Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
Fetching contributors…

Cannot retrieve contributors at this time

359 lines (307 sloc) 8.194 kb
#include "builtin.h"
#include "tree-walk.h"
#include "xdiff-interface.h"
#include "blob.h"
#include "exec_cmd.h"
#include "merge-file.h"
static const char merge_tree_usage[] = "git merge-tree <base-tree> <branch1> <branch2>";
static int resolve_directories = 1;
struct merge_list {
struct merge_list *next;
struct merge_list *link; /* other stages for this object */
unsigned int stage : 2,
flags : 30;
unsigned int mode;
const char *path;
struct blob *blob;
};
static struct merge_list *merge_result, **merge_result_end = &merge_result;
static void add_merge_entry(struct merge_list *entry)
{
*merge_result_end = entry;
merge_result_end = &entry->next;
}
static void merge_trees(struct tree_desc t[3], const char *base);
static const char *explanation(struct merge_list *entry)
{
switch (entry->stage) {
case 0:
return "merged";
case 3:
return "added in remote";
case 2:
if (entry->link)
return "added in both";
return "added in local";
}
/* Existed in base */
entry = entry->link;
if (!entry)
return "removed in both";
if (entry->link)
return "changed in both";
if (entry->stage == 3)
return "removed in local";
return "removed in remote";
}
static void *result(struct merge_list *entry, unsigned long *size)
{
enum object_type type;
struct blob *base, *our, *their;
const char *path = entry->path;
if (!entry->stage)
return read_sha1_file(entry->blob->object.sha1, &type, size);
base = NULL;
if (entry->stage == 1) {
base = entry->blob;
entry = entry->link;
}
our = NULL;
if (entry && entry->stage == 2) {
our = entry->blob;
entry = entry->link;
}
their = NULL;
if (entry)
their = entry->blob;
return merge_file(path, base, our, their, size);
}
static void *origin(struct merge_list *entry, unsigned long *size)
{
enum object_type type;
while (entry) {
if (entry->stage == 2)
return read_sha1_file(entry->blob->object.sha1, &type, size);
entry = entry->link;
}
return NULL;
}
static int show_outf(void *priv_, mmbuffer_t *mb, int nbuf)
{
int i;
for (i = 0; i < nbuf; i++)
printf("%.*s", (int) mb[i].size, mb[i].ptr);
return 0;
}
static void show_diff(struct merge_list *entry)
{
unsigned long size;
mmfile_t src, dst;
xpparam_t xpp;
xdemitconf_t xecfg;
xdemitcb_t ecb;
xpp.flags = 0;
memset(&xecfg, 0, sizeof(xecfg));
xecfg.ctxlen = 3;
ecb.outf = show_outf;
ecb.priv = NULL;
src.ptr = origin(entry, &size);
if (!src.ptr)
size = 0;
src.size = size;
dst.ptr = result(entry, &size);
if (!dst.ptr)
size = 0;
dst.size = size;
xdi_diff(&src, &dst, &xpp, &xecfg, &ecb);
free(src.ptr);
free(dst.ptr);
}
static void show_result_list(struct merge_list *entry)
{
printf("%s\n", explanation(entry));
do {
struct merge_list *link = entry->link;
static const char *desc[4] = { "result", "base", "our", "their" };
printf(" %-6s %o %s %s\n", desc[entry->stage], entry->mode, sha1_to_hex(entry->blob->object.sha1), entry->path);
entry = link;
} while (entry);
}
static void show_result(void)
{
struct merge_list *walk;
walk = merge_result;
while (walk) {
show_result_list(walk);
show_diff(walk);
walk = walk->next;
}
}
/* An empty entry never compares same, not even to another empty entry */
static int same_entry(struct name_entry *a, struct name_entry *b)
{
return a->sha1 &&
b->sha1 &&
!hashcmp(a->sha1, b->sha1) &&
a->mode == b->mode;
}
static struct merge_list *create_entry(unsigned stage, unsigned mode, const unsigned char *sha1, const char *path)
{
struct merge_list *res = xcalloc(1, sizeof(*res));
res->stage = stage;
res->path = path;
res->mode = mode;
res->blob = lookup_blob(sha1);
return res;
}
static char *traverse_path(const struct traverse_info *info, const struct name_entry *n)
{
char *path = xmalloc(traverse_path_len(info, n) + 1);
return make_traverse_path(path, info, n);
}
static void resolve(const struct traverse_info *info, struct name_entry *branch1, struct name_entry *result)
{
struct merge_list *orig, *final;
const char *path;
/* If it's already branch1, don't bother showing it */
if (!branch1)
return;
path = traverse_path(info, result);
orig = create_entry(2, branch1->mode, branch1->sha1, path);
final = create_entry(0, result->mode, result->sha1, path);
final->link = orig;
add_merge_entry(final);
}
static int unresolved_directory(const struct traverse_info *info, struct name_entry n[3])
{
char *newbase;
struct name_entry *p;
struct tree_desc t[3];
void *buf0, *buf1, *buf2;
if (!resolve_directories)
return 0;
p = n;
if (!p->mode) {
p++;
if (!p->mode)
p++;
}
if (!S_ISDIR(p->mode))
return 0;
newbase = traverse_path(info, p);
buf0 = fill_tree_descriptor(t+0, n[0].sha1);
buf1 = fill_tree_descriptor(t+1, n[1].sha1);
buf2 = fill_tree_descriptor(t+2, n[2].sha1);
merge_trees(t, newbase);
free(buf0);
free(buf1);
free(buf2);
free(newbase);
return 1;
}
static struct merge_list *link_entry(unsigned stage, const struct traverse_info *info, struct name_entry *n, struct merge_list *entry)
{
const char *path;
struct merge_list *link;
if (!n->mode)
return entry;
if (entry)
path = entry->path;
else
path = traverse_path(info, n);
link = create_entry(stage, n->mode, n->sha1, path);
link->link = entry;
return link;
}
static void unresolved(const struct traverse_info *info, struct name_entry n[3])
{
struct merge_list *entry = NULL;
if (unresolved_directory(info, n))
return;
/*
* Do them in reverse order so that the resulting link
* list has the stages in order - link_entry adds new
* links at the front.
*/
entry = link_entry(3, info, n + 2, entry);
entry = link_entry(2, info, n + 1, entry);
entry = link_entry(1, info, n + 0, entry);
add_merge_entry(entry);
}
/*
* Merge two trees together (t[1] and t[2]), using a common base (t[0])
* as the origin.
*
* This walks the (sorted) trees in lock-step, checking every possible
* name. Note that directories automatically sort differently from other
* files (see "base_name_compare"), so you'll never see file/directory
* conflicts, because they won't ever compare the same.
*
* IOW, if a directory changes to a filename, it will automatically be
* seen as the directory going away, and the filename being created.
*
* Think of this as a three-way diff.
*
* The output will be either:
* - successful merge
* "0 mode sha1 filename"
* NOTE NOTE NOTE! FIXME! We really really need to walk the index
* in parallel with this too!
*
* - conflict:
* "1 mode sha1 filename"
* "2 mode sha1 filename"
* "3 mode sha1 filename"
* where not all of the 1/2/3 lines may exist, of course.
*
* The successful merge rules are the same as for the three-way merge
* in git-read-tree.
*/
static int threeway_callback(int n, unsigned long mask, unsigned long dirmask, struct name_entry *entry, struct traverse_info *info)
{
/* Same in both? */
if (same_entry(entry+1, entry+2)) {
if (entry[0].sha1) {
resolve(info, NULL, entry+1);
return mask;
}
}
if (same_entry(entry+0, entry+1)) {
if (entry[2].sha1 && !S_ISDIR(entry[2].mode)) {
resolve(info, entry+1, entry+2);
return mask;
}
}
if (same_entry(entry+0, entry+2)) {
if (entry[1].sha1 && !S_ISDIR(entry[1].mode)) {
resolve(info, NULL, entry+1);
return mask;
}
}
unresolved(info, entry);
return mask;
}
static void merge_trees(struct tree_desc t[3], const char *base)
{
struct traverse_info info;
setup_traverse_info(&info, base);
info.fn = threeway_callback;
traverse_trees(3, t, &info);
}
static void *get_tree_descriptor(struct tree_desc *desc, const char *rev)
{
unsigned char sha1[20];
void *buf;
if (get_sha1(rev, sha1))
die("unknown rev %s", rev);
buf = fill_tree_descriptor(desc, sha1);
if (!buf)
die("%s is not a tree", rev);
return buf;
}
int cmd_merge_tree(int argc, const char **argv, const char *prefix)
{
struct tree_desc t[3];
void *buf1, *buf2, *buf3;
if (argc != 4)
usage(merge_tree_usage);
buf1 = get_tree_descriptor(t+0, argv[1]);
buf2 = get_tree_descriptor(t+1, argv[2]);
buf3 = get_tree_descriptor(t+2, argv[3]);
merge_trees(t, "");
free(buf1);
free(buf2);
free(buf3);
show_result();
return 0;
}
Jump to Line
Something went wrong with that request. Please try again.