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