builtin/diff.c

   1 /*
   2  * Builtin "git diff"
   3  *
   4  * Copyright (c) 2006 Junio C Hamano
   5  */
   6 #include "cache.h"
   7 #include "config.h"
   8 #include "lockfile.h"
   9 #include "color.h"
  10 #include "commit.h"
  11 #include "blob.h"
  12 #include "tag.h"
  13 #include "diff.h"
  14 #include "diffcore.h"
  15 #include "revision.h"
  16 #include "log-tree.h"
  17 #include "builtin.h"
  18 #include "submodule.h"
  19 #include "sha1-array.h"
  20
  21 #define DIFF_NO_INDEX_EXPLICIT 1
  22 #define DIFF_NO_INDEX_IMPLICIT 2
  23
  24 static const char builtin_diff_usage[] =
  25 "git diff [<options>] [<commit> [<commit>]] [--] [<path>...]";
  26
  27 static const char *blob_path(struct object_array_entry *entry)
  28 {
  29         return entry->path ? entry->path : entry->name;
  30 }
  31
  32 static void stuff_change(struct diff_options *opt,
  33                          unsigned old_mode, unsigned new_mode,
  34                          const struct object_id *old_oid,
  35                          const struct object_id *new_oid,
  36                          int old_oid_valid,
  37                          int new_oid_valid,
  38                          const char *old_path,
  39                          const char *new_path)
  40 {
  41         struct diff_filespec *one, *two;
  42
  43         if (!is_null_oid(old_oid) && !is_null_oid(new_oid) &&
  44             !oidcmp(old_oid, new_oid) && (old_mode == new_mode))
  45                 return;
  46
  47         if (opt->flags.reverse_diff) {
  48                 SWAP(old_mode, new_mode);
  49                 SWAP(old_oid, new_oid);
  50                 SWAP(old_path, new_path);
  51         }
  52
  53         if (opt->prefix &&
  54             (strncmp(old_path, opt->prefix, opt->prefix_length) ||
  55              strncmp(new_path, opt->prefix, opt->prefix_length)))
  56                 return;
  57
  58         one = alloc_filespec(old_path);
  59         two = alloc_filespec(new_path);
  60         fill_filespec(one, old_oid, old_oid_valid, old_mode);
  61         fill_filespec(two, new_oid, new_oid_valid, new_mode);
  62
  63         diff_queue(&diff_queued_diff, one, two);
  64 }
  65
  66 static int builtin_diff_b_f(struct rev_info *revs,
  67                             int argc, const char **argv,
  68                             struct object_array_entry **blob)
  69 {
  70         /* Blob vs file in the working tree*/
  71         struct stat st;
  72         const char *path;
  73
  74         if (argc > 1)
  75                 usage(builtin_diff_usage);
  76
  77         GUARD_PATHSPEC(&revs->prune_data, PATHSPEC_FROMTOP | PATHSPEC_LITERAL);
  78         path = revs->prune_data.items[0].match;
  79
  80         if (lstat(path, &st))
  81                 die_errno(_("failed to stat '%s'"), path);
  82         if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
  83                 die(_("'%s': not a regular file or symlink"), path);
  84
  85         diff_set_mnemonic_prefix(&revs->diffopt, "o/", "w/");
  86
  87         if (blob[0]->mode == S_IFINVALID)
  88                 blob[0]->mode = canon_mode(st.st_mode);
  89
  90         stuff_change(&revs->diffopt,
  91                      blob[0]->mode, canon_mode(st.st_mode),
  92                      &blob[0]->item->oid, &null_oid,
  93                      1, 0,
  94                      blob[0]->path ? blob[0]->path : path,
  95                      path);
  96         diffcore_std(&revs->diffopt);
  97         diff_flush(&revs->diffopt);
  98         return 0;
  99 }
 100
 101 static int builtin_diff_blobs(struct rev_info *revs,
 102                               int argc, const char **argv,
 103                               struct object_array_entry **blob)
 104 {
 105         unsigned mode = canon_mode(S_IFREG | 0644);
 106
 107         if (argc > 1)
 108                 usage(builtin_diff_usage);
 109
 110         if (blob[0]->mode == S_IFINVALID)
 111                 blob[0]->mode = mode;
 112
 113         if (blob[1]->mode == S_IFINVALID)
 114                 blob[1]->mode = mode;
 115
 116         stuff_change(&revs->diffopt,
 117                      blob[0]->mode, blob[1]->mode,
 118                      &blob[0]->item->oid, &blob[1]->item->oid,
 119                      1, 1,
 120                      blob_path(blob[0]), blob_path(blob[1]));
 121         diffcore_std(&revs->diffopt);
 122         diff_flush(&revs->diffopt);
 123         return 0;
 124 }
 125
 126 static int builtin_diff_index(struct rev_info *revs,
 127                               int argc, const char **argv)
 128 {
 129         int cached = 0;
 130         while (1 < argc) {
 131                 const char *arg = argv[1];
 132                 if (!strcmp(arg, "--cached") || !strcmp(arg, "--staged"))
 133                         cached = 1;
 134                 else
 135                         usage(builtin_diff_usage);
 136                 argv++; argc--;
 137         }
 138         /*
 139          * Make sure there is one revision (i.e. pending object),
 140          * and there is no revision filtering parameters.
 141          */
 142         if (revs->pending.nr != 1 ||
 143             revs->max_count != -1 || revs->min_age != -1 ||
 144             revs->max_age != -1)
 145                 usage(builtin_diff_usage);
 146         if (!cached) {
 147                 setup_work_tree();
 148                 if (read_cache_preload(&revs->diffopt.pathspec) < 0) {
 149                         perror("read_cache_preload");
 150                         return -1;
 151                 }
 152         } else if (read_cache() < 0) {
 153                 perror("read_cache");
 154                 return -1;
 155         }
 156         return run_diff_index(revs, cached);
 157 }
 158
 159 static int builtin_diff_tree(struct rev_info *revs,
 160                              int argc, const char **argv,
 161                              struct object_array_entry *ent0,
 162                              struct object_array_entry *ent1)
 163 {
 164         const struct object_id *(oid[2]);
 165         int swap = 0;
 166
 167         if (argc > 1)
 168                 usage(builtin_diff_usage);
 169
 170         /*
 171          * We saw two trees, ent0 and ent1.  If ent1 is uninteresting,
 172          * swap them.
 173          */
 174         if (ent1->item->flags & UNINTERESTING)
 175                 swap = 1;
 176         oid[swap] = &ent0->item->oid;
 177         oid[1 - swap] = &ent1->item->oid;
 178         diff_tree_oid(oid[0], oid[1], "", &revs->diffopt);
 179         log_tree_diff_flush(revs);
 180         return 0;
 181 }
 182
 183 static int builtin_diff_combined(struct rev_info *revs,
 184                                  int argc, const char **argv,
 185                                  struct object_array_entry *ent,
 186                                  int ents)
 187 {
 188         struct oid_array parents = OID_ARRAY_INIT;
 189         int i;
 190
 191         if (argc > 1)
 192                 usage(builtin_diff_usage);
 193
 194         if (!revs->dense_combined_merges && !revs->combine_merges)
 195                 revs->dense_combined_merges = revs->combine_merges = 1;
 196         for (i = 1; i < ents; i++)
 197                 oid_array_append(&parents, &ent[i].item->oid);
 198         diff_tree_combined(&ent[0].item->oid, &parents,
 199                            revs->dense_combined_merges, revs);
 200         oid_array_clear(&parents);
 201         return 0;
 202 }
 203
 204 static void refresh_index_quietly(void)
 205 {
 206         struct lock_file lock_file = LOCK_INIT;
 207         int fd;
 208
 209         fd = hold_locked_index(&lock_file, 0);
 210         if (fd < 0)
 211                 return;
 212         discard_cache();
 213         read_cache();
 214         refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
 215         update_index_if_able(&the_index, &lock_file);
 216 }
 217
 218 static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv)
 219 {
 220         unsigned int options = 0;
 221
 222         while (1 < argc && argv[1][0] == '-') {
 223                 if (!strcmp(argv[1], "--base"))
 224                         revs->max_count = 1;
 225                 else if (!strcmp(argv[1], "--ours"))
 226                         revs->max_count = 2;
 227                 else if (!strcmp(argv[1], "--theirs"))
 228                         revs->max_count = 3;
 229                 else if (!strcmp(argv[1], "-q"))
 230                         options |= DIFF_SILENT_ON_REMOVED;
 231                 else if (!strcmp(argv[1], "-h"))
 232                         usage(builtin_diff_usage);
 233                 else
 234                         return error(_("invalid option: %s"), argv[1]);
 235                 argv++; argc--;
 236         }
 237
 238         /*
 239          * "diff --base" should not combine merges because it was not
 240          * asked to.  "diff -c" should not densify (if the user wants
 241          * dense one, --cc can be explicitly asked for, or just rely
 242          * on the default).
 243          */
 244         if (revs->max_count == -1 && !revs->combine_merges &&
 245             (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
 246                 revs->combine_merges = revs->dense_combined_merges = 1;
 247
 248         setup_work_tree();
 249         if (read_cache_preload(&revs->diffopt.pathspec) < 0) {
 250                 perror("read_cache_preload");
 251                 return -1;
 252         }
 253         return run_diff_files(revs, options);
 254 }
 255
 256 int cmd_diff(int argc, const char **argv, const char *prefix)
 257 {
 258         int i;
 259         struct rev_info rev;
 260         struct object_array ent = OBJECT_ARRAY_INIT;
 261         int blobs = 0, paths = 0;
 262         struct object_array_entry *blob[2];
 263         int nongit = 0, no_index = 0;
 264         int result = 0;
 265
 266         /*
 267          * We could get N tree-ish in the rev.pending_objects list.
 268          * Also there could be M blobs there, and P pathspecs.
 269          *
 270          * N=0, M=0:
 271          *      cache vs files (diff-files)
 272          * N=0, M=2:
 273          *      compare two random blobs.  P must be zero.
 274          * N=0, M=1, P=1:
 275          *      compare a blob with a working tree file.
 276          *
 277          * N=1, M=0:
 278          *      tree vs cache (diff-index --cached)
 279          *
 280          * N=2, M=0:
 281          *      tree vs tree (diff-tree)
 282          *
 283          * N=0, M=0, P=2:
 284          *      compare two filesystem entities (aka --no-index).
 285          *
 286          * Other cases are errors.
 287          */
 288
 289         /* Were we asked to do --no-index explicitly? */
 290         for (i = 1; i < argc; i++) {
 291                 if (!strcmp(argv[i], "--")) {
 292                         i++;
 293                         break;
 294                 }
 295                 if (!strcmp(argv[i], "--no-index"))
 296                         no_index = DIFF_NO_INDEX_EXPLICIT;
 297                 if (argv[i][0] != '-')
 298                         break;
 299         }
 300
 301         prefix = setup_git_directory_gently(&nongit);
 302
 303         if (!no_index) {
 304                 /*
 305                  * Treat git diff with at least one path outside of the
 306                  * repo the same as if the command would have been executed
 307                  * outside of a git repository.  In this case it behaves
 308                  * the same way as "git diff --no-index <a> <b>", which acts
 309                  * as a colourful "diff" replacement.
 310                  */
 311                 if (nongit || ((argc == i + 2) &&
 312                                (!path_inside_repo(prefix, argv[i]) ||
 313                                 !path_inside_repo(prefix, argv[i + 1]))))
 314                         no_index = DIFF_NO_INDEX_IMPLICIT;
 315         }
 316
 317         init_diff_ui_defaults();
 318         git_config(git_diff_ui_config, NULL);
 319         precompose_argv(argc, argv);
 320
 321         init_revisions(&rev, prefix);
 322
 323         if (no_index && argc != i + 2) {
 324                 if (no_index == DIFF_NO_INDEX_IMPLICIT) {
 325                         /*
 326                          * There was no --no-index and there were not two
 327                          * paths. It is possible that the user intended
 328                          * to do an inside-repository operation.
 329                          */
 330                         fprintf(stderr, "Not a git repository\n");
 331                         fprintf(stderr,
 332                                 "To compare two paths outside a working tree:\n");
 333                 }
 334                 /* Give the usage message for non-repository usage and exit. */
 335                 usagef("git diff %s <path> <path>",
 336                        no_index == DIFF_NO_INDEX_EXPLICIT ?
 337                        "--no-index" : "[--no-index]");
 338
 339         }
 340         if (no_index)
 341                 /* If this is a no-index diff, just run it and exit there. */
 342                 diff_no_index(&rev, argc, argv);
 343
 344         /* Otherwise, we are doing the usual "git" diff */
 345         rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
 346
 347         /* Scale to real terminal size and respect statGraphWidth config */
 348         rev.diffopt.stat_width = -1;
 349         rev.diffopt.stat_graph_width = -1;
 350
 351         /* Default to let external and textconv be used */
 352         rev.diffopt.flags.allow_external = 1;
 353         rev.diffopt.flags.allow_textconv = 1;
 354
 355         if (nongit)
 356                 die(_("Not a git repository"));
 357         argc = setup_revisions(argc, argv, &rev, NULL);
 358         if (!rev.diffopt.output_format) {
 359                 rev.diffopt.output_format = DIFF_FORMAT_PATCH;
 360                 diff_setup_done(&rev.diffopt);
 361         }
 362
 363         rev.diffopt.flags.recursive = 1;
 364
 365         setup_diff_pager(&rev.diffopt);
 366
 367         /*
 368          * Do we have --cached and not have a pending object, then
 369          * default to HEAD by hand.  Eek.
 370          */
 371         if (!rev.pending.nr) {
 372                 int i;
 373                 for (i = 1; i < argc; i++) {
 374                         const char *arg = argv[i];
 375                         if (!strcmp(arg, "--"))
 376                                 break;
 377                         else if (!strcmp(arg, "--cached") ||
 378                                  !strcmp(arg, "--staged")) {
 379                                 add_head_to_pending(&rev);
 380                                 if (!rev.pending.nr) {
 381                                         struct tree *tree;
 382                                         tree = lookup_tree(the_hash_algo->empty_tree);
 383                                         add_pending_object(&rev, &tree->object, "HEAD");
 384                                 }
 385                                 break;
 386                         }
 387                 }
 388         }
 389
 390         for (i = 0; i < rev.pending.nr; i++) {
 391                 struct object_array_entry *entry = &rev.pending.objects[i];
 392                 struct object *obj = entry->item;
 393                 const char *name = entry->name;
 394                 int flags = (obj->flags & UNINTERESTING);
 395                 if (!obj->parsed)
 396                         obj = parse_object(&obj->oid);
 397                 obj = deref_tag(obj, NULL, 0);
 398                 if (!obj)
 399                         die(_("invalid object '%s' given."), name);
 400                 if (obj->type == OBJ_COMMIT)
 401                         obj = &((struct commit *)obj)->tree->object;
 402
 403                 if (obj->type == OBJ_TREE) {
 404                         obj->flags |= flags;
 405                         add_object_array(obj, name, &ent);
 406                 } else if (obj->type == OBJ_BLOB) {
 407                         if (2 <= blobs)
 408                                 die(_("more than two blobs given: '%s'"), name);
 409                         blob[blobs] = entry;
 410                         blobs++;
 411
 412                 } else {
 413                         die(_("unhandled object '%s' given."), name);
 414                 }
 415         }
 416         if (rev.prune_data.nr)
 417                 paths += rev.prune_data.nr;
 418
 419         /*
 420          * Now, do the arguments look reasonable?
 421          */
 422         if (!ent.nr) {
 423                 switch (blobs) {
 424                 case 0:
 425                         result = builtin_diff_files(&rev, argc, argv);
 426                         break;
 427                 case 1:
 428                         if (paths != 1)
 429                                 usage(builtin_diff_usage);
 430                         result = builtin_diff_b_f(&rev, argc, argv, blob);
 431                         break;
 432                 case 2:
 433                         if (paths)
 434                                 usage(builtin_diff_usage);
 435                         result = builtin_diff_blobs(&rev, argc, argv, blob);
 436                         break;
 437                 default:
 438                         usage(builtin_diff_usage);
 439                 }
 440         }
 441         else if (blobs)
 442                 usage(builtin_diff_usage);
 443         else if (ent.nr == 1)
 444                 result = builtin_diff_index(&rev, argc, argv);
 445         else if (ent.nr == 2)
 446                 result = builtin_diff_tree(&rev, argc, argv,
 447                                            &ent.objects[0], &ent.objects[1]);
 448         else if (ent.objects[0].item->flags & UNINTERESTING) {
 449                 /*
 450                  * diff A...B where there is at least one merge base
 451                  * between A and B.  We have ent.objects[0] ==
 452                  * merge-base, ent.objects[ents-2] == A, and
 453                  * ent.objects[ents-1] == B.  Show diff between the
 454                  * base and B.  Note that we pick one merge base at
 455                  * random if there are more than one.
 456                  */
 457                 result = builtin_diff_tree(&rev, argc, argv,
 458                                            &ent.objects[0],
 459                                            &ent.objects[ent.nr-1]);
 460         } else
 461                 result = builtin_diff_combined(&rev, argc, argv,
 462                                                ent.objects, ent.nr);
 463         result = diff_result_code(&rev.diffopt, result);
 464         if (1 < rev.diffopt.skip_stat_unmatch)
 465                 refresh_index_quietly();
 466         UNLEAK(rev);
 467         UNLEAK(ent);
 468         UNLEAK(blob);
 469         return result;
 470 }