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