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