builtin/submodule--helper.c

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "parse-options.h"
   4 #include "quote.h"
   5 #include "pathspec.h"
   6 #include "dir.h"
   7 #include "utf8.h"
   8 #include "submodule.h"
   9 #include "submodule-config.h"
  10 #include "string-list.h"
  11 #include "run-command.h"
  12 #include "remote.h"
  13 #include "refs.h"
  14 #include "connect.h"
  15
  16 static char *get_default_remote(void)
  17 {
  18         char *dest = NULL, *ret;
  19         unsigned char sha1[20];
  20         struct strbuf sb = STRBUF_INIT;
  21         const char *refname = resolve_ref_unsafe("HEAD", 0, sha1, NULL);
  22
  23         if (!refname)
  24                 die(_("No such ref: %s"), "HEAD");
  25
  26         /* detached HEAD */
  27         if (!strcmp(refname, "HEAD"))
  28                 return xstrdup("origin");
  29
  30         if (!skip_prefix(refname, "refs/heads/", &refname))
  31                 die(_("Expecting a full ref name, got %s"), refname);
  32
  33         strbuf_addf(&sb, "branch.%s.remote", refname);
  34         if (git_config_get_string(sb.buf, &dest))
  35                 ret = xstrdup("origin");
  36         else
  37                 ret = dest;
  38
  39         strbuf_release(&sb);
  40         return ret;
  41 }
  42
  43 static int starts_with_dot_slash(const char *str)
  44 {
  45         return str[0] == '.' && is_dir_sep(str[1]);
  46 }
  47
  48 static int starts_with_dot_dot_slash(const char *str)
  49 {
  50         return str[0] == '.' && str[1] == '.' && is_dir_sep(str[2]);
  51 }
  52
  53 /*
  54  * Returns 1 if it was the last chop before ':'.
  55  */
  56 static int chop_last_dir(char **remoteurl, int is_relative)
  57 {
  58         char *rfind = find_last_dir_sep(*remoteurl);
  59         if (rfind) {
  60                 *rfind = '\0';
  61                 return 0;
  62         }
  63
  64         rfind = strrchr(*remoteurl, ':');
  65         if (rfind) {
  66                 *rfind = '\0';
  67                 return 1;
  68         }
  69
  70         if (is_relative || !strcmp(".", *remoteurl))
  71                 die(_("cannot strip one component off url '%s'"),
  72                         *remoteurl);
  73
  74         free(*remoteurl);
  75         *remoteurl = xstrdup(".");
  76         return 0;
  77 }
  78
  79 /*
  80  * The `url` argument is the URL that navigates to the submodule origin
  81  * repo. When relative, this URL is relative to the superproject origin
  82  * URL repo. The `up_path` argument, if specified, is the relative
  83  * path that navigates from the submodule working tree to the superproject
  84  * working tree. Returns the origin URL of the submodule.
  85  *
  86  * Return either an absolute URL or filesystem path (if the superproject
  87  * origin URL is an absolute URL or filesystem path, respectively) or a
  88  * relative file system path (if the superproject origin URL is a relative
  89  * file system path).
  90  *
  91  * When the output is a relative file system path, the path is either
  92  * relative to the submodule working tree, if up_path is specified, or to
  93  * the superproject working tree otherwise.
  94  *
  95  * NEEDSWORK: This works incorrectly on the domain and protocol part.
  96  * remote_url      url              outcome          expectation
  97  * http://a.com/b  ../c             http://a.com/c   as is
  98  * http://a.com/b  ../../c          http://c         error out
  99  * http://a.com/b  ../../../c       http:/c          error out
 100  * http://a.com/b  ../../../../c    http:c           error out
 101  * http://a.com/b  ../../../../../c    .:c           error out
 102  * NEEDSWORK: Given how chop_last_dir() works, this function is broken
 103  * when a local part has a colon in its path component, too.
 104  */
 105 static char *relative_url(const char *remote_url,
 106                                 const char *url,
 107                                 const char *up_path)
 108 {
 109         int is_relative = 0;
 110         int colonsep = 0;
 111         char *out;
 112         char *remoteurl = xstrdup(remote_url);
 113         struct strbuf sb = STRBUF_INIT;
 114         size_t len = strlen(remoteurl);
 115
 116         if (is_dir_sep(remoteurl[len]))
 117                 remoteurl[len] = '\0';
 118
 119         if (!url_is_local_not_ssh(remoteurl) || is_absolute_path(remoteurl))
 120                 is_relative = 0;
 121         else {
 122                 is_relative = 1;
 123                 /*
 124                  * Prepend a './' to ensure all relative
 125                  * remoteurls start with './' or '../'
 126                  */
 127                 if (!starts_with_dot_slash(remoteurl) &&
 128                     !starts_with_dot_dot_slash(remoteurl)) {
 129                         strbuf_reset(&sb);
 130                         strbuf_addf(&sb, "./%s", remoteurl);
 131                         free(remoteurl);
 132                         remoteurl = strbuf_detach(&sb, NULL);
 133                 }
 134         }
 135         /*
 136          * When the url starts with '../', remove that and the
 137          * last directory in remoteurl.
 138          */
 139         while (url) {
 140                 if (starts_with_dot_dot_slash(url)) {
 141                         url += 3;
 142                         colonsep |= chop_last_dir(&remoteurl, is_relative);
 143                 } else if (starts_with_dot_slash(url))
 144                         url += 2;
 145                 else
 146                         break;
 147         }
 148         strbuf_reset(&sb);
 149         strbuf_addf(&sb, "%s%s%s", remoteurl, colonsep ? ":" : "/", url);
 150         free(remoteurl);
 151
 152         if (starts_with_dot_slash(sb.buf))
 153                 out = xstrdup(sb.buf + 2);
 154         else
 155                 out = xstrdup(sb.buf);
 156         strbuf_reset(&sb);
 157
 158         if (!up_path || !is_relative)
 159                 return out;
 160
 161         strbuf_addf(&sb, "%s%s", up_path, out);
 162         free(out);
 163         return strbuf_detach(&sb, NULL);
 164 }
 165
 166 static int resolve_relative_url(int argc, const char **argv, const char *prefix)
 167 {
 168         char *remoteurl = NULL;
 169         char *remote = get_default_remote();
 170         const char *up_path = NULL;
 171         char *res;
 172         const char *url;
 173         struct strbuf sb = STRBUF_INIT;
 174
 175         if (argc != 2 && argc != 3)
 176                 die("resolve-relative-url only accepts one or two arguments");
 177
 178         url = argv[1];
 179         strbuf_addf(&sb, "remote.%s.url", remote);
 180         free(remote);
 181
 182         if (git_config_get_string(sb.buf, &remoteurl))
 183                 /* the repository is its own authoritative upstream */
 184                 remoteurl = xgetcwd();
 185
 186         if (argc == 3)
 187                 up_path = argv[2];
 188
 189         res = relative_url(remoteurl, url, up_path);
 190         puts(res);
 191         free(res);
 192         free(remoteurl);
 193         return 0;
 194 }
 195
 196 static int resolve_relative_url_test(int argc, const char **argv, const char *prefix)
 197 {
 198         char *remoteurl, *res;
 199         const char *up_path, *url;
 200
 201         if (argc != 4)
 202                 die("resolve-relative-url-test only accepts three arguments: <up_path> <remoteurl> <url>");
 203
 204         up_path = argv[1];
 205         remoteurl = xstrdup(argv[2]);
 206         url = argv[3];
 207
 208         if (!strcmp(up_path, "(null)"))
 209                 up_path = NULL;
 210
 211         res = relative_url(remoteurl, url, up_path);
 212         puts(res);
 213         free(res);
 214         free(remoteurl);
 215         return 0;
 216 }
 217
 218 struct module_list {
 219         const struct cache_entry **entries;
 220         int alloc, nr;
 221 };
 222 #define MODULE_LIST_INIT { NULL, 0, 0 }
 223
 224 static int module_list_compute(int argc, const char **argv,
 225                                const char *prefix,
 226                                struct pathspec *pathspec,
 227                                struct module_list *list)
 228 {
 229         int i, result = 0;
 230         char *ps_matched = NULL;
 231         parse_pathspec(pathspec, 0,
 232                        PATHSPEC_PREFER_FULL |
 233                        PATHSPEC_STRIP_SUBMODULE_SLASH_CHEAP,
 234                        prefix, argv);
 235
 236         if (pathspec->nr)
 237                 ps_matched = xcalloc(pathspec->nr, 1);
 238
 239         if (read_cache() < 0)
 240                 die(_("index file corrupt"));
 241
 242         for (i = 0; i < active_nr; i++) {
 243                 const struct cache_entry *ce = active_cache[i];
 244
 245                 if (!match_pathspec(pathspec, ce->name, ce_namelen(ce),
 246                                     0, ps_matched, 1) ||
 247                     !S_ISGITLINK(ce->ce_mode))
 248                         continue;
 249
 250                 ALLOC_GROW(list->entries, list->nr + 1, list->alloc);
 251                 list->entries[list->nr++] = ce;
 252                 while (i + 1 < active_nr &&
 253                        !strcmp(ce->name, active_cache[i + 1]->name))
 254                         /*
 255                          * Skip entries with the same name in different stages
 256                          * to make sure an entry is returned only once.
 257                          */
 258                         i++;
 259         }
 260
 261         if (ps_matched && report_path_error(ps_matched, pathspec, prefix))
 262                 result = -1;
 263
 264         free(ps_matched);
 265
 266         return result;
 267 }
 268
 269 static int module_list(int argc, const char **argv, const char *prefix)
 270 {
 271         int i;
 272         struct pathspec pathspec;
 273         struct module_list list = MODULE_LIST_INIT;
 274
 275         struct option module_list_options[] = {
 276                 OPT_STRING(0, "prefix", &prefix,
 277                            N_("path"),
 278                            N_("alternative anchor for relative paths")),
 279                 OPT_END()
 280         };
 281
 282         const char *const git_submodule_helper_usage[] = {
 283                 N_("git submodule--helper list [--prefix=<path>] [<path>...]"),
 284                 NULL
 285         };
 286
 287         argc = parse_options(argc, argv, prefix, module_list_options,
 288                              git_submodule_helper_usage, 0);
 289
 290         if (module_list_compute(argc, argv, prefix, &pathspec, &list) < 0)
 291                 return 1;
 292
 293         for (i = 0; i < list.nr; i++) {
 294                 const struct cache_entry *ce = list.entries[i];
 295
 296                 if (ce_stage(ce))
 297                         printf("%06o %s U\t", ce->ce_mode, sha1_to_hex(null_sha1));
 298                 else
 299                         printf("%06o %s %d\t", ce->ce_mode, sha1_to_hex(ce->sha1), ce_stage(ce));
 300
 301                 utf8_fprintf(stdout, "%s\n", ce->name);
 302         }
 303         return 0;
 304 }
 305
 306 static void init_submodule(const char *path, const char *prefix, int quiet)
 307 {
 308         const struct submodule *sub;
 309         struct strbuf sb = STRBUF_INIT;
 310         char *upd = NULL, *url = NULL, *displaypath;
 311
 312         /* Only loads from .gitmodules, no overlay with .git/config */
 313         gitmodules_config();
 314
 315         if (prefix) {
 316                 strbuf_addf(&sb, "%s%s", prefix, path);
 317                 displaypath = strbuf_detach(&sb, NULL);
 318         } else
 319                 displaypath = xstrdup(path);
 320
 321         sub = submodule_from_path(null_sha1, path);
 322
 323         if (!sub)
 324                 die(_("No url found for submodule path '%s' in .gitmodules"),
 325                         displaypath);
 326
 327         /*
 328          * Copy url setting when it is not set yet.
 329          * To look up the url in .git/config, we must not fall back to
 330          * .gitmodules, so look it up directly.
 331          */
 332         strbuf_reset(&sb);
 333         strbuf_addf(&sb, "submodule.%s.url", sub->name);
 334         if (git_config_get_string(sb.buf, &url)) {
 335                 url = xstrdup(sub->url);
 336
 337                 if (!url)
 338                         die(_("No url found for submodule path '%s' in .gitmodules"),
 339                                 displaypath);
 340
 341                 /* Possibly a url relative to parent */
 342                 if (starts_with_dot_dot_slash(url) ||
 343                     starts_with_dot_slash(url)) {
 344                         char *remoteurl, *relurl;
 345                         char *remote = get_default_remote();
 346                         struct strbuf remotesb = STRBUF_INIT;
 347                         strbuf_addf(&remotesb, "remote.%s.url", remote);
 348                         free(remote);
 349
 350                         if (git_config_get_string(remotesb.buf, &remoteurl))
 351                                 /*
 352                                  * The repository is its own
 353                                  * authoritative upstream
 354                                  */
 355                                 remoteurl = xgetcwd();
 356                         relurl = relative_url(remoteurl, url, NULL);
 357                         strbuf_release(&remotesb);
 358                         free(remoteurl);
 359                         free(url);
 360                         url = relurl;
 361                 }
 362
 363                 if (git_config_set_gently(sb.buf, url))
 364                         die(_("Failed to register url for submodule path '%s'"),
 365                             displaypath);
 366                 if (!quiet)
 367                         fprintf(stderr,
 368                                 _("Submodule '%s' (%s) registered for path '%s'\n"),
 369                                 sub->name, url, displaypath);
 370         }
 371
 372         /* Copy "update" setting when it is not set yet */
 373         strbuf_reset(&sb);
 374         strbuf_addf(&sb, "submodule.%s.update", sub->name);
 375         if (git_config_get_string(sb.buf, &upd) &&
 376             sub->update_strategy.type != SM_UPDATE_UNSPECIFIED) {
 377                 if (sub->update_strategy.type == SM_UPDATE_COMMAND) {
 378                         fprintf(stderr, _("warning: command update mode suggested for submodule '%s'\n"),
 379                                 sub->name);
 380                         upd = xstrdup("none");
 381                 } else
 382                         upd = xstrdup(submodule_strategy_to_string(&sub->update_strategy));
 383
 384                 if (git_config_set_gently(sb.buf, upd))
 385                         die(_("Failed to register update mode for submodule path '%s'"), displaypath);
 386         }
 387         strbuf_release(&sb);
 388         free(displaypath);
 389         free(url);
 390         free(upd);
 391 }
 392
 393 static int module_init(int argc, const char **argv, const char *prefix)
 394 {
 395         struct pathspec pathspec;
 396         struct module_list list = MODULE_LIST_INIT;
 397         int quiet = 0;
 398         int i;
 399
 400         struct option module_init_options[] = {
 401                 OPT_STRING(0, "prefix", &prefix,
 402                            N_("path"),
 403                            N_("alternative anchor for relative paths")),
 404                 OPT__QUIET(&quiet, N_("Suppress output for initializing a submodule")),
 405                 OPT_END()
 406         };
 407
 408         const char *const git_submodule_helper_usage[] = {
 409                 N_("git submodule--helper init [<path>]"),
 410                 NULL
 411         };
 412
 413         argc = parse_options(argc, argv, prefix, module_init_options,
 414                              git_submodule_helper_usage, 0);
 415
 416         if (module_list_compute(argc, argv, prefix, &pathspec, &list) < 0)
 417                 return 1;
 418
 419         for (i = 0; i < list.nr; i++)
 420                 init_submodule(list.entries[i]->name, prefix, quiet);
 421
 422         return 0;
 423 }
 424
 425 static int module_name(int argc, const char **argv, const char *prefix)
 426 {
 427         const struct submodule *sub;
 428
 429         if (argc != 2)
 430                 usage(_("git submodule--helper name <path>"));
 431
 432         gitmodules_config();
 433         sub = submodule_from_path(null_sha1, argv[1]);
 434
 435         if (!sub)
 436                 die(_("no submodule mapping found in .gitmodules for path '%s'"),
 437                     argv[1]);
 438
 439         printf("%s\n", sub->name);
 440
 441         return 0;
 442 }
 443
 444 static int clone_submodule(const char *path, const char *gitdir, const char *url,
 445                            const char *depth, const char *reference, int quiet)
 446 {
 447         struct child_process cp = CHILD_PROCESS_INIT;
 448
 449         argv_array_push(&cp.args, "clone");
 450         argv_array_push(&cp.args, "--no-checkout");
 451         if (quiet)
 452                 argv_array_push(&cp.args, "--quiet");
 453         if (depth && *depth)
 454                 argv_array_pushl(&cp.args, "--depth", depth, NULL);
 455         if (reference && *reference)
 456                 argv_array_pushl(&cp.args, "--reference", reference, NULL);
 457         if (gitdir && *gitdir)
 458                 argv_array_pushl(&cp.args, "--separate-git-dir", gitdir, NULL);
 459
 460         argv_array_push(&cp.args, url);
 461         argv_array_push(&cp.args, path);
 462
 463         cp.git_cmd = 1;
 464         prepare_submodule_repo_env(&cp.env_array);
 465         cp.no_stdin = 1;
 466
 467         return run_command(&cp);
 468 }
 469
 470 static int module_clone(int argc, const char **argv, const char *prefix)
 471 {
 472         const char *name = NULL, *url = NULL;
 473         const char *reference = NULL, *depth = NULL;
 474         int quiet = 0;
 475         FILE *submodule_dot_git;
 476         char *p, *path = NULL, *sm_gitdir;
 477         struct strbuf rel_path = STRBUF_INIT;
 478         struct strbuf sb = STRBUF_INIT;
 479
 480         struct option module_clone_options[] = {
 481                 OPT_STRING(0, "prefix", &prefix,
 482                            N_("path"),
 483                            N_("alternative anchor for relative paths")),
 484                 OPT_STRING(0, "path", &path,
 485                            N_("path"),
 486                            N_("where the new submodule will be cloned to")),
 487                 OPT_STRING(0, "name", &name,
 488                            N_("string"),
 489                            N_("name of the new submodule")),
 490                 OPT_STRING(0, "url", &url,
 491                            N_("string"),
 492                            N_("url where to clone the submodule from")),
 493                 OPT_STRING(0, "reference", &reference,
 494                            N_("string"),
 495                            N_("reference repository")),
 496                 OPT_STRING(0, "depth", &depth,
 497                            N_("string"),
 498                            N_("depth for shallow clones")),
 499                 OPT__QUIET(&quiet, "Suppress output for cloning a submodule"),
 500                 OPT_END()
 501         };
 502
 503         const char *const git_submodule_helper_usage[] = {
 504                 N_("git submodule--helper clone [--prefix=<path>] [--quiet] "
 505                    "[--reference <repository>] [--name <name>] [--depth <depth>] "
 506                    "--url <url> --path <path>"),
 507                 NULL
 508         };
 509
 510         argc = parse_options(argc, argv, prefix, module_clone_options,
 511                              git_submodule_helper_usage, 0);
 512
 513         if (argc || !url || !path || !*path)
 514                 usage_with_options(git_submodule_helper_usage,
 515                                    module_clone_options);
 516
 517         strbuf_addf(&sb, "%s/modules/%s", get_git_dir(), name);
 518         sm_gitdir = xstrdup(absolute_path(sb.buf));
 519         strbuf_reset(&sb);
 520
 521         if (!is_absolute_path(path)) {
 522                 strbuf_addf(&sb, "%s/%s", get_git_work_tree(), path);
 523                 path = strbuf_detach(&sb, NULL);
 524         } else
 525                 path = xstrdup(path);
 526
 527         if (!file_exists(sm_gitdir)) {
 528                 if (safe_create_leading_directories_const(sm_gitdir) < 0)
 529                         die(_("could not create directory '%s'"), sm_gitdir);
 530                 if (clone_submodule(path, sm_gitdir, url, depth, reference, quiet))
 531                         die(_("clone of '%s' into submodule path '%s' failed"),
 532                             url, path);
 533         } else {
 534                 if (safe_create_leading_directories_const(path) < 0)
 535                         die(_("could not create directory '%s'"), path);
 536                 strbuf_addf(&sb, "%s/index", sm_gitdir);
 537                 unlink_or_warn(sb.buf);
 538                 strbuf_reset(&sb);
 539         }
 540
 541         /* Write a .git file in the submodule to redirect to the superproject. */
 542         strbuf_addf(&sb, "%s/.git", path);
 543         if (safe_create_leading_directories_const(sb.buf) < 0)
 544                 die(_("could not create leading directories of '%s'"), sb.buf);
 545         submodule_dot_git = fopen(sb.buf, "w");
 546         if (!submodule_dot_git)
 547                 die_errno(_("cannot open file '%s'"), sb.buf);
 548
 549         fprintf_or_die(submodule_dot_git, "gitdir: %s\n",
 550                        relative_path(sm_gitdir, path, &rel_path));
 551         if (fclose(submodule_dot_git))
 552                 die(_("could not close file %s"), sb.buf);
 553         strbuf_reset(&sb);
 554         strbuf_reset(&rel_path);
 555
 556         /* Redirect the worktree of the submodule in the superproject's config */
 557         p = git_pathdup_submodule(path, "config");
 558         if (!p)
 559                 die(_("could not get submodule directory for '%s'"), path);
 560         git_config_set_in_file(p, "core.worktree",
 561                                relative_path(path, sm_gitdir, &rel_path));
 562         strbuf_release(&sb);
 563         strbuf_release(&rel_path);
 564         free(sm_gitdir);
 565         free(path);
 566         free(p);
 567         return 0;
 568 }
 569
 570 struct submodule_update_clone {
 571         /* index into 'list', the list of submodules to look into for cloning */
 572         int current;
 573         struct module_list list;
 574         unsigned warn_if_uninitialized : 1;
 575
 576         /* update parameter passed via commandline */
 577         struct submodule_update_strategy update;
 578
 579         /* configuration parameters which are passed on to the children */
 580         int quiet;
 581         int recommend_shallow;
 582         const char *reference;
 583         const char *depth;
 584         const char *recursive_prefix;
 585         const char *prefix;
 586
 587         /* Machine-readable status lines to be consumed by git-submodule.sh */
 588         struct string_list projectlines;
 589
 590         /* If we want to stop as fast as possible and return an error */
 591         unsigned quickstop : 1;
 592
 593         /* failed clones to be retried again */
 594         const struct cache_entry **failed_clones;
 595         int failed_clones_nr, failed_clones_alloc;
 596 };
 597 #define SUBMODULE_UPDATE_CLONE_INIT {0, MODULE_LIST_INIT, 0, \
 598         SUBMODULE_UPDATE_STRATEGY_INIT, 0, -1, NULL, NULL, NULL, NULL, \
 599         STRING_LIST_INIT_DUP, 0, NULL, 0, 0}
 600
 601
 602 static void next_submodule_warn_missing(struct submodule_update_clone *suc,
 603                 struct strbuf *out, const char *displaypath)
 604 {
 605         /*
 606          * Only mention uninitialized submodules when their
 607          * paths have been specified.
 608          */
 609         if (suc->warn_if_uninitialized) {
 610                 strbuf_addf(out,
 611                         _("Submodule path '%s' not initialized"),
 612                         displaypath);
 613                 strbuf_addch(out, '\n');
 614                 strbuf_addstr(out,
 615                         _("Maybe you want to use 'update --init'?"));
 616                 strbuf_addch(out, '\n');
 617         }
 618 }
 619
 620 /**
 621  * Determine whether 'ce' needs to be cloned. If so, prepare the 'child' to
 622  * run the clone. Returns 1 if 'ce' needs to be cloned, 0 otherwise.
 623  */
 624 static int prepare_to_clone_next_submodule(const struct cache_entry *ce,
 625                                            struct child_process *child,
 626                                            struct submodule_update_clone *suc,
 627                                            struct strbuf *out)
 628 {
 629         const struct submodule *sub = NULL;
 630         struct strbuf displaypath_sb = STRBUF_INIT;
 631         struct strbuf sb = STRBUF_INIT;
 632         const char *displaypath = NULL;
 633         char *url = NULL;
 634         int needs_cloning = 0;
 635
 636         if (ce_stage(ce)) {
 637                 if (suc->recursive_prefix)
 638                         strbuf_addf(&sb, "%s/%s", suc->recursive_prefix, ce->name);
 639                 else
 640                         strbuf_addstr(&sb, ce->name);
 641                 strbuf_addf(out, _("Skipping unmerged submodule %s"), sb.buf);
 642                 strbuf_addch(out, '\n');
 643                 goto cleanup;
 644         }
 645
 646         sub = submodule_from_path(null_sha1, ce->name);
 647
 648         if (suc->recursive_prefix)
 649                 displaypath = relative_path(suc->recursive_prefix,
 650                                             ce->name, &displaypath_sb);
 651         else
 652                 displaypath = ce->name;
 653
 654         if (!sub) {
 655                 next_submodule_warn_missing(suc, out, displaypath);
 656                 goto cleanup;
 657         }
 658
 659         if (suc->update.type == SM_UPDATE_NONE
 660             || (suc->update.type == SM_UPDATE_UNSPECIFIED
 661                 && sub->update_strategy.type == SM_UPDATE_NONE)) {
 662                 strbuf_addf(out, _("Skipping submodule '%s'"), displaypath);
 663                 strbuf_addch(out, '\n');
 664                 goto cleanup;
 665         }
 666
 667         /*
 668          * Looking up the url in .git/config.
 669          * We must not fall back to .gitmodules as we only want
 670          * to process configured submodules.
 671          */
 672         strbuf_reset(&sb);
 673         strbuf_addf(&sb, "submodule.%s.url", sub->name);
 674         git_config_get_string(sb.buf, &url);
 675         if (!url) {
 676                 next_submodule_warn_missing(suc, out, displaypath);
 677                 goto cleanup;
 678         }
 679
 680         strbuf_reset(&sb);
 681         strbuf_addf(&sb, "%s/.git", ce->name);
 682         needs_cloning = !file_exists(sb.buf);
 683
 684         strbuf_reset(&sb);
 685         strbuf_addf(&sb, "%06o %s %d %d\t%s\n", ce->ce_mode,
 686                         sha1_to_hex(ce->sha1), ce_stage(ce),
 687                         needs_cloning, ce->name);
 688         string_list_append(&suc->projectlines, sb.buf);
 689
 690         if (!needs_cloning)
 691                 goto cleanup;
 692
 693         child->git_cmd = 1;
 694         child->no_stdin = 1;
 695         child->stdout_to_stderr = 1;
 696         child->err = -1;
 697         argv_array_push(&child->args, "submodule--helper");
 698         argv_array_push(&child->args, "clone");
 699         if (suc->quiet)
 700                 argv_array_push(&child->args, "--quiet");
 701         if (suc->prefix)
 702                 argv_array_pushl(&child->args, "--prefix", suc->prefix, NULL);
 703         if (suc->recommend_shallow && sub->recommend_shallow == 1)
 704                 argv_array_push(&child->args, "--depth=1");
 705         argv_array_pushl(&child->args, "--path", sub->path, NULL);
 706         argv_array_pushl(&child->args, "--name", sub->name, NULL);
 707         argv_array_pushl(&child->args, "--url", url, NULL);
 708         if (suc->reference)
 709                 argv_array_push(&child->args, suc->reference);
 710         if (suc->depth)
 711                 argv_array_push(&child->args, suc->depth);
 712
 713 cleanup:
 714         free(url);
 715         strbuf_reset(&displaypath_sb);
 716         strbuf_reset(&sb);
 717
 718         return needs_cloning;
 719 }
 720
 721 static int update_clone_get_next_task(struct child_process *child,
 722                                       struct strbuf *err,
 723                                       void *suc_cb,
 724                                       void **idx_task_cb)
 725 {
 726         struct submodule_update_clone *suc = suc_cb;
 727         const struct cache_entry *ce;
 728         int index;
 729
 730         for (; suc->current < suc->list.nr; suc->current++) {
 731                 ce = suc->list.entries[suc->current];
 732                 if (prepare_to_clone_next_submodule(ce, child, suc, err)) {
 733                         int *p = xmalloc(sizeof(*p));
 734                         *p = suc->current;
 735                         *idx_task_cb = p;
 736                         suc->current++;
 737                         return 1;
 738                 }
 739         }
 740
 741         /*
 742          * The loop above tried cloning each submodule once, now try the
 743          * stragglers again, which we can imagine as an extension of the
 744          * entry list.
 745          */
 746         index = suc->current - suc->list.nr;
 747         if (index < suc->failed_clones_nr) {
 748                 int *p;
 749                 ce = suc->failed_clones[index];
 750                 if (!prepare_to_clone_next_submodule(ce, child, suc, err)) {
 751                         suc->current ++;
 752                         strbuf_addstr(err, "BUG: submodule considered for "
 753                                            "cloning, doesn't need cloning "
 754                                            "any more?\n");
 755                         return 0;
 756                 }
 757                 p = xmalloc(sizeof(*p));
 758                 *p = suc->current;
 759                 *idx_task_cb = p;
 760                 suc->current ++;
 761                 return 1;
 762         }
 763
 764         return 0;
 765 }
 766
 767 static int update_clone_start_failure(struct strbuf *err,
 768                                       void *suc_cb,
 769                                       void *idx_task_cb)
 770 {
 771         struct submodule_update_clone *suc = suc_cb;
 772         suc->quickstop = 1;
 773         return 1;
 774 }
 775
 776 static int update_clone_task_finished(int result,
 777                                       struct strbuf *err,
 778                                       void *suc_cb,
 779                                       void *idx_task_cb)
 780 {
 781         const struct cache_entry *ce;
 782         struct submodule_update_clone *suc = suc_cb;
 783
 784         int *idxP = *(int**)idx_task_cb;
 785         int idx = *idxP;
 786         free(idxP);
 787
 788         if (!result)
 789                 return 0;
 790
 791         if (idx < suc->list.nr) {
 792                 ce  = suc->list.entries[idx];
 793                 strbuf_addf(err, _("Failed to clone '%s'. Retry scheduled"),
 794                             ce->name);
 795                 strbuf_addch(err, '\n');
 796                 ALLOC_GROW(suc->failed_clones,
 797                            suc->failed_clones_nr + 1,
 798                            suc->failed_clones_alloc);
 799                 suc->failed_clones[suc->failed_clones_nr++] = ce;
 800                 return 0;
 801         } else {
 802                 idx -= suc->list.nr;
 803                 ce  = suc->failed_clones[idx];
 804                 strbuf_addf(err, _("Failed to clone '%s' a second time, aborting"),
 805                             ce->name);
 806                 strbuf_addch(err, '\n');
 807                 suc->quickstop = 1;
 808                 return 1;
 809         }
 810
 811         return 0;
 812 }
 813
 814 static int update_clone(int argc, const char **argv, const char *prefix)
 815 {
 816         const char *update = NULL;
 817         int max_jobs = -1;
 818         struct string_list_item *item;
 819         struct pathspec pathspec;
 820         struct submodule_update_clone suc = SUBMODULE_UPDATE_CLONE_INIT;
 821
 822         struct option module_update_clone_options[] = {
 823                 OPT_STRING(0, "prefix", &prefix,
 824                            N_("path"),
 825                            N_("path into the working tree")),
 826                 OPT_STRING(0, "recursive-prefix", &suc.recursive_prefix,
 827                            N_("path"),
 828                            N_("path into the working tree, across nested "
 829                               "submodule boundaries")),
 830                 OPT_STRING(0, "update", &update,
 831                            N_("string"),
 832                            N_("rebase, merge, checkout or none")),
 833                 OPT_STRING(0, "reference", &suc.reference, N_("repo"),
 834                            N_("reference repository")),
 835                 OPT_STRING(0, "depth", &suc.depth, "<depth>",
 836                            N_("Create a shallow clone truncated to the "
 837                               "specified number of revisions")),
 838                 OPT_INTEGER('j', "jobs", &max_jobs,
 839                             N_("parallel jobs")),
 840                 OPT_BOOL(0, "recommend-shallow", &suc.recommend_shallow,
 841                             N_("whether the initial clone should follow the shallow recommendation")),
 842                 OPT__QUIET(&suc.quiet, N_("don't print cloning progress")),
 843                 OPT_END()
 844         };
 845
 846         const char *const git_submodule_helper_usage[] = {
 847                 N_("git submodule--helper update_clone [--prefix=<path>] [<path>...]"),
 848                 NULL
 849         };
 850         suc.prefix = prefix;
 851
 852         argc = parse_options(argc, argv, prefix, module_update_clone_options,
 853                              git_submodule_helper_usage, 0);
 854
 855         if (update)
 856                 if (parse_submodule_update_strategy(update, &suc.update) < 0)
 857                         die(_("bad value for update parameter"));
 858
 859         if (module_list_compute(argc, argv, prefix, &pathspec, &suc.list) < 0)
 860                 return 1;
 861
 862         if (pathspec.nr)
 863                 suc.warn_if_uninitialized = 1;
 864
 865         /* Overlay the parsed .gitmodules file with .git/config */
 866         gitmodules_config();
 867         git_config(submodule_config, NULL);
 868
 869         if (max_jobs < 0)
 870                 max_jobs = parallel_submodules();
 871
 872         run_processes_parallel(max_jobs,
 873                                update_clone_get_next_task,
 874                                update_clone_start_failure,
 875                                update_clone_task_finished,
 876                                &suc);
 877
 878         /*
 879          * We saved the output and put it out all at once now.
 880          * That means:
 881          * - the listener does not have to interleave their (checkout)
 882          *   work with our fetching.  The writes involved in a
 883          *   checkout involve more straightforward sequential I/O.
 884          * - the listener can avoid doing any work if fetching failed.
 885          */
 886         if (suc.quickstop)
 887                 return 1;
 888
 889         for_each_string_list_item(item, &suc.projectlines)
 890                 utf8_fprintf(stdout, "%s", item->string);
 891
 892         return 0;
 893 }
 894
 895 static int resolve_relative_path(int argc, const char **argv, const char *prefix)
 896 {
 897         struct strbuf sb = STRBUF_INIT;
 898         if (argc != 3)
 899                 die("submodule--helper relative-path takes exactly 2 arguments, got %d", argc);
 900
 901         printf("%s", relative_path(argv[1], argv[2], &sb));
 902         strbuf_release(&sb);
 903         return 0;
 904 }
 905
 906 static const char *remote_submodule_branch(const char *path)
 907 {
 908         const struct submodule *sub;
 909         gitmodules_config();
 910         git_config(submodule_config, NULL);
 911
 912         sub = submodule_from_path(null_sha1, path);
 913         if (!sub)
 914                 return NULL;
 915
 916         if (!sub->branch)
 917                 return "master";
 918
 919         if (!strcmp(sub->branch, ".")) {
 920                 unsigned char sha1[20];
 921                 const char *refname = resolve_ref_unsafe("HEAD", 0, sha1, NULL);
 922
 923                 if (!refname)
 924                         die(_("No such ref: %s"), "HEAD");
 925
 926                 /* detached HEAD */
 927                 if (!strcmp(refname, "HEAD"))
 928                         die(_("Submodule (%s) branch configured to inherit "
 929                               "branch from superproject, but the superproject "
 930                               "is not on any branch"), sub->name);
 931
 932                 if (!skip_prefix(refname, "refs/heads/", &refname))
 933                         die(_("Expecting a full ref name, got %s"), refname);
 934                 return refname;
 935         }
 936
 937         return sub->branch;
 938 }
 939
 940 static int resolve_remote_submodule_branch(int argc, const char **argv,
 941                 const char *prefix)
 942 {
 943         const char *ret;
 944         struct strbuf sb = STRBUF_INIT;
 945         if (argc != 2)
 946                 die("submodule--helper remote-branch takes exactly one arguments, got %d", argc);
 947
 948         ret = remote_submodule_branch(argv[1]);
 949         if (!ret)
 950                 die("submodule %s doesn't exist", argv[1]);
 951
 952         printf("%s", ret);
 953         strbuf_release(&sb);
 954         return 0;
 955 }
 956
 957 struct cmd_struct {
 958         const char *cmd;
 959         int (*fn)(int, const char **, const char *);
 960 };
 961
 962 static struct cmd_struct commands[] = {
 963         {"list", module_list},
 964         {"name", module_name},
 965         {"clone", module_clone},
 966         {"update-clone", update_clone},
 967         {"relative-path", resolve_relative_path},
 968         {"resolve-relative-url", resolve_relative_url},
 969         {"resolve-relative-url-test", resolve_relative_url_test},
 970         {"init", module_init},
 971         {"remote-branch", resolve_remote_submodule_branch}
 972 };
 973
 974 int cmd_submodule__helper(int argc, const char **argv, const char *prefix)
 975 {
 976         int i;
 977         if (argc < 2)
 978                 die(_("submodule--helper subcommand must be "
 979                       "called with a subcommand"));
 980
 981         for (i = 0; i < ARRAY_SIZE(commands); i++)
 982                 if (!strcmp(argv[1], commands[i].cmd))
 983                         return commands[i].fn(argc - 1, argv + 1, prefix);
 984
 985         die(_("'%s' is not a valid submodule--helper "
 986               "subcommand"), argv[1]);
 987 }