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
] = tree
->entries
;
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
] = ((struct tree
*) posn
->item
)->entries
;
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");