revision.c

   1 #include "cache.h"
   2 #include "tag.h"
   3 #include "blob.h"
   4 #include "tree.h"
   5 #include "commit.h"
   6 #include "diff.h"
   7 #include "refs.h"
   8 #include "revision.h"
   9
  10 static char *path_name(struct name_path *path, const char *name)
  11 {
  12         struct name_path *p;
  13         char *n, *m;
  14         int nlen = strlen(name);
  15         int len = nlen + 1;
  16
  17         for (p = path; p; p = p->up) {
  18                 if (p->elem_len)
  19                         len += p->elem_len + 1;
  20         }
  21         n = xmalloc(len);
  22         m = n + len - (nlen + 1);
  23         strcpy(m, name);
  24         for (p = path; p; p = p->up) {
  25                 if (p->elem_len) {
  26                         m -= p->elem_len + 1;
  27                         memcpy(m, p->elem, p->elem_len);
  28                         m[p->elem_len] = '/';
  29                 }
  30         }
  31         return n;
  32 }
  33
  34 struct object_list **add_object(struct object *obj,
  35                                        struct object_list **p,
  36                                        struct name_path *path,
  37                                        const char *name)
  38 {
  39         struct object_list *entry = xmalloc(sizeof(*entry));
  40         entry->item = obj;
  41         entry->next = *p;
  42         entry->name = path_name(path, name);
  43         *p = entry;
  44         return &entry->next;
  45 }
  46
  47 static void mark_blob_uninteresting(struct blob *blob)
  48 {
  49         if (blob->object.flags & UNINTERESTING)
  50                 return;
  51         blob->object.flags |= UNINTERESTING;
  52 }
  53
  54 void mark_tree_uninteresting(struct tree *tree)
  55 {
  56         struct object *obj = &tree->object;
  57         struct tree_entry_list *entry;
  58
  59         if (obj->flags & UNINTERESTING)
  60                 return;
  61         obj->flags |= UNINTERESTING;
  62         if (!has_sha1_file(obj->sha1))
  63                 return;
  64         if (parse_tree(tree) < 0)
  65                 die("bad tree %s", sha1_to_hex(obj->sha1));
  66         entry = tree->entries;
  67         tree->entries = NULL;
  68         while (entry) {
  69                 struct tree_entry_list *next = entry->next;
  70                 if (entry->directory)
  71                         mark_tree_uninteresting(entry->item.tree);
  72                 else
  73                         mark_blob_uninteresting(entry->item.blob);
  74                 free(entry);
  75                 entry = next;
  76         }
  77 }
  78
  79 void mark_parents_uninteresting(struct commit *commit)
  80 {
  81         struct commit_list *parents = commit->parents;
  82
  83         while (parents) {
  84                 struct commit *commit = parents->item;
  85                 if (!(commit->object.flags & UNINTERESTING)) {
  86                         commit->object.flags |= UNINTERESTING;
  87
  88                         /*
  89                          * Normally we haven't parsed the parent
  90                          * yet, so we won't have a parent of a parent
  91                          * here. However, it may turn out that we've
  92                          * reached this commit some other way (where it
  93                          * wasn't uninteresting), in which case we need
  94                          * to mark its parents recursively too..
  95                          */
  96                         if (commit->parents)
  97                                 mark_parents_uninteresting(commit);
  98                 }
  99
 100                 /*
 101                  * A missing commit is ok iff its parent is marked
 102                  * uninteresting.
 103                  *
 104                  * We just mark such a thing parsed, so that when
 105                  * it is popped next time around, we won't be trying
 106                  * to parse it and get an error.
 107                  */
 108                 if (!has_sha1_file(commit->object.sha1))
 109                         commit->object.parsed = 1;
 110                 parents = parents->next;
 111         }
 112 }
 113
 114 static void add_pending_object(struct rev_info *revs, struct object *obj, const char *name)
 115 {
 116         add_object(obj, &revs->pending_objects, NULL, name);
 117 }
 118
 119 static struct commit *get_commit_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
 120 {
 121         struct object *object;
 122
 123         object = parse_object(sha1);
 124         if (!object)
 125                 die("bad object %s", name);
 126
 127         /*
 128          * Tag object? Look what it points to..
 129          */
 130         while (object->type == tag_type) {
 131                 struct tag *tag = (struct tag *) object;
 132                 object->flags |= flags;
 133                 if (revs->tag_objects && !(object->flags & UNINTERESTING))
 134                         add_pending_object(revs, object, tag->tag);
 135                 object = parse_object(tag->tagged->sha1);
 136                 if (!object)
 137                         die("bad object %s", sha1_to_hex(tag->tagged->sha1));
 138         }
 139
 140         /*
 141          * Commit object? Just return it, we'll do all the complex
 142          * reachability crud.
 143          */
 144         if (object->type == commit_type) {
 145                 struct commit *commit = (struct commit *)object;
 146                 object->flags |= flags;
 147                 if (parse_commit(commit) < 0)
 148                         die("unable to parse commit %s", name);
 149                 if (flags & UNINTERESTING) {
 150                         mark_parents_uninteresting(commit);
 151                         revs->limited = 1;
 152                 }
 153                 return commit;
 154         }
 155
 156         /*
 157          * Tree object? Either mark it uniniteresting, or add it
 158          * to the list of objects to look at later..
 159          */
 160         if (object->type == tree_type) {
 161                 struct tree *tree = (struct tree *)object;
 162                 if (!revs->tree_objects)
 163                         return NULL;
 164                 if (flags & UNINTERESTING) {
 165                         mark_tree_uninteresting(tree);
 166                         return NULL;
 167                 }
 168                 add_pending_object(revs, object, "");
 169                 return NULL;
 170         }
 171
 172         /*
 173          * Blob object? You know the drill by now..
 174          */
 175         if (object->type == blob_type) {
 176                 struct blob *blob = (struct blob *)object;
 177                 if (!revs->blob_objects)
 178                         return NULL;
 179                 if (flags & UNINTERESTING) {
 180                         mark_blob_uninteresting(blob);
 181                         return NULL;
 182                 }
 183                 add_pending_object(revs, object, "");
 184                 return NULL;
 185         }
 186         die("%s is unknown object", name);
 187 }
 188
 189 static int everybody_uninteresting(struct commit_list *orig)
 190 {
 191         struct commit_list *list = orig;
 192         while (list) {
 193                 struct commit *commit = list->item;
 194                 list = list->next;
 195                 if (commit->object.flags & UNINTERESTING)
 196                         continue;
 197                 return 0;
 198         }
 199         return 1;
 200 }
 201
 202 #define TREE_SAME       0
 203 #define TREE_NEW        1
 204 #define TREE_DIFFERENT  2
 205 static int tree_difference = TREE_SAME;
 206
 207 static void file_add_remove(struct diff_options *options,
 208                     int addremove, unsigned mode,
 209                     const unsigned char *sha1,
 210                     const char *base, const char *path)
 211 {
 212         int diff = TREE_DIFFERENT;
 213
 214         /*
 215          * Is it an add of a new file? It means that
 216          * the old tree didn't have it at all, so we
 217          * will turn "TREE_SAME" -> "TREE_NEW", but
 218          * leave any "TREE_DIFFERENT" alone (and if
 219          * it already was "TREE_NEW", we'll keep it
 220          * "TREE_NEW" of course).
 221          */
 222         if (addremove == '+') {
 223                 diff = tree_difference;
 224                 if (diff != TREE_SAME)
 225                         return;
 226                 diff = TREE_NEW;
 227         }
 228         tree_difference = diff;
 229 }
 230
 231 static void file_change(struct diff_options *options,
 232                  unsigned old_mode, unsigned new_mode,
 233                  const unsigned char *old_sha1,
 234                  const unsigned char *new_sha1,
 235                  const char *base, const char *path)
 236 {
 237         tree_difference = TREE_DIFFERENT;
 238 }
 239
 240 static struct diff_options diff_opt = {
 241         .recursive = 1,
 242         .add_remove = file_add_remove,
 243         .change = file_change,
 244 };
 245
 246 static int compare_tree(struct tree *t1, struct tree *t2)
 247 {
 248         if (!t1)
 249                 return TREE_NEW;
 250         if (!t2)
 251                 return TREE_DIFFERENT;
 252         tree_difference = TREE_SAME;
 253         if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "", &diff_opt) < 0)
 254                 return TREE_DIFFERENT;
 255         return tree_difference;
 256 }
 257
 258 static int same_tree_as_empty(struct tree *t1)
 259 {
 260         int retval;
 261         void *tree;
 262         struct tree_desc empty, real;
 263
 264         if (!t1)
 265                 return 0;
 266
 267         tree = read_object_with_reference(t1->object.sha1, "tree", &real.size, NULL);
 268         if (!tree)
 269                 return 0;
 270         real.buf = tree;
 271
 272         empty.buf = "";
 273         empty.size = 0;
 274
 275         tree_difference = 0;
 276         retval = diff_tree(&empty, &real, "", &diff_opt);
 277         free(tree);
 278
 279         return retval >= 0 && !tree_difference;
 280 }
 281
 282 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 283 {
 284         struct commit_list **pp, *parent;
 285
 286         if (!commit->tree)
 287                 return;
 288
 289         if (!commit->parents) {
 290                 if (!same_tree_as_empty(commit->tree))
 291                         commit->object.flags |= TREECHANGE;
 292                 return;
 293         }
 294
 295         pp = &commit->parents;
 296         while ((parent = *pp) != NULL) {
 297                 struct commit *p = parent->item;
 298
 299                 if (p->object.flags & UNINTERESTING) {
 300                         pp = &parent->next;
 301                         continue;
 302                 }
 303
 304                 parse_commit(p);
 305                 switch (compare_tree(p->tree, commit->tree)) {
 306                 case TREE_SAME:
 307                         parent->next = NULL;
 308                         commit->parents = parent;
 309                         return;
 310
 311                 case TREE_NEW:
 312                         if (revs->remove_empty_trees && same_tree_as_empty(p->tree)) {
 313                                 *pp = parent->next;
 314                                 continue;
 315                         }
 316                 /* fallthrough */
 317                 case TREE_DIFFERENT:
 318                         pp = &parent->next;
 319                         continue;
 320                 }
 321                 die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
 322         }
 323         commit->object.flags |= TREECHANGE;
 324 }
 325
 326 static void add_parents_to_list(struct rev_info *revs, struct commit *commit, struct commit_list **list)
 327 {
 328         struct commit_list *parent = commit->parents;
 329
 330         /*
 331          * If the commit is uninteresting, don't try to
 332          * prune parents - we want the maximal uninteresting
 333          * set.
 334          *
 335          * Normally we haven't parsed the parent
 336          * yet, so we won't have a parent of a parent
 337          * here. However, it may turn out that we've
 338          * reached this commit some other way (where it
 339          * wasn't uninteresting), in which case we need
 340          * to mark its parents recursively too..
 341          */
 342         if (commit->object.flags & UNINTERESTING) {
 343                 while (parent) {
 344                         struct commit *p = parent->item;
 345                         parent = parent->next;
 346                         parse_commit(p);
 347                         p->object.flags |= UNINTERESTING;
 348                         if (p->parents)
 349                                 mark_parents_uninteresting(p);
 350                         if (p->object.flags & SEEN)
 351                                 continue;
 352                         p->object.flags |= SEEN;
 353                         insert_by_date(p, list);
 354                 }
 355                 return;
 356         }
 357
 358         /*
 359          * Ok, the commit wasn't uninteresting. Try to
 360          * simplify the commit history and find the parent
 361          * that has no differences in the path set if one exists.
 362          */
 363         if (revs->paths)
 364                 try_to_simplify_commit(revs, commit);
 365
 366         parent = commit->parents;
 367         while (parent) {
 368                 struct commit *p = parent->item;
 369
 370                 parent = parent->next;
 371
 372                 parse_commit(p);
 373                 if (p->object.flags & SEEN)
 374                         continue;
 375                 p->object.flags |= SEEN;
 376                 insert_by_date(p, list);
 377         }
 378 }
 379
 380 static void limit_list(struct rev_info *revs)
 381 {
 382         struct commit_list *list = revs->commits;
 383         struct commit_list *newlist = NULL;
 384         struct commit_list **p = &newlist;
 385
 386         if (revs->paths)
 387                 diff_tree_setup_paths(revs->paths);
 388
 389         while (list) {
 390                 struct commit_list *entry = list;
 391                 struct commit *commit = list->item;
 392                 struct object *obj = &commit->object;
 393
 394                 list = list->next;
 395                 free(entry);
 396
 397                 if (revs->max_age != -1 && (commit->date < revs->max_age))
 398                         obj->flags |= UNINTERESTING;
 399                 if (revs->unpacked && has_sha1_pack(obj->sha1))
 400                         obj->flags |= UNINTERESTING;
 401                 add_parents_to_list(revs, commit, &list);
 402                 if (obj->flags & UNINTERESTING) {
 403                         mark_parents_uninteresting(commit);
 404                         if (everybody_uninteresting(list))
 405                                 break;
 406                         continue;
 407                 }
 408                 if (revs->min_age != -1 && (commit->date > revs->min_age))
 409                         continue;
 410                 p = &commit_list_insert(commit, p)->next;
 411         }
 412         revs->commits = newlist;
 413 }
 414
 415 static void add_one_commit(struct commit *commit, struct rev_info *revs)
 416 {
 417         if (!commit || (commit->object.flags & SEEN))
 418                 return;
 419         commit->object.flags |= SEEN;
 420         commit_list_insert(commit, &revs->commits);
 421 }
 422
 423 static int all_flags;
 424 static struct rev_info *all_revs;
 425
 426 static int handle_one_ref(const char *path, const unsigned char *sha1)
 427 {
 428         struct commit *commit = get_commit_reference(all_revs, path, sha1, all_flags);
 429         add_one_commit(commit, all_revs);
 430         return 0;
 431 }
 432
 433 static void handle_all(struct rev_info *revs, unsigned flags)
 434 {
 435         all_revs = revs;
 436         all_flags = flags;
 437         for_each_ref(handle_one_ref);
 438 }
 439
 440 /*
 441  * Parse revision information, filling in the "rev_info" structure,
 442  * and removing the used arguments from the argument list.
 443  *
 444  * Returns the number of arguments left that weren't recognized
 445  * (which are also moved to the head of the argument list)
 446  */
 447 int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
 448 {
 449         int i, flags, seen_dashdash;
 450         const char **unrecognized = argv + 1;
 451         int left = 1;
 452
 453         memset(revs, 0, sizeof(*revs));
 454         revs->lifo = 1;
 455         revs->dense = 1;
 456         revs->prefix = setup_git_directory();
 457         revs->max_age = -1;
 458         revs->min_age = -1;
 459         revs->max_count = -1;
 460
 461         /* First, search for "--" */
 462         seen_dashdash = 0;
 463         for (i = 1; i < argc; i++) {
 464                 const char *arg = argv[i];
 465                 if (strcmp(arg, "--"))
 466                         continue;
 467                 argv[i] = NULL;
 468                 argc = i;
 469                 revs->paths = get_pathspec(revs->prefix, argv + i + 1);
 470                 seen_dashdash = 1;
 471                 break;
 472         }
 473
 474         flags = 0;
 475         for (i = 1; i < argc; i++) {
 476                 struct commit *commit;
 477                 const char *arg = argv[i];
 478                 unsigned char sha1[20];
 479                 char *dotdot;
 480                 int local_flags;
 481
 482                 if (*arg == '-') {
 483                         if (!strncmp(arg, "--max-count=", 12)) {
 484                                 revs->max_count = atoi(arg + 12);
 485                                 continue;
 486                         }
 487                         /* accept -<digit>, like traditilnal "head" */
 488                         if ((*arg == '-') && isdigit(arg[1])) {
 489                                 revs->max_count = atoi(arg + 1);
 490                                 continue;
 491                         }
 492                         if (!strcmp(arg, "-n")) {
 493                                 if (argc <= i + 1)
 494                                         die("-n requires an argument");
 495                                 revs->max_count = atoi(argv[++i]);
 496                                 continue;
 497                         }
 498                         if (!strncmp(arg,"-n",2)) {
 499                                 revs->max_count = atoi(arg + 2);
 500                                 continue;
 501                         }
 502                         if (!strncmp(arg, "--max-age=", 10)) {
 503                                 revs->max_age = atoi(arg + 10);
 504                                 revs->limited = 1;
 505                                 continue;
 506                         }
 507                         if (!strncmp(arg, "--min-age=", 10)) {
 508                                 revs->min_age = atoi(arg + 10);
 509                                 revs->limited = 1;
 510                                 continue;
 511                         }
 512                         if (!strncmp(arg, "--since=", 8)) {
 513                                 revs->max_age = approxidate(arg + 8);
 514                                 revs->limited = 1;
 515                                 continue;
 516                         }
 517                         if (!strncmp(arg, "--after=", 8)) {
 518                                 revs->max_age = approxidate(arg + 8);
 519                                 revs->limited = 1;
 520                                 continue;
 521                         }
 522                         if (!strncmp(arg, "--before=", 9)) {
 523                                 revs->min_age = approxidate(arg + 9);
 524                                 revs->limited = 1;
 525                                 continue;
 526                         }
 527                         if (!strncmp(arg, "--until=", 8)) {
 528                                 revs->min_age = approxidate(arg + 8);
 529                                 revs->limited = 1;
 530                                 continue;
 531                         }
 532                         if (!strcmp(arg, "--all")) {
 533                                 handle_all(revs, flags);
 534                                 continue;
 535                         }
 536                         if (!strcmp(arg, "--not")) {
 537                                 flags ^= UNINTERESTING;
 538                                 continue;
 539                         }
 540                         if (!strcmp(arg, "--default")) {
 541                                 if (++i >= argc)
 542                                         die("bad --default argument");
 543                                 def = argv[i];
 544                                 continue;
 545                         }
 546                         if (!strcmp(arg, "--topo-order")) {
 547                                 revs->topo_order = 1;
 548                                 revs->limited = 1;
 549                                 continue;
 550                         }
 551                         if (!strcmp(arg, "--date-order")) {
 552                                 revs->lifo = 0;
 553                                 revs->topo_order = 1;
 554                                 revs->limited = 1;
 555                                 continue;
 556                         }
 557                         if (!strcmp(arg, "--dense")) {
 558                                 revs->dense = 1;
 559                                 continue;
 560                         }
 561                         if (!strcmp(arg, "--sparse")) {
 562                                 revs->dense = 0;
 563                                 continue;
 564                         }
 565                         if (!strcmp(arg, "--remove-empty")) {
 566                                 revs->remove_empty_trees = 1;
 567                                 continue;
 568                         }
 569                         if (!strncmp(arg, "--no-merges", 11)) {
 570                                 revs->no_merges = 1;
 571                                 continue;
 572                         }
 573                         if (!strcmp(arg, "--objects")) {
 574                                 revs->tag_objects = 1;
 575                                 revs->tree_objects = 1;
 576                                 revs->blob_objects = 1;
 577                                 continue;
 578                         }
 579                         if (!strcmp(arg, "--objects-edge")) {
 580                                 revs->tag_objects = 1;
 581                                 revs->tree_objects = 1;
 582                                 revs->blob_objects = 1;
 583                                 revs->edge_hint = 1;
 584                                 continue;
 585                         }
 586                         if (!strcmp(arg, "--unpacked")) {
 587                                 revs->unpacked = 1;
 588                                 revs->limited = 1;
 589                                 continue;
 590                         }
 591                         *unrecognized++ = arg;
 592                         left++;
 593                         continue;
 594                 }
 595                 dotdot = strstr(arg, "..");
 596                 if (dotdot) {
 597                         unsigned char from_sha1[20];
 598                         char *next = dotdot + 2;
 599                         *dotdot = 0;
 600                         if (!*next)
 601                                 next = "HEAD";
 602                         if (!get_sha1(arg, from_sha1) && !get_sha1(next, sha1)) {
 603                                 struct commit *exclude;
 604                                 struct commit *include;
 605
 606                                 exclude = get_commit_reference(revs, arg, from_sha1, flags ^ UNINTERESTING);
 607                                 include = get_commit_reference(revs, next, sha1, flags);
 608                                 if (!exclude || !include)
 609                                         die("Invalid revision range %s..%s", arg, next);
 610                                 add_one_commit(exclude, revs);
 611                                 add_one_commit(include, revs);
 612                                 continue;
 613                         }
 614                         *dotdot = '.';
 615                 }
 616                 local_flags = 0;
 617                 if (*arg == '^') {
 618                         local_flags = UNINTERESTING;
 619                         arg++;
 620                 }
 621                 if (get_sha1(arg, sha1) < 0) {
 622                         struct stat st;
 623                         int j;
 624
 625                         if (seen_dashdash || local_flags)
 626                                 die("bad revision '%s'", arg);
 627
 628                         /* If we didn't have a "--", all filenames must exist */
 629                         for (j = i; j < argc; j++) {
 630                                 if (lstat(argv[j], &st) < 0)
 631                                         die("'%s': %s", arg, strerror(errno));
 632                         }
 633                         revs->paths = get_pathspec(revs->prefix, argv + i);
 634                         break;
 635                 }
 636                 commit = get_commit_reference(revs, arg, sha1, flags ^ local_flags);
 637                 add_one_commit(commit, revs);
 638         }
 639         if (def && !revs->commits) {
 640                 unsigned char sha1[20];
 641                 struct commit *commit;
 642                 if (get_sha1(def, sha1) < 0)
 643                         die("bad default revision '%s'", def);
 644                 commit = get_commit_reference(revs, def, sha1, 0);
 645                 add_one_commit(commit, revs);
 646         }
 647         if (revs->paths)
 648                 revs->limited = 1;
 649         return left;
 650 }
 651
 652 void prepare_revision_walk(struct rev_info *revs)
 653 {
 654         sort_by_date(&revs->commits);
 655         if (revs->limited)
 656                 limit_list(revs);
 657         if (revs->topo_order)
 658                 sort_in_topological_order(&revs->commits, revs->lifo);
 659 }
 660
 661 static int rewrite_one(struct commit **pp)
 662 {
 663         for (;;) {
 664                 struct commit *p = *pp;
 665                 if (p->object.flags & (TREECHANGE | UNINTERESTING))
 666                         return 0;
 667                 if (!p->parents)
 668                         return -1;
 669                 *pp = p->parents->item;
 670         }
 671 }
 672
 673 static void rewrite_parents(struct commit *commit)
 674 {
 675         struct commit_list **pp = &commit->parents;
 676         while (*pp) {
 677                 struct commit_list *parent = *pp;
 678                 if (rewrite_one(&parent->item) < 0) {
 679                         *pp = parent->next;
 680                         continue;
 681                 }
 682                 pp = &parent->next;
 683         }
 684 }
 685
 686 struct commit *get_revision(struct rev_info *revs)
 687 {
 688         struct commit_list *list = revs->commits;
 689
 690         if (!list)
 691                 return NULL;
 692
 693         /* Check the max_count ... */
 694         switch (revs->max_count) {
 695         case -1:
 696                 break;
 697         case 0:
 698                 return NULL;
 699         default:
 700                 revs->max_count--;
 701         }
 702
 703         do {
 704                 struct commit *commit = revs->commits->item;
 705
 706                 if (commit->object.flags & (UNINTERESTING|SHOWN))
 707                         goto next;
 708                 if (revs->min_age != -1 && (commit->date > revs->min_age))
 709                         goto next;
 710                 if (revs->max_age != -1 && (commit->date < revs->max_age))
 711                         return NULL;
 712                 if (revs->no_merges && commit->parents && commit->parents->next)
 713                         goto next;
 714                 if (revs->paths && revs->dense) {
 715                         if (!(commit->object.flags & TREECHANGE))
 716                                 goto next;
 717                         rewrite_parents(commit);
 718                 }
 719                 /* More to go? */
 720                 if (revs->max_count)
 721                         pop_most_recent_commit(&revs->commits, SEEN);
 722                 commit->object.flags |= SHOWN;
 723                 return commit;
 724 next:
 725                 pop_most_recent_commit(&revs->commits, SEEN);
 726         } while (revs->commits);
 727         return NULL;
 728 }