show-branch.c

   1 #include <stdlib.h>
   2 #include <fnmatch.h>
   3 #include "cache.h"
   4 #include "commit.h"
   5 #include "refs.h"
   6
   7 static const char show_branch_usage[] =
   8 "git-show-branch [--all] [--heads] [--tags] [--topo-order] [--more=count | --list | --independent | --merge-base ] [<refs>...]";
   9
  10 static int default_num = 0;
  11 static int default_alloc = 0;
  12 static char **default_arg = NULL;
  13
  14 #define UNINTERESTING   01
  15
  16 #define REV_SHIFT        2
  17 #define MAX_REVS        29 /* should not exceed bits_per_int - REV_SHIFT */
  18
  19 static struct commit *interesting(struct commit_list *list)
  20 {
  21         while (list) {
  22                 struct commit *commit = list->item;
  23                 list = list->next;
  24                 if (commit->object.flags & UNINTERESTING)
  25                         continue;
  26                 return commit;
  27         }
  28         return NULL;
  29 }
  30
  31 static struct commit *pop_one_commit(struct commit_list **list_p)
  32 {
  33         struct commit *commit;
  34         struct commit_list *list;
  35         list = *list_p;
  36         commit = list->item;
  37         *list_p = list->next;
  38         free(list);
  39         return commit;
  40 }
  41
  42 struct commit_name {
  43         const char *head_name; /* which head's ancestor? */
  44         int generation; /* how many parents away from head_name */
  45 };
  46
  47 /* Name the commit as nth generation ancestor of head_name;
  48  * we count only the first-parent relationship for naming purposes.
  49  */
  50 static void name_commit(struct commit *commit, const char *head_name, int nth)
  51 {
  52         struct commit_name *name;
  53         if (!commit->object.util)
  54                 commit->object.util = xmalloc(sizeof(struct commit_name));
  55         name = commit->object.util;
  56         name->head_name = head_name;
  57         name->generation = nth;
  58 }
  59
  60 /* Parent is the first parent of the commit.  We may name it
  61  * as (n+1)th generation ancestor of the same head_name as
  62  * commit is nth generation ancestor of, if that generation
  63  * number is better than the name it already has.
  64  */
  65 static void name_parent(struct commit *commit, struct commit *parent)
  66 {
  67         struct commit_name *commit_name = commit->object.util;
  68         struct commit_name *parent_name = parent->object.util;
  69         if (!commit_name)
  70                 return;
  71         if (!parent_name ||
  72             commit_name->generation + 1 < parent_name->generation)
  73                 name_commit(parent, commit_name->head_name,
  74                             commit_name->generation + 1);
  75 }
  76
  77 static int name_first_parent_chain(struct commit *c)
  78 {
  79         int i = 0;
  80         while (c) {
  81                 struct commit *p;
  82                 if (!c->object.util)
  83                         break;
  84                 if (!c->parents)
  85                         break;
  86                 p = c->parents->item;
  87                 if (!p->object.util) {
  88                         name_parent(c, p);
  89                         i++;
  90                 }
  91                 c = p;
  92         }
  93         return i;
  94 }
  95
  96 static void name_commits(struct commit_list *list,
  97                          struct commit **rev,
  98                          char **ref_name,
  99                          int num_rev)
 100 {
 101         struct commit_list *cl;
 102         struct commit *c;
 103         int i;
 104
 105         /* First give names to the given heads */
 106         for (cl = list; cl; cl = cl->next) {
 107                 c = cl->item;
 108                 if (c->object.util)
 109                         continue;
 110                 for (i = 0; i < num_rev; i++) {
 111                         if (rev[i] == c) {
 112                                 name_commit(c, ref_name[i], 0);
 113                                 break;
 114                         }
 115                 }
 116         }
 117
 118         /* Then commits on the first parent ancestry chain */
 119         do {
 120                 i = 0;
 121                 for (cl = list; cl; cl = cl->next) {
 122                         i += name_first_parent_chain(cl->item);
 123                 }
 124         } while (i);
 125
 126         /* Finally, any unnamed commits */
 127         do {
 128                 i = 0;
 129                 for (cl = list; cl; cl = cl->next) {
 130                         struct commit_list *parents;
 131                         struct commit_name *n;
 132                         int nth;
 133                         c = cl->item;
 134                         if (!c->object.util)
 135                                 continue;
 136                         n = c->object.util;
 137                         parents = c->parents;
 138                         nth = 0;
 139                         while (parents) {
 140                                 struct commit *p = parents->item;
 141                                 char newname[1000], *en;
 142                                 parents = parents->next;
 143                                 nth++;
 144                                 if (p->object.util)
 145                                         continue;
 146                                 en = newname;
 147                                 switch (n->generation) {
 148                                 case 0:
 149                                         en += sprintf(en, "%s", n->head_name);
 150                                         break;
 151                                 case 1:
 152                                         en += sprintf(en, "%s^", n->head_name);
 153                                         break;
 154                                 default:
 155                                         en += sprintf(en, "%s~%d",
 156                                                 n->head_name, n->generation);
 157                                         break;
 158                                 }
 159                                 if (nth == 1)
 160                                         en += sprintf(en, "^");
 161                                 else
 162                                         en += sprintf(en, "^%d", nth);
 163                                 name_commit(p, strdup(newname), 0);
 164                                 i++;
 165                                 name_first_parent_chain(p);
 166                         }
 167                 }
 168         } while (i);
 169 }
 170
 171 static int mark_seen(struct commit *commit, struct commit_list **seen_p)
 172 {
 173         if (!commit->object.flags) {
 174                 insert_by_date(commit, seen_p);
 175                 return 1;
 176         }
 177         return 0;
 178 }
 179
 180 static void join_revs(struct commit_list **list_p,
 181                       struct commit_list **seen_p,
 182                       int num_rev, int extra)
 183 {
 184         int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 185         int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 186
 187         while (*list_p) {
 188                 struct commit_list *parents;
 189                 int still_interesting = !!interesting(*list_p);
 190                 struct commit *commit = pop_one_commit(list_p);
 191                 int flags = commit->object.flags & all_mask;
 192
 193                 if (!still_interesting && extra <= 0)
 194                         break;
 195
 196                 mark_seen(commit, seen_p);
 197                 if ((flags & all_revs) == all_revs)
 198                         flags |= UNINTERESTING;
 199                 parents = commit->parents;
 200
 201                 while (parents) {
 202                         struct commit *p = parents->item;
 203                         int this_flag = p->object.flags;
 204                         parents = parents->next;
 205                         if ((this_flag & flags) == flags)
 206                                 continue;
 207                         if (!p->object.parsed)
 208                                 parse_commit(p);
 209                         if (mark_seen(p, seen_p) && !still_interesting)
 210                                 extra--;
 211                         p->object.flags |= flags;
 212                         insert_by_date(p, list_p);
 213                 }
 214         }
 215
 216         /*
 217          * Postprocess to complete well-poisoning.
 218          *
 219          * At this point we have all the commits we have seen in
 220          * seen_p list (which happens to be sorted chronologically but
 221          * it does not really matter).  Mark anything that can be
 222          * reached from uninteresting commits not interesting.
 223          */
 224         for (;;) {
 225                 int changed = 0;
 226                 struct commit_list *s;
 227                 for (s = *seen_p; s; s = s->next) {
 228                         struct commit *c = s->item;
 229                         struct commit_list *parents;
 230
 231                         if (((c->object.flags & all_revs) != all_revs) &&
 232                             !(c->object.flags & UNINTERESTING))
 233                                 continue;
 234
 235                         /* The current commit is either a merge base or
 236                          * already uninteresting one.  Mark its parents
 237                          * as uninteresting commits _only_ if they are
 238                          * already parsed.  No reason to find new ones
 239                          * here.
 240                          */
 241                         parents = c->parents;
 242                         while (parents) {
 243                                 struct commit *p = parents->item;
 244                                 parents = parents->next;
 245                                 if (!(p->object.flags & UNINTERESTING)) {
 246                                         p->object.flags |= UNINTERESTING;
 247                                         changed = 1;
 248                                 }
 249                         }
 250                 }
 251                 if (!changed)
 252                         break;
 253         }
 254 }
 255
 256 static void show_one_commit(struct commit *commit, int no_name)
 257 {
 258         char pretty[256], *cp;
 259         struct commit_name *name = commit->object.util;
 260         if (commit->object.parsed)
 261                 pretty_print_commit(CMIT_FMT_ONELINE, commit->buffer, ~0,
 262                                     pretty, sizeof(pretty));
 263         else
 264                 strcpy(pretty, "(unavailable)");
 265         if (!strncmp(pretty, "[PATCH] ", 8))
 266                 cp = pretty + 8;
 267         else
 268                 cp = pretty;
 269
 270         if (!no_name) {
 271                 if (name && name->head_name) {
 272                         printf("[%s", name->head_name);
 273                         if (name->generation) {
 274                                 if (name->generation == 1)
 275                                         printf("^");
 276                                 else
 277                                         printf("~%d", name->generation);
 278                         }
 279                         printf("] ");
 280                 }
 281                 else
 282                         printf("[%s] ",
 283                                find_unique_abbrev(commit->object.sha1, 7));
 284         }
 285         puts(cp);
 286 }
 287
 288 static char *ref_name[MAX_REVS + 1];
 289 static int ref_name_cnt;
 290
 291 static const char *find_digit_prefix(const char *s, int *v)
 292 {
 293         const char *p;
 294         int ver;
 295         char ch;
 296
 297         for (p = s, ver = 0;
 298              '0' <= (ch = *p) && ch <= '9';
 299              p++)
 300                 ver = ver * 10 + ch - '0';
 301         *v = ver;
 302         return p;
 303 }
 304
 305
 306 static int version_cmp(const char *a, const char *b)
 307 {
 308         while (1) {
 309                 int va, vb;
 310
 311                 a = find_digit_prefix(a, &va);
 312                 b = find_digit_prefix(b, &vb);
 313                 if (va != vb)
 314                         return va - vb;
 315
 316                 while (1) {
 317                         int ca = *a;
 318                         int cb = *b;
 319                         if ('0' <= ca && ca <= '9')
 320                                 ca = 0;
 321                         if ('0' <= cb && cb <= '9')
 322                                 cb = 0;
 323                         if (ca != cb)
 324                                 return ca - cb;
 325                         if (!ca)
 326                                 break;
 327                         a++;
 328                         b++;
 329                 }
 330                 if (!*a && !*b)
 331                         return 0;
 332         }
 333 }
 334
 335 static int compare_ref_name(const void *a_, const void *b_)
 336 {
 337         const char * const*a = a_, * const*b = b_;
 338         return version_cmp(*a, *b);
 339 }
 340
 341 static void sort_ref_range(int bottom, int top)
 342 {
 343         qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
 344               compare_ref_name);
 345 }
 346
 347 static int append_ref(const char *refname, const unsigned char *sha1)
 348 {
 349         struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 350         int i;
 351
 352         if (!commit)
 353                 return 0;
 354         /* Avoid adding the same thing twice */
 355         for (i = 0; i < ref_name_cnt; i++)
 356                 if (!strcmp(refname, ref_name[i]))
 357                         return 0;
 358
 359         if (MAX_REVS <= ref_name_cnt) {
 360                 fprintf(stderr, "warning: ignoring %s; "
 361                         "cannot handle more than %d refs\n",
 362                         refname, MAX_REVS);
 363                 return 0;
 364         }
 365         ref_name[ref_name_cnt++] = strdup(refname);
 366         ref_name[ref_name_cnt] = NULL;
 367         return 0;
 368 }
 369
 370 static int append_head_ref(const char *refname, const unsigned char *sha1)
 371 {
 372         unsigned char tmp[20];
 373         int ofs = 11;
 374         if (strncmp(refname, "refs/heads/", ofs))
 375                 return 0;
 376         /* If both heads/foo and tags/foo exists, get_sha1 would
 377          * get confused.
 378          */
 379         if (get_sha1(refname + ofs, tmp) || memcmp(tmp, sha1, 20))
 380                 ofs = 5;
 381         return append_ref(refname + ofs, sha1);
 382 }
 383
 384 static int append_tag_ref(const char *refname, const unsigned char *sha1)
 385 {
 386         if (strncmp(refname, "refs/tags/", 10))
 387                 return 0;
 388         return append_ref(refname + 5, sha1);
 389 }
 390
 391 static const char *match_ref_pattern = NULL;
 392 static int match_ref_slash = 0;
 393 static int count_slash(const char *s)
 394 {
 395         int cnt = 0;
 396         while (*s)
 397                 if (*s++ == '/')
 398                         cnt++;
 399         return cnt;
 400 }
 401
 402 static int append_matching_ref(const char *refname, const unsigned char *sha1)
 403 {
 404         /* we want to allow pattern hold/<asterisk> to show all
 405          * branches under refs/heads/hold/, and v0.99.9? to show
 406          * refs/tags/v0.99.9a and friends.
 407          */
 408         const char *tail;
 409         int slash = count_slash(refname);
 410         for (tail = refname; *tail && match_ref_slash < slash; )
 411                 if (*tail++ == '/')
 412                         slash--;
 413         if (!*tail)
 414                 return 0;
 415         if (fnmatch(match_ref_pattern, tail, 0))
 416                 return 0;
 417         if (!strncmp("refs/heads/", refname, 11))
 418                 return append_head_ref(refname, sha1);
 419         if (!strncmp("refs/tags/", refname, 10))
 420                 return append_tag_ref(refname, sha1);
 421         return append_ref(refname, sha1);
 422 }
 423
 424 static void snarf_refs(int head, int tag)
 425 {
 426         if (head) {
 427                 int orig_cnt = ref_name_cnt;
 428                 for_each_ref(append_head_ref);
 429                 sort_ref_range(orig_cnt, ref_name_cnt);
 430         }
 431         if (tag) {
 432                 int orig_cnt = ref_name_cnt;
 433                 for_each_ref(append_tag_ref);
 434                 sort_ref_range(orig_cnt, ref_name_cnt);
 435         }
 436 }
 437
 438 static int rev_is_head(char *head_path, int headlen,
 439                        char *name,
 440                        unsigned char *head_sha1, unsigned char *sha1)
 441 {
 442         int namelen;
 443         if ((!head_path[0]) || memcmp(head_sha1, sha1, 20))
 444                 return 0;
 445         namelen = strlen(name);
 446         if ((headlen < namelen) ||
 447             memcmp(head_path + headlen - namelen, name, namelen))
 448                 return 0;
 449         if (headlen == namelen ||
 450             head_path[headlen - namelen - 1] == '/')
 451                 return 1;
 452         return 0;
 453 }
 454
 455 static int show_merge_base(struct commit_list *seen, int num_rev)
 456 {
 457         int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 458         int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 459         int exit_status = 1;
 460
 461         while (seen) {
 462                 struct commit *commit = pop_one_commit(&seen);
 463                 int flags = commit->object.flags & all_mask;
 464                 if (!(flags & UNINTERESTING) &&
 465                     ((flags & all_revs) == all_revs)) {
 466                         puts(sha1_to_hex(commit->object.sha1));
 467                         exit_status = 0;
 468                         commit->object.flags |= UNINTERESTING;
 469                 }
 470         }
 471         return exit_status;
 472 }
 473
 474 static int show_independent(struct commit **rev,
 475                             int num_rev,
 476                             char **ref_name,
 477                             unsigned int *rev_mask)
 478 {
 479         int i;
 480
 481         for (i = 0; i < num_rev; i++) {
 482                 struct commit *commit = rev[i];
 483                 unsigned int flag = rev_mask[i];
 484
 485                 if (commit->object.flags == flag)
 486                         puts(sha1_to_hex(commit->object.sha1));
 487                 commit->object.flags |= UNINTERESTING;
 488         }
 489         return 0;
 490 }
 491
 492 static void append_one_rev(const char *av)
 493 {
 494         unsigned char revkey[20];
 495         if (!get_sha1(av, revkey)) {
 496                 append_ref(av, revkey);
 497                 return;
 498         }
 499         if (strchr(av, '*') || strchr(av, '?') || strchr(av, '[')) {
 500                 /* glob style match */
 501                 int saved_matches = ref_name_cnt;
 502                 match_ref_pattern = av;
 503                 match_ref_slash = count_slash(av);
 504                 for_each_ref(append_matching_ref);
 505                 if (saved_matches == ref_name_cnt &&
 506                     ref_name_cnt < MAX_REVS)
 507                         error("no matching refs with %s", av);
 508                 if (saved_matches + 1 < ref_name_cnt)
 509                         sort_ref_range(saved_matches, ref_name_cnt);
 510                 return;
 511         }
 512         die("bad sha1 reference %s", av);
 513 }
 514
 515 static int git_show_branch_config(const char *var, const char *value)
 516 {
 517         if (!strcmp(var, "showbranch.default")) {
 518                 if (default_alloc <= default_num + 1) {
 519                         default_alloc = default_alloc * 3 / 2 + 20;
 520                         default_arg = xrealloc(default_arg, sizeof *default_arg * default_alloc);
 521                 }
 522                 default_arg[default_num++] = strdup(value);
 523                 default_arg[default_num] = NULL;
 524                 return 0;
 525         }
 526
 527         return git_default_config(var, value);
 528 }
 529
 530 int main(int ac, char **av)
 531 {
 532         struct commit *rev[MAX_REVS], *commit;
 533         struct commit_list *list = NULL, *seen = NULL;
 534         unsigned int rev_mask[MAX_REVS];
 535         int num_rev, i, extra = 0;
 536         int all_heads = 0, all_tags = 0;
 537         int all_mask, all_revs;
 538         char head_path[128];
 539         const char *head_path_p;
 540         int head_path_len;
 541         unsigned char head_sha1[20];
 542         int merge_base = 0;
 543         int independent = 0;
 544         int no_name = 0;
 545         int sha1_name = 0;
 546         int shown_merge_point = 0;
 547         int topo_order = 0;
 548         int head_at = -1;
 549
 550         git_config(git_show_branch_config);
 551         setup_git_directory();
 552
 553         /* If nothing is specified, try the default first */
 554         if (ac == 1 && default_num) {
 555                 ac = default_num + 1;
 556                 av = default_arg - 1; /* ick; we would not address av[0] */
 557         }
 558
 559         while (1 < ac && av[1][0] == '-') {
 560                 char *arg = av[1];
 561                 if (!strcmp(arg, "--")) {
 562                         ac--; av++;
 563                         break;
 564                 }
 565                 else if (!strcmp(arg, "--all"))
 566                         all_heads = all_tags = 1;
 567                 else if (!strcmp(arg, "--heads"))
 568                         all_heads = 1;
 569                 else if (!strcmp(arg, "--tags"))
 570                         all_tags = 1;
 571                 else if (!strcmp(arg, "--more"))
 572                         extra = 1;
 573                 else if (!strcmp(arg, "--list"))
 574                         extra = -1;
 575                 else if (!strcmp(arg, "--no-name"))
 576                         no_name = 1;
 577                 else if (!strcmp(arg, "--sha1-name"))
 578                         sha1_name = 1;
 579                 else if (!strncmp(arg, "--more=", 7))
 580                         extra = atoi(arg + 7);
 581                 else if (!strcmp(arg, "--merge-base"))
 582                         merge_base = 1;
 583                 else if (!strcmp(arg, "--independent"))
 584                         independent = 1;
 585                 else if (!strcmp(arg, "--topo-order"))
 586                         topo_order = 1;
 587                 else
 588                         usage(show_branch_usage);
 589                 ac--; av++;
 590         }
 591         ac--; av++;
 592
 593         /* Only one of these is allowed */
 594         if (1 < independent + merge_base + (extra != 0))
 595                 usage(show_branch_usage);
 596
 597         /* If nothing is specified, show all branches by default */
 598         if (ac + all_heads + all_tags == 0)
 599                 all_heads = 1;
 600
 601         if (all_heads + all_tags)
 602                 snarf_refs(all_heads, all_tags);
 603         while (0 < ac) {
 604                 append_one_rev(*av);
 605                 ac--; av++;
 606         }
 607
 608         if (!ref_name_cnt) {
 609                 fprintf(stderr, "No revs to be shown.\n");
 610                 exit(0);
 611         }
 612
 613         for (num_rev = 0; ref_name[num_rev]; num_rev++) {
 614                 unsigned char revkey[20];
 615                 unsigned int flag = 1u << (num_rev + REV_SHIFT);
 616
 617                 if (MAX_REVS <= num_rev)
 618                         die("cannot handle more than %d revs.", MAX_REVS);
 619                 if (get_sha1(ref_name[num_rev], revkey))
 620                         die("'%s' is not a valid ref.", ref_name[num_rev]);
 621                 commit = lookup_commit_reference(revkey);
 622                 if (!commit)
 623                         die("cannot find commit %s (%s)",
 624                             ref_name[num_rev], revkey);
 625                 parse_commit(commit);
 626                 mark_seen(commit, &seen);
 627
 628                 /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
 629                  * and so on.  REV_SHIFT bits from bit 0 are used for
 630                  * internal bookkeeping.
 631                  */
 632                 commit->object.flags |= flag;
 633                 if (commit->object.flags == flag)
 634                         insert_by_date(commit, &list);
 635                 rev[num_rev] = commit;
 636         }
 637         for (i = 0; i < num_rev; i++)
 638                 rev_mask[i] = rev[i]->object.flags;
 639
 640         if (0 <= extra)
 641                 join_revs(&list, &seen, num_rev, extra);
 642
 643         head_path_p = resolve_ref(git_path("HEAD"), head_sha1, 1);
 644         if (head_path_p) {
 645                 head_path_len = strlen(head_path_p);
 646                 memcpy(head_path, head_path_p, head_path_len + 1);
 647         }
 648         else {
 649                 head_path_len = 0;
 650                 head_path[0] = 0;
 651         }
 652
 653         if (merge_base)
 654                 return show_merge_base(seen, num_rev);
 655
 656         if (independent)
 657                 return show_independent(rev, num_rev, ref_name, rev_mask);
 658
 659         /* Show list; --more=-1 means list-only */
 660         if (1 < num_rev || extra < 0) {
 661                 for (i = 0; i < num_rev; i++) {
 662                         int j;
 663                         int is_head = rev_is_head(head_path,
 664                                                   head_path_len,
 665                                                   ref_name[i],
 666                                                   head_sha1,
 667                                                   rev[i]->object.sha1);
 668                         if (extra < 0)
 669                                 printf("%c [%s] ",
 670                                        is_head ? '*' : ' ', ref_name[i]);
 671                         else {
 672                                 for (j = 0; j < i; j++)
 673                                         putchar(' ');
 674                                 printf("%c [%s] ",
 675                                        is_head ? '*' : '!', ref_name[i]);
 676                         }
 677                         /* header lines never need name */
 678                         show_one_commit(rev[i], 1);
 679                         if (is_head)
 680                                 head_at = i;
 681                 }
 682                 if (0 <= extra) {
 683                         for (i = 0; i < num_rev; i++)
 684                                 putchar('-');
 685                         putchar('\n');
 686                 }
 687         }
 688         if (extra < 0)
 689                 exit(0);
 690
 691         /* Sort topologically */
 692         if (topo_order)
 693                 sort_in_topological_order(&seen);
 694
 695         /* Give names to commits */
 696         if (!sha1_name && !no_name)
 697                 name_commits(seen, rev, ref_name, num_rev);
 698
 699         all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 700         all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 701
 702         while (seen) {
 703                 struct commit *commit = pop_one_commit(&seen);
 704                 int this_flag = commit->object.flags;
 705
 706                 shown_merge_point |= ((this_flag & all_revs) == all_revs);
 707
 708                 if (1 < num_rev) {
 709                         int is_merge = !!(commit->parents && commit->parents->next);
 710                         for (i = 0; i < num_rev; i++) {
 711                                 int mark;
 712                                 if (!(this_flag & (1u << (i + REV_SHIFT))))
 713                                         mark = ' ';
 714                                 else if (is_merge)
 715                                         mark = '-';
 716                                 else if (i == head_at)
 717                                         mark = '*';
 718                                 else
 719                                         mark = '+';
 720                                 putchar(mark);
 721                         }
 722                         putchar(' ');
 723                 }
 724                 show_one_commit(commit, no_name);
 725
 726                 if (shown_merge_point && --extra < 0)
 727                         break;
 728         }
 729         return 0;
 730 }