diff-lib.c

   1 /*
   2  * Copyright (C) 2005 Junio C Hamano
   3  */
   4 #include "cache.h"
   5 #include "quote.h"
   6 #include "commit.h"
   7 #include "diff.h"
   8 #include "diffcore.h"
   9 #include "revision.h"
  10 #include "cache-tree.h"
  11 #include "path-list.h"
  12
  13 /*
  14  * diff-files
  15  */
  16
  17 static int read_directory(const char *path, struct path_list *list)
  18 {
  19         DIR *dir;
  20         struct dirent *e;
  21
  22         if (!(dir = opendir(path)))
  23                 return error("Could not open directory %s", path);
  24
  25         while ((e = readdir(dir)))
  26                 if (strcmp(".", e->d_name) && strcmp("..", e->d_name))
  27                         path_list_insert(xstrdup(e->d_name), list);
  28
  29         closedir(dir);
  30         return 0;
  31 }
  32
  33 static int queue_diff(struct diff_options *o,
  34                 const char *name1, const char *name2)
  35 {
  36         struct stat st;
  37         int mode1 = 0, mode2 = 0;
  38
  39         if (name1) {
  40                 if (!strcmp(name1, "-"))
  41                         mode1 = ntohl(create_ce_mode(0666));
  42                 else if (stat(name1, &st))
  43                         return error("Could not access '%s'", name1);
  44                 else
  45                         mode1 = st.st_mode;
  46         }
  47         if (name2) {
  48                 if (!strcmp(name2, "-"))
  49                         mode2 = ntohl(create_ce_mode(0666));
  50                 else if (stat(name2, &st))
  51                         return error("Could not access '%s'", name2);
  52                 else
  53                         mode2 = st.st_mode;
  54         }
  55
  56         if (mode1 && mode2 && S_ISDIR(mode1) != S_ISDIR(mode2))
  57                 return error("file/directory conflict: %s, %s", name1, name2);
  58
  59         if (S_ISDIR(mode1) || S_ISDIR(mode2)) {
  60                 char buffer1[PATH_MAX], buffer2[PATH_MAX];
  61                 struct path_list p1 = {NULL, 0, 0, 1}, p2 = {NULL, 0, 0, 1};
  62                 int len1 = 0, len2 = 0, i1, i2, ret = 0;
  63
  64                 if (name1 && read_directory(name1, &p1))
  65                         return -1;
  66                 if (name2 && read_directory(name2, &p2)) {
  67                         path_list_clear(&p1, 0);
  68                         return -1;
  69                 }
  70
  71                 if (name1) {
  72                         len1 = strlen(name1);
  73                         if (len1 > 0 && name1[len1 - 1] == '/')
  74                                 len1--;
  75                         memcpy(buffer1, name1, len1);
  76                         buffer1[len1++] = '/';
  77                 }
  78
  79                 if (name2) {
  80                         len2 = strlen(name2);
  81                         if (len2 > 0 && name2[len2 - 1] == '/')
  82                                 len2--;
  83                         memcpy(buffer2, name2, len2);
  84                         buffer2[len2++] = '/';
  85                 }
  86
  87                 for (i1 = i2 = 0; !ret && (i1 < p1.nr || i2 < p2.nr); ) {
  88                         const char *n1, *n2;
  89                         int comp;
  90
  91                         if (i1 == p1.nr)
  92                                 comp = 1;
  93                         else if (i2 == p2.nr)
  94                                 comp = -1;
  95                         else
  96                                 comp = strcmp(p1.items[i1].path,
  97                                         p2.items[i2].path);
  98
  99                         if (comp > 0)
 100                                 n1 = NULL;
 101                         else {
 102                                 n1 = buffer1;
 103                                 strncpy(buffer1 + len1, p1.items[i1++].path,
 104                                                 PATH_MAX - len1);
 105                         }
 106
 107                         if (comp < 0)
 108                                 n2 = NULL;
 109                         else {
 110                                 n2 = buffer2;
 111                                 strncpy(buffer2 + len2, p2.items[i2++].path,
 112                                                 PATH_MAX - len2);
 113                         }
 114
 115                         ret = queue_diff(o, n1, n2);
 116                 }
 117                 path_list_clear(&p1, 0);
 118                 path_list_clear(&p2, 0);
 119
 120                 return ret;
 121         } else {
 122                 struct diff_filespec *d1, *d2;
 123
 124                 if (o->reverse_diff) {
 125                         unsigned tmp;
 126                         const char *tmp_c;
 127                         tmp = mode1; mode1 = mode2; mode2 = tmp;
 128                         tmp_c = name1; name1 = name2; name2 = tmp_c;
 129                 }
 130
 131                 if (!name1)
 132                         name1 = "/dev/null";
 133                 if (!name2)
 134                         name2 = "/dev/null";
 135                 d1 = alloc_filespec(name1);
 136                 d2 = alloc_filespec(name2);
 137                 fill_filespec(d1, null_sha1, mode1);
 138                 fill_filespec(d2, null_sha1, mode2);
 139
 140                 diff_queue(&diff_queued_diff, d1, d2);
 141                 return 0;
 142         }
 143 }
 144
 145 static int is_in_index(const char *path)
 146 {
 147         int len = strlen(path);
 148         int pos = cache_name_pos(path, len);
 149         char c;
 150
 151         if (pos < 0)
 152                 return 0;
 153         if (strncmp(active_cache[pos]->name, path, len))
 154                 return 0;
 155         c = active_cache[pos]->name[len];
 156         return c == '\0' || c == '/';
 157 }
 158
 159 static int handle_diff_files_args(struct rev_info *revs,
 160                 int argc, const char **argv, int *silent)
 161 {
 162         *silent = 0;
 163
 164         /* revs->max_count == -2 means --no-index */
 165         while (1 < argc && argv[1][0] == '-') {
 166                 if (!strcmp(argv[1], "--base"))
 167                         revs->max_count = 1;
 168                 else if (!strcmp(argv[1], "--ours"))
 169                         revs->max_count = 2;
 170                 else if (!strcmp(argv[1], "--theirs"))
 171                         revs->max_count = 3;
 172                 else if (!strcmp(argv[1], "-n") ||
 173                                 !strcmp(argv[1], "--no-index"))
 174                         revs->max_count = -2;
 175                 else if (!strcmp(argv[1], "-q"))
 176                         *silent = 1;
 177                 else
 178                         return error("invalid option: %s", argv[1]);
 179                 argv++; argc--;
 180         }
 181
 182         if (revs->max_count == -1 && revs->diffopt.nr_paths == 2) {
 183                 /*
 184                  * If two files are specified, and at least one is untracked,
 185                  * default to no-index.
 186                  */
 187                 read_cache();
 188                 if (!is_in_index(revs->diffopt.paths[0]) ||
 189                                         !is_in_index(revs->diffopt.paths[1]))
 190                         revs->max_count = -2;
 191         }
 192
 193         /*
 194          * Make sure there are NO revision (i.e. pending object) parameter,
 195          * rev.max_count is reasonable (0 <= n <= 3),
 196          * there is no other revision filtering parameters.
 197          */
 198         if (revs->pending.nr || revs->max_count > 3 ||
 199             revs->min_age != -1 || revs->max_age != -1)
 200                 return error("no revision allowed with diff-files");
 201
 202         if (revs->max_count == -1 &&
 203             (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
 204                 revs->combine_merges = revs->dense_combined_merges = 1;
 205
 206         return 0;
 207 }
 208
 209 static int is_outside_repo(const char *path, int nongit, const char *prefix)
 210 {
 211         int i;
 212         if (nongit || !strcmp(path, "-") || path[0] == '/')
 213                 return 1;
 214         if (prefixcmp(path, "../"))
 215                 return 0;
 216         if (!prefix)
 217                 return 1;
 218         for (i = strlen(prefix); !prefixcmp(path, "../"); ) {
 219                 while (i > 0 && prefix[i - 1] != '/')
 220                         i--;
 221                 if (--i < 0)
 222                         return 1;
 223                 path += 3;
 224         }
 225         return 0;
 226 }
 227
 228 int setup_diff_no_index(struct rev_info *revs,
 229                 int argc, const char ** argv, int nongit, const char *prefix)
 230 {
 231         int i;
 232         for (i = 1; i < argc; i++)
 233                 if (argv[i][0] != '-' || argv[i][1] == '\0')
 234                         break;
 235                 else if (!strcmp(argv[i], "--")) {
 236                         i++;
 237                         break;
 238                 } else if (i < argc - 3 && !strcmp(argv[i], "--no-index")) {
 239                         i = argc - 3;
 240                         break;
 241                 }
 242         if (argc != i + 2 || (!is_outside_repo(argv[i + 1], nongit, prefix) &&
 243                                 !is_outside_repo(argv[i], nongit, prefix)))
 244                 return -1;
 245
 246         diff_setup(&revs->diffopt);
 247         for (i = 1; i < argc - 2; )
 248                 if (!strcmp(argv[i], "--no-index"))
 249                         i++;
 250                 else {
 251                         int j = diff_opt_parse(&revs->diffopt,
 252                                         argv + i, argc - i);
 253                         if (!j)
 254                                 die("invalid diff option/value: %s", argv[i]);
 255                         i += j;
 256                 }
 257
 258         if (prefix) {
 259                 int len = strlen(prefix);
 260
 261                 revs->diffopt.paths = xcalloc(2, sizeof(char*));
 262                 for (i = 0; i < 2; i++) {
 263                         const char *p = argv[argc - 2 + i];
 264                         /*
 265                          * stdin should be spelled as '-'; if you have
 266                          * path that is '-', spell it as ./-.
 267                          */
 268                         p = (strcmp(p, "-")
 269                              ? xstrdup(prefix_filename(prefix, len, p))
 270                              : p);
 271                         revs->diffopt.paths[i] = p;
 272                 }
 273         }
 274         else
 275                 revs->diffopt.paths = argv + argc - 2;
 276         revs->diffopt.nr_paths = 2;
 277         revs->max_count = -2;
 278         return 0;
 279 }
 280
 281 int run_diff_files_cmd(struct rev_info *revs, int argc, const char **argv)
 282 {
 283         int silent_on_removed;
 284
 285         if (handle_diff_files_args(revs, argc, argv, &silent_on_removed))
 286                 return -1;
 287
 288         if (revs->max_count == -2) {
 289                 if (revs->diffopt.nr_paths != 2)
 290                         return error("need two files/directories with --no-index");
 291                 if (queue_diff(&revs->diffopt, revs->diffopt.paths[0],
 292                                 revs->diffopt.paths[1]))
 293                         return -1;
 294                 diffcore_std(&revs->diffopt);
 295                 diff_flush(&revs->diffopt);
 296                 /*
 297                  * The return code for --no-index imitates diff(1):
 298                  * 0 = no changes, 1 = changes, else error
 299                  */
 300                 return revs->diffopt.found_changes;
 301         }
 302
 303         if (read_cache() < 0) {
 304                 perror("read_cache");
 305                 return -1;
 306         }
 307         return run_diff_files(revs, silent_on_removed);
 308 }
 309
 310 int run_diff_files(struct rev_info *revs, int silent_on_removed)
 311 {
 312         int entries, i;
 313         int diff_unmerged_stage = revs->max_count;
 314
 315         if (diff_unmerged_stage < 0)
 316                 diff_unmerged_stage = 2;
 317         entries = active_nr;
 318         for (i = 0; i < entries; i++) {
 319                 struct stat st;
 320                 unsigned int oldmode, newmode;
 321                 struct cache_entry *ce = active_cache[i];
 322                 int changed;
 323
 324                 if (!ce_path_match(ce, revs->prune_data))
 325                         continue;
 326
 327                 if (ce_stage(ce)) {
 328                         struct combine_diff_path *dpath;
 329                         int num_compare_stages = 0;
 330                         size_t path_len;
 331
 332                         path_len = ce_namelen(ce);
 333
 334                         dpath = xmalloc(combine_diff_path_size(5, path_len));
 335                         dpath->path = (char *) &(dpath->parent[5]);
 336
 337                         dpath->next = NULL;
 338                         dpath->len = path_len;
 339                         memcpy(dpath->path, ce->name, path_len);
 340                         dpath->path[path_len] = '\0';
 341                         hashclr(dpath->sha1);
 342                         memset(&(dpath->parent[0]), 0,
 343                                sizeof(struct combine_diff_parent)*5);
 344
 345                         if (lstat(ce->name, &st) < 0) {
 346                                 if (errno != ENOENT && errno != ENOTDIR) {
 347                                         perror(ce->name);
 348                                         continue;
 349                                 }
 350                                 if (silent_on_removed)
 351                                         continue;
 352                         }
 353                         else
 354                                 dpath->mode = canon_mode(st.st_mode);
 355
 356                         while (i < entries) {
 357                                 struct cache_entry *nce = active_cache[i];
 358                                 int stage;
 359
 360                                 if (strcmp(ce->name, nce->name))
 361                                         break;
 362
 363                                 /* Stage #2 (ours) is the first parent,
 364                                  * stage #3 (theirs) is the second.
 365                                  */
 366                                 stage = ce_stage(nce);
 367                                 if (2 <= stage) {
 368                                         int mode = ntohl(nce->ce_mode);
 369                                         num_compare_stages++;
 370                                         hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
 371                                         dpath->parent[stage-2].mode =
 372                                                 canon_mode(mode);
 373                                         dpath->parent[stage-2].status =
 374                                                 DIFF_STATUS_MODIFIED;
 375                                 }
 376
 377                                 /* diff against the proper unmerged stage */
 378                                 if (stage == diff_unmerged_stage)
 379                                         ce = nce;
 380                                 i++;
 381                         }
 382                         /*
 383                          * Compensate for loop update
 384                          */
 385                         i--;
 386
 387                         if (revs->combine_merges && num_compare_stages == 2) {
 388                                 show_combined_diff(dpath, 2,
 389                                                    revs->dense_combined_merges,
 390                                                    revs);
 391                                 free(dpath);
 392                                 continue;
 393                         }
 394                         free(dpath);
 395                         dpath = NULL;
 396
 397                         /*
 398                          * Show the diff for the 'ce' if we found the one
 399                          * from the desired stage.
 400                          */
 401                         diff_unmerge(&revs->diffopt, ce->name, 0, null_sha1);
 402                         if (ce_stage(ce) != diff_unmerged_stage)
 403                                 continue;
 404                 }
 405
 406                 if (lstat(ce->name, &st) < 0) {
 407                         if (errno != ENOENT && errno != ENOTDIR) {
 408                                 perror(ce->name);
 409                                 continue;
 410                         }
 411                         if (silent_on_removed)
 412                                 continue;
 413                         diff_addremove(&revs->diffopt, '-', ntohl(ce->ce_mode),
 414                                        ce->sha1, ce->name, NULL);
 415                         continue;
 416                 }
 417                 changed = ce_match_stat(ce, &st, 0);
 418                 if (!changed && !revs->diffopt.find_copies_harder)
 419                         continue;
 420                 oldmode = ntohl(ce->ce_mode);
 421
 422                 newmode = canon_mode(st.st_mode);
 423                 if (!trust_executable_bit &&
 424                     S_ISREG(newmode) && S_ISREG(oldmode) &&
 425                     ((newmode ^ oldmode) == 0111))
 426                         newmode = oldmode;
 427                 diff_change(&revs->diffopt, oldmode, newmode,
 428                             ce->sha1, (changed ? null_sha1 : ce->sha1),
 429                             ce->name, NULL);
 430
 431         }
 432         diffcore_std(&revs->diffopt);
 433         diff_flush(&revs->diffopt);
 434         return 0;
 435 }
 436
 437 /*
 438  * diff-index
 439  */
 440
 441 /* A file entry went away or appeared */
 442 static void diff_index_show_file(struct rev_info *revs,
 443                                  const char *prefix,
 444                                  struct cache_entry *ce,
 445                                  unsigned char *sha1, unsigned int mode)
 446 {
 447         diff_addremove(&revs->diffopt, prefix[0], ntohl(mode),
 448                        sha1, ce->name, NULL);
 449 }
 450
 451 static int get_stat_data(struct cache_entry *ce,
 452                          unsigned char **sha1p,
 453                          unsigned int *modep,
 454                          int cached, int match_missing)
 455 {
 456         unsigned char *sha1 = ce->sha1;
 457         unsigned int mode = ce->ce_mode;
 458
 459         if (!cached) {
 460                 static unsigned char no_sha1[20];
 461                 int changed;
 462                 struct stat st;
 463                 if (lstat(ce->name, &st) < 0) {
 464                         if (errno == ENOENT && match_missing) {
 465                                 *sha1p = sha1;
 466                                 *modep = mode;
 467                                 return 0;
 468                         }
 469                         return -1;
 470                 }
 471                 changed = ce_match_stat(ce, &st, 0);
 472                 if (changed) {
 473                         mode = ce_mode_from_stat(ce, st.st_mode);
 474                         sha1 = no_sha1;
 475                 }
 476         }
 477
 478         *sha1p = sha1;
 479         *modep = mode;
 480         return 0;
 481 }
 482
 483 static void show_new_file(struct rev_info *revs,
 484                           struct cache_entry *new,
 485                           int cached, int match_missing)
 486 {
 487         unsigned char *sha1;
 488         unsigned int mode;
 489
 490         /* New file in the index: it might actually be different in
 491          * the working copy.
 492          */
 493         if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0)
 494                 return;
 495
 496         diff_index_show_file(revs, "+", new, sha1, mode);
 497 }
 498
 499 static int show_modified(struct rev_info *revs,
 500                          struct cache_entry *old,
 501                          struct cache_entry *new,
 502                          int report_missing,
 503                          int cached, int match_missing)
 504 {
 505         unsigned int mode, oldmode;
 506         unsigned char *sha1;
 507
 508         if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0) {
 509                 if (report_missing)
 510                         diff_index_show_file(revs, "-", old,
 511                                              old->sha1, old->ce_mode);
 512                 return -1;
 513         }
 514
 515         if (revs->combine_merges && !cached &&
 516             (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
 517                 struct combine_diff_path *p;
 518                 int pathlen = ce_namelen(new);
 519
 520                 p = xmalloc(combine_diff_path_size(2, pathlen));
 521                 p->path = (char *) &p->parent[2];
 522                 p->next = NULL;
 523                 p->len = pathlen;
 524                 memcpy(p->path, new->name, pathlen);
 525                 p->path[pathlen] = 0;
 526                 p->mode = ntohl(mode);
 527                 hashclr(p->sha1);
 528                 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
 529                 p->parent[0].status = DIFF_STATUS_MODIFIED;
 530                 p->parent[0].mode = ntohl(new->ce_mode);
 531                 hashcpy(p->parent[0].sha1, new->sha1);
 532                 p->parent[1].status = DIFF_STATUS_MODIFIED;
 533                 p->parent[1].mode = ntohl(old->ce_mode);
 534                 hashcpy(p->parent[1].sha1, old->sha1);
 535                 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
 536                 free(p);
 537                 return 0;
 538         }
 539
 540         oldmode = old->ce_mode;
 541         if (mode == oldmode && !hashcmp(sha1, old->sha1) &&
 542             !revs->diffopt.find_copies_harder)
 543                 return 0;
 544
 545         mode = ntohl(mode);
 546         oldmode = ntohl(oldmode);
 547
 548         diff_change(&revs->diffopt, oldmode, mode,
 549                     old->sha1, sha1, old->name, NULL);
 550         return 0;
 551 }
 552
 553 static int diff_cache(struct rev_info *revs,
 554                       struct cache_entry **ac, int entries,
 555                       const char **pathspec,
 556                       int cached, int match_missing)
 557 {
 558         while (entries) {
 559                 struct cache_entry *ce = *ac;
 560                 int same = (entries > 1) && ce_same_name(ce, ac[1]);
 561
 562                 if (!ce_path_match(ce, pathspec))
 563                         goto skip_entry;
 564
 565                 switch (ce_stage(ce)) {
 566                 case 0:
 567                         /* No stage 1 entry? That means it's a new file */
 568                         if (!same) {
 569                                 show_new_file(revs, ce, cached, match_missing);
 570                                 break;
 571                         }
 572                         /* Show difference between old and new */
 573                         show_modified(revs, ac[1], ce, 1,
 574                                       cached, match_missing);
 575                         break;
 576                 case 1:
 577                         /* No stage 3 (merge) entry?
 578                          * That means it's been deleted.
 579                          */
 580                         if (!same) {
 581                                 diff_index_show_file(revs, "-", ce,
 582                                                      ce->sha1, ce->ce_mode);
 583                                 break;
 584                         }
 585                         /* We come here with ce pointing at stage 1
 586                          * (original tree) and ac[1] pointing at stage
 587                          * 3 (unmerged).  show-modified with
 588                          * report-missing set to false does not say the
 589                          * file is deleted but reports true if work
 590                          * tree does not have it, in which case we
 591                          * fall through to report the unmerged state.
 592                          * Otherwise, we show the differences between
 593                          * the original tree and the work tree.
 594                          */
 595                         if (!cached &&
 596                             !show_modified(revs, ce, ac[1], 0,
 597                                            cached, match_missing))
 598                                 break;
 599                         diff_unmerge(&revs->diffopt, ce->name,
 600                                      ntohl(ce->ce_mode), ce->sha1);
 601                         break;
 602                 case 3:
 603                         diff_unmerge(&revs->diffopt, ce->name,
 604                                      0, null_sha1);
 605                         break;
 606
 607                 default:
 608                         die("impossible cache entry stage");
 609                 }
 610
 611 skip_entry:
 612                 /*
 613                  * Ignore all the different stages for this file,
 614                  * we've handled the relevant cases now.
 615                  */
 616                 do {
 617                         ac++;
 618                         entries--;
 619                 } while (entries && ce_same_name(ce, ac[0]));
 620         }
 621         return 0;
 622 }
 623
 624 /*
 625  * This turns all merge entries into "stage 3". That guarantees that
 626  * when we read in the new tree (into "stage 1"), we won't lose sight
 627  * of the fact that we had unmerged entries.
 628  */
 629 static void mark_merge_entries(void)
 630 {
 631         int i;
 632         for (i = 0; i < active_nr; i++) {
 633                 struct cache_entry *ce = active_cache[i];
 634                 if (!ce_stage(ce))
 635                         continue;
 636                 ce->ce_flags |= htons(CE_STAGEMASK);
 637         }
 638 }
 639
 640 int run_diff_index(struct rev_info *revs, int cached)
 641 {
 642         int ret;
 643         struct object *ent;
 644         struct tree *tree;
 645         const char *tree_name;
 646         int match_missing = 0;
 647
 648         /*
 649          * Backward compatibility wart - "diff-index -m" does
 650          * not mean "do not ignore merges", but totally different.
 651          */
 652         if (!revs->ignore_merges)
 653                 match_missing = 1;
 654
 655         mark_merge_entries();
 656
 657         ent = revs->pending.objects[0].item;
 658         tree_name = revs->pending.objects[0].name;
 659         tree = parse_tree_indirect(ent->sha1);
 660         if (!tree)
 661                 return error("bad tree object %s", tree_name);
 662         if (read_tree(tree, 1, revs->prune_data))
 663                 return error("unable to read tree object %s", tree_name);
 664         ret = diff_cache(revs, active_cache, active_nr, revs->prune_data,
 665                          cached, match_missing);
 666         diffcore_std(&revs->diffopt);
 667         diff_flush(&revs->diffopt);
 668         return ret;
 669 }
 670
 671 int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
 672 {
 673         struct tree *tree;
 674         struct rev_info revs;
 675         int i;
 676         struct cache_entry **dst;
 677         struct cache_entry *last = NULL;
 678
 679         /*
 680          * This is used by git-blame to run diff-cache internally;
 681          * it potentially needs to repeatedly run this, so we will
 682          * start by removing the higher order entries the last round
 683          * left behind.
 684          */
 685         dst = active_cache;
 686         for (i = 0; i < active_nr; i++) {
 687                 struct cache_entry *ce = active_cache[i];
 688                 if (ce_stage(ce)) {
 689                         if (last && !strcmp(ce->name, last->name))
 690                                 continue;
 691                         cache_tree_invalidate_path(active_cache_tree,
 692                                                    ce->name);
 693                         last = ce;
 694                         ce->ce_mode = 0;
 695                         ce->ce_flags &= ~htons(CE_STAGEMASK);
 696                 }
 697                 *dst++ = ce;
 698         }
 699         active_nr = dst - active_cache;
 700
 701         init_revisions(&revs, NULL);
 702         revs.prune_data = opt->paths;
 703         tree = parse_tree_indirect(tree_sha1);
 704         if (!tree)
 705                 die("bad tree object %s", sha1_to_hex(tree_sha1));
 706         if (read_tree(tree, 1, opt->paths))
 707                 return error("unable to read tree %s", sha1_to_hex(tree_sha1));
 708         return diff_cache(&revs, active_cache, active_nr, revs.prune_data,
 709                           1, 0);
 710 }