/*
* Copyright (C) the libgit2 contributors. All rights reserved.
*
* This file is part of libgit2, distributed under the GNU GPL v2 with
* a Linking Exception. For full terms see the included COPYING file.
*/
#include "merge_driver.h"
#include "vector.h"
#include "runtime.h"
#include "merge.h"
#include "git2/merge.h"
#include "git2/sys/merge.h"
static const char *merge_driver_name__text = "text";
static const char *merge_driver_name__union = "union";
static const char *merge_driver_name__binary = "binary";
struct merge_driver_registry {
git_rwlock lock;
git_vector drivers;
};
typedef struct {
git_merge_driver *driver;
int initialized;
char name[GIT_FLEX_ARRAY];
} git_merge_driver_entry;
static struct merge_driver_registry merge_driver_registry;
static void git_merge_driver_global_shutdown(void);
git_repository *git_merge_driver_source_repo(
const git_merge_driver_source *src)
{
GIT_ASSERT_ARG_WITH_RETVAL(src, NULL);
return src->repo;
}
const git_index_entry *git_merge_driver_source_ancestor(
const git_merge_driver_source *src)
{
GIT_ASSERT_ARG_WITH_RETVAL(src, NULL);
return src->ancestor;
}
const git_index_entry *git_merge_driver_source_ours(
const git_merge_driver_source *src)
{
GIT_ASSERT_ARG_WITH_RETVAL(src, NULL);
return src->ours;
}
const git_index_entry *git_merge_driver_source_theirs(
const git_merge_driver_source *src)
{
GIT_ASSERT_ARG_WITH_RETVAL(src, NULL);
return src->theirs;
}
const git_merge_file_options *git_merge_driver_source_file_options(
const git_merge_driver_source *src)
{
GIT_ASSERT_ARG_WITH_RETVAL(src, NULL);
return src->file_opts;
}
int git_merge_driver__builtin_apply(
git_merge_driver *self,
const char **path_out,
uint32_t *mode_out,
git_buf *merged_out,
const char *filter_name,
const git_merge_driver_source *src)
{
git_merge_driver__builtin *driver = (git_merge_driver__builtin *)self;
git_merge_file_options file_opts = GIT_MERGE_FILE_OPTIONS_INIT;
git_merge_file_result result = {0};
int error;
GIT_UNUSED(filter_name);
if (src->file_opts)
memcpy(&file_opts, src->file_opts, sizeof(git_merge_file_options));
if (driver->favor)
file_opts.favor = driver->favor;
if ((error = git_merge_file_from_index(&result, src->repo,
src->ancestor, src->ours, src->theirs, &file_opts)) < 0)
goto done;
if (!result.automergeable &&
!(file_opts.flags & GIT_MERGE_FILE_FAVOR__CONFLICTED)) {
error = GIT_EMERGECONFLICT;
goto done;
}
*path_out = git_merge_file__best_path(
src->ancestor ? src->ancestor->path : NULL,
src->ours ? src->ours->path : NULL,
src->theirs ? src->theirs->path : NULL);
*mode_out = git_merge_file__best_mode(
src->ancestor ? src->ancestor->mode : 0,
src->ours ? src->ours->mode : 0,
src->theirs ? src->theirs->mode : 0);
merged_out->ptr = (char *)result.ptr;
merged_out->size = result.len;
merged_out->asize = result.len;
result.ptr = NULL;
done:
git_merge_file_result_free(&result);
return error;
}
static int merge_driver_binary_apply(
git_merge_driver *self,
const char **path_out,
uint32_t *mode_out,
git_buf *merged_out,
const char *filter_name,
const git_merge_driver_source *src)
{
GIT_UNUSED(self);
GIT_UNUSED(path_out);
GIT_UNUSED(mode_out);
GIT_UNUSED(merged_out);
GIT_UNUSED(filter_name);
GIT_UNUSED(src);
return GIT_EMERGECONFLICT;
}
static int merge_driver_entry_cmp(const void *a, const void *b)
{
const git_merge_driver_entry *entry_a = a;
const git_merge_driver_entry *entry_b = b;
return strcmp(entry_a->name, entry_b->name);
}
static int merge_driver_entry_search(const void *a, const void *b)
{
const char *name_a = a;
const git_merge_driver_entry *entry_b = b;
return strcmp(name_a, entry_b->name);
}
git_merge_driver__builtin git_merge_driver__text = {
{
GIT_MERGE_DRIVER_VERSION,
NULL,
NULL,
git_merge_driver__builtin_apply,
},
GIT_MERGE_FILE_FAVOR_NORMAL
};
git_merge_driver__builtin git_merge_driver__union = {
{
GIT_MERGE_DRIVER_VERSION,
NULL,
NULL,
git_merge_driver__builtin_apply,
},
GIT_MERGE_FILE_FAVOR_UNION
};
git_merge_driver git_merge_driver__binary = {
GIT_MERGE_DRIVER_VERSION,
NULL,
NULL,
merge_driver_binary_apply
};
/* Note: callers must lock the registry before calling this function */
static int merge_driver_registry_insert(
const char *name, git_merge_driver *driver)
{
git_merge_driver_entry *entry;
entry = git__calloc(1, sizeof(git_merge_driver_entry) + strlen(name) + 1);
GIT_ERROR_CHECK_ALLOC(entry);
strcpy(entry->name, name);
entry->driver = driver;
return git_vector_insert_sorted(
&merge_driver_registry.drivers, entry, NULL);
}
int git_merge_driver_global_init(void)
{
int error;
if (git_rwlock_init(&merge_driver_registry.lock) < 0)
return -1;
if ((error = git_vector_init(&merge_driver_registry.drivers, 3,
merge_driver_entry_cmp)) < 0)
goto done;
if ((error = merge_driver_registry_insert(
merge_driver_name__text, &git_merge_driver__text.base)) < 0 ||
(error = merge_driver_registry_insert(
merge_driver_name__union, &git_merge_driver__union.base)) < 0 ||
(error = merge_driver_registry_insert(
merge_driver_name__binary, &git_merge_driver__binary)) < 0)
goto done;
error = git_runtime_shutdown_register(git_merge_driver_global_shutdown);
done:
if (error < 0)
git_vector_free_deep(&merge_driver_registry.drivers);
return error;
}
static void git_merge_driver_global_shutdown(void)
{
git_merge_driver_entry *entry;
size_t i;
if (git_rwlock_wrlock(&merge_driver_registry.lock) < 0)
return;
git_vector_foreach(&merge_driver_registry.drivers, i, entry) {
if (entry->driver->shutdown)
entry->driver->shutdown(entry->driver);
git__free(entry);
}
git_vector_free(&merge_driver_registry.drivers);
git_rwlock_wrunlock(&merge_driver_registry.lock);
git_rwlock_free(&merge_driver_registry.lock);
}
/* Note: callers must lock the registry before calling this function */
static int merge_driver_registry_find(size_t *pos, const char *name)
{
return git_vector_search2(pos, &merge_driver_registry.drivers,
merge_driver_entry_search, name);
}
/* Note: callers must lock the registry before calling this function */
static git_merge_driver_entry *merge_driver_registry_lookup(
size_t *pos, const char *name)
{
git_merge_driver_entry *entry = NULL;
if (!merge_driver_registry_find(pos, name))
entry = git_vector_get(&merge_driver_registry.drivers, *pos);
return entry;
}
int git_merge_driver_register(const char *name, git_merge_driver *driver)
{
int error;
GIT_ASSERT_ARG(name);
GIT_ASSERT_ARG(driver);
if (git_rwlock_wrlock(&merge_driver_registry.lock) < 0) {
git_error_set(GIT_ERROR_OS, "failed to lock merge driver registry");
return -1;
}
if (!merge_driver_registry_find(NULL, name)) {
git_error_set(GIT_ERROR_MERGE, "attempt to reregister existing driver '%s'",
name);
error = GIT_EEXISTS;
goto done;
}
error = merge_driver_registry_insert(name, driver);
done:
git_rwlock_wrunlock(&merge_driver_registry.lock);
return error;
}
int git_merge_driver_unregister(const char *name)
{
git_merge_driver_entry *entry;
size_t pos;
int error = 0;
if (git_rwlock_wrlock(&merge_driver_registry.lock) < 0) {
git_error_set(GIT_ERROR_OS, "failed to lock merge driver registry");
return -1;
}
if ((entry = merge_driver_registry_lookup(&pos, name)) == NULL) {
git_error_set(GIT_ERROR_MERGE, "cannot find merge driver '%s' to unregister",
name);
error = GIT_ENOTFOUND;
goto done;
}
git_vector_remove(&merge_driver_registry.drivers, pos);
if (entry->initialized && entry->driver->shutdown) {
entry->driver->shutdown(entry->driver);
entry->initialized = false;
}
git__free(entry);
done:
git_rwlock_wrunlock(&merge_driver_registry.lock);
return error;
}
git_merge_driver *git_merge_driver_lookup(const char *name)
{
git_merge_driver_entry *entry;
size_t pos;
int error;
/* If we've decided the merge driver to use internally - and not
* based on user configuration (in merge_driver_name_for_path)
* then we can use a hardcoded name to compare instead of bothering
* to take a lock and look it up in the vector.
*/
if (name == merge_driver_name__text)
return &git_merge_driver__text.base;
else if (name == merge_driver_name__binary)
return &git_merge_driver__binary;
if (git_rwlock_rdlock(&merge_driver_registry.lock) < 0) {
git_error_set(GIT_ERROR_OS, "failed to lock merge driver registry");
return NULL;
}
entry = merge_driver_registry_lookup(&pos, name);
git_rwlock_rdunlock(&merge_driver_registry.lock);
if (entry == NULL) {
git_error_set(GIT_ERROR_MERGE, "cannot use an unregistered filter");
return NULL;
}
if (!entry->initialized) {
if (entry->driver->initialize &&
(error = entry->driver->initialize(entry->driver)) < 0)
return NULL;
entry->initialized = 1;
}
return entry->driver;
}
static int merge_driver_name_for_path(
const char **out,
git_repository *repo,
const char *path,
const char *default_driver)
{
const char *value;
int error;
*out = NULL;
if ((error = git_attr_get(&value, repo, 0, path, "merge")) < 0)
return error;
/* set: use the built-in 3-way merge driver ("text") */
if (GIT_ATTR_IS_TRUE(value))
*out = merge_driver_name__text;
/* unset: do not merge ("binary") */
else if (GIT_ATTR_IS_FALSE(value))
*out = merge_driver_name__binary;
else if (GIT_ATTR_IS_UNSPECIFIED(value) && default_driver)
*out = default_driver;
else if (GIT_ATTR_IS_UNSPECIFIED(value))
*out = merge_driver_name__text;
else
*out = value;
return 0;
}
GIT_INLINE(git_merge_driver *) merge_driver_lookup_with_wildcard(
const char *name)
{
git_merge_driver *driver = git_merge_driver_lookup(name);
if (driver == NULL)
driver = git_merge_driver_lookup("*");
return driver;
}
int git_merge_driver_for_source(
const char **name_out,
git_merge_driver **driver_out,
const git_merge_driver_source *src)
{
const char *path, *driver_name;
int error = 0;
path = git_merge_file__best_path(
src->ancestor ? src->ancestor->path : NULL,
src->ours ? src->ours->path : NULL,
src->theirs ? src->theirs->path : NULL);
if ((error = merge_driver_name_for_path(
&driver_name, src->repo, path, src->default_driver)) < 0)
return error;
*name_out = driver_name;
*driver_out = merge_driver_lookup_with_wildcard(driver_name);
return error;
}
