git.oblomov.eu Git - git/blob - builtin/diff.c

   1 /*
   2  * Builtin "git diff"
   3  *
   4  * Copyright (c) 2006 Junio C Hamano
   5  */
   6 #define USE_THE_INDEX_COMPATIBILITY_MACROS
   7 #include "cache.h"
   8 #include "config.h"
   9 #include "ewah/ewok.h"
  10 #include "lockfile.h"
  11 #include "color.h"
  12 #include "commit.h"
  13 #include "blob.h"
  14 #include "tag.h"
  15 #include "diff.h"
  16 #include "diffcore.h"
  17 #include "revision.h"
  18 #include "log-tree.h"
  19 #include "builtin.h"
  20 #include "submodule.h"
  21 #include "sha1-array.h"
  22
  23 #define DIFF_NO_INDEX_EXPLICIT 1
  24 #define DIFF_NO_INDEX_IMPLICIT 2
  25
  26 static const char builtin_diff_usage[] =
  27 "git diff [<options>] [<commit> [<commit>]] [--] [<path>...]";
  28
  29 static const char *blob_path(struct object_array_entry *entry)
  30 {
  31         return entry->path ? entry->path : entry->name;
  32 }
  33
  34 static void stuff_change(struct diff_options *opt,
  35                          unsigned old_mode, unsigned new_mode,
  36                          const struct object_id *old_oid,
  37                          const struct object_id *new_oid,
  38                          int old_oid_valid,
  39                          int new_oid_valid,
  40                          const char *old_path,
  41                          const char *new_path)
  42 {
  43         struct diff_filespec *one, *two;
  44
  45         if (!is_null_oid(old_oid) && !is_null_oid(new_oid) &&
  46             oideq(old_oid, new_oid) && (old_mode == new_mode))
  47                 return;
  48
  49         if (opt->flags.reverse_diff) {
  50                 SWAP(old_mode, new_mode);
  51                 SWAP(old_oid, new_oid);
  52                 SWAP(old_path, new_path);
  53         }
  54
  55         if (opt->prefix &&
  56             (strncmp(old_path, opt->prefix, opt->prefix_length) ||
  57              strncmp(new_path, opt->prefix, opt->prefix_length)))
  58                 return;
  59
  60         one = alloc_filespec(old_path);
  61         two = alloc_filespec(new_path);
  62         fill_filespec(one, old_oid, old_oid_valid, old_mode);
  63         fill_filespec(two, new_oid, new_oid_valid, new_mode);
  64
  65         diff_queue(&diff_queued_diff, one, two);
  66 }
  67
  68 static int builtin_diff_b_f(struct rev_info *revs,
  69                             int argc, const char **argv,
  70                             struct object_array_entry **blob)
  71 {
  72         /* Blob vs file in the working tree*/
  73         struct stat st;
  74         const char *path;
  75
  76         if (argc > 1)
  77                 usage(builtin_diff_usage);
  78
  79         GUARD_PATHSPEC(&revs->prune_data, PATHSPEC_FROMTOP | PATHSPEC_LITERAL);
  80         path = revs->prune_data.items[0].match;
  81
  82         if (lstat(path, &st))
  83                 die_errno(_("failed to stat '%s'"), path);
  84         if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
  85                 die(_("'%s': not a regular file or symlink"), path);
  86
  87         diff_set_mnemonic_prefix(&revs->diffopt, "o/", "w/");
  88
  89         if (blob[0]->mode == S_IFINVALID)
  90                 blob[0]->mode = canon_mode(st.st_mode);
  91
  92         stuff_change(&revs->diffopt,
  93                      blob[0]->mode, canon_mode(st.st_mode),
  94                      &blob[0]->item->oid, &null_oid,
  95                      1, 0,
  96                      blob[0]->path ? blob[0]->path : path,
  97                      path);
  98         diffcore_std(&revs->diffopt);
  99         diff_flush(&revs->diffopt);
 100         return 0;
 101 }
 102
 103 static int builtin_diff_blobs(struct rev_info *revs,
 104                               int argc, const char **argv,
 105                               struct object_array_entry **blob)
 106 {
 107         const unsigned mode = canon_mode(S_IFREG | 0644);
 108
 109         if (argc > 1)
 110                 usage(builtin_diff_usage);
 111
 112         if (blob[0]->mode == S_IFINVALID)
 113                 blob[0]->mode = mode;
 114
 115         if (blob[1]->mode == S_IFINVALID)
 116                 blob[1]->mode = mode;
 117
 118         stuff_change(&revs->diffopt,
 119                      blob[0]->mode, blob[1]->mode,
 120                      &blob[0]->item->oid, &blob[1]->item->oid,
 121                      1, 1,
 122                      blob_path(blob[0]), blob_path(blob[1]));
 123         diffcore_std(&revs->diffopt);
 124         diff_flush(&revs->diffopt);
 125         return 0;
 126 }
 127
 128 static int builtin_diff_index(struct rev_info *revs,
 129                               int argc, const char **argv)
 130 {
 131         int cached = 0;
 132         while (1 < argc) {
 133                 const char *arg = argv[1];
 134                 if (!strcmp(arg, "--cached") || !strcmp(arg, "--staged"))
 135                         cached = 1;
 136                 else
 137                         usage(builtin_diff_usage);
 138                 argv++; argc--;
 139         }
 140         /*
 141          * Make sure there is one revision (i.e. pending object),
 142          * and there is no revision filtering parameters.
 143          */
 144         if (revs->pending.nr != 1 ||
 145             revs->max_count != -1 || revs->min_age != -1 ||
 146             revs->max_age != -1)
 147                 usage(builtin_diff_usage);
 148         if (!cached) {
 149                 setup_work_tree();
 150                 if (read_cache_preload(&revs->diffopt.pathspec) < 0) {
 151                         perror("read_cache_preload");
 152                         return -1;
 153                 }
 154         } else if (read_cache() < 0) {
 155                 perror("read_cache");
 156                 return -1;
 157         }
 158         return run_diff_index(revs, cached);
 159 }
 160
 161 static int builtin_diff_tree(struct rev_info *revs,
 162                              int argc, const char **argv,
 163                              struct object_array_entry *ent0,
 164                              struct object_array_entry *ent1)
 165 {
 166         const struct object_id *(oid[2]);
 167         int swap = 0;
 168
 169         if (argc > 1)
 170                 usage(builtin_diff_usage);
 171
 172         /*
 173          * We saw two trees, ent0 and ent1.  If ent1 is uninteresting,
 174          * swap them.
 175          */
 176         if (ent1->item->flags & UNINTERESTING)
 177                 swap = 1;
 178         oid[swap] = &ent0->item->oid;
 179         oid[1 - swap] = &ent1->item->oid;
 180         diff_tree_oid(oid[0], oid[1], "", &revs->diffopt);
 181         log_tree_diff_flush(revs);
 182         return 0;
 183 }
 184
 185 static int builtin_diff_combined(struct rev_info *revs,
 186                                  int argc, const char **argv,
 187                                  struct object_array_entry *ent,
 188                                  int ents)
 189 {
 190         struct oid_array parents = OID_ARRAY_INIT;
 191         int i;
 192
 193         if (argc > 1)
 194                 usage(builtin_diff_usage);
 195
 196         if (!revs->dense_combined_merges && !revs->combine_merges)
 197                 revs->dense_combined_merges = revs->combine_merges = 1;
 198         for (i = 1; i < ents; i++)
 199                 oid_array_append(&parents, &ent[i].item->oid);
 200         diff_tree_combined(&ent[0].item->oid, &parents,
 201                            revs->dense_combined_merges, revs);
 202         oid_array_clear(&parents);
 203         return 0;
 204 }
 205
 206 static void refresh_index_quietly(void)
 207 {
 208         struct lock_file lock_file = LOCK_INIT;
 209         int fd;
 210
 211         fd = hold_locked_index(&lock_file, 0);
 212         if (fd < 0)
 213                 return;
 214         discard_cache();
 215         read_cache();
 216         refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
 217         repo_update_index_if_able(the_repository, &lock_file);
 218 }
 219
 220 static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv)
 221 {
 222         unsigned int options = 0;
 223
 224         while (1 < argc && argv[1][0] == '-') {
 225                 if (!strcmp(argv[1], "--base"))
 226                         revs->max_count = 1;
 227                 else if (!strcmp(argv[1], "--ours"))
 228                         revs->max_count = 2;
 229                 else if (!strcmp(argv[1], "--theirs"))
 230                         revs->max_count = 3;
 231                 else if (!strcmp(argv[1], "-q"))
 232                         options |= DIFF_SILENT_ON_REMOVED;
 233                 else if (!strcmp(argv[1], "-h"))
 234                         usage(builtin_diff_usage);
 235                 else
 236                         return error(_("invalid option: %s"), argv[1]);
 237                 argv++; argc--;
 238         }
 239
 240         /*
 241          * "diff --base" should not combine merges because it was not
 242          * asked to.  "diff -c" should not densify (if the user wants
 243          * dense one, --cc can be explicitly asked for, or just rely
 244          * on the default).
 245          */
 246         if (revs->max_count == -1 && !revs->combine_merges &&
 247             (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
 248                 revs->combine_merges = revs->dense_combined_merges = 1;
 249
 250         setup_work_tree();
 251         if (read_cache_preload(&revs->diffopt.pathspec) < 0) {
 252                 perror("read_cache_preload");
 253                 return -1;
 254         }
 255         return run_diff_files(revs, options);
 256 }
 257
 258 struct symdiff {
 259         struct bitmap *skip;
 260         int warn;
 261         const char *base, *left, *right;
 262 };
 263
 264 /*
 265  * Check for symmetric-difference arguments, and if present, arrange
 266  * everything we need to know to handle them correctly.  As a bonus,
 267  * weed out all bogus range-based revision specifications, e.g.,
 268  * "git diff A..B C..D" or "git diff A..B C" get rejected.
 269  *
 270  * For an actual symmetric diff, *symdiff is set this way:
 271  *
 272  *  - its skip is non-NULL and marks *all* rev->pending.objects[i]
 273  *    indices that the caller should ignore (extra merge bases, of
 274  *    which there might be many, and A in A...B).  Note that the
 275  *    chosen merge base and right side are NOT marked.
 276  *  - warn is set if there are multiple merge bases.
 277  *  - base, left, and right point to the names to use in a
 278  *    warning about multiple merge bases.
 279  *
 280  * If there is no symmetric diff argument, sym->skip is NULL and
 281  * sym->warn is cleared.  The remaining fields are not set.
 282  */
 283 static void symdiff_prepare(struct rev_info *rev, struct symdiff *sym)
 284 {
 285         int i, is_symdiff = 0, basecount = 0, othercount = 0;
 286         int lpos = -1, rpos = -1, basepos = -1;
 287         struct bitmap *map = NULL;
 288
 289         /*
 290          * Use the whence fields to find merge bases and left and
 291          * right parts of symmetric difference, so that we do not
 292          * depend on the order that revisions are parsed.  If there
 293          * are any revs that aren't from these sources, we have a
 294          * "git diff C A...B" or "git diff A...B C" case.  Or we
 295          * could even get "git diff A...B C...E", for instance.
 296          *
 297          * If we don't have just one merge base, we pick one
 298          * at random.
 299          *
 300          * NB: REV_CMD_LEFT, REV_CMD_RIGHT are also used for A..B,
 301          * so we must check for SYMMETRIC_LEFT too.  The two arrays
 302          * rev->pending.objects and rev->cmdline.rev are parallel.
 303          */
 304         for (i = 0; i < rev->cmdline.nr; i++) {
 305                 struct object *obj = rev->pending.objects[i].item;
 306                 switch (rev->cmdline.rev[i].whence) {
 307                 case REV_CMD_MERGE_BASE:
 308                         if (basepos < 0)
 309                                 basepos = i;
 310                         basecount++;
 311                         break;          /* do mark all bases */
 312                 case REV_CMD_LEFT:
 313                         if (lpos >= 0)
 314                                 usage(builtin_diff_usage);
 315                         lpos = i;
 316                         if (obj->flags & SYMMETRIC_LEFT) {
 317                                 is_symdiff = 1;
 318                                 break;  /* do mark A */
 319                         }
 320                         continue;
 321                 case REV_CMD_RIGHT:
 322                         if (rpos >= 0)
 323                                 usage(builtin_diff_usage);
 324                         rpos = i;
 325                         continue;       /* don't mark B */
 326                 case REV_CMD_PARENTS_ONLY:
 327                 case REV_CMD_REF:
 328                 case REV_CMD_REV:
 329                         othercount++;
 330                         continue;
 331                 }
 332                 if (map == NULL)
 333                         map = bitmap_new();
 334                 bitmap_set(map, i);
 335         }
 336
 337         /*
 338          * Forbid any additional revs for both A...B and A..B.
 339          */
 340         if (lpos >= 0 && othercount > 0)
 341                 usage(builtin_diff_usage);
 342
 343         if (!is_symdiff) {
 344                 bitmap_free(map);
 345                 sym->warn = 0;
 346                 sym->skip = NULL;
 347                 return;
 348         }
 349
 350         sym->left = rev->pending.objects[lpos].name;
 351         sym->right = rev->pending.objects[rpos].name;
 352         sym->base = rev->pending.objects[basepos].name;
 353         if (basecount == 0)
 354                 die(_("%s...%s: no merge base"), sym->left, sym->right);
 355         bitmap_unset(map, basepos);     /* unmark the base we want */
 356         sym->warn = basecount > 1;
 357         sym->skip = map;
 358 }
 359
 360 int cmd_diff(int argc, const char **argv, const char *prefix)
 361 {
 362         int i;
 363         struct rev_info rev;
 364         struct object_array ent = OBJECT_ARRAY_INIT;
 365         int blobs = 0, paths = 0;
 366         struct object_array_entry *blob[2];
 367         int nongit = 0, no_index = 0;
 368         int result = 0;
 369         struct symdiff sdiff;
 370
 371         /*
 372          * We could get N tree-ish in the rev.pending_objects list.
 373          * Also there could be M blobs there, and P pathspecs.
 374          *
 375          * N=0, M=0:
 376          *      cache vs files (diff-files)
 377          * N=0, M=2:
 378          *      compare two random blobs.  P must be zero.
 379          * N=0, M=1, P=1:
 380          *      compare a blob with a working tree file.
 381          *
 382          * N=1, M=0:
 383          *      tree vs cache (diff-index --cached)
 384          *
 385          * N=2, M=0:
 386          *      tree vs tree (diff-tree)
 387          *
 388          * N=0, M=0, P=2:
 389          *      compare two filesystem entities (aka --no-index).
 390          *
 391          * Other cases are errors.
 392          */
 393
 394         /* Were we asked to do --no-index explicitly? */
 395         for (i = 1; i < argc; i++) {
 396                 if (!strcmp(argv[i], "--")) {
 397                         i++;
 398                         break;
 399                 }
 400                 if (!strcmp(argv[i], "--no-index"))
 401                         no_index = DIFF_NO_INDEX_EXPLICIT;
 402                 if (argv[i][0] != '-')
 403                         break;
 404         }
 405
 406         prefix = setup_git_directory_gently(&nongit);
 407
 408         if (!no_index) {
 409                 /*
 410                  * Treat git diff with at least one path outside of the
 411                  * repo the same as if the command would have been executed
 412                  * outside of a git repository.  In this case it behaves
 413                  * the same way as "git diff --no-index <a> <b>", which acts
 414                  * as a colourful "diff" replacement.
 415                  */
 416                 if (nongit || ((argc == i + 2) &&
 417                                (!path_inside_repo(prefix, argv[i]) ||
 418                                 !path_inside_repo(prefix, argv[i + 1]))))
 419                         no_index = DIFF_NO_INDEX_IMPLICIT;
 420         }
 421
 422         init_diff_ui_defaults();
 423         git_config(git_diff_ui_config, NULL);
 424         precompose_argv(argc, argv);
 425
 426         repo_init_revisions(the_repository, &rev, prefix);
 427
 428         /* Set up defaults that will apply to both no-index and regular diffs. */
 429         rev.diffopt.stat_width = -1;
 430         rev.diffopt.stat_graph_width = -1;
 431         rev.diffopt.flags.allow_external = 1;
 432         rev.diffopt.flags.allow_textconv = 1;
 433
 434         /* If this is a no-index diff, just run it and exit there. */
 435         if (no_index)
 436                 exit(diff_no_index(&rev, no_index == DIFF_NO_INDEX_IMPLICIT,
 437                                    argc, argv));
 438
 439
 440         /*
 441          * Otherwise, we are doing the usual "git" diff; set up any
 442          * further defaults that apply to regular diffs.
 443          */
 444         rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
 445
 446         /*
 447          * Default to intent-to-add entries invisible in the
 448          * index. This makes them show up as new files in diff-files
 449          * and not at all in diff-cached.
 450          */
 451         rev.diffopt.ita_invisible_in_index = 1;
 452
 453         if (nongit)
 454                 die(_("Not a git repository"));
 455         argc = setup_revisions(argc, argv, &rev, NULL);
 456         if (!rev.diffopt.output_format) {
 457                 rev.diffopt.output_format = DIFF_FORMAT_PATCH;
 458                 diff_setup_done(&rev.diffopt);
 459         }
 460
 461         rev.diffopt.flags.recursive = 1;
 462
 463         setup_diff_pager(&rev.diffopt);
 464
 465         /*
 466          * Do we have --cached and not have a pending object, then
 467          * default to HEAD by hand.  Eek.
 468          */
 469         if (!rev.pending.nr) {
 470                 int i;
 471                 for (i = 1; i < argc; i++) {
 472                         const char *arg = argv[i];
 473                         if (!strcmp(arg, "--"))
 474                                 break;
 475                         else if (!strcmp(arg, "--cached") ||
 476                                  !strcmp(arg, "--staged")) {
 477                                 add_head_to_pending(&rev);
 478                                 if (!rev.pending.nr) {
 479                                         struct tree *tree;
 480                                         tree = lookup_tree(the_repository,
 481                                                            the_repository->hash_algo->empty_tree);
 482                                         add_pending_object(&rev, &tree->object, "HEAD");
 483                                 }
 484                                 break;
 485                         }
 486                 }
 487         }
 488
 489         symdiff_prepare(&rev, &sdiff);
 490         for (i = 0; i < rev.pending.nr; i++) {
 491                 struct object_array_entry *entry = &rev.pending.objects[i];
 492                 struct object *obj = entry->item;
 493                 const char *name = entry->name;
 494                 int flags = (obj->flags & UNINTERESTING);
 495                 if (!obj->parsed)
 496                         obj = parse_object(the_repository, &obj->oid);
 497                 obj = deref_tag(the_repository, obj, NULL, 0);
 498                 if (!obj)
 499                         die(_("invalid object '%s' given."), name);
 500                 if (obj->type == OBJ_COMMIT)
 501                         obj = &get_commit_tree(((struct commit *)obj))->object;
 502
 503                 if (obj->type == OBJ_TREE) {
 504                         if (sdiff.skip && bitmap_get(sdiff.skip, i))
 505                                 continue;
 506                         obj->flags |= flags;
 507                         add_object_array(obj, name, &ent);
 508                 } else if (obj->type == OBJ_BLOB) {
 509                         if (2 <= blobs)
 510                                 die(_("more than two blobs given: '%s'"), name);
 511                         blob[blobs] = entry;
 512                         blobs++;
 513
 514                 } else {
 515                         die(_("unhandled object '%s' given."), name);
 516                 }
 517         }
 518         if (rev.prune_data.nr)
 519                 paths += rev.prune_data.nr;
 520
 521         /*
 522          * Now, do the arguments look reasonable?
 523          */
 524         if (!ent.nr) {
 525                 switch (blobs) {
 526                 case 0:
 527                         result = builtin_diff_files(&rev, argc, argv);
 528                         break;
 529                 case 1:
 530                         if (paths != 1)
 531                                 usage(builtin_diff_usage);
 532                         result = builtin_diff_b_f(&rev, argc, argv, blob);
 533                         break;
 534                 case 2:
 535                         if (paths)
 536                                 usage(builtin_diff_usage);
 537                         result = builtin_diff_blobs(&rev, argc, argv, blob);
 538                         break;
 539                 default:
 540                         usage(builtin_diff_usage);
 541                 }
 542         }
 543         else if (blobs)
 544                 usage(builtin_diff_usage);
 545         else if (ent.nr == 1)
 546                 result = builtin_diff_index(&rev, argc, argv);
 547         else if (ent.nr == 2) {
 548                 if (sdiff.warn)
 549                         warning(_("%s...%s: multiple merge bases, using %s"),
 550                                 sdiff.left, sdiff.right, sdiff.base);
 551                 result = builtin_diff_tree(&rev, argc, argv,
 552                                            &ent.objects[0], &ent.objects[1]);
 553         } else
 554                 result = builtin_diff_combined(&rev, argc, argv,
 555                                                ent.objects, ent.nr);
 556         result = diff_result_code(&rev.diffopt, result);
 557         if (1 < rev.diffopt.skip_stat_unmatch)
 558                 refresh_index_quietly();
 559         UNLEAK(rev);
 560         UNLEAK(ent);
 561         UNLEAK(blob);
 562         return result;
 563 }