2 * GIT - The information manager from hell
4 * Copyright (C) Linus Torvalds, 2005
12 #include "tree-walk.h"
13 #include "cache-tree.h"
20 static int update = 0;
21 static int index_only = 0;
22 static int nontrivial_merge = 0;
23 static int trivial_merges_only = 0;
24 static int aggressive = 0;
25 static int verbose_update = 0;
26 static volatile int progress_update = 0;
28 static int head_idx = -1;
29 static int merge_size = 0;
31 static struct object_list *trees = NULL;
33 static struct cache_entry df_conflict_entry = {
36 struct tree_entry_list {
37 struct tree_entry_list *next;
38 unsigned directory : 1;
39 unsigned executable : 1;
43 const unsigned char *sha1;
46 static struct tree_entry_list df_conflict_list = {
48 .next = &df_conflict_list
51 typedef int (*merge_fn_t)(struct cache_entry **src);
53 static struct tree_entry_list *create_tree_entry_list(struct tree *tree)
55 struct tree_desc desc;
56 struct name_entry one;
57 struct tree_entry_list *ret = NULL;
58 struct tree_entry_list **list_p = &ret;
60 desc.buf = tree->buffer;
61 desc.size = tree->size;
63 while (tree_entry(&desc, &one)) {
64 struct tree_entry_list *entry;
66 entry = xmalloc(sizeof(struct tree_entry_list));
67 entry->name = one.path;
68 entry->sha1 = one.sha1;
69 entry->mode = one.mode;
70 entry->directory = S_ISDIR(one.mode) != 0;
71 entry->executable = (one.mode & S_IXUSR) != 0;
72 entry->symlink = S_ISLNK(one.mode) != 0;
76 list_p = &entry->next;
81 static int entcmp(const char *name1, int dir1, const char *name2, int dir2)
83 int len1 = strlen(name1);
84 int len2 = strlen(name2);
85 int len = len1 < len2 ? len1 : len2;
86 int ret = memcmp(name1, name2, len);
96 ret = (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0;
102 static int unpack_trees_rec(struct tree_entry_list **posns, int len,
103 const char *base, merge_fn_t fn, int *indpos)
105 int baselen = strlen(base);
106 int src_size = len + 1;
113 struct tree_entry_list **subposns;
114 struct cache_entry **src;
120 /* Find the first name in the input. */
125 /* Check the cache */
126 if (merge && *indpos < active_nr) {
127 /* This is a bit tricky: */
128 /* If the index has a subdirectory (with
129 * contents) as the first name, it'll get a
130 * filename like "foo/bar". But that's after
131 * "foo", so the entry in trees will get
132 * handled first, at which point we'll go into
133 * "foo", and deal with "bar" from the index,
134 * because the base will be "foo/". The only
135 * way we can actually have "foo/bar" first of
136 * all the things is if the trees don't
137 * contain "foo" at all, in which case we'll
138 * handle "foo/bar" without going into the
139 * directory, but that's fine (and will return
140 * an error anyway, with the added unknown
144 cache_name = active_cache[*indpos]->name;
145 if (strlen(cache_name) > baselen &&
146 !memcmp(cache_name, base, baselen)) {
147 cache_name += baselen;
156 printf("index %s\n", first);
158 for (i = 0; i < len; i++) {
159 if (!posns[i] || posns[i] == &df_conflict_list)
162 printf("%d %s\n", i + 1, posns[i]->name);
164 if (!first || entcmp(first, firstdir,
166 posns[i]->directory) > 0) {
167 first = posns[i]->name;
168 firstdir = posns[i]->directory;
171 /* No name means we're done */
175 pathlen = strlen(first);
176 ce_size = cache_entry_size(baselen + pathlen);
178 src = xcalloc(src_size, sizeof(struct cache_entry *));
180 subposns = xcalloc(len, sizeof(struct tree_list_entry *));
182 if (cache_name && !strcmp(cache_name, first)) {
184 src[0] = active_cache[*indpos];
185 remove_cache_entry_at(*indpos);
188 for (i = 0; i < len; i++) {
189 struct cache_entry *ce;
192 (posns[i] != &df_conflict_list &&
193 strcmp(first, posns[i]->name))) {
197 if (posns[i] == &df_conflict_list) {
198 src[i + merge] = &df_conflict_entry;
202 if (posns[i]->directory) {
203 struct tree *tree = lookup_tree(posns[i]->sha1);
206 subposns[i] = create_tree_entry_list(tree);
207 posns[i] = posns[i]->next;
208 src[i + merge] = &df_conflict_entry;
214 else if (i + 1 < head_idx)
216 else if (i + 1 > head_idx)
221 ce = xcalloc(1, ce_size);
222 ce->ce_mode = create_ce_mode(posns[i]->mode);
223 ce->ce_flags = create_ce_flags(baselen + pathlen,
225 memcpy(ce->name, base, baselen);
226 memcpy(ce->name + baselen, first, pathlen + 1);
230 memcpy(ce->sha1, posns[i]->sha1, 20);
232 subposns[i] = &df_conflict_list;
233 posns[i] = posns[i]->next;
240 printf("%s:\n", first);
241 for (i = 0; i < src_size; i++) {
244 printf("%s\n", sha1_to_hex(src[i]->sha1));
252 printf("Added %d entries\n", ret);
256 for (i = 0; i < src_size; i++) {
258 add_cache_entry(src[i], ADD_CACHE_OK_TO_ADD|ADD_CACHE_SKIP_DFCHECK);
264 char *newbase = xmalloc(baselen + 2 + pathlen);
265 memcpy(newbase, base, baselen);
266 memcpy(newbase + baselen, first, pathlen);
267 newbase[baselen + pathlen] = '/';
268 newbase[baselen + pathlen + 1] = '\0';
269 if (unpack_trees_rec(subposns, len, newbase, fn,
279 static void reject_merge(struct cache_entry *ce)
281 die("Entry '%s' would be overwritten by merge. Cannot merge.",
285 /* Unlink the last component and attempt to remove leading
286 * directories, in case this unlink is the removal of the
287 * last entry in the directory -- empty directories are removed.
289 static void unlink_entry(char *name)
298 cp = strrchr(name, '/');
305 status = rmdir(name);
314 static void progress_interval(int signum)
319 static void setup_progress_signal(void)
324 memset(&sa, 0, sizeof(sa));
325 sa.sa_handler = progress_interval;
326 sigemptyset(&sa.sa_mask);
327 sa.sa_flags = SA_RESTART;
328 sigaction(SIGALRM, &sa, NULL);
330 v.it_interval.tv_sec = 1;
331 v.it_interval.tv_usec = 0;
332 v.it_value = v.it_interval;
333 setitimer(ITIMER_REAL, &v, NULL);
336 static void check_updates(struct cache_entry **src, int nr)
338 static struct checkout state = {
344 unsigned short mask = htons(CE_UPDATE);
345 unsigned last_percent = 200, cnt = 0, total = 0;
347 if (update && verbose_update) {
348 for (total = cnt = 0; cnt < nr; cnt++) {
349 struct cache_entry *ce = src[cnt];
350 if (!ce->ce_mode || ce->ce_flags & mask)
354 /* Don't bother doing this for very small updates */
359 fprintf(stderr, "Checking files out...\n");
360 setup_progress_signal();
367 struct cache_entry *ce = *src++;
370 if (!ce->ce_mode || ce->ce_flags & mask) {
373 percent = (cnt * 100) / total;
374 if (percent != last_percent ||
376 fprintf(stderr, "%4u%% (%u/%u) done\r",
377 percent, cnt, total);
378 last_percent = percent;
384 unlink_entry(ce->name);
387 if (ce->ce_flags & mask) {
388 ce->ce_flags &= ~mask;
390 checkout_entry(ce, &state, NULL);
394 signal(SIGALRM, SIG_IGN);
399 static int unpack_trees(merge_fn_t fn)
402 unsigned len = object_list_length(trees);
403 struct tree_entry_list **posns;
405 struct object_list *posn = trees;
409 posns = xmalloc(len * sizeof(struct tree_entry_list *));
410 for (i = 0; i < len; i++) {
411 posns[i] = create_tree_entry_list((struct tree *) posn->item);
414 if (unpack_trees_rec(posns, len, "", fn, &indpos))
418 if (trivial_merges_only && nontrivial_merge)
419 die("Merge requires file-level merging");
421 check_updates(active_cache, active_nr);
425 static int list_tree(unsigned char *sha1)
427 struct tree *tree = parse_tree_indirect(sha1);
430 object_list_append(&tree->object, &trees);
434 static int same(struct cache_entry *a, struct cache_entry *b)
440 return a->ce_mode == b->ce_mode &&
441 !memcmp(a->sha1, b->sha1, 20);
446 * When a CE gets turned into an unmerged entry, we
447 * want it to be up-to-date
449 static void verify_uptodate(struct cache_entry *ce)
453 if (index_only || reset)
456 if (!lstat(ce->name, &st)) {
457 unsigned changed = ce_match_stat(ce, &st, 1);
463 ce->ce_flags |= htons(CE_UPDATE);
468 die("Entry '%s' not uptodate. Cannot merge.", ce->name);
471 static void invalidate_ce_path(struct cache_entry *ce)
474 cache_tree_invalidate_path(active_cache_tree, ce->name);
478 * We do not want to remove or overwrite a working tree file that
481 static void verify_absent(const char *path, const char *action)
485 if (index_only || reset || !update)
487 if (!lstat(path, &st))
488 die("Untracked working tree file '%s' "
489 "would be %s by merge.", path, action);
492 static int merged_entry(struct cache_entry *merge, struct cache_entry *old)
494 merge->ce_flags |= htons(CE_UPDATE);
497 * See if we can re-use the old CE directly?
498 * That way we get the uptodate stat info.
500 * This also removes the UPDATE flag on
503 if (same(old, merge)) {
506 verify_uptodate(old);
507 invalidate_ce_path(old);
511 verify_absent(merge->name, "overwritten");
512 invalidate_ce_path(merge);
515 merge->ce_flags &= ~htons(CE_STAGEMASK);
516 add_cache_entry(merge, ADD_CACHE_OK_TO_ADD);
520 static int deleted_entry(struct cache_entry *ce, struct cache_entry *old)
523 verify_uptodate(old);
525 verify_absent(ce->name, "removed");
527 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD);
528 invalidate_ce_path(ce);
532 static int keep_entry(struct cache_entry *ce)
534 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD);
539 static void show_stage_entry(FILE *o,
540 const char *label, const struct cache_entry *ce)
543 fprintf(o, "%s (missing)\n", label);
545 fprintf(o, "%s%06o %s %d\t%s\n",
548 sha1_to_hex(ce->sha1),
554 static int threeway_merge(struct cache_entry **stages)
556 struct cache_entry *index;
557 struct cache_entry *head;
558 struct cache_entry *remote = stages[head_idx + 1];
561 int remote_match = 0;
562 const char *path = NULL;
564 int df_conflict_head = 0;
565 int df_conflict_remote = 0;
567 int any_anc_missing = 0;
568 int no_anc_exists = 1;
571 for (i = 1; i < head_idx; i++) {
576 path = stages[i]->name;
582 head = stages[head_idx];
584 if (head == &df_conflict_entry) {
585 df_conflict_head = 1;
589 if (remote == &df_conflict_entry) {
590 df_conflict_remote = 1;
601 /* First, if there's a #16 situation, note that to prevent #13
604 if (!same(remote, head)) {
605 for (i = 1; i < head_idx; i++) {
606 if (same(stages[i], head)) {
609 if (same(stages[i], remote)) {
615 /* We start with cases where the index is allowed to match
616 * something other than the head: #14(ALT) and #2ALT, where it
617 * is permitted to match the result instead.
619 /* #14, #14ALT, #2ALT */
620 if (remote && !df_conflict_head && head_match && !remote_match) {
621 if (index && !same(index, remote) && !same(index, head))
623 return merged_entry(remote, index);
626 * If we have an entry in the index cache, then we want to
627 * make sure that it matches head.
629 if (index && !same(index, head)) {
635 if (same(head, remote))
636 return merged_entry(head, index);
638 if (!df_conflict_remote && remote_match && !head_match)
639 return merged_entry(head, index);
643 if (!head && !remote && any_anc_missing)
646 /* Under the new "aggressive" rule, we resolve mostly trivial
647 * cases that we historically had git-merge-one-file resolve.
650 int head_deleted = !head && !df_conflict_head;
651 int remote_deleted = !remote && !df_conflict_remote;
654 * Deleted in one and unchanged in the other.
656 if ((head_deleted && remote_deleted) ||
657 (head_deleted && remote && remote_match) ||
658 (remote_deleted && head && head_match)) {
660 return deleted_entry(index, index);
662 verify_absent(path, "removed");
666 * Added in both, identically.
668 if (no_anc_exists && head && remote && same(head, remote))
669 return merged_entry(head, index);
673 /* Below are "no merge" cases, which require that the index be
674 * up-to-date to avoid the files getting overwritten with
675 * conflict resolution files.
678 verify_uptodate(index);
681 verify_absent(path, "overwritten");
683 nontrivial_merge = 1;
685 /* #2, #3, #4, #6, #7, #9, #11. */
687 if (!head_match || !remote_match) {
688 for (i = 1; i < head_idx; i++) {
690 keep_entry(stages[i]);
698 fprintf(stderr, "read-tree: warning #16 detected\n");
699 show_stage_entry(stderr, "head ", stages[head_match]);
700 show_stage_entry(stderr, "remote ", stages[remote_match]);
703 if (head) { count += keep_entry(head); }
704 if (remote) { count += keep_entry(remote); }
711 * The rule is to "carry forward" what is in the index without losing
712 * information across a "fast forward", favoring a successful merge
713 * over a merge failure when it makes sense. For details of the
714 * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
717 static int twoway_merge(struct cache_entry **src)
719 struct cache_entry *current = src[0];
720 struct cache_entry *oldtree = src[1], *newtree = src[2];
723 return error("Cannot do a twoway merge of %d trees",
727 if ((!oldtree && !newtree) || /* 4 and 5 */
728 (!oldtree && newtree &&
729 same(current, newtree)) || /* 6 and 7 */
730 (oldtree && newtree &&
731 same(oldtree, newtree)) || /* 14 and 15 */
732 (oldtree && newtree &&
733 !same(oldtree, newtree) && /* 18 and 19*/
734 same(current, newtree))) {
735 return keep_entry(current);
737 else if (oldtree && !newtree && same(current, oldtree)) {
739 return deleted_entry(oldtree, current);
741 else if (oldtree && newtree &&
742 same(current, oldtree) && !same(current, newtree)) {
744 return merged_entry(newtree, current);
747 /* all other failures */
749 reject_merge(oldtree);
751 reject_merge(current);
753 reject_merge(newtree);
758 return merged_entry(newtree, current);
760 return deleted_entry(oldtree, current);
767 * - take the stat information from stage0, take the data from stage1
769 static int oneway_merge(struct cache_entry **src)
771 struct cache_entry *old = src[0];
772 struct cache_entry *a = src[1];
775 return error("Cannot do a oneway merge of %d trees",
779 return deleted_entry(old, old);
780 if (old && same(old, a)) {
783 if (lstat(old->name, &st) ||
784 ce_match_stat(old, &st, 1))
785 old->ce_flags |= htons(CE_UPDATE);
787 return keep_entry(old);
789 return merged_entry(a, old);
792 static int read_cache_unmerged(void)
795 struct cache_entry **dst;
800 for (i = 0; i < active_nr; i++) {
801 struct cache_entry *ce = active_cache[i];
804 invalidate_ce_path(ce);
811 active_nr -= deleted;
815 static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
817 struct tree_desc desc;
818 struct name_entry entry;
821 memcpy(it->sha1, tree->object.sha1, 20);
822 desc.buf = tree->buffer;
823 desc.size = tree->size;
825 while (tree_entry(&desc, &entry)) {
826 if (!S_ISDIR(entry.mode))
829 struct cache_tree_sub *sub;
830 struct tree *subtree = lookup_tree(entry.sha1);
831 if (!subtree->object.parsed)
833 sub = cache_tree_sub(it, entry.path);
834 sub->cache_tree = cache_tree();
835 prime_cache_tree_rec(sub->cache_tree, subtree);
836 cnt += sub->cache_tree->entry_count;
839 it->entry_count = cnt;
842 static void prime_cache_tree(void)
844 struct tree *tree = (struct tree *)trees->item;
847 active_cache_tree = cache_tree();
848 prime_cache_tree_rec(active_cache_tree, tree);
852 static const char read_tree_usage[] = "git-read-tree (<sha> | -m [--aggressive] [-u | -i] <sha1> [<sha2> [<sha3>]])";
854 static struct cache_file cache_file;
856 int cmd_read_tree(int argc, const char **argv, char **envp)
858 int i, newfd, stage = 0;
859 unsigned char sha1[20];
860 merge_fn_t fn = NULL;
862 setup_git_directory();
863 git_config(git_default_config);
865 newfd = hold_index_file_for_update(&cache_file, get_index_file());
867 die("unable to create new cachefile");
869 git_config(git_default_config);
873 for (i = 1; i < argc; i++) {
874 const char *arg = argv[i];
876 /* "-u" means "update", meaning that a merge will update
879 if (!strcmp(arg, "-u")) {
884 if (!strcmp(arg, "-v")) {
889 /* "-i" means "index only", meaning that a merge will
890 * not even look at the working tree.
892 if (!strcmp(arg, "-i")) {
897 /* This differs from "-m" in that we'll silently ignore unmerged entries */
898 if (!strcmp(arg, "--reset")) {
900 usage(read_tree_usage);
904 read_cache_unmerged();
908 if (!strcmp(arg, "--trivial")) {
909 trivial_merges_only = 1;
913 if (!strcmp(arg, "--aggressive")) {
918 /* "-m" stands for "merge", meaning we start in stage 1 */
919 if (!strcmp(arg, "-m")) {
921 usage(read_tree_usage);
922 if (read_cache_unmerged())
923 die("you need to resolve your current index first");
929 /* using -u and -i at the same time makes no sense */
930 if (1 < index_only + update)
931 usage(read_tree_usage);
933 if (get_sha1(arg, sha1))
934 die("Not a valid object name %s", arg);
935 if (list_tree(sha1) < 0)
936 die("failed to unpack tree object %s", arg);
939 if ((update||index_only) && !merge)
940 usage(read_tree_usage);
944 die("just how do you expect me to merge %d trees?", stage-1);
955 cache_tree_free(&active_cache_tree);
960 head_idx = stage - 2;
968 * When reading only one tree (either the most basic form,
969 * "-m ent" or "--reset ent" form), we can obtain a fully
970 * valid cache-tree because the index must match exactly
971 * what came from the tree.
973 if (trees && trees->item && (!merge || (stage == 2))) {
974 cache_tree_free(&active_cache_tree);
978 if (write_cache(newfd, active_cache, active_nr) ||
979 commit_index_file(&cache_file))
980 die("unable to write new index file");