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 "    --objects | --objects-edge\n"
  41 "    --unpacked\n"
  42 "    --header | --pretty\n"
  43 "    --abbrev=nr | --no-abbrev\n"
  44 "    --abbrev-commit\n"
  45 "    --left-right\n"
  46 "  special purpose:\n"
  47 "    --bisect\n"
  48 "    --bisect-vars\n"
  49 "    --bisect-all"
  50 ;
  51
  52 static struct rev_info revs;
  53
  54 static int bisect_list;
  55 static int show_timestamp;
  56 static int hdr_termination;
  57 static const char *header_prefix;
  58
  59 static void finish_commit(struct commit *commit);
  60 static void show_commit(struct commit *commit)
  61 {
  62         graph_show_commit(revs.graph);
  63
  64         if (show_timestamp)
  65                 printf("%lu ", commit->date);
  66         if (header_prefix)
  67                 fputs(header_prefix, stdout);
  68
  69         if (!revs.graph) {
  70                 if (commit->object.flags & BOUNDARY)
  71                         putchar('-');
  72                 else if (commit->object.flags & UNINTERESTING)
  73                         putchar('^');
  74                 else if (revs.left_right) {
  75                         if (commit->object.flags & SYMMETRIC_LEFT)
  76                                 putchar('<');
  77                         else
  78                                 putchar('>');
  79                 }
  80         }
  81         if (revs.abbrev_commit && revs.abbrev)
  82                 fputs(find_unique_abbrev(commit->object.sha1, revs.abbrev),
  83                       stdout);
  84         else
  85                 fputs(sha1_to_hex(commit->object.sha1), stdout);
  86         if (revs.print_parents) {
  87                 struct commit_list *parents = commit->parents;
  88                 while (parents) {
  89                         printf(" %s", sha1_to_hex(parents->item->object.sha1));
  90                         parents = parents->next;
  91                 }
  92         }
  93         show_decorations(commit);
  94         if (revs.commit_format == CMIT_FMT_ONELINE)
  95                 putchar(' ');
  96         else
  97                 putchar('\n');
  98
  99         if (revs.verbose_header && commit->buffer) {
 100                 struct strbuf buf;
 101                 strbuf_init(&buf, 0);
 102                 pretty_print_commit(revs.commit_format, commit,
 103                                     &buf, revs.abbrev, NULL, NULL,
 104                                     revs.date_mode, 0);
 105                 if (revs.graph) {
 106                         if (buf.len) {
 107                                 if (revs.commit_format != CMIT_FMT_ONELINE)
 108                                         graph_show_oneline(revs.graph);
 109
 110                                 graph_show_commit_msg(revs.graph, &buf);
 111
 112                                 /*
 113                                  * Add a newline after the commit message.
 114                                  *
 115                                  * Usually, this newline produces a blank
 116                                  * padding line between entries, in which case
 117                                  * we need to add graph padding on this line.
 118                                  *
 119                                  * However, the commit message may not end in a
 120                                  * newline.  In this case the newline simply
 121                                  * ends the last line of the commit message,
 122                                  * and we don't need any graph output.  (This
 123                                  * always happens with CMIT_FMT_ONELINE, and it
 124                                  * happens with CMIT_FMT_USERFORMAT when the
 125                                  * format doesn't explicitly end in a newline.)
 126                                  */
 127                                 if (buf.len && buf.buf[buf.len - 1] == '\n')
 128                                         graph_show_padding(revs.graph);
 129                                 putchar('\n');
 130                         } else {
 131                                 /*
 132                                  * If the message buffer is empty, just show
 133                                  * the rest of the graph output for this
 134                                  * commit.
 135                                  */
 136                                 if (graph_show_remainder(revs.graph))
 137                                         putchar('\n');
 138                         }
 139                 } else {
 140                         if (buf.len)
 141                                 printf("%s%c", buf.buf, hdr_termination);
 142                 }
 143                 strbuf_release(&buf);
 144         } else {
 145                 if (graph_show_remainder(revs.graph))
 146                         putchar('\n');
 147         }
 148         maybe_flush_or_die(stdout, "stdout");
 149         finish_commit(commit);
 150 }
 151
 152 static void finish_commit(struct commit *commit)
 153 {
 154         if (commit->parents) {
 155                 free_commit_list(commit->parents);
 156                 commit->parents = NULL;
 157         }
 158         free(commit->buffer);
 159         commit->buffer = NULL;
 160 }
 161
 162 static void finish_object(struct object_array_entry *p)
 163 {
 164         if (p->item->type == OBJ_BLOB && !has_sha1_file(p->item->sha1))
 165                 die("missing blob object '%s'", sha1_to_hex(p->item->sha1));
 166 }
 167
 168 static void show_object(struct object_array_entry *p)
 169 {
 170         /* An object with name "foo\n0000000..." can be used to
 171          * confuse downstream git-pack-objects very badly.
 172          */
 173         const char *ep = strchr(p->name, '\n');
 174
 175         finish_object(p);
 176         if (ep) {
 177                 printf("%s %.*s\n", sha1_to_hex(p->item->sha1),
 178                        (int) (ep - p->name),
 179                        p->name);
 180         }
 181         else
 182                 printf("%s %s\n", sha1_to_hex(p->item->sha1), p->name);
 183 }
 184
 185 static void show_edge(struct commit *commit)
 186 {
 187         printf("-%s\n", sha1_to_hex(commit->object.sha1));
 188 }
 189
 190 /*
 191  * This is a truly stupid algorithm, but it's only
 192  * used for bisection, and we just don't care enough.
 193  *
 194  * We care just barely enough to avoid recursing for
 195  * non-merge entries.
 196  */
 197 static int count_distance(struct commit_list *entry)
 198 {
 199         int nr = 0;
 200
 201         while (entry) {
 202                 struct commit *commit = entry->item;
 203                 struct commit_list *p;
 204
 205                 if (commit->object.flags & (UNINTERESTING | COUNTED))
 206                         break;
 207                 if (!(commit->object.flags & TREESAME))
 208                         nr++;
 209                 commit->object.flags |= COUNTED;
 210                 p = commit->parents;
 211                 entry = p;
 212                 if (p) {
 213                         p = p->next;
 214                         while (p) {
 215                                 nr += count_distance(p);
 216                                 p = p->next;
 217                         }
 218                 }
 219         }
 220
 221         return nr;
 222 }
 223
 224 static void clear_distance(struct commit_list *list)
 225 {
 226         while (list) {
 227                 struct commit *commit = list->item;
 228                 commit->object.flags &= ~COUNTED;
 229                 list = list->next;
 230         }
 231 }
 232
 233 #define DEBUG_BISECT 0
 234
 235 static inline int weight(struct commit_list *elem)
 236 {
 237         return *((int*)(elem->item->util));
 238 }
 239
 240 static inline void weight_set(struct commit_list *elem, int weight)
 241 {
 242         *((int*)(elem->item->util)) = weight;
 243 }
 244
 245 static int count_interesting_parents(struct commit *commit)
 246 {
 247         struct commit_list *p;
 248         int count;
 249
 250         for (count = 0, p = commit->parents; p; p = p->next) {
 251                 if (p->item->object.flags & UNINTERESTING)
 252                         continue;
 253                 count++;
 254         }
 255         return count;
 256 }
 257
 258 static inline int halfway(struct commit_list *p, int nr)
 259 {
 260         /*
 261          * Don't short-cut something we are not going to return!
 262          */
 263         if (p->item->object.flags & TREESAME)
 264                 return 0;
 265         if (DEBUG_BISECT)
 266                 return 0;
 267         /*
 268          * 2 and 3 are halfway of 5.
 269          * 3 is halfway of 6 but 2 and 4 are not.
 270          */
 271         switch (2 * weight(p) - nr) {
 272         case -1: case 0: case 1:
 273                 return 1;
 274         default:
 275                 return 0;
 276         }
 277 }
 278
 279 #if !DEBUG_BISECT
 280 #define show_list(a,b,c,d) do { ; } while (0)
 281 #else
 282 static void show_list(const char *debug, int counted, int nr,
 283                       struct commit_list *list)
 284 {
 285         struct commit_list *p;
 286
 287         fprintf(stderr, "%s (%d/%d)\n", debug, counted, nr);
 288
 289         for (p = list; p; p = p->next) {
 290                 struct commit_list *pp;
 291                 struct commit *commit = p->item;
 292                 unsigned flags = commit->object.flags;
 293                 enum object_type type;
 294                 unsigned long size;
 295                 char *buf = read_sha1_file(commit->object.sha1, &type, &size);
 296                 char *ep, *sp;
 297
 298                 fprintf(stderr, "%c%c%c ",
 299                         (flags & TREESAME) ? ' ' : 'T',
 300                         (flags & UNINTERESTING) ? 'U' : ' ',
 301                         (flags & COUNTED) ? 'C' : ' ');
 302                 if (commit->util)
 303                         fprintf(stderr, "%3d", weight(p));
 304                 else
 305                         fprintf(stderr, "---");
 306                 fprintf(stderr, " %.*s", 8, sha1_to_hex(commit->object.sha1));
 307                 for (pp = commit->parents; pp; pp = pp->next)
 308                         fprintf(stderr, " %.*s", 8,
 309                                 sha1_to_hex(pp->item->object.sha1));
 310
 311                 sp = strstr(buf, "\n\n");
 312                 if (sp) {
 313                         sp += 2;
 314                         for (ep = sp; *ep && *ep != '\n'; ep++)
 315                                 ;
 316                         fprintf(stderr, " %.*s", (int)(ep - sp), sp);
 317                 }
 318                 fprintf(stderr, "\n");
 319         }
 320 }
 321 #endif /* DEBUG_BISECT */
 322
 323 static struct commit_list *best_bisection(struct commit_list *list, int nr)
 324 {
 325         struct commit_list *p, *best;
 326         int best_distance = -1;
 327
 328         best = list;
 329         for (p = list; p; p = p->next) {
 330                 int distance;
 331                 unsigned flags = p->item->object.flags;
 332
 333                 if (flags & TREESAME)
 334                         continue;
 335                 distance = weight(p);
 336                 if (nr - distance < distance)
 337                         distance = nr - distance;
 338                 if (distance > best_distance) {
 339                         best = p;
 340                         best_distance = distance;
 341                 }
 342         }
 343
 344         return best;
 345 }
 346
 347 struct commit_dist {
 348         struct commit *commit;
 349         int distance;
 350 };
 351
 352 static int compare_commit_dist(const void *a_, const void *b_)
 353 {
 354         struct commit_dist *a, *b;
 355
 356         a = (struct commit_dist *)a_;
 357         b = (struct commit_dist *)b_;
 358         if (a->distance != b->distance)
 359                 return b->distance - a->distance; /* desc sort */
 360         return hashcmp(a->commit->object.sha1, b->commit->object.sha1);
 361 }
 362
 363 static struct commit_list *best_bisection_sorted(struct commit_list *list, int nr)
 364 {
 365         struct commit_list *p;
 366         struct commit_dist *array = xcalloc(nr, sizeof(*array));
 367         int cnt, i;
 368
 369         for (p = list, cnt = 0; p; p = p->next) {
 370                 int distance;
 371                 unsigned flags = p->item->object.flags;
 372
 373                 if (flags & TREESAME)
 374                         continue;
 375                 distance = weight(p);
 376                 if (nr - distance < distance)
 377                         distance = nr - distance;
 378                 array[cnt].commit = p->item;
 379                 array[cnt].distance = distance;
 380                 cnt++;
 381         }
 382         qsort(array, cnt, sizeof(*array), compare_commit_dist);
 383         for (p = list, i = 0; i < cnt; i++) {
 384                 struct name_decoration *r = xmalloc(sizeof(*r) + 100);
 385                 struct object *obj = &(array[i].commit->object);
 386
 387                 sprintf(r->name, "dist=%d", array[i].distance);
 388                 r->next = add_decoration(&name_decoration, obj, r);
 389                 p->item = array[i].commit;
 390                 p = p->next;
 391         }
 392         if (p)
 393                 p->next = NULL;
 394         free(array);
 395         return list;
 396 }
 397
 398 /*
 399  * zero or positive weight is the number of interesting commits it can
 400  * reach, including itself.  Especially, weight = 0 means it does not
 401  * reach any tree-changing commits (e.g. just above uninteresting one
 402  * but traversal is with pathspec).
 403  *
 404  * weight = -1 means it has one parent and its distance is yet to
 405  * be computed.
 406  *
 407  * weight = -2 means it has more than one parent and its distance is
 408  * unknown.  After running count_distance() first, they will get zero
 409  * or positive distance.
 410  */
 411 static struct commit_list *do_find_bisection(struct commit_list *list,
 412                                              int nr, int *weights,
 413                                              int find_all)
 414 {
 415         int n, counted;
 416         struct commit_list *p;
 417
 418         counted = 0;
 419
 420         for (n = 0, p = list; p; p = p->next) {
 421                 struct commit *commit = p->item;
 422                 unsigned flags = commit->object.flags;
 423
 424                 p->item->util = &weights[n++];
 425                 switch (count_interesting_parents(commit)) {
 426                 case 0:
 427                         if (!(flags & TREESAME)) {
 428                                 weight_set(p, 1);
 429                                 counted++;
 430                                 show_list("bisection 2 count one",
 431                                           counted, nr, list);
 432                         }
 433                         /*
 434                          * otherwise, it is known not to reach any
 435                          * tree-changing commit and gets weight 0.
 436                          */
 437                         break;
 438                 case 1:
 439                         weight_set(p, -1);
 440                         break;
 441                 default:
 442                         weight_set(p, -2);
 443                         break;
 444                 }
 445         }
 446
 447         show_list("bisection 2 initialize", counted, nr, list);
 448
 449         /*
 450          * If you have only one parent in the resulting set
 451          * then you can reach one commit more than that parent
 452          * can reach.  So we do not have to run the expensive
 453          * count_distance() for single strand of pearls.
 454          *
 455          * However, if you have more than one parents, you cannot
 456          * just add their distance and one for yourself, since
 457          * they usually reach the same ancestor and you would
 458          * end up counting them twice that way.
 459          *
 460          * So we will first count distance of merges the usual
 461          * way, and then fill the blanks using cheaper algorithm.
 462          */
 463         for (p = list; p; p = p->next) {
 464                 if (p->item->object.flags & UNINTERESTING)
 465                         continue;
 466                 if (weight(p) != -2)
 467                         continue;
 468                 weight_set(p, count_distance(p));
 469                 clear_distance(list);
 470
 471                 /* Does it happen to be at exactly half-way? */
 472                 if (!find_all && halfway(p, nr))
 473                         return p;
 474                 counted++;
 475         }
 476
 477         show_list("bisection 2 count_distance", counted, nr, list);
 478
 479         while (counted < nr) {
 480                 for (p = list; p; p = p->next) {
 481                         struct commit_list *q;
 482                         unsigned flags = p->item->object.flags;
 483
 484                         if (0 <= weight(p))
 485                                 continue;
 486                         for (q = p->item->parents; q; q = q->next) {
 487                                 if (q->item->object.flags & UNINTERESTING)
 488                                         continue;
 489                                 if (0 <= weight(q))
 490                                         break;
 491                         }
 492                         if (!q)
 493                                 continue;
 494
 495                         /*
 496                          * weight for p is unknown but q is known.
 497                          * add one for p itself if p is to be counted,
 498                          * otherwise inherit it from q directly.
 499                          */
 500                         if (!(flags & TREESAME)) {
 501                                 weight_set(p, weight(q)+1);
 502                                 counted++;
 503                                 show_list("bisection 2 count one",
 504                                           counted, nr, list);
 505                         }
 506                         else
 507                                 weight_set(p, weight(q));
 508
 509                         /* Does it happen to be at exactly half-way? */
 510                         if (!find_all && halfway(p, nr))
 511                                 return p;
 512                 }
 513         }
 514
 515         show_list("bisection 2 counted all", counted, nr, list);
 516
 517         if (!find_all)
 518                 return best_bisection(list, nr);
 519         else
 520                 return best_bisection_sorted(list, nr);
 521 }
 522
 523 static struct commit_list *find_bisection(struct commit_list *list,
 524                                           int *reaches, int *all,
 525                                           int find_all)
 526 {
 527         int nr, on_list;
 528         struct commit_list *p, *best, *next, *last;
 529         int *weights;
 530
 531         show_list("bisection 2 entry", 0, 0, list);
 532
 533         /*
 534          * Count the number of total and tree-changing items on the
 535          * list, while reversing the list.
 536          */
 537         for (nr = on_list = 0, last = NULL, p = list;
 538              p;
 539              p = next) {
 540                 unsigned flags = p->item->object.flags;
 541
 542                 next = p->next;
 543                 if (flags & UNINTERESTING)
 544                         continue;
 545                 p->next = last;
 546                 last = p;
 547                 if (!(flags & TREESAME))
 548                         nr++;
 549                 on_list++;
 550         }
 551         list = last;
 552         show_list("bisection 2 sorted", 0, nr, list);
 553
 554         *all = nr;
 555         weights = xcalloc(on_list, sizeof(*weights));
 556
 557         /* Do the real work of finding bisection commit. */
 558         best = do_find_bisection(list, nr, weights, find_all);
 559         if (best) {
 560                 if (!find_all)
 561                         best->next = NULL;
 562                 *reaches = weight(best);
 563         }
 564         free(weights);
 565         return best;
 566 }
 567
 568 static void read_revisions_from_stdin(struct rev_info *revs)
 569 {
 570         char line[1000];
 571
 572         while (fgets(line, sizeof(line), stdin) != NULL) {
 573                 int len = strlen(line);
 574                 if (len && line[len - 1] == '\n')
 575                         line[--len] = 0;
 576                 if (!len)
 577                         break;
 578                 if (line[0] == '-')
 579                         die("options not supported in --stdin mode");
 580                 if (handle_revision_arg(line, revs, 0, 1))
 581                         die("bad revision '%s'", line);
 582         }
 583 }
 584
 585 int cmd_rev_list(int argc, const char **argv, const char *prefix)
 586 {
 587         struct commit_list *list;
 588         int i;
 589         int read_from_stdin = 0;
 590         int bisect_show_vars = 0;
 591         int bisect_find_all = 0;
 592         int quiet = 0;
 593
 594         git_config(git_default_config, NULL);
 595         init_revisions(&revs, prefix);
 596         revs.abbrev = 0;
 597         revs.commit_format = CMIT_FMT_UNSPECIFIED;
 598         argc = setup_revisions(argc, argv, &revs, NULL);
 599
 600         for (i = 1 ; i < argc; i++) {
 601                 const char *arg = argv[i];
 602
 603                 if (!strcmp(arg, "--header")) {
 604                         revs.verbose_header = 1;
 605                         continue;
 606                 }
 607                 if (!strcmp(arg, "--timestamp")) {
 608                         show_timestamp = 1;
 609                         continue;
 610                 }
 611                 if (!strcmp(arg, "--bisect")) {
 612                         bisect_list = 1;
 613                         continue;
 614                 }
 615                 if (!strcmp(arg, "--bisect-all")) {
 616                         bisect_list = 1;
 617                         bisect_find_all = 1;
 618                         continue;
 619                 }
 620                 if (!strcmp(arg, "--bisect-vars")) {
 621                         bisect_list = 1;
 622                         bisect_show_vars = 1;
 623                         continue;
 624                 }
 625                 if (!strcmp(arg, "--stdin")) {
 626                         if (read_from_stdin++)
 627                                 die("--stdin given twice?");
 628                         read_revisions_from_stdin(&revs);
 629                         continue;
 630                 }
 631                 if (!strcmp(arg, "--quiet")) {
 632                         quiet = 1;
 633                         continue;
 634                 }
 635                 usage(rev_list_usage);
 636
 637         }
 638         if (revs.commit_format != CMIT_FMT_UNSPECIFIED) {
 639                 /* The command line has a --pretty  */
 640                 hdr_termination = '\n';
 641                 if (revs.commit_format == CMIT_FMT_ONELINE)
 642                         header_prefix = "";
 643                 else
 644                         header_prefix = "commit ";
 645         }
 646         else if (revs.verbose_header)
 647                 /* Only --header was specified */
 648                 revs.commit_format = CMIT_FMT_RAW;
 649
 650         list = revs.commits;
 651
 652         if ((!list &&
 653              (!(revs.tag_objects||revs.tree_objects||revs.blob_objects) &&
 654               !revs.pending.nr)) ||
 655             revs.diff)
 656                 usage(rev_list_usage);
 657
 658         save_commit_buffer = revs.verbose_header || revs.grep_filter;
 659         if (bisect_list)
 660                 revs.limited = 1;
 661
 662         if (prepare_revision_walk(&revs))
 663                 die("revision walk setup failed");
 664         if (revs.tree_objects)
 665                 mark_edges_uninteresting(revs.commits, &revs, show_edge);
 666
 667         if (bisect_list) {
 668                 int reaches = reaches, all = all;
 669
 670                 revs.commits = find_bisection(revs.commits, &reaches, &all,
 671                                               bisect_find_all);
 672                 if (bisect_show_vars) {
 673                         int cnt;
 674                         char hex[41];
 675                         if (!revs.commits)
 676                                 return 1;
 677                         /*
 678                          * revs.commits can reach "reaches" commits among
 679                          * "all" commits.  If it is good, then there are
 680                          * (all-reaches) commits left to be bisected.
 681                          * On the other hand, if it is bad, then the set
 682                          * to bisect is "reaches".
 683                          * A bisect set of size N has (N-1) commits further
 684                          * to test, as we already know one bad one.
 685                          */
 686                         cnt = all - reaches;
 687                         if (cnt < reaches)
 688                                 cnt = reaches;
 689                         strcpy(hex, sha1_to_hex(revs.commits->item->object.sha1));
 690
 691                         if (bisect_find_all) {
 692                                 traverse_commit_list(&revs, show_commit, show_object);
 693                                 printf("------\n");
 694                         }
 695
 696                         printf("bisect_rev=%s\n"
 697                                "bisect_nr=%d\n"
 698                                "bisect_good=%d\n"
 699                                "bisect_bad=%d\n"
 700                                "bisect_all=%d\n",
 701                                hex,
 702                                cnt - 1,
 703                                all - reaches - 1,
 704                                reaches - 1,
 705                                all);
 706                         return 0;
 707                 }
 708         }
 709
 710         traverse_commit_list(&revs,
 711                 quiet ? finish_commit : show_commit,
 712                 quiet ? finish_object : show_object);
 713
 714         return 0;
 715 }