dir.[ch]: replace dir_init() with DIR_INIT

Remove the dir_init() function and replace it with a DIR_INIT
macro. In many cases in the codebase we need to initialize things with
a function for good reasons, e.g. needing to call another function on
initialization. The "dir_init()" function was not one such case, and
could trivially be replaced with a more idiomatic macro initialization
pattern.

The only place where we made use of its use of memset() was in
dir_clear() itself, which resets the contents of an an existing struct
pointer. Let's use the new "memcpy() a 'blank' struct on the stack"
idiom to do that reset.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/add.c

@@ -470,7 +470,7 @@ int cmd_add(int argc, const char **argv, const char *prefix)
 {
 	int exit_status = 0;
 	struct pathspec pathspec;
-	struct dir_struct dir;
+	struct dir_struct dir = DIR_INIT;
 	int flags;
 	int add_new_files;
 	int require_pathspec;
@@ -577,7 +577,6 @@ int cmd_add(int argc, const char **argv, const char *prefix)
 	die_in_unpopulated_submodule(&the_index, prefix);
 	die_path_inside_submodule(&the_index, &pathspec);
 
-	dir_init(&dir);
 	if (add_new_files) {
 		int baselen;
 

builtin/check-ignore.c

@@ -153,7 +153,7 @@ static int check_ignore_stdin_paths(struct dir_struct *dir, const char *prefix)
 int cmd_check_ignore(int argc, const char **argv, const char *prefix)
 {
 	int num_ignored;
-	struct dir_struct dir;
+	struct dir_struct dir = DIR_INIT;
 
 	git_config(git_default_config, NULL);
 
@@ -182,7 +182,6 @@ int cmd_check_ignore(int argc, const char **argv, const char *prefix)
 	if (!no_index && read_cache() < 0)
 		die(_("index file corrupt"));
 
-	dir_init(&dir);
 	setup_standard_excludes(&dir);
 
 	if (stdin_paths) {

builtin/clean.c

@@ -641,7 +641,7 @@ static int clean_cmd(void)
 
 static int filter_by_patterns_cmd(void)
 {
-	struct dir_struct dir;
+	struct dir_struct dir = DIR_INIT;
 	struct strbuf confirm = STRBUF_INIT;
 	struct strbuf **ignore_list;
 	struct string_list_item *item;
@@ -665,7 +665,6 @@ static int filter_by_patterns_cmd(void)
 		if (!confirm.len)
 			break;
 
-		dir_init(&dir);
 		pl = add_pattern_list(&dir, EXC_CMDL, "manual exclude");
 		ignore_list = strbuf_split_max(&confirm, ' ', 0);
 
@@ -890,7 +889,7 @@ int cmd_clean(int argc, const char **argv, const char *prefix)
 	int ignored_only = 0, config_set = 0, errors = 0, gone = 1;
 	int rm_flags = REMOVE_DIR_KEEP_NESTED_GIT;
 	struct strbuf abs_path = STRBUF_INIT;
-	struct dir_struct dir;
+	struct dir_struct dir = DIR_INIT;
 	struct pathspec pathspec;
 	struct strbuf buf = STRBUF_INIT;
 	struct string_list exclude_list = STRING_LIST_INIT_NODUP;
@@ -921,7 +920,6 @@ int cmd_clean(int argc, const char **argv, const char *prefix)
 	argc = parse_options(argc, argv, prefix, options, builtin_clean_usage,
 			     0);
 
-	dir_init(&dir);
 	if (!interactive && !dry_run && !force) {
 		if (config_set)
 			die(_("clean.requireForce set to true and neither -i, -n, nor -f given; "

builtin/grep.c

@@ -704,10 +704,9 @@ static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
 static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec,
 			  int exc_std, int use_index)
 {
-	struct dir_struct dir;
+	struct dir_struct dir = DIR_INIT;
 	int i, hit = 0;
 
-	dir_init(&dir);
 	if (!use_index)
 		dir.flags |= DIR_NO_GITLINKS;
 	if (exc_std)

builtin/ls-files.c

@@ -608,7 +608,7 @@ int cmd_ls_files(int argc, const char **argv, const char *cmd_prefix)
 {
 	int require_work_tree = 0, show_tag = 0, i;
 	char *max_prefix;
-	struct dir_struct dir;
+	struct dir_struct dir = DIR_INIT;
 	struct pattern_list *pl;
 	struct string_list exclude_list = STRING_LIST_INIT_NODUP;
 	struct option builtin_ls_files_options[] = {
@@ -678,7 +678,6 @@ int cmd_ls_files(int argc, const char **argv, const char *cmd_prefix)
 	if (argc == 2 && !strcmp(argv[1], "-h"))
 		usage_with_options(ls_files_usage, builtin_ls_files_options);
 
-	dir_init(&dir);
 	prefix = cmd_prefix;
 	if (prefix)
 		prefix_len = strlen(prefix);

builtin/stash.c

@@ -991,9 +991,8 @@ static int get_untracked_files(const struct pathspec *ps, int include_untracked,
 {
 	int i;
 	int found = 0;
-	struct dir_struct dir;
+	struct dir_struct dir = DIR_INIT;
 
-	dir_init(&dir);
 	if (include_untracked != INCLUDE_ALL_FILES)
 		setup_standard_excludes(&dir);
 

dir.c

@@ -53,12 +53,6 @@ static enum path_treatment read_directory_recursive(struct dir_struct *dir,
 	int check_only, int stop_at_first_file, const struct pathspec *pathspec);
 static int resolve_dtype(int dtype, struct index_state *istate,
 			 const char *path, int len);
-
-void dir_init(struct dir_struct *dir)
-{
-	memset(dir, 0, sizeof(*dir));
-}
-
 struct dirent *readdir_skip_dot_and_dotdot(DIR *dirp)
 {
 	struct dirent *e;
@@ -3105,6 +3099,7 @@ void dir_clear(struct dir_struct *dir)
 	struct exclude_list_group *group;
 	struct pattern_list *pl;
 	struct exclude_stack *stk;
+	struct dir_struct new = DIR_INIT;
 
 	for (i = EXC_CMDL; i <= EXC_FILE; i++) {
 		group = &dir->exclude_list_group[i];
@@ -3132,7 +3127,7 @@ void dir_clear(struct dir_struct *dir)
 	}
 	strbuf_release(&dir->basebuf);
 
-	dir_init(dir);
+	memcpy(dir, &new, sizeof(*dir));
 }
 
 struct ondisk_untracked_cache {

dir.h

@@ -342,6 +342,8 @@ struct dir_struct {
 	unsigned visited_directories;
 };
 
+#define DIR_INIT { 0 }
+
 struct dirent *readdir_skip_dot_and_dotdot(DIR *dirp);
 
 /*Count the number of slashes for string s*/
@@ -367,8 +369,6 @@ int match_pathspec(struct index_state *istate,
 int report_path_error(const char *ps_matched, const struct pathspec *pathspec);
 int within_depth(const char *name, int namelen, int depth, int max_depth);
 
-void dir_init(struct dir_struct *dir);
-
 int fill_directory(struct dir_struct *dir,
 		   struct index_state *istate,
 		   const struct pathspec *pathspec);

merge.c

@@ -53,7 +53,7 @@ int checkout_fast_forward(struct repository *r,
 	struct unpack_trees_options opts;
 	struct tree_desc t[MAX_UNPACK_TREES];
 	int i, nr_trees = 0;
-	struct dir_struct dir;
+	struct dir_struct dir = DIR_INIT;
 	struct lock_file lock_file = LOCK_INIT;
 
 	refresh_index(r->index, REFRESH_QUIET, NULL, NULL, NULL);
@@ -80,7 +80,6 @@ int checkout_fast_forward(struct repository *r,
 	}
 
 	memset(&opts, 0, sizeof(opts));
-	dir_init(&dir);
 	if (overwrite_ignore) {
 		dir.flags |= DIR_SHOW_IGNORED;
 		setup_standard_excludes(&dir);

wt-status.c

@@ -699,14 +699,13 @@ static void wt_status_collect_changes_initial(struct wt_status *s)
 static void wt_status_collect_untracked(struct wt_status *s)
 {
 	int i;
-	struct dir_struct dir;
+	struct dir_struct dir = DIR_INIT;
 	uint64_t t_begin = getnanotime();
 	struct index_state *istate = s->repo->index;
 
 	if (!s->show_untracked_files)
 		return;
 
-	dir_init(&dir);
 	if (s->show_untracked_files != SHOW_ALL_UNTRACKED_FILES)
 		dir.flags |=
 			DIR_SHOW_OTHER_DIRECTORIES | DIR_HIDE_EMPTY_DIRECTORIES;