git.oblomov.eu Git - git/blob - submodule.c

   1 #include "cache.h"
   2 #include "submodule.h"
   3 #include "dir.h"
   4 #include "diff.h"
   5 #include "commit.h"
   6 #include "revision.h"
   7 #include "run-command.h"
   8 #include "diffcore.h"
   9 #include "refs.h"
  10 #include "string-list.h"
  11 #include "sha1-array.h"
  12 #include "argv-array.h"
  13 #include "blob.h"
  14
  15 static struct string_list config_name_for_path;
  16 static struct string_list config_fetch_recurse_submodules_for_name;
  17 static struct string_list config_ignore_for_name;
  18 static int config_fetch_recurse_submodules = RECURSE_SUBMODULES_ON_DEMAND;
  19 static struct string_list changed_submodule_paths;
  20 static int initialized_fetch_ref_tips;
  21 static struct sha1_array ref_tips_before_fetch;
  22 static struct sha1_array ref_tips_after_fetch;
  23
  24 /*
  25  * The following flag is set if the .gitmodules file is unmerged. We then
  26  * disable recursion for all submodules where .git/config doesn't have a
  27  * matching config entry because we can't guess what might be configured in
  28  * .gitmodules unless the user resolves the conflict. When a command line
  29  * option is given (which always overrides configuration) this flag will be
  30  * ignored.
  31  */
  32 static int gitmodules_is_unmerged;
  33
  34 /*
  35  * This flag is set if the .gitmodules file had unstaged modifications on
  36  * startup. This must be checked before allowing modifications to the
  37  * .gitmodules file with the intention to stage them later, because when
  38  * continuing we would stage the modifications the user didn't stage herself
  39  * too. That might change in a future version when we learn to stage the
  40  * changes we do ourselves without staging any previous modifications.
  41  */
  42 static int gitmodules_is_modified;
  43
  44
  45 int is_staging_gitmodules_ok(void)
  46 {
  47         return !gitmodules_is_modified;
  48 }
  49
  50 /*
  51  * Try to update the "path" entry in the "submodule.<name>" section of the
  52  * .gitmodules file. Return 0 only if a .gitmodules file was found, a section
  53  * with the correct path=<oldpath> setting was found and we could update it.
  54  */
  55 int update_path_in_gitmodules(const char *oldpath, const char *newpath)
  56 {
  57         struct strbuf entry = STRBUF_INIT;
  58         struct string_list_item *path_option;
  59
  60         if (!file_exists(".gitmodules")) /* Do nothing without .gitmodules */
  61                 return -1;
  62
  63         if (gitmodules_is_unmerged)
  64                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
  65
  66         path_option = unsorted_string_list_lookup(&config_name_for_path, oldpath);
  67         if (!path_option) {
  68                 warning(_("Could not find section in .gitmodules where path=%s"), oldpath);
  69                 return -1;
  70         }
  71         strbuf_addstr(&entry, "submodule.");
  72         strbuf_addstr(&entry, path_option->util);
  73         strbuf_addstr(&entry, ".path");
  74         if (git_config_set_in_file(".gitmodules", entry.buf, newpath) < 0) {
  75                 /* Maybe the user already did that, don't error out here */
  76                 warning(_("Could not update .gitmodules entry %s"), entry.buf);
  77                 strbuf_release(&entry);
  78                 return -1;
  79         }
  80         strbuf_release(&entry);
  81         return 0;
  82 }
  83
  84 /*
  85  * Try to remove the "submodule.<name>" section from .gitmodules where the given
  86  * path is configured. Return 0 only if a .gitmodules file was found, a section
  87  * with the correct path=<path> setting was found and we could remove it.
  88  */
  89 int remove_path_from_gitmodules(const char *path)
  90 {
  91         struct strbuf sect = STRBUF_INIT;
  92         struct string_list_item *path_option;
  93
  94         if (!file_exists(".gitmodules")) /* Do nothing without .gitmodules */
  95                 return -1;
  96
  97         if (gitmodules_is_unmerged)
  98                 die(_("Cannot change unmerged .gitmodules, resolve merge conflicts first"));
  99
 100         path_option = unsorted_string_list_lookup(&config_name_for_path, path);
 101         if (!path_option) {
 102                 warning(_("Could not find section in .gitmodules where path=%s"), path);
 103                 return -1;
 104         }
 105         strbuf_addstr(&sect, "submodule.");
 106         strbuf_addstr(&sect, path_option->util);
 107         if (git_config_rename_section_in_file(".gitmodules", sect.buf, NULL) < 0) {
 108                 /* Maybe the user already did that, don't error out here */
 109                 warning(_("Could not remove .gitmodules entry for %s"), path);
 110                 strbuf_release(&sect);
 111                 return -1;
 112         }
 113         strbuf_release(&sect);
 114         return 0;
 115 }
 116
 117 void stage_updated_gitmodules(void)
 118 {
 119         struct strbuf buf = STRBUF_INIT;
 120         struct stat st;
 121         int pos;
 122         struct cache_entry *ce;
 123         int namelen = strlen(".gitmodules");
 124
 125         pos = cache_name_pos(".gitmodules", namelen);
 126         if (pos < 0) {
 127                 warning(_("could not find .gitmodules in index"));
 128                 return;
 129         }
 130         ce = active_cache[pos];
 131         ce->ce_flags = namelen;
 132         if (strbuf_read_file(&buf, ".gitmodules", 0) < 0)
 133                 die(_("reading updated .gitmodules failed"));
 134         if (lstat(".gitmodules", &st) < 0)
 135                 die_errno(_("unable to stat updated .gitmodules"));
 136         fill_stat_cache_info(ce, &st);
 137         ce->ce_mode = ce_mode_from_stat(ce, st.st_mode);
 138         if (remove_cache_entry_at(pos) < 0)
 139                 die(_("unable to remove .gitmodules from index"));
 140         if (write_sha1_file(buf.buf, buf.len, blob_type, ce->sha1))
 141                 die(_("adding updated .gitmodules failed"));
 142         if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE))
 143                 die(_("staging updated .gitmodules failed"));
 144 }
 145
 146 static int add_submodule_odb(const char *path)
 147 {
 148         struct strbuf objects_directory = STRBUF_INIT;
 149         struct alternate_object_database *alt_odb;
 150         int ret = 0;
 151         const char *git_dir;
 152
 153         strbuf_addf(&objects_directory, "%s/.git", path);
 154         git_dir = read_gitfile(objects_directory.buf);
 155         if (git_dir) {
 156                 strbuf_reset(&objects_directory);
 157                 strbuf_addstr(&objects_directory, git_dir);
 158         }
 159         strbuf_addstr(&objects_directory, "/objects/");
 160         if (!is_directory(objects_directory.buf)) {
 161                 ret = -1;
 162                 goto done;
 163         }
 164         /* avoid adding it twice */
 165         for (alt_odb = alt_odb_list; alt_odb; alt_odb = alt_odb->next)
 166                 if (alt_odb->name - alt_odb->base == objects_directory.len &&
 167                                 !strncmp(alt_odb->base, objects_directory.buf,
 168                                         objects_directory.len))
 169                         goto done;
 170
 171         alt_odb = xmalloc(objects_directory.len + 42 + sizeof(*alt_odb));
 172         alt_odb->next = alt_odb_list;
 173         strcpy(alt_odb->base, objects_directory.buf);
 174         alt_odb->name = alt_odb->base + objects_directory.len;
 175         alt_odb->name[2] = '/';
 176         alt_odb->name[40] = '\0';
 177         alt_odb->name[41] = '\0';
 178         alt_odb_list = alt_odb;
 179
 180         /* add possible alternates from the submodule */
 181         read_info_alternates(objects_directory.buf, 0);
 182         prepare_alt_odb();
 183 done:
 184         strbuf_release(&objects_directory);
 185         return ret;
 186 }
 187
 188 void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
 189                                              const char *path)
 190 {
 191         struct string_list_item *path_option, *ignore_option;
 192         path_option = unsorted_string_list_lookup(&config_name_for_path, path);
 193         if (path_option) {
 194                 ignore_option = unsorted_string_list_lookup(&config_ignore_for_name, path_option->util);
 195                 if (ignore_option)
 196                         handle_ignore_submodules_arg(diffopt, ignore_option->util);
 197                 else if (gitmodules_is_unmerged)
 198                         DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
 199         }
 200 }
 201
 202 int submodule_config(const char *var, const char *value, void *cb)
 203 {
 204         if (!prefixcmp(var, "submodule."))
 205                 return parse_submodule_config_option(var, value);
 206         else if (!strcmp(var, "fetch.recursesubmodules")) {
 207                 config_fetch_recurse_submodules = parse_fetch_recurse_submodules_arg(var, value);
 208                 return 0;
 209         }
 210         return 0;
 211 }
 212
 213 void gitmodules_config(void)
 214 {
 215         const char *work_tree = get_git_work_tree();
 216         if (work_tree) {
 217                 struct strbuf gitmodules_path = STRBUF_INIT;
 218                 int pos;
 219                 strbuf_addstr(&gitmodules_path, work_tree);
 220                 strbuf_addstr(&gitmodules_path, "/.gitmodules");
 221                 if (read_cache() < 0)
 222                         die("index file corrupt");
 223                 pos = cache_name_pos(".gitmodules", 11);
 224                 if (pos < 0) { /* .gitmodules not found or isn't merged */
 225                         pos = -1 - pos;
 226                         if (active_nr > pos) {  /* there is a .gitmodules */
 227                                 const struct cache_entry *ce = active_cache[pos];
 228                                 if (ce_namelen(ce) == 11 &&
 229                                     !memcmp(ce->name, ".gitmodules", 11))
 230                                         gitmodules_is_unmerged = 1;
 231                         }
 232                 } else if (pos < active_nr) {
 233                         struct stat st;
 234                         if (lstat(".gitmodules", &st) == 0 &&
 235                             ce_match_stat(active_cache[pos], &st, 0) & DATA_CHANGED)
 236                                 gitmodules_is_modified = 1;
 237                 }
 238
 239                 if (!gitmodules_is_unmerged)
 240                         git_config_from_file(submodule_config, gitmodules_path.buf, NULL);
 241                 strbuf_release(&gitmodules_path);
 242         }
 243 }
 244
 245 int parse_submodule_config_option(const char *var, const char *value)
 246 {
 247         struct string_list_item *config;
 248         const char *name, *key;
 249         int namelen;
 250
 251         if (parse_config_key(var, "submodule", &name, &namelen, &key) < 0 || !name)
 252                 return 0;
 253
 254         if (!strcmp(key, "path")) {
 255                 if (!value)
 256                         return config_error_nonbool(var);
 257
 258                 config = unsorted_string_list_lookup(&config_name_for_path, value);
 259                 if (config)
 260                         free(config->util);
 261                 else
 262                         config = string_list_append(&config_name_for_path, xstrdup(value));
 263                 config->util = xmemdupz(name, namelen);
 264         } else if (!strcmp(key, "fetchrecursesubmodules")) {
 265                 char *name_cstr = xmemdupz(name, namelen);
 266                 config = unsorted_string_list_lookup(&config_fetch_recurse_submodules_for_name, name_cstr);
 267                 if (!config)
 268                         config = string_list_append(&config_fetch_recurse_submodules_for_name, name_cstr);
 269                 else
 270                         free(name_cstr);
 271                 config->util = (void *)(intptr_t)parse_fetch_recurse_submodules_arg(var, value);
 272         } else if (!strcmp(key, "ignore")) {
 273                 char *name_cstr;
 274
 275                 if (!value)
 276                         return config_error_nonbool(var);
 277
 278                 if (strcmp(value, "untracked") && strcmp(value, "dirty") &&
 279                     strcmp(value, "all") && strcmp(value, "none")) {
 280                         warning("Invalid parameter \"%s\" for config option \"submodule.%s.ignore\"", value, var);
 281                         return 0;
 282                 }
 283
 284                 name_cstr = xmemdupz(name, namelen);
 285                 config = unsorted_string_list_lookup(&config_ignore_for_name, name_cstr);
 286                 if (config) {
 287                         free(config->util);
 288                         free(name_cstr);
 289                 } else
 290                         config = string_list_append(&config_ignore_for_name, name_cstr);
 291                 config->util = xstrdup(value);
 292                 return 0;
 293         }
 294         return 0;
 295 }
 296
 297 void handle_ignore_submodules_arg(struct diff_options *diffopt,
 298                                   const char *arg)
 299 {
 300         DIFF_OPT_CLR(diffopt, IGNORE_SUBMODULES);
 301         DIFF_OPT_CLR(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
 302         DIFF_OPT_CLR(diffopt, IGNORE_DIRTY_SUBMODULES);
 303
 304         if (!strcmp(arg, "all"))
 305                 DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
 306         else if (!strcmp(arg, "untracked"))
 307                 DIFF_OPT_SET(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
 308         else if (!strcmp(arg, "dirty"))
 309                 DIFF_OPT_SET(diffopt, IGNORE_DIRTY_SUBMODULES);
 310         else if (strcmp(arg, "none"))
 311                 die("bad --ignore-submodules argument: %s", arg);
 312 }
 313
 314 static int prepare_submodule_summary(struct rev_info *rev, const char *path,
 315                 struct commit *left, struct commit *right,
 316                 int *fast_forward, int *fast_backward)
 317 {
 318         struct commit_list *merge_bases, *list;
 319
 320         init_revisions(rev, NULL);
 321         setup_revisions(0, NULL, rev, NULL);
 322         rev->left_right = 1;
 323         rev->first_parent_only = 1;
 324         left->object.flags |= SYMMETRIC_LEFT;
 325         add_pending_object(rev, &left->object, path);
 326         add_pending_object(rev, &right->object, path);
 327         merge_bases = get_merge_bases(left, right, 1);
 328         if (merge_bases) {
 329                 if (merge_bases->item == left)
 330                         *fast_forward = 1;
 331                 else if (merge_bases->item == right)
 332                         *fast_backward = 1;
 333         }
 334         for (list = merge_bases; list; list = list->next) {
 335                 list->item->object.flags |= UNINTERESTING;
 336                 add_pending_object(rev, &list->item->object,
 337                         sha1_to_hex(list->item->object.sha1));
 338         }
 339         return prepare_revision_walk(rev);
 340 }
 341
 342 static void print_submodule_summary(struct rev_info *rev, FILE *f,
 343                 const char *line_prefix,
 344                 const char *del, const char *add, const char *reset)
 345 {
 346         static const char format[] = "  %m %s";
 347         struct strbuf sb = STRBUF_INIT;
 348         struct commit *commit;
 349
 350         while ((commit = get_revision(rev))) {
 351                 struct pretty_print_context ctx = {0};
 352                 ctx.date_mode = rev->date_mode;
 353                 ctx.output_encoding = get_log_output_encoding();
 354                 strbuf_setlen(&sb, 0);
 355                 strbuf_addstr(&sb, line_prefix);
 356                 if (commit->object.flags & SYMMETRIC_LEFT) {
 357                         if (del)
 358                                 strbuf_addstr(&sb, del);
 359                 }
 360                 else if (add)
 361                         strbuf_addstr(&sb, add);
 362                 format_commit_message(commit, format, &sb, &ctx);
 363                 if (reset)
 364                         strbuf_addstr(&sb, reset);
 365                 strbuf_addch(&sb, '\n');
 366                 fprintf(f, "%s", sb.buf);
 367         }
 368         strbuf_release(&sb);
 369 }
 370
 371 int parse_fetch_recurse_submodules_arg(const char *opt, const char *arg)
 372 {
 373         switch (git_config_maybe_bool(opt, arg)) {
 374         case 1:
 375                 return RECURSE_SUBMODULES_ON;
 376         case 0:
 377                 return RECURSE_SUBMODULES_OFF;
 378         default:
 379                 if (!strcmp(arg, "on-demand"))
 380                         return RECURSE_SUBMODULES_ON_DEMAND;
 381                 die("bad %s argument: %s", opt, arg);
 382         }
 383 }
 384
 385 void show_submodule_summary(FILE *f, const char *path,
 386                 const char *line_prefix,
 387                 unsigned char one[20], unsigned char two[20],
 388                 unsigned dirty_submodule, const char *meta,
 389                 const char *del, const char *add, const char *reset)
 390 {
 391         struct rev_info rev;
 392         struct commit *left = NULL, *right = NULL;
 393         const char *message = NULL;
 394         struct strbuf sb = STRBUF_INIT;
 395         int fast_forward = 0, fast_backward = 0;
 396
 397         if (is_null_sha1(two))
 398                 message = "(submodule deleted)";
 399         else if (add_submodule_odb(path))
 400                 message = "(not checked out)";
 401         else if (is_null_sha1(one))
 402                 message = "(new submodule)";
 403         else if (!(left = lookup_commit_reference(one)) ||
 404                  !(right = lookup_commit_reference(two)))
 405                 message = "(commits not present)";
 406         else if (prepare_submodule_summary(&rev, path, left, right,
 407                                            &fast_forward, &fast_backward))
 408                 message = "(revision walker failed)";
 409
 410         if (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED)
 411                 fprintf(f, "%sSubmodule %s contains untracked content\n",
 412                         line_prefix, path);
 413         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
 414                 fprintf(f, "%sSubmodule %s contains modified content\n",
 415                         line_prefix, path);
 416
 417         if (!hashcmp(one, two)) {
 418                 strbuf_release(&sb);
 419                 return;
 420         }
 421
 422         strbuf_addf(&sb, "%s%sSubmodule %s %s..", line_prefix, meta, path,
 423                         find_unique_abbrev(one, DEFAULT_ABBREV));
 424         if (!fast_backward && !fast_forward)
 425                 strbuf_addch(&sb, '.');
 426         strbuf_addf(&sb, "%s", find_unique_abbrev(two, DEFAULT_ABBREV));
 427         if (message)
 428                 strbuf_addf(&sb, " %s%s\n", message, reset);
 429         else
 430                 strbuf_addf(&sb, "%s:%s\n", fast_backward ? " (rewind)" : "", reset);
 431         fwrite(sb.buf, sb.len, 1, f);
 432
 433         if (!message) /* only NULL if we succeeded in setting up the walk */
 434                 print_submodule_summary(&rev, f, line_prefix, del, add, reset);
 435         if (left)
 436                 clear_commit_marks(left, ~0);
 437         if (right)
 438                 clear_commit_marks(right, ~0);
 439
 440         strbuf_release(&sb);
 441 }
 442
 443 void set_config_fetch_recurse_submodules(int value)
 444 {
 445         config_fetch_recurse_submodules = value;
 446 }
 447
 448 static int has_remote(const char *refname, const unsigned char *sha1, int flags, void *cb_data)
 449 {
 450         return 1;
 451 }
 452
 453 static int submodule_needs_pushing(const char *path, const unsigned char sha1[20])
 454 {
 455         if (add_submodule_odb(path) || !lookup_commit_reference(sha1))
 456                 return 0;
 457
 458         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 459                 struct child_process cp;
 460                 const char *argv[] = {"rev-list", NULL, "--not", "--remotes", "-n", "1" , NULL};
 461                 struct strbuf buf = STRBUF_INIT;
 462                 int needs_pushing = 0;
 463
 464                 argv[1] = sha1_to_hex(sha1);
 465                 memset(&cp, 0, sizeof(cp));
 466                 cp.argv = argv;
 467                 cp.env = local_repo_env;
 468                 cp.git_cmd = 1;
 469                 cp.no_stdin = 1;
 470                 cp.out = -1;
 471                 cp.dir = path;
 472                 if (start_command(&cp))
 473                         die("Could not run 'git rev-list %s --not --remotes -n 1' command in submodule %s",
 474                                 sha1_to_hex(sha1), path);
 475                 if (strbuf_read(&buf, cp.out, 41))
 476                         needs_pushing = 1;
 477                 finish_command(&cp);
 478                 close(cp.out);
 479                 strbuf_release(&buf);
 480                 return needs_pushing;
 481         }
 482
 483         return 0;
 484 }
 485
 486 static void collect_submodules_from_diff(struct diff_queue_struct *q,
 487                                          struct diff_options *options,
 488                                          void *data)
 489 {
 490         int i;
 491         struct string_list *needs_pushing = data;
 492
 493         for (i = 0; i < q->nr; i++) {
 494                 struct diff_filepair *p = q->queue[i];
 495                 if (!S_ISGITLINK(p->two->mode))
 496                         continue;
 497                 if (submodule_needs_pushing(p->two->path, p->two->sha1))
 498                         string_list_insert(needs_pushing, p->two->path);
 499         }
 500 }
 501
 502 static void find_unpushed_submodule_commits(struct commit *commit,
 503                 struct string_list *needs_pushing)
 504 {
 505         struct rev_info rev;
 506
 507         init_revisions(&rev, NULL);
 508         rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 509         rev.diffopt.format_callback = collect_submodules_from_diff;
 510         rev.diffopt.format_callback_data = needs_pushing;
 511         diff_tree_combined_merge(commit, 1, &rev);
 512 }
 513
 514 int find_unpushed_submodules(unsigned char new_sha1[20],
 515                 const char *remotes_name, struct string_list *needs_pushing)
 516 {
 517         struct rev_info rev;
 518         struct commit *commit;
 519         const char *argv[] = {NULL, NULL, "--not", "NULL", NULL};
 520         int argc = ARRAY_SIZE(argv) - 1;
 521         char *sha1_copy;
 522
 523         struct strbuf remotes_arg = STRBUF_INIT;
 524
 525         strbuf_addf(&remotes_arg, "--remotes=%s", remotes_name);
 526         init_revisions(&rev, NULL);
 527         sha1_copy = xstrdup(sha1_to_hex(new_sha1));
 528         argv[1] = sha1_copy;
 529         argv[3] = remotes_arg.buf;
 530         setup_revisions(argc, argv, &rev, NULL);
 531         if (prepare_revision_walk(&rev))
 532                 die("revision walk setup failed");
 533
 534         while ((commit = get_revision(&rev)) != NULL)
 535                 find_unpushed_submodule_commits(commit, needs_pushing);
 536
 537         reset_revision_walk();
 538         free(sha1_copy);
 539         strbuf_release(&remotes_arg);
 540
 541         return needs_pushing->nr;
 542 }
 543
 544 static int push_submodule(const char *path)
 545 {
 546         if (add_submodule_odb(path))
 547                 return 1;
 548
 549         if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 550                 struct child_process cp;
 551                 const char *argv[] = {"push", NULL};
 552
 553                 memset(&cp, 0, sizeof(cp));
 554                 cp.argv = argv;
 555                 cp.env = local_repo_env;
 556                 cp.git_cmd = 1;
 557                 cp.no_stdin = 1;
 558                 cp.dir = path;
 559                 if (run_command(&cp))
 560                         return 0;
 561                 close(cp.out);
 562         }
 563
 564         return 1;
 565 }
 566
 567 int push_unpushed_submodules(unsigned char new_sha1[20], const char *remotes_name)
 568 {
 569         int i, ret = 1;
 570         struct string_list needs_pushing;
 571
 572         memset(&needs_pushing, 0, sizeof(struct string_list));
 573         needs_pushing.strdup_strings = 1;
 574
 575         if (!find_unpushed_submodules(new_sha1, remotes_name, &needs_pushing))
 576                 return 1;
 577
 578         for (i = 0; i < needs_pushing.nr; i++) {
 579                 const char *path = needs_pushing.items[i].string;
 580                 fprintf(stderr, "Pushing submodule '%s'\n", path);
 581                 if (!push_submodule(path)) {
 582                         fprintf(stderr, "Unable to push submodule '%s'\n", path);
 583                         ret = 0;
 584                 }
 585         }
 586
 587         string_list_clear(&needs_pushing, 0);
 588
 589         return ret;
 590 }
 591
 592 static int is_submodule_commit_present(const char *path, unsigned char sha1[20])
 593 {
 594         int is_present = 0;
 595         if (!add_submodule_odb(path) && lookup_commit_reference(sha1)) {
 596                 /* Even if the submodule is checked out and the commit is
 597                  * present, make sure it is reachable from a ref. */
 598                 struct child_process cp;
 599                 const char *argv[] = {"rev-list", "-n", "1", NULL, "--not", "--all", NULL};
 600                 struct strbuf buf = STRBUF_INIT;
 601
 602                 argv[3] = sha1_to_hex(sha1);
 603                 memset(&cp, 0, sizeof(cp));
 604                 cp.argv = argv;
 605                 cp.env = local_repo_env;
 606                 cp.git_cmd = 1;
 607                 cp.no_stdin = 1;
 608                 cp.out = -1;
 609                 cp.dir = path;
 610                 if (!run_command(&cp) && !strbuf_read(&buf, cp.out, 1024))
 611                         is_present = 1;
 612
 613                 close(cp.out);
 614                 strbuf_release(&buf);
 615         }
 616         return is_present;
 617 }
 618
 619 static void submodule_collect_changed_cb(struct diff_queue_struct *q,
 620                                          struct diff_options *options,
 621                                          void *data)
 622 {
 623         int i;
 624         for (i = 0; i < q->nr; i++) {
 625                 struct diff_filepair *p = q->queue[i];
 626                 if (!S_ISGITLINK(p->two->mode))
 627                         continue;
 628
 629                 if (S_ISGITLINK(p->one->mode)) {
 630                         /* NEEDSWORK: We should honor the name configured in
 631                          * the .gitmodules file of the commit we are examining
 632                          * here to be able to correctly follow submodules
 633                          * being moved around. */
 634                         struct string_list_item *path;
 635                         path = unsorted_string_list_lookup(&changed_submodule_paths, p->two->path);
 636                         if (!path && !is_submodule_commit_present(p->two->path, p->two->sha1))
 637                                 string_list_append(&changed_submodule_paths, xstrdup(p->two->path));
 638                 } else {
 639                         /* Submodule is new or was moved here */
 640                         /* NEEDSWORK: When the .git directories of submodules
 641                          * live inside the superprojects .git directory some
 642                          * day we should fetch new submodules directly into
 643                          * that location too when config or options request
 644                          * that so they can be checked out from there. */
 645                         continue;
 646                 }
 647         }
 648 }
 649
 650 static int add_sha1_to_array(const char *ref, const unsigned char *sha1,
 651                              int flags, void *data)
 652 {
 653         sha1_array_append(data, sha1);
 654         return 0;
 655 }
 656
 657 void check_for_new_submodule_commits(unsigned char new_sha1[20])
 658 {
 659         if (!initialized_fetch_ref_tips) {
 660                 for_each_ref(add_sha1_to_array, &ref_tips_before_fetch);
 661                 initialized_fetch_ref_tips = 1;
 662         }
 663
 664         sha1_array_append(&ref_tips_after_fetch, new_sha1);
 665 }
 666
 667 static void add_sha1_to_argv(const unsigned char sha1[20], void *data)
 668 {
 669         argv_array_push(data, sha1_to_hex(sha1));
 670 }
 671
 672 static void calculate_changed_submodule_paths(void)
 673 {
 674         struct rev_info rev;
 675         struct commit *commit;
 676         struct argv_array argv = ARGV_ARRAY_INIT;
 677
 678         /* No need to check if there are no submodules configured */
 679         if (!config_name_for_path.nr)
 680                 return;
 681
 682         init_revisions(&rev, NULL);
 683         argv_array_push(&argv, "--"); /* argv[0] program name */
 684         sha1_array_for_each_unique(&ref_tips_after_fetch,
 685                                    add_sha1_to_argv, &argv);
 686         argv_array_push(&argv, "--not");
 687         sha1_array_for_each_unique(&ref_tips_before_fetch,
 688                                    add_sha1_to_argv, &argv);
 689         setup_revisions(argv.argc, argv.argv, &rev, NULL);
 690         if (prepare_revision_walk(&rev))
 691                 die("revision walk setup failed");
 692
 693         /*
 694          * Collect all submodules (whether checked out or not) for which new
 695          * commits have been recorded upstream in "changed_submodule_paths".
 696          */
 697         while ((commit = get_revision(&rev))) {
 698                 struct commit_list *parent = commit->parents;
 699                 while (parent) {
 700                         struct diff_options diff_opts;
 701                         diff_setup(&diff_opts);
 702                         DIFF_OPT_SET(&diff_opts, RECURSIVE);
 703                         diff_opts.output_format |= DIFF_FORMAT_CALLBACK;
 704                         diff_opts.format_callback = submodule_collect_changed_cb;
 705                         diff_setup_done(&diff_opts);
 706                         diff_tree_sha1(parent->item->object.sha1, commit->object.sha1, "", &diff_opts);
 707                         diffcore_std(&diff_opts);
 708                         diff_flush(&diff_opts);
 709                         parent = parent->next;
 710                 }
 711         }
 712
 713         argv_array_clear(&argv);
 714         sha1_array_clear(&ref_tips_before_fetch);
 715         sha1_array_clear(&ref_tips_after_fetch);
 716         initialized_fetch_ref_tips = 0;
 717 }
 718
 719 int fetch_populated_submodules(const struct argv_array *options,
 720                                const char *prefix, int command_line_option,
 721                                int quiet)
 722 {
 723         int i, result = 0;
 724         struct child_process cp;
 725         struct argv_array argv = ARGV_ARRAY_INIT;
 726         struct string_list_item *name_for_path;
 727         const char *work_tree = get_git_work_tree();
 728         if (!work_tree)
 729                 goto out;
 730
 731         if (read_cache() < 0)
 732                 die("index file corrupt");
 733
 734         argv_array_push(&argv, "fetch");
 735         for (i = 0; i < options->argc; i++)
 736                 argv_array_push(&argv, options->argv[i]);
 737         argv_array_push(&argv, "--recurse-submodules-default");
 738         /* default value, "--submodule-prefix" and its value are added later */
 739
 740         memset(&cp, 0, sizeof(cp));
 741         cp.env = local_repo_env;
 742         cp.git_cmd = 1;
 743         cp.no_stdin = 1;
 744
 745         calculate_changed_submodule_paths();
 746
 747         for (i = 0; i < active_nr; i++) {
 748                 struct strbuf submodule_path = STRBUF_INIT;
 749                 struct strbuf submodule_git_dir = STRBUF_INIT;
 750                 struct strbuf submodule_prefix = STRBUF_INIT;
 751                 const struct cache_entry *ce = active_cache[i];
 752                 const char *git_dir, *name, *default_argv;
 753
 754                 if (!S_ISGITLINK(ce->ce_mode))
 755                         continue;
 756
 757                 name = ce->name;
 758                 name_for_path = unsorted_string_list_lookup(&config_name_for_path, ce->name);
 759                 if (name_for_path)
 760                         name = name_for_path->util;
 761
 762                 default_argv = "yes";
 763                 if (command_line_option == RECURSE_SUBMODULES_DEFAULT) {
 764                         struct string_list_item *fetch_recurse_submodules_option;
 765                         fetch_recurse_submodules_option = unsorted_string_list_lookup(&config_fetch_recurse_submodules_for_name, name);
 766                         if (fetch_recurse_submodules_option) {
 767                                 if ((intptr_t)fetch_recurse_submodules_option->util == RECURSE_SUBMODULES_OFF)
 768                                         continue;
 769                                 if ((intptr_t)fetch_recurse_submodules_option->util == RECURSE_SUBMODULES_ON_DEMAND) {
 770                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
 771                                                 continue;
 772                                         default_argv = "on-demand";
 773                                 }
 774                         } else {
 775                                 if ((config_fetch_recurse_submodules == RECURSE_SUBMODULES_OFF) ||
 776                                     gitmodules_is_unmerged)
 777                                         continue;
 778                                 if (config_fetch_recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND) {
 779                                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
 780                                                 continue;
 781                                         default_argv = "on-demand";
 782                                 }
 783                         }
 784                 } else if (command_line_option == RECURSE_SUBMODULES_ON_DEMAND) {
 785                         if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
 786                                 continue;
 787                         default_argv = "on-demand";
 788                 }
 789
 790                 strbuf_addf(&submodule_path, "%s/%s", work_tree, ce->name);
 791                 strbuf_addf(&submodule_git_dir, "%s/.git", submodule_path.buf);
 792                 strbuf_addf(&submodule_prefix, "%s%s/", prefix, ce->name);
 793                 git_dir = read_gitfile(submodule_git_dir.buf);
 794                 if (!git_dir)
 795                         git_dir = submodule_git_dir.buf;
 796                 if (is_directory(git_dir)) {
 797                         if (!quiet)
 798                                 printf("Fetching submodule %s%s\n", prefix, ce->name);
 799                         cp.dir = submodule_path.buf;
 800                         argv_array_push(&argv, default_argv);
 801                         argv_array_push(&argv, "--submodule-prefix");
 802                         argv_array_push(&argv, submodule_prefix.buf);
 803                         cp.argv = argv.argv;
 804                         if (run_command(&cp))
 805                                 result = 1;
 806                         argv_array_pop(&argv);
 807                         argv_array_pop(&argv);
 808                         argv_array_pop(&argv);
 809                 }
 810                 strbuf_release(&submodule_path);
 811                 strbuf_release(&submodule_git_dir);
 812                 strbuf_release(&submodule_prefix);
 813         }
 814         argv_array_clear(&argv);
 815 out:
 816         string_list_clear(&changed_submodule_paths, 1);
 817         return result;
 818 }
 819
 820 unsigned is_submodule_modified(const char *path, int ignore_untracked)
 821 {
 822         ssize_t len;
 823         struct child_process cp;
 824         const char *argv[] = {
 825                 "status",
 826                 "--porcelain",
 827                 NULL,
 828                 NULL,
 829         };
 830         struct strbuf buf = STRBUF_INIT;
 831         unsigned dirty_submodule = 0;
 832         const char *line, *next_line;
 833         const char *git_dir;
 834
 835         strbuf_addf(&buf, "%s/.git", path);
 836         git_dir = read_gitfile(buf.buf);
 837         if (!git_dir)
 838                 git_dir = buf.buf;
 839         if (!is_directory(git_dir)) {
 840                 strbuf_release(&buf);
 841                 /* The submodule is not checked out, so it is not modified */
 842                 return 0;
 843
 844         }
 845         strbuf_reset(&buf);
 846
 847         if (ignore_untracked)
 848                 argv[2] = "-uno";
 849
 850         memset(&cp, 0, sizeof(cp));
 851         cp.argv = argv;
 852         cp.env = local_repo_env;
 853         cp.git_cmd = 1;
 854         cp.no_stdin = 1;
 855         cp.out = -1;
 856         cp.dir = path;
 857         if (start_command(&cp))
 858                 die("Could not run 'git status --porcelain' in submodule %s", path);
 859
 860         len = strbuf_read(&buf, cp.out, 1024);
 861         line = buf.buf;
 862         while (len > 2) {
 863                 if ((line[0] == '?') && (line[1] == '?')) {
 864                         dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
 865                         if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
 866                                 break;
 867                 } else {
 868                         dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
 869                         if (ignore_untracked ||
 870                             (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED))
 871                                 break;
 872                 }
 873                 next_line = strchr(line, '\n');
 874                 if (!next_line)
 875                         break;
 876                 next_line++;
 877                 len -= (next_line - line);
 878                 line = next_line;
 879         }
 880         close(cp.out);
 881
 882         if (finish_command(&cp))
 883                 die("'git status --porcelain' failed in submodule %s", path);
 884
 885         strbuf_release(&buf);
 886         return dirty_submodule;
 887 }
 888
 889 int submodule_uses_gitfile(const char *path)
 890 {
 891         struct child_process cp;
 892         const char *argv[] = {
 893                 "submodule",
 894                 "foreach",
 895                 "--quiet",
 896                 "--recursive",
 897                 "test -f .git",
 898                 NULL,
 899         };
 900         struct strbuf buf = STRBUF_INIT;
 901         const char *git_dir;
 902
 903         strbuf_addf(&buf, "%s/.git", path);
 904         git_dir = read_gitfile(buf.buf);
 905         if (!git_dir) {
 906                 strbuf_release(&buf);
 907                 return 0;
 908         }
 909         strbuf_release(&buf);
 910
 911         /* Now test that all nested submodules use a gitfile too */
 912         memset(&cp, 0, sizeof(cp));
 913         cp.argv = argv;
 914         cp.env = local_repo_env;
 915         cp.git_cmd = 1;
 916         cp.no_stdin = 1;
 917         cp.no_stderr = 1;
 918         cp.no_stdout = 1;
 919         cp.dir = path;
 920         if (run_command(&cp))
 921                 return 0;
 922
 923         return 1;
 924 }
 925
 926 int ok_to_remove_submodule(const char *path)
 927 {
 928         struct stat st;
 929         ssize_t len;
 930         struct child_process cp;
 931         const char *argv[] = {
 932                 "status",
 933                 "--porcelain",
 934                 "-u",
 935                 "--ignore-submodules=none",
 936                 NULL,
 937         };
 938         struct strbuf buf = STRBUF_INIT;
 939         int ok_to_remove = 1;
 940
 941         if ((lstat(path, &st) < 0) || is_empty_dir(path))
 942                 return 1;
 943
 944         if (!submodule_uses_gitfile(path))
 945                 return 0;
 946
 947         memset(&cp, 0, sizeof(cp));
 948         cp.argv = argv;
 949         cp.env = local_repo_env;
 950         cp.git_cmd = 1;
 951         cp.no_stdin = 1;
 952         cp.out = -1;
 953         cp.dir = path;
 954         if (start_command(&cp))
 955                 die("Could not run 'git status --porcelain -uall --ignore-submodules=none' in submodule %s", path);
 956
 957         len = strbuf_read(&buf, cp.out, 1024);
 958         if (len > 2)
 959                 ok_to_remove = 0;
 960         close(cp.out);
 961
 962         if (finish_command(&cp))
 963                 die("'git status --porcelain -uall --ignore-submodules=none' failed in submodule %s", path);
 964
 965         strbuf_release(&buf);
 966         return ok_to_remove;
 967 }
 968
 969 static int find_first_merges(struct object_array *result, const char *path,
 970                 struct commit *a, struct commit *b)
 971 {
 972         int i, j;
 973         struct object_array merges = OBJECT_ARRAY_INIT;
 974         struct commit *commit;
 975         int contains_another;
 976
 977         char merged_revision[42];
 978         const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path",
 979                                    "--all", merged_revision, NULL };
 980         struct rev_info revs;
 981         struct setup_revision_opt rev_opts;
 982
 983         memset(result, 0, sizeof(struct object_array));
 984         memset(&rev_opts, 0, sizeof(rev_opts));
 985
 986         /* get all revisions that merge commit a */
 987         snprintf(merged_revision, sizeof(merged_revision), "^%s",
 988                         sha1_to_hex(a->object.sha1));
 989         init_revisions(&revs, NULL);
 990         rev_opts.submodule = path;
 991         setup_revisions(sizeof(rev_args)/sizeof(char *)-1, rev_args, &revs, &rev_opts);
 992
 993         /* save all revisions from the above list that contain b */
 994         if (prepare_revision_walk(&revs))
 995                 die("revision walk setup failed");
 996         while ((commit = get_revision(&revs)) != NULL) {
 997                 struct object *o = &(commit->object);
 998                 if (in_merge_bases(b, commit))
 999                         add_object_array(o, NULL, &merges);
1000         }
1001         reset_revision_walk();
1002
1003         /* Now we've got all merges that contain a and b. Prune all
1004          * merges that contain another found merge and save them in
1005          * result.
1006          */
1007         for (i = 0; i < merges.nr; i++) {
1008                 struct commit *m1 = (struct commit *) merges.objects[i].item;
1009
1010                 contains_another = 0;
1011                 for (j = 0; j < merges.nr; j++) {
1012                         struct commit *m2 = (struct commit *) merges.objects[j].item;
1013                         if (i != j && in_merge_bases(m2, m1)) {
1014                                 contains_another = 1;
1015                                 break;
1016                         }
1017                 }
1018
1019                 if (!contains_another)
1020                         add_object_array(merges.objects[i].item, NULL, result);
1021         }
1022
1023         free(merges.objects);
1024         return result->nr;
1025 }
1026
1027 static void print_commit(struct commit *commit)
1028 {
1029         struct strbuf sb = STRBUF_INIT;
1030         struct pretty_print_context ctx = {0};
1031         ctx.date_mode = DATE_NORMAL;
1032         format_commit_message(commit, " %h: %m %s", &sb, &ctx);
1033         fprintf(stderr, "%s\n", sb.buf);
1034         strbuf_release(&sb);
1035 }
1036
1037 #define MERGE_WARNING(path, msg) \
1038         warning("Failed to merge submodule %s (%s)", path, msg);
1039
1040 int merge_submodule(unsigned char result[20], const char *path,
1041                     const unsigned char base[20], const unsigned char a[20],
1042                     const unsigned char b[20], int search)
1043 {
1044         struct commit *commit_base, *commit_a, *commit_b;
1045         int parent_count;
1046         struct object_array merges;
1047
1048         int i;
1049
1050         /* store a in result in case we fail */
1051         hashcpy(result, a);
1052
1053         /* we can not handle deletion conflicts */
1054         if (is_null_sha1(base))
1055                 return 0;
1056         if (is_null_sha1(a))
1057                 return 0;
1058         if (is_null_sha1(b))
1059                 return 0;
1060
1061         if (add_submodule_odb(path)) {
1062                 MERGE_WARNING(path, "not checked out");
1063                 return 0;
1064         }
1065
1066         if (!(commit_base = lookup_commit_reference(base)) ||
1067             !(commit_a = lookup_commit_reference(a)) ||
1068             !(commit_b = lookup_commit_reference(b))) {
1069                 MERGE_WARNING(path, "commits not present");
1070                 return 0;
1071         }
1072
1073         /* check whether both changes are forward */
1074         if (!in_merge_bases(commit_base, commit_a) ||
1075             !in_merge_bases(commit_base, commit_b)) {
1076                 MERGE_WARNING(path, "commits don't follow merge-base");
1077                 return 0;
1078         }
1079
1080         /* Case #1: a is contained in b or vice versa */
1081         if (in_merge_bases(commit_a, commit_b)) {
1082                 hashcpy(result, b);
1083                 return 1;
1084         }
1085         if (in_merge_bases(commit_b, commit_a)) {
1086                 hashcpy(result, a);
1087                 return 1;
1088         }
1089
1090         /*
1091          * Case #2: There are one or more merges that contain a and b in
1092          * the submodule. If there is only one, then present it as a
1093          * suggestion to the user, but leave it marked unmerged so the
1094          * user needs to confirm the resolution.
1095          */
1096
1097         /* Skip the search if makes no sense to the calling context.  */
1098         if (!search)
1099                 return 0;
1100
1101         /* find commit which merges them */
1102         parent_count = find_first_merges(&merges, path, commit_a, commit_b);
1103         switch (parent_count) {
1104         case 0:
1105                 MERGE_WARNING(path, "merge following commits not found");
1106                 break;
1107
1108         case 1:
1109                 MERGE_WARNING(path, "not fast-forward");
1110                 fprintf(stderr, "Found a possible merge resolution "
1111                                 "for the submodule:\n");
1112                 print_commit((struct commit *) merges.objects[0].item);
1113                 fprintf(stderr,
1114                         "If this is correct simply add it to the index "
1115                         "for example\n"
1116                         "by using:\n\n"
1117                         "  git update-index --cacheinfo 160000 %s \"%s\"\n\n"
1118                         "which will accept this suggestion.\n",
1119                         sha1_to_hex(merges.objects[0].item->sha1), path);
1120                 break;
1121
1122         default:
1123                 MERGE_WARNING(path, "multiple merges found");
1124                 for (i = 0; i < merges.nr; i++)
1125                         print_commit((struct commit *) merges.objects[i].item);
1126         }
1127
1128         free(merges.objects);
1129         return 0;
1130 }
1131
1132 /* Update gitfile and core.worktree setting to connect work tree and git dir */
1133 void connect_work_tree_and_git_dir(const char *work_tree, const char *git_dir)
1134 {
1135         struct strbuf file_name = STRBUF_INIT;
1136         struct strbuf rel_path = STRBUF_INIT;
1137         const char *real_work_tree = xstrdup(real_path(work_tree));
1138         FILE *fp;
1139
1140         /* Update gitfile */
1141         strbuf_addf(&file_name, "%s/.git", work_tree);
1142         fp = fopen(file_name.buf, "w");
1143         if (!fp)
1144                 die(_("Could not create git link %s"), file_name.buf);
1145         fprintf(fp, "gitdir: %s\n", relative_path(git_dir, real_work_tree,
1146                                                   &rel_path));
1147         fclose(fp);
1148
1149         /* Update core.worktree setting */
1150         strbuf_reset(&file_name);
1151         strbuf_addf(&file_name, "%s/config", git_dir);
1152         if (git_config_set_in_file(file_name.buf, "core.worktree",
1153                                    relative_path(real_work_tree, git_dir,
1154                                                  &rel_path)))
1155                 die(_("Could not set core.worktree in %s"),
1156                     file_name.buf);
1157
1158         strbuf_release(&file_name);
1159         strbuf_release(&rel_path);
1160         free((void *)real_work_tree);
1161 }