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                             const char *path)
  72 {
  73         /* Blob vs file in the working tree*/
  74         struct stat st;
  75
  76         if (argc > 1)
  77                 usage(builtin_diff_usage);
  78
  79         if (lstat(path, &st))
  80                 die_errno(_("failed to stat '%s'"), path);
  81         if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
  82                 die(_("'%s': not a regular file or symlink"), path);
  83
  84         diff_set_mnemonic_prefix(&revs->diffopt, "o/", "w/");
  85
  86         if (blob[0].mode == S_IFINVALID)
  87                 blob[0].mode = canon_mode(st.st_mode);
  88
  89         stuff_change(&revs->diffopt,
  90                      blob[0].mode, canon_mode(st.st_mode),
  91                      blob[0].sha1, null_sha1,
  92                      1, 0,
  93                      path, path);
  94         diffcore_std(&revs->diffopt);
  95         diff_flush(&revs->diffopt);
  96         return 0;
  97 }
  98
  99 static int builtin_diff_blobs(struct rev_info *revs,
 100                               int argc, const char **argv,
 101                               struct blobinfo *blob)
 102 {
 103         unsigned mode = canon_mode(S_IFREG | 0644);
 104
 105         if (argc > 1)
 106                 usage(builtin_diff_usage);
 107
 108         if (blob[0].mode == S_IFINVALID)
 109                 blob[0].mode = mode;
 110
 111         if (blob[1].mode == S_IFINVALID)
 112                 blob[1].mode = mode;
 113
 114         stuff_change(&revs->diffopt,
 115                      blob[0].mode, blob[1].mode,
 116                      blob[0].sha1, blob[1].sha1,
 117                      1, 1,
 118                      blob[0].name, blob[1].name);
 119         diffcore_std(&revs->diffopt);
 120         diff_flush(&revs->diffopt);
 121         return 0;
 122 }
 123
 124 static int builtin_diff_index(struct rev_info *revs,
 125                               int argc, const char **argv)
 126 {
 127         int cached = 0;
 128         while (1 < argc) {
 129                 const char *arg = argv[1];
 130                 if (!strcmp(arg, "--cached") || !strcmp(arg, "--staged"))
 131                         cached = 1;
 132                 else
 133                         usage(builtin_diff_usage);
 134                 argv++; argc--;
 135         }
 136         /*
 137          * Make sure there is one revision (i.e. pending object),
 138          * and there is no revision filtering parameters.
 139          */
 140         if (revs->pending.nr != 1 ||
 141             revs->max_count != -1 || revs->min_age != -1 ||
 142             revs->max_age != -1)
 143                 usage(builtin_diff_usage);
 144         if (!cached) {
 145                 setup_work_tree();
 146                 if (read_cache_preload(&revs->diffopt.pathspec) < 0) {
 147                         perror("read_cache_preload");
 148                         return -1;
 149                 }
 150         } else if (read_cache() < 0) {
 151                 perror("read_cache");
 152                 return -1;
 153         }
 154         return run_diff_index(revs, cached);
 155 }
 156
 157 static int builtin_diff_tree(struct rev_info *revs,
 158                              int argc, const char **argv,
 159                              struct object_array_entry *ent0,
 160                              struct object_array_entry *ent1)
 161 {
 162         const unsigned char *(sha1[2]);
 163         int swap = 0;
 164
 165         if (argc > 1)
 166                 usage(builtin_diff_usage);
 167
 168         /*
 169          * We saw two trees, ent0 and ent1.  If ent1 is uninteresting,
 170          * swap them.
 171          */
 172         if (ent1->item->flags & UNINTERESTING)
 173                 swap = 1;
 174         sha1[swap] = ent0->item->sha1;
 175         sha1[1 - swap] = ent1->item->sha1;
 176         diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
 177         log_tree_diff_flush(revs);
 178         return 0;
 179 }
 180
 181 static int builtin_diff_combined(struct rev_info *revs,
 182                                  int argc, const char **argv,
 183                                  struct object_array_entry *ent,
 184                                  int ents)
 185 {
 186         struct sha1_array parents = SHA1_ARRAY_INIT;
 187         int i;
 188
 189         if (argc > 1)
 190                 usage(builtin_diff_usage);
 191
 192         if (!revs->dense_combined_merges && !revs->combine_merges)
 193                 revs->dense_combined_merges = revs->combine_merges = 1;
 194         for (i = 1; i < ents; i++)
 195                 sha1_array_append(&parents, ent[i].item->sha1);
 196         diff_tree_combined(ent[0].item->sha1, &parents,
 197                            revs->dense_combined_merges, revs);
 198         sha1_array_clear(&parents);
 199         return 0;
 200 }
 201
 202 static void refresh_index_quietly(void)
 203 {
 204         struct lock_file *lock_file;
 205         int fd;
 206
 207         lock_file = xcalloc(1, sizeof(struct lock_file));
 208         fd = hold_locked_index(lock_file, 0);
 209         if (fd < 0)
 210                 return;
 211         discard_cache();
 212         read_cache();
 213         refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
 214         update_index_if_able(&the_index, lock_file);
 215 }
 216
 217 static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv)
 218 {
 219         unsigned int options = 0;
 220
 221         while (1 < argc && argv[1][0] == '-') {
 222                 if (!strcmp(argv[1], "--base"))
 223                         revs->max_count = 1;
 224                 else if (!strcmp(argv[1], "--ours"))
 225                         revs->max_count = 2;
 226                 else if (!strcmp(argv[1], "--theirs"))
 227                         revs->max_count = 3;
 228                 else if (!strcmp(argv[1], "-q"))
 229                         options |= DIFF_SILENT_ON_REMOVED;
 230                 else if (!strcmp(argv[1], "-h"))
 231                         usage(builtin_diff_usage);
 232                 else
 233                         return error(_("invalid option: %s"), argv[1]);
 234                 argv++; argc--;
 235         }
 236
 237         /*
 238          * "diff --base" should not combine merges because it was not
 239          * asked to.  "diff -c" should not densify (if the user wants
 240          * dense one, --cc can be explicitly asked for, or just rely
 241          * on the default).
 242          */
 243         if (revs->max_count == -1 && !revs->combine_merges &&
 244             (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
 245                 revs->combine_merges = revs->dense_combined_merges = 1;
 246
 247         setup_work_tree();
 248         if (read_cache_preload(&revs->diffopt.pathspec) < 0) {
 249                 perror("read_cache_preload");
 250                 return -1;
 251         }
 252         return run_diff_files(revs, options);
 253 }
 254
 255 int cmd_diff(int argc, const char **argv, const char *prefix)
 256 {
 257         int i;
 258         struct rev_info rev;
 259         struct object_array ent = OBJECT_ARRAY_INIT;
 260         int blobs = 0, paths = 0;
 261         const char *path = NULL;
 262         struct blobinfo 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         if (!no_index)
 302                 prefix = setup_git_directory_gently(&nongit);
 303
 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         if (!no_index)
 317                 gitmodules_config();
 318         git_config(git_diff_ui_config, NULL);
 319
 320         init_revisions(&rev, prefix);
 321
 322         if (no_index) {
 323                 if (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 this is a no-index diff, just run it and exit there. */
 341                 diff_no_index(&rev, argc, argv, prefix);
 342         }
 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         DIFF_OPT_SET(&rev.diffopt, ALLOW_EXTERNAL);
 353         DIFF_OPT_SET(&rev.diffopt, ALLOW_TEXTCONV);
 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         DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
 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(EMPTY_TREE_SHA1_BIN);
 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->sha1);
 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                         hashcpy(blob[blobs].sha1, obj->sha1);
 410                         blob[blobs].name = name;
 411                         blob[blobs].mode = entry->mode;
 412                         blobs++;
 413
 414                 } else {
 415                         die(_("unhandled object '%s' given."), name);
 416                 }
 417         }
 418         if (rev.prune_data.nr) {
 419                 /* builtin_diff_b_f() */
 420                 GUARD_PATHSPEC(&rev.prune_data, PATHSPEC_FROMTOP | PATHSPEC_LITERAL);
 421                 if (!path)
 422                         path = rev.prune_data.items[0].match;
 423                 paths += rev.prune_data.nr;
 424         }
 425
 426         /*
 427          * Now, do the arguments look reasonable?
 428          */
 429         if (!ent.nr) {
 430                 switch (blobs) {
 431                 case 0:
 432                         result = builtin_diff_files(&rev, argc, argv);
 433                         break;
 434                 case 1:
 435                         if (paths != 1)
 436                                 usage(builtin_diff_usage);
 437                         result = builtin_diff_b_f(&rev, argc, argv, blob, path);
 438                         break;
 439                 case 2:
 440                         if (paths)
 441                                 usage(builtin_diff_usage);
 442                         result = builtin_diff_blobs(&rev, argc, argv, blob);
 443                         break;
 444                 default:
 445                         usage(builtin_diff_usage);
 446                 }
 447         }
 448         else if (blobs)
 449                 usage(builtin_diff_usage);
 450         else if (ent.nr == 1)
 451                 result = builtin_diff_index(&rev, argc, argv);
 452         else if (ent.nr == 2)
 453                 result = builtin_diff_tree(&rev, argc, argv,
 454                                            &ent.objects[0], &ent.objects[1]);
 455         else if (ent.objects[0].item->flags & UNINTERESTING) {
 456                 /*
 457                  * diff A...B where there is at least one merge base
 458                  * between A and B.  We have ent.objects[0] ==
 459                  * merge-base, ent.objects[ents-2] == A, and
 460                  * ent.objects[ents-1] == B.  Show diff between the
 461                  * base and B.  Note that we pick one merge base at
 462                  * random if there are more than one.
 463                  */
 464                 result = builtin_diff_tree(&rev, argc, argv,
 465                                            &ent.objects[0],
 466                                            &ent.objects[ent.nr-1]);
 467         } else
 468                 result = builtin_diff_combined(&rev, argc, argv,
 469                                                ent.objects, ent.nr);
 470         result = diff_result_code(&rev.diffopt, result);
 471         if (1 < rev.diffopt.skip_stat_unmatch)
 472                 refresh_index_quietly();
 473         return result;
 474 }