зеркало из https://github.com/microsoft/git.git
731 строка
16 KiB
C
731 строка
16 KiB
C
/*
|
|
* GIT - The information manager from hell
|
|
*
|
|
* Copyright (C) Linus Torvalds, 2005
|
|
*/
|
|
#define DBRT_DEBUG 1
|
|
|
|
#include "cache.h"
|
|
|
|
#include "object.h"
|
|
#include "tree.h"
|
|
|
|
static int merge = 0;
|
|
static int update = 0;
|
|
static int index_only = 0;
|
|
static int nontrivial_merge = 0;
|
|
static int trivial_merges_only = 0;
|
|
|
|
static int head_idx = -1;
|
|
static int merge_size = 0;
|
|
|
|
static struct object_list *trees = NULL;
|
|
|
|
static struct cache_entry df_conflict_entry = {
|
|
};
|
|
|
|
static struct tree_entry_list df_conflict_list = {
|
|
.name = NULL,
|
|
.next = &df_conflict_list
|
|
};
|
|
|
|
typedef int (*merge_fn_t)(struct cache_entry **src);
|
|
|
|
static int entcmp(char *name1, int dir1, char *name2, int dir2)
|
|
{
|
|
int len1 = strlen(name1);
|
|
int len2 = strlen(name2);
|
|
int len = len1 < len2 ? len1 : len2;
|
|
int ret = memcmp(name1, name2, len);
|
|
unsigned char c1, c2;
|
|
if (ret)
|
|
return ret;
|
|
c1 = name1[len];
|
|
c2 = name2[len];
|
|
if (!c1 && dir1)
|
|
c1 = '/';
|
|
if (!c2 && dir2)
|
|
c2 = '/';
|
|
ret = (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0;
|
|
if (c1 && c2 && !ret)
|
|
ret = len1 - len2;
|
|
return ret;
|
|
}
|
|
|
|
static int unpack_trees_rec(struct tree_entry_list **posns, int len,
|
|
const char *base, merge_fn_t fn, int *indpos)
|
|
{
|
|
int baselen = strlen(base);
|
|
int src_size = len + 1;
|
|
do {
|
|
int i;
|
|
char *first;
|
|
int firstdir = 0;
|
|
int pathlen;
|
|
unsigned ce_size;
|
|
struct tree_entry_list **subposns;
|
|
struct cache_entry **src;
|
|
int any_files = 0;
|
|
int any_dirs = 0;
|
|
char *cache_name;
|
|
int ce_stage;
|
|
|
|
/* Find the first name in the input. */
|
|
|
|
first = NULL;
|
|
cache_name = NULL;
|
|
|
|
/* Check the cache */
|
|
if (merge && *indpos < active_nr) {
|
|
/* This is a bit tricky: */
|
|
/* If the index has a subdirectory (with
|
|
* contents) as the first name, it'll get a
|
|
* filename like "foo/bar". But that's after
|
|
* "foo", so the entry in trees will get
|
|
* handled first, at which point we'll go into
|
|
* "foo", and deal with "bar" from the index,
|
|
* because the base will be "foo/". The only
|
|
* way we can actually have "foo/bar" first of
|
|
* all the things is if the trees don't
|
|
* contain "foo" at all, in which case we'll
|
|
* handle "foo/bar" without going into the
|
|
* directory, but that's fine (and will return
|
|
* an error anyway, with the added unknown
|
|
* file case.
|
|
*/
|
|
|
|
cache_name = active_cache[*indpos]->name;
|
|
if (strlen(cache_name) > baselen &&
|
|
!memcmp(cache_name, base, baselen)) {
|
|
cache_name += baselen;
|
|
first = cache_name;
|
|
} else {
|
|
cache_name = NULL;
|
|
}
|
|
}
|
|
|
|
#if DBRT_DEBUG > 1
|
|
if (first)
|
|
printf("index %s\n", first);
|
|
#endif
|
|
for (i = 0; i < len; i++) {
|
|
if (!posns[i] || posns[i] == &df_conflict_list)
|
|
continue;
|
|
#if DBRT_DEBUG > 1
|
|
printf("%d %s\n", i + 1, posns[i]->name);
|
|
#endif
|
|
if (!first || entcmp(first, firstdir,
|
|
posns[i]->name,
|
|
posns[i]->directory) > 0) {
|
|
first = posns[i]->name;
|
|
firstdir = posns[i]->directory;
|
|
}
|
|
}
|
|
/* No name means we're done */
|
|
if (!first)
|
|
return 0;
|
|
|
|
pathlen = strlen(first);
|
|
ce_size = cache_entry_size(baselen + pathlen);
|
|
|
|
src = xmalloc(sizeof(struct cache_entry *) * src_size);
|
|
memset(src, 0, sizeof(struct cache_entry *) * src_size);
|
|
|
|
subposns = xmalloc(sizeof(struct tree_list_entry *) * len);
|
|
memset(subposns, 0, sizeof(struct tree_list_entry *) * len);
|
|
|
|
if (cache_name && !strcmp(cache_name, first)) {
|
|
any_files = 1;
|
|
src[0] = active_cache[*indpos];
|
|
remove_cache_entry_at(*indpos);
|
|
}
|
|
|
|
for (i = 0; i < len; i++) {
|
|
struct cache_entry *ce;
|
|
|
|
if (!posns[i] ||
|
|
(posns[i] != &df_conflict_list &&
|
|
strcmp(first, posns[i]->name))) {
|
|
continue;
|
|
}
|
|
|
|
if (posns[i] == &df_conflict_list) {
|
|
src[i + merge] = &df_conflict_entry;
|
|
continue;
|
|
}
|
|
|
|
if (posns[i]->directory) {
|
|
any_dirs = 1;
|
|
parse_tree(posns[i]->item.tree);
|
|
subposns[i] = posns[i]->item.tree->entries;
|
|
posns[i] = posns[i]->next;
|
|
src[i + merge] = &df_conflict_entry;
|
|
continue;
|
|
}
|
|
|
|
if (!merge)
|
|
ce_stage = 0;
|
|
else if (i + 1 < head_idx)
|
|
ce_stage = 1;
|
|
else if (i + 1 > head_idx)
|
|
ce_stage = 3;
|
|
else
|
|
ce_stage = 2;
|
|
|
|
ce = xmalloc(ce_size);
|
|
memset(ce, 0, ce_size);
|
|
ce->ce_mode = create_ce_mode(posns[i]->mode);
|
|
ce->ce_flags = create_ce_flags(baselen + pathlen,
|
|
ce_stage);
|
|
memcpy(ce->name, base, baselen);
|
|
memcpy(ce->name + baselen, first, pathlen + 1);
|
|
|
|
any_files = 1;
|
|
|
|
memcpy(ce->sha1, posns[i]->item.any->sha1, 20);
|
|
src[i + merge] = ce;
|
|
subposns[i] = &df_conflict_list;
|
|
posns[i] = posns[i]->next;
|
|
}
|
|
if (any_files) {
|
|
if (merge) {
|
|
int ret;
|
|
|
|
#if DBRT_DEBUG > 1
|
|
printf("%s:\n", first);
|
|
for (i = 0; i < src_size; i++) {
|
|
printf(" %d ", i);
|
|
if (src[i])
|
|
printf("%s\n", sha1_to_hex(src[i]->sha1));
|
|
else
|
|
printf("\n");
|
|
}
|
|
#endif
|
|
ret = fn(src);
|
|
|
|
#if DBRT_DEBUG > 1
|
|
printf("Added %d entries\n", ret);
|
|
#endif
|
|
*indpos += ret;
|
|
} else {
|
|
for (i = 0; i < src_size; i++) {
|
|
if (src[i]) {
|
|
add_cache_entry(src[i], ADD_CACHE_OK_TO_ADD|ADD_CACHE_SKIP_DFCHECK);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
if (any_dirs) {
|
|
char *newbase = xmalloc(baselen + 2 + pathlen);
|
|
memcpy(newbase, base, baselen);
|
|
memcpy(newbase + baselen, first, pathlen);
|
|
newbase[baselen + pathlen] = '/';
|
|
newbase[baselen + pathlen + 1] = '\0';
|
|
if (unpack_trees_rec(subposns, len, newbase, fn,
|
|
indpos))
|
|
return -1;
|
|
free(newbase);
|
|
}
|
|
free(subposns);
|
|
free(src);
|
|
} while (1);
|
|
}
|
|
|
|
static void reject_merge(struct cache_entry *ce)
|
|
{
|
|
die("Entry '%s' would be overwritten by merge. Cannot merge.",
|
|
ce->name);
|
|
}
|
|
|
|
/* Unlink the last component and attempt to remove leading
|
|
* directories, in case this unlink is the removal of the
|
|
* last entry in the directory -- empty directories are removed.
|
|
*/
|
|
static void unlink_entry(char *name)
|
|
{
|
|
char *cp, *prev;
|
|
|
|
if (unlink(name))
|
|
return;
|
|
prev = NULL;
|
|
while (1) {
|
|
int status;
|
|
cp = strrchr(name, '/');
|
|
if (prev)
|
|
*prev = '/';
|
|
if (!cp)
|
|
break;
|
|
|
|
*cp = 0;
|
|
status = rmdir(name);
|
|
if (status) {
|
|
*cp = '/';
|
|
break;
|
|
}
|
|
prev = cp;
|
|
}
|
|
}
|
|
|
|
static void check_updates(struct cache_entry **src, int nr)
|
|
{
|
|
static struct checkout state = {
|
|
.base_dir = "",
|
|
.force = 1,
|
|
.quiet = 1,
|
|
.refresh_cache = 1,
|
|
};
|
|
unsigned short mask = htons(CE_UPDATE);
|
|
while (nr--) {
|
|
struct cache_entry *ce = *src++;
|
|
if (!ce->ce_mode) {
|
|
if (update)
|
|
unlink_entry(ce->name);
|
|
continue;
|
|
}
|
|
if (ce->ce_flags & mask) {
|
|
ce->ce_flags &= ~mask;
|
|
if (update)
|
|
checkout_entry(ce, &state);
|
|
}
|
|
}
|
|
}
|
|
|
|
static int unpack_trees(merge_fn_t fn)
|
|
{
|
|
int indpos = 0;
|
|
unsigned len = object_list_length(trees);
|
|
struct tree_entry_list **posns =
|
|
xmalloc(len * sizeof(struct tree_entry_list *));
|
|
int i;
|
|
struct object_list *posn = trees;
|
|
merge_size = len;
|
|
for (i = 0; i < len; i++) {
|
|
posns[i] = ((struct tree *) posn->item)->entries;
|
|
posn = posn->next;
|
|
}
|
|
if (unpack_trees_rec(posns, len, "", fn, &indpos))
|
|
return -1;
|
|
|
|
if (trivial_merges_only && nontrivial_merge)
|
|
die("Merge requires file-level merging");
|
|
|
|
check_updates(active_cache, active_nr);
|
|
return 0;
|
|
}
|
|
|
|
static int list_tree(unsigned char *sha1)
|
|
{
|
|
struct tree *tree = parse_tree_indirect(sha1);
|
|
if (!tree)
|
|
return -1;
|
|
object_list_append(&tree->object, &trees);
|
|
return 0;
|
|
}
|
|
|
|
static int same(struct cache_entry *a, struct cache_entry *b)
|
|
{
|
|
if (!!a != !!b)
|
|
return 0;
|
|
if (!a && !b)
|
|
return 1;
|
|
return a->ce_mode == b->ce_mode &&
|
|
!memcmp(a->sha1, b->sha1, 20);
|
|
}
|
|
|
|
|
|
/*
|
|
* When a CE gets turned into an unmerged entry, we
|
|
* want it to be up-to-date
|
|
*/
|
|
static void verify_uptodate(struct cache_entry *ce)
|
|
{
|
|
struct stat st;
|
|
|
|
if (index_only)
|
|
return;
|
|
|
|
if (!lstat(ce->name, &st)) {
|
|
unsigned changed = ce_match_stat(ce, &st);
|
|
if (!changed)
|
|
return;
|
|
errno = 0;
|
|
}
|
|
if (errno == ENOENT)
|
|
return;
|
|
die("Entry '%s' not uptodate. Cannot merge.", ce->name);
|
|
}
|
|
|
|
static int merged_entry(struct cache_entry *merge, struct cache_entry *old)
|
|
{
|
|
merge->ce_flags |= htons(CE_UPDATE);
|
|
if (old) {
|
|
/*
|
|
* See if we can re-use the old CE directly?
|
|
* That way we get the uptodate stat info.
|
|
*
|
|
* This also removes the UPDATE flag on
|
|
* a match.
|
|
*/
|
|
if (same(old, merge)) {
|
|
*merge = *old;
|
|
} else {
|
|
verify_uptodate(old);
|
|
}
|
|
}
|
|
merge->ce_flags &= ~htons(CE_STAGEMASK);
|
|
add_cache_entry(merge, ADD_CACHE_OK_TO_ADD);
|
|
return 1;
|
|
}
|
|
|
|
static int deleted_entry(struct cache_entry *ce, struct cache_entry *old)
|
|
{
|
|
if (old)
|
|
verify_uptodate(old);
|
|
ce->ce_mode = 0;
|
|
add_cache_entry(ce, ADD_CACHE_OK_TO_ADD);
|
|
return 1;
|
|
}
|
|
|
|
static int keep_entry(struct cache_entry *ce)
|
|
{
|
|
add_cache_entry(ce, ADD_CACHE_OK_TO_ADD);
|
|
return 1;
|
|
}
|
|
|
|
#if DBRT_DEBUG
|
|
static void show_stage_entry(FILE *o,
|
|
const char *label, const struct cache_entry *ce)
|
|
{
|
|
if (!ce)
|
|
fprintf(o, "%s (missing)\n", label);
|
|
else
|
|
fprintf(o, "%s%06o %s %d\t%s\n",
|
|
label,
|
|
ntohl(ce->ce_mode),
|
|
sha1_to_hex(ce->sha1),
|
|
ce_stage(ce),
|
|
ce->name);
|
|
}
|
|
#endif
|
|
|
|
static int threeway_merge(struct cache_entry **stages)
|
|
{
|
|
struct cache_entry *index;
|
|
struct cache_entry *head;
|
|
struct cache_entry *remote = stages[head_idx + 1];
|
|
int count;
|
|
int head_match = 0;
|
|
int remote_match = 0;
|
|
|
|
int df_conflict_head = 0;
|
|
int df_conflict_remote = 0;
|
|
|
|
int any_anc_missing = 0;
|
|
int i;
|
|
|
|
for (i = 1; i < head_idx; i++) {
|
|
if (!stages[i])
|
|
any_anc_missing = 1;
|
|
}
|
|
|
|
index = stages[0];
|
|
head = stages[head_idx];
|
|
|
|
if (head == &df_conflict_entry) {
|
|
df_conflict_head = 1;
|
|
head = NULL;
|
|
}
|
|
|
|
if (remote == &df_conflict_entry) {
|
|
df_conflict_remote = 1;
|
|
remote = NULL;
|
|
}
|
|
|
|
/* First, if there's a #16 situation, note that to prevent #13
|
|
* and #14.
|
|
*/
|
|
if (!same(remote, head)) {
|
|
for (i = 1; i < head_idx; i++) {
|
|
if (same(stages[i], head)) {
|
|
head_match = i;
|
|
}
|
|
if (same(stages[i], remote)) {
|
|
remote_match = i;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* We start with cases where the index is allowed to match
|
|
* something other than the head: #14(ALT) and #2ALT, where it
|
|
* is permitted to match the result instead.
|
|
*/
|
|
/* #14, #14ALT, #2ALT */
|
|
if (remote && !df_conflict_head && head_match && !remote_match) {
|
|
if (index && !same(index, remote) && !same(index, head))
|
|
reject_merge(index);
|
|
return merged_entry(remote, index);
|
|
}
|
|
/*
|
|
* If we have an entry in the index cache, then we want to
|
|
* make sure that it matches head.
|
|
*/
|
|
if (index && !same(index, head)) {
|
|
reject_merge(index);
|
|
}
|
|
|
|
if (head) {
|
|
/* #5ALT, #15 */
|
|
if (same(head, remote))
|
|
return merged_entry(head, index);
|
|
/* #13, #3ALT */
|
|
if (!df_conflict_remote && remote_match && !head_match)
|
|
return merged_entry(head, index);
|
|
}
|
|
|
|
/* #1 */
|
|
if (!head && !remote && any_anc_missing)
|
|
return 0;
|
|
|
|
/* Below are "no merge" cases, which require that the index be
|
|
* up-to-date to avoid the files getting overwritten with
|
|
* conflict resolution files.
|
|
*/
|
|
if (index) {
|
|
verify_uptodate(index);
|
|
}
|
|
|
|
nontrivial_merge = 1;
|
|
|
|
/* #2, #3, #4, #6, #7, #9, #11. */
|
|
count = 0;
|
|
if (!head_match || !remote_match) {
|
|
for (i = 1; i < head_idx; i++) {
|
|
if (stages[i]) {
|
|
keep_entry(stages[i]);
|
|
count++;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
#if DBRT_DEBUG
|
|
else {
|
|
fprintf(stderr, "read-tree: warning #16 detected\n");
|
|
show_stage_entry(stderr, "head ", stages[head_match]);
|
|
show_stage_entry(stderr, "remote ", stages[remote_match]);
|
|
}
|
|
#endif
|
|
if (head) { count += keep_entry(head); }
|
|
if (remote) { count += keep_entry(remote); }
|
|
return count;
|
|
}
|
|
|
|
/*
|
|
* Two-way merge.
|
|
*
|
|
* The rule is to "carry forward" what is in the index without losing
|
|
* information across a "fast forward", favoring a successful merge
|
|
* over a merge failure when it makes sense. For details of the
|
|
* "carry forward" rule, please see <Documentation/git-read-tree.txt>.
|
|
*
|
|
*/
|
|
static int twoway_merge(struct cache_entry **src)
|
|
{
|
|
struct cache_entry *current = src[0];
|
|
struct cache_entry *oldtree = src[1], *newtree = src[2];
|
|
|
|
if (merge_size != 2)
|
|
return error("Cannot do a twoway merge of %d trees\n",
|
|
merge_size);
|
|
|
|
if (current) {
|
|
if ((!oldtree && !newtree) || /* 4 and 5 */
|
|
(!oldtree && newtree &&
|
|
same(current, newtree)) || /* 6 and 7 */
|
|
(oldtree && newtree &&
|
|
same(oldtree, newtree)) || /* 14 and 15 */
|
|
(oldtree && newtree &&
|
|
!same(oldtree, newtree) && /* 18 and 19*/
|
|
same(current, newtree))) {
|
|
return keep_entry(current);
|
|
}
|
|
else if (oldtree && !newtree && same(current, oldtree)) {
|
|
/* 10 or 11 */
|
|
return deleted_entry(oldtree, current);
|
|
}
|
|
else if (oldtree && newtree &&
|
|
same(current, oldtree) && !same(current, newtree)) {
|
|
/* 20 or 21 */
|
|
return merged_entry(newtree, current);
|
|
}
|
|
else {
|
|
/* all other failures */
|
|
if (oldtree)
|
|
reject_merge(oldtree);
|
|
if (current)
|
|
reject_merge(current);
|
|
if (newtree)
|
|
reject_merge(newtree);
|
|
return -1;
|
|
}
|
|
}
|
|
else if (newtree)
|
|
return merged_entry(newtree, current);
|
|
else
|
|
return deleted_entry(oldtree, current);
|
|
}
|
|
|
|
/*
|
|
* One-way merge.
|
|
*
|
|
* The rule is:
|
|
* - take the stat information from stage0, take the data from stage1
|
|
*/
|
|
static int oneway_merge(struct cache_entry **src)
|
|
{
|
|
struct cache_entry *old = src[0];
|
|
struct cache_entry *a = src[1];
|
|
|
|
if (merge_size != 1)
|
|
return error("Cannot do a oneway merge of %d trees\n",
|
|
merge_size);
|
|
|
|
if (!a)
|
|
return 0;
|
|
if (old && same(old, a)) {
|
|
return keep_entry(old);
|
|
}
|
|
return merged_entry(a, NULL);
|
|
}
|
|
|
|
static int read_cache_unmerged(void)
|
|
{
|
|
int i, deleted;
|
|
struct cache_entry **dst;
|
|
|
|
read_cache();
|
|
dst = active_cache;
|
|
deleted = 0;
|
|
for (i = 0; i < active_nr; i++) {
|
|
struct cache_entry *ce = active_cache[i];
|
|
if (ce_stage(ce)) {
|
|
deleted++;
|
|
continue;
|
|
}
|
|
if (deleted)
|
|
*dst = ce;
|
|
dst++;
|
|
}
|
|
active_nr -= deleted;
|
|
return deleted;
|
|
}
|
|
|
|
static const char read_tree_usage[] = "git-read-tree (<sha> | -m [-u | -i] <sha1> [<sha2> [<sha3>]])";
|
|
|
|
static struct cache_file cache_file;
|
|
|
|
int main(int argc, char **argv)
|
|
{
|
|
int i, newfd, reset, stage = 0;
|
|
unsigned char sha1[20];
|
|
merge_fn_t fn = NULL;
|
|
|
|
setup_git_directory();
|
|
|
|
newfd = hold_index_file_for_update(&cache_file, get_index_file());
|
|
if (newfd < 0)
|
|
die("unable to create new cachefile");
|
|
|
|
git_config(git_default_config);
|
|
|
|
merge = 0;
|
|
reset = 0;
|
|
for (i = 1; i < argc; i++) {
|
|
const char *arg = argv[i];
|
|
|
|
/* "-u" means "update", meaning that a merge will update
|
|
* the working tree.
|
|
*/
|
|
if (!strcmp(arg, "-u")) {
|
|
update = 1;
|
|
continue;
|
|
}
|
|
|
|
/* "-i" means "index only", meaning that a merge will
|
|
* not even look at the working tree.
|
|
*/
|
|
if (!strcmp(arg, "-i")) {
|
|
index_only = 1;
|
|
continue;
|
|
}
|
|
|
|
/* This differs from "-m" in that we'll silently ignore unmerged entries */
|
|
if (!strcmp(arg, "--reset")) {
|
|
if (stage || merge)
|
|
usage(read_tree_usage);
|
|
reset = 1;
|
|
merge = 1;
|
|
stage = 1;
|
|
read_cache_unmerged();
|
|
continue;
|
|
}
|
|
|
|
if (!strcmp(arg, "--trivial")) {
|
|
trivial_merges_only = 1;
|
|
continue;
|
|
}
|
|
|
|
/* "-m" stands for "merge", meaning we start in stage 1 */
|
|
if (!strcmp(arg, "-m")) {
|
|
if (stage || merge)
|
|
usage(read_tree_usage);
|
|
if (read_cache_unmerged())
|
|
die("you need to resolve your current index first");
|
|
stage = 1;
|
|
merge = 1;
|
|
continue;
|
|
}
|
|
|
|
/* using -u and -i at the same time makes no sense */
|
|
if (1 < index_only + update)
|
|
usage(read_tree_usage);
|
|
|
|
if (get_sha1(arg, sha1) < 0)
|
|
usage(read_tree_usage);
|
|
if (list_tree(sha1) < 0)
|
|
die("failed to unpack tree object %s", arg);
|
|
stage++;
|
|
}
|
|
if ((update||index_only) && !merge)
|
|
usage(read_tree_usage);
|
|
|
|
if (merge) {
|
|
if (stage < 2)
|
|
die("just how do you expect me to merge %d trees?", stage-1);
|
|
switch (stage - 1) {
|
|
case 1:
|
|
fn = oneway_merge;
|
|
break;
|
|
case 2:
|
|
fn = twoway_merge;
|
|
break;
|
|
case 3:
|
|
fn = threeway_merge;
|
|
break;
|
|
default:
|
|
fn = threeway_merge;
|
|
break;
|
|
}
|
|
|
|
if (stage - 1 >= 3)
|
|
head_idx = stage - 2;
|
|
else
|
|
head_idx = 1;
|
|
}
|
|
|
|
unpack_trees(fn);
|
|
if (write_cache(newfd, active_cache, active_nr) ||
|
|
commit_index_file(&cache_file))
|
|
die("unable to write new index file");
|
|
return 0;
|
|
}
|