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