2 * GIT - The information manager from hell
4 * Copyright (C) Linus Torvalds, 2005
18 static int update = 0;
19 static int index_only = 0;
20 static int nontrivial_merge = 0;
21 static int trivial_merges_only = 0;
22 static int aggressive = 0;
23 static int verbose_update = 0;
24 static volatile int progress_update = 0;
26 static int head_idx = -1;
27 static int merge_size = 0;
29 static struct object_list *trees = NULL;
31 static struct cache_entry df_conflict_entry = {
34 static struct tree_entry_list df_conflict_list = {
36 .next = &df_conflict_list
39 typedef int (*merge_fn_t)(struct cache_entry **src);
41 static int entcmp(const char *name1, int dir1, const char *name2, int dir2)
43 int len1 = strlen(name1);
44 int len2 = strlen(name2);
45 int len = len1 < len2 ? len1 : len2;
46 int ret = memcmp(name1, name2, len);
56 ret = (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0;
62 static int unpack_trees_rec(struct tree_entry_list **posns, int len,
63 const char *base, merge_fn_t fn, int *indpos)
65 int baselen = strlen(base);
66 int src_size = len + 1;
73 struct tree_entry_list **subposns;
74 struct cache_entry **src;
80 /* Find the first name in the input. */
86 if (merge && *indpos < active_nr) {
87 /* This is a bit tricky: */
88 /* If the index has a subdirectory (with
89 * contents) as the first name, it'll get a
90 * filename like "foo/bar". But that's after
91 * "foo", so the entry in trees will get
92 * handled first, at which point we'll go into
93 * "foo", and deal with "bar" from the index,
94 * because the base will be "foo/". The only
95 * way we can actually have "foo/bar" first of
96 * all the things is if the trees don't
97 * contain "foo" at all, in which case we'll
98 * handle "foo/bar" without going into the
99 * directory, but that's fine (and will return
100 * an error anyway, with the added unknown
104 cache_name = active_cache[*indpos]->name;
105 if (strlen(cache_name) > baselen &&
106 !memcmp(cache_name, base, baselen)) {
107 cache_name += baselen;
116 printf("index %s\n", first);
118 for (i = 0; i < len; i++) {
119 if (!posns[i] || posns[i] == &df_conflict_list)
122 printf("%d %s\n", i + 1, posns[i]->name);
124 if (!first || entcmp(first, firstdir,
126 posns[i]->directory) > 0) {
127 first = posns[i]->name;
128 firstdir = posns[i]->directory;
131 /* No name means we're done */
135 pathlen = strlen(first);
136 ce_size = cache_entry_size(baselen + pathlen);
138 src = xcalloc(src_size, sizeof(struct cache_entry *));
140 subposns = xcalloc(len, sizeof(struct tree_list_entry *));
142 if (cache_name && !strcmp(cache_name, first)) {
144 src[0] = active_cache[*indpos];
145 remove_cache_entry_at(*indpos);
148 for (i = 0; i < len; i++) {
149 struct cache_entry *ce;
152 (posns[i] != &df_conflict_list &&
153 strcmp(first, posns[i]->name))) {
157 if (posns[i] == &df_conflict_list) {
158 src[i + merge] = &df_conflict_entry;
162 if (posns[i]->directory) {
163 struct tree *tree = lookup_tree(posns[i]->sha1);
166 subposns[i] = create_tree_entry_list(tree);
167 posns[i] = posns[i]->next;
168 src[i + merge] = &df_conflict_entry;
174 else if (i + 1 < head_idx)
176 else if (i + 1 > head_idx)
181 ce = xcalloc(1, ce_size);
182 ce->ce_mode = create_ce_mode(posns[i]->mode);
183 ce->ce_flags = create_ce_flags(baselen + pathlen,
185 memcpy(ce->name, base, baselen);
186 memcpy(ce->name + baselen, first, pathlen + 1);
190 memcpy(ce->sha1, posns[i]->sha1, 20);
192 subposns[i] = &df_conflict_list;
193 posns[i] = posns[i]->next;
200 printf("%s:\n", first);
201 for (i = 0; i < src_size; i++) {
204 printf("%s\n", sha1_to_hex(src[i]->sha1));
212 printf("Added %d entries\n", ret);
216 for (i = 0; i < src_size; i++) {
218 add_cache_entry(src[i], ADD_CACHE_OK_TO_ADD|ADD_CACHE_SKIP_DFCHECK);
224 char *newbase = xmalloc(baselen + 2 + pathlen);
225 memcpy(newbase, base, baselen);
226 memcpy(newbase + baselen, first, pathlen);
227 newbase[baselen + pathlen] = '/';
228 newbase[baselen + pathlen + 1] = '\0';
229 if (unpack_trees_rec(subposns, len, newbase, fn,
239 static void reject_merge(struct cache_entry *ce)
241 die("Entry '%s' would be overwritten by merge. Cannot merge.",
245 /* Unlink the last component and attempt to remove leading
246 * directories, in case this unlink is the removal of the
247 * last entry in the directory -- empty directories are removed.
249 static void unlink_entry(char *name)
258 cp = strrchr(name, '/');
265 status = rmdir(name);
274 static void progress_interval(int signum)
279 static void setup_progress_signal(void)
284 memset(&sa, 0, sizeof(sa));
285 sa.sa_handler = progress_interval;
286 sigemptyset(&sa.sa_mask);
287 sa.sa_flags = SA_RESTART;
288 sigaction(SIGALRM, &sa, NULL);
290 v.it_interval.tv_sec = 1;
291 v.it_interval.tv_usec = 0;
292 v.it_value = v.it_interval;
293 setitimer(ITIMER_REAL, &v, NULL);
296 static void check_updates(struct cache_entry **src, int nr)
298 static struct checkout state = {
304 unsigned short mask = htons(CE_UPDATE);
305 unsigned last_percent = 200, cnt = 0, total = 0;
307 if (update && verbose_update) {
308 for (total = cnt = 0; cnt < nr; cnt++) {
309 struct cache_entry *ce = src[cnt];
310 if (!ce->ce_mode || ce->ce_flags & mask)
314 /* Don't bother doing this for very small updates */
319 fprintf(stderr, "Checking files out...\n");
320 setup_progress_signal();
327 struct cache_entry *ce = *src++;
330 if (!ce->ce_mode || ce->ce_flags & mask) {
333 percent = (cnt * 100) / total;
334 if (percent != last_percent ||
336 fprintf(stderr, "%4u%% (%u/%u) done\r",
337 percent, cnt, total);
338 last_percent = percent;
344 unlink_entry(ce->name);
347 if (ce->ce_flags & mask) {
348 ce->ce_flags &= ~mask;
350 checkout_entry(ce, &state, NULL);
354 signal(SIGALRM, SIG_IGN);
359 static int unpack_trees(merge_fn_t fn)
362 unsigned len = object_list_length(trees);
363 struct tree_entry_list **posns;
365 struct object_list *posn = trees;
369 posns = xmalloc(len * sizeof(struct tree_entry_list *));
370 for (i = 0; i < len; i++) {
371 posns[i] = create_tree_entry_list((struct tree *) posn->item);
374 if (unpack_trees_rec(posns, len, "", fn, &indpos))
378 if (trivial_merges_only && nontrivial_merge)
379 die("Merge requires file-level merging");
381 check_updates(active_cache, active_nr);
385 static int list_tree(unsigned char *sha1)
387 struct tree *tree = parse_tree_indirect(sha1);
390 object_list_append(&tree->object, &trees);
394 static int same(struct cache_entry *a, struct cache_entry *b)
400 return a->ce_mode == b->ce_mode &&
401 !memcmp(a->sha1, b->sha1, 20);
406 * When a CE gets turned into an unmerged entry, we
407 * want it to be up-to-date
409 static void verify_uptodate(struct cache_entry *ce)
413 if (index_only || reset)
416 if (!lstat(ce->name, &st)) {
417 unsigned changed = ce_match_stat(ce, &st, 1);
423 ce->ce_flags |= htons(CE_UPDATE);
428 die("Entry '%s' not uptodate. Cannot merge.", ce->name);
432 * We do not want to remove or overwrite a working tree file that
435 static void verify_absent(const char *path, const char *action)
439 if (index_only || reset || !update)
441 if (!lstat(path, &st))
442 die("Untracked working tree file '%s' "
443 "would be %s by merge.", path, action);
446 static int merged_entry(struct cache_entry *merge, struct cache_entry *old)
448 merge->ce_flags |= htons(CE_UPDATE);
451 * See if we can re-use the old CE directly?
452 * That way we get the uptodate stat info.
454 * This also removes the UPDATE flag on
457 if (same(old, merge)) {
460 verify_uptodate(old);
464 verify_absent(merge->name, "overwritten");
466 merge->ce_flags &= ~htons(CE_STAGEMASK);
467 add_cache_entry(merge, ADD_CACHE_OK_TO_ADD);
471 static int deleted_entry(struct cache_entry *ce, struct cache_entry *old)
474 verify_uptodate(old);
476 verify_absent(ce->name, "removed");
478 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD);
482 static int keep_entry(struct cache_entry *ce)
484 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD);
489 static void show_stage_entry(FILE *o,
490 const char *label, const struct cache_entry *ce)
493 fprintf(o, "%s (missing)\n", label);
495 fprintf(o, "%s%06o %s %d\t%s\n",
498 sha1_to_hex(ce->sha1),
504 static int threeway_merge(struct cache_entry **stages)
506 struct cache_entry *index;
507 struct cache_entry *head;
508 struct cache_entry *remote = stages[head_idx + 1];
511 int remote_match = 0;
512 const char *path = NULL;
514 int df_conflict_head = 0;
515 int df_conflict_remote = 0;
517 int any_anc_missing = 0;
518 int no_anc_exists = 1;
521 for (i = 1; i < head_idx; i++) {
526 path = stages[i]->name;
532 head = stages[head_idx];
534 if (head == &df_conflict_entry) {
535 df_conflict_head = 1;
539 if (remote == &df_conflict_entry) {
540 df_conflict_remote = 1;
551 /* First, if there's a #16 situation, note that to prevent #13
554 if (!same(remote, head)) {
555 for (i = 1; i < head_idx; i++) {
556 if (same(stages[i], head)) {
559 if (same(stages[i], remote)) {
565 /* We start with cases where the index is allowed to match
566 * something other than the head: #14(ALT) and #2ALT, where it
567 * is permitted to match the result instead.
569 /* #14, #14ALT, #2ALT */
570 if (remote && !df_conflict_head && head_match && !remote_match) {
571 if (index && !same(index, remote) && !same(index, head))
573 return merged_entry(remote, index);
576 * If we have an entry in the index cache, then we want to
577 * make sure that it matches head.
579 if (index && !same(index, head)) {
585 if (same(head, remote))
586 return merged_entry(head, index);
588 if (!df_conflict_remote && remote_match && !head_match)
589 return merged_entry(head, index);
593 if (!head && !remote && any_anc_missing)
596 /* Under the new "aggressive" rule, we resolve mostly trivial
597 * cases that we historically had git-merge-one-file resolve.
600 int head_deleted = !head && !df_conflict_head;
601 int remote_deleted = !remote && !df_conflict_remote;
604 * Deleted in one and unchanged in the other.
606 if ((head_deleted && remote_deleted) ||
607 (head_deleted && remote && remote_match) ||
608 (remote_deleted && head && head_match)) {
610 return deleted_entry(index, index);
612 verify_absent(path, "removed");
616 * Added in both, identically.
618 if (no_anc_exists && head && remote && same(head, remote))
619 return merged_entry(head, index);
623 /* Below are "no merge" cases, which require that the index be
624 * up-to-date to avoid the files getting overwritten with
625 * conflict resolution files.
628 verify_uptodate(index);
631 verify_absent(path, "overwritten");
633 nontrivial_merge = 1;
635 /* #2, #3, #4, #6, #7, #9, #11. */
637 if (!head_match || !remote_match) {
638 for (i = 1; i < head_idx; i++) {
640 keep_entry(stages[i]);
648 fprintf(stderr, "read-tree: warning #16 detected\n");
649 show_stage_entry(stderr, "head ", stages[head_match]);
650 show_stage_entry(stderr, "remote ", stages[remote_match]);
653 if (head) { count += keep_entry(head); }
654 if (remote) { count += keep_entry(remote); }
661 * The rule is to "carry forward" what is in the index without losing
662 * information across a "fast forward", favoring a successful merge
663 * over a merge failure when it makes sense. For details of the
664 * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
667 static int twoway_merge(struct cache_entry **src)
669 struct cache_entry *current = src[0];
670 struct cache_entry *oldtree = src[1], *newtree = src[2];
673 return error("Cannot do a twoway merge of %d trees",
677 if ((!oldtree && !newtree) || /* 4 and 5 */
678 (!oldtree && newtree &&
679 same(current, newtree)) || /* 6 and 7 */
680 (oldtree && newtree &&
681 same(oldtree, newtree)) || /* 14 and 15 */
682 (oldtree && newtree &&
683 !same(oldtree, newtree) && /* 18 and 19*/
684 same(current, newtree))) {
685 return keep_entry(current);
687 else if (oldtree && !newtree && same(current, oldtree)) {
689 return deleted_entry(oldtree, current);
691 else if (oldtree && newtree &&
692 same(current, oldtree) && !same(current, newtree)) {
694 return merged_entry(newtree, current);
697 /* all other failures */
699 reject_merge(oldtree);
701 reject_merge(current);
703 reject_merge(newtree);
708 return merged_entry(newtree, current);
710 return deleted_entry(oldtree, current);
717 * - take the stat information from stage0, take the data from stage1
719 static int oneway_merge(struct cache_entry **src)
721 struct cache_entry *old = src[0];
722 struct cache_entry *a = src[1];
725 return error("Cannot do a oneway merge of %d trees",
729 return deleted_entry(old, old);
730 if (old && same(old, a)) {
733 if (lstat(old->name, &st) ||
734 ce_match_stat(old, &st, 1))
735 old->ce_flags |= htons(CE_UPDATE);
737 return keep_entry(old);
739 return merged_entry(a, old);
742 static int read_cache_unmerged(void)
745 struct cache_entry **dst;
750 for (i = 0; i < active_nr; i++) {
751 struct cache_entry *ce = active_cache[i];
760 active_nr -= deleted;
764 static const char read_tree_usage[] = "git-read-tree (<sha> | -m [--aggressive] [-u | -i] <sha1> [<sha2> [<sha3>]])";
766 static struct cache_file cache_file;
768 int cmd_read_tree(int argc, const char **argv, char **envp)
770 int i, newfd, stage = 0;
771 unsigned char sha1[20];
772 merge_fn_t fn = NULL;
774 setup_git_directory();
775 git_config(git_default_config);
777 newfd = hold_index_file_for_update(&cache_file, get_index_file());
779 die("unable to create new cachefile");
781 git_config(git_default_config);
785 for (i = 1; i < argc; i++) {
786 const char *arg = argv[i];
788 /* "-u" means "update", meaning that a merge will update
791 if (!strcmp(arg, "-u")) {
796 if (!strcmp(arg, "-v")) {
801 /* "-i" means "index only", meaning that a merge will
802 * not even look at the working tree.
804 if (!strcmp(arg, "-i")) {
809 /* This differs from "-m" in that we'll silently ignore unmerged entries */
810 if (!strcmp(arg, "--reset")) {
812 usage(read_tree_usage);
816 read_cache_unmerged();
820 if (!strcmp(arg, "--trivial")) {
821 trivial_merges_only = 1;
825 if (!strcmp(arg, "--aggressive")) {
830 /* "-m" stands for "merge", meaning we start in stage 1 */
831 if (!strcmp(arg, "-m")) {
833 usage(read_tree_usage);
834 if (read_cache_unmerged())
835 die("you need to resolve your current index first");
841 /* using -u and -i at the same time makes no sense */
842 if (1 < index_only + update)
843 usage(read_tree_usage);
845 if (get_sha1(arg, sha1))
846 die("Not a valid object name %s", arg);
847 if (list_tree(sha1) < 0)
848 die("failed to unpack tree object %s", arg);
851 if ((update||index_only) && !merge)
852 usage(read_tree_usage);
856 die("just how do you expect me to merge %d trees?", stage-1);
873 head_idx = stage - 2;
879 if (write_cache(newfd, active_cache, active_nr) ||
880 commit_index_file(&cache_file))
881 die("unable to write new index file");