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 static int is_outside_repo(const char *path, int nongit, const char *prefix)
 204 {
 205         int i;
 206         if (nongit || !strcmp(path, "-") || path[0] == '/')
 207                 return 1;
 208         if (prefixcmp(path, "../"))
 209                 return 0;
 210         if (!prefix)
 211                 return 1;
 212         for (i = strlen(prefix); !prefixcmp(path, "../"); ) {
 213                 while (i > 0 && prefix[i - 1] != '/')
 214                         i--;
 215                 if (--i < 0)
 216                         return 1;
 217                 path += 3;
 218         }
 219         return 0;
 220 }
 221
 222 int setup_diff_no_index(struct rev_info *revs,
 223                 int argc, const char ** argv, int nongit, const char *prefix)
 224 {
 225         int i;
 226         for (i = 1; i < argc; i++)
 227                 if (argv[i][0] != '-')
 228                         break;
 229                 else if (!strcmp(argv[i], "--")) {
 230                         i++;
 231                         break;
 232                 } else if (i < argc - 3 && !strcmp(argv[i], "--no-index")) {
 233                         i = argc - 3;
 234                         break;
 235                 }
 236         if (argc != i + 2 || (!is_outside_repo(argv[i + 1], nongit, prefix) &&
 237                                 !is_outside_repo(argv[i], nongit, prefix)))
 238                 return -1;
 239
 240         diff_setup(&revs->diffopt);
 241         for (i = 1; i < argc - 2; )
 242                 if (!strcmp(argv[i], "--no-index"))
 243                         i++;
 244                 else {
 245                         int j = diff_opt_parse(&revs->diffopt,
 246                                         argv + i, argc - i);
 247                         if (!j)
 248                                 die("invalid diff option/value: %s", argv[i]);
 249                         i += j;
 250                 }
 251         revs->diffopt.paths = argv + argc - 2;
 252         revs->diffopt.nr_paths = 2;
 253         revs->max_count = -2;
 254         return 0;
 255 }
 256
 257 int run_diff_files_cmd(struct rev_info *revs, int argc, const char **argv)
 258 {
 259         int silent_on_removed;
 260
 261         if (handle_diff_files_args(revs, argc, argv, &silent_on_removed))
 262                 return -1;
 263
 264         if (revs->max_count == -2) {
 265                 if (revs->diffopt.nr_paths != 2)
 266                         return error("need two files/directories with --no-index");
 267                 if (queue_diff(&revs->diffopt, revs->diffopt.paths[0],
 268                                 revs->diffopt.paths[1]))
 269                         return -1;
 270                 diffcore_std(&revs->diffopt);
 271                 diff_flush(&revs->diffopt);
 272                 /*
 273                  * The return code for --no-index imitates diff(1):
 274                  * 0 = no changes, 1 = changes, else error
 275                  */
 276                 return revs->diffopt.found_changes;
 277         }
 278
 279         if (read_cache() < 0) {
 280                 perror("read_cache");
 281                 return -1;
 282         }
 283         return run_diff_files(revs, silent_on_removed);
 284 }
 285
 286 int run_diff_files(struct rev_info *revs, int silent_on_removed)
 287 {
 288         int entries, i;
 289         int diff_unmerged_stage = revs->max_count;
 290
 291         if (diff_unmerged_stage < 0)
 292                 diff_unmerged_stage = 2;
 293         entries = active_nr;
 294         for (i = 0; i < entries; i++) {
 295                 struct stat st;
 296                 unsigned int oldmode, newmode;
 297                 struct cache_entry *ce = active_cache[i];
 298                 int changed;
 299
 300                 if (!ce_path_match(ce, revs->prune_data))
 301                         continue;
 302
 303                 if (ce_stage(ce)) {
 304                         struct combine_diff_path *dpath;
 305                         int num_compare_stages = 0;
 306                         size_t path_len;
 307
 308                         path_len = ce_namelen(ce);
 309
 310                         dpath = xmalloc(combine_diff_path_size(5, path_len));
 311                         dpath->path = (char *) &(dpath->parent[5]);
 312
 313                         dpath->next = NULL;
 314                         dpath->len = path_len;
 315                         memcpy(dpath->path, ce->name, path_len);
 316                         dpath->path[path_len] = '\0';
 317                         hashclr(dpath->sha1);
 318                         memset(&(dpath->parent[0]), 0,
 319                                sizeof(struct combine_diff_parent)*5);
 320
 321                         if (lstat(ce->name, &st) < 0) {
 322                                 if (errno != ENOENT && errno != ENOTDIR) {
 323                                         perror(ce->name);
 324                                         continue;
 325                                 }
 326                                 if (silent_on_removed)
 327                                         continue;
 328                         }
 329                         else
 330                                 dpath->mode = canon_mode(st.st_mode);
 331
 332                         while (i < entries) {
 333                                 struct cache_entry *nce = active_cache[i];
 334                                 int stage;
 335
 336                                 if (strcmp(ce->name, nce->name))
 337                                         break;
 338
 339                                 /* Stage #2 (ours) is the first parent,
 340                                  * stage #3 (theirs) is the second.
 341                                  */
 342                                 stage = ce_stage(nce);
 343                                 if (2 <= stage) {
 344                                         int mode = ntohl(nce->ce_mode);
 345                                         num_compare_stages++;
 346                                         hashcpy(dpath->parent[stage-2].sha1, nce->sha1);
 347                                         dpath->parent[stage-2].mode =
 348                                                 canon_mode(mode);
 349                                         dpath->parent[stage-2].status =
 350                                                 DIFF_STATUS_MODIFIED;
 351                                 }
 352
 353                                 /* diff against the proper unmerged stage */
 354                                 if (stage == diff_unmerged_stage)
 355                                         ce = nce;
 356                                 i++;
 357                         }
 358                         /*
 359                          * Compensate for loop update
 360                          */
 361                         i--;
 362
 363                         if (revs->combine_merges && num_compare_stages == 2) {
 364                                 show_combined_diff(dpath, 2,
 365                                                    revs->dense_combined_merges,
 366                                                    revs);
 367                                 free(dpath);
 368                                 continue;
 369                         }
 370                         free(dpath);
 371                         dpath = NULL;
 372
 373                         /*
 374                          * Show the diff for the 'ce' if we found the one
 375                          * from the desired stage.
 376                          */
 377                         diff_unmerge(&revs->diffopt, ce->name, 0, null_sha1);
 378                         if (ce_stage(ce) != diff_unmerged_stage)
 379                                 continue;
 380                 }
 381
 382                 if (lstat(ce->name, &st) < 0) {
 383                         if (errno != ENOENT && errno != ENOTDIR) {
 384                                 perror(ce->name);
 385                                 continue;
 386                         }
 387                         if (silent_on_removed)
 388                                 continue;
 389                         diff_addremove(&revs->diffopt, '-', ntohl(ce->ce_mode),
 390                                        ce->sha1, ce->name, NULL);
 391                         continue;
 392                 }
 393                 changed = ce_match_stat(ce, &st, 0);
 394                 if (!changed && !revs->diffopt.find_copies_harder)
 395                         continue;
 396                 oldmode = ntohl(ce->ce_mode);
 397
 398                 newmode = canon_mode(st.st_mode);
 399                 if (!trust_executable_bit &&
 400                     S_ISREG(newmode) && S_ISREG(oldmode) &&
 401                     ((newmode ^ oldmode) == 0111))
 402                         newmode = oldmode;
 403                 diff_change(&revs->diffopt, oldmode, newmode,
 404                             ce->sha1, (changed ? null_sha1 : ce->sha1),
 405                             ce->name, NULL);
 406
 407         }
 408         diffcore_std(&revs->diffopt);
 409         diff_flush(&revs->diffopt);
 410         return 0;
 411 }
 412
 413 /*
 414  * diff-index
 415  */
 416
 417 /* A file entry went away or appeared */
 418 static void diff_index_show_file(struct rev_info *revs,
 419                                  const char *prefix,
 420                                  struct cache_entry *ce,
 421                                  unsigned char *sha1, unsigned int mode)
 422 {
 423         diff_addremove(&revs->diffopt, prefix[0], ntohl(mode),
 424                        sha1, ce->name, NULL);
 425 }
 426
 427 static int get_stat_data(struct cache_entry *ce,
 428                          unsigned char **sha1p,
 429                          unsigned int *modep,
 430                          int cached, int match_missing)
 431 {
 432         unsigned char *sha1 = ce->sha1;
 433         unsigned int mode = ce->ce_mode;
 434
 435         if (!cached) {
 436                 static unsigned char no_sha1[20];
 437                 int changed;
 438                 struct stat st;
 439                 if (lstat(ce->name, &st) < 0) {
 440                         if (errno == ENOENT && match_missing) {
 441                                 *sha1p = sha1;
 442                                 *modep = mode;
 443                                 return 0;
 444                         }
 445                         return -1;
 446                 }
 447                 changed = ce_match_stat(ce, &st, 0);
 448                 if (changed) {
 449                         mode = ce_mode_from_stat(ce, st.st_mode);
 450                         sha1 = no_sha1;
 451                 }
 452         }
 453
 454         *sha1p = sha1;
 455         *modep = mode;
 456         return 0;
 457 }
 458
 459 static void show_new_file(struct rev_info *revs,
 460                           struct cache_entry *new,
 461                           int cached, int match_missing)
 462 {
 463         unsigned char *sha1;
 464         unsigned int mode;
 465
 466         /* New file in the index: it might actually be different in
 467          * the working copy.
 468          */
 469         if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0)
 470                 return;
 471
 472         diff_index_show_file(revs, "+", new, sha1, mode);
 473 }
 474
 475 static int show_modified(struct rev_info *revs,
 476                          struct cache_entry *old,
 477                          struct cache_entry *new,
 478                          int report_missing,
 479                          int cached, int match_missing)
 480 {
 481         unsigned int mode, oldmode;
 482         unsigned char *sha1;
 483
 484         if (get_stat_data(new, &sha1, &mode, cached, match_missing) < 0) {
 485                 if (report_missing)
 486                         diff_index_show_file(revs, "-", old,
 487                                              old->sha1, old->ce_mode);
 488                 return -1;
 489         }
 490
 491         if (revs->combine_merges && !cached &&
 492             (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
 493                 struct combine_diff_path *p;
 494                 int pathlen = ce_namelen(new);
 495
 496                 p = xmalloc(combine_diff_path_size(2, pathlen));
 497                 p->path = (char *) &p->parent[2];
 498                 p->next = NULL;
 499                 p->len = pathlen;
 500                 memcpy(p->path, new->name, pathlen);
 501                 p->path[pathlen] = 0;
 502                 p->mode = ntohl(mode);
 503                 hashclr(p->sha1);
 504                 memset(p->parent, 0, 2 * sizeof(struct combine_diff_parent));
 505                 p->parent[0].status = DIFF_STATUS_MODIFIED;
 506                 p->parent[0].mode = ntohl(new->ce_mode);
 507                 hashcpy(p->parent[0].sha1, new->sha1);
 508                 p->parent[1].status = DIFF_STATUS_MODIFIED;
 509                 p->parent[1].mode = ntohl(old->ce_mode);
 510                 hashcpy(p->parent[1].sha1, old->sha1);
 511                 show_combined_diff(p, 2, revs->dense_combined_merges, revs);
 512                 free(p);
 513                 return 0;
 514         }
 515
 516         oldmode = old->ce_mode;
 517         if (mode == oldmode && !hashcmp(sha1, old->sha1) &&
 518             !revs->diffopt.find_copies_harder)
 519                 return 0;
 520
 521         mode = ntohl(mode);
 522         oldmode = ntohl(oldmode);
 523
 524         diff_change(&revs->diffopt, oldmode, mode,
 525                     old->sha1, sha1, old->name, NULL);
 526         return 0;
 527 }
 528
 529 static int diff_cache(struct rev_info *revs,
 530                       struct cache_entry **ac, int entries,
 531                       const char **pathspec,
 532                       int cached, int match_missing)
 533 {
 534         while (entries) {
 535                 struct cache_entry *ce = *ac;
 536                 int same = (entries > 1) && ce_same_name(ce, ac[1]);
 537
 538                 if (!ce_path_match(ce, pathspec))
 539                         goto skip_entry;
 540
 541                 switch (ce_stage(ce)) {
 542                 case 0:
 543                         /* No stage 1 entry? That means it's a new file */
 544                         if (!same) {
 545                                 show_new_file(revs, ce, cached, match_missing);
 546                                 break;
 547                         }
 548                         /* Show difference between old and new */
 549                         show_modified(revs, ac[1], ce, 1,
 550                                       cached, match_missing);
 551                         break;
 552                 case 1:
 553                         /* No stage 3 (merge) entry?
 554                          * That means it's been deleted.
 555                          */
 556                         if (!same) {
 557                                 diff_index_show_file(revs, "-", ce,
 558                                                      ce->sha1, ce->ce_mode);
 559                                 break;
 560                         }
 561                         /* We come here with ce pointing at stage 1
 562                          * (original tree) and ac[1] pointing at stage
 563                          * 3 (unmerged).  show-modified with
 564                          * report-missing set to false does not say the
 565                          * file is deleted but reports true if work
 566                          * tree does not have it, in which case we
 567                          * fall through to report the unmerged state.
 568                          * Otherwise, we show the differences between
 569                          * the original tree and the work tree.
 570                          */
 571                         if (!cached &&
 572                             !show_modified(revs, ce, ac[1], 0,
 573                                            cached, match_missing))
 574                                 break;
 575                         diff_unmerge(&revs->diffopt, ce->name,
 576                                      ntohl(ce->ce_mode), ce->sha1);
 577                         break;
 578                 case 3:
 579                         diff_unmerge(&revs->diffopt, ce->name,
 580                                      0, null_sha1);
 581                         break;
 582
 583                 default:
 584                         die("impossible cache entry stage");
 585                 }
 586
 587 skip_entry:
 588                 /*
 589                  * Ignore all the different stages for this file,
 590                  * we've handled the relevant cases now.
 591                  */
 592                 do {
 593                         ac++;
 594                         entries--;
 595                 } while (entries && ce_same_name(ce, ac[0]));
 596         }
 597         return 0;
 598 }
 599
 600 /*
 601  * This turns all merge entries into "stage 3". That guarantees that
 602  * when we read in the new tree (into "stage 1"), we won't lose sight
 603  * of the fact that we had unmerged entries.
 604  */
 605 static void mark_merge_entries(void)
 606 {
 607         int i;
 608         for (i = 0; i < active_nr; i++) {
 609                 struct cache_entry *ce = active_cache[i];
 610                 if (!ce_stage(ce))
 611                         continue;
 612                 ce->ce_flags |= htons(CE_STAGEMASK);
 613         }
 614 }
 615
 616 int run_diff_index(struct rev_info *revs, int cached)
 617 {
 618         int ret;
 619         struct object *ent;
 620         struct tree *tree;
 621         const char *tree_name;
 622         int match_missing = 0;
 623
 624         /*
 625          * Backward compatibility wart - "diff-index -m" does
 626          * not mean "do not ignore merges", but totally different.
 627          */
 628         if (!revs->ignore_merges)
 629                 match_missing = 1;
 630
 631         mark_merge_entries();
 632
 633         ent = revs->pending.objects[0].item;
 634         tree_name = revs->pending.objects[0].name;
 635         tree = parse_tree_indirect(ent->sha1);
 636         if (!tree)
 637                 return error("bad tree object %s", tree_name);
 638         if (read_tree(tree, 1, revs->prune_data))
 639                 return error("unable to read tree object %s", tree_name);
 640         ret = diff_cache(revs, active_cache, active_nr, revs->prune_data,
 641                          cached, match_missing);
 642         diffcore_std(&revs->diffopt);
 643         diff_flush(&revs->diffopt);
 644         return ret;
 645 }
 646
 647 int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
 648 {
 649         struct tree *tree;
 650         struct rev_info revs;
 651         int i;
 652         struct cache_entry **dst;
 653         struct cache_entry *last = NULL;
 654
 655         /*
 656          * This is used by git-blame to run diff-cache internally;
 657          * it potentially needs to repeatedly run this, so we will
 658          * start by removing the higher order entries the last round
 659          * left behind.
 660          */
 661         dst = active_cache;
 662         for (i = 0; i < active_nr; i++) {
 663                 struct cache_entry *ce = active_cache[i];
 664                 if (ce_stage(ce)) {
 665                         if (last && !strcmp(ce->name, last->name))
 666                                 continue;
 667                         cache_tree_invalidate_path(active_cache_tree,
 668                                                    ce->name);
 669                         last = ce;
 670                         ce->ce_mode = 0;
 671                         ce->ce_flags &= ~htons(CE_STAGEMASK);
 672                 }
 673                 *dst++ = ce;
 674         }
 675         active_nr = dst - active_cache;
 676
 677         init_revisions(&revs, NULL);
 678         revs.prune_data = opt->paths;
 679         tree = parse_tree_indirect(tree_sha1);
 680         if (!tree)
 681                 die("bad tree object %s", sha1_to_hex(tree_sha1));
 682         if (read_tree(tree, 1, opt->paths))
 683                 return error("unable to read tree %s", sha1_to_hex(tree_sha1));
 684         return diff_cache(&revs, active_cache, active_nr, revs.prune_data,
 685                           1, 0);
 686 }