builtin/diff.c

   1 /*
   2  * Builtin "git diff"
   3  *
   4  * Copyright (c) 2006 Junio C Hamano
   5  */
   6 #include "cache.h"
   7 #include "lockfile.h"
   8 #include "color.h"
   9 #include "commit.h"
  10 #include "blob.h"
  11 #include "tag.h"
  12 #include "diff.h"
  13 #include "diffcore.h"
  14 #include "revision.h"
  15 #include "log-tree.h"
  16 #include "builtin.h"
  17 #include "submodule.h"
  18 #include "sha1-array.h"
  19
  20 #define DIFF_NO_INDEX_EXPLICIT 1
  21 #define DIFF_NO_INDEX_IMPLICIT 2
  22
  23 static const char builtin_diff_usage[] =
  24 "git diff [<options>] [<commit> [<commit>]] [--] [<path>...]";
  25
  26 static void stuff_change(struct diff_options *opt,
  27                          unsigned old_mode, unsigned new_mode,
  28                          const struct object_id *old_oid,
  29                          const struct object_id *new_oid,
  30                          int old_oid_valid,
  31                          int new_oid_valid,
  32                          const char *old_path,
  33                          const char *new_path)
  34 {
  35         struct diff_filespec *one, *two;
  36
  37         if (!is_null_oid(old_oid) && !is_null_oid(new_oid) &&
  38             !oidcmp(old_oid, new_oid) && (old_mode == new_mode))
  39                 return;
  40
  41         if (DIFF_OPT_TST(opt, REVERSE_DIFF)) {
  42                 SWAP(old_mode, new_mode);
  43                 SWAP(old_oid, new_oid);
  44                 SWAP(old_path, new_path);
  45         }
  46
  47         if (opt->prefix &&
  48             (strncmp(old_path, opt->prefix, opt->prefix_length) ||
  49              strncmp(new_path, opt->prefix, opt->prefix_length)))
  50                 return;
  51
  52         one = alloc_filespec(old_path);
  53         two = alloc_filespec(new_path);
  54         fill_filespec(one, old_oid->hash, old_oid_valid, old_mode);
  55         fill_filespec(two, new_oid->hash, new_oid_valid, new_mode);
  56
  57         diff_queue(&diff_queued_diff, one, two);
  58 }
  59
  60 static int builtin_diff_b_f(struct rev_info *revs,
  61                             int argc, const char **argv,
  62                             struct object_array_entry **blob)
  63 {
  64         /* Blob vs file in the working tree*/
  65         struct stat st;
  66         const char *path;
  67
  68         if (argc > 1)
  69                 usage(builtin_diff_usage);
  70
  71         GUARD_PATHSPEC(&revs->prune_data, PATHSPEC_FROMTOP | PATHSPEC_LITERAL);
  72         path = revs->prune_data.items[0].match;
  73
  74         if (lstat(path, &st))
  75                 die_errno(_("failed to stat '%s'"), path);
  76         if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
  77                 die(_("'%s': not a regular file or symlink"), path);
  78
  79         diff_set_mnemonic_prefix(&revs->diffopt, "o/", "w/");
  80
  81         if (blob[0]->mode == S_IFINVALID)
  82                 blob[0]->mode = canon_mode(st.st_mode);
  83
  84         stuff_change(&revs->diffopt,
  85                      blob[0]->mode, canon_mode(st.st_mode),
  86                      &blob[0]->item->oid, &null_oid,
  87                      1, 0,
  88                      path, path);
  89         diffcore_std(&revs->diffopt);
  90         diff_flush(&revs->diffopt);
  91         return 0;
  92 }
  93
  94 static int builtin_diff_blobs(struct rev_info *revs,
  95                               int argc, const char **argv,
  96                               struct object_array_entry **blob)
  97 {
  98         unsigned mode = canon_mode(S_IFREG | 0644);
  99
 100         if (argc > 1)
 101                 usage(builtin_diff_usage);
 102
 103         if (blob[0]->mode == S_IFINVALID)
 104                 blob[0]->mode = mode;
 105
 106         if (blob[1]->mode == S_IFINVALID)
 107                 blob[1]->mode = mode;
 108
 109         stuff_change(&revs->diffopt,
 110                      blob[0]->mode, blob[1]->mode,
 111                      &blob[0]->item->oid, &blob[1]->item->oid,
 112                      1, 1,
 113                      blob[0]->name, blob[1]->name);
 114         diffcore_std(&revs->diffopt);
 115         diff_flush(&revs->diffopt);
 116         return 0;
 117 }
 118
 119 static int builtin_diff_index(struct rev_info *revs,
 120                               int argc, const char **argv)
 121 {
 122         int cached = 0;
 123         while (1 < argc) {
 124                 const char *arg = argv[1];
 125                 if (!strcmp(arg, "--cached") || !strcmp(arg, "--staged"))
 126                         cached = 1;
 127                 else
 128                         usage(builtin_diff_usage);
 129                 argv++; argc--;
 130         }
 131         /*
 132          * Make sure there is one revision (i.e. pending object),
 133          * and there is no revision filtering parameters.
 134          */
 135         if (revs->pending.nr != 1 ||
 136             revs->max_count != -1 || revs->min_age != -1 ||
 137             revs->max_age != -1)
 138                 usage(builtin_diff_usage);
 139         if (!cached) {
 140                 setup_work_tree();
 141                 if (read_cache_preload(&revs->diffopt.pathspec) < 0) {
 142                         perror("read_cache_preload");
 143                         return -1;
 144                 }
 145         } else if (read_cache() < 0) {
 146                 perror("read_cache");
 147                 return -1;
 148         }
 149         return run_diff_index(revs, cached);
 150 }
 151
 152 static int builtin_diff_tree(struct rev_info *revs,
 153                              int argc, const char **argv,
 154                              struct object_array_entry *ent0,
 155                              struct object_array_entry *ent1)
 156 {
 157         const struct object_id *(oid[2]);
 158         int swap = 0;
 159
 160         if (argc > 1)
 161                 usage(builtin_diff_usage);
 162
 163         /*
 164          * We saw two trees, ent0 and ent1.  If ent1 is uninteresting,
 165          * swap them.
 166          */
 167         if (ent1->item->flags & UNINTERESTING)
 168                 swap = 1;
 169         oid[swap] = &ent0->item->oid;
 170         oid[1 - swap] = &ent1->item->oid;
 171         diff_tree_sha1(oid[0]->hash, oid[1]->hash, "", &revs->diffopt);
 172         log_tree_diff_flush(revs);
 173         return 0;
 174 }
 175
 176 static int builtin_diff_combined(struct rev_info *revs,
 177                                  int argc, const char **argv,
 178                                  struct object_array_entry *ent,
 179                                  int ents)
 180 {
 181         struct oid_array parents = OID_ARRAY_INIT;
 182         int i;
 183
 184         if (argc > 1)
 185                 usage(builtin_diff_usage);
 186
 187         if (!revs->dense_combined_merges && !revs->combine_merges)
 188                 revs->dense_combined_merges = revs->combine_merges = 1;
 189         for (i = 1; i < ents; i++)
 190                 oid_array_append(&parents, &ent[i].item->oid);
 191         diff_tree_combined(ent[0].item->oid.hash, &parents,
 192                            revs->dense_combined_merges, revs);
 193         oid_array_clear(&parents);
 194         return 0;
 195 }
 196
 197 static void refresh_index_quietly(void)
 198 {
 199         struct lock_file *lock_file;
 200         int fd;
 201
 202         lock_file = xcalloc(1, sizeof(struct lock_file));
 203         fd = hold_locked_index(lock_file, 0);
 204         if (fd < 0)
 205                 return;
 206         discard_cache();
 207         read_cache();
 208         refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
 209         update_index_if_able(&the_index, lock_file);
 210 }
 211
 212 static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv)
 213 {
 214         unsigned int options = 0;
 215
 216         while (1 < argc && argv[1][0] == '-') {
 217                 if (!strcmp(argv[1], "--base"))
 218                         revs->max_count = 1;
 219                 else if (!strcmp(argv[1], "--ours"))
 220                         revs->max_count = 2;
 221                 else if (!strcmp(argv[1], "--theirs"))
 222                         revs->max_count = 3;
 223                 else if (!strcmp(argv[1], "-q"))
 224                         options |= DIFF_SILENT_ON_REMOVED;
 225                 else if (!strcmp(argv[1], "-h"))
 226                         usage(builtin_diff_usage);
 227                 else
 228                         return error(_("invalid option: %s"), argv[1]);
 229                 argv++; argc--;
 230         }
 231
 232         /*
 233          * "diff --base" should not combine merges because it was not
 234          * asked to.  "diff -c" should not densify (if the user wants
 235          * dense one, --cc can be explicitly asked for, or just rely
 236          * on the default).
 237          */
 238         if (revs->max_count == -1 && !revs->combine_merges &&
 239             (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
 240                 revs->combine_merges = revs->dense_combined_merges = 1;
 241
 242         setup_work_tree();
 243         if (read_cache_preload(&revs->diffopt.pathspec) < 0) {
 244                 perror("read_cache_preload");
 245                 return -1;
 246         }
 247         return run_diff_files(revs, options);
 248 }
 249
 250 int cmd_diff(int argc, const char **argv, const char *prefix)
 251 {
 252         int i;
 253         struct rev_info rev;
 254         struct object_array ent = OBJECT_ARRAY_INIT;
 255         int blobs = 0, paths = 0;
 256         struct object_array_entry *blob[2];
 257         int nongit = 0, no_index = 0;
 258         int result = 0;
 259
 260         /*
 261          * We could get N tree-ish in the rev.pending_objects list.
 262          * Also there could be M blobs there, and P pathspecs.
 263          *
 264          * N=0, M=0:
 265          *      cache vs files (diff-files)
 266          * N=0, M=2:
 267          *      compare two random blobs.  P must be zero.
 268          * N=0, M=1, P=1:
 269          *      compare a blob with a working tree file.
 270          *
 271          * N=1, M=0:
 272          *      tree vs cache (diff-index --cached)
 273          *
 274          * N=2, M=0:
 275          *      tree vs tree (diff-tree)
 276          *
 277          * N=0, M=0, P=2:
 278          *      compare two filesystem entities (aka --no-index).
 279          *
 280          * Other cases are errors.
 281          */
 282
 283         /* Were we asked to do --no-index explicitly? */
 284         for (i = 1; i < argc; i++) {
 285                 if (!strcmp(argv[i], "--")) {
 286                         i++;
 287                         break;
 288                 }
 289                 if (!strcmp(argv[i], "--no-index"))
 290                         no_index = DIFF_NO_INDEX_EXPLICIT;
 291                 if (argv[i][0] != '-')
 292                         break;
 293         }
 294
 295         prefix = setup_git_directory_gently(&nongit);
 296
 297         if (!no_index) {
 298                 /*
 299                  * Treat git diff with at least one path outside of the
 300                  * repo the same as if the command would have been executed
 301                  * outside of a git repository.  In this case it behaves
 302                  * the same way as "git diff --no-index <a> <b>", which acts
 303                  * as a colourful "diff" replacement.
 304                  */
 305                 if (nongit || ((argc == i + 2) &&
 306                                (!path_inside_repo(prefix, argv[i]) ||
 307                                 !path_inside_repo(prefix, argv[i + 1]))))
 308                         no_index = DIFF_NO_INDEX_IMPLICIT;
 309         }
 310
 311         if (!no_index)
 312                 gitmodules_config();
 313         init_diff_ui_defaults();
 314         git_config(git_diff_ui_config, NULL);
 315         precompose_argv(argc, argv);
 316
 317         init_revisions(&rev, prefix);
 318
 319         if (no_index && argc != i + 2) {
 320                 if (no_index == DIFF_NO_INDEX_IMPLICIT) {
 321                         /*
 322                          * There was no --no-index and there were not two
 323                          * paths. It is possible that the user intended
 324                          * to do an inside-repository operation.
 325                          */
 326                         fprintf(stderr, "Not a git repository\n");
 327                         fprintf(stderr,
 328                                 "To compare two paths outside a working tree:\n");
 329                 }
 330                 /* Give the usage message for non-repository usage and exit. */
 331                 usagef("git diff %s <path> <path>",
 332                        no_index == DIFF_NO_INDEX_EXPLICIT ?
 333                        "--no-index" : "[--no-index]");
 334
 335         }
 336         if (no_index)
 337                 /* If this is a no-index diff, just run it and exit there. */
 338                 diff_no_index(&rev, argc, argv);
 339
 340         /* Otherwise, we are doing the usual "git" diff */
 341         rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
 342
 343         /* Scale to real terminal size and respect statGraphWidth config */
 344         rev.diffopt.stat_width = -1;
 345         rev.diffopt.stat_graph_width = -1;
 346
 347         /* Default to let external and textconv be used */
 348         DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
 349         DIFF_OPT_SET(&rev.diffopt, ALLOW_TEXTCONV);
 350
 351         if (nongit)
 352                 die(_("Not a git repository"));
 353         argc = setup_revisions(argc, argv, &rev, NULL);
 354         if (!rev.diffopt.output_format) {
 355                 rev.diffopt.output_format = DIFF_FORMAT_PATCH;
 356                 diff_setup_done(&rev.diffopt);
 357         }
 358
 359         DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
 360
 361         setup_diff_pager(&rev.diffopt);
 362
 363         /*
 364          * Do we have --cached and not have a pending object, then
 365          * default to HEAD by hand.  Eek.
 366          */
 367         if (!rev.pending.nr) {
 368                 int i;
 369                 for (i = 1; i < argc; i++) {
 370                         const char *arg = argv[i];
 371                         if (!strcmp(arg, "--"))
 372                                 break;
 373                         else if (!strcmp(arg, "--cached") ||
 374                                  !strcmp(arg, "--staged")) {
 375                                 add_head_to_pending(&rev);
 376                                 if (!rev.pending.nr) {
 377                                         struct tree *tree;
 378                                         tree = lookup_tree(EMPTY_TREE_SHA1_BIN);
 379                                         add_pending_object(&rev, &tree->object, "HEAD");
 380                                 }
 381                                 break;
 382                         }
 383                 }
 384         }
 385
 386         for (i = 0; i < rev.pending.nr; i++) {
 387                 struct object_array_entry *entry = &rev.pending.objects[i];
 388                 struct object *obj = entry->item;
 389                 const char *name = entry->name;
 390                 int flags = (obj->flags & UNINTERESTING);
 391                 if (!obj->parsed)
 392                         obj = parse_object(obj->oid.hash);
 393                 obj = deref_tag(obj, NULL, 0);
 394                 if (!obj)
 395                         die(_("invalid object '%s' given."), name);
 396                 if (obj->type == OBJ_COMMIT)
 397                         obj = &((struct commit *)obj)->tree->object;
 398
 399                 if (obj->type == OBJ_TREE) {
 400                         obj->flags |= flags;
 401                         add_object_array(obj, name, &ent);
 402                 } else if (obj->type == OBJ_BLOB) {
 403                         if (2 <= blobs)
 404                                 die(_("more than two blobs given: '%s'"), name);
 405                         blob[blobs] = entry;
 406                         blobs++;
 407
 408                 } else {
 409                         die(_("unhandled object '%s' given."), name);
 410                 }
 411         }
 412         if (rev.prune_data.nr)
 413                 paths += rev.prune_data.nr;
 414
 415         /*
 416          * Now, do the arguments look reasonable?
 417          */
 418         if (!ent.nr) {
 419                 switch (blobs) {
 420                 case 0:
 421                         result = builtin_diff_files(&rev, argc, argv);
 422                         break;
 423                 case 1:
 424                         if (paths != 1)
 425                                 usage(builtin_diff_usage);
 426                         result = builtin_diff_b_f(&rev, argc, argv, blob);
 427                         break;
 428                 case 2:
 429                         if (paths)
 430                                 usage(builtin_diff_usage);
 431                         result = builtin_diff_blobs(&rev, argc, argv, blob);
 432                         break;
 433                 default:
 434                         usage(builtin_diff_usage);
 435                 }
 436         }
 437         else if (blobs)
 438                 usage(builtin_diff_usage);
 439         else if (ent.nr == 1)
 440                 result = builtin_diff_index(&rev, argc, argv);
 441         else if (ent.nr == 2)
 442                 result = builtin_diff_tree(&rev, argc, argv,
 443                                            &ent.objects[0], &ent.objects[1]);
 444         else if (ent.objects[0].item->flags & UNINTERESTING) {
 445                 /*
 446                  * diff A...B where there is at least one merge base
 447                  * between A and B.  We have ent.objects[0] ==
 448                  * merge-base, ent.objects[ents-2] == A, and
 449                  * ent.objects[ents-1] == B.  Show diff between the
 450                  * base and B.  Note that we pick one merge base at
 451                  * random if there are more than one.
 452                  */
 453                 result = builtin_diff_tree(&rev, argc, argv,
 454                                            &ent.objects[0],
 455                                            &ent.objects[ent.nr-1]);
 456         } else
 457                 result = builtin_diff_combined(&rev, argc, argv,
 458                                                ent.objects, ent.nr);
 459         result = diff_result_code(&rev.diffopt, result);
 460         if (1 < rev.diffopt.skip_stat_unmatch)
 461                 refresh_index_quietly();
 462         return result;
 463 }