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 int compare_ref_name(const void *a_, const void *b_)
 288 {
 289         const char * const*a = a_, * const*b = b_;
 290         return strcmp(*a, *b);
 291 }
 292
 293 static void sort_ref_range(int bottom, int top)
 294 {
 295         qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
 296               compare_ref_name);
 297 }
 298
 299 static int append_ref(const char *refname, const unsigned char *sha1)
 300 {
 301         struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 302         if (!commit)
 303                 return 0;
 304         if (MAX_REVS <= ref_name_cnt) {
 305                 fprintf(stderr, "warning: ignoring %s; "
 306                         "cannot handle more than %d refs\n",
 307                         refname, MAX_REVS);
 308                 return 0;
 309         }
 310         ref_name[ref_name_cnt++] = strdup(refname);
 311         ref_name[ref_name_cnt] = NULL;
 312         return 0;
 313 }
 314
 315 static int append_head_ref(const char *refname, const unsigned char *sha1)
 316 {
 317         unsigned char tmp[20];
 318         int ofs = 11;
 319         if (strncmp(refname, "refs/heads/", ofs))
 320                 return 0;
 321         /* If both heads/foo and tags/foo exists, get_sha1 would
 322          * get confused.
 323          */
 324         if (get_sha1(refname + ofs, tmp) || memcmp(tmp, sha1, 20))
 325                 ofs = 5;
 326         return append_ref(refname + ofs, sha1);
 327 }
 328
 329 static int append_tag_ref(const char *refname, const unsigned char *sha1)
 330 {
 331         if (strncmp(refname, "refs/tags/", 10))
 332                 return 0;
 333         return append_ref(refname + 5, sha1);
 334 }
 335
 336 static const char *match_ref_pattern = NULL;
 337 static int match_ref_slash = 0;
 338 static int count_slash(const char *s)
 339 {
 340         int cnt = 0;
 341         while (*s)
 342                 if (*s++ == '/')
 343                         cnt++;
 344         return cnt;
 345 }
 346
 347 static int append_matching_ref(const char *refname, const unsigned char *sha1)
 348 {
 349         /* we want to allow pattern hold/<asterisk> to show all
 350          * branches under refs/heads/hold/, and v0.99.9? to show
 351          * refs/tags/v0.99.9a and friends.
 352          */
 353         const char *tail;
 354         int slash = count_slash(refname);
 355         for (tail = refname; *tail && match_ref_slash < slash; )
 356                 if (*tail++ == '/')
 357                         slash--;
 358         if (!*tail)
 359                 return 0;
 360         if (fnmatch(match_ref_pattern, tail, 0))
 361                 return 0;
 362         if (!strncmp("refs/heads/", refname, 11))
 363                 return append_head_ref(refname, sha1);
 364         if (!strncmp("refs/tags/", refname, 10))
 365                 return append_tag_ref(refname, sha1);
 366         return append_ref(refname, sha1);
 367 }
 368
 369 static void snarf_refs(int head, int tag)
 370 {
 371         if (head) {
 372                 int orig_cnt = ref_name_cnt;
 373                 for_each_ref(append_head_ref);
 374                 sort_ref_range(orig_cnt, ref_name_cnt);
 375         }
 376         if (tag) {
 377                 int orig_cnt = ref_name_cnt;
 378                 for_each_ref(append_tag_ref);
 379                 sort_ref_range(orig_cnt, ref_name_cnt);
 380         }
 381 }
 382
 383 static int rev_is_head(char *head_path, int headlen,
 384                        char *name,
 385                        unsigned char *head_sha1, unsigned char *sha1)
 386 {
 387         int namelen;
 388         if ((!head_path[0]) || memcmp(head_sha1, sha1, 20))
 389                 return 0;
 390         namelen = strlen(name);
 391         if ((headlen < namelen) ||
 392             memcmp(head_path + headlen - namelen, name, namelen))
 393                 return 0;
 394         if (headlen == namelen ||
 395             head_path[headlen - namelen - 1] == '/')
 396                 return 1;
 397         return 0;
 398 }
 399
 400 static int show_merge_base(struct commit_list *seen, int num_rev)
 401 {
 402         int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 403         int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 404         int exit_status = 1;
 405
 406         while (seen) {
 407                 struct commit *commit = pop_one_commit(&seen);
 408                 int flags = commit->object.flags & all_mask;
 409                 if (!(flags & UNINTERESTING) &&
 410                     ((flags & all_revs) == all_revs)) {
 411                         puts(sha1_to_hex(commit->object.sha1));
 412                         exit_status = 0;
 413                         commit->object.flags |= UNINTERESTING;
 414                 }
 415         }
 416         return exit_status;
 417 }
 418
 419 static int show_independent(struct commit **rev,
 420                             int num_rev,
 421                             char **ref_name,
 422                             unsigned int *rev_mask)
 423 {
 424         int i;
 425
 426         for (i = 0; i < num_rev; i++) {
 427                 struct commit *commit = rev[i];
 428                 unsigned int flag = rev_mask[i];
 429
 430                 if (commit->object.flags == flag)
 431                         puts(sha1_to_hex(commit->object.sha1));
 432                 commit->object.flags |= UNINTERESTING;
 433         }
 434         return 0;
 435 }
 436
 437 static void append_one_rev(const char *av)
 438 {
 439         unsigned char revkey[20];
 440         if (!get_sha1(av, revkey)) {
 441                 append_ref(av, revkey);
 442                 return;
 443         }
 444         if (strchr(av, '*') || strchr(av, '?')) {
 445                 /* glob style match */
 446                 int saved_matches = ref_name_cnt;
 447                 match_ref_pattern = av;
 448                 match_ref_slash = count_slash(av);
 449                 for_each_ref(append_matching_ref);
 450                 if (saved_matches == ref_name_cnt &&
 451                     ref_name_cnt < MAX_REVS)
 452                         error("no matching refs with %s", av);
 453                 if (saved_matches + 1 < ref_name_cnt)
 454                         sort_ref_range(saved_matches, ref_name_cnt);
 455                 return;
 456         }
 457         die("bad sha1 reference %s", av);
 458 }
 459
 460 int main(int ac, char **av)
 461 {
 462         struct commit *rev[MAX_REVS], *commit;
 463         struct commit_list *list = NULL, *seen = NULL;
 464         unsigned int rev_mask[MAX_REVS];
 465         int num_rev, i, extra = 0;
 466         int all_heads = 0, all_tags = 0;
 467         int all_mask, all_revs;
 468         char head_path[128];
 469         const char *head_path_p;
 470         int head_path_len;
 471         unsigned char head_sha1[20];
 472         int merge_base = 0;
 473         int independent = 0;
 474         int no_name = 0;
 475         int sha1_name = 0;
 476         int shown_merge_point = 0;
 477         int topo_order = 0;
 478
 479         setup_git_directory();
 480
 481         while (1 < ac && av[1][0] == '-') {
 482                 char *arg = av[1];
 483                 if (!strcmp(arg, "--all"))
 484                         all_heads = all_tags = 1;
 485                 else if (!strcmp(arg, "--heads"))
 486                         all_heads = 1;
 487                 else if (!strcmp(arg, "--tags"))
 488                         all_tags = 1;
 489                 else if (!strcmp(arg, "--more"))
 490                         extra = 1;
 491                 else if (!strcmp(arg, "--list"))
 492                         extra = -1;
 493                 else if (!strcmp(arg, "--no-name"))
 494                         no_name = 1;
 495                 else if (!strcmp(arg, "--sha1-name"))
 496                         sha1_name = 1;
 497                 else if (!strncmp(arg, "--more=", 7))
 498                         extra = atoi(arg + 7);
 499                 else if (!strcmp(arg, "--merge-base"))
 500                         merge_base = 1;
 501                 else if (!strcmp(arg, "--independent"))
 502                         independent = 1;
 503                 else if (!strcmp(arg, "--topo-order"))
 504                         topo_order = 1;
 505                 else
 506                         usage(show_branch_usage);
 507                 ac--; av++;
 508         }
 509         ac--; av++;
 510
 511         /* Only one of these is allowed */
 512         if (1 < independent + merge_base + (extra != 0))
 513                 usage(show_branch_usage);
 514
 515         if (all_heads + all_tags)
 516                 snarf_refs(all_heads, all_tags);
 517
 518         if (ac) {
 519                 while (0 < ac) {
 520                         append_one_rev(*av);
 521                         ac--; av++;
 522                 }
 523         }
 524         else {
 525                 /* If no revs given, then add heads */
 526                 snarf_refs(1, 0);
 527         }
 528         if (!ref_name_cnt) {
 529                 fprintf(stderr, "No revs to be shown.\n");
 530                 exit(0);
 531         }
 532
 533         for (num_rev = 0; ref_name[num_rev]; num_rev++) {
 534                 unsigned char revkey[20];
 535                 unsigned int flag = 1u << (num_rev + REV_SHIFT);
 536
 537                 if (MAX_REVS <= num_rev)
 538                         die("cannot handle more than %d revs.", MAX_REVS);
 539                 if (get_sha1(ref_name[num_rev], revkey))
 540                         die("'%s' is not a valid ref.", ref_name[num_rev]);
 541                 commit = lookup_commit_reference(revkey);
 542                 if (!commit)
 543                         die("cannot find commit %s (%s)",
 544                             ref_name[num_rev], revkey);
 545                 parse_commit(commit);
 546                 mark_seen(commit, &seen);
 547
 548                 /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
 549                  * and so on.  REV_SHIFT bits from bit 0 are used for
 550                  * internal bookkeeping.
 551                  */
 552                 commit->object.flags |= flag;
 553                 if (commit->object.flags == flag)
 554                         insert_by_date(commit, &list);
 555                 rev[num_rev] = commit;
 556         }
 557         for (i = 0; i < num_rev; i++)
 558                 rev_mask[i] = rev[i]->object.flags;
 559
 560         if (0 <= extra)
 561                 join_revs(&list, &seen, num_rev, extra);
 562
 563         head_path_p = resolve_ref(git_path("HEAD"), head_sha1, 1);
 564         if (head_path_p) {
 565                 head_path_len = strlen(head_path_p);
 566                 memcpy(head_path, head_path_p, head_path_len + 1);
 567         }
 568         else {
 569                 head_path_len = 0;
 570                 head_path[0] = 0;
 571         }
 572
 573         if (merge_base)
 574                 return show_merge_base(seen, num_rev);
 575
 576         if (independent)
 577                 return show_independent(rev, num_rev, ref_name, rev_mask);
 578
 579         /* Show list; --more=-1 means list-only */
 580         if (1 < num_rev || extra < 0) {
 581                 for (i = 0; i < num_rev; i++) {
 582                         int j;
 583                         int is_head = rev_is_head(head_path,
 584                                                   head_path_len,
 585                                                   ref_name[i],
 586                                                   head_sha1,
 587                                                   rev[i]->object.sha1);
 588                         if (extra < 0)
 589                                 printf("%c [%s] ",
 590                                        is_head ? '*' : ' ', ref_name[i]);
 591                         else {
 592                                 for (j = 0; j < i; j++)
 593                                         putchar(' ');
 594                                 printf("%c [%s] ",
 595                                        is_head ? '*' : '!', ref_name[i]);
 596                         }
 597                         /* header lines never need name */
 598                         show_one_commit(rev[i], 1);
 599                 }
 600                 if (0 <= extra) {
 601                         for (i = 0; i < num_rev; i++)
 602                                 putchar('-');
 603                         putchar('\n');
 604                 }
 605         }
 606         if (extra < 0)
 607                 exit(0);
 608
 609         /* Sort topologically */
 610         if (topo_order)
 611                 sort_in_topological_order(&seen);
 612
 613         /* Give names to commits */
 614         if (!sha1_name && !no_name)
 615                 name_commits(seen, rev, ref_name, num_rev);
 616
 617         all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 618         all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 619
 620         while (seen) {
 621                 struct commit *commit = pop_one_commit(&seen);
 622                 int this_flag = commit->object.flags;
 623
 624                 shown_merge_point |= ((this_flag & all_revs) == all_revs);
 625
 626                 if (1 < num_rev) {
 627                         for (i = 0; i < num_rev; i++)
 628                                 putchar((this_flag & (1u << (i + REV_SHIFT)))
 629                                         ? '+' : ' ');
 630                         putchar(' ');
 631                 }
 632                 show_one_commit(commit, no_name);
 633
 634                 if (shown_merge_point && --extra < 0)
 635                         break;
 636         }
 637         return 0;
 638 }