Andrew's git / gitweb.git / show-branch.c
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show-branch.con commit \n usage in stderr output (7246ed4)
   1#include <stdlib.h>
   2#include <fnmatch.h>
   3#include "cache.h"
   4#include "commit.h"
   5#include "refs.h"
   6
   7static 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
  15static 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
  27static 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
  38struct 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 */
  46static 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 */
  61static 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
  73static 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
  92static 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
 167static 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
 176static 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
 252static 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
 284static char *ref_name[MAX_REVS + 1];
 285static int ref_name_cnt;
 286
 287static 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
 293static 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
 299static 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
 315static 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
 329static 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
 336static const char *match_ref_pattern = NULL;
 337static int match_ref_slash = 0;
 338static int count_slash(const char *s)
 339{
 340        int cnt = 0;
 341        while (*s)
 342                if (*s++ == '/')
 343                        cnt++;
 344        return cnt;
 345}
 346
 347static 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
 369static 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
 383static 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
 400static 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
 419static 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
 437static 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
 460int 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}