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
  14 /* bits #0-15 in revision.h */
  15
  16 #define COUNTED         (1u<<16)
  17
  18 static const char rev_list_usage[] =
  19 "git-rev-list [OPTION] <commit-id>... [ -- paths... ]\n"
  20 "  limiting output:\n"
  21 "    --max-count=nr\n"
  22 "    --max-age=epoch\n"
  23 "    --min-age=epoch\n"
  24 "    --sparse\n"
  25 "    --no-merges\n"
  26 "    --remove-empty\n"
  27 "    --all\n"
  28 "    --branches\n"
  29 "    --tags\n"
  30 "    --remotes\n"
  31 "    --stdin\n"
  32 "    --quiet\n"
  33 "  ordering output:\n"
  34 "    --topo-order\n"
  35 "    --date-order\n"
  36 "    --reverse\n"
  37 "  formatting output:\n"
  38 "    --parents\n"
  39 "    --objects | --objects-edge\n"
  40 "    --unpacked\n"
  41 "    --header | --pretty\n"
  42 "    --abbrev=nr | --no-abbrev\n"
  43 "    --abbrev-commit\n"
  44 "    --left-right\n"
  45 "  special purpose:\n"
  46 "    --bisect\n"
  47 "    --bisect-vars\n"
  48 "    --bisect-all"
  49 ;
  50
  51 static struct rev_info revs;
  52
  53 static int bisect_list;
  54 static int show_timestamp;
  55 static int hdr_termination;
  56 static const char *header_prefix;
  57
  58 static void finish_commit(struct commit *commit);
  59 static void show_commit(struct commit *commit)
  60 {
  61         if (show_timestamp)
  62                 printf("%lu ", commit->date);
  63         if (header_prefix)
  64                 fputs(header_prefix, stdout);
  65         if (commit->object.flags & BOUNDARY)
  66                 putchar('-');
  67         else if (commit->object.flags & UNINTERESTING)
  68                 putchar('^');
  69         else if (revs.left_right) {
  70                 if (commit->object.flags & SYMMETRIC_LEFT)
  71                         putchar('<');
  72                 else
  73                         putchar('>');
  74         }
  75         if (revs.abbrev_commit && revs.abbrev)
  76                 fputs(find_unique_abbrev(commit->object.sha1, revs.abbrev),
  77                       stdout);
  78         else
  79                 fputs(sha1_to_hex(commit->object.sha1), stdout);
  80         if (revs.parents) {
  81                 struct commit_list *parents = commit->parents;
  82                 while (parents) {
  83                         printf(" %s", sha1_to_hex(parents->item->object.sha1));
  84                         parents = parents->next;
  85                 }
  86         }
  87         show_decorations(commit);
  88         if (revs.commit_format == CMIT_FMT_ONELINE)
  89                 putchar(' ');
  90         else
  91                 putchar('\n');
  92
  93         if (revs.verbose_header && commit->buffer) {
  94                 struct strbuf buf;
  95                 strbuf_init(&buf, 0);
  96                 pretty_print_commit(revs.commit_format, commit,
  97                                     &buf, revs.abbrev, NULL, NULL,
  98                                     revs.date_mode, 0);
  99                 if (buf.len)
 100                         printf("%s%c", buf.buf, hdr_termination);
 101                 strbuf_release(&buf);
 102         }
 103         maybe_flush_or_die(stdout, "stdout");
 104         finish_commit(commit);
 105 }
 106
 107 static void finish_commit(struct commit *commit)
 108 {
 109         if (commit->parents) {
 110                 free_commit_list(commit->parents);
 111                 commit->parents = NULL;
 112         }
 113         free(commit->buffer);
 114         commit->buffer = NULL;
 115 }
 116
 117 static void finish_object(struct object_array_entry *p)
 118 {
 119         if (p->item->type == OBJ_BLOB && !has_sha1_file(p->item->sha1))
 120                 die("missing blob object '%s'", sha1_to_hex(p->item->sha1));
 121 }
 122
 123 static void show_object(struct object_array_entry *p)
 124 {
 125         /* An object with name "foo\n0000000..." can be used to
 126          * confuse downstream git-pack-objects very badly.
 127          */
 128         const char *ep = strchr(p->name, '\n');
 129
 130         finish_object(p);
 131         if (ep) {
 132                 printf("%s %.*s\n", sha1_to_hex(p->item->sha1),
 133                        (int) (ep - p->name),
 134                        p->name);
 135         }
 136         else
 137                 printf("%s %s\n", sha1_to_hex(p->item->sha1), p->name);
 138 }
 139
 140 static void show_edge(struct commit *commit)
 141 {
 142         printf("-%s\n", sha1_to_hex(commit->object.sha1));
 143 }
 144
 145 /*
 146  * This is a truly stupid algorithm, but it's only
 147  * used for bisection, and we just don't care enough.
 148  *
 149  * We care just barely enough to avoid recursing for
 150  * non-merge entries.
 151  */
 152 static int count_distance(struct commit_list *entry)
 153 {
 154         int nr = 0;
 155
 156         while (entry) {
 157                 struct commit *commit = entry->item;
 158                 struct commit_list *p;
 159
 160                 if (commit->object.flags & (UNINTERESTING | COUNTED))
 161                         break;
 162                 if (!(commit->object.flags & TREESAME))
 163                         nr++;
 164                 commit->object.flags |= COUNTED;
 165                 p = commit->parents;
 166                 entry = p;
 167                 if (p) {
 168                         p = p->next;
 169                         while (p) {
 170                                 nr += count_distance(p);
 171                                 p = p->next;
 172                         }
 173                 }
 174         }
 175
 176         return nr;
 177 }
 178
 179 static void clear_distance(struct commit_list *list)
 180 {
 181         while (list) {
 182                 struct commit *commit = list->item;
 183                 commit->object.flags &= ~COUNTED;
 184                 list = list->next;
 185         }
 186 }
 187
 188 #define DEBUG_BISECT 0
 189
 190 static inline int weight(struct commit_list *elem)
 191 {
 192         return *((int*)(elem->item->util));
 193 }
 194
 195 static inline void weight_set(struct commit_list *elem, int weight)
 196 {
 197         *((int*)(elem->item->util)) = weight;
 198 }
 199
 200 static int count_interesting_parents(struct commit *commit)
 201 {
 202         struct commit_list *p;
 203         int count;
 204
 205         for (count = 0, p = commit->parents; p; p = p->next) {
 206                 if (p->item->object.flags & UNINTERESTING)
 207                         continue;
 208                 count++;
 209         }
 210         return count;
 211 }
 212
 213 static inline int halfway(struct commit_list *p, int nr)
 214 {
 215         /*
 216          * Don't short-cut something we are not going to return!
 217          */
 218         if (p->item->object.flags & TREESAME)
 219                 return 0;
 220         if (DEBUG_BISECT)
 221                 return 0;
 222         /*
 223          * 2 and 3 are halfway of 5.
 224          * 3 is halfway of 6 but 2 and 4 are not.
 225          */
 226         switch (2 * weight(p) - nr) {
 227         case -1: case 0: case 1:
 228                 return 1;
 229         default:
 230                 return 0;
 231         }
 232 }
 233
 234 #if !DEBUG_BISECT
 235 #define show_list(a,b,c,d) do { ; } while (0)
 236 #else
 237 static void show_list(const char *debug, int counted, int nr,
 238                       struct commit_list *list)
 239 {
 240         struct commit_list *p;
 241
 242         fprintf(stderr, "%s (%d/%d)\n", debug, counted, nr);
 243
 244         for (p = list; p; p = p->next) {
 245                 struct commit_list *pp;
 246                 struct commit *commit = p->item;
 247                 unsigned flags = commit->object.flags;
 248                 enum object_type type;
 249                 unsigned long size;
 250                 char *buf = read_sha1_file(commit->object.sha1, &type, &size);
 251                 char *ep, *sp;
 252
 253                 fprintf(stderr, "%c%c%c ",
 254                         (flags & TREESAME) ? ' ' : 'T',
 255                         (flags & UNINTERESTING) ? 'U' : ' ',
 256                         (flags & COUNTED) ? 'C' : ' ');
 257                 if (commit->util)
 258                         fprintf(stderr, "%3d", weight(p));
 259                 else
 260                         fprintf(stderr, "---");
 261                 fprintf(stderr, " %.*s", 8, sha1_to_hex(commit->object.sha1));
 262                 for (pp = commit->parents; pp; pp = pp->next)
 263                         fprintf(stderr, " %.*s", 8,
 264                                 sha1_to_hex(pp->item->object.sha1));
 265
 266                 sp = strstr(buf, "\n\n");
 267                 if (sp) {
 268                         sp += 2;
 269                         for (ep = sp; *ep && *ep != '\n'; ep++)
 270                                 ;
 271                         fprintf(stderr, " %.*s", (int)(ep - sp), sp);
 272                 }
 273                 fprintf(stderr, "\n");
 274         }
 275 }
 276 #endif /* DEBUG_BISECT */
 277
 278 static struct commit_list *best_bisection(struct commit_list *list, int nr)
 279 {
 280         struct commit_list *p, *best;
 281         int best_distance = -1;
 282
 283         best = list;
 284         for (p = list; p; p = p->next) {
 285                 int distance;
 286                 unsigned flags = p->item->object.flags;
 287
 288                 if (flags & TREESAME)
 289                         continue;
 290                 distance = weight(p);
 291                 if (nr - distance < distance)
 292                         distance = nr - distance;
 293                 if (distance > best_distance) {
 294                         best = p;
 295                         best_distance = distance;
 296                 }
 297         }
 298
 299         return best;
 300 }
 301
 302 struct commit_dist {
 303         struct commit *commit;
 304         int distance;
 305 };
 306
 307 static int compare_commit_dist(const void *a_, const void *b_)
 308 {
 309         struct commit_dist *a, *b;
 310
 311         a = (struct commit_dist *)a_;
 312         b = (struct commit_dist *)b_;
 313         if (a->distance != b->distance)
 314                 return b->distance - a->distance; /* desc sort */
 315         return hashcmp(a->commit->object.sha1, b->commit->object.sha1);
 316 }
 317
 318 static struct commit_list *best_bisection_sorted(struct commit_list *list, int nr)
 319 {
 320         struct commit_list *p;
 321         struct commit_dist *array = xcalloc(nr, sizeof(*array));
 322         int cnt, i;
 323
 324         for (p = list, cnt = 0; p; p = p->next) {
 325                 int distance;
 326                 unsigned flags = p->item->object.flags;
 327
 328                 if (flags & TREESAME)
 329                         continue;
 330                 distance = weight(p);
 331                 if (nr - distance < distance)
 332                         distance = nr - distance;
 333                 array[cnt].commit = p->item;
 334                 array[cnt].distance = distance;
 335                 cnt++;
 336         }
 337         qsort(array, cnt, sizeof(*array), compare_commit_dist);
 338         for (p = list, i = 0; i < cnt; i++) {
 339                 struct name_decoration *r = xmalloc(sizeof(*r) + 100);
 340                 struct object *obj = &(array[i].commit->object);
 341
 342                 sprintf(r->name, "dist=%d", array[i].distance);
 343                 r->next = add_decoration(&name_decoration, obj, r);
 344                 p->item = array[i].commit;
 345                 p = p->next;
 346         }
 347         if (p)
 348                 p->next = NULL;
 349         free(array);
 350         return list;
 351 }
 352
 353 /*
 354  * zero or positive weight is the number of interesting commits it can
 355  * reach, including itself.  Especially, weight = 0 means it does not
 356  * reach any tree-changing commits (e.g. just above uninteresting one
 357  * but traversal is with pathspec).
 358  *
 359  * weight = -1 means it has one parent and its distance is yet to
 360  * be computed.
 361  *
 362  * weight = -2 means it has more than one parent and its distance is
 363  * unknown.  After running count_distance() first, they will get zero
 364  * or positive distance.
 365  */
 366 static struct commit_list *do_find_bisection(struct commit_list *list,
 367                                              int nr, int *weights,
 368                                              int find_all)
 369 {
 370         int n, counted;
 371         struct commit_list *p;
 372
 373         counted = 0;
 374
 375         for (n = 0, p = list; p; p = p->next) {
 376                 struct commit *commit = p->item;
 377                 unsigned flags = commit->object.flags;
 378
 379                 p->item->util = &weights[n++];
 380                 switch (count_interesting_parents(commit)) {
 381                 case 0:
 382                         if (!(flags & TREESAME)) {
 383                                 weight_set(p, 1);
 384                                 counted++;
 385                                 show_list("bisection 2 count one",
 386                                           counted, nr, list);
 387                         }
 388                         /*
 389                          * otherwise, it is known not to reach any
 390                          * tree-changing commit and gets weight 0.
 391                          */
 392                         break;
 393                 case 1:
 394                         weight_set(p, -1);
 395                         break;
 396                 default:
 397                         weight_set(p, -2);
 398                         break;
 399                 }
 400         }
 401
 402         show_list("bisection 2 initialize", counted, nr, list);
 403
 404         /*
 405          * If you have only one parent in the resulting set
 406          * then you can reach one commit more than that parent
 407          * can reach.  So we do not have to run the expensive
 408          * count_distance() for single strand of pearls.
 409          *
 410          * However, if you have more than one parents, you cannot
 411          * just add their distance and one for yourself, since
 412          * they usually reach the same ancestor and you would
 413          * end up counting them twice that way.
 414          *
 415          * So we will first count distance of merges the usual
 416          * way, and then fill the blanks using cheaper algorithm.
 417          */
 418         for (p = list; p; p = p->next) {
 419                 if (p->item->object.flags & UNINTERESTING)
 420                         continue;
 421                 if (weight(p) != -2)
 422                         continue;
 423                 weight_set(p, count_distance(p));
 424                 clear_distance(list);
 425
 426                 /* Does it happen to be at exactly half-way? */
 427                 if (!find_all && halfway(p, nr))
 428                         return p;
 429                 counted++;
 430         }
 431
 432         show_list("bisection 2 count_distance", counted, nr, list);
 433
 434         while (counted < nr) {
 435                 for (p = list; p; p = p->next) {
 436                         struct commit_list *q;
 437                         unsigned flags = p->item->object.flags;
 438
 439                         if (0 <= weight(p))
 440                                 continue;
 441                         for (q = p->item->parents; q; q = q->next) {
 442                                 if (q->item->object.flags & UNINTERESTING)
 443                                         continue;
 444                                 if (0 <= weight(q))
 445                                         break;
 446                         }
 447                         if (!q)
 448                                 continue;
 449
 450                         /*
 451                          * weight for p is unknown but q is known.
 452                          * add one for p itself if p is to be counted,
 453                          * otherwise inherit it from q directly.
 454                          */
 455                         if (!(flags & TREESAME)) {
 456                                 weight_set(p, weight(q)+1);
 457                                 counted++;
 458                                 show_list("bisection 2 count one",
 459                                           counted, nr, list);
 460                         }
 461                         else
 462                                 weight_set(p, weight(q));
 463
 464                         /* Does it happen to be at exactly half-way? */
 465                         if (!find_all && halfway(p, nr))
 466                                 return p;
 467                 }
 468         }
 469
 470         show_list("bisection 2 counted all", counted, nr, list);
 471
 472         if (!find_all)
 473                 return best_bisection(list, nr);
 474         else
 475                 return best_bisection_sorted(list, nr);
 476 }
 477
 478 static struct commit_list *find_bisection(struct commit_list *list,
 479                                           int *reaches, int *all,
 480                                           int find_all)
 481 {
 482         int nr, on_list;
 483         struct commit_list *p, *best, *next, *last;
 484         int *weights;
 485
 486         show_list("bisection 2 entry", 0, 0, list);
 487
 488         /*
 489          * Count the number of total and tree-changing items on the
 490          * list, while reversing the list.
 491          */
 492         for (nr = on_list = 0, last = NULL, p = list;
 493              p;
 494              p = next) {
 495                 unsigned flags = p->item->object.flags;
 496
 497                 next = p->next;
 498                 if (flags & UNINTERESTING)
 499                         continue;
 500                 p->next = last;
 501                 last = p;
 502                 if (!(flags & TREESAME))
 503                         nr++;
 504                 on_list++;
 505         }
 506         list = last;
 507         show_list("bisection 2 sorted", 0, nr, list);
 508
 509         *all = nr;
 510         weights = xcalloc(on_list, sizeof(*weights));
 511
 512         /* Do the real work of finding bisection commit. */
 513         best = do_find_bisection(list, nr, weights, find_all);
 514         if (best) {
 515                 if (!find_all)
 516                         best->next = NULL;
 517                 *reaches = weight(best);
 518         }
 519         free(weights);
 520         return best;
 521 }
 522
 523 static void read_revisions_from_stdin(struct rev_info *revs)
 524 {
 525         char line[1000];
 526
 527         while (fgets(line, sizeof(line), stdin) != NULL) {
 528                 int len = strlen(line);
 529                 if (len && line[len - 1] == '\n')
 530                         line[--len] = 0;
 531                 if (!len)
 532                         break;
 533                 if (line[0] == '-')
 534                         die("options not supported in --stdin mode");
 535                 if (handle_revision_arg(line, revs, 0, 1))
 536                         die("bad revision '%s'", line);
 537         }
 538 }
 539
 540 int cmd_rev_list(int argc, const char **argv, const char *prefix)
 541 {
 542         struct commit_list *list;
 543         int i;
 544         int read_from_stdin = 0;
 545         int bisect_show_vars = 0;
 546         int bisect_find_all = 0;
 547         int quiet = 0;
 548
 549         git_config(git_default_config);
 550         init_revisions(&revs, prefix);
 551         revs.abbrev = 0;
 552         revs.commit_format = CMIT_FMT_UNSPECIFIED;
 553         argc = setup_revisions(argc, argv, &revs, NULL);
 554
 555         for (i = 1 ; i < argc; i++) {
 556                 const char *arg = argv[i];
 557
 558                 if (!strcmp(arg, "--header")) {
 559                         revs.verbose_header = 1;
 560                         continue;
 561                 }
 562                 if (!strcmp(arg, "--timestamp")) {
 563                         show_timestamp = 1;
 564                         continue;
 565                 }
 566                 if (!strcmp(arg, "--bisect")) {
 567                         bisect_list = 1;
 568                         continue;
 569                 }
 570                 if (!strcmp(arg, "--bisect-all")) {
 571                         bisect_list = 1;
 572                         bisect_find_all = 1;
 573                         continue;
 574                 }
 575                 if (!strcmp(arg, "--bisect-vars")) {
 576                         bisect_list = 1;
 577                         bisect_show_vars = 1;
 578                         continue;
 579                 }
 580                 if (!strcmp(arg, "--stdin")) {
 581                         if (read_from_stdin++)
 582                                 die("--stdin given twice?");
 583                         read_revisions_from_stdin(&revs);
 584                         continue;
 585                 }
 586                 if (!strcmp(arg, "--quiet")) {
 587                         quiet = 1;
 588                         continue;
 589                 }
 590                 usage(rev_list_usage);
 591
 592         }
 593         if (revs.commit_format != CMIT_FMT_UNSPECIFIED) {
 594                 /* The command line has a --pretty  */
 595                 hdr_termination = '\n';
 596                 if (revs.commit_format == CMIT_FMT_ONELINE)
 597                         header_prefix = "";
 598                 else
 599                         header_prefix = "commit ";
 600         }
 601         else if (revs.verbose_header)
 602                 /* Only --header was specified */
 603                 revs.commit_format = CMIT_FMT_RAW;
 604
 605         list = revs.commits;
 606
 607         if ((!list &&
 608              (!(revs.tag_objects||revs.tree_objects||revs.blob_objects) &&
 609               !revs.pending.nr)) ||
 610             revs.diff)
 611                 usage(rev_list_usage);
 612
 613         save_commit_buffer = revs.verbose_header || revs.grep_filter;
 614         if (bisect_list)
 615                 revs.limited = 1;
 616
 617         if (prepare_revision_walk(&revs))
 618                 die("revision walk setup failed");
 619         if (revs.tree_objects)
 620                 mark_edges_uninteresting(revs.commits, &revs, show_edge);
 621
 622         if (bisect_list) {
 623                 int reaches = reaches, all = all;
 624
 625                 revs.commits = find_bisection(revs.commits, &reaches, &all,
 626                                               bisect_find_all);
 627                 if (bisect_show_vars) {
 628                         int cnt;
 629                         char hex[41];
 630                         if (!revs.commits)
 631                                 return 1;
 632                         /*
 633                          * revs.commits can reach "reaches" commits among
 634                          * "all" commits.  If it is good, then there are
 635                          * (all-reaches) commits left to be bisected.
 636                          * On the other hand, if it is bad, then the set
 637                          * to bisect is "reaches".
 638                          * A bisect set of size N has (N-1) commits further
 639                          * to test, as we already know one bad one.
 640                          */
 641                         cnt = all - reaches;
 642                         if (cnt < reaches)
 643                                 cnt = reaches;
 644                         strcpy(hex, sha1_to_hex(revs.commits->item->object.sha1));
 645
 646                         if (bisect_find_all) {
 647                                 traverse_commit_list(&revs, show_commit, show_object);
 648                                 printf("------\n");
 649                         }
 650
 651                         printf("bisect_rev=%s\n"
 652                                "bisect_nr=%d\n"
 653                                "bisect_good=%d\n"
 654                                "bisect_bad=%d\n"
 655                                "bisect_all=%d\n",
 656                                hex,
 657                                cnt - 1,
 658                                all - reaches - 1,
 659                                reaches - 1,
 660                                all);
 661                         return 0;
 662                 }
 663         }
 664
 665         traverse_commit_list(&revs,
 666                 quiet ? finish_commit : show_commit,
 667                 quiet ? finish_object : show_object);
 668
 669         return 0;
 670 }