Andrew's git - gitweb.git/blob

   1#include <stdlib.h>
   2#include "cache.h"
   3#include "commit.h"
   4#include "refs.h"
   5
   6static const char show_branch_usage[] =
   7"git-show-branch [--all] [--heads] [--tags] [--more=count | --list | --independent | --merge-base ] [<refs>...]";
   8
   9#define UNINTERESTING   01
  10
  11#define REV_SHIFT        2
  12#define MAX_REVS        29 /* should not exceed bits_per_int - REV_SHIFT */
  13
  14static struct commit *interesting(struct commit_list *list)
  15{
  16        while (list) {
  17                struct commit *commit = list->item;
  18                list = list->next;
  19                if (commit->object.flags & UNINTERESTING)
  20                        continue;
  21                return commit;
  22        }
  23        return NULL;
  24}
  25
  26static struct commit *pop_one_commit(struct commit_list **list_p)
  27{
  28        struct commit *commit;
  29        struct commit_list *list;
  30        list = *list_p;
  31        commit = list->item;
  32        *list_p = list->next;
  33        free(list);
  34        return commit;
  35}
  36
  37struct commit_name {
  38        const char *head_name; /* which head's ancestor? */
  39        int generation; /* how many parents away from head_name */
  40};
  41
  42/* Name the commit as nth generation ancestor of head_name;
  43 * we count only the first-parent relationship for naming purposes.
  44 */
  45static void name_commit(struct commit *commit, const char *head_name, int nth)
  46{
  47        struct commit_name *name;
  48        if (!commit->object.util)
  49                commit->object.util = xmalloc(sizeof(struct commit_name));
  50        name = commit->object.util;
  51        name->head_name = head_name;
  52        name->generation = nth;
  53}
  54
  55/* Parent is the first parent of the commit.  We may name it
  56 * as (n+1)th generation ancestor of the same head_name as
  57 * commit is nth generation ancestore of, if that generation
  58 * number is better than the name it already has.
  59 */
  60static void name_parent(struct commit *commit, struct commit *parent)
  61{
  62        struct commit_name *commit_name = commit->object.util;
  63        struct commit_name *parent_name = parent->object.util;
  64        if (!commit_name)
  65                return;
  66        if (!parent_name ||
  67            commit_name->generation + 1 < parent_name->generation)
  68                name_commit(parent, commit_name->head_name,
  69                            commit_name->generation + 1);
  70}
  71
  72static int name_first_parent_chain(struct commit *c)
  73{
  74        int i = 0;
  75        while (c) {
  76                struct commit *p;
  77                if (!c->object.util)
  78                        break;
  79                if (!c->parents)
  80                        break;
  81                p = c->parents->item;
  82                if (!p->object.util) {
  83                        name_parent(c, p);
  84                        i++;
  85                }
  86                c = p;
  87        }
  88        return i;
  89}
  90
  91static void name_commits(struct commit_list *list,
  92                         struct commit **rev,
  93                         char **ref_name,
  94                         int num_rev)
  95{
  96        struct commit_list *cl;
  97        struct commit *c;
  98        int i;
  99
 100        /* First give names to the given heads */
 101        for (cl = list; cl; cl = cl->next) {
 102                c = cl->item;
 103                if (c->object.util)
 104                        continue;
 105                for (i = 0; i < num_rev; i++) {
 106                        if (rev[i] == c) {
 107                                name_commit(c, ref_name[i], 0);
 108                                break;
 109                        }
 110                }
 111        }
 112
 113        /* Then commits on the first parent ancestry chain */
 114        do {
 115                i = 0;
 116                for (cl = list; cl; cl = cl->next) {
 117                        i += name_first_parent_chain(cl->item);
 118                }
 119        } while (i);
 120
 121        /* Finally, any unnamed commits */
 122        do {
 123                i = 0;
 124                for (cl = list; cl; cl = cl->next) {
 125                        struct commit_list *parents;
 126                        struct commit_name *n;
 127                        int nth;
 128                        c = cl->item;
 129                        if (!c->object.util)
 130                                continue;
 131                        n = c->object.util;
 132                        parents = c->parents;
 133                        nth = 0;
 134                        while (parents) {
 135                                struct commit *p = parents->item;
 136                                char newname[1000];
 137                                parents = parents->next;
 138                                nth++;
 139                                if (p->object.util)
 140                                        continue;
 141                                switch (n->generation) {
 142                                case 0:
 143                                        sprintf(newname, "%s^%d",
 144                                                n->head_name, nth);
 145                                        break;
 146                                case 1:
 147                                        sprintf(newname, "%s^^%d",
 148                                                n->head_name, nth);
 149                                        break;
 150                                default:
 151                                        sprintf(newname, "%s~%d^%d",
 152                                                n->head_name, n->generation,
 153                                                nth);
 154                                }
 155                                name_commit(p, strdup(newname), 0);
 156                                i++;
 157                                name_first_parent_chain(p);
 158                        }
 159                }
 160        } while (i);
 161}
 162
 163static int mark_seen(struct commit *commit, struct commit_list **seen_p)
 164{
 165        if (!commit->object.flags) {
 166                insert_by_date(commit, seen_p);
 167                return 1;
 168        }
 169        return 0;
 170}
 171
 172static void join_revs(struct commit_list **list_p,
 173                      struct commit_list **seen_p,
 174                      int num_rev, int extra)
 175{
 176        int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 177        int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 178
 179        while (*list_p) {
 180                struct commit_list *parents;
 181                struct commit *commit = pop_one_commit(list_p);
 182                int flags = commit->object.flags & all_mask;
 183                int still_interesting = !!interesting(*list_p);
 184
 185                if (!still_interesting && extra < 0)
 186                        break;
 187
 188                mark_seen(commit, seen_p);
 189                if ((flags & all_revs) == all_revs)
 190                        flags |= UNINTERESTING;
 191                parents = commit->parents;
 192
 193                while (parents) {
 194                        struct commit *p = parents->item;
 195                        int this_flag = p->object.flags;
 196                        parents = parents->next;
 197                        if ((this_flag & flags) == flags)
 198                                continue;
 199                        parse_commit(p);
 200                        if (mark_seen(p, seen_p) && !still_interesting)
 201                                extra--;
 202                        p->object.flags |= flags;
 203                        insert_by_date(p, list_p);
 204                }
 205        }
 206}
 207
 208static void show_one_commit(struct commit *commit)
 209{
 210        char pretty[128], *cp;
 211        struct commit_name *name = commit->object.util;
 212        if (commit->object.parsed)
 213                pretty_print_commit(CMIT_FMT_ONELINE, commit->buffer, ~0,
 214                                    pretty, sizeof(pretty));
 215        else
 216                strcpy(pretty, "(unavailable)");
 217        if (!strncmp(pretty, "[PATCH] ", 8))
 218                cp = pretty + 8;
 219        else
 220                cp = pretty;
 221        if (name && name->head_name) {
 222                printf("[%s", name->head_name);
 223                if (name->generation)
 224                        printf("~%d", name->generation);
 225                printf("] ");
 226        }
 227        puts(cp);
 228}
 229
 230static char *ref_name[MAX_REVS + 1];
 231static int ref_name_cnt;
 232
 233static int compare_ref_name(const void *a_, const void *b_)
 234{
 235        const char * const*a = a_, * const*b = b_;
 236        return strcmp(*a, *b);
 237}
 238
 239static void sort_ref_range(int bottom, int top)
 240{
 241        qsort(ref_name + bottom, top - bottom, sizeof(ref_name[0]),
 242              compare_ref_name);
 243}
 244
 245static int append_ref(const char *refname, const unsigned char *sha1)
 246{
 247        struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 248        if (!commit)
 249                return 0;
 250        if (MAX_REVS <= ref_name_cnt) {
 251                fprintf(stderr, "warning: ignoring %s; "
 252                        "cannot handle more than %d refs",
 253                        refname, MAX_REVS);
 254                return 0;
 255        }
 256        ref_name[ref_name_cnt++] = strdup(refname);
 257        ref_name[ref_name_cnt] = NULL;
 258        return 0;
 259}
 260
 261static int append_head_ref(const char *refname, const unsigned char *sha1)
 262{
 263        if (strncmp(refname, "refs/heads/", 11))
 264                return 0;
 265        return append_ref(refname + 11, sha1);
 266}
 267
 268static int append_tag_ref(const char *refname, const unsigned char *sha1)
 269{
 270        if (strncmp(refname, "refs/tags/", 10))
 271                return 0;
 272        return append_ref(refname + 5, sha1);
 273}
 274
 275static void snarf_refs(int head, int tag)
 276{
 277        if (head) {
 278                int orig_cnt = ref_name_cnt;
 279                for_each_ref(append_head_ref);
 280                sort_ref_range(orig_cnt, ref_name_cnt);
 281        }
 282        if (tag) {
 283                int orig_cnt = ref_name_cnt;
 284                for_each_ref(append_tag_ref);
 285                sort_ref_range(orig_cnt, ref_name_cnt);
 286        }
 287}
 288
 289static int rev_is_head(char *head_path, int headlen,
 290                       char *name,
 291                       unsigned char *head_sha1, unsigned char *sha1)
 292{
 293        int namelen;
 294        if ((!head_path[0]) || memcmp(head_sha1, sha1, 20))
 295                return 0;
 296        namelen = strlen(name);
 297        if ((headlen < namelen) ||
 298            memcmp(head_path + headlen - namelen, name, namelen))
 299                return 0;
 300        if (headlen == namelen ||
 301            head_path[headlen - namelen - 1] == '/')
 302                return 1;
 303        return 0;
 304}
 305
 306static int show_merge_base(struct commit_list *seen, int num_rev)
 307{
 308        int all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 309        int all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 310        int exit_status = 1;
 311
 312        while (seen) {
 313                struct commit *commit = pop_one_commit(&seen);
 314                int flags = commit->object.flags & all_mask;
 315                if (!(flags & UNINTERESTING) &&
 316                    ((flags & all_revs) == all_revs)) {
 317                        puts(sha1_to_hex(commit->object.sha1));
 318                        exit_status = 0;
 319                        commit->object.flags |= UNINTERESTING;
 320                }
 321        }
 322        return exit_status;
 323}
 324
 325static int show_independent(struct commit **rev,
 326                            int num_rev,
 327                            char **ref_name,
 328                            unsigned int *rev_mask)
 329{
 330        int i;
 331
 332        for (i = 0; i < num_rev; i++) {
 333                struct commit *commit = rev[i];
 334                unsigned int flag = rev_mask[i];
 335
 336                if (commit->object.flags == flag)
 337                        puts(sha1_to_hex(commit->object.sha1));
 338                commit->object.flags |= UNINTERESTING;
 339        }
 340        return 0;
 341}
 342
 343int main(int ac, char **av)
 344{
 345        struct commit *rev[MAX_REVS], *commit;
 346        struct commit_list *list = NULL, *seen = NULL;
 347        unsigned int rev_mask[MAX_REVS];
 348        int num_rev, i, extra = 0;
 349        int all_heads = 0, all_tags = 0;
 350        int all_mask, all_revs, shown_merge_point;
 351        char head_path[128];
 352        const char *head_path_p;
 353        int head_path_len;
 354        unsigned char head_sha1[20];
 355        int merge_base = 0;
 356        int independent = 0;
 357        char **label;
 358
 359        setup_git_directory();
 360
 361        while (1 < ac && av[1][0] == '-') {
 362                char *arg = av[1];
 363                if (!strcmp(arg, "--all"))
 364                        all_heads = all_tags = 1;
 365                else if (!strcmp(arg, "--heads"))
 366                        all_heads = 1;
 367                else if (!strcmp(arg, "--tags"))
 368                        all_tags = 1;
 369                else if (!strcmp(arg, "--more"))
 370                        extra = 1;
 371                else if (!strcmp(arg, "--list"))
 372                        extra = -1;
 373                else if (!strncmp(arg, "--more=", 7))
 374                        extra = atoi(arg + 7);
 375                else if (!strcmp(arg, "--merge-base"))
 376                        merge_base = 1;
 377                else if (!strcmp(arg, "--independent"))
 378                        independent = 1;
 379                else
 380                        usage(show_branch_usage);
 381                ac--; av++;
 382        }
 383        ac--; av++;
 384
 385        /* Only one of these is allowed */
 386        if (1 < independent + merge_base + (extra != 0))
 387                usage(show_branch_usage);
 388
 389        if (all_heads + all_tags)
 390                snarf_refs(all_heads, all_tags);
 391
 392        while (0 < ac) {
 393                unsigned char revkey[20];
 394                if (get_sha1(*av, revkey))
 395                        die("bad sha1 reference %s", *av);
 396                append_ref(*av, revkey);
 397                ac--; av++;
 398        }
 399
 400        /* If still no revs, then add heads */
 401        if (!ref_name_cnt)
 402                snarf_refs(1, 0);
 403
 404        for (num_rev = 0; ref_name[num_rev]; num_rev++) {
 405                unsigned char revkey[20];
 406                unsigned int flag = 1u << (num_rev + REV_SHIFT);
 407
 408                if (MAX_REVS <= num_rev)
 409                        die("cannot handle more than %d revs.", MAX_REVS);
 410                if (get_sha1(ref_name[num_rev], revkey))
 411                        usage(show_branch_usage);
 412                commit = lookup_commit_reference(revkey);
 413                if (!commit)
 414                        die("cannot find commit %s (%s)",
 415                            ref_name[num_rev], revkey);
 416                parse_commit(commit);
 417                mark_seen(commit, &seen);
 418
 419                /* rev#0 uses bit REV_SHIFT, rev#1 uses bit REV_SHIFT+1,
 420                 * and so on.  REV_SHIFT bits from bit 0 are used for
 421                 * internal bookkeeping.
 422                 */
 423                commit->object.flags |= flag;
 424                if (commit->object.flags == flag)
 425                        insert_by_date(commit, &list);
 426                rev[num_rev] = commit;
 427        }
 428        for (i = 0; i < num_rev; i++)
 429                rev_mask[i] = rev[i]->object.flags;
 430
 431        if (0 <= extra)
 432                join_revs(&list, &seen, num_rev, extra);
 433
 434        head_path_p = resolve_ref(git_path("HEAD"), head_sha1, 1);
 435        if (head_path_p) {
 436                head_path_len = strlen(head_path_p);
 437                memcpy(head_path, head_path_p, head_path_len + 1);
 438        }
 439        else {
 440                head_path_len = 0;
 441                head_path[0] = 0;
 442        }
 443
 444        if (merge_base)
 445                return show_merge_base(seen, num_rev);
 446
 447        if (independent)
 448                return show_independent(rev, num_rev, ref_name, rev_mask);
 449
 450        /* Show list; --more=-1 means list-only */
 451        if (1 < num_rev || extra < 0) {
 452                for (i = 0; i < num_rev; i++) {
 453                        int j;
 454                        int is_head = rev_is_head(head_path,
 455                                                  head_path_len,
 456                                                  ref_name[i],
 457                                                  head_sha1,
 458                                                  rev[i]->object.sha1);
 459                        if (extra < 0)
 460                                printf("%c [%s] ",
 461                                       is_head ? '*' : ' ', ref_name[i]);
 462                        else {
 463                                for (j = 0; j < i; j++)
 464                                        putchar(' ');
 465                                printf("%c [%s] ",
 466                                       is_head ? '*' : '!', ref_name[i]);
 467                        }
 468                        show_one_commit(rev[i]);
 469                }
 470                if (0 <= extra) {
 471                        for (i = 0; i < num_rev; i++)
 472                                putchar('-');
 473                        putchar('\n');
 474                }
 475        }
 476        if (extra < 0)
 477                exit(0);
 478
 479        /* Sort topologically */
 480        sort_in_topological_order(&seen);
 481
 482        /* Give names to commits */
 483        name_commits(seen, rev, ref_name, num_rev);
 484
 485        all_mask = ((1u << (REV_SHIFT + num_rev)) - 1);
 486        all_revs = all_mask & ~((1u << REV_SHIFT) - 1);
 487        shown_merge_point = 0;
 488
 489        while (seen) {
 490                struct commit *commit = pop_one_commit(&seen);
 491                int this_flag = commit->object.flags;
 492                int is_merge_point = (this_flag & all_revs) == all_revs;
 493                static char *obvious[] = { "" };
 494
 495                if (is_merge_point)
 496                        shown_merge_point = 1;
 497
 498                if (1 < num_rev) {
 499                        for (i = 0; i < num_rev; i++)
 500                                putchar((this_flag & (1u << (i + REV_SHIFT)))
 501                                        ? '+' : ' ');
 502                        putchar(' ');
 503                }
 504                show_one_commit(commit);
 505                if (num_rev == 1)
 506                        label = obvious;
 507                if (shown_merge_point && is_merge_point)
 508                        if (--extra < 0)
 509                                break;
 510        }
 511        return 0;
 512}