent->name, cached))
 490                 exit(128);
 491
 492         diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
 493         diffcore_fix_diff_index(&revs->diffopt);
 494         diffcore_std(&revs->diffopt);
 495         diff_flush(&revs->diffopt);
 496         return 0;
 497 }
 498
 499 int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
 500 {
 501         struct rev_info revs;
 502
 503         init_revisions(&revs, NULL);
 504         copy_pathspec(&revs.prune_data, &opt->pathspec);
 505         revs.diffopt = *opt;
 506
 507         if (diff_cache(&revs, tree_sha1, NULL, 1))
 508                 exit(128);
 509         return 0;
 510 }
 511
 512 int index_differs_from(const char *def, int diff_flags)
 513 {
 514         struct rev_info rev;
 515         struct setup_revision_opt opt;
 516
 517         init_revisions(&rev, NULL);
 518         memset(&opt, 0, sizeof(opt));
 519         opt.def = def;
 520         setup_revisions(0, NULL, &rev, &opt);
 521         DIFF_OPT_SET(&rev.diffopt, QUICK);
 522         DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
 523         rev.diffopt.flags |= diff_flags;
 524         run_diff_index(&rev, 1);
 525         if (rev.pending.alloc)
 526                 free(rev.pending.objects);
 527         return (DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES) != 0);
 528 }