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