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