2 * GIT - The information manager from hell
4 * Copyright (C) Linus Torvalds, 2005
16 static int update
= 0;
17 static int index_only
= 0;
18 static int nontrivial_merge
= 0;
19 static int trivial_merges_only
= 0;
20 static int aggressive
= 0;
21 static int verbose_update
= 0;
22 static volatile int progress_update
= 0;
24 static int head_idx
= -1;
25 static int merge_size
= 0;
27 static struct object_list
*trees
= NULL
;
29 static struct cache_entry df_conflict_entry
= {
32 static struct tree_entry_list df_conflict_list
= {
34 .next
= &df_conflict_list
37 typedef int (*merge_fn_t
)(struct cache_entry
**src
);
39 static int entcmp(char *name1
, int dir1
, char *name2
, int dir2
)
41 int len1
= strlen(name1
);
42 int len2
= strlen(name2
);
43 int len
= len1
< len2
? len1
: len2
;
44 int ret
= memcmp(name1
, name2
, len
);
54 ret
= (c1
< c2
) ? -1 : (c1
> c2
) ? 1 : 0;
60 static int unpack_trees_rec(struct tree_entry_list
**posns
, int len
,
61 const char *base
, merge_fn_t fn
, int *indpos
)
63 int baselen
= strlen(base
);
64 int src_size
= len
+ 1;
71 struct tree_entry_list
**subposns
;
72 struct cache_entry
**src
;
78 /* Find the first name in the input. */
84 if (merge
&& *indpos
< active_nr
) {
85 /* This is a bit tricky: */
86 /* If the index has a subdirectory (with
87 * contents) as the first name, it'll get a
88 * filename like "foo/bar". But that's after
89 * "foo", so the entry in trees will get
90 * handled first, at which point we'll go into
91 * "foo", and deal with "bar" from the index,
92 * because the base will be "foo/". The only
93 * way we can actually have "foo/bar" first of
94 * all the things is if the trees don't
95 * contain "foo" at all, in which case we'll
96 * handle "foo/bar" without going into the
97 * directory, but that's fine (and will return
98 * an error anyway, with the added unknown
102 cache_name
= active_cache
[*indpos
]->name
;
103 if (strlen(cache_name
) > baselen
&&
104 !memcmp(cache_name
, base
, baselen
)) {
105 cache_name
+= baselen
;
114 printf("index %s\n", first
);
116 for (i
= 0; i
< len
; i
++) {
117 if (!posns
[i
] || posns
[i
] == &df_conflict_list
)
120 printf("%d %s\n", i
+ 1, posns
[i
]->name
);
122 if (!first
|| entcmp(first
, firstdir
,
124 posns
[i
]->directory
) > 0) {
125 first
= posns
[i
]->name
;
126 firstdir
= posns
[i
]->directory
;
129 /* No name means we're done */
133 pathlen
= strlen(first
);
134 ce_size
= cache_entry_size(baselen
+ pathlen
);
136 src
= xmalloc(sizeof(struct cache_entry
*) * src_size
);
137 memset(src
, 0, sizeof(struct cache_entry
*) * src_size
);
139 subposns
= xmalloc(sizeof(struct tree_list_entry
*) * len
);
140 memset(subposns
, 0, sizeof(struct tree_list_entry
*) * len
);
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
) {
164 parse_tree(posns
[i
]->item
.tree
);
165 subposns
[i
] = posns
[i
]->item
.tree
->entries
;
166 posns
[i
] = posns
[i
]->next
;
167 src
[i
+ merge
] = &df_conflict_entry
;
173 else if (i
+ 1 < head_idx
)
175 else if (i
+ 1 > head_idx
)
180 ce
= xmalloc(ce_size
);
181 memset(ce
, 0, 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
]->item
.any
->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
)
276 signal(SIGALRM
, progress_interval
);
280 static void check_updates(struct cache_entry
**src
, int nr
)
282 static struct checkout state
= {
288 unsigned short mask
= htons(CE_UPDATE
);
289 unsigned last_percent
= 200, cnt
= 0, total
= 0;
291 if (update
&& verbose_update
) {
294 for (total
= cnt
= 0; cnt
< nr
; cnt
++) {
295 struct cache_entry
*ce
= src
[cnt
];
296 if (!ce
->ce_mode
|| ce
->ce_flags
& mask
)
300 /* Don't bother doing this for very small updates */
305 v
.it_interval
.tv_sec
= 1;
306 v
.it_interval
.tv_usec
= 0;
307 v
.it_value
= v
.it_interval
;
308 signal(SIGALRM
, progress_interval
);
309 setitimer(ITIMER_REAL
, &v
, NULL
);
310 fprintf(stderr
, "Checking files out...\n");
317 struct cache_entry
*ce
= *src
++;
320 if (!ce
->ce_mode
|| ce
->ce_flags
& mask
) {
323 percent
= (cnt
* 100) / total
;
324 if (percent
!= last_percent
||
326 fprintf(stderr
, "%4u%% (%u/%u) done\r",
327 percent
, cnt
, total
);
328 last_percent
= percent
;
334 unlink_entry(ce
->name
);
337 if (ce
->ce_flags
& mask
) {
338 ce
->ce_flags
&= ~mask
;
340 checkout_entry(ce
, &state
);
345 signal(SIGALRM
, SIG_IGN
);
349 static int unpack_trees(merge_fn_t fn
)
352 unsigned len
= object_list_length(trees
);
353 struct tree_entry_list
**posns
;
355 struct object_list
*posn
= trees
;
359 posns
= xmalloc(len
* sizeof(struct tree_entry_list
*));
360 for (i
= 0; i
< len
; i
++) {
361 posns
[i
] = ((struct tree
*) posn
->item
)->entries
;
364 if (unpack_trees_rec(posns
, len
, "", fn
, &indpos
))
368 if (trivial_merges_only
&& nontrivial_merge
)
369 die("Merge requires file-level merging");
371 check_updates(active_cache
, active_nr
);
375 static int list_tree(unsigned char *sha1
)
377 struct tree
*tree
= parse_tree_indirect(sha1
);
380 object_list_append(&tree
->object
, &trees
);
384 static int same(struct cache_entry
*a
, struct cache_entry
*b
)
390 return a
->ce_mode
== b
->ce_mode
&&
391 !memcmp(a
->sha1
, b
->sha1
, 20);
396 * When a CE gets turned into an unmerged entry, we
397 * want it to be up-to-date
399 static void verify_uptodate(struct cache_entry
*ce
)
406 if (!lstat(ce
->name
, &st
)) {
407 unsigned changed
= ce_match_stat(ce
, &st
);
414 die("Entry '%s' not uptodate. Cannot merge.", ce
->name
);
417 static int merged_entry(struct cache_entry
*merge
, struct cache_entry
*old
)
419 merge
->ce_flags
|= htons(CE_UPDATE
);
422 * See if we can re-use the old CE directly?
423 * That way we get the uptodate stat info.
425 * This also removes the UPDATE flag on
428 if (same(old
, merge
)) {
431 verify_uptodate(old
);
434 merge
->ce_flags
&= ~htons(CE_STAGEMASK
);
435 add_cache_entry(merge
, ADD_CACHE_OK_TO_ADD
);
439 static int deleted_entry(struct cache_entry
*ce
, struct cache_entry
*old
)
442 verify_uptodate(old
);
444 add_cache_entry(ce
, ADD_CACHE_OK_TO_ADD
);
448 static int keep_entry(struct cache_entry
*ce
)
450 add_cache_entry(ce
, ADD_CACHE_OK_TO_ADD
);
455 static void show_stage_entry(FILE *o
,
456 const char *label
, const struct cache_entry
*ce
)
459 fprintf(o
, "%s (missing)\n", label
);
461 fprintf(o
, "%s%06o %s %d\t%s\n",
464 sha1_to_hex(ce
->sha1
),
470 static int threeway_merge(struct cache_entry
**stages
)
472 struct cache_entry
*index
;
473 struct cache_entry
*head
;
474 struct cache_entry
*remote
= stages
[head_idx
+ 1];
477 int remote_match
= 0;
479 int df_conflict_head
= 0;
480 int df_conflict_remote
= 0;
482 int any_anc_missing
= 0;
483 int no_anc_exists
= 1;
486 for (i
= 1; i
< head_idx
; i
++) {
494 head
= stages
[head_idx
];
496 if (head
== &df_conflict_entry
) {
497 df_conflict_head
= 1;
501 if (remote
== &df_conflict_entry
) {
502 df_conflict_remote
= 1;
506 /* First, if there's a #16 situation, note that to prevent #13
509 if (!same(remote
, head
)) {
510 for (i
= 1; i
< head_idx
; i
++) {
511 if (same(stages
[i
], head
)) {
514 if (same(stages
[i
], remote
)) {
520 /* We start with cases where the index is allowed to match
521 * something other than the head: #14(ALT) and #2ALT, where it
522 * is permitted to match the result instead.
524 /* #14, #14ALT, #2ALT */
525 if (remote
&& !df_conflict_head
&& head_match
&& !remote_match
) {
526 if (index
&& !same(index
, remote
) && !same(index
, head
))
528 return merged_entry(remote
, index
);
531 * If we have an entry in the index cache, then we want to
532 * make sure that it matches head.
534 if (index
&& !same(index
, head
)) {
540 if (same(head
, remote
))
541 return merged_entry(head
, index
);
543 if (!df_conflict_remote
&& remote_match
&& !head_match
)
544 return merged_entry(head
, index
);
548 if (!head
&& !remote
&& any_anc_missing
)
551 /* Under the new "aggressive" rule, we resolve mostly trivial
552 * cases that we historically had git-merge-one-file resolve.
555 int head_deleted
= !head
&& !df_conflict_head
;
556 int remote_deleted
= !remote
&& !df_conflict_remote
;
559 * Deleted in one and unchanged in the other.
561 if ((head_deleted
&& remote_deleted
) ||
562 (head_deleted
&& remote
&& remote_match
) ||
563 (remote_deleted
&& head
&& head_match
))
567 * Added in both, identically.
569 if (no_anc_exists
&& head
&& remote
&& same(head
, remote
))
570 return merged_entry(head
, index
);
574 /* Below are "no merge" cases, which require that the index be
575 * up-to-date to avoid the files getting overwritten with
576 * conflict resolution files.
579 verify_uptodate(index
);
582 nontrivial_merge
= 1;
584 /* #2, #3, #4, #6, #7, #9, #11. */
586 if (!head_match
|| !remote_match
) {
587 for (i
= 1; i
< head_idx
; i
++) {
589 keep_entry(stages
[i
]);
597 fprintf(stderr
, "read-tree: warning #16 detected\n");
598 show_stage_entry(stderr
, "head ", stages
[head_match
]);
599 show_stage_entry(stderr
, "remote ", stages
[remote_match
]);
602 if (head
) { count
+= keep_entry(head
); }
603 if (remote
) { count
+= keep_entry(remote
); }
610 * The rule is to "carry forward" what is in the index without losing
611 * information across a "fast forward", favoring a successful merge
612 * over a merge failure when it makes sense. For details of the
613 * "carry forward" rule, please see <Documentation/git-read-tree.txt>.
616 static int twoway_merge(struct cache_entry
**src
)
618 struct cache_entry
*current
= src
[0];
619 struct cache_entry
*oldtree
= src
[1], *newtree
= src
[2];
622 return error("Cannot do a twoway merge of %d trees\n",
626 if ((!oldtree
&& !newtree
) || /* 4 and 5 */
627 (!oldtree
&& newtree
&&
628 same(current
, newtree
)) || /* 6 and 7 */
629 (oldtree
&& newtree
&&
630 same(oldtree
, newtree
)) || /* 14 and 15 */
631 (oldtree
&& newtree
&&
632 !same(oldtree
, newtree
) && /* 18 and 19*/
633 same(current
, newtree
))) {
634 return keep_entry(current
);
636 else if (oldtree
&& !newtree
&& same(current
, oldtree
)) {
638 return deleted_entry(oldtree
, current
);
640 else if (oldtree
&& newtree
&&
641 same(current
, oldtree
) && !same(current
, newtree
)) {
643 return merged_entry(newtree
, current
);
646 /* all other failures */
648 reject_merge(oldtree
);
650 reject_merge(current
);
652 reject_merge(newtree
);
657 return merged_entry(newtree
, current
);
659 return deleted_entry(oldtree
, current
);
666 * - take the stat information from stage0, take the data from stage1
668 static int oneway_merge(struct cache_entry
**src
)
670 struct cache_entry
*old
= src
[0];
671 struct cache_entry
*a
= src
[1];
674 return error("Cannot do a oneway merge of %d trees\n",
679 if (old
&& same(old
, a
)) {
680 return keep_entry(old
);
682 return merged_entry(a
, NULL
);
685 static int read_cache_unmerged(void)
688 struct cache_entry
**dst
;
693 for (i
= 0; i
< active_nr
; i
++) {
694 struct cache_entry
*ce
= active_cache
[i
];
703 active_nr
-= deleted
;
707 static const char read_tree_usage
[] = "git-read-tree (<sha> | -m [-u | -i] <sha1> [<sha2> [<sha3>]])";
709 static struct cache_file cache_file
;
711 int main(int argc
, char **argv
)
713 int i
, newfd
, reset
, stage
= 0;
714 unsigned char sha1
[20];
715 merge_fn_t fn
= NULL
;
717 setup_git_directory();
719 newfd
= hold_index_file_for_update(&cache_file
, get_index_file());
721 die("unable to create new cachefile");
723 git_config(git_default_config
);
727 for (i
= 1; i
< argc
; i
++) {
728 const char *arg
= argv
[i
];
730 /* "-u" means "update", meaning that a merge will update
733 if (!strcmp(arg
, "-u")) {
738 if (!strcmp(arg
, "-v")) {
743 /* "-i" means "index only", meaning that a merge will
744 * not even look at the working tree.
746 if (!strcmp(arg
, "-i")) {
751 /* This differs from "-m" in that we'll silently ignore unmerged entries */
752 if (!strcmp(arg
, "--reset")) {
754 usage(read_tree_usage
);
758 read_cache_unmerged();
762 if (!strcmp(arg
, "--trivial")) {
763 trivial_merges_only
= 1;
767 if (!strcmp(arg
, "--aggressive")) {
772 /* "-m" stands for "merge", meaning we start in stage 1 */
773 if (!strcmp(arg
, "-m")) {
775 usage(read_tree_usage
);
776 if (read_cache_unmerged())
777 die("you need to resolve your current index first");
783 /* using -u and -i at the same time makes no sense */
784 if (1 < index_only
+ update
)
785 usage(read_tree_usage
);
787 if (get_sha1(arg
, sha1
) < 0)
788 usage(read_tree_usage
);
789 if (list_tree(sha1
) < 0)
790 die("failed to unpack tree object %s", arg
);
793 if ((update
||index_only
) && !merge
)
794 usage(read_tree_usage
);
798 die("just how do you expect me to merge %d trees?", stage
-1);
815 head_idx
= stage
- 2;
821 if (write_cache(newfd
, active_cache
, active_nr
) ||
822 commit_index_file(&cache_file
))
823 die("unable to write new index file");