builtin-show-branch.c

   1 #include "cache.h"
   2 #include "commit.h"
   3 #include "refs.h"
   4 #include "builtin.h"
   5 #include "color.h"
   6 #include "parse-options.h"
   7
   8 static const char* show_branch_usage[] = {
   9     "git show-branch [-a|--all] [-r|--remotes] [--topo-order | --date-order] [--current] [--color | --no-color] [--sparse] [--more=<n> | --list | --independent | --merge-base] [--no-name | --sha1-name] [--topics] [<rev> | <glob>]...",
  10     "git show-branch (-g|--reflog)[=<n>[,<base>]] [--list] [<ref>]",
  11     NULL
  12 };
  13
  14 static int showbranch_use_color = -1;
  15 static char column_colors[][COLOR_MAXLEN] = {
  16         GIT_COLOR_RED,
  17         GIT_COLOR_GREEN,
  18         GIT_COLOR_YELLOW,
  19         GIT_COLOR_BLUE,
  20         GIT_COLOR_MAGENTA,
  21         GIT_COLOR_CYAN,
  22 };
  23
  24 #define COLUMN_COLORS_MAX (ARRAY_SIZE(column_colors))
  25
  26 static int default_num;
  27 static int default_alloc;
  28 static const char **default_arg;
  29
  30 #define UNINTERESTING   01
  31
  32 #define REV_SHIFT        2
  33 #define MAX_REVS        (FLAG_BITS - REV_SHIFT) /* should not exceed bits_per_int - REV_SHIFT */
  34
  35 #define DEFAULT_REFLOG  4
  36
  37 static const char *get_color_code(int idx)
  38 {
  39         if (showbranch_use_color)
  40                 return column_colors[idx];
  41         return "";
  42 }
  43
  44 static const char *get_color_reset_code(void)
  45 {
  46         if (showbranch_use_color)
  47                 return GIT_COLOR_RESET;
  48         return "";
  49 }
  50
  51 static struct commit *interesting(struct commit_list *list)
  52 {
  53         while (list) {
  54                 struct commit *commit = list->item;
  55                 list = list->next;
  56                 if (commit->object.flags & UNINTERESTING)
  57                         continue;
  58                 return commit;
  59         }
  60         return NULL;
  61 }
  62
  63 static struct commit *pop_one_commit(struct commit_list **list_p)
  64 {
  65         struct commit *commit;
  66         struct commit_list *list;
  67         list = *list_p;
  68         commit = list->item;
  69         *list_p = list->next;
  70         free(list);
  71         return commit;
  72 }
  73
  74 struct commit_name {
  75         const char *head_name; /* which head's ancestor? */
  76         int generation; /* how many parents away from head_name */
  77 };
  78
  79 /* Name the commit as nth generation ancestor of head_name;
  80  * we count only the first-parent relationship for naming purposes.
  81  */
  82 static void name_commit(struct commit *commit, const char *head_name, int nth)
  83 {
  84         struct commit_name *name;
  85         if (!commit->util)
  86                 commit->util = xmalloc(sizeof(struct commit_name));
  87         name = commit->util;
  88         name->head_name = head_name;
  89         name->generation = nth;
  90 }
  91
  92 /* Parent is the first parent of the commit.  We may name it
  93  * as (n+1)th generation ancestor of the same head_name as
  94  * commit is nth generation ancestor of, if that generation
  95  * number is better than the name it already has.
  96  */
  97 static void name_parent(struct commit *commit, struct commit *parent)
  98 {
  99         struct commit_name *commit_name = commit->util;
 100         struct commit_name *parent_name = parent->util;
 101         if (!commit_name)
 102                 return;
 103         if (!parent_name ||
 104             commit_name->generation + 1 < parent_name->generation)
 105                 name_commit(parent, commit_name->head_name,
 106                             commit_name->generation + 1);
 107 }
 108
 109 static int name_first_parent_chain(struct commit *c)
 110 {
 111         int i = 0;
 112         while (c) {
 113                 struct commit *p;
 114                 if (!c->util)
 115                         break;
 116                 if (!c->parents)
 117                         break;
 118                 p = c->parents->item;
 119                 if (!p->util) {
 120                         name_parent(c, p);
 121                         i++;
 122                 }
 123                 else
 124                         break;
 125                 c = p;
 126         }
 127         return i;
 128 }
 129
 130 static void name_commits(struct commit_list *list,
 131                          struct commit **rev,
 132                          char **ref_name,
 133                          int num_rev)
 134 {
 135         struct commit_list *cl;
 136         struct commit *c;
 137         int i;
 138
 139         /* First give names to the given heads */
 140         for (cl = list; cl; cl = cl->next) {
 141                 c = cl->item;
 142                 if (c->util)
 143                         continue;
 144                 for (i = 0; i < num_rev; i++) {
 145                         if (rev[i] == c) {
 146                                 name_commit(c, ref_name[i], 0);
 147                                 break;
 148                         }
 149                 }
 150         }
 151
 152         /* Then commits on the first parent ancestry chain */
 153         do {
 154                 i = 0;
 155                 for (cl = list; cl; cl = cl->next) {
 156                         i += name_first_parent_chain(cl->item);
 157                 }
 158         } while (i);
 159
 160         /* Finally, any unnamed commits */
 161         do {
 162                 i = 0;
 163                 for (cl = list; cl; cl = cl->next) {
 164                         struct commit_list *parents;
 165                         struct commit_name *n;
 166                         int nth;
 167                         c = cl->item;
 168                         if (!c->util)
 169                                 continue;
 170                         n = c->util;
 171                         parents = c->parents;
 172                         nth = 0;
 173                         while (parents) {
 174                                 struct commit *p = parents->item;
 175                                 char newname[1000], *en;
 176                                 parents = parents->next;
 177                                 nth++;
 178                                 if (p->util)
 179                                         continue;
 180                                 en = newname;
 181                                 switch (n->generation) {
 182                                 case 0:
 183                                         en += sprintf(en, "%s", n->head_name);
 184                                         break;
 185                                 case 1:
 186                                         en += sprintf(en, "%s^", n->head_name);
 187                                         break;
 188                                 default:
 189                                         en += sprintf(en, "%s~%d",
 190                                                 n->head_name, n->generation);
 191                                         break;
 192                                 }
 193                                 if (nth == 1)
 194                                         en += sprintf(en, "^");
 195                                 else
 196                                         en += sprintf(en, "^%d", nth);
 197                                 name_commit(p, xstrdup(newname), 0);
 198                                 i++;
 199                                 name_first_parent_chain(p);
 200                         }
 201                 }
 202         } while (i);
 203 }
 204
 205 static int mark_seen(struct commit *commit, struct commit_list **seen_p)
 206 {
 207         if (!commit->object.flags) {
 208                 commit_list_insert(commit, seen_p);
 209                 return 1;
 210         }
 211         return 0;
 212 }
 213
 214 static void join_revs(struct commit_list **list_p,
 215                       struct commit_list **seen_p,
 216                       int num_rev, int extra)
 217 {
 218         int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 219         int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 220
 221         while (*list_p) {
 222                 struct commit_list *parents;
 223                 int still_interesting = !!interesting(*list_p);
 224                 struct commit *commit = pop_one_commit(list_p);
 225                 int flags = commit->object.flags & all_mask;
 226
 227                 if (!still_interesting && extra <= 0)
 228                         break;
 229
 230                 mark_seen(commit, seen_p);
 231                 if ((flags & all_revs) == all_revs)
 232                         flags |= UNINTERESTING;
 233                 parents = commit->parents;
 234
 235                 while (parents) {
 236                         struct commit *p = parents->item;
 237                         int this_flag = p->object.flags;
 238                         parents = parents->next;
 239                         if ((this_flag & flags) == flags)
 240                                 continue;
 241                         if (!p->object.parsed)
 242                                 parse_commit(p);
 243                         if (mark_seen(p, seen_p) && !still_interesting)
 244                                 extra--;
 245                         p->object.flags |= flags;
 246                         insert_by_date(p, list_p);
 247                 }
 248         }
 249
 250         /*
 251          * Postprocess to complete well-poisoning.
 252          *
 253          * At this point we have all the commits we have seen in
 254          * seen_p list.  Mark anything that can be reached from
 255          * uninteresting commits not interesting.
 256          */
 257         for (;;) {
 258                 int changed = 0;
 259                 struct commit_list *s;
 260                 for (s = *seen_p; s; s = s->next) {
 261                         struct commit *c = s->item;
 262                         struct commit_list *parents;
 263
 264                         if (((c->object.flags & all_revs) != all_revs) &&
 265                             !(c->object.flags & UNINTERESTING))
 266                                 continue;
 267
 268                         /* The current commit is either a merge base or
 269                          * already uninteresting one.  Mark its parents
 270                          * as uninteresting commits _only_ if they are
 271                          * already parsed.  No reason to find new ones
 272                          * here.
 273                          */
 274                         parents = c->parents;
 275                         while (parents) {
 276                                 struct commit *p = parents->item;
 277                                 parents = parents->next;
 278                                 if (!(p->object.flags & UNINTERESTING)) {
 279                                         p->object.flags |= UNINTERESTING;
 280                                         changed = 1;
 281                                 }
 282                         }
 283                 }
 284                 if (!changed)
 285                         break;
 286         }
 287 }
 288
 289 static void show_one_commit(struct commit *commit, int no_name)
 290 {
 291         struct strbuf pretty = STRBUF_INIT;
 292         const char *pretty_str = "(unavailable)";
 293         struct commit_name *name = commit->util;
 294
 295         if (commit->object.parsed) {
 296                 pretty_print_commit(CMIT_FMT_ONELINE, commit,
 297                                     &pretty, 0, NULL, NULL, 0, 0);
 298                 pretty_str = pretty.buf;
 299         }
 300         if (!prefixcmp(pretty_str, "[PATCH] "))
 301                 pretty_str += 8;
 302
 303         if (!no_name) {
 304                 if (name && name->head_name) {
 305                         printf("[%s", name->head_name);
 306                         if (name->generation) {
 307                                 if (name->generation == 1)
 308                                         printf("^");
 309                                 else
 310                                         printf("~%d", name->generation);
 311                         }
 312                         printf("] ");
 313                 }
 314                 else
 315                         printf("[%s] ",
 316                                find_unique_abbrev(commit->object.sha1, 7));
 317         }
 318         puts(pretty_str);
 319         strbuf_release(&pretty);
 320 }
 321
 322 static char *ref_name[MAX_REVS + 1];
 323 static int ref_name_cnt;
 324
 325 static const char *find_digit_prefix(const char *s, int *v)
 326 {
 327         const char *p;
 328         int ver;
 329         char ch;
 330
 331         for (p = s, ver = 0;
 332              '0' <= (ch = *p) && ch <= '9';
 333              p++)
 334                 ver = ver * 10 + ch - '0';
 335         *v = ver;
 336         return p;
 337 }
 338
 339
 340 static int version_cmp(const char *a, const char *b)
 341 {
 342         while (1) {
 343                 int va, vb;
 344
 345                 a = find_digit_prefix(a, &va);
 346                 b = find_digit_prefix(b, &vb);
 347                 if (va != vb)
 348                         return va - vb;
 349
 350                 while (1) {
 351                         int ca = *a;
 352                         int cb = *b;
 353                         if ('0' <= ca && ca <= '9')
 354                                 ca = 0;
 355                         if ('0' <= cb && cb <= '9')
 356                                 cb = 0;
 357                         if (ca != cb)
 358                                 return ca - cb;
 359                         if (!ca)
 360                                 break;
 361                         a++;
 362                         b++;
 363                 }
 364                 if (!*a && !*b)
 365                         return 0;
 366         }
 367 }
 368
 369 static int compare_ref_name(const void *a_, const void *b_)
 370 {
 371         const char * const*a = a_, * const*b = b_;
 372         return version_cmp(*a, *b);
 373 }
 374
 375 static void sort_ref_range(int bottom, int top)
 376 {
 377         qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
 378               compare_ref_name);
 379 }
 380
 381 static int append_ref(const char *refname, const unsigned char *sha1,
 382                       int allow_dups)
 383 {
 384         struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 385         int i;
 386
 387         if (!commit)
 388                 return 0;
 389
 390         if (!allow_dups) {
 391                 /* Avoid adding the same thing twice */
 392                 for (i = 0; i < ref_name_cnt; i++)
 393                         if (!strcmp(refname, ref_name[i]))
 394                                 return 0;
 395         }
 396         if (MAX_REVS <= ref_name_cnt) {
 397                 warning("ignoring %s; cannot handle more than %d refs",
 398                         refname, MAX_REVS);
 399                 return 0;
 400         }
 401         ref_name[ref_name_cnt++] = xstrdup(refname);
 402         ref_name[ref_name_cnt] = NULL;
 403         return 0;
 404 }
 405
 406 static int append_head_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 407 {
 408         unsigned char tmp[20];
 409         int ofs = 11;
 410         if (prefixcmp(refname, "refs/heads/"))
 411                 return 0;
 412         /* If both heads/foo and tags/foo exists, get_sha1 would
 413          * get confused.
 414          */
 415         if (get_sha1(refname + ofs, tmp) || hashcmp(tmp, sha1))
 416                 ofs = 5;
 417         return append_ref(refname + ofs, sha1, 0);
 418 }
 419
 420 static int append_remote_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 421 {
 422         unsigned char tmp[20];
 423         int ofs = 13;
 424         if (prefixcmp(refname, "refs/remotes/"))
 425                 return 0;
 426         /* If both heads/foo and tags/foo exists, get_sha1 would
 427          * get confused.
 428          */
 429         if (get_sha1(refname + ofs, tmp) || hashcmp(tmp, sha1))
 430                 ofs = 5;
 431         return append_ref(refname + ofs, sha1, 0);
 432 }
 433
 434 static int append_tag_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 435 {
 436         if (prefixcmp(refname, "refs/tags/"))
 437                 return 0;
 438         return append_ref(refname + 5, sha1, 0);
 439 }
 440
 441 static const char *match_ref_pattern = NULL;
 442 static int match_ref_slash = 0;
 443 static int count_slash(const char *s)
 444 {
 445         int cnt = 0;
 446         while (*s)
 447                 if (*s++ == '/')
 448                         cnt++;
 449         return cnt;
 450 }
 451
 452 static int append_matching_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 453 {
 454         /* we want to allow pattern hold/<asterisk> to show all
 455          * branches under refs/heads/hold/, and v0.99.9? to show
 456          * refs/tags/v0.99.9a and friends.
 457          */
 458         const char *tail;
 459         int slash = count_slash(refname);
 460         for (tail = refname; *tail && match_ref_slash < slash; )
 461                 if (*tail++ == '/')
 462                         slash--;
 463         if (!*tail)
 464                 return 0;
 465         if (fnmatch(match_ref_pattern, tail, 0))
 466                 return 0;
 467         if (!prefixcmp(refname, "refs/heads/"))
 468                 return append_head_ref(refname, sha1, flag, cb_data);
 469         if (!prefixcmp(refname, "refs/tags/"))
 470                 return append_tag_ref(refname, sha1, flag, cb_data);
 471         return append_ref(refname, sha1, 0);
 472 }
 473
 474 static void snarf_refs(int head, int remotes)
 475 {
 476         if (head) {
 477                 int orig_cnt = ref_name_cnt;
 478                 for_each_ref(append_head_ref, NULL);
 479                 sort_ref_range(orig_cnt, ref_name_cnt);
 480         }
 481         if (remotes) {
 482                 int orig_cnt = ref_name_cnt;
 483                 for_each_ref(append_remote_ref, NULL);
 484                 sort_ref_range(orig_cnt, ref_name_cnt);
 485         }
 486 }
 487
 488 static int rev_is_head(char *head, int headlen, char *name,
 489                        unsigned char *head_sha1, unsigned char *sha1)
 490 {
 491         if ((!head[0]) ||
 492             (head_sha1 && sha1 && hashcmp(head_sha1, sha1)))
 493                 return 0;
 494         if (!prefixcmp(head, "refs/heads/"))
 495                 head += 11;
 496         if (!prefixcmp(name, "refs/heads/"))
 497                 name += 11;
 498         else if (!prefixcmp(name, "heads/"))
 499                 name += 6;
 500         return !strcmp(head, name);
 501 }
 502
 503 static int show_merge_base(struct commit_list *seen, int num_rev)
 504 {
 505         int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 506         int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 507         int exit_status = 1;
 508
 509         while (seen) {
 510                 struct commit *commit = pop_one_commit(&seen);
 511                 int flags = commit->object.flags & all_mask;
 512                 if (!(flags & UNINTERESTING) &&
 513                     ((flags & all_revs) == all_revs)) {
 514                         puts(sha1_to_hex(commit->object.sha1));
 515                         exit_status = 0;
 516                         commit->object.flags |= UNINTERESTING;
 517                 }
 518         }
 519         return exit_status;
 520 }
 521
 522 static int show_independent(struct commit **rev,
 523                             int num_rev,
 524                             char **ref_name,
 525                             unsigned int *rev_mask)
 526 {
 527         int i;
 528
 529         for (i = 0; i < num_rev; i++) {
 530                 struct commit *commit = rev[i];
 531                 unsigned int flag = rev_mask[i];
 532
 533                 if (commit->object.flags == flag)
 534                         puts(sha1_to_hex(commit->object.sha1));
 535                 commit->object.flags |= UNINTERESTING;
 536         }
 537         return 0;
 538 }
 539
 540 static void append_one_rev(const char *av)
 541 {
 542         unsigned char revkey[20];
 543         if (!get_sha1(av, revkey)) {
 544                 append_ref(av, revkey, 0);
 545                 return;
 546         }
 547         if (strchr(av, '*') || strchr(av, '?') || strchr(av, '[')) {
 548                 /* glob style match */
 549                 int saved_matches = ref_name_cnt;
 550                 match_ref_pattern = av;
 551                 match_ref_slash = count_slash(av);
 552                 for_each_ref(append_matching_ref, NULL);
 553                 if (saved_matches == ref_name_cnt &&
 554                     ref_name_cnt < MAX_REVS)
 555                         error("no matching refs with %s", av);
 556                 if (saved_matches + 1 < ref_name_cnt)
 557                         sort_ref_range(saved_matches, ref_name_cnt);
 558                 return;
 559         }
 560         die("bad sha1 reference %s", av);
 561 }
 562
 563 static int git_show_branch_config(const char *var, const char *value, void *cb)
 564 {
 565         if (!strcmp(var, "showbranch.default")) {
 566                 if (!value)
 567                         return config_error_nonbool(var);
 568                 if (default_alloc <= default_num + 1) {
 569                         default_alloc = default_alloc * 3 / 2 + 20;
 570                         default_arg = xrealloc(default_arg, sizeof *default_arg * default_alloc);
 571                 }
 572                 default_arg[default_num++] = xstrdup(value);
 573                 default_arg[default_num] = NULL;
 574                 return 0;
 575         }
 576
 577         if (!strcmp(var, "color.showbranch")) {
 578                 showbranch_use_color = git_config_colorbool(var, value, -1);
 579                 return 0;
 580         }
 581
 582         return git_color_default_config(var, value, cb);
 583 }
 584
 585 static int omit_in_dense(struct commit *commit, struct commit **rev, int n)
 586 {
 587         /* If the commit is tip of the named branches, do not
 588          * omit it.
 589          * Otherwise, if it is a merge that is reachable from only one
 590          * tip, it is not that interesting.
 591          */
 592         int i, flag, count;
 593         for (i = 0; i < n; i++)
 594                 if (rev[i] == commit)
 595                         return 0;
 596         flag = commit->object.flags;
 597         for (i = count = 0; i < n; i++) {
 598                 if (flag & (1u << (i + REV_SHIFT)))
 599                         count++;
 600         }
 601         if (count == 1)
 602                 return 1;
 603         return 0;
 604 }
 605
 606 static int reflog = 0;
 607
 608 static int parse_reflog_param(const struct option *opt, const char *arg,
 609                               int unset)
 610 {
 611         char *ep;
 612         const char **base = (const char **)opt->value;
 613         if (!arg)
 614                 arg = "";
 615         reflog = strtoul(arg, &ep, 10);
 616         if (*ep == ',')
 617                 *base = ep + 1;
 618         else if (*ep)
 619                 return error("unrecognized reflog param '%s'", arg);
 620         else
 621                 *base = NULL;
 622         if (reflog <= 0)
 623                 reflog = DEFAULT_REFLOG;
 624         return 0;
 625 }
 626
 627 int cmd_show_branch(int ac, const char **av, const char *prefix)
 628 {
 629         struct commit *rev[MAX_REVS], *commit;
 630         char *reflog_msg[MAX_REVS];
 631         struct commit_list *list = NULL, *seen = NULL;
 632         unsigned int rev_mask[MAX_REVS];
 633         int num_rev, i, extra = 0;
 634         int all_heads = 0, all_remotes = 0;
 635         int all_mask, all_revs;
 636         int lifo = 1;
 637         char head[128];
 638         const char *head_p;
 639         int head_len;
 640         unsigned char head_sha1[20];
 641         int merge_base = 0;
 642         int independent = 0;
 643         int no_name = 0;
 644         int sha1_name = 0;
 645         int shown_merge_point = 0;
 646         int with_current_branch = 0;
 647         int head_at = -1;
 648         int topics = 0;
 649         int dense = 1;
 650         const char *reflog_base = NULL;
 651         struct option builtin_show_branch_options[] = {
 652                 OPT_BOOLEAN('a', "all", &all_heads,
 653                             "show remote-tracking and local branches"),
 654                 OPT_BOOLEAN('r', "remotes", &all_remotes,
 655                             "show remote-tracking branches"),
 656                 OPT_BOOLEAN(0, "color", &showbranch_use_color,
 657                             "color '*!+-' corresponding to the branch"),
 658                 { OPTION_INTEGER, 0, "more", &extra, "n",
 659                             "show <n> more commits after the common ancestor",
 660                             PARSE_OPT_OPTARG, NULL, (intptr_t)1 },
 661                 OPT_SET_INT(0, "list", &extra, "synonym to more=-1", -1),
 662                 OPT_BOOLEAN(0, "no-name", &no_name, "suppress naming strings"),
 663                 OPT_BOOLEAN(0, "current", &with_current_branch,
 664                             "include the current branch"),
 665                 OPT_BOOLEAN(0, "sha1-name", &sha1_name,
 666                             "name commits with their object names"),
 667                 OPT_BOOLEAN(0, "merge-base", &merge_base,
 668                             "show possible merge bases"),
 669                 OPT_BOOLEAN(0, "independent", &independent,
 670                             "show refs unreachable from any other ref"),
 671                 OPT_BOOLEAN(0, "topo-order", &lifo,
 672                             "show commits in topological order"),
 673                 OPT_BOOLEAN(0, "topics", &topics,
 674                             "show only commits not on the first branch"),
 675                 OPT_SET_INT(0, "sparse", &dense,
 676                             "show merges reachable from only one tip", 0),
 677                 OPT_SET_INT(0, "date-order", &lifo,
 678                             "show commits where no parent comes before its "
 679                             "children", 0),
 680                 { OPTION_CALLBACK, 'g', "reflog", &reflog_base, "<n>[,<base>]",
 681                             "show <n> most recent ref-log entries starting at "
 682                             "base",
 683                             PARSE_OPT_OPTARG | PARSE_OPT_LITERAL_ARGHELP,
 684                             parse_reflog_param },
 685                 OPT_END()
 686         };
 687
 688         git_config(git_show_branch_config, NULL);
 689
 690         if (showbranch_use_color == -1)
 691                 showbranch_use_color = git_use_color_default;
 692
 693         /* If nothing is specified, try the default first */
 694         if (ac == 1 && default_num) {
 695                 ac = default_num + 1;
 696                 av = default_arg - 1; /* ick; we would not address av[0] */
 697         }
 698
 699         ac = parse_options(ac, av, prefix, builtin_show_branch_options,
 700                            show_branch_usage, PARSE_OPT_STOP_AT_NON_OPTION);
 701         if (all_heads)
 702                 all_remotes = 1;
 703
 704         if (extra || reflog) {
 705                 /* "listing" mode is incompatible with
 706                  * independent nor merge-base modes.
 707                  */
 708                 if (independent || merge_base)
 709                         usage_with_options(show_branch_usage,
 710                                            builtin_show_branch_options);
 711                 if (reflog && ((0 < extra) || all_heads || all_remotes))
 712                         /*
 713                          * Asking for --more in reflog mode does not
 714                          * make sense.  --list is Ok.
 715                          *
 716                          * Also --all and --remotes do not make sense either.
 717                          */
 718                         die("--reflog is incompatible with --all, --remotes, "
 719                             "--independent or --merge-base");
 720         }
 721
 722         /* If nothing is specified, show all branches by default */
 723         if (ac + all_heads + all_remotes == 0)
 724                 all_heads = 1;
 725
 726         if (reflog) {
 727                 unsigned char sha1[20];
 728                 char nth_desc[256];
 729                 char *ref;
 730                 int base = 0;
 731
 732                 if (ac == 0) {
 733                         static const char *fake_av[2];
 734                         const char *refname;
 735
 736                         refname = resolve_ref("HEAD", sha1, 1, NULL);
 737                         fake_av[0] = xstrdup(refname);
 738                         fake_av[1] = NULL;
 739                         av = fake_av;
 740                         ac = 1;
 741                 }
 742                 if (ac != 1)
 743                         die("--reflog option needs one branch name");
 744
 745                 if (MAX_REVS < reflog)
 746                         die("Only %d entries can be shown at one time.",
 747                             MAX_REVS);
 748                 if (!dwim_ref(*av, strlen(*av), sha1, &ref))
 749                         die("No such ref %s", *av);
 750
 751                 /* Has the base been specified? */
 752                 if (reflog_base) {
 753                         char *ep;
 754                         base = strtoul(reflog_base, &ep, 10);
 755                         if (*ep) {
 756                                 /* Ah, that is a date spec... */
 757                                 unsigned long at;
 758                                 at = approxidate(reflog_base);
 759                                 read_ref_at(ref, at, -1, sha1, NULL,
 760                                             NULL, NULL, &base);
 761                         }
 762                 }
 763
 764                 for (i = 0; i < reflog; i++) {
 765                         char *logmsg, *m;
 766                         const char *msg;
 767                         unsigned long timestamp;
 768                         int tz;
 769
 770                         if (read_ref_at(ref, 0, base+i, sha1, &logmsg,
 771                                         &timestamp, &tz, NULL)) {
 772                                 reflog = i;
 773                                 break;
 774                         }
 775                         msg = strchr(logmsg, '\t');
 776                         if (!msg)
 777                                 msg = "(none)";
 778                         else
 779                                 msg++;
 780                         m = xmalloc(strlen(msg) + 200);
 781                         sprintf(m, "(%s) %s",
 782                                 show_date(timestamp, tz, 1),
 783                                 msg);
 784                         reflog_msg[i] = m;
 785                         free(logmsg);
 786                         sprintf(nth_desc, "%s@{%d}", *av, base+i);
 787                         append_ref(nth_desc, sha1, 1);
 788                 }
 789         }
 790         else if (all_heads + all_remotes)
 791                 snarf_refs(all_heads, all_remotes);
 792         else {
 793                 while (0 < ac) {
 794                         append_one_rev(*av);
 795                         ac--; av++;
 796                 }
 797         }
 798
 799         head_p = resolve_ref("HEAD", head_sha1, 1, NULL);
 800         if (head_p) {
 801                 head_len = strlen(head_p);
 802                 memcpy(head, head_p, head_len + 1);
 803         }
 804         else {
 805                 head_len = 0;
 806                 head[0] = 0;
 807         }
 808
 809         if (with_current_branch && head_p) {
 810                 int has_head = 0;
 811                 for (i = 0; !has_head && i < ref_name_cnt; i++) {
 812                         /* We are only interested in adding the branch
 813                          * HEAD points at.
 814                          */
 815                         if (rev_is_head(head,
 816                                         head_len,
 817                                         ref_name[i],
 818                                         head_sha1, NULL))
 819                                 has_head++;
 820                 }
 821                 if (!has_head) {
 822                         int offset = !prefixcmp(head, "refs/heads/") ? 11 : 0;
 823                         append_one_rev(head + offset);
 824                 }
 825         }
 826
 827         if (!ref_name_cnt) {
 828                 fprintf(stderr, "No revs to be shown.\n");
 829                 exit(0);
 830         }
 831
 832         for (num_rev = 0; ref_name[num_rev]; num_rev++) {
 833                 unsigned char revkey[20];
 834                 unsigned int flag = 1u << (num_rev + REV_SHIFT);
 835
 836                 if (MAX_REVS <= num_rev)
 837                         die("cannot handle more than %d revs.", MAX_REVS);
 838                 if (get_sha1(ref_name[num_rev], revkey))
 839                         die("'%s' is not a valid ref.", ref_name[num_rev]);
 840                 commit = lookup_commit_reference(revkey);
 841                 if (!commit)
 842                         die("cannot find commit %s (%s)",
 843                             ref_name[num_rev], revkey);
 844                 parse_commit(commit);
 845                 mark_seen(commit, &seen);
 846
 847                 /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
 848                  * and so on.  REV_SHIFT bits from bit 0 are used for
 849                  * internal bookkeeping.
 850                  */
 851                 commit->object.flags |= flag;
 852                 if (commit->object.flags == flag)
 853                         insert_by_date(commit, &list);
 854                 rev[num_rev] = commit;
 855         }
 856         for (i = 0; i < num_rev; i++)
 857                 rev_mask[i] = rev[i]->object.flags;
 858
 859         if (0 <= extra)
 860                 join_revs(&list, &seen, num_rev, extra);
 861
 862         sort_by_date(&seen);
 863
 864         if (merge_base)
 865                 return show_merge_base(seen, num_rev);
 866
 867         if (independent)
 868                 return show_independent(rev, num_rev, ref_name, rev_mask);
 869
 870         /* Show list; --more=-1 means list-only */
 871         if (1 < num_rev || extra < 0) {
 872                 for (i = 0; i < num_rev; i++) {
 873                         int j;
 874                         int is_head = rev_is_head(head,
 875                                                   head_len,
 876                                                   ref_name[i],
 877                                                   head_sha1,
 878                                                   rev[i]->object.sha1);
 879                         if (extra < 0)
 880                                 printf("%c [%s] ",
 881                                        is_head ? '*' : ' ', ref_name[i]);
 882                         else {
 883                                 for (j = 0; j < i; j++)
 884                                         putchar(' ');
 885                                 printf("%s%c%s [%s] ",
 886                                        get_color_code(i % COLUMN_COLORS_MAX),
 887                                        is_head ? '*' : '!',
 888                                        get_color_reset_code(), ref_name[i]);
 889                         }
 890
 891                         if (!reflog) {
 892                                 /* header lines never need name */
 893                                 show_one_commit(rev[i], 1);
 894                         }
 895                         else
 896                                 puts(reflog_msg[i]);
 897
 898                         if (is_head)
 899                                 head_at = i;
 900                 }
 901                 if (0 <= extra) {
 902                         for (i = 0; i < num_rev; i++)
 903                                 putchar('-');
 904                         putchar('\n');
 905                 }
 906         }
 907         if (extra < 0)
 908                 exit(0);
 909
 910         /* Sort topologically */
 911         sort_in_topological_order(&seen, lifo);
 912
 913         /* Give names to commits */
 914         if (!sha1_name && !no_name)
 915                 name_commits(seen, rev, ref_name, num_rev);
 916
 917         all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 918         all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 919
 920         while (seen) {
 921                 struct commit *commit = pop_one_commit(&seen);
 922                 int this_flag = commit->object.flags;
 923                 int is_merge_point = ((this_flag & all_revs) == all_revs);
 924
 925                 shown_merge_point |= is_merge_point;
 926
 927                 if (1 < num_rev) {
 928                         int is_merge = !!(commit->parents &&
 929                                           commit->parents->next);
 930                         if (topics &&
 931                             !is_merge_point &&
 932                             (this_flag & (1u << REV_SHIFT)))
 933                                 continue;
 934                         if (dense && is_merge &&
 935                             omit_in_dense(commit, rev, num_rev))
 936                                 continue;
 937                         for (i = 0; i < num_rev; i++) {
 938                                 int mark;
 939                                 if (!(this_flag & (1u << (i + REV_SHIFT))))
 940                                         mark = ' ';
 941                                 else if (is_merge)
 942                                         mark = '-';
 943                                 else if (i == head_at)
 944                                         mark = '*';
 945                                 else
 946                                         mark = '+';
 947                                 printf("%s%c%s",
 948                                        get_color_code(i % COLUMN_COLORS_MAX),
 949                                        mark, get_color_reset_code());
 950                         }
 951                         putchar(' ');
 952                 }
 953                 show_one_commit(commit, no_name);
 954
 955                 if (shown_merge_point && --extra < 0)
 956                         break;
 957         }
 958         return 0;
 959 }