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         if (option & DIFF_SILENT_ON_REMOVED)
  95                 handle_deprecated_show_diff_q(&revs->diffopt);
  96
  97         diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
  98
  99         if (diff_unmerged_stage < 0)
 100                 diff_unmerged_stage = 2;
 101         entries = active_nr;
 102         for (i = 0; i < entries; i++) {
 103                 struct stat st;
 104                 unsigned int oldmode, newmode;
 105                 struct cache_entry *ce = active_cache[i];
 106                 int changed;
 107                 unsigned dirty_submodule = 0;
 108
 109                 if (diff_can_quit_early(&revs->diffopt))
 110                         break;
 111
 112                 if (!ce_path_match(ce, &revs->prune_data, NULL))
 113                         continue;
 114
 115                 if (ce_stage(ce)) {
 116                         struct combine_diff_path *dpath;
 117                         struct diff_filepair *pair;
 118                         unsigned int wt_mode = 0;
 119                         int num_compare_stages = 0;
 120                         size_t path_len;
 121
 122                         path_len = ce_namelen(ce);
 123
 124                         dpath = xmalloc(combine_diff_path_size(5, path_len));
 125                         dpath->path = (char *) &(dpath->parent[5]);
 126
 127                         dpath->next = NULL;
 128                         memcpy(dpath->path, ce->name, path_len);
 129                         dpath->path[path_len] = '\0';
 130                         hashclr(dpath->sha1);
 131                         memset(&(dpath->parent[0]), 0,
 132                                sizeof(struct combine_diff_parent)*5);
 133
 134                         changed = check_removed(ce, &st);
 135                         if (!changed)
 136                                 wt_mode = ce_mode_from_stat(ce, st.st_mode);
 137                         else {
 138                                 if (changed < 0) {
 139                                         perror(ce->name);
 140                                         continue;
 141                                 }
 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                         diff_addremove(&revs->diffopt, '-', ce->ce_mode,
 208                                        ce->sha1, !is_null_sha1(ce->sha1),
 209                                        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                             !is_null_sha1(ce->sha1), (changed ? 0 : !is_null_sha1(ce->sha1)),
 224                             ce->name, 0, dirty_submodule);
 225
 226         }
 227         diffcore_std(&revs->diffopt);
 228         diff_flush(&revs->diffopt);
 229         return 0;
 230 }
 231
 232 /*
 233  * diff-index
 234  */
 235
 236 /* A file entry went away or appeared */
 237 static void diff_index_show_file(struct rev_info *revs,
 238                                  const char *prefix,
 239                                  const struct cache_entry *ce,
 240                                  const unsigned char *sha1, int sha1_valid,
 241                                  unsigned int mode,
 242                                  unsigned dirty_submodule)
 243 {
 244         diff_addremove(&revs->diffopt, prefix[0], mode,
 245                        sha1, sha1_valid, ce->name, dirty_submodule);
 246 }
 247
 248 static int get_stat_data(const struct cache_entry *ce,
 249                          const unsigned char **sha1p,
 250                          unsigned int *modep,
 251                          int cached, int match_missing,
 252                          unsigned *dirty_submodule, struct diff_options *diffopt)
 253 {
 254         const unsigned char *sha1 = ce->sha1;
 255         unsigned int mode = ce->ce_mode;
 256
 257         if (!cached && !ce_uptodate(ce)) {
 258                 int changed;
 259                 struct stat st;
 260                 changed = check_removed(ce, &st);
 261                 if (changed < 0)
 262                         return -1;
 263                 else if (changed) {
 264                         if (match_missing) {
 265                                 *sha1p = sha1;
 266                                 *modep = mode;
 267                                 return 0;
 268                         }
 269                         return -1;
 270                 }
 271                 changed = match_stat_with_submodule(diffopt, ce, &st,
 272                                                     0, dirty_submodule);
 273                 if (changed) {
 274                         mode = ce_mode_from_stat(ce, st.st_mode);
 275                         sha1 = null_sha1;
 276                 }
 277         }
 278
 279         *sha1p = sha1;
 280         *modep = mode;
 281         return 0;
 282 }
 283
 284 static void show_new_file(struct rev_info *revs,
 285                           const struct cache_entry *new,
 286                           int cached, int match_missing)
 287 {
 288         const unsigned char *sha1;
 289         unsigned int mode;
 290         unsigned dirty_submodule = 0;
 291
 292         /*
 293          * New file in the index: it might actually be different in
 294          * the working tree.
 295          */
 296         if (get_stat_data(new, &sha1, &mode, cached, match_missing,
 297             &dirty_submodule, &revs->diffopt) < 0)
 298                 return;
 299
 300         diff_index_show_file(revs, "+", new, sha1, !is_null_sha1(sha1), mode, dirty_submodule);
 301 }
 302
 303 static int show_modified(struct rev_info *revs,
 304                          const struct cache_entry *old,
 305                          const struct cache_entry *new,
 306                          int report_missing,
 307                          int cached, int match_missing)
 308 {
 309         unsigned int mode, oldmode;
 310         const unsigned char *sha1;
 311         unsigned dirty_submodule = 0;
 312
 313         if (get_stat_data(new, &sha1, &mode, cached, match_missing,
 314                           &dirty_submodule, &revs->diffopt) < 0) {
 315                 if (report_missing)
 316                         diff_index_show_file(revs, "-", old,
 317                                              old->sha1, 1, old->ce_mode, 0);
 318                 return -1;
 319         }
 320
 321         if (revs->combine_merges && !cached &&
 322             (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
 323                 struct combine_diff_path *p;
 324                 int pathlen = ce_namelen(new);
 325
 326                 p = xmalloc(combine_diff_path_size(2, pathlen));
 327                 p->path = (char *) &p->parent[2];
 328                 p->next = NULL;
 329                 memcpy(p->path, new->name, pathlen);
 330                 p->path[pathlen] = 0;
 331                 p->mode = mode;
 332                 hashclr(p->sha1);
 333                 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
 334                 p->parent[0].status = DIFF_STATUS_MODIFIED;
 335                 p->parent[0].mode = new->ce_mode;
 336                 hashcpy(p->parent[0].sha1, new->sha1);
 337                 p->parent[1].status = DIFF_STATUS_MODIFIED;
 338                 p->parent[1].mode = old->ce_mode;
 339                 hashcpy(p->parent[1].sha1, old->sha1);
 340                 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
 341                 free(p);
 342                 return 0;
 343         }
 344
 345         oldmode = old->ce_mode;
 346         if (mode == oldmode && !hashcmp(sha1, old->sha1) && !dirty_submodule &&
 347             !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER))
 348                 return 0;
 349
 350         diff_change(&revs->diffopt, oldmode, mode,
 351                     old->sha1, sha1, 1, !is_null_sha1(sha1),
 352                     old->name, 0, dirty_submodule);
 353         return 0;
 354 }
 355
 356 /*
 357  * This gets a mix of an existing index and a tree, one pathname entry
 358  * at a time. The index entry may be a single stage-0 one, but it could
 359  * also be multiple unmerged entries (in which case idx_pos/idx_nr will
 360  * give you the position and number of entries in the index).
 361  */
 362 static void do_oneway_diff(struct unpack_trees_options *o,
 363                            const struct cache_entry *idx,
 364                            const struct cache_entry *tree)
 365 {
 366         struct rev_info *revs = o->unpack_data;
 367         int match_missing, cached;
 368
 369         /* if the entry is not checked out, don't examine work tree */
 370         cached = o->index_only ||
 371                 (idx && ((idx->ce_flags & CE_VALID) || ce_skip_worktree(idx)));
 372         /*
 373          * Backward compatibility wart - "diff-index -m" does
 374          * not mean "do not ignore merges", but "match_missing".
 375          *
 376          * But with the revision flag parsing, that's found in
 377          * "!revs->ignore_merges".
 378          */
 379         match_missing = !revs->ignore_merges;
 380
 381         if (cached && idx && ce_stage(idx)) {
 382                 struct diff_filepair *pair;
 383                 pair = diff_unmerge(&revs->diffopt, idx->name);
 384                 if (tree)
 385                         fill_filespec(pair->one, tree->sha1, 1, tree->ce_mode);
 386                 return;
 387         }
 388
 389         /*
 390          * Something added to the tree?
 391          */
 392         if (!tree) {
 393                 show_new_file(revs, idx, cached, match_missing);
 394                 return;
 395         }
 396
 397         /*
 398          * Something removed from the tree?
 399          */
 400         if (!idx) {
 401                 diff_index_show_file(revs, "-", tree, tree->sha1, 1, tree->ce_mode, 0);
 402                 return;
 403         }
 404
 405         /* Show difference between old and new */
 406         show_modified(revs, tree, idx, 1, cached, match_missing);
 407 }
 408
 409 /*
 410  * The unpack_trees() interface is designed for merging, so
 411  * the different source entries are designed primarily for
 412  * the source trees, with the old index being really mainly
 413  * used for being replaced by the result.
 414  *
 415  * For diffing, the index is more important, and we only have a
 416  * single tree.
 417  *
 418  * We're supposed to advance o->pos to skip what we have already processed.
 419  *
 420  * This wrapper makes it all more readable, and takes care of all
 421  * the fairly complex unpack_trees() semantic requirements, including
 422  * the skipping, the path matching, the type conflict cases etc.
 423  */
 424 static int oneway_diff(const struct cache_entry * const *src,
 425                        struct unpack_trees_options *o)
 426 {
 427         const struct cache_entry *idx = src[0];
 428         const struct cache_entry *tree = src[1];
 429         struct rev_info *revs = o->unpack_data;
 430
 431         /*
 432          * Unpack-trees generates a DF/conflict entry if
 433          * there was a directory in the index and a tree
 434          * in the tree. From a diff standpoint, that's a
 435          * delete of the tree and a create of the file.
 436          */
 437         if (tree == o->df_conflict_entry)
 438                 tree = NULL;
 439
 440         if (ce_path_match(idx ? idx : tree, &revs->prune_data, NULL)) {
 441                 do_oneway_diff(o, idx, tree);
 442                 if (diff_can_quit_early(&revs->diffopt)) {
 443                         o->exiting_early = 1;
 444                         return -1;
 445                 }
 446         }
 447
 448         return 0;
 449 }
 450
 451 static int diff_cache(struct rev_info *revs,
 452                       const unsigned char *tree_sha1,
 453                       const char *tree_name,
 454                       int cached)
 455 {
 456         struct tree *tree;
 457         struct tree_desc t;
 458         struct unpack_trees_options opts;
 459
 460         tree = parse_tree_indirect(tree_sha1);
 461         if (!tree)
 462                 return error("bad tree object %s",
 463                              tree_name ? tree_name : sha1_to_hex(tree_sha1));
 464         memset(&opts, 0, sizeof(opts));
 465         opts.head_idx = 1;
 466         opts.index_only = cached;
 467         opts.diff_index_cached = (cached &&
 468                                   !DIFF_OPT_TST(&revs->diffopt, FIND_COPIES_HARDER));
 469         opts.merge = 1;
 470         opts.fn = oneway_diff;
 471         opts.unpack_data = revs;
 472         opts.src_index = &the_index;
 473         opts.dst_index = NULL;
 474         opts.pathspec = &revs->diffopt.pathspec;
 475         opts.pathspec->recursive = 1;
 476
 477         init_tree_desc(&t, tree->buffer, tree->size);
 478         return unpack_trees(1, &t, &opts);
 479 }
 480
 481 int run_diff_index(struct rev_info *revs, int cached)
 482 {
 483         struct object_array_entry *ent;
 484
 485         ent = revs->pending.objects;
 486         if (diff_cache(revs, ent->item->sha1, ent->name, cached))
 487                 exit(128);
 488
 489         diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
 490         diffcore_fix_diff_index(&revs->diffopt);
 491         diffcore_std(&revs->diffopt);
 492         diff_flush(&revs->diffopt);
 493         return 0;
 494 }
 495
 496 int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
 497 {
 498         struct rev_info revs;
 499
 500         init_revisions(&revs, NULL);
 501         copy_pathspec(&revs.prune_data, &opt->pathspec);
 502         revs.diffopt = *opt;
 503
 504         if (diff_cache(&revs, tree_sha1, NULL, 1))
 505                 exit(128);
 506         return 0;
 507 }
 508
 509 int index_differs_from(const char *def, int diff_flags)
 510 {
 511         struct rev_info rev;
 512         struct setup_revision_opt opt;
 513
 514         init_revisions(&rev, NULL);
 515         memset(&opt, 0, sizeof(opt));
 516         opt.def = def;
 517         setup_revisions(0, NULL, &rev, &opt);
 518         DIFF_OPT_SET(&rev.diffopt, QUICK);
 519         DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
 520         rev.diffopt.flags |= diff_flags;
 521         run_diff_index(&rev, 1);
 522         if (rev.pending.alloc)
 523                 free(rev.pending.objects);
 524         return (DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES) != 0);
 525 }