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