Andrew's git / gitweb.git / submodule.c
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submodule.con commit implement fetching of moved submodules (c68f837)
   1#include "cache.h"
   2#include "repository.h"
   3#include "config.h"
   4#include "submodule-config.h"
   5#include "submodule.h"
   6#include "dir.h"
   7#include "diff.h"
   8#include "commit.h"
   9#include "revision.h"
  10#include "run-command.h"
  11#include "diffcore.h"
  12#include "refs.h"
  13#include "string-list.h"
  14#include "sha1-array.h"
  15#include "argv-array.h"
  16#include "blob.h"
  17#include "thread-utils.h"
  18#include "quote.h"
  19#include "remote.h"
  20#include "worktree.h"
  21#include "parse-options.h"
  22
  23static int config_update_recurse_submodules = RECURSE_SUBMODULES_OFF;
  24static struct string_list changed_submodule_names = STRING_LIST_INIT_DUP;
  25static int initialized_fetch_ref_tips;
  26static struct oid_array ref_tips_before_fetch;
  27static struct oid_array ref_tips_after_fetch;
  28
  29/*
  30 * Check if the .gitmodules file is unmerged. Parsing of the .gitmodules file
  31 * will be disabled because we can't guess what might be configured in
  32 * .gitmodules unless the user resolves the conflict.
  33 */
  34int is_gitmodules_unmerged(const struct index_state *istate)
  35{
  36        int pos = index_name_pos(istate, GITMODULES_FILE, strlen(GITMODULES_FILE));
  37        if (pos < 0) { /* .gitmodules not found or isn't merged */
  38                pos = -1 - pos;
  39                if (istate->cache_nr > pos) {  /* there is a .gitmodules */
  40                        const struct cache_entry *ce = istate->cache[pos];
  41                        if (ce_namelen(ce) == strlen(GITMODULES_FILE) &&
  42                            !strcmp(ce->name, GITMODULES_FILE))
  43                                return 1;
  44                }
  45        }
  46
  47        return 0;
  48}
  49
  50/*
  51 * Check if the .gitmodules file has unstaged modifications.  This must be
  52 * checked before allowing modifications to the .gitmodules file with the
  53 * intention to stage them later, because when continuing we would stage the
  54 * modifications the user didn't stage herself too. That might change in a
  55 * future version when we learn to stage the changes we do ourselves without
  56 * staging any previous modifications.
  57 */
  58int is_staging_gitmodules_ok(const struct index_state *istate)
  59{
  60        int pos = index_name_pos(istate, GITMODULES_FILE, strlen(GITMODULES_FILE));
  61
  62        if ((pos >= 0) && (pos < istate->cache_nr)) {
  63                struct stat st;
  64                if (lstat(GITMODULES_FILE, &st) == 0 &&
  65                    ce_match_stat(istate->cache[pos], &st, 0) & DATA_CHANGED)
  66                        return 0;
  67        }
  68
  69        return 1;
  70}
  71
  72static int for_each_remote_ref_submodule(const char *submodule,
  73                                         each_ref_fn fn, void *cb_data)
  74{
  75        return refs_for_each_remote_ref(get_submodule_ref_store(submodule),
  76                                        fn, cb_data);
  77}
  78
  79/*
  80 * Try to update the "path" entry in the "submodule.<name>" section of the
  81 * .gitmodules file. Return 0 only if a .gitmodules file was found, a section
  82 * with the correct path=<oldpath> setting was found and we could update it.
  83 */
  84int update_path_in_gitmodules(const char *oldpath, const char *newpath)
  85{
  86        struct strbuf entry = STRBUF_INIT;
  87        const struct submodule *submodule;
  88
  89        if (!file_exists(GITMODULES_FILE)) /* Do nothing without .gitmodules */
  90                return -1;
  91
  92        if (is_gitmodules_unmerged(&the_index))
  93                die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
  94
  95        submodule = submodule_from_path(&null_oid, oldpath);
  96        if (!submodule || !submodule->name) {
  97                warning(_("Could not find section in .gitmodules where path=%s"), oldpath);
  98                return -1;
  99        }
 100        strbuf_addstr(&entry, "submodule.");
 101        strbuf_addstr(&entry, submodule->name);
 102        strbuf_addstr(&entry, ".path");
 103        if (git_config_set_in_file_gently(GITMODULES_FILE, entry.buf, newpath) < 0) {
 104                /* Maybe the user already did that, don't error out here */
 105                warning(_("Could not update .gitmodules entry %s"), entry.buf);
 106                strbuf_release(&entry);
 107                return -1;
 108        }
 109        strbuf_release(&entry);
 110        return 0;
 111}
 112
 113/*
 114 * Try to remove the "submodule.<name>" section from .gitmodules where the given
 115 * path is configured. Return 0 only if a .gitmodules file was found, a section
 116 * with the correct path=<path> setting was found and we could remove it.
 117 */
 118int remove_path_from_gitmodules(const char *path)
 119{
 120        struct strbuf sect = STRBUF_INIT;
 121        const struct submodule *submodule;
 122
 123        if (!file_exists(GITMODULES_FILE)) /* Do nothing without .gitmodules */
 124                return -1;
 125
 126        if (is_gitmodules_unmerged(&the_index))
 127                die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
 128
 129        submodule = submodule_from_path(&null_oid, path);
 130        if (!submodule || !submodule->name) {
 131                warning(_("Could not find section in .gitmodules where path=%s"), path);
 132                return -1;
 133        }
 134        strbuf_addstr(&sect, "submodule.");
 135        strbuf_addstr(&sect, submodule->name);
 136        if (git_config_rename_section_in_file(GITMODULES_FILE, sect.buf, NULL) < 0) {
 137                /* Maybe the user already did that, don't error out here */
 138                warning(_("Could not remove .gitmodules entry for %s"), path);
 139                strbuf_release(&sect);
 140                return -1;
 141        }
 142        strbuf_release(&sect);
 143        return 0;
 144}
 145
 146void stage_updated_gitmodules(void)
 147{
 148        if (add_file_to_cache(GITMODULES_FILE, 0))
 149                die(_("staging updated .gitmodules failed"));
 150}
 151
 152static int add_submodule_odb(const char *path)
 153{
 154        struct strbuf objects_directory = STRBUF_INIT;
 155        int ret = 0;
 156
 157        ret = strbuf_git_path_submodule(&objects_directory, path, "objects/");
 158        if (ret)
 159                goto done;
 160        if (!is_directory(objects_directory.buf)) {
 161                ret = -1;
 162                goto done;
 163        }
 164        add_to_alternates_memory(objects_directory.buf);
 165done:
 166        strbuf_release(&objects_directory);
 167        return ret;
 168}
 169
 170void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
 171                                             const char *path)
 172{
 173        const struct submodule *submodule = submodule_from_path(&null_oid, path);
 174        if (submodule) {
 175                const char *ignore;
 176                char *key;
 177
 178                key = xstrfmt("submodule.%s.ignore", submodule->name);
 179                if (repo_config_get_string_const(the_repository, key, &ignore))
 180                        ignore = submodule->ignore;
 181                free(key);
 182
 183                if (ignore)
 184                        handle_ignore_submodules_arg(diffopt, ignore);
 185                else if (is_gitmodules_unmerged(&the_index))
 186                        DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
 187        }
 188}
 189
 190/* Cheap function that only determines if we're interested in submodules at all */
 191int git_default_submodule_config(const char *var, const char *value, void *cb)
 192{
 193        if (!strcmp(var, "submodule.recurse")) {
 194                int v = git_config_bool(var, value) ?
 195                        RECURSE_SUBMODULES_ON : RECURSE_SUBMODULES_OFF;
 196                config_update_recurse_submodules = v;
 197        }
 198        return 0;
 199}
 200
 201int option_parse_recurse_submodules_worktree_updater(const struct option *opt,
 202                                                     const char *arg, int unset)
 203{
 204        if (unset) {
 205                config_update_recurse_submodules = RECURSE_SUBMODULES_OFF;
 206                return 0;
 207        }
 208        if (arg)
 209                config_update_recurse_submodules =
 210                        parse_update_recurse_submodules_arg(opt->long_name,
 211                                                            arg);
 212        else
 213                config_update_recurse_submodules = RECURSE_SUBMODULES_ON;
 214
 215        return 0;
 216}
 217
 218/*
 219 * Determine if a submodule has been initialized at a given 'path'
 220 */
 221int is_submodule_active(struct repository *repo, const char *path)
 222{
 223        int ret = 0;
 224        char *key = NULL;
 225        char *value = NULL;
 226        const struct string_list *sl;
 227        const struct submodule *module;
 228
 229        module = submodule_from_cache(repo, &null_oid, path);
 230
 231        /* early return if there isn't a path->module mapping */
 232        if (!module)
 233                return 0;
 234
 235        /* submodule.<name>.active is set */
 236        key = xstrfmt("submodule.%s.active", module->name);
 237        if (!repo_config_get_bool(repo, key, &ret)) {
 238                free(key);
 239                return ret;
 240        }
 241        free(key);
 242
 243        /* submodule.active is set */
 244        sl = repo_config_get_value_multi(repo, "submodule.active");
 245        if (sl) {
 246                struct pathspec ps;
 247                struct argv_array args = ARGV_ARRAY_INIT;
 248                const struct string_list_item *item;
 249
 250                for_each_string_list_item(item, sl) {
 251                        argv_array_push(&args, item->string);
 252                }
 253
 254                parse_pathspec(&ps, 0, 0, NULL, args.argv);
 255                ret = match_pathspec(&ps, path, strlen(path), 0, NULL, 1);
 256
 257                argv_array_clear(&args);
 258                clear_pathspec(&ps);
 259                return ret;
 260        }
 261
 262        /* fallback to checking if the URL is set */
 263        key = xstrfmt("submodule.%s.url", module->name);
 264        ret = !repo_config_get_string(repo, key, &value);
 265
 266        free(value);
 267        free(key);
 268        return ret;
 269}
 270
 271int is_submodule_populated_gently(const char *path, int *return_error_code)
 272{
 273        int ret = 0;
 274        char *gitdir = xstrfmt("%s/.git", path);
 275
 276        if (resolve_gitdir_gently(gitdir, return_error_code))
 277                ret = 1;
 278
 279        free(gitdir);
 280        return ret;
 281}
 282
 283/*
 284 * Dies if the provided 'prefix' corresponds to an unpopulated submodule
 285 */
 286void die_in_unpopulated_submodule(const struct index_state *istate,
 287                                  const char *prefix)
 288{
 289        int i, prefixlen;
 290
 291        if (!prefix)
 292                return;
 293
 294        prefixlen = strlen(prefix);
 295
 296        for (i = 0; i < istate->cache_nr; i++) {
 297                struct cache_entry *ce = istate->cache[i];
 298                int ce_len = ce_namelen(ce);
 299
 300                if (!S_ISGITLINK(ce->ce_mode))
 301                        continue;
 302                if (prefixlen <= ce_len)
 303                        continue;
 304                if (strncmp(ce->name, prefix, ce_len))
 305                        continue;
 306                if (prefix[ce_len] != '/')
 307                        continue;
 308
 309                die(_("in unpopulated submodule '%s'"), ce->name);
 310        }
 311}
 312
 313/*
 314 * Dies if any paths in the provided pathspec descends into a submodule
 315 */
 316void die_path_inside_submodule(const struct index_state *istate,
 317                               const struct pathspec *ps)
 318{
 319        int i, j;
 320
 321        for (i = 0; i < istate->cache_nr; i++) {
 322                struct cache_entry *ce = istate->cache[i];
 323                int ce_len = ce_namelen(ce);
 324
 325                if (!S_ISGITLINK(ce->ce_mode))
 326                        continue;
 327
 328                for (j = 0; j < ps->nr ; j++) {
 329                        const struct pathspec_item *item = &ps->items[j];
 330
 331                        if (item->len <= ce_len)
 332                                continue;
 333                        if (item->match[ce_len] != '/')
 334                                continue;
 335                        if (strncmp(ce->name, item->match, ce_len))
 336                                continue;
 337                        if (item->len == ce_len + 1)
 338                                continue;
 339
 340                        die(_("Pathspec '%s' is in submodule '%.*s'"),
 341                            item->original, ce_len, ce->name);
 342                }
 343        }
 344}
 345
 346enum submodule_update_type parse_submodule_update_type(const char *value)
 347{
 348        if (!strcmp(value, "none"))
 349                return SM_UPDATE_NONE;
 350        else if (!strcmp(value, "checkout"))
 351                return SM_UPDATE_CHECKOUT;
 352        else if (!strcmp(value, "rebase"))
 353                return SM_UPDATE_REBASE;
 354        else if (!strcmp(value, "merge"))
 355                return SM_UPDATE_MERGE;
 356        else if (*value == '!')
 357                return SM_UPDATE_COMMAND;
 358        else
 359                return SM_UPDATE_UNSPECIFIED;
 360}
 361
 362int parse_submodule_update_strategy(const char *value,
 363                struct submodule_update_strategy *dst)
 364{
 365        enum submodule_update_type type;
 366
 367        free((void*)dst->command);
 368        dst->command = NULL;
 369
 370        type = parse_submodule_update_type(value);
 371        if (type == SM_UPDATE_UNSPECIFIED)
 372                return -1;
 373
 374        dst->type = type;
 375        if (type == SM_UPDATE_COMMAND)
 376                dst->command = xstrdup(value + 1);
 377
 378        return 0;
 379}
 380
 381const char *submodule_strategy_to_string(const struct submodule_update_strategy *s)
 382{
 383        struct strbuf sb = STRBUF_INIT;
 384        switch (s->type) {
 385        case SM_UPDATE_CHECKOUT:
 386                return "checkout";
 387        case SM_UPDATE_MERGE:
 388                return "merge";
 389        case SM_UPDATE_REBASE:
 390                return "rebase";
 391        case SM_UPDATE_NONE:
 392                return "none";
 393        case SM_UPDATE_UNSPECIFIED:
 394                return NULL;
 395        case SM_UPDATE_COMMAND:
 396                strbuf_addf(&sb, "!%s", s->command);
 397                return strbuf_detach(&sb, NULL);
 398        }
 399        return NULL;
 400}
 401
 402void handle_ignore_submodules_arg(struct diff_options *diffopt,
 403                                  const char *arg)
 404{
 405        DIFF_OPT_CLR(diffopt, IGNORE_SUBMODULES);
 406        DIFF_OPT_CLR(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
 407        DIFF_OPT_CLR(diffopt, IGNORE_DIRTY_SUBMODULES);
 408
 409        if (!strcmp(arg, "all"))
 410                DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
 411        else if (!strcmp(arg, "untracked"))
 412                DIFF_OPT_SET(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
 413        else if (!strcmp(arg, "dirty"))
 414                DIFF_OPT_SET(diffopt, IGNORE_DIRTY_SUBMODULES);
 415        else if (strcmp(arg, "none"))
 416                die("bad --ignore-submodules argument: %s", arg);
 417}
 418
 419static int prepare_submodule_summary(struct rev_info *rev, const char *path,
 420                struct commit *left, struct commit *right,
 421                struct commit_list *merge_bases)
 422{
 423        struct commit_list *list;
 424
 425        init_revisions(rev, NULL);
 426        setup_revisions(0, NULL, rev, NULL);
 427        rev->left_right = 1;
 428        rev->first_parent_only = 1;
 429        left->object.flags |= SYMMETRIC_LEFT;
 430        add_pending_object(rev, &left->object, path);
 431        add_pending_object(rev, &right->object, path);
 432        for (list = merge_bases; list; list = list->next) {
 433                list->item->object.flags |= UNINTERESTING;
 434                add_pending_object(rev, &list->item->object,
 435                        oid_to_hex(&list->item->object.oid));
 436        }
 437        return prepare_revision_walk(rev);
 438}
 439
 440static void print_submodule_summary(struct rev_info *rev, struct diff_options *o)
 441{
 442        static const char format[] = "  %m %s";
 443        struct strbuf sb = STRBUF_INIT;
 444        struct commit *commit;
 445
 446        while ((commit = get_revision(rev))) {
 447                struct pretty_print_context ctx = {0};
 448                ctx.date_mode = rev->date_mode;
 449                ctx.output_encoding = get_log_output_encoding();
 450                strbuf_setlen(&sb, 0);
 451                format_commit_message(commit, format, &sb, &ctx);
 452                strbuf_addch(&sb, '\n');
 453                if (commit->object.flags & SYMMETRIC_LEFT)
 454                        diff_emit_submodule_del(o, sb.buf);
 455                else
 456                        diff_emit_submodule_add(o, sb.buf);
 457        }
 458        strbuf_release(&sb);
 459}
 460
 461static void prepare_submodule_repo_env_no_git_dir(struct argv_array *out)
 462{
 463        const char * const *var;
 464
 465        for (var = local_repo_env; *var; var++) {
 466                if (strcmp(*var, CONFIG_DATA_ENVIRONMENT))
 467                        argv_array_push(out, *var);
 468        }
 469}
 470
 471void prepare_submodule_repo_env(struct argv_array *out)
 472{
 473        prepare_submodule_repo_env_no_git_dir(out);
 474        argv_array_pushf(out, "%s=%s", GIT_DIR_ENVIRONMENT,
 475                         DEFAULT_GIT_DIR_ENVIRONMENT);
 476}
 477
 478/* Helper function to display the submodule header line prior to the full
 479 * summary output. If it can locate the submodule objects directory it will
 480 * attempt to lookup both the left and right commits and put them into the
 481 * left and right pointers.
 482 */
 483static void show_submodule_header(struct diff_options *o, const char *path,
 484                struct object_id *one, struct object_id *two,
 485                unsigned dirty_submodule,
 486                struct commit **left, struct commit **right,
 487                struct commit_list **merge_bases)
 488{
 489        const char *message = NULL;
 490        struct strbuf sb = STRBUF_INIT;
 491        int fast_forward = 0, fast_backward = 0;
 492
 493        if (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED)
 494                diff_emit_submodule_untracked(o, path);
 495
 496        if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
 497                diff_emit_submodule_modified(o, path);
 498
 499        if (is_null_oid(one))
 500                message = "(new submodule)";
 501        else if (is_null_oid(two))
 502                message = "(submodule deleted)";
 503
 504        if (add_submodule_odb(path)) {
 505                if (!message)
 506                        message = "(commits not present)";
 507                goto output_header;
 508        }
 509
 510        /*
 511         * Attempt to lookup the commit references, and determine if this is
 512         * a fast forward or fast backwards update.
 513         */
 514        *left = lookup_commit_reference(one);
 515        *right = lookup_commit_reference(two);
 516
 517        /*
 518         * Warn about missing commits in the submodule project, but only if
 519         * they aren't null.
 520         */
 521        if ((!is_null_oid(one) && !*left) ||
 522             (!is_null_oid(two) && !*right))
 523                message = "(commits not present)";
 524
 525        *merge_bases = get_merge_bases(*left, *right);
 526        if (*merge_bases) {
 527                if ((*merge_bases)->item == *left)
 528                        fast_forward = 1;
 529                else if ((*merge_bases)->item == *right)
 530                        fast_backward = 1;
 531        }
 532
 533        if (!oidcmp(one, two)) {
 534                strbuf_release(&sb);
 535                return;
 536        }
 537
 538output_header:
 539        strbuf_addf(&sb, "Submodule %s ", path);
 540        strbuf_add_unique_abbrev(&sb, one->hash, DEFAULT_ABBREV);
 541        strbuf_addstr(&sb, (fast_backward || fast_forward) ? ".." : "...");
 542        strbuf_add_unique_abbrev(&sb, two->hash, DEFAULT_ABBREV);
 543        if (message)
 544                strbuf_addf(&sb, " %s\n", message);
 545        else
 546                strbuf_addf(&sb, "%s:\n", fast_backward ? " (rewind)" : "");
 547        diff_emit_submodule_header(o, sb.buf);
 548
 549        strbuf_release(&sb);
 550}
 551
 552void show_submodule_summary(struct diff_options *o, const char *path,
 553                struct object_id *one, struct object_id *two,
 554                unsigned dirty_submodule)
 555{
 556        struct rev_info rev;
 557        struct commit *left = NULL, *right = NULL;
 558        struct commit_list *merge_bases = NULL;
 559
 560        show_submodule_header(o, path, one, two, dirty_submodule,
 561                              &left, &right, &merge_bases);
 562
 563        /*
 564         * If we don't have both a left and a right pointer, there is no
 565         * reason to try and display a summary. The header line should contain
 566         * all the information the user needs.
 567         */
 568        if (!left || !right)
 569                goto out;
 570
 571        /* Treat revision walker failure the same as missing commits */
 572        if (prepare_submodule_summary(&rev, path, left, right, merge_bases)) {
 573                diff_emit_submodule_error(o, "(revision walker failed)\n");
 574                goto out;
 575        }
 576
 577        print_submodule_summary(&rev, o);
 578
 579out:
 580        if (merge_bases)
 581                free_commit_list(merge_bases);
 582        clear_commit_marks(left, ~0);
 583        clear_commit_marks(right, ~0);
 584}
 585
 586void show_submodule_inline_diff(struct diff_options *o, const char *path,
 587                struct object_id *one, struct object_id *two,
 588                unsigned dirty_submodule)
 589{
 590        const struct object_id *old = &empty_tree_oid, *new = &empty_tree_oid;
 591        struct commit *left = NULL, *right = NULL;
 592        struct commit_list *merge_bases = NULL;
 593        struct child_process cp = CHILD_PROCESS_INIT;
 594        struct strbuf sb = STRBUF_INIT;
 595
 596        show_submodule_header(o, path, one, two, dirty_submodule,
 597                              &left, &right, &merge_bases);
 598
 599        /* We need a valid left and right commit to display a difference */
 600        if (!(left || is_null_oid(one)) ||
 601            !(right || is_null_oid(two)))
 602                goto done;
 603
 604        if (left)
 605                old = one;
 606        if (right)
 607                new = two;
 608
 609        cp.git_cmd = 1;
 610        cp.dir = path;
 611        cp.out = -1;
 612        cp.no_stdin = 1;
 613
 614        /* TODO: other options may need to be passed here. */
 615        argv_array_pushl(&cp.args, "diff", "--submodule=diff", NULL);
 616        argv_array_pushf(&cp.args, "--color=%s", want_color(o->use_color) ?
 617                         "always" : "never");
 618
 619        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
 620                argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
 621                                 o->b_prefix, path);
 622                argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
 623                                 o->a_prefix, path);
 624        } else {
 625                argv_array_pushf(&cp.args, "--src-prefix=%s%s/",
 626                                 o->a_prefix, path);
 627                argv_array_pushf(&cp.args, "--dst-prefix=%s%s/",
 628                                 o->b_prefix, path);
 629        }
 630        argv_array_push(&cp.args, oid_to_hex(old));
 631        /*
 632         * If the submodule has modified content, we will diff against the
 633         * work tree, under the assumption that the user has asked for the
 634         * diff format and wishes to actually see all differences even if they
 635         * haven't yet been committed to the submodule yet.
 636         */
 637        if (!(dirty_submodule & DIRTY_SUBMODULE_MODIFIED))
 638                argv_array_push(&cp.args, oid_to_hex(new));
 639
 640        prepare_submodule_repo_env(&cp.env_array);
 641        if (start_command(&cp))
 642                diff_emit_submodule_error(o, "(diff failed)\n");
 643
 644        while (strbuf_getwholeline_fd(&sb, cp.out, '\n') != EOF)
 645                diff_emit_submodule_pipethrough(o, sb.buf, sb.len);
 646
 647        if (finish_command(&cp))
 648                diff_emit_submodule_error(o, "(diff failed)\n");
 649
 650done:
 651        strbuf_release(&sb);
 652        if (merge_bases)
 653                free_commit_list(merge_bases);
 654        if (left)
 655                clear_commit_marks(left, ~0);
 656        if (right)
 657                clear_commit_marks(right, ~0);
 658}
 659
 660int should_update_submodules(void)
 661{
 662        return config_update_recurse_submodules == RECURSE_SUBMODULES_ON;
 663}
 664
 665const struct submodule *submodule_from_ce(const struct cache_entry *ce)
 666{
 667        if (!S_ISGITLINK(ce->ce_mode))
 668                return NULL;
 669
 670        if (!should_update_submodules())
 671                return NULL;
 672
 673        return submodule_from_path(&null_oid, ce->name);
 674}
 675
 676static struct oid_array *submodule_commits(struct string_list *submodules,
 677                                           const char *name)
 678{
 679        struct string_list_item *item;
 680
 681        item = string_list_insert(submodules, name);
 682        if (item->util)
 683                return (struct oid_array *) item->util;
 684
 685        /* NEEDSWORK: should we have oid_array_init()? */
 686        item->util = xcalloc(1, sizeof(struct oid_array));
 687        return (struct oid_array *) item->util;
 688}
 689
 690struct collect_changed_submodules_cb_data {
 691        struct string_list *changed;
 692        const struct object_id *commit_oid;
 693};
 694
 695/*
 696 * this would normally be two functions: default_name_from_path() and
 697 * path_from_default_name(). Since the default name is the same as
 698 * the submodule path we can get away with just one function which only
 699 * checks whether there is a submodule in the working directory at that
 700 * location.
 701 */
 702static const char *default_name_or_path(const char *path_or_name)
 703{
 704        int error_code;
 705
 706        if (!is_submodule_populated_gently(path_or_name, &error_code))
 707                return NULL;
 708
 709        return path_or_name;
 710}
 711
 712static void collect_changed_submodules_cb(struct diff_queue_struct *q,
 713                                          struct diff_options *options,
 714                                          void *data)
 715{
 716        struct collect_changed_submodules_cb_data *me = data;
 717        struct string_list *changed = me->changed;
 718        const struct object_id *commit_oid = me->commit_oid;
 719        int i;
 720
 721        for (i = 0; i < q->nr; i++) {
 722                struct diff_filepair *p = q->queue[i];
 723                struct oid_array *commits;
 724                const struct submodule *submodule;
 725                const char *name;
 726
 727                if (!S_ISGITLINK(p->two->mode))
 728                        continue;
 729
 730                submodule = submodule_from_path(commit_oid, p->two->path);
 731                if (submodule)
 732                        name = submodule->name;
 733                else {
 734                        name = default_name_or_path(p->two->path);
 735                        /* make sure name does not collide with existing one */
 736                        submodule = submodule_from_name(commit_oid, name);
 737                        if (submodule) {
 738                                warning("Submodule in commit %s at path: "
 739                                        "'%s' collides with a submodule named "
 740                                        "the same. Skipping it.",
 741                                        oid_to_hex(commit_oid), name);
 742                                name = NULL;
 743                        }
 744                }
 745
 746                if (!name)
 747                        continue;
 748
 749                commits = submodule_commits(changed, name);
 750                oid_array_append(commits, &p->two->oid);
 751        }
 752}
 753
 754/*
 755 * Collect the paths of submodules in 'changed' which have changed based on
 756 * the revisions as specified in 'argv'.  Each entry in 'changed' will also
 757 * have a corresponding 'struct oid_array' (in the 'util' field) which lists
 758 * what the submodule pointers were updated to during the change.
 759 */
 760static void collect_changed_submodules(struct string_list *changed,
 761                                       struct argv_array *argv)
 762{
 763        struct rev_info rev;
 764        const struct commit *commit;
 765
 766        init_revisions(&rev, NULL);
 767        setup_revisions(argv->argc, argv->argv, &rev, NULL);
 768        if (prepare_revision_walk(&rev))
 769                die("revision walk setup failed");
 770
 771        while ((commit = get_revision(&rev))) {
 772                struct rev_info diff_rev;
 773                struct collect_changed_submodules_cb_data data;
 774                data.changed = changed;
 775                data.commit_oid = &commit->object.oid;
 776
 777                init_revisions(&diff_rev, NULL);
 778                diff_rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 779                diff_rev.diffopt.format_callback = collect_changed_submodules_cb;
 780                diff_rev.diffopt.format_callback_data = &data;
 781                diff_tree_combined_merge(commit, 1, &diff_rev);
 782        }
 783
 784        reset_revision_walk();
 785}
 786
 787static void free_submodules_oids(struct string_list *submodules)
 788{
 789        struct string_list_item *item;
 790        for_each_string_list_item(item, submodules)
 791                oid_array_clear((struct oid_array *) item->util);
 792        string_list_clear(submodules, 1);
 793}
 794
 795static int has_remote(const char *refname, const struct object_id *oid,
 796                      int flags, void *cb_data)
 797{
 798        return 1;
 799}
 800
 801static int append_oid_to_argv(const struct object_id *oid, void *data)
 802{
 803        struct argv_array *argv = data;
 804        argv_array_push(argv, oid_to_hex(oid));
 805        return 0;
 806}
 807
 808struct has_commit_data {
 809        int result;
 810        const char *path;
 811};
 812
 813static int check_has_commit(const struct object_id *oid, void *data)
 814{
 815        struct has_commit_data *cb = data;
 816
 817        enum object_type type = sha1_object_info(oid->hash, NULL);
 818
 819        switch (type) {
 820        case OBJ_COMMIT:
 821                return 0;
 822        case OBJ_BAD:
 823                /*
 824                 * Object is missing or invalid. If invalid, an error message
 825                 * has already been printed.
 826                 */
 827                cb->result = 0;
 828                return 0;
 829        default:
 830                die(_("submodule entry '%s' (%s) is a %s, not a commit"),
 831                    cb->path, oid_to_hex(oid), typename(type));
 832        }
 833}
 834
 835static int submodule_has_commits(const char *path, struct oid_array *commits)
 836{
 837        struct has_commit_data has_commit = { 1, path };
 838
 839        /*
 840         * Perform a cheap, but incorrect check for the existence of 'commits'.
 841         * This is done by adding the submodule's object store to the in-core
 842         * object store, and then querying for each commit's existence.  If we
 843         * do not have the commit object anywhere, there is no chance we have
 844         * it in the object store of the correct submodule and have it
 845         * reachable from a ref, so we can fail early without spawning rev-list
 846         * which is expensive.
 847         */
 848        if (add_submodule_odb(path))
 849                return 0;
 850
 851        oid_array_for_each_unique(commits, check_has_commit, &has_commit);
 852
 853        if (has_commit.result) {
 854                /*
 855                 * Even if the submodule is checked out and the commit is
 856                 * present, make sure it exists in the submodule's object store
 857                 * and that it is reachable from a ref.
 858                 */
 859                struct child_process cp = CHILD_PROCESS_INIT;
 860                struct strbuf out = STRBUF_INIT;
 861
 862                argv_array_pushl(&cp.args, "rev-list", "-n", "1", NULL);
 863                oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
 864                argv_array_pushl(&cp.args, "--not", "--all", NULL);
 865
 866                prepare_submodule_repo_env(&cp.env_array);
 867                cp.git_cmd = 1;
 868                cp.no_stdin = 1;
 869                cp.dir = path;
 870
 871                if (capture_command(&cp, &out, GIT_MAX_HEXSZ + 1) || out.len)
 872                        has_commit.result = 0;
 873
 874                strbuf_release(&out);
 875        }
 876
 877        return has_commit.result;
 878}
 879
 880static int submodule_needs_pushing(const char *path, struct oid_array *commits)
 881{
 882        if (!submodule_has_commits(path, commits))
 883                /*
 884                 * NOTE: We do consider it safe to return "no" here. The
 885                 * correct answer would be "We do not know" instead of
 886                 * "No push needed", but it is quite hard to change
 887                 * the submodule pointer without having the submodule
 888                 * around. If a user did however change the submodules
 889                 * without having the submodule around, this indicates
 890                 * an expert who knows what they are doing or a
 891                 * maintainer integrating work from other people. In
 892                 * both cases it should be safe to skip this check.
 893                 */
 894                return 0;
 895
 896        if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 897                struct child_process cp = CHILD_PROCESS_INIT;
 898                struct strbuf buf = STRBUF_INIT;
 899                int needs_pushing = 0;
 900
 901                argv_array_push(&cp.args, "rev-list");
 902                oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args);
 903                argv_array_pushl(&cp.args, "--not", "--remotes", "-n", "1" , NULL);
 904
 905                prepare_submodule_repo_env(&cp.env_array);
 906                cp.git_cmd = 1;
 907                cp.no_stdin = 1;
 908                cp.out = -1;
 909                cp.dir = path;
 910                if (start_command(&cp))
 911                        die("Could not run 'git rev-list <commits> --not --remotes -n 1' command in submodule %s",
 912                                        path);
 913                if (strbuf_read(&buf, cp.out, 41))
 914                        needs_pushing = 1;
 915                finish_command(&cp);
 916                close(cp.out);
 917                strbuf_release(&buf);
 918                return needs_pushing;
 919        }
 920
 921        return 0;
 922}
 923
 924int find_unpushed_submodules(struct oid_array *commits,
 925                const char *remotes_name, struct string_list *needs_pushing)
 926{
 927        struct string_list submodules = STRING_LIST_INIT_DUP;
 928        struct string_list_item *name;
 929        struct argv_array argv = ARGV_ARRAY_INIT;
 930
 931        /* argv.argv[0] will be ignored by setup_revisions */
 932        argv_array_push(&argv, "find_unpushed_submodules");
 933        oid_array_for_each_unique(commits, append_oid_to_argv, &argv);
 934        argv_array_push(&argv, "--not");
 935        argv_array_pushf(&argv, "--remotes=%s", remotes_name);
 936
 937        collect_changed_submodules(&submodules, &argv);
 938
 939        for_each_string_list_item(name, &submodules) {
 940                struct oid_array *commits = name->util;
 941                const struct submodule *submodule;
 942                const char *path = NULL;
 943
 944                submodule = submodule_from_name(&null_oid, name->string);
 945                if (submodule)
 946                        path = submodule->path;
 947                else
 948                        path = default_name_or_path(name->string);
 949
 950                if (!path)
 951                        continue;
 952
 953                if (submodule_needs_pushing(path, commits))
 954                        string_list_insert(needs_pushing, path);
 955        }
 956
 957        free_submodules_oids(&submodules);
 958        argv_array_clear(&argv);
 959
 960        return needs_pushing->nr;
 961}
 962
 963static int push_submodule(const char *path,
 964                          const struct remote *remote,
 965                          const char **refspec, int refspec_nr,
 966                          const struct string_list *push_options,
 967                          int dry_run)
 968{
 969        if (add_submodule_odb(path))
 970                return 1;
 971
 972        if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 973                struct child_process cp = CHILD_PROCESS_INIT;
 974                argv_array_push(&cp.args, "push");
 975                if (dry_run)
 976                        argv_array_push(&cp.args, "--dry-run");
 977
 978                if (push_options && push_options->nr) {
 979                        const struct string_list_item *item;
 980                        for_each_string_list_item(item, push_options)
 981                                argv_array_pushf(&cp.args, "--push-option=%s",
 982                                                 item->string);
 983                }
 984
 985                if (remote->origin != REMOTE_UNCONFIGURED) {
 986                        int i;
 987                        argv_array_push(&cp.args, remote->name);
 988                        for (i = 0; i < refspec_nr; i++)
 989                                argv_array_push(&cp.args, refspec[i]);
 990                }
 991
 992                prepare_submodule_repo_env(&cp.env_array);
 993                cp.git_cmd = 1;
 994                cp.no_stdin = 1;
 995                cp.dir = path;
 996                if (run_command(&cp))
 997                        return 0;
 998                close(cp.out);
 999        }
1000
1001        return 1;
1002}
1003
1004/*
1005 * Perform a check in the submodule to see if the remote and refspec work.
1006 * Die if the submodule can't be pushed.
1007 */
1008static void submodule_push_check(const char *path, const char *head,
1009                                 const struct remote *remote,
1010                                 const char **refspec, int refspec_nr)
1011{
1012        struct child_process cp = CHILD_PROCESS_INIT;
1013        int i;
1014
1015        argv_array_push(&cp.args, "submodule--helper");
1016        argv_array_push(&cp.args, "push-check");
1017        argv_array_push(&cp.args, head);
1018        argv_array_push(&cp.args, remote->name);
1019
1020        for (i = 0; i < refspec_nr; i++)
1021                argv_array_push(&cp.args, refspec[i]);
1022
1023        prepare_submodule_repo_env(&cp.env_array);
1024        cp.git_cmd = 1;
1025        cp.no_stdin = 1;
1026        cp.no_stdout = 1;
1027        cp.dir = path;
1028
1029        /*
1030         * Simply indicate if 'submodule--helper push-check' failed.
1031         * More detailed error information will be provided by the
1032         * child process.
1033         */
1034        if (run_command(&cp))
1035                die("process for submodule '%s' failed", path);
1036}
1037
1038int push_unpushed_submodules(struct oid_array *commits,
1039                             const struct remote *remote,
1040                             const char **refspec, int refspec_nr,
1041                             const struct string_list *push_options,
1042                             int dry_run)
1043{
1044        int i, ret = 1;
1045        struct string_list needs_pushing = STRING_LIST_INIT_DUP;
1046
1047        if (!find_unpushed_submodules(commits, remote->name, &needs_pushing))
1048                return 1;
1049
1050        /*
1051         * Verify that the remote and refspec can be propagated to all
1052         * submodules.  This check can be skipped if the remote and refspec
1053         * won't be propagated due to the remote being unconfigured (e.g. a URL
1054         * instead of a remote name).
1055         */
1056        if (remote->origin != REMOTE_UNCONFIGURED) {
1057                char *head;
1058                struct object_id head_oid;
1059
1060                head = resolve_refdup("HEAD", 0, head_oid.hash, NULL);
1061                if (!head)
1062                        die(_("Failed to resolve HEAD as a valid ref."));
1063
1064                for (i = 0; i < needs_pushing.nr; i++)
1065                        submodule_push_check(needs_pushing.items[i].string,
1066                                             head, remote,
1067                                             refspec, refspec_nr);
1068                free(head);
1069        }
1070
1071        /* Actually push the submodules */
1072        for (i = 0; i < needs_pushing.nr; i++) {
1073                const char *path = needs_pushing.items[i].string;
1074                fprintf(stderr, "Pushing submodule '%s'\n", path);
1075                if (!push_submodule(path, remote, refspec, refspec_nr,
1076                                    push_options, dry_run)) {
1077                        fprintf(stderr, "Unable to push submodule '%s'\n", path);
1078                        ret = 0;
1079                }
1080        }
1081
1082        string_list_clear(&needs_pushing, 0);
1083
1084        return ret;
1085}
1086
1087static int append_oid_to_array(const char *ref, const struct object_id *oid,
1088                               int flags, void *data)
1089{
1090        struct oid_array *array = data;
1091        oid_array_append(array, oid);
1092        return 0;
1093}
1094
1095void check_for_new_submodule_commits(struct object_id *oid)
1096{
1097        if (!initialized_fetch_ref_tips) {
1098                for_each_ref(append_oid_to_array, &ref_tips_before_fetch);
1099                initialized_fetch_ref_tips = 1;
1100        }
1101
1102        oid_array_append(&ref_tips_after_fetch, oid);
1103}
1104
1105static void calculate_changed_submodule_paths(void)
1106{
1107        struct argv_array argv = ARGV_ARRAY_INIT;
1108        struct string_list changed_submodules = STRING_LIST_INIT_DUP;
1109        const struct string_list_item *name;
1110
1111        /* No need to check if there are no submodules configured */
1112        if (!submodule_from_path(NULL, NULL))
1113                return;
1114
1115        argv_array_push(&argv, "--"); /* argv[0] program name */
1116        oid_array_for_each_unique(&ref_tips_after_fetch,
1117                                   append_oid_to_argv, &argv);
1118        argv_array_push(&argv, "--not");
1119        oid_array_for_each_unique(&ref_tips_before_fetch,
1120                                   append_oid_to_argv, &argv);
1121
1122        /*
1123         * Collect all submodules (whether checked out or not) for which new
1124         * commits have been recorded upstream in "changed_submodule_names".
1125         */
1126        collect_changed_submodules(&changed_submodules, &argv);
1127
1128        for_each_string_list_item(name, &changed_submodules) {
1129                struct oid_array *commits = name->util;
1130                const struct submodule *submodule;
1131                const char *path = NULL;
1132
1133                submodule = submodule_from_name(&null_oid, name->string);
1134                if (submodule)
1135                        path = submodule->path;
1136                else
1137                        path = default_name_or_path(name->string);
1138
1139                if (!path)
1140                        continue;
1141
1142                if (!submodule_has_commits(path, commits))
1143                        string_list_append(&changed_submodule_names, name->string);
1144        }
1145
1146        free_submodules_oids(&changed_submodules);
1147        argv_array_clear(&argv);
1148        oid_array_clear(&ref_tips_before_fetch);
1149        oid_array_clear(&ref_tips_after_fetch);
1150        initialized_fetch_ref_tips = 0;
1151}
1152
1153int submodule_touches_in_range(struct object_id *excl_oid,
1154                               struct object_id *incl_oid)
1155{
1156        struct string_list subs = STRING_LIST_INIT_DUP;
1157        struct argv_array args = ARGV_ARRAY_INIT;
1158        int ret;
1159
1160        /* No need to check if there are no submodules configured */
1161        if (!submodule_from_path(NULL, NULL))
1162                return 0;
1163
1164        argv_array_push(&args, "--"); /* args[0] program name */
1165        argv_array_push(&args, oid_to_hex(incl_oid));
1166        argv_array_push(&args, "--not");
1167        argv_array_push(&args, oid_to_hex(excl_oid));
1168
1169        collect_changed_submodules(&subs, &args);
1170        ret = subs.nr;
1171
1172        argv_array_clear(&args);
1173
1174        free_submodules_oids(&subs);
1175        return ret;
1176}
1177
1178struct submodule_parallel_fetch {
1179        int count;
1180        struct argv_array args;
1181        const char *work_tree;
1182        const char *prefix;
1183        int command_line_option;
1184        int default_option;
1185        int quiet;
1186        int result;
1187};
1188#define SPF_INIT {0, ARGV_ARRAY_INIT, NULL, NULL, 0, 0, 0, 0}
1189
1190static int get_next_submodule(struct child_process *cp,
1191                              struct strbuf *err, void *data, void **task_cb)
1192{
1193        int ret = 0;
1194        struct submodule_parallel_fetch *spf = data;
1195
1196        for (; spf->count < active_nr; spf->count++) {
1197                struct strbuf submodule_path = STRBUF_INIT;
1198                struct strbuf submodule_git_dir = STRBUF_INIT;
1199                struct strbuf submodule_prefix = STRBUF_INIT;
1200                const struct cache_entry *ce = active_cache[spf->count];
1201                const char *git_dir, *default_argv;
1202                const struct submodule *submodule;
1203                struct submodule default_submodule = SUBMODULE_INIT;
1204
1205                if (!S_ISGITLINK(ce->ce_mode))
1206                        continue;
1207
1208                submodule = submodule_from_path(&null_oid, ce->name);
1209                if (!submodule) {
1210                        const char *name = default_name_or_path(ce->name);
1211                        if (name) {
1212                                default_submodule.path = default_submodule.name = name;
1213                                submodule = &default_submodule;
1214                        }
1215                }
1216
1217                default_argv = "yes";
1218                if (spf->command_line_option == RECURSE_SUBMODULES_DEFAULT) {
1219                        int fetch_recurse = RECURSE_SUBMODULES_NONE;
1220
1221                        if (submodule) {
1222                                char *key;
1223                                const char *value;
1224
1225                                fetch_recurse = submodule->fetch_recurse;
1226                                key = xstrfmt("submodule.%s.fetchRecurseSubmodules", submodule->name);
1227                                if (!repo_config_get_string_const(the_repository, key, &value)) {
1228                                        fetch_recurse = parse_fetch_recurse_submodules_arg(key, value);
1229                                }
1230                                free(key);
1231                        }
1232
1233                        if (fetch_recurse != RECURSE_SUBMODULES_NONE) {
1234                                if (fetch_recurse == RECURSE_SUBMODULES_OFF)
1235                                        continue;
1236                                if (fetch_recurse == RECURSE_SUBMODULES_ON_DEMAND) {
1237                                        if (!unsorted_string_list_lookup(&changed_submodule_names,
1238                                                                         submodule->name))
1239                                                continue;
1240                                        default_argv = "on-demand";
1241                                }
1242                        } else {
1243                                if (spf->default_option == RECURSE_SUBMODULES_OFF)
1244                                        continue;
1245                                if (spf->default_option == RECURSE_SUBMODULES_ON_DEMAND) {
1246                                        if (!unsorted_string_list_lookup(&changed_submodule_names,
1247                                                                          submodule->name))
1248                                                continue;
1249                                        default_argv = "on-demand";
1250                                }
1251                        }
1252                } else if (spf->command_line_option == RECURSE_SUBMODULES_ON_DEMAND) {
1253                        if (!unsorted_string_list_lookup(&changed_submodule_names,
1254                                                         submodule->name))
1255                                continue;
1256                        default_argv = "on-demand";
1257                }
1258
1259                strbuf_addf(&submodule_path, "%s/%s", spf->work_tree, ce->name);
1260                strbuf_addf(&submodule_git_dir, "%s/.git", submodule_path.buf);
1261                strbuf_addf(&submodule_prefix, "%s%s/", spf->prefix, ce->name);
1262                git_dir = read_gitfile(submodule_git_dir.buf);
1263                if (!git_dir)
1264                        git_dir = submodule_git_dir.buf;
1265                if (is_directory(git_dir)) {
1266                        child_process_init(cp);
1267                        cp->dir = strbuf_detach(&submodule_path, NULL);
1268                        prepare_submodule_repo_env(&cp->env_array);
1269                        cp->git_cmd = 1;
1270                        if (!spf->quiet)
1271                                strbuf_addf(err, "Fetching submodule %s%s\n",
1272                                            spf->prefix, ce->name);
1273                        argv_array_init(&cp->args);
1274                        argv_array_pushv(&cp->args, spf->args.argv);
1275                        argv_array_push(&cp->args, default_argv);
1276                        argv_array_push(&cp->args, "--submodule-prefix");
1277                        argv_array_push(&cp->args, submodule_prefix.buf);
1278                        ret = 1;
1279                }
1280                strbuf_release(&submodule_path);
1281                strbuf_release(&submodule_git_dir);
1282                strbuf_release(&submodule_prefix);
1283                if (ret) {
1284                        spf->count++;
1285                        return 1;
1286                }
1287        }
1288        return 0;
1289}
1290
1291static int fetch_start_failure(struct strbuf *err,
1292                               void *cb, void *task_cb)
1293{
1294        struct submodule_parallel_fetch *spf = cb;
1295
1296        spf->result = 1;
1297
1298        return 0;
1299}
1300
1301static int fetch_finish(int retvalue, struct strbuf *err,
1302                        void *cb, void *task_cb)
1303{
1304        struct submodule_parallel_fetch *spf = cb;
1305
1306        if (retvalue)
1307                spf->result = 1;
1308
1309        return 0;
1310}
1311
1312int fetch_populated_submodules(const struct argv_array *options,
1313                               const char *prefix, int command_line_option,
1314                               int default_option,
1315                               int quiet, int max_parallel_jobs)
1316{
1317        int i;
1318        struct submodule_parallel_fetch spf = SPF_INIT;
1319
1320        spf.work_tree = get_git_work_tree();
1321        spf.command_line_option = command_line_option;
1322        spf.default_option = default_option;
1323        spf.quiet = quiet;
1324        spf.prefix = prefix;
1325
1326        if (!spf.work_tree)
1327                goto out;
1328
1329        if (read_cache() < 0)
1330                die("index file corrupt");
1331
1332        argv_array_push(&spf.args, "fetch");
1333        for (i = 0; i < options->argc; i++)
1334                argv_array_push(&spf.args, options->argv[i]);
1335        argv_array_push(&spf.args, "--recurse-submodules-default");
1336        /* default value, "--submodule-prefix" and its value are added later */
1337
1338        calculate_changed_submodule_paths();
1339        run_processes_parallel(max_parallel_jobs,
1340                               get_next_submodule,
1341                               fetch_start_failure,
1342                               fetch_finish,
1343                               &spf);
1344
1345        argv_array_clear(&spf.args);
1346out:
1347        string_list_clear(&changed_submodule_names, 1);
1348        return spf.result;
1349}
1350
1351unsigned is_submodule_modified(const char *path, int ignore_untracked)
1352{
1353        struct child_process cp = CHILD_PROCESS_INIT;
1354        struct strbuf buf = STRBUF_INIT;
1355        FILE *fp;
1356        unsigned dirty_submodule = 0;
1357        const char *git_dir;
1358        int ignore_cp_exit_code = 0;
1359
1360        strbuf_addf(&buf, "%s/.git", path);
1361        git_dir = read_gitfile(buf.buf);
1362        if (!git_dir)
1363                git_dir = buf.buf;
1364        if (!is_git_directory(git_dir)) {
1365                if (is_directory(git_dir))
1366                        die(_("'%s' not recognized as a git repository"), git_dir);
1367                strbuf_release(&buf);
1368                /* The submodule is not checked out, so it is not modified */
1369                return 0;
1370        }
1371        strbuf_reset(&buf);
1372
1373        argv_array_pushl(&cp.args, "status", "--porcelain=2", NULL);
1374        if (ignore_untracked)
1375                argv_array_push(&cp.args, "-uno");
1376
1377        prepare_submodule_repo_env(&cp.env_array);
1378        cp.git_cmd = 1;
1379        cp.no_stdin = 1;
1380        cp.out = -1;
1381        cp.dir = path;
1382        if (start_command(&cp))
1383                die("Could not run 'git status --porcelain=2' in submodule %s", path);
1384
1385        fp = xfdopen(cp.out, "r");
1386        while (strbuf_getwholeline(&buf, fp, '\n') != EOF) {
1387                /* regular untracked files */
1388                if (buf.buf[0] == '?')
1389                        dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1390
1391                if (buf.buf[0] == 'u' ||
1392                    buf.buf[0] == '1' ||
1393                    buf.buf[0] == '2') {
1394                        /* T = line type, XY = status, SSSS = submodule state */
1395                        if (buf.len < strlen("T XY SSSS"))
1396                                die("BUG: invalid status --porcelain=2 line %s",
1397                                    buf.buf);
1398
1399                        if (buf.buf[5] == 'S' && buf.buf[8] == 'U')
1400                                /* nested untracked file */
1401                                dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
1402
1403                        if (buf.buf[0] == 'u' ||
1404                            buf.buf[0] == '2' ||
1405                            memcmp(buf.buf + 5, "S..U", 4))
1406                                /* other change */
1407                                dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
1408                }
1409
1410                if ((dirty_submodule & DIRTY_SUBMODULE_MODIFIED) &&
1411                    ((dirty_submodule & DIRTY_SUBMODULE_UNTRACKED) ||
1412                     ignore_untracked)) {
1413                        /*
1414                         * We're not interested in any further information from
1415                         * the child any more, neither output nor its exit code.
1416                         */
1417                        ignore_cp_exit_code = 1;
1418                        break;
1419                }
1420        }
1421        fclose(fp);
1422
1423        if (finish_command(&cp) && !ignore_cp_exit_code)
1424                die("'git status --porcelain=2' failed in submodule %s", path);
1425
1426        strbuf_release(&buf);
1427        return dirty_submodule;
1428}
1429
1430int submodule_uses_gitfile(const char *path)
1431{
1432        struct child_process cp = CHILD_PROCESS_INIT;
1433        const char *argv[] = {
1434                "submodule",
1435                "foreach",
1436                "--quiet",
1437                "--recursive",
1438                "test -f .git",
1439                NULL,
1440        };
1441        struct strbuf buf = STRBUF_INIT;
1442        const char *git_dir;
1443
1444        strbuf_addf(&buf, "%s/.git", path);
1445        git_dir = read_gitfile(buf.buf);
1446        if (!git_dir) {
1447                strbuf_release(&buf);
1448                return 0;
1449        }
1450        strbuf_release(&buf);
1451
1452        /* Now test that all nested submodules use a gitfile too */
1453        cp.argv = argv;
1454        prepare_submodule_repo_env(&cp.env_array);
1455        cp.git_cmd = 1;
1456        cp.no_stdin = 1;
1457        cp.no_stderr = 1;
1458        cp.no_stdout = 1;
1459        cp.dir = path;
1460        if (run_command(&cp))
1461                return 0;
1462
1463        return 1;
1464}
1465
1466/*
1467 * Check if it is a bad idea to remove a submodule, i.e. if we'd lose data
1468 * when doing so.
1469 *
1470 * Return 1 if we'd lose data, return 0 if the removal is fine,
1471 * and negative values for errors.
1472 */
1473int bad_to_remove_submodule(const char *path, unsigned flags)
1474{
1475        ssize_t len;
1476        struct child_process cp = CHILD_PROCESS_INIT;
1477        struct strbuf buf = STRBUF_INIT;
1478        int ret = 0;
1479
1480        if (!file_exists(path) || is_empty_dir(path))
1481                return 0;
1482
1483        if (!submodule_uses_gitfile(path))
1484                return 1;
1485
1486        argv_array_pushl(&cp.args, "status", "--porcelain",
1487                                   "--ignore-submodules=none", NULL);
1488
1489        if (flags & SUBMODULE_REMOVAL_IGNORE_UNTRACKED)
1490                argv_array_push(&cp.args, "-uno");
1491        else
1492                argv_array_push(&cp.args, "-uall");
1493
1494        if (!(flags & SUBMODULE_REMOVAL_IGNORE_IGNORED_UNTRACKED))
1495                argv_array_push(&cp.args, "--ignored");
1496
1497        prepare_submodule_repo_env(&cp.env_array);
1498        cp.git_cmd = 1;
1499        cp.no_stdin = 1;
1500        cp.out = -1;
1501        cp.dir = path;
1502        if (start_command(&cp)) {
1503                if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1504                        die(_("could not start 'git status' in submodule '%s'"),
1505                                path);
1506                ret = -1;
1507                goto out;
1508        }
1509
1510        len = strbuf_read(&buf, cp.out, 1024);
1511        if (len > 2)
1512                ret = 1;
1513        close(cp.out);
1514
1515        if (finish_command(&cp)) {
1516                if (flags & SUBMODULE_REMOVAL_DIE_ON_ERROR)
1517                        die(_("could not run 'git status' in submodule '%s'"),
1518                                path);
1519                ret = -1;
1520        }
1521out:
1522        strbuf_release(&buf);
1523        return ret;
1524}
1525
1526static const char *get_super_prefix_or_empty(void)
1527{
1528        const char *s = get_super_prefix();
1529        if (!s)
1530                s = "";
1531        return s;
1532}
1533
1534static int submodule_has_dirty_index(const struct submodule *sub)
1535{
1536        struct child_process cp = CHILD_PROCESS_INIT;
1537
1538        prepare_submodule_repo_env(&cp.env_array);
1539
1540        cp.git_cmd = 1;
1541        argv_array_pushl(&cp.args, "diff-index", "--quiet",
1542                                   "--cached", "HEAD", NULL);
1543        cp.no_stdin = 1;
1544        cp.no_stdout = 1;
1545        cp.dir = sub->path;
1546        if (start_command(&cp))
1547                die("could not recurse into submodule '%s'", sub->path);
1548
1549        return finish_command(&cp);
1550}
1551
1552static void submodule_reset_index(const char *path)
1553{
1554        struct child_process cp = CHILD_PROCESS_INIT;
1555        prepare_submodule_repo_env(&cp.env_array);
1556
1557        cp.git_cmd = 1;
1558        cp.no_stdin = 1;
1559        cp.dir = path;
1560
1561        argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1562                                   get_super_prefix_or_empty(), path);
1563        argv_array_pushl(&cp.args, "read-tree", "-u", "--reset", NULL);
1564
1565        argv_array_push(&cp.args, EMPTY_TREE_SHA1_HEX);
1566
1567        if (run_command(&cp))
1568                die("could not reset submodule index");
1569}
1570
1571/**
1572 * Moves a submodule at a given path from a given head to another new head.
1573 * For edge cases (a submodule coming into existence or removing a submodule)
1574 * pass NULL for old or new respectively.
1575 */
1576int submodule_move_head(const char *path,
1577                         const char *old,
1578                         const char *new,
1579                         unsigned flags)
1580{
1581        int ret = 0;
1582        struct child_process cp = CHILD_PROCESS_INIT;
1583        const struct submodule *sub;
1584        int *error_code_ptr, error_code;
1585
1586        if (!is_submodule_active(the_repository, path))
1587                return 0;
1588
1589        if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1590                /*
1591                 * Pass non NULL pointer to is_submodule_populated_gently
1592                 * to prevent die()-ing. We'll use connect_work_tree_and_git_dir
1593                 * to fixup the submodule in the force case later.
1594                 */
1595                error_code_ptr = &error_code;
1596        else
1597                error_code_ptr = NULL;
1598
1599        if (old && !is_submodule_populated_gently(path, error_code_ptr))
1600                return 0;
1601
1602        sub = submodule_from_path(&null_oid, path);
1603
1604        if (!sub)
1605                die("BUG: could not get submodule information for '%s'", path);
1606
1607        if (old && !(flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1608                /* Check if the submodule has a dirty index. */
1609                if (submodule_has_dirty_index(sub))
1610                        return error(_("submodule '%s' has dirty index"), path);
1611        }
1612
1613        if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1614                if (old) {
1615                        if (!submodule_uses_gitfile(path))
1616                                absorb_git_dir_into_superproject("", path,
1617                                        ABSORB_GITDIR_RECURSE_SUBMODULES);
1618                } else {
1619                        char *gitdir = xstrfmt("%s/modules/%s",
1620                                    get_git_common_dir(), sub->name);
1621                        connect_work_tree_and_git_dir(path, gitdir);
1622                        free(gitdir);
1623
1624                        /* make sure the index is clean as well */
1625                        submodule_reset_index(path);
1626                }
1627
1628                if (old && (flags & SUBMODULE_MOVE_HEAD_FORCE)) {
1629                        char *gitdir = xstrfmt("%s/modules/%s",
1630                                    get_git_common_dir(), sub->name);
1631                        connect_work_tree_and_git_dir(path, gitdir);
1632                        free(gitdir);
1633                }
1634        }
1635
1636        prepare_submodule_repo_env(&cp.env_array);
1637
1638        cp.git_cmd = 1;
1639        cp.no_stdin = 1;
1640        cp.dir = path;
1641
1642        argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
1643                        get_super_prefix_or_empty(), path);
1644        argv_array_pushl(&cp.args, "read-tree", "--recurse-submodules", NULL);
1645
1646        if (flags & SUBMODULE_MOVE_HEAD_DRY_RUN)
1647                argv_array_push(&cp.args, "-n");
1648        else
1649                argv_array_push(&cp.args, "-u");
1650
1651        if (flags & SUBMODULE_MOVE_HEAD_FORCE)
1652                argv_array_push(&cp.args, "--reset");
1653        else
1654                argv_array_push(&cp.args, "-m");
1655
1656        argv_array_push(&cp.args, old ? old : EMPTY_TREE_SHA1_HEX);
1657        argv_array_push(&cp.args, new ? new : EMPTY_TREE_SHA1_HEX);
1658
1659        if (run_command(&cp)) {
1660                ret = -1;
1661                goto out;
1662        }
1663
1664        if (!(flags & SUBMODULE_MOVE_HEAD_DRY_RUN)) {
1665                if (new) {
1666                        child_process_init(&cp);
1667                        /* also set the HEAD accordingly */
1668                        cp.git_cmd = 1;
1669                        cp.no_stdin = 1;
1670                        cp.dir = path;
1671
1672                        prepare_submodule_repo_env(&cp.env_array);
1673                        argv_array_pushl(&cp.args, "update-ref", "HEAD", new, NULL);
1674
1675                        if (run_command(&cp)) {
1676                                ret = -1;
1677                                goto out;
1678                        }
1679                } else {
1680                        struct strbuf sb = STRBUF_INIT;
1681
1682                        strbuf_addf(&sb, "%s/.git", path);
1683                        unlink_or_warn(sb.buf);
1684                        strbuf_release(&sb);
1685
1686                        if (is_empty_dir(path))
1687                                rmdir_or_warn(path);
1688                }
1689        }
1690out:
1691        return ret;
1692}
1693
1694static int find_first_merges(struct object_array *result, const char *path,
1695                struct commit *a, struct commit *b)
1696{
1697        int i, j;
1698        struct object_array merges = OBJECT_ARRAY_INIT;
1699        struct commit *commit;
1700        int contains_another;
1701
1702        char merged_revision[42];
1703        const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path",
1704                                   "--all", merged_revision, NULL };
1705        struct rev_info revs;
1706        struct setup_revision_opt rev_opts;
1707
1708        memset(result, 0, sizeof(struct object_array));
1709        memset(&rev_opts, 0, sizeof(rev_opts));
1710
1711        /* get all revisions that merge commit a */
1712        xsnprintf(merged_revision, sizeof(merged_revision), "^%s",
1713                        oid_to_hex(&a->object.oid));
1714        init_revisions(&revs, NULL);
1715        rev_opts.submodule = path;
1716        /* FIXME: can't handle linked worktrees in submodules yet */
1717        revs.single_worktree = path != NULL;
1718        setup_revisions(ARRAY_SIZE(rev_args)-1, rev_args, &revs, &rev_opts);
1719
1720        /* save all revisions from the above list that contain b */
1721        if (prepare_revision_walk(&revs))
1722                die("revision walk setup failed");
1723        while ((commit = get_revision(&revs)) != NULL) {
1724                struct object *o = &(commit->object);
1725                if (in_merge_bases(b, commit))
1726                        add_object_array(o, NULL, &merges);
1727        }
1728        reset_revision_walk();
1729
1730        /* Now we've got all merges that contain a and b. Prune all
1731         * merges that contain another found merge and save them in
1732         * result.
1733         */
1734        for (i = 0; i < merges.nr; i++) {
1735                struct commit *m1 = (struct commit *) merges.objects[i].item;
1736
1737                contains_another = 0;
1738                for (j = 0; j < merges.nr; j++) {
1739                        struct commit *m2 = (struct commit *) merges.objects[j].item;
1740                        if (i != j && in_merge_bases(m2, m1)) {
1741                                contains_another = 1;
1742                                break;
1743                        }
1744                }
1745
1746                if (!contains_another)
1747                        add_object_array(merges.objects[i].item, NULL, result);
1748        }
1749
1750        object_array_clear(&merges);
1751        return result->nr;
1752}
1753
1754static void print_commit(struct commit *commit)
1755{
1756        struct strbuf sb = STRBUF_INIT;
1757        struct pretty_print_context ctx = {0};
1758        ctx.date_mode.type = DATE_NORMAL;
1759        format_commit_message(commit, " %h: %m %s", &sb, &ctx);
1760        fprintf(stderr, "%s\n", sb.buf);
1761        strbuf_release(&sb);
1762}
1763
1764#define MERGE_WARNING(path, msg) \
1765        warning("Failed to merge submodule %s (%s)", path, msg);
1766
1767int merge_submodule(struct object_id *result, const char *path,
1768                    const struct object_id *base, const struct object_id *a,
1769                    const struct object_id *b, int search)
1770{
1771        struct commit *commit_base, *commit_a, *commit_b;
1772        int parent_count;
1773        struct object_array merges;
1774
1775        int i;
1776
1777        /* store a in result in case we fail */
1778        oidcpy(result, a);
1779
1780        /* we can not handle deletion conflicts */
1781        if (is_null_oid(base))
1782                return 0;
1783        if (is_null_oid(a))
1784                return 0;
1785        if (is_null_oid(b))
1786                return 0;
1787
1788        if (add_submodule_odb(path)) {
1789                MERGE_WARNING(path, "not checked out");
1790                return 0;
1791        }
1792
1793        if (!(commit_base = lookup_commit_reference(base)) ||
1794            !(commit_a = lookup_commit_reference(a)) ||
1795            !(commit_b = lookup_commit_reference(b))) {
1796                MERGE_WARNING(path, "commits not present");
1797                return 0;
1798        }
1799
1800        /* check whether both changes are forward */
1801        if (!in_merge_bases(commit_base, commit_a) ||
1802            !in_merge_bases(commit_base, commit_b)) {
1803                MERGE_WARNING(path, "commits don't follow merge-base");
1804                return 0;
1805        }
1806
1807        /* Case #1: a is contained in b or vice versa */
1808        if (in_merge_bases(commit_a, commit_b)) {
1809                oidcpy(result, b);
1810                return 1;
1811        }
1812        if (in_merge_bases(commit_b, commit_a)) {
1813                oidcpy(result, a);
1814                return 1;
1815        }
1816
1817        /*
1818         * Case #2: There are one or more merges that contain a and b in
1819         * the submodule. If there is only one, then present it as a
1820         * suggestion to the user, but leave it marked unmerged so the
1821         * user needs to confirm the resolution.
1822         */
1823
1824        /* Skip the search if makes no sense to the calling context.  */
1825        if (!search)
1826                return 0;
1827
1828        /* find commit which merges them */
1829        parent_count = find_first_merges(&merges, path, commit_a, commit_b);
1830        switch (parent_count) {
1831        case 0:
1832                MERGE_WARNING(path, "merge following commits not found");
1833                break;
1834
1835        case 1:
1836                MERGE_WARNING(path, "not fast-forward");
1837                fprintf(stderr, "Found a possible merge resolution "
1838                                "for the submodule:\n");
1839                print_commit((struct commit *) merges.objects[0].item);
1840                fprintf(stderr,
1841                        "If this is correct simply add it to the index "
1842                        "for example\n"
1843                        "by using:\n\n"
1844                        "  git update-index --cacheinfo 160000 %s \"%s\"\n\n"
1845                        "which will accept this suggestion.\n",
1846                        oid_to_hex(&merges.objects[0].item->oid), path);
1847                break;
1848
1849        default:
1850                MERGE_WARNING(path, "multiple merges found");
1851                for (i = 0; i < merges.nr; i++)
1852                        print_commit((struct commit *) merges.objects[i].item);
1853        }
1854
1855        object_array_clear(&merges);
1856        return 0;
1857}
1858
1859/*
1860 * Embeds a single submodules git directory into the superprojects git dir,
1861 * non recursively.
1862 */
1863static void relocate_single_git_dir_into_superproject(const char *prefix,
1864                                                      const char *path)
1865{
1866        char *old_git_dir = NULL, *real_old_git_dir = NULL, *real_new_git_dir = NULL;
1867        const char *new_git_dir;
1868        const struct submodule *sub;
1869
1870        if (submodule_uses_worktrees(path))
1871                die(_("relocate_gitdir for submodule '%s' with "
1872                      "more than one worktree not supported"), path);
1873
1874        old_git_dir = xstrfmt("%s/.git", path);
1875        if (read_gitfile(old_git_dir))
1876                /* If it is an actual gitfile, it doesn't need migration. */
1877                return;
1878
1879        real_old_git_dir = real_pathdup(old_git_dir, 1);
1880
1881        sub = submodule_from_path(&null_oid, path);
1882        if (!sub)
1883                die(_("could not lookup name for submodule '%s'"), path);
1884
1885        new_git_dir = git_path("modules/%s", sub->name);
1886        if (safe_create_leading_directories_const(new_git_dir) < 0)
1887                die(_("could not create directory '%s'"), new_git_dir);
1888        real_new_git_dir = real_pathdup(new_git_dir, 1);
1889
1890        fprintf(stderr, _("Migrating git directory of '%s%s' from\n'%s' to\n'%s'\n"),
1891                get_super_prefix_or_empty(), path,
1892                real_old_git_dir, real_new_git_dir);
1893
1894        relocate_gitdir(path, real_old_git_dir, real_new_git_dir);
1895
1896        free(old_git_dir);
1897        free(real_old_git_dir);
1898        free(real_new_git_dir);
1899}
1900
1901/*
1902 * Migrate the git directory of the submodule given by path from
1903 * having its git directory within the working tree to the git dir nested
1904 * in its superprojects git dir under modules/.
1905 */
1906void absorb_git_dir_into_superproject(const char *prefix,
1907                                      const char *path,
1908                                      unsigned flags)
1909{
1910        int err_code;
1911        const char *sub_git_dir;
1912        struct strbuf gitdir = STRBUF_INIT;
1913        strbuf_addf(&gitdir, "%s/.git", path);
1914        sub_git_dir = resolve_gitdir_gently(gitdir.buf, &err_code);
1915
1916        /* Not populated? */
1917        if (!sub_git_dir) {
1918                const struct submodule *sub;
1919
1920                if (err_code == READ_GITFILE_ERR_STAT_FAILED) {
1921                        /* unpopulated as expected */
1922                        strbuf_release(&gitdir);
1923                        return;
1924                }
1925
1926                if (err_code != READ_GITFILE_ERR_NOT_A_REPO)
1927                        /* We don't know what broke here. */
1928                        read_gitfile_error_die(err_code, path, NULL);
1929
1930                /*
1931                * Maybe populated, but no git directory was found?
1932                * This can happen if the superproject is a submodule
1933                * itself and was just absorbed. The absorption of the
1934                * superproject did not rewrite the git file links yet,
1935                * fix it now.
1936                */
1937                sub = submodule_from_path(&null_oid, path);
1938                if (!sub)
1939                        die(_("could not lookup name for submodule '%s'"), path);
1940                connect_work_tree_and_git_dir(path,
1941                        git_path("modules/%s", sub->name));
1942        } else {
1943                /* Is it already absorbed into the superprojects git dir? */
1944                char *real_sub_git_dir = real_pathdup(sub_git_dir, 1);
1945                char *real_common_git_dir = real_pathdup(get_git_common_dir(), 1);
1946
1947                if (!starts_with(real_sub_git_dir, real_common_git_dir))
1948                        relocate_single_git_dir_into_superproject(prefix, path);
1949
1950                free(real_sub_git_dir);
1951                free(real_common_git_dir);
1952        }
1953        strbuf_release(&gitdir);
1954
1955        if (flags & ABSORB_GITDIR_RECURSE_SUBMODULES) {
1956                struct child_process cp = CHILD_PROCESS_INIT;
1957                struct strbuf sb = STRBUF_INIT;
1958
1959                if (flags & ~ABSORB_GITDIR_RECURSE_SUBMODULES)
1960                        die("BUG: we don't know how to pass the flags down?");
1961
1962                strbuf_addstr(&sb, get_super_prefix_or_empty());
1963                strbuf_addstr(&sb, path);
1964                strbuf_addch(&sb, '/');
1965
1966                cp.dir = path;
1967                cp.git_cmd = 1;
1968                cp.no_stdin = 1;
1969                argv_array_pushl(&cp.args, "--super-prefix", sb.buf,
1970                                           "submodule--helper",
1971                                           "absorb-git-dirs", NULL);
1972                prepare_submodule_repo_env(&cp.env_array);
1973                if (run_command(&cp))
1974                        die(_("could not recurse into submodule '%s'"), path);
1975
1976                strbuf_release(&sb);
1977        }
1978}
1979
1980const char *get_superproject_working_tree(void)
1981{
1982        struct child_process cp = CHILD_PROCESS_INIT;
1983        struct strbuf sb = STRBUF_INIT;
1984        const char *one_up = real_path_if_valid("../");
1985        const char *cwd = xgetcwd();
1986        const char *ret = NULL;
1987        const char *subpath;
1988        int code;
1989        ssize_t len;
1990
1991        if (!is_inside_work_tree())
1992                /*
1993                 * FIXME:
1994                 * We might have a superproject, but it is harder
1995                 * to determine.
1996                 */
1997                return NULL;
1998
1999        if (!one_up)
2000                return NULL;
2001
2002        subpath = relative_path(cwd, one_up, &sb);
2003
2004        prepare_submodule_repo_env(&cp.env_array);
2005        argv_array_pop(&cp.env_array);
2006
2007        argv_array_pushl(&cp.args, "--literal-pathspecs", "-C", "..",
2008                        "ls-files", "-z", "--stage", "--full-name", "--",
2009                        subpath, NULL);
2010        strbuf_reset(&sb);
2011
2012        cp.no_stdin = 1;
2013        cp.no_stderr = 1;
2014        cp.out = -1;
2015        cp.git_cmd = 1;
2016
2017        if (start_command(&cp))
2018                die(_("could not start ls-files in .."));
2019
2020        len = strbuf_read(&sb, cp.out, PATH_MAX);
2021        close(cp.out);
2022
2023        if (starts_with(sb.buf, "160000")) {
2024                int super_sub_len;
2025                int cwd_len = strlen(cwd);
2026                char *super_sub, *super_wt;
2027
2028                /*
2029                 * There is a superproject having this repo as a submodule.
2030                 * The format is <mode> SP <hash> SP <stage> TAB <full name> \0,
2031                 * We're only interested in the name after the tab.
2032                 */
2033                super_sub = strchr(sb.buf, '\t') + 1;
2034                super_sub_len = sb.buf + sb.len - super_sub - 1;
2035
2036                if (super_sub_len > cwd_len ||
2037                    strcmp(&cwd[cwd_len - super_sub_len], super_sub))
2038                        die (_("BUG: returned path string doesn't match cwd?"));
2039
2040                super_wt = xstrdup(cwd);
2041                super_wt[cwd_len - super_sub_len] = '\0';
2042
2043                ret = real_path(super_wt);
2044                free(super_wt);
2045        }
2046        strbuf_release(&sb);
2047
2048        code = finish_command(&cp);
2049
2050        if (code == 128)
2051                /* '../' is not a git repository */
2052                return NULL;
2053        if (code == 0 && len == 0)
2054                /* There is an unrelated git repository at '../' */
2055                return NULL;
2056        if (code)
2057                die(_("ls-tree returned unexpected return code %d"), code);
2058
2059        return ret;
2060}
2061
2062/*
2063 * Put the gitdir for a submodule (given relative to the main
2064 * repository worktree) into `buf`, or return -1 on error.
2065 */
2066int submodule_to_gitdir(struct strbuf *buf, const char *submodule)
2067{
2068        const struct submodule *sub;
2069        const char *git_dir;
2070        int ret = 0;
2071
2072        strbuf_reset(buf);
2073        strbuf_addstr(buf, submodule);
2074        strbuf_complete(buf, '/');
2075        strbuf_addstr(buf, ".git");
2076
2077        git_dir = read_gitfile(buf->buf);
2078        if (git_dir) {
2079                strbuf_reset(buf);
2080                strbuf_addstr(buf, git_dir);
2081        }
2082        if (!is_git_directory(buf->buf)) {
2083                sub = submodule_from_path(&null_oid, submodule);
2084                if (!sub) {
2085                        ret = -1;
2086                        goto cleanup;
2087                }
2088                strbuf_reset(buf);
2089                strbuf_git_path(buf, "%s/%s", "modules", sub->name);
2090        }
2091
2092cleanup:
2093        return ret;
2094}