git/merge-recursive.c
Johannes Schindelin fadf488f9b merge-recursive: refuse to merge binary files
[jc: cherry-picked 9f30855 from 'master']

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-06-15 23:28:10 -07:00

1777 lines
44 KiB
C

/*
* Recursive Merge algorithm stolen from git-merge-recursive.py by
* Fredrik Kuivinen.
* The thieves were Alex Riesen and Johannes Schindelin, in June/July 2006
*/
#include "cache.h"
#include "cache-tree.h"
#include "commit.h"
#include "blob.h"
#include "tree-walk.h"
#include "diff.h"
#include "diffcore.h"
#include "run-command.h"
#include "tag.h"
#include "unpack-trees.h"
#include "path-list.h"
#include "xdiff-interface.h"
#include "interpolate.h"
#include "attr.h"
static int subtree_merge;
static struct tree *shift_tree_object(struct tree *one, struct tree *two)
{
unsigned char shifted[20];
/*
* NEEDSWORK: this limits the recursion depth to hardcoded
* value '2' to avoid excessive overhead.
*/
shift_tree(one->object.sha1, two->object.sha1, shifted, 2);
if (!hashcmp(two->object.sha1, shifted))
return two;
return lookup_tree(shifted);
}
/*
* A virtual commit has
* - (const char *)commit->util set to the name, and
* - *(int *)commit->object.sha1 set to the virtual id.
*/
static unsigned commit_list_count(const struct commit_list *l)
{
unsigned c = 0;
for (; l; l = l->next )
c++;
return c;
}
static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
{
struct commit *commit = xcalloc(1, sizeof(struct commit));
static unsigned virtual_id = 1;
commit->tree = tree;
commit->util = (void*)comment;
*(int*)commit->object.sha1 = virtual_id++;
/* avoid warnings */
commit->object.parsed = 1;
return commit;
}
/*
* Since we use get_tree_entry(), which does not put the read object into
* the object pool, we cannot rely on a == b.
*/
static int sha_eq(const unsigned char *a, const unsigned char *b)
{
if (!a && !b)
return 2;
return a && b && hashcmp(a, b) == 0;
}
/*
* Since we want to write the index eventually, we cannot reuse the index
* for these (temporary) data.
*/
struct stage_data
{
struct
{
unsigned mode;
unsigned char sha[20];
} stages[4];
unsigned processed:1;
};
struct output_buffer
{
struct output_buffer *next;
char *str;
};
static struct path_list current_file_set = {NULL, 0, 0, 1};
static struct path_list current_directory_set = {NULL, 0, 0, 1};
static int call_depth = 0;
static int verbosity = 2;
static int buffer_output = 1;
static struct output_buffer *output_list, *output_end;
static int show (int v)
{
return (!call_depth && verbosity >= v) || verbosity >= 5;
}
static void output(int v, const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
if (buffer_output && show(v)) {
struct output_buffer *b = xmalloc(sizeof(*b));
nfvasprintf(&b->str, fmt, args);
b->next = NULL;
if (output_end)
output_end->next = b;
else
output_list = b;
output_end = b;
} else if (show(v)) {
int i;
for (i = call_depth; i--;)
fputs(" ", stdout);
vfprintf(stdout, fmt, args);
fputc('\n', stdout);
}
va_end(args);
}
static void flush_output(void)
{
struct output_buffer *b, *n;
for (b = output_list; b; b = n) {
int i;
for (i = call_depth; i--;)
fputs(" ", stdout);
fputs(b->str, stdout);
fputc('\n', stdout);
n = b->next;
free(b->str);
free(b);
}
output_list = NULL;
output_end = NULL;
}
static void output_commit_title(struct commit *commit)
{
int i;
flush_output();
for (i = call_depth; i--;)
fputs(" ", stdout);
if (commit->util)
printf("virtual %s\n", (char *)commit->util);
else {
printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
if (parse_commit(commit) != 0)
printf("(bad commit)\n");
else {
const char *s;
int len;
for (s = commit->buffer; *s; s++)
if (*s == '\n' && s[1] == '\n') {
s += 2;
break;
}
for (len = 0; s[len] && '\n' != s[len]; len++)
; /* do nothing */
printf("%.*s\n", len, s);
}
}
}
static struct cache_entry *make_cache_entry(unsigned int mode,
const unsigned char *sha1, const char *path, int stage, int refresh)
{
int size, len;
struct cache_entry *ce;
if (!verify_path(path))
return NULL;
len = strlen(path);
size = cache_entry_size(len);
ce = xcalloc(1, size);
hashcpy(ce->sha1, sha1);
memcpy(ce->name, path, len);
ce->ce_flags = create_ce_flags(len, stage);
ce->ce_mode = create_ce_mode(mode);
if (refresh)
return refresh_cache_entry(ce, 0);
return ce;
}
static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
const char *path, int stage, int refresh, int options)
{
struct cache_entry *ce;
ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
if (!ce)
return error("addinfo_cache failed for path '%s'", path);
return add_cache_entry(ce, options);
}
/*
* This is a global variable which is used in a number of places but
* only written to in the 'merge' function.
*
* index_only == 1 => Don't leave any non-stage 0 entries in the cache and
* don't update the working directory.
* 0 => Leave unmerged entries in the cache and update
* the working directory.
*/
static int index_only = 0;
static int git_merge_trees(int index_only,
struct tree *common,
struct tree *head,
struct tree *merge)
{
int rc;
struct object_list *trees = NULL;
struct unpack_trees_options opts;
memset(&opts, 0, sizeof(opts));
if (index_only)
opts.index_only = 1;
else
opts.update = 1;
opts.merge = 1;
opts.head_idx = 2;
opts.fn = threeway_merge;
object_list_append(&common->object, &trees);
object_list_append(&head->object, &trees);
object_list_append(&merge->object, &trees);
rc = unpack_trees(trees, &opts);
cache_tree_free(&active_cache_tree);
return rc;
}
static int unmerged_index(void)
{
int i;
for (i = 0; i < active_nr; i++) {
struct cache_entry *ce = active_cache[i];
if (ce_stage(ce))
return 1;
}
return 0;
}
static struct tree *git_write_tree(void)
{
struct tree *result = NULL;
if (unmerged_index()) {
int i;
output(0, "There are unmerged index entries:");
for (i = 0; i < active_nr; i++) {
struct cache_entry *ce = active_cache[i];
if (ce_stage(ce))
output(0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
}
return NULL;
}
if (!active_cache_tree)
active_cache_tree = cache_tree();
if (!cache_tree_fully_valid(active_cache_tree) &&
cache_tree_update(active_cache_tree,
active_cache, active_nr, 0, 0) < 0)
die("error building trees");
result = lookup_tree(active_cache_tree->sha1);
return result;
}
static int save_files_dirs(const unsigned char *sha1,
const char *base, int baselen, const char *path,
unsigned int mode, int stage)
{
int len = strlen(path);
char *newpath = xmalloc(baselen + len + 1);
memcpy(newpath, base, baselen);
memcpy(newpath + baselen, path, len);
newpath[baselen + len] = '\0';
if (S_ISDIR(mode))
path_list_insert(newpath, &current_directory_set);
else
path_list_insert(newpath, &current_file_set);
free(newpath);
return READ_TREE_RECURSIVE;
}
static int get_files_dirs(struct tree *tree)
{
int n;
if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs) != 0)
return 0;
n = current_file_set.nr + current_directory_set.nr;
return n;
}
/*
* Returns a index_entry instance which doesn't have to correspond to
* a real cache entry in Git's index.
*/
static struct stage_data *insert_stage_data(const char *path,
struct tree *o, struct tree *a, struct tree *b,
struct path_list *entries)
{
struct path_list_item *item;
struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
get_tree_entry(o->object.sha1, path,
e->stages[1].sha, &e->stages[1].mode);
get_tree_entry(a->object.sha1, path,
e->stages[2].sha, &e->stages[2].mode);
get_tree_entry(b->object.sha1, path,
e->stages[3].sha, &e->stages[3].mode);
item = path_list_insert(path, entries);
item->util = e;
return e;
}
/*
* Create a dictionary mapping file names to stage_data objects. The
* dictionary contains one entry for every path with a non-zero stage entry.
*/
static struct path_list *get_unmerged(void)
{
struct path_list *unmerged = xcalloc(1, sizeof(struct path_list));
int i;
unmerged->strdup_paths = 1;
for (i = 0; i < active_nr; i++) {
struct path_list_item *item;
struct stage_data *e;
struct cache_entry *ce = active_cache[i];
if (!ce_stage(ce))
continue;
item = path_list_lookup(ce->name, unmerged);
if (!item) {
item = path_list_insert(ce->name, unmerged);
item->util = xcalloc(1, sizeof(struct stage_data));
}
e = item->util;
e->stages[ce_stage(ce)].mode = ntohl(ce->ce_mode);
hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
}
return unmerged;
}
struct rename
{
struct diff_filepair *pair;
struct stage_data *src_entry;
struct stage_data *dst_entry;
unsigned processed:1;
};
/*
* Get information of all renames which occurred between 'o_tree' and
* 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
* 'b_tree') to be able to associate the correct cache entries with
* the rename information. 'tree' is always equal to either a_tree or b_tree.
*/
static struct path_list *get_renames(struct tree *tree,
struct tree *o_tree,
struct tree *a_tree,
struct tree *b_tree,
struct path_list *entries)
{
int i;
struct path_list *renames;
struct diff_options opts;
renames = xcalloc(1, sizeof(struct path_list));
diff_setup(&opts);
opts.recursive = 1;
opts.detect_rename = DIFF_DETECT_RENAME;
opts.output_format = DIFF_FORMAT_NO_OUTPUT;
if (diff_setup_done(&opts) < 0)
die("diff setup failed");
diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
diffcore_std(&opts);
for (i = 0; i < diff_queued_diff.nr; ++i) {
struct path_list_item *item;
struct rename *re;
struct diff_filepair *pair = diff_queued_diff.queue[i];
if (pair->status != 'R') {
diff_free_filepair(pair);
continue;
}
re = xmalloc(sizeof(*re));
re->processed = 0;
re->pair = pair;
item = path_list_lookup(re->pair->one->path, entries);
if (!item)
re->src_entry = insert_stage_data(re->pair->one->path,
o_tree, a_tree, b_tree, entries);
else
re->src_entry = item->util;
item = path_list_lookup(re->pair->two->path, entries);
if (!item)
re->dst_entry = insert_stage_data(re->pair->two->path,
o_tree, a_tree, b_tree, entries);
else
re->dst_entry = item->util;
item = path_list_insert(pair->one->path, renames);
item->util = re;
}
opts.output_format = DIFF_FORMAT_NO_OUTPUT;
diff_queued_diff.nr = 0;
diff_flush(&opts);
return renames;
}
static int update_stages(const char *path, struct diff_filespec *o,
struct diff_filespec *a, struct diff_filespec *b,
int clear)
{
int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
if (clear)
if (remove_file_from_cache(path))
return -1;
if (o)
if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
return -1;
if (a)
if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
return -1;
if (b)
if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
return -1;
return 0;
}
static int remove_path(const char *name)
{
int ret, len;
char *slash, *dirs;
ret = unlink(name);
if (ret)
return ret;
len = strlen(name);
dirs = xmalloc(len+1);
memcpy(dirs, name, len);
dirs[len] = '\0';
while ((slash = strrchr(name, '/'))) {
*slash = '\0';
len = slash - name;
if (rmdir(name) != 0)
break;
}
free(dirs);
return ret;
}
static int remove_file(int clean, const char *path, int no_wd)
{
int update_cache = index_only || clean;
int update_working_directory = !index_only && !no_wd;
if (update_cache) {
if (remove_file_from_cache(path))
return -1;
}
if (update_working_directory) {
unlink(path);
if (errno != ENOENT || errno != EISDIR)
return -1;
remove_path(path);
}
return 0;
}
static char *unique_path(const char *path, const char *branch)
{
char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
int suffix = 0;
struct stat st;
char *p = newpath + strlen(path);
strcpy(newpath, path);
*(p++) = '~';
strcpy(p, branch);
for (; *p; ++p)
if ('/' == *p)
*p = '_';
while (path_list_has_path(&current_file_set, newpath) ||
path_list_has_path(&current_directory_set, newpath) ||
lstat(newpath, &st) == 0)
sprintf(p, "_%d", suffix++);
path_list_insert(newpath, &current_file_set);
return newpath;
}
static int mkdir_p(const char *path, unsigned long mode)
{
/* path points to cache entries, so xstrdup before messing with it */
char *buf = xstrdup(path);
int result = safe_create_leading_directories(buf);
free(buf);
return result;
}
static void flush_buffer(int fd, const char *buf, unsigned long size)
{
while (size > 0) {
long ret = write_in_full(fd, buf, size);
if (ret < 0) {
/* Ignore epipe */
if (errno == EPIPE)
break;
die("merge-recursive: %s", strerror(errno));
} else if (!ret) {
die("merge-recursive: disk full?");
}
size -= ret;
buf += ret;
}
}
static int make_room_for_path(const char *path)
{
int status;
const char *msg = "failed to create path '%s'%s";
status = mkdir_p(path, 0777);
if (status) {
if (status == -3) {
/* something else exists */
error(msg, path, ": perhaps a D/F conflict?");
return -1;
}
die(msg, path, "");
}
/* Successful unlink is good.. */
if (!unlink(path))
return 0;
/* .. and so is no existing file */
if (errno == ENOENT)
return 0;
/* .. but not some other error (who really cares what?) */
return error(msg, path, ": perhaps a D/F conflict?");
}
static void update_file_flags(const unsigned char *sha,
unsigned mode,
const char *path,
int update_cache,
int update_wd)
{
if (index_only)
update_wd = 0;
if (update_wd) {
enum object_type type;
void *buf;
unsigned long size;
buf = read_sha1_file(sha, &type, &size);
if (!buf)
die("cannot read object %s '%s'", sha1_to_hex(sha), path);
if (type != OBJ_BLOB)
die("blob expected for %s '%s'", sha1_to_hex(sha), path);
if (make_room_for_path(path) < 0) {
update_wd = 0;
goto update_index;
}
if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
int fd;
if (mode & 0100)
mode = 0777;
else
mode = 0666;
fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
if (fd < 0)
die("failed to open %s: %s", path, strerror(errno));
flush_buffer(fd, buf, size);
close(fd);
} else if (S_ISLNK(mode)) {
char *lnk = xmalloc(size + 1);
memcpy(lnk, buf, size);
lnk[size] = '\0';
mkdir_p(path, 0777);
unlink(path);
symlink(lnk, path);
free(lnk);
} else
die("do not know what to do with %06o %s '%s'",
mode, sha1_to_hex(sha), path);
}
update_index:
if (update_cache)
add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
}
static void update_file(int clean,
const unsigned char *sha,
unsigned mode,
const char *path)
{
update_file_flags(sha, mode, path, index_only || clean, !index_only);
}
/* Low level file merging, update and removal */
struct merge_file_info
{
unsigned char sha[20];
unsigned mode;
unsigned clean:1,
merge:1;
};
static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
{
unsigned long size;
enum object_type type;
if (!hashcmp(sha1, null_sha1)) {
mm->ptr = xstrdup("");
mm->size = 0;
return;
}
mm->ptr = read_sha1_file(sha1, &type, &size);
if (!mm->ptr || type != OBJ_BLOB)
die("unable to read blob object %s", sha1_to_hex(sha1));
mm->size = size;
}
/*
* Customizable low-level merge drivers support.
*/
struct ll_merge_driver;
typedef int (*ll_merge_fn)(const struct ll_merge_driver *,
const char *path,
mmfile_t *orig,
mmfile_t *src1, const char *name1,
mmfile_t *src2, const char *name2,
mmbuffer_t *result);
struct ll_merge_driver {
const char *name;
const char *description;
ll_merge_fn fn;
const char *recursive;
struct ll_merge_driver *next;
char *cmdline;
};
/*
* Built-in low-levels
*/
static int ll_xdl_merge(const struct ll_merge_driver *drv_unused,
const char *path_unused,
mmfile_t *orig,
mmfile_t *src1, const char *name1,
mmfile_t *src2, const char *name2,
mmbuffer_t *result)
{
xpparam_t xpp;
if (buffer_is_binary(orig->ptr, orig->size) ||
buffer_is_binary(src1->ptr, src1->size) ||
buffer_is_binary(src2->ptr, src2->size))
return error("Cannot merge binary files: %s vs. %s\n",
name1, name2);
memset(&xpp, 0, sizeof(xpp));
return xdl_merge(orig,
src1, name1,
src2, name2,
&xpp, XDL_MERGE_ZEALOUS,
result);
}
static int ll_union_merge(const struct ll_merge_driver *drv_unused,
const char *path_unused,
mmfile_t *orig,
mmfile_t *src1, const char *name1,
mmfile_t *src2, const char *name2,
mmbuffer_t *result)
{
char *src, *dst;
long size;
const int marker_size = 7;
int status = ll_xdl_merge(drv_unused, path_unused,
orig, src1, NULL, src2, NULL, result);
if (status <= 0)
return status;
size = result->size;
src = dst = result->ptr;
while (size) {
char ch;
if ((marker_size < size) &&
(*src == '<' || *src == '=' || *src == '>')) {
int i;
ch = *src;
for (i = 0; i < marker_size; i++)
if (src[i] != ch)
goto not_a_marker;
if (src[marker_size] != '\n')
goto not_a_marker;
src += marker_size + 1;
size -= marker_size + 1;
continue;
}
not_a_marker:
do {
ch = *src++;
*dst++ = ch;
size--;
} while (ch != '\n' && size);
}
result->size = dst - result->ptr;
return 0;
}
static int ll_binary_merge(const struct ll_merge_driver *drv_unused,
const char *path_unused,
mmfile_t *orig,
mmfile_t *src1, const char *name1,
mmfile_t *src2, const char *name2,
mmbuffer_t *result)
{
/*
* The tentative merge result is "ours" for the final round,
* or common ancestor for an internal merge. Still return
* "conflicted merge" status.
*/
mmfile_t *stolen = index_only ? orig : src1;
result->ptr = stolen->ptr;
result->size = stolen->size;
stolen->ptr = NULL;
return 1;
}
#define LL_BINARY_MERGE 0
#define LL_TEXT_MERGE 1
#define LL_UNION_MERGE 2
static struct ll_merge_driver ll_merge_drv[] = {
{ "binary", "built-in binary merge", ll_binary_merge },
{ "text", "built-in 3-way text merge", ll_xdl_merge },
{ "union", "built-in union merge", ll_union_merge },
};
static void create_temp(mmfile_t *src, char *path)
{
int fd;
strcpy(path, ".merge_file_XXXXXX");
fd = mkstemp(path);
if (fd < 0)
die("unable to create temp-file");
if (write_in_full(fd, src->ptr, src->size) != src->size)
die("unable to write temp-file");
close(fd);
}
/*
* User defined low-level merge driver support.
*/
static int ll_ext_merge(const struct ll_merge_driver *fn,
const char *path,
mmfile_t *orig,
mmfile_t *src1, const char *name1,
mmfile_t *src2, const char *name2,
mmbuffer_t *result)
{
char temp[3][50];
char cmdbuf[2048];
struct interp table[] = {
{ "%O" },
{ "%A" },
{ "%B" },
};
struct child_process child;
const char *args[20];
int status, fd, i;
struct stat st;
if (fn->cmdline == NULL)
die("custom merge driver %s lacks command line.", fn->name);
result->ptr = NULL;
result->size = 0;
create_temp(orig, temp[0]);
create_temp(src1, temp[1]);
create_temp(src2, temp[2]);
interp_set_entry(table, 0, temp[0]);
interp_set_entry(table, 1, temp[1]);
interp_set_entry(table, 2, temp[2]);
output(1, "merging %s using %s", path,
fn->description ? fn->description : fn->name);
interpolate(cmdbuf, sizeof(cmdbuf), fn->cmdline, table, 3);
memset(&child, 0, sizeof(child));
child.argv = args;
args[0] = "sh";
args[1] = "-c";
args[2] = cmdbuf;
args[3] = NULL;
status = run_command(&child);
if (status < -ERR_RUN_COMMAND_FORK)
; /* failure in run-command */
else
status = -status;
fd = open(temp[1], O_RDONLY);
if (fd < 0)
goto bad;
if (fstat(fd, &st))
goto close_bad;
result->size = st.st_size;
result->ptr = xmalloc(result->size + 1);
if (read_in_full(fd, result->ptr, result->size) != result->size) {
free(result->ptr);
result->ptr = NULL;
result->size = 0;
}
close_bad:
close(fd);
bad:
for (i = 0; i < 3; i++)
unlink(temp[i]);
return status;
}
/*
* merge.default and merge.driver configuration items
*/
static struct ll_merge_driver *ll_user_merge, **ll_user_merge_tail;
static const char *default_ll_merge;
static int read_merge_config(const char *var, const char *value)
{
struct ll_merge_driver *fn;
const char *ep, *name;
int namelen;
if (!strcmp(var, "merge.default")) {
if (value)
default_ll_merge = strdup(value);
return 0;
}
/*
* We are not interested in anything but "merge.<name>.variable";
* especially, we do not want to look at variables such as
* "merge.summary", "merge.tool", and "merge.verbosity".
*/
if (prefixcmp(var, "merge.") || (ep = strrchr(var, '.')) == var + 5)
return 0;
/*
* Find existing one as we might be processing merge.<name>.var2
* after seeing merge.<name>.var1.
*/
name = var + 6;
namelen = ep - name;
for (fn = ll_user_merge; fn; fn = fn->next)
if (!strncmp(fn->name, name, namelen) && !fn->name[namelen])
break;
if (!fn) {
char *namebuf;
fn = xcalloc(1, sizeof(struct ll_merge_driver));
namebuf = xmalloc(namelen + 1);
memcpy(namebuf, name, namelen);
namebuf[namelen] = 0;
fn->name = namebuf;
fn->fn = ll_ext_merge;
fn->next = NULL;
*ll_user_merge_tail = fn;
ll_user_merge_tail = &(fn->next);
}
ep++;
if (!strcmp("name", ep)) {
if (!value)
return error("%s: lacks value", var);
fn->description = strdup(value);
return 0;
}
if (!strcmp("driver", ep)) {
if (!value)
return error("%s: lacks value", var);
/*
* merge.<name>.driver specifies the command line:
*
* command-line
*
* The command-line will be interpolated with the following
* tokens and is given to the shell:
*
* %O - temporary file name for the merge base.
* %A - temporary file name for our version.
* %B - temporary file name for the other branches' version.
*
* The external merge driver should write the results in the
* file named by %A, and signal that it has done with zero exit
* status.
*/
fn->cmdline = strdup(value);
return 0;
}
if (!strcmp("recursive", ep)) {
if (!value)
return error("%s: lacks value", var);
fn->recursive = strdup(value);
return 0;
}
return 0;
}
static void initialize_ll_merge(void)
{
if (ll_user_merge_tail)
return;
ll_user_merge_tail = &ll_user_merge;
git_config(read_merge_config);
}
static const struct ll_merge_driver *find_ll_merge_driver(const char *merge_attr)
{
struct ll_merge_driver *fn;
const char *name;
int i;
initialize_ll_merge();
if (ATTR_TRUE(merge_attr))
return &ll_merge_drv[LL_TEXT_MERGE];
else if (ATTR_FALSE(merge_attr))
return &ll_merge_drv[LL_BINARY_MERGE];
else if (ATTR_UNSET(merge_attr)) {
if (!default_ll_merge)
return &ll_merge_drv[LL_TEXT_MERGE];
else
name = default_ll_merge;
}
else
name = merge_attr;
for (fn = ll_user_merge; fn; fn = fn->next)
if (!strcmp(fn->name, name))
return fn;
for (i = 0; i < ARRAY_SIZE(ll_merge_drv); i++)
if (!strcmp(ll_merge_drv[i].name, name))
return &ll_merge_drv[i];
/* default to the 3-way */
return &ll_merge_drv[LL_TEXT_MERGE];
}
static const char *git_path_check_merge(const char *path)
{
static struct git_attr_check attr_merge_check;
if (!attr_merge_check.attr)
attr_merge_check.attr = git_attr("merge", 5);
if (git_checkattr(path, 1, &attr_merge_check))
return NULL;
return attr_merge_check.value;
}
static int ll_merge(mmbuffer_t *result_buf,
struct diff_filespec *o,
struct diff_filespec *a,
struct diff_filespec *b,
const char *branch1,
const char *branch2)
{
mmfile_t orig, src1, src2;
char *name1, *name2;
int merge_status;
const char *ll_driver_name;
const struct ll_merge_driver *driver;
name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
fill_mm(o->sha1, &orig);
fill_mm(a->sha1, &src1);
fill_mm(b->sha1, &src2);
ll_driver_name = git_path_check_merge(a->path);
driver = find_ll_merge_driver(ll_driver_name);
if (index_only && driver->recursive)
driver = find_ll_merge_driver(driver->recursive);
merge_status = driver->fn(driver, a->path,
&orig, &src1, name1, &src2, name2,
result_buf);
free(name1);
free(name2);
free(orig.ptr);
free(src1.ptr);
free(src2.ptr);
return merge_status;
}
static struct merge_file_info merge_file(struct diff_filespec *o,
struct diff_filespec *a, struct diff_filespec *b,
const char *branch1, const char *branch2)
{
struct merge_file_info result;
result.merge = 0;
result.clean = 1;
if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
result.clean = 0;
if (S_ISREG(a->mode)) {
result.mode = a->mode;
hashcpy(result.sha, a->sha1);
} else {
result.mode = b->mode;
hashcpy(result.sha, b->sha1);
}
} else {
if (!sha_eq(a->sha1, o->sha1) && !sha_eq(b->sha1, o->sha1))
result.merge = 1;
result.mode = a->mode == o->mode ? b->mode: a->mode;
if (sha_eq(a->sha1, o->sha1))
hashcpy(result.sha, b->sha1);
else if (sha_eq(b->sha1, o->sha1))
hashcpy(result.sha, a->sha1);
else if (S_ISREG(a->mode)) {
mmbuffer_t result_buf;
int merge_status;
merge_status = ll_merge(&result_buf, o, a, b,
branch1, branch2);
if ((merge_status < 0) || !result_buf.ptr)
die("Failed to execute internal merge");
if (write_sha1_file(result_buf.ptr, result_buf.size,
blob_type, result.sha))
die("Unable to add %s to database",
a->path);
free(result_buf.ptr);
result.clean = (merge_status == 0);
} else {
if (!(S_ISLNK(a->mode) || S_ISLNK(b->mode)))
die("cannot merge modes?");
hashcpy(result.sha, a->sha1);
if (!sha_eq(a->sha1, b->sha1))
result.clean = 0;
}
}
return result;
}
static void conflict_rename_rename(struct rename *ren1,
const char *branch1,
struct rename *ren2,
const char *branch2)
{
char *del[2];
int delp = 0;
const char *ren1_dst = ren1->pair->two->path;
const char *ren2_dst = ren2->pair->two->path;
const char *dst_name1 = ren1_dst;
const char *dst_name2 = ren2_dst;
if (path_list_has_path(&current_directory_set, ren1_dst)) {
dst_name1 = del[delp++] = unique_path(ren1_dst, branch1);
output(1, "%s is a directory in %s added as %s instead",
ren1_dst, branch2, dst_name1);
remove_file(0, ren1_dst, 0);
}
if (path_list_has_path(&current_directory_set, ren2_dst)) {
dst_name2 = del[delp++] = unique_path(ren2_dst, branch2);
output(1, "%s is a directory in %s added as %s instead",
ren2_dst, branch1, dst_name2);
remove_file(0, ren2_dst, 0);
}
if (index_only) {
remove_file_from_cache(dst_name1);
remove_file_from_cache(dst_name2);
/*
* Uncomment to leave the conflicting names in the resulting tree
*
* update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
* update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
*/
} else {
update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
}
while (delp--)
free(del[delp]);
}
static void conflict_rename_dir(struct rename *ren1,
const char *branch1)
{
char *new_path = unique_path(ren1->pair->two->path, branch1);
output(1, "Renamed %s to %s instead", ren1->pair->one->path, new_path);
remove_file(0, ren1->pair->two->path, 0);
update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
free(new_path);
}
static void conflict_rename_rename_2(struct rename *ren1,
const char *branch1,
struct rename *ren2,
const char *branch2)
{
char *new_path1 = unique_path(ren1->pair->two->path, branch1);
char *new_path2 = unique_path(ren2->pair->two->path, branch2);
output(1, "Renamed %s to %s and %s to %s instead",
ren1->pair->one->path, new_path1,
ren2->pair->one->path, new_path2);
remove_file(0, ren1->pair->two->path, 0);
update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
free(new_path2);
free(new_path1);
}
static int process_renames(struct path_list *a_renames,
struct path_list *b_renames,
const char *a_branch,
const char *b_branch)
{
int clean_merge = 1, i, j;
struct path_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
const struct rename *sre;
for (i = 0; i < a_renames->nr; i++) {
sre = a_renames->items[i].util;
path_list_insert(sre->pair->two->path, &a_by_dst)->util
= sre->dst_entry;
}
for (i = 0; i < b_renames->nr; i++) {
sre = b_renames->items[i].util;
path_list_insert(sre->pair->two->path, &b_by_dst)->util
= sre->dst_entry;
}
for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
int compare;
char *src;
struct path_list *renames1, *renames2, *renames2Dst;
struct rename *ren1 = NULL, *ren2 = NULL;
const char *branch1, *branch2;
const char *ren1_src, *ren1_dst;
if (i >= a_renames->nr) {
compare = 1;
ren2 = b_renames->items[j++].util;
} else if (j >= b_renames->nr) {
compare = -1;
ren1 = a_renames->items[i++].util;
} else {
compare = strcmp(a_renames->items[i].path,
b_renames->items[j].path);
if (compare <= 0)
ren1 = a_renames->items[i++].util;
if (compare >= 0)
ren2 = b_renames->items[j++].util;
}
/* TODO: refactor, so that 1/2 are not needed */
if (ren1) {
renames1 = a_renames;
renames2 = b_renames;
renames2Dst = &b_by_dst;
branch1 = a_branch;
branch2 = b_branch;
} else {
struct rename *tmp;
renames1 = b_renames;
renames2 = a_renames;
renames2Dst = &a_by_dst;
branch1 = b_branch;
branch2 = a_branch;
tmp = ren2;
ren2 = ren1;
ren1 = tmp;
}
src = ren1->pair->one->path;
ren1->dst_entry->processed = 1;
ren1->src_entry->processed = 1;
if (ren1->processed)
continue;
ren1->processed = 1;
ren1_src = ren1->pair->one->path;
ren1_dst = ren1->pair->two->path;
if (ren2) {
const char *ren2_src = ren2->pair->one->path;
const char *ren2_dst = ren2->pair->two->path;
/* Renamed in 1 and renamed in 2 */
if (strcmp(ren1_src, ren2_src) != 0)
die("ren1.src != ren2.src");
ren2->dst_entry->processed = 1;
ren2->processed = 1;
if (strcmp(ren1_dst, ren2_dst) != 0) {
clean_merge = 0;
output(1, "CONFLICT (rename/rename): "
"Rename \"%s\"->\"%s\" in branch \"%s\" "
"rename \"%s\"->\"%s\" in \"%s\"%s",
src, ren1_dst, branch1,
src, ren2_dst, branch2,
index_only ? " (left unresolved)": "");
if (index_only) {
remove_file_from_cache(src);
update_file(0, ren1->pair->one->sha1,
ren1->pair->one->mode, src);
}
conflict_rename_rename(ren1, branch1, ren2, branch2);
} else {
struct merge_file_info mfi;
remove_file(1, ren1_src, 1);
mfi = merge_file(ren1->pair->one,
ren1->pair->two,
ren2->pair->two,
branch1,
branch2);
if (mfi.merge || !mfi.clean)
output(1, "Renamed %s->%s", src, ren1_dst);
if (mfi.merge)
output(2, "Auto-merged %s", ren1_dst);
if (!mfi.clean) {
output(1, "CONFLICT (content): merge conflict in %s",
ren1_dst);
clean_merge = 0;
if (!index_only)
update_stages(ren1_dst,
ren1->pair->one,
ren1->pair->two,
ren2->pair->two,
1 /* clear */);
}
update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
}
} else {
/* Renamed in 1, maybe changed in 2 */
struct path_list_item *item;
/* we only use sha1 and mode of these */
struct diff_filespec src_other, dst_other;
int try_merge, stage = a_renames == renames1 ? 3: 2;
remove_file(1, ren1_src, index_only || stage == 3);
hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
src_other.mode = ren1->src_entry->stages[stage].mode;
hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
dst_other.mode = ren1->dst_entry->stages[stage].mode;
try_merge = 0;
if (path_list_has_path(&current_directory_set, ren1_dst)) {
clean_merge = 0;
output(1, "CONFLICT (rename/directory): Renamed %s->%s in %s "
" directory %s added in %s",
ren1_src, ren1_dst, branch1,
ren1_dst, branch2);
conflict_rename_dir(ren1, branch1);
} else if (sha_eq(src_other.sha1, null_sha1)) {
clean_merge = 0;
output(1, "CONFLICT (rename/delete): Renamed %s->%s in %s "
"and deleted in %s",
ren1_src, ren1_dst, branch1,
branch2);
update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
} else if (!sha_eq(dst_other.sha1, null_sha1)) {
const char *new_path;
clean_merge = 0;
try_merge = 1;
output(1, "CONFLICT (rename/add): Renamed %s->%s in %s. "
"%s added in %s",
ren1_src, ren1_dst, branch1,
ren1_dst, branch2);
new_path = unique_path(ren1_dst, branch2);
output(1, "Added as %s instead", new_path);
update_file(0, dst_other.sha1, dst_other.mode, new_path);
} else if ((item = path_list_lookup(ren1_dst, renames2Dst))) {
ren2 = item->util;
clean_merge = 0;
ren2->processed = 1;
output(1, "CONFLICT (rename/rename): Renamed %s->%s in %s. "
"Renamed %s->%s in %s",
ren1_src, ren1_dst, branch1,
ren2->pair->one->path, ren2->pair->two->path, branch2);
conflict_rename_rename_2(ren1, branch1, ren2, branch2);
} else
try_merge = 1;
if (try_merge) {
struct diff_filespec *o, *a, *b;
struct merge_file_info mfi;
src_other.path = (char *)ren1_src;
o = ren1->pair->one;
if (a_renames == renames1) {
a = ren1->pair->two;
b = &src_other;
} else {
b = ren1->pair->two;
a = &src_other;
}
mfi = merge_file(o, a, b,
a_branch, b_branch);
if (mfi.clean &&
sha_eq(mfi.sha, ren1->pair->two->sha1) &&
mfi.mode == ren1->pair->two->mode)
/*
* This messaged is part of
* t6022 test. If you change
* it update the test too.
*/
output(3, "Skipped %s (merged same as existing)", ren1_dst);
else {
if (mfi.merge || !mfi.clean)
output(1, "Renamed %s => %s", ren1_src, ren1_dst);
if (mfi.merge)
output(2, "Auto-merged %s", ren1_dst);
if (!mfi.clean) {
output(1, "CONFLICT (rename/modify): Merge conflict in %s",
ren1_dst);
clean_merge = 0;
if (!index_only)
update_stages(ren1_dst,
o, a, b, 1);
}
update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
}
}
}
}
path_list_clear(&a_by_dst, 0);
path_list_clear(&b_by_dst, 0);
return clean_merge;
}
static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
{
return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
}
/* Per entry merge function */
static int process_entry(const char *path, struct stage_data *entry,
const char *branch1,
const char *branch2)
{
/*
printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
print_index_entry("\tpath: ", entry);
*/
int clean_merge = 1;
unsigned o_mode = entry->stages[1].mode;
unsigned a_mode = entry->stages[2].mode;
unsigned b_mode = entry->stages[3].mode;
unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
if (o_sha && (!a_sha || !b_sha)) {
/* Case A: Deleted in one */
if ((!a_sha && !b_sha) ||
(sha_eq(a_sha, o_sha) && !b_sha) ||
(!a_sha && sha_eq(b_sha, o_sha))) {
/* Deleted in both or deleted in one and
* unchanged in the other */
if (a_sha)
output(2, "Removed %s", path);
/* do not touch working file if it did not exist */
remove_file(1, path, !a_sha);
} else {
/* Deleted in one and changed in the other */
clean_merge = 0;
if (!a_sha) {
output(1, "CONFLICT (delete/modify): %s deleted in %s "
"and modified in %s. Version %s of %s left in tree.",
path, branch1,
branch2, branch2, path);
update_file(0, b_sha, b_mode, path);
} else {
output(1, "CONFLICT (delete/modify): %s deleted in %s "
"and modified in %s. Version %s of %s left in tree.",
path, branch2,
branch1, branch1, path);
update_file(0, a_sha, a_mode, path);
}
}
} else if ((!o_sha && a_sha && !b_sha) ||
(!o_sha && !a_sha && b_sha)) {
/* Case B: Added in one. */
const char *add_branch;
const char *other_branch;
unsigned mode;
const unsigned char *sha;
const char *conf;
if (a_sha) {
add_branch = branch1;
other_branch = branch2;
mode = a_mode;
sha = a_sha;
conf = "file/directory";
} else {
add_branch = branch2;
other_branch = branch1;
mode = b_mode;
sha = b_sha;
conf = "directory/file";
}
if (path_list_has_path(&current_directory_set, path)) {
const char *new_path = unique_path(path, add_branch);
clean_merge = 0;
output(1, "CONFLICT (%s): There is a directory with name %s in %s. "
"Added %s as %s",
conf, path, other_branch, path, new_path);
remove_file(0, path, 0);
update_file(0, sha, mode, new_path);
} else {
output(2, "Added %s", path);
update_file(1, sha, mode, path);
}
} else if (a_sha && b_sha) {
/* Case C: Added in both (check for same permissions) and */
/* case D: Modified in both, but differently. */
const char *reason = "content";
struct merge_file_info mfi;
struct diff_filespec o, a, b;
if (!o_sha) {
reason = "add/add";
o_sha = (unsigned char *)null_sha1;
}
output(2, "Auto-merged %s", path);
o.path = a.path = b.path = (char *)path;
hashcpy(o.sha1, o_sha);
o.mode = o_mode;
hashcpy(a.sha1, a_sha);
a.mode = a_mode;
hashcpy(b.sha1, b_sha);
b.mode = b_mode;
mfi = merge_file(&o, &a, &b,
branch1, branch2);
if (mfi.clean)
update_file(1, mfi.sha, mfi.mode, path);
else {
clean_merge = 0;
output(1, "CONFLICT (%s): Merge conflict in %s",
reason, path);
if (index_only)
update_file(0, mfi.sha, mfi.mode, path);
else
update_file_flags(mfi.sha, mfi.mode, path,
0 /* update_cache */, 1 /* update_working_directory */);
}
} else if (!o_sha && !a_sha && !b_sha) {
/*
* this entry was deleted altogether. a_mode == 0 means
* we had that path and want to actively remove it.
*/
remove_file(1, path, !a_mode);
} else
die("Fatal merge failure, shouldn't happen.");
return clean_merge;
}
static int merge_trees(struct tree *head,
struct tree *merge,
struct tree *common,
const char *branch1,
const char *branch2,
struct tree **result)
{
int code, clean;
if (subtree_merge) {
merge = shift_tree_object(head, merge);
common = shift_tree_object(head, common);
}
if (sha_eq(common->object.sha1, merge->object.sha1)) {
output(0, "Already uptodate!");
*result = head;
return 1;
}
code = git_merge_trees(index_only, common, head, merge);
if (code != 0)
die("merging of trees %s and %s failed",
sha1_to_hex(head->object.sha1),
sha1_to_hex(merge->object.sha1));
if (unmerged_index()) {
struct path_list *entries, *re_head, *re_merge;
int i;
path_list_clear(&current_file_set, 1);
path_list_clear(&current_directory_set, 1);
get_files_dirs(head);
get_files_dirs(merge);
entries = get_unmerged();
re_head = get_renames(head, common, head, merge, entries);
re_merge = get_renames(merge, common, head, merge, entries);
clean = process_renames(re_head, re_merge,
branch1, branch2);
for (i = 0; i < entries->nr; i++) {
const char *path = entries->items[i].path;
struct stage_data *e = entries->items[i].util;
if (!e->processed
&& !process_entry(path, e, branch1, branch2))
clean = 0;
}
path_list_clear(re_merge, 0);
path_list_clear(re_head, 0);
path_list_clear(entries, 1);
}
else
clean = 1;
if (index_only)
*result = git_write_tree();
return clean;
}
static struct commit_list *reverse_commit_list(struct commit_list *list)
{
struct commit_list *next = NULL, *current, *backup;
for (current = list; current; current = backup) {
backup = current->next;
current->next = next;
next = current;
}
return next;
}
/*
* Merge the commits h1 and h2, return the resulting virtual
* commit object and a flag indicating the cleanness of the merge.
*/
static int merge(struct commit *h1,
struct commit *h2,
const char *branch1,
const char *branch2,
struct commit_list *ca,
struct commit **result)
{
struct commit_list *iter;
struct commit *merged_common_ancestors;
struct tree *mrtree;
int clean;
if (show(4)) {
output(4, "Merging:");
output_commit_title(h1);
output_commit_title(h2);
}
if (!ca) {
ca = get_merge_bases(h1, h2, 1);
ca = reverse_commit_list(ca);
}
if (show(5)) {
output(5, "found %u common ancestor(s):", commit_list_count(ca));
for (iter = ca; iter; iter = iter->next)
output_commit_title(iter->item);
}
merged_common_ancestors = pop_commit(&ca);
if (merged_common_ancestors == NULL) {
/* if there is no common ancestor, make an empty tree */
struct tree *tree = xcalloc(1, sizeof(struct tree));
tree->object.parsed = 1;
tree->object.type = OBJ_TREE;
pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
merged_common_ancestors = make_virtual_commit(tree, "ancestor");
}
for (iter = ca; iter; iter = iter->next) {
call_depth++;
/*
* When the merge fails, the result contains files
* with conflict markers. The cleanness flag is
* ignored, it was never actually used, as result of
* merge_trees has always overwritten it: the committed
* "conflicts" were already resolved.
*/
discard_cache();
merge(merged_common_ancestors, iter->item,
"Temporary merge branch 1",
"Temporary merge branch 2",
NULL,
&merged_common_ancestors);
call_depth--;
if (!merged_common_ancestors)
die("merge returned no commit");
}
discard_cache();
if (!call_depth) {
read_cache();
index_only = 0;
} else
index_only = 1;
clean = merge_trees(h1->tree, h2->tree, merged_common_ancestors->tree,
branch1, branch2, &mrtree);
if (index_only) {
*result = make_virtual_commit(mrtree, "merged tree");
commit_list_insert(h1, &(*result)->parents);
commit_list_insert(h2, &(*result)->parents->next);
}
flush_output();
return clean;
}
static const char *better_branch_name(const char *branch)
{
static char githead_env[8 + 40 + 1];
char *name;
if (strlen(branch) != 40)
return branch;
sprintf(githead_env, "GITHEAD_%s", branch);
name = getenv(githead_env);
return name ? name : branch;
}
static struct commit *get_ref(const char *ref)
{
unsigned char sha1[20];
struct object *object;
if (get_sha1(ref, sha1))
die("Could not resolve ref '%s'", ref);
object = deref_tag(parse_object(sha1), ref, strlen(ref));
if (object->type == OBJ_TREE)
return make_virtual_commit((struct tree*)object,
better_branch_name(ref));
if (object->type != OBJ_COMMIT)
return NULL;
if (parse_commit((struct commit *)object))
die("Could not parse commit '%s'", sha1_to_hex(object->sha1));
return (struct commit *)object;
}
static int merge_config(const char *var, const char *value)
{
if (!strcasecmp(var, "merge.verbosity")) {
verbosity = git_config_int(var, value);
return 0;
}
return git_default_config(var, value);
}
int main(int argc, char *argv[])
{
static const char *bases[20];
static unsigned bases_count = 0;
int i, clean;
const char *branch1, *branch2;
struct commit *result, *h1, *h2;
struct commit_list *ca = NULL;
struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
int index_fd;
if (argv[0]) {
int namelen = strlen(argv[0]);
if (8 < namelen &&
!strcmp(argv[0] + namelen - 8, "-subtree"))
subtree_merge = 1;
}
git_config(merge_config);
if (getenv("GIT_MERGE_VERBOSITY"))
verbosity = strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
if (argc < 4)
die("Usage: %s <base>... -- <head> <remote> ...\n", argv[0]);
for (i = 1; i < argc; ++i) {
if (!strcmp(argv[i], "--"))
break;
if (bases_count < sizeof(bases)/sizeof(*bases))
bases[bases_count++] = argv[i];
}
if (argc - i != 3) /* "--" "<head>" "<remote>" */
die("Not handling anything other than two heads merge.");
if (verbosity >= 5)
buffer_output = 0;
branch1 = argv[++i];
branch2 = argv[++i];
h1 = get_ref(branch1);
h2 = get_ref(branch2);
branch1 = better_branch_name(branch1);
branch2 = better_branch_name(branch2);
if (show(3))
printf("Merging %s with %s\n", branch1, branch2);
index_fd = hold_locked_index(lock, 1);
for (i = 0; i < bases_count; i++) {
struct commit *ancestor = get_ref(bases[i]);
ca = commit_list_insert(ancestor, &ca);
}
clean = merge(h1, h2, branch1, branch2, ca, &result);
if (active_cache_changed &&
(write_cache(index_fd, active_cache, active_nr) ||
close(index_fd) || commit_locked_index(lock)))
die ("unable to write %s", get_index_file());
return clean ? 0: 1;
}