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