builtin/diff.c

   1 /*
   2  * Builtin "git diff"
   3  *
   4  * Copyright (c) 2006 Junio C Hamano
   5  */
   6 #include "cache.h"
   7 #include "color.h"
   8 #include "commit.h"
   9 #include "blob.h"
  10 #include "tag.h"
  11 #include "diff.h"
  12 #include "diffcore.h"
  13 #include "revision.h"
  14 #include "log-tree.h"
  15 #include "builtin.h"
  16 #include "submodule.h"
  17 #include "sha1-array.h"
  18
  19 #define DIFF_NO_INDEX_EXPLICIT 1
  20 #define DIFF_NO_INDEX_IMPLICIT 2
  21
  22 struct blobinfo {
  23         unsigned char sha1[20];
  24         const char *name;
  25         unsigned mode;
  26 };
  27
  28 static const char builtin_diff_usage[] =
  29 "git diff [<options>] [<commit> [<commit>]] [--] [<path>...]";
  30
  31 static void stuff_change(struct diff_options *opt,
  32                          unsigned old_mode, unsigned new_mode,
  33                          const unsigned char *old_sha1,
  34                          const unsigned char *new_sha1,
  35                          int old_sha1_valid,
  36                          int new_sha1_valid,
  37                          const char *old_name,
  38                          const char *new_name)
  39 {
  40         struct diff_filespec *one, *two;
  41
  42         if (!is_null_sha1(old_sha1) && !is_null_sha1(new_sha1) &&
  43             !hashcmp(old_sha1, new_sha1) && (old_mode == new_mode))
  44                 return;
  45
  46         if (DIFF_OPT_TST(opt, REVERSE_DIFF)) {
  47                 unsigned tmp;
  48                 const unsigned char *tmp_u;
  49                 const char *tmp_c;
  50                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
  51                 tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
  52                 tmp_c = old_name; old_name = new_name; new_name = tmp_c;
  53         }
  54
  55         if (opt->prefix &&
  56             (strncmp(old_name, opt->prefix, opt->prefix_length) ||
  57              strncmp(new_name, opt->prefix, opt->prefix_length)))
  58                 return;
  59
  60         one = alloc_filespec(old_name);
  61         two = alloc_filespec(new_name);
  62         fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
  63         fill_filespec(two, new_sha1, new_sha1_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 blobinfo *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].sha1, null_sha1,
  95                      1, 0,
  96                      path, path);
  97         diffcore_std(&revs->diffopt);
  98         diff_flush(&revs->diffopt);
  99         return 0;
 100 }
 101
 102 static int builtin_diff_blobs(struct rev_info *revs,
 103                               int argc, const char **argv,
 104                               struct blobinfo *blob)
 105 {
 106         unsigned mode = canon_mode(S_IFREG | 0644);
 107
 108         if (argc > 1)
 109                 usage(builtin_diff_usage);
 110
 111         if (blob[0].mode == S_IFINVALID)
 112                 blob[0].mode = mode;
 113
 114         if (blob[1].mode == S_IFINVALID)
 115                 blob[1].mode = mode;
 116
 117         stuff_change(&revs->diffopt,
 118                      blob[0].mode, blob[1].mode,
 119                      blob[0].sha1, blob[1].sha1,
 120                      1, 1,
 121                      blob[0].name, blob[1].name);
 122         diffcore_std(&revs->diffopt);
 123         diff_flush(&revs->diffopt);
 124         return 0;
 125 }
 126
 127 static int builtin_diff_index(struct rev_info *revs,
 128                               int argc, const char **argv)
 129 {
 130         int cached = 0;
 131         while (1 < argc) {
 132                 const char *arg = argv[1];
 133                 if (!strcmp(arg, "--cached") || !strcmp(arg, "--staged"))
 134                         cached = 1;
 135                 else
 136                         usage(builtin_diff_usage);
 137                 argv++; argc--;
 138         }
 139         /*
 140          * Make sure there is one revision (i.e. pending object),
 141          * and there is no revision filtering parameters.
 142          */
 143         if (revs->pending.nr != 1 ||
 144             revs->max_count != -1 || revs->min_age != -1 ||
 145             revs->max_age != -1)
 146                 usage(builtin_diff_usage);
 147         if (!cached) {
 148                 setup_work_tree();
 149                 if (read_cache_preload(&revs->diffopt.pathspec) < 0) {
 150                         perror("read_cache_preload");
 151                         return -1;
 152                 }
 153         } else if (read_cache() < 0) {
 154                 perror("read_cache");
 155                 return -1;
 156         }
 157         return run_diff_index(revs, cached);
 158 }
 159
 160 static int builtin_diff_tree(struct rev_info *revs,
 161                              int argc, const char **argv,
 162                              struct object_array_entry *ent0,
 163                              struct object_array_entry *ent1)
 164 {
 165         const unsigned char *(sha1[2]);
 166         int swap = 0;
 167
 168         if (argc > 1)
 169                 usage(builtin_diff_usage);
 170
 171         /*
 172          * We saw two trees, ent0 and ent1.  If ent1 is uninteresting,
 173          * swap them.
 174          */
 175         if (ent1->item->flags & UNINTERESTING)
 176                 swap = 1;
 177         sha1[swap] = ent0->item->sha1;
 178         sha1[1 - swap] = ent1->item->sha1;
 179         diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
 180         log_tree_diff_flush(revs);
 181         return 0;
 182 }
 183
 184 static int builtin_diff_combined(struct rev_info *revs,
 185                                  int argc, const char **argv,
 186                                  struct object_array_entry *ent,
 187                                  int ents)
 188 {
 189         struct sha1_array parents = SHA1_ARRAY_INIT;
 190         int i;
 191
 192         if (argc > 1)
 193                 usage(builtin_diff_usage);
 194
 195         if (!revs->dense_combined_merges && !revs->combine_merges)
 196                 revs->dense_combined_merges = revs->combine_merges = 1;
 197         for (i = 1; i < ents; i++)
 198                 sha1_array_append(&parents, ent[i].item->sha1);
 199         diff_tree_combined(ent[0].item->sha1, &parents,
 200                            revs->dense_combined_merges, revs);
 201         sha1_array_clear(&parents);
 202         return 0;
 203 }
 204
 205 static void refresh_index_quietly(void)
 206 {
 207         struct lock_file *lock_file;
 208         int fd;
 209
 210         lock_file = xcalloc(1, sizeof(struct lock_file));
 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         update_index_if_able(&the_index, 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 int cmd_diff(int argc, const char **argv, const char *prefix)
 259 {
 260         int i;
 261         struct rev_info rev;
 262         struct object_array ent = OBJECT_ARRAY_INIT;
 263         int blobs = 0, paths = 0;
 264         struct blobinfo blob[2];
 265         int nongit = 0, no_index = 0;
 266         int result = 0;
 267
 268         /*
 269          * We could get N tree-ish in the rev.pending_objects list.
 270          * Also there could be M blobs there, and P pathspecs.
 271          *
 272          * N=0, M=0:
 273          *      cache vs files (diff-files)
 274          * N=0, M=2:
 275          *      compare two random blobs.  P must be zero.
 276          * N=0, M=1, P=1:
 277          *      compare a blob with a working tree file.
 278          *
 279          * N=1, M=0:
 280          *      tree vs cache (diff-index --cached)
 281          *
 282          * N=2, M=0:
 283          *      tree vs tree (diff-tree)
 284          *
 285          * N=0, M=0, P=2:
 286          *      compare two filesystem entities (aka --no-index).
 287          *
 288          * Other cases are errors.
 289          */
 290
 291         /* Were we asked to do --no-index explicitly? */
 292         for (i = 1; i < argc; i++) {
 293                 if (!strcmp(argv[i], "--")) {
 294                         i++;
 295                         break;
 296                 }
 297                 if (!strcmp(argv[i], "--no-index"))
 298                         no_index = DIFF_NO_INDEX_EXPLICIT;
 299                 if (argv[i][0] != '-')
 300                         break;
 301         }
 302
 303         if (!no_index)
 304                 prefix = setup_git_directory_gently(&nongit);
 305
 306         /*
 307          * Treat git diff with at least one path outside of the
 308          * repo the same as if the command would have been executed
 309          * outside of a git repository.  In this case it behaves
 310          * the same way as "git diff --no-index <a> <b>", which acts
 311          * as a colourful "diff" replacement.
 312          */
 313         if (nongit || ((argc == i + 2) &&
 314                        (!path_inside_repo(prefix, argv[i]) ||
 315                         !path_inside_repo(prefix, argv[i + 1]))))
 316                 no_index = DIFF_NO_INDEX_IMPLICIT;
 317
 318         if (!no_index)
 319                 gitmodules_config();
 320         git_config(git_diff_ui_config, NULL);
 321
 322         init_revisions(&rev, prefix);
 323
 324         if (no_index && argc != i + 2) {
 325                 if (no_index == DIFF_NO_INDEX_IMPLICIT) {
 326                         /*
 327                          * There was no --no-index and there were not two
 328                          * paths. It is possible that the user intended
 329                          * to do an inside-repository operation.
 330                          */
 331                         fprintf(stderr, "Not a git repository\n");
 332                         fprintf(stderr,
 333                                 "To compare two paths outside a working tree:\n");
 334                 }
 335                 /* Give the usage message for non-repository usage and exit. */
 336                 usagef("git diff %s <path> <path>",
 337                        no_index == DIFF_NO_INDEX_EXPLICIT ?
 338                        "--no-index" : "[--no-index]");
 339
 340         }
 341         if (no_index)
 342                 /* If this is a no-index diff, just run it and exit there. */
 343                 diff_no_index(&rev, argc, argv, prefix);
 344
 345         /* Otherwise, we are doing the usual "git" diff */
 346         rev.diffopt.skip_stat_unmatch = !!diff_auto_refresh_index;
 347
 348         /* Scale to real terminal size and respect statGraphWidth config */
 349         rev.diffopt.stat_width = -1;
 350         rev.diffopt.stat_graph_width = -1;
 351
 352         /* Default to let external and textconv be used */
 353         DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
 354         DIFF_OPT_SET(&rev.diffopt, ALLOW_TEXTCONV);
 355
 356         if (nongit)
 357                 die(_("Not a git repository"));
 358         argc = setup_revisions(argc, argv, &rev, NULL);
 359         if (!rev.diffopt.output_format) {
 360                 rev.diffopt.output_format = DIFF_FORMAT_PATCH;
 361                 diff_setup_done(&rev.diffopt);
 362         }
 363
 364         DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
 365
 366         setup_diff_pager(&rev.diffopt);
 367
 368         /*
 369          * Do we have --cached and not have a pending object, then
 370          * default to HEAD by hand.  Eek.
 371          */
 372         if (!rev.pending.nr) {
 373                 int i;
 374                 for (i = 1; i < argc; i++) {
 375                         const char *arg = argv[i];
 376                         if (!strcmp(arg, "--"))
 377                                 break;
 378                         else if (!strcmp(arg, "--cached") ||
 379                                  !strcmp(arg, "--staged")) {
 380                                 add_head_to_pending(&rev);
 381                                 if (!rev.pending.nr) {
 382                                         struct tree *tree;
 383                                         tree = lookup_tree(EMPTY_TREE_SHA1_BIN);
 384                                         add_pending_object(&rev, &tree->object, "HEAD");
 385                                 }
 386                                 break;
 387                         }
 388                 }
 389         }
 390
 391         for (i = 0; i < rev.pending.nr; i++) {
 392                 struct object_array_entry *entry = &rev.pending.objects[i];
 393                 struct object *obj = entry->item;
 394                 const char *name = entry->name;
 395                 int flags = (obj->flags & UNINTERESTING);
 396                 if (!obj->parsed)
 397                         obj = parse_object(obj->sha1);
 398                 obj = deref_tag(obj, NULL, 0);
 399                 if (!obj)
 400                         die(_("invalid object '%s' given."), name);
 401                 if (obj->type == OBJ_COMMIT)
 402                         obj = &((struct commit *)obj)->tree->object;
 403
 404                 if (obj->type == OBJ_TREE) {
 405                         obj->flags |= flags;
 406                         add_object_array(obj, name, &ent);
 407                 } else if (obj->type == OBJ_BLOB) {
 408                         if (2 <= blobs)
 409                                 die(_("more than two blobs given: '%s'"), name);
 410                         hashcpy(blob[blobs].sha1, obj->sha1);
 411                         blob[blobs].name = name;
 412                         blob[blobs].mode = entry->mode;
 413                         blobs++;
 414
 415                 } else {
 416                         die(_("unhandled object '%s' given."), name);
 417                 }
 418         }
 419         if (rev.prune_data.nr)
 420                 paths += rev.prune_data.nr;
 421
 422         /*
 423          * Now, do the arguments look reasonable?
 424          */
 425         if (!ent.nr) {
 426                 switch (blobs) {
 427                 case 0:
 428                         result = builtin_diff_files(&rev, argc, argv);
 429                         break;
 430                 case 1:
 431                         if (paths != 1)
 432                                 usage(builtin_diff_usage);
 433                         result = builtin_diff_b_f(&rev, argc, argv, blob);
 434                         break;
 435                 case 2:
 436                         if (paths)
 437                                 usage(builtin_diff_usage);
 438                         result = builtin_diff_blobs(&rev, argc, argv, blob);
 439                         break;
 440                 default:
 441                         usage(builtin_diff_usage);
 442                 }
 443         }
 444         else if (blobs)
 445                 usage(builtin_diff_usage);
 446         else if (ent.nr == 1)
 447                 result = builtin_diff_index(&rev, argc, argv);
 448         else if (ent.nr == 2)
 449                 result = builtin_diff_tree(&rev, argc, argv,
 450                                            &ent.objects[0], &ent.objects[1]);
 451         else if (ent.objects[0].item->flags & UNINTERESTING) {
 452                 /*
 453                  * diff A...B where there is at least one merge base
 454                  * between A and B.  We have ent.objects[0] ==
 455                  * merge-base, ent.objects[ents-2] == A, and
 456                  * ent.objects[ents-1] == B.  Show diff between the
 457                  * base and B.  Note that we pick one merge base at
 458                  * random if there are more than one.
 459                  */
 460                 result = builtin_diff_tree(&rev, argc, argv,
 461                                            &ent.objects[0],
 462                                            &ent.objects[ent.nr-1]);
 463         } else
 464                 result = builtin_diff_combined(&rev, argc, argv,
 465                                                ent.objects, ent.nr);
 466         result = diff_result_code(&rev.diffopt, result);
 467         if (1 < rev.diffopt.skip_stat_unmatch)
 468                 refresh_index_quietly();
 469         return result;
 470 }