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_can_quit_early(&revs->diffopt))
 106                         break;
 107
 108                 if (!ce_path_match(ce, &revs->prune_data))
 109                         continue;
 110
 111                 if (ce_stage(ce)) {
 112                         struct combine_diff_path *dpath;
 113                         struct diff_filepair *pair;
 114                         unsigned int wt_mode = 0;
 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                                 wt_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                                 wt_mode = 0;
 142                         }
 143                         dpath->mode = wt_mode;
 144
 145                         while (i < entries) {
 146                                 struct cache_entry *nce = active_cache[i];
 147                                 int stage;
 148
 149                                 if (strcmp(ce->name, nce->name))
 150                                         break;
 151
 152                                 /* Stage #2 (ours) is the first parent,
 153                                  * stage #3 (theirs) is the second.
 154                                  */
 155                                 stage = ce_stage(nce);
 156                                 if (2 <= stage) {
 157                                         int mode = nce->ce_mode;
 158                                         num_compare_stages++;
 159                                         hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
 160                                         dpath->parent[stage-2].mode = ce_mode_from_stat(nce, mode);
 161                                         dpath->parent[stage-2].status =
 162                                                 DIFF_STATUS_MODIFIED;
 163                                 }
 164
 165                                 /* diff against the proper unmerged stage */
 166                                 if (stage == diff_unmerged_stage)
 167                                         ce = nce;
 168                                 i++;
 169                         }
 170                         /*
 171                          * Compensate for loop update
 172                          */
 173                         i--;
 174
 175                         if (revs->combine_merges && num_compare_stages == 2) {
 176                                 show_combined_diff(dpath, 2,
 177                                                    revs->dense_combined_merges,
 178                                                    revs);
 179                                 free(dpath);
 180                                 continue;
 181                         }
 182                         free(dpath);
 183                         dpath = NULL;
 184
 185                         /*
 186                          * Show the diff for the 'ce' if we found the one
 187                          * from the desired stage.
 188                          */
 189                         pair = diff_unmerge(&revs->diffopt, ce->name);
 190                         if (wt_mode)
 191                                 pair->two->mode = wt_mode;
 192                         if (ce_stage(ce) != diff_unmerged_stage)
 193                                 continue;
 194                 }
 195
 196                 if (ce_uptodate(ce) || ce_skip_worktree(ce))
 197                         continue;
 198
 199                 /* If CE_VALID is set, don't look at workdir for file removal */
 200                 changed = (ce->ce_flags & CE_VALID) ? 0 : check_removed(ce, &st);
 201                 if (changed) {
 202                         if (changed < 0) {
 203                                 perror(ce->name);
 204                                 continue;
 205                         }
 206                         if (silent_on_removed)
 207                                 continue;
 208                         diff_addremove(&revs->diffopt, '-', ce->ce_mode,
 209                                        ce->sha1, ce->name, 0);
 210                         continue;
 211                 }
 212                 changed = match_stat_with_submodule(&revs->diffopt, ce, &st,
 213                                                     ce_option, &dirty_submodule);
 214                 if (!changed && !dirty_submodule) {
 215                         ce_mark_uptodate(ce);
 216                         if (!DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
 217                                 continue;
 218                 }
 219                 oldmode = ce->ce_mode;
 220                 newmode = ce_mode_from_stat(ce, st.st_mode);
 221                 diff_change(&revs->diffopt, oldmode, newmode,
 222                             ce->sha1, (changed ? null_sha1 : ce->sha1),
 223                             ce->name, 0, dirty_submodule);
 224
 225         }
 226         diffcore_std(&revs->diffopt);
 227         diff_flush(&revs->diffopt);
 228         return 0;
 229 }
 230
 231 /*
 232  * diff-index
 233  */
 234
 235 /* A file entry went away or appeared */
 236 static void diff_index_show_file(struct rev_info *revs,
 237                                  const char *prefix,
 238                                  struct cache_entry *ce,
 239                                  const unsigned char *sha1, unsigned int mode,
 240                                  unsigned dirty_submodule)
 241 {
 242         diff_addremove(&revs->diffopt, prefix[0], mode,
 243                        sha1, ce->name, dirty_submodule);
 244 }
 245
 246 static int get_stat_data(struct cache_entry *ce,
 247                          const unsigned char **sha1p,
 248                          unsigned int *modep,
 249                          int cached, int match_missing,
 250                          unsigned *dirty_submodule, struct diff_options *diffopt)
 251 {
 252         const unsigned char *sha1 = ce->sha1;
 253         unsigned int mode = ce->ce_mode;
 254
 255         if (!cached && !ce_uptodate(ce)) {
 256                 int changed;
 257                 struct stat st;
 258                 changed = check_removed(ce, &st);
 259                 if (changed < 0)
 260                         return -1;
 261                 else if (changed) {
 262                         if (match_missing) {
 263                                 *sha1p = sha1;
 264                                 *modep = mode;
 265                                 return 0;
 266                         }
 267                         return -1;
 268                 }
 269                 changed = match_stat_with_submodule(diffopt, ce, &st,
 270                                                     0, dirty_submodule);
 271                 if (changed) {
 272                         mode = ce_mode_from_stat(ce, st.st_mode);
 273                         sha1 = null_sha1;
 274                 }
 275         }
 276
 277         *sha1p = sha1;
 278         *modep = mode;
 279         return 0;
 280 }
 281
 282 static void show_new_file(struct rev_info *revs,
 283                           struct cache_entry *new,
 284                           int cached, int match_missing)
 285 {
 286         const unsigned char *sha1;
 287         unsigned int mode;
 288         unsigned dirty_submodule = 0;
 289
 290         /*
 291          * New file in the index: it might actually be different in
 292          * the working copy.
 293          */
 294         if (get_stat_data(new, &sha1, &mode, cached, match_missing,
 295             &dirty_submodule, &revs->diffopt) < 0)
 296                 return;
 297
 298         diff_index_show_file(revs, "+", new, sha1, mode, dirty_submodule);
 299 }
 300
 301 static int show_modified(struct rev_info *revs,
 302                          struct cache_entry *old,
 303                          struct cache_entry *new,
 304                          int report_missing,
 305                          int cached, int match_missing)
 306 {
 307         unsigned int mode, oldmode;
 308         const unsigned char *sha1;
 309         unsigned dirty_submodule = 0;
 310
 311         if (get_stat_data(new, &sha1, &mode, cached, match_missing,
 312                           &dirty_submodule, &revs->diffopt) < 0) {
 313                 if (report_missing)
 314                         diff_index_show_file(revs, "-", old,
 315                                              old->sha1, old->ce_mode, 0);
 316                 return -1;
 317         }
 318
 319         if (revs->combine_merges && !cached &&
 320             (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
 321                 struct combine_diff_path *p;
 322                 int pathlen = ce_namelen(new);
 323
 324                 p = xmalloc(combine_diff_path_size(2, pathlen));
 325                 p->path = (char *) &p->parent[2];
 326                 p->next = NULL;
 327                 p->len = pathlen;
 328                 memcpy(p->path, new->name, pathlen);
 329                 p->path[pathlen] = 0;
 330                 p->mode = mode;
 331                 hashclr(p->sha1);
 332                 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
 333                 p->parent[0].status = DIFF_STATUS_MODIFIED;
 334                 p->parent[0].mode = new->ce_mode;
 335                 hashcpy(p->parent[0].sha1, new->sha1);
 336                 p->parent[1].status = DIFF_STATUS_MODIFIED;
 337                 p->parent[1].mode = old->ce_mode;
 338                 hashcpy(p->parent[1].sha1, old->sha1);
 339                 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
 340                 free(p);
 341                 return 0;
 342         }
 343
 344         oldmode = old->ce_mode;
 345         if (mode == oldmode && !hashcmp(sha1, old->sha1) && !dirty_submodule &&
 346             !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
 347                 return 0;
 348
 349         diff_change(&revs->diffopt, oldmode, mode,
 350                     old->sha1, sha1, old->name, 0, dirty_submodule);
 351         return 0;
 352 }
 353
 354 /*
 355  * This gets a mix of an existing index and a tree, one pathname entry
 356  * at a time. The index entry may be a single stage-0 one, but it could
 357  * also be multiple unmerged entries (in which case idx_pos/idx_nr will
 358  * give you the position and number of entries in the index).
 359  */
 360 static void do_oneway_diff(struct unpack_trees_options *o,
 361         struct cache_entry *idx,
 362         struct cache_entry *tree)
 363 {
 364         struct rev_info *revs = o->unpack_data;
 365         int match_missing, cached;
 366
 367         /* if the entry is not checked out, don't examine work tree */
 368         cached = o->index_only ||
 369                 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
 370         /*
 371          * Backward compatibility wart - "diff-index -m" does
 372          * not mean "do not ignore merges", but "match_missing".
 373          *
 374          * But with the revision flag parsing, that's found in
 375          * "!revs->ignore_merges".
 376          */
 377         match_missing = !revs->ignore_merges;
 378
 379         if (cached && idx && ce_stage(idx)) {
 380                 struct diff_filepair *pair;
 381                 pair = diff_unmerge(&revs->diffopt, idx->name);
 382                 if (tree)
 383                         fill_filespec(pair->one, tree->sha1, tree->ce_mode);
 384                 return;
 385         }
 386
 387         /*
 388          * Something added to the tree?
 389          */
 390         if (!tree) {
 391                 show_new_file(revs, idx, cached, match_missing);
 392                 return;
 393         }
 394
 395         /*
 396          * Something removed from the tree?
 397          */
 398         if (!idx) {
 399                 diff_index_show_file(revs, "-", tree, tree->sha1, tree->ce_mode, 0);
 400                 return;
 401         }
 402
 403         /* Show difference between old and new */
 404         show_modified(revs, tree, idx, 1, cached, match_missing);
 405 }
 406
 407 /*
 408  * The unpack_trees() interface is designed for merging, so
 409  * the different source entries are designed primarily for
 410  * the source trees, with the old index being really mainly
 411  * used for being replaced by the result.
 412  *
 413  * For diffing, the index is more important, and we only have a
 414  * single tree.
 415  *
 416  * We're supposed to advance o->pos to skip what we have already processed.
 417  *
 418  * This wrapper makes it all more readable, and takes care of all
 419  * the fairly complex unpack_trees() semantic requirements, including
 420  * the skipping, the path matching, the type conflict cases etc.
 421  */
 422 static int oneway_diff(struct cache_entry **src, struct unpack_trees_options *o)
 423 {
 424         struct cache_entry *idx = src[0];
 425         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)) {
 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 int run_diff_index(struct rev_info *revs, int cached)
 449 {
 450         struct object *ent;
 451         struct tree *tree;
 452         const char *tree_name;
 453         struct unpack_trees_options opts;
 454         struct tree_desc t;
 455
 456         ent = revs->pending.objects[0].item;
 457         tree_name = revs->pending.objects[0].name;
 458         tree = parse_tree_indirect(ent->sha1);
 459         if (!tree)
 460                 return error("bad tree object %s", tree_name);
 461
 462         memset(&opts, 0, sizeof(opts));
 463         opts.head_idx = 1;
 464         opts.index_only = cached;
 465         opts.diff_index_cached = (cached &&
 466                                   !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER));
 467         opts.merge = 1;
 468         opts.fn = oneway_diff;
 469         opts.unpack_data = revs;
 470         opts.src_index = &the_index;
 471         opts.dst_index = NULL;
 472
 473         init_tree_desc(&t, tree->buffer, tree->size);
 474         if (unpack_trees(1, &t, &opts))
 475                 exit(128);
 476
 477         diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
 478         diffcore_fix_diff_index(&revs->diffopt);
 479         diffcore_std(&revs->diffopt);
 480         diff_flush(&revs->diffopt);
 481         return 0;
 482 }
 483
 484 int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
 485 {
 486         struct tree *tree;
 487         struct rev_info revs;
 488         int i;
 489         struct cache_entry **dst;
 490         struct cache_entry *last = NULL;
 491         struct unpack_trees_options opts;
 492         struct tree_desc t;
 493
 494         /*
 495          * This is used by git-blame to run diff-cache internally;
 496          * it potentially needs to repeatedly run this, so we will
 497          * start by removing the higher order entries the last round
 498          * left behind.
 499          */
 500         dst = active_cache;
 501         for (i = 0; i < active_nr; i++) {
 502                 struct cache_entry *ce = active_cache[i];
 503                 if (ce_stage(ce)) {
 504                         if (last && !strcmp(ce->name, last->name))
 505                                 continue;
 506                         cache_tree_invalidate_path(active_cache_tree,
 507                                                    ce->name);
 508                         last = ce;
 509                         ce->ce_flags |= CE_REMOVE;
 510                 }
 511                 *dst++ = ce;
 512         }
 513         active_nr = dst - active_cache;
 514
 515         init_revisions(&revs, NULL);
 516         init_pathspec(&revs.prune_data, opt->pathspec.raw);
 517         tree = parse_tree_indirect(tree_sha1);
 518         if (!tree)
 519                 die("bad tree object %s", sha1_to_hex(tree_sha1));
 520
 521         memset(&opts, 0, sizeof(opts));
 522         opts.head_idx = 1;
 523         opts.index_only = 1;
 524         opts.diff_index_cached = !DIFF_OPT_TST(opt, FIND_COPIES_HARDER);
 525         opts.merge = 1;
 526         opts.fn = oneway_diff;
 527         opts.unpack_data = &revs;
 528         opts.src_index = &the_index;
 529         opts.dst_index = &the_index;
 530
 531         init_tree_desc(&t, tree->buffer, tree->size);
 532         if (unpack_trees(1, &t, &opts))
 533                 exit(128);
 534         return 0;
 535 }
 536
 537 int index_differs_from(const char *def, int diff_flags)
 538 {
 539         struct rev_info rev;
 540         struct setup_revision_opt opt;
 541
 542         init_revisions(&rev, NULL);
 543         memset(&opt, 0, sizeof(opt));
 544         opt.def = def;
 545         setup_revisions(0, NULL, &rev, &opt);
 546         DIFF_OPT_SET(&rev.diffopt, QUICK);
 547         DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
 548         rev.diffopt.flags |= diff_flags;
 549         run_diff_index(&rev, 1);
 550         if (rev.pending.alloc)
 551                 free(rev.pending.objects);
 552         return (DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES) != 0);
 553 }