git.oblomov.eu Git - git/blob - builtin-rev-list.c

   1 #include "cache.h"
   2 #include "refs.h"
   3 #include "tag.h"
   4 #include "commit.h"
   5 #include "tree.h"
   6 #include "blob.h"
   7 #include "tree-walk.h"
   8 #include "diff.h"
   9 #include "revision.h"
  10 #include "list-objects.h"
  11 #include "builtin.h"
  12 #include "log-tree.h"
  13 #include "graph.h"
  14
  15 /* bits #0-15 in revision.h */
  16
  17 #define COUNTED         (1u<<16)
  18
  19 static const char rev_list_usage[] =
  20 "git rev-list [OPTION] <commit-id>... [ -- paths... ]\n"
  21 "  limiting output:\n"
  22 "    --max-count=nr\n"
  23 "    --max-age=epoch\n"
  24 "    --min-age=epoch\n"
  25 "    --sparse\n"
  26 "    --no-merges\n"
  27 "    --remove-empty\n"
  28 "    --all\n"
  29 "    --branches\n"
  30 "    --tags\n"
  31 "    --remotes\n"
  32 "    --stdin\n"
  33 "    --quiet\n"
  34 "  ordering output:\n"
  35 "    --topo-order\n"
  36 "    --date-order\n"
  37 "    --reverse\n"
  38 "  formatting output:\n"
  39 "    --parents\n"
  40 "    --children\n"
  41 "    --objects | --objects-edge\n"
  42 "    --unpacked\n"
  43 "    --header | --pretty\n"
  44 "    --abbrev=nr | --no-abbrev\n"
  45 "    --abbrev-commit\n"
  46 "    --left-right\n"
  47 "  special purpose:\n"
  48 "    --bisect\n"
  49 "    --bisect-vars\n"
  50 "    --bisect-all"
  51 ;
  52
  53 static struct rev_info revs;
  54
  55 static int bisect_list;
  56 static int show_timestamp;
  57 static int hdr_termination;
  58 static const char *header_prefix;
  59
  60 static void finish_commit(struct commit *commit);
  61 static void show_commit(struct commit *commit)
  62 {
  63         graph_show_commit(revs.graph);
  64
  65         if (show_timestamp)
  66                 printf("%lu ", commit->date);
  67         if (header_prefix)
  68                 fputs(header_prefix, stdout);
  69
  70         if (!revs.graph) {
  71                 if (commit->object.flags & BOUNDARY)
  72                         putchar('-');
  73                 else if (commit->object.flags & UNINTERESTING)
  74                         putchar('^');
  75                 else if (revs.left_right) {
  76                         if (commit->object.flags & SYMMETRIC_LEFT)
  77                                 putchar('<');
  78                         else
  79                                 putchar('>');
  80                 }
  81         }
  82         if (revs.abbrev_commit && revs.abbrev)
  83                 fputs(find_unique_abbrev(commit->object.sha1, revs.abbrev),
  84                       stdout);
  85         else
  86                 fputs(sha1_to_hex(commit->object.sha1), stdout);
  87         if (revs.print_parents) {
  88                 struct commit_list *parents = commit->parents;
  89                 while (parents) {
  90                         printf(" %s", sha1_to_hex(parents->item->object.sha1));
  91                         parents = parents->next;
  92                 }
  93         }
  94         if (revs.children.name) {
  95                 struct commit_list *children;
  96
  97                 children = lookup_decoration(&revs.children, &commit->object);
  98                 while (children) {
  99                         printf(" %s", sha1_to_hex(children->item->object.sha1));
 100                         children = children->next;
 101                 }
 102         }
 103         show_decorations(&revs, commit);
 104         if (revs.commit_format == CMIT_FMT_ONELINE)
 105                 putchar(' ');
 106         else
 107                 putchar('\n');
 108
 109         if (revs.verbose_header && commit->buffer) {
 110                 struct strbuf buf = STRBUF_INIT;
 111                 pretty_print_commit(revs.commit_format, commit,
 112                                     &buf, revs.abbrev, NULL, NULL,
 113                                     revs.date_mode, 0);
 114                 if (revs.graph) {
 115                         if (buf.len) {
 116                                 if (revs.commit_format != CMIT_FMT_ONELINE)
 117                                         graph_show_oneline(revs.graph);
 118
 119                                 graph_show_commit_msg(revs.graph, &buf);
 120
 121                                 /*
 122                                  * Add a newline after the commit message.
 123                                  *
 124                                  * Usually, this newline produces a blank
 125                                  * padding line between entries, in which case
 126                                  * we need to add graph padding on this line.
 127                                  *
 128                                  * However, the commit message may not end in a
 129                                  * newline.  In this case the newline simply
 130                                  * ends the last line of the commit message,
 131                                  * and we don't need any graph output.  (This
 132                                  * always happens with CMIT_FMT_ONELINE, and it
 133                                  * happens with CMIT_FMT_USERFORMAT when the
 134                                  * format doesn't explicitly end in a newline.)
 135                                  */
 136                                 if (buf.len && buf.buf[buf.len - 1] == '\n')
 137                                         graph_show_padding(revs.graph);
 138                                 putchar('\n');
 139                         } else {
 140                                 /*
 141                                  * If the message buffer is empty, just show
 142                                  * the rest of the graph output for this
 143                                  * commit.
 144                                  */
 145                                 if (graph_show_remainder(revs.graph))
 146                                         putchar('\n');
 147                         }
 148                 } else {
 149                         if (buf.len)
 150                                 printf("%s%c", buf.buf, hdr_termination);
 151                 }
 152                 strbuf_release(&buf);
 153         } else {
 154                 if (graph_show_remainder(revs.graph))
 155                         putchar('\n');
 156         }
 157         maybe_flush_or_die(stdout, "stdout");
 158         finish_commit(commit);
 159 }
 160
 161 static void finish_commit(struct commit *commit)
 162 {
 163         if (commit->parents) {
 164                 free_commit_list(commit->parents);
 165                 commit->parents = NULL;
 166         }
 167         free(commit->buffer);
 168         commit->buffer = NULL;
 169 }
 170
 171 static void finish_object(struct object *obj, const struct name_path *path, const char *name)
 172 {
 173         if (obj->type == OBJ_BLOB && !has_sha1_file(obj->sha1))
 174                 die("missing blob object '%s'", sha1_to_hex(obj->sha1));
 175 }
 176
 177 static void show_object(struct object *obj, const struct name_path *path, const char *component)
 178 {
 179         char *name = path_name(path, component);
 180         /* An object with name "foo\n0000000..." can be used to
 181          * confuse downstream "git pack-objects" very badly.
 182          */
 183         const char *ep = strchr(name, '\n');
 184
 185         finish_object(obj, path, name);
 186         if (ep) {
 187                 printf("%s %.*s\n", sha1_to_hex(obj->sha1),
 188                        (int) (ep - name),
 189                        name);
 190         }
 191         else
 192                 printf("%s %s\n", sha1_to_hex(obj->sha1), name);
 193         free(name);
 194 }
 195
 196 static void show_edge(struct commit *commit)
 197 {
 198         printf("-%s\n", sha1_to_hex(commit->object.sha1));
 199 }
 200
 201 /*
 202  * This is a truly stupid algorithm, but it's only
 203  * used for bisection, and we just don't care enough.
 204  *
 205  * We care just barely enough to avoid recursing for
 206  * non-merge entries.
 207  */
 208 static int count_distance(struct commit_list *entry)
 209 {
 210         int nr = 0;
 211
 212         while (entry) {
 213                 struct commit *commit = entry->item;
 214                 struct commit_list *p;
 215
 216                 if (commit->object.flags & (UNINTERESTING | COUNTED))
 217                         break;
 218                 if (!(commit->object.flags & TREESAME))
 219                         nr++;
 220                 commit->object.flags |= COUNTED;
 221                 p = commit->parents;
 222                 entry = p;
 223                 if (p) {
 224                         p = p->next;
 225                         while (p) {
 226                                 nr += count_distance(p);
 227                                 p = p->next;
 228                         }
 229                 }
 230         }
 231
 232         return nr;
 233 }
 234
 235 static void clear_distance(struct commit_list *list)
 236 {
 237         while (list) {
 238                 struct commit *commit = list->item;
 239                 commit->object.flags &= ~COUNTED;
 240                 list = list->next;
 241         }
 242 }
 243
 244 #define DEBUG_BISECT 0
 245
 246 static inline int weight(struct commit_list *elem)
 247 {
 248         return *((int*)(elem->item->util));
 249 }
 250
 251 static inline void weight_set(struct commit_list *elem, int weight)
 252 {
 253         *((int*)(elem->item->util)) = weight;
 254 }
 255
 256 static int count_interesting_parents(struct commit *commit)
 257 {
 258         struct commit_list *p;
 259         int count;
 260
 261         for (count = 0, p = commit->parents; p; p = p->next) {
 262                 if (p->item->object.flags & UNINTERESTING)
 263                         continue;
 264                 count++;
 265         }
 266         return count;
 267 }
 268
 269 static inline int halfway(struct commit_list *p, int nr)
 270 {
 271         /*
 272          * Don't short-cut something we are not going to return!
 273          */
 274         if (p->item->object.flags & TREESAME)
 275                 return 0;
 276         if (DEBUG_BISECT)
 277                 return 0;
 278         /*
 279          * 2 and 3 are halfway of 5.
 280          * 3 is halfway of 6 but 2 and 4 are not.
 281          */
 282         switch (2 * weight(p) - nr) {
 283         case -1: case 0: case 1:
 284                 return 1;
 285         default:
 286                 return 0;
 287         }
 288 }
 289
 290 #if !DEBUG_BISECT
 291 #define show_list(a,b,c,d) do { ; } while (0)
 292 #else
 293 static void show_list(const char *debug, int counted, int nr,
 294                       struct commit_list *list)
 295 {
 296         struct commit_list *p;
 297
 298         fprintf(stderr, "%s (%d/%d)\n", debug, counted, nr);
 299
 300         for (p = list; p; p = p->next) {
 301                 struct commit_list *pp;
 302                 struct commit *commit = p->item;
 303                 unsigned flags = commit->object.flags;
 304                 enum object_type type;
 305                 unsigned long size;
 306                 char *buf = read_sha1_file(commit->object.sha1, &type, &size);
 307                 char *ep, *sp;
 308
 309                 fprintf(stderr, "%c%c%c ",
 310                         (flags & TREESAME) ? ' ' : 'T',
 311                         (flags & UNINTERESTING) ? 'U' : ' ',
 312                         (flags & COUNTED) ? 'C' : ' ');
 313                 if (commit->util)
 314                         fprintf(stderr, "%3d", weight(p));
 315                 else
 316                         fprintf(stderr, "---");
 317                 fprintf(stderr, " %.*s", 8, sha1_to_hex(commit->object.sha1));
 318                 for (pp = commit->parents; pp; pp = pp->next)
 319                         fprintf(stderr, " %.*s", 8,
 320                                 sha1_to_hex(pp->item->object.sha1));
 321
 322                 sp = strstr(buf, "\n\n");
 323                 if (sp) {
 324                         sp += 2;
 325                         for (ep = sp; *ep && *ep != '\n'; ep++)
 326                                 ;
 327                         fprintf(stderr, " %.*s", (int)(ep - sp), sp);
 328                 }
 329                 fprintf(stderr, "\n");
 330         }
 331 }
 332 #endif /* DEBUG_BISECT */
 333
 334 static struct commit_list *best_bisection(struct commit_list *list, int nr)
 335 {
 336         struct commit_list *p, *best;
 337         int best_distance = -1;
 338
 339         best = list;
 340         for (p = list; p; p = p->next) {
 341                 int distance;
 342                 unsigned flags = p->item->object.flags;
 343
 344                 if (flags & TREESAME)
 345                         continue;
 346                 distance = weight(p);
 347                 if (nr - distance < distance)
 348                         distance = nr - distance;
 349                 if (distance > best_distance) {
 350                         best = p;
 351                         best_distance = distance;
 352                 }
 353         }
 354
 355         return best;
 356 }
 357
 358 struct commit_dist {
 359         struct commit *commit;
 360         int distance;
 361 };
 362
 363 static int compare_commit_dist(const void *a_, const void *b_)
 364 {
 365         struct commit_dist *a, *b;
 366
 367         a = (struct commit_dist *)a_;
 368         b = (struct commit_dist *)b_;
 369         if (a->distance != b->distance)
 370                 return b->distance - a->distance; /* desc sort */
 371         return hashcmp(a->commit->object.sha1, b->commit->object.sha1);
 372 }
 373
 374 static struct commit_list *best_bisection_sorted(struct commit_list *list, int nr)
 375 {
 376         struct commit_list *p;
 377         struct commit_dist *array = xcalloc(nr, sizeof(*array));
 378         int cnt, i;
 379
 380         for (p = list, cnt = 0; p; p = p->next) {
 381                 int distance;
 382                 unsigned flags = p->item->object.flags;
 383
 384                 if (flags & TREESAME)
 385                         continue;
 386                 distance = weight(p);
 387                 if (nr - distance < distance)
 388                         distance = nr - distance;
 389                 array[cnt].commit = p->item;
 390                 array[cnt].distance = distance;
 391                 cnt++;
 392         }
 393         qsort(array, cnt, sizeof(*array), compare_commit_dist);
 394         for (p = list, i = 0; i < cnt; i++) {
 395                 struct name_decoration *r = xmalloc(sizeof(*r) + 100);
 396                 struct object *obj = &(array[i].commit->object);
 397
 398                 sprintf(r->name, "dist=%d", array[i].distance);
 399                 r->next = add_decoration(&name_decoration, obj, r);
 400                 p->item = array[i].commit;
 401                 p = p->next;
 402         }
 403         if (p)
 404                 p->next = NULL;
 405         free(array);
 406         return list;
 407 }
 408
 409 /*
 410  * zero or positive weight is the number of interesting commits it can
 411  * reach, including itself.  Especially, weight = 0 means it does not
 412  * reach any tree-changing commits (e.g. just above uninteresting one
 413  * but traversal is with pathspec).
 414  *
 415  * weight = -1 means it has one parent and its distance is yet to
 416  * be computed.
 417  *
 418  * weight = -2 means it has more than one parent and its distance is
 419  * unknown.  After running count_distance() first, they will get zero
 420  * or positive distance.
 421  */
 422 static struct commit_list *do_find_bisection(struct commit_list *list,
 423                                              int nr, int *weights,
 424                                              int find_all)
 425 {
 426         int n, counted;
 427         struct commit_list *p;
 428
 429         counted = 0;
 430
 431         for (n = 0, p = list; p; p = p->next) {
 432                 struct commit *commit = p->item;
 433                 unsigned flags = commit->object.flags;
 434
 435                 p->item->util = &weights[n++];
 436                 switch (count_interesting_parents(commit)) {
 437                 case 0:
 438                         if (!(flags & TREESAME)) {
 439                                 weight_set(p, 1);
 440                                 counted++;
 441                                 show_list("bisection 2 count one",
 442                                           counted, nr, list);
 443                         }
 444                         /*
 445                          * otherwise, it is known not to reach any
 446                          * tree-changing commit and gets weight 0.
 447                          */
 448                         break;
 449                 case 1:
 450                         weight_set(p, -1);
 451                         break;
 452                 default:
 453                         weight_set(p, -2);
 454                         break;
 455                 }
 456         }
 457
 458         show_list("bisection 2 initialize", counted, nr, list);
 459
 460         /*
 461          * If you have only one parent in the resulting set
 462          * then you can reach one commit more than that parent
 463          * can reach.  So we do not have to run the expensive
 464          * count_distance() for single strand of pearls.
 465          *
 466          * However, if you have more than one parents, you cannot
 467          * just add their distance and one for yourself, since
 468          * they usually reach the same ancestor and you would
 469          * end up counting them twice that way.
 470          *
 471          * So we will first count distance of merges the usual
 472          * way, and then fill the blanks using cheaper algorithm.
 473          */
 474         for (p = list; p; p = p->next) {
 475                 if (p->item->object.flags & UNINTERESTING)
 476                         continue;
 477                 if (weight(p) != -2)
 478                         continue;
 479                 weight_set(p, count_distance(p));
 480                 clear_distance(list);
 481
 482                 /* Does it happen to be at exactly half-way? */
 483                 if (!find_all && halfway(p, nr))
 484                         return p;
 485                 counted++;
 486         }
 487
 488         show_list("bisection 2 count_distance", counted, nr, list);
 489
 490         while (counted < nr) {
 491                 for (p = list; p; p = p->next) {
 492                         struct commit_list *q;
 493                         unsigned flags = p->item->object.flags;
 494
 495                         if (0 <= weight(p))
 496                                 continue;
 497                         for (q = p->item->parents; q; q = q->next) {
 498                                 if (q->item->object.flags & UNINTERESTING)
 499                                         continue;
 500                                 if (0 <= weight(q))
 501                                         break;
 502                         }
 503                         if (!q)
 504                                 continue;
 505
 506                         /*
 507                          * weight for p is unknown but q is known.
 508                          * add one for p itself if p is to be counted,
 509                          * otherwise inherit it from q directly.
 510                          */
 511                         if (!(flags & TREESAME)) {
 512                                 weight_set(p, weight(q)+1);
 513                                 counted++;
 514                                 show_list("bisection 2 count one",
 515                                           counted, nr, list);
 516                         }
 517                         else
 518                                 weight_set(p, weight(q));
 519
 520                         /* Does it happen to be at exactly half-way? */
 521                         if (!find_all && halfway(p, nr))
 522                                 return p;
 523                 }
 524         }
 525
 526         show_list("bisection 2 counted all", counted, nr, list);
 527
 528         if (!find_all)
 529                 return best_bisection(list, nr);
 530         else
 531                 return best_bisection_sorted(list, nr);
 532 }
 533
 534 static struct commit_list *find_bisection(struct commit_list *list,
 535                                           int *reaches, int *all,
 536                                           int find_all)
 537 {
 538         int nr, on_list;
 539         struct commit_list *p, *best, *next, *last;
 540         int *weights;
 541
 542         show_list("bisection 2 entry", 0, 0, list);
 543
 544         /*
 545          * Count the number of total and tree-changing items on the
 546          * list, while reversing the list.
 547          */
 548         for (nr = on_list = 0, last = NULL, p = list;
 549              p;
 550              p = next) {
 551                 unsigned flags = p->item->object.flags;
 552
 553                 next = p->next;
 554                 if (flags & UNINTERESTING)
 555                         continue;
 556                 p->next = last;
 557                 last = p;
 558                 if (!(flags & TREESAME))
 559                         nr++;
 560                 on_list++;
 561         }
 562         list = last;
 563         show_list("bisection 2 sorted", 0, nr, list);
 564
 565         *all = nr;
 566         weights = xcalloc(on_list, sizeof(*weights));
 567
 568         /* Do the real work of finding bisection commit. */
 569         best = do_find_bisection(list, nr, weights, find_all);
 570         if (best) {
 571                 if (!find_all)
 572                         best->next = NULL;
 573                 *reaches = weight(best);
 574         }
 575         free(weights);
 576         return best;
 577 }
 578
 579 int cmd_rev_list(int argc, const char **argv, const char *prefix)
 580 {
 581         struct commit_list *list;
 582         int i;
 583         int read_from_stdin = 0;
 584         int bisect_show_vars = 0;
 585         int bisect_find_all = 0;
 586         int quiet = 0;
 587
 588         git_config(git_default_config, NULL);
 589         init_revisions(&revs, prefix);
 590         revs.abbrev = 0;
 591         revs.commit_format = CMIT_FMT_UNSPECIFIED;
 592         argc = setup_revisions(argc, argv, &revs, NULL);
 593
 594         quiet = DIFF_OPT_TST(&revs.diffopt, QUIET);
 595         for (i = 1 ; i < argc; i++) {
 596                 const char *arg = argv[i];
 597
 598                 if (!strcmp(arg, "--header")) {
 599                         revs.verbose_header = 1;
 600                         continue;
 601                 }
 602                 if (!strcmp(arg, "--timestamp")) {
 603                         show_timestamp = 1;
 604                         continue;
 605                 }
 606                 if (!strcmp(arg, "--bisect")) {
 607                         bisect_list = 1;
 608                         continue;
 609                 }
 610                 if (!strcmp(arg, "--bisect-all")) {
 611                         bisect_list = 1;
 612                         bisect_find_all = 1;
 613                         revs.show_decorations = 1;
 614                         continue;
 615                 }
 616                 if (!strcmp(arg, "--bisect-vars")) {
 617                         bisect_list = 1;
 618                         bisect_show_vars = 1;
 619                         continue;
 620                 }
 621                 if (!strcmp(arg, "--stdin")) {
 622                         if (read_from_stdin++)
 623                                 die("--stdin given twice?");
 624                         read_revisions_from_stdin(&revs);
 625                         continue;
 626                 }
 627                 usage(rev_list_usage);
 628
 629         }
 630         if (revs.commit_format != CMIT_FMT_UNSPECIFIED) {
 631                 /* The command line has a --pretty  */
 632                 hdr_termination = '\n';
 633                 if (revs.commit_format == CMIT_FMT_ONELINE)
 634                         header_prefix = "";
 635                 else
 636                         header_prefix = "commit ";
 637         }
 638         else if (revs.verbose_header)
 639                 /* Only --header was specified */
 640                 revs.commit_format = CMIT_FMT_RAW;
 641
 642         list = revs.commits;
 643
 644         if ((!list &&
 645              (!(revs.tag_objects||revs.tree_objects||revs.blob_objects) &&
 646               !revs.pending.nr)) ||
 647             revs.diff)
 648                 usage(rev_list_usage);
 649
 650         save_commit_buffer = revs.verbose_header ||
 651                 revs.grep_filter.pattern_list;
 652         if (bisect_list)
 653                 revs.limited = 1;
 654
 655         if (prepare_revision_walk(&revs))
 656                 die("revision walk setup failed");
 657         if (revs.tree_objects)
 658                 mark_edges_uninteresting(revs.commits, &revs, show_edge);
 659
 660         if (bisect_list) {
 661                 int reaches = reaches, all = all;
 662
 663                 revs.commits = find_bisection(revs.commits, &reaches, &all,
 664                                               bisect_find_all);
 665                 if (bisect_show_vars) {
 666                         int cnt;
 667                         char hex[41];
 668                         if (!revs.commits)
 669                                 return 1;
 670                         /*
 671                          * revs.commits can reach "reaches" commits among
 672                          * "all" commits.  If it is good, then there are
 673                          * (all-reaches) commits left to be bisected.
 674                          * On the other hand, if it is bad, then the set
 675                          * to bisect is "reaches".
 676                          * A bisect set of size N has (N-1) commits further
 677                          * to test, as we already know one bad one.
 678                          */
 679                         cnt = all - reaches;
 680                         if (cnt < reaches)
 681                                 cnt = reaches;
 682                         strcpy(hex, sha1_to_hex(revs.commits->item->object.sha1));
 683
 684                         if (bisect_find_all) {
 685                                 traverse_commit_list(&revs, show_commit, show_object);
 686                                 printf("------\n");
 687                         }
 688
 689                         printf("bisect_rev=%s\n"
 690                                "bisect_nr=%d\n"
 691                                "bisect_good=%d\n"
 692                                "bisect_bad=%d\n"
 693                                "bisect_all=%d\n",
 694                                hex,
 695                                cnt - 1,
 696                                all - reaches - 1,
 697                                reaches - 1,
 698                                all);
 699                         return 0;
 700                 }
 701         }
 702
 703         traverse_commit_list(&revs,
 704                 quiet ? finish_commit : show_commit,
 705                 quiet ? finish_object : show_object);
 706
 707         return 0;
 708 }