diff --git a/apply.c b/apply.c
index 853d3ed385..44bc31d6eb 100644
--- a/apply.c
+++ b/apply.c
@@ -101,9 +101,9 @@ int init_apply_state(struct apply_state *state,
 	state->ws_error_action = warn_on_ws_error;
 	state->ws_ignore_action = ignore_ws_none;
 	state->linenr = 1;
-	string_list_init(&state->fn_table, 0);
-	string_list_init(&state->limit_by_name, 0);
-	string_list_init(&state->symlink_changes, 0);
+	string_list_init_nodup(&state->fn_table);
+	string_list_init_nodup(&state->limit_by_name);
+	string_list_init_nodup(&state->symlink_changes);
 	strbuf_init(&state->root, 0);
 
 	git_apply_config();
diff --git a/archive.c b/archive.c
index ff2bb54f62..3c266d1d7b 100644
--- a/archive.c
+++ b/archive.c
@@ -645,7 +645,7 @@ int write_archive(int argc, const char **argv, const char *prefix,
 	args.pretty_ctx = &ctx;
 	args.repo = repo;
 	args.prefix = prefix;
-	string_list_init(&args.extra_files, 1);
+	string_list_init_dup(&args.extra_files);
 	argc = parse_archive_args(argc, argv, &ar, &args, name_hint, remote);
 	if (!startup_info->have_repository) {
 		/*
diff --git a/builtin/add.c b/builtin/add.c
index b773b5a499..09e684585d 100644
--- a/builtin/add.c
+++ b/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;
 
diff --git a/builtin/check-ignore.c b/builtin/check-ignore.c
index 81234552b7..2191256965 100644
--- a/builtin/check-ignore.c
+++ b/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) {
diff --git a/builtin/clean.c b/builtin/clean.c
index 4944cf440b..98a2860409 100644
--- a/builtin/clean.c
+++ b/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; "
diff --git a/builtin/grep.c b/builtin/grep.c
index ab8822e68f..7d2f8e5adb 100644
--- a/builtin/grep.c
+++ b/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)
diff --git a/builtin/ls-files.c b/builtin/ls-files.c
index 45cc3b23dd..29a26ad8ae 100644
--- a/builtin/ls-files.c
+++ b/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);
diff --git a/builtin/stash.c b/builtin/stash.c
index 9c72e4b125..8f42360ca9 100644
--- a/builtin/stash.c
+++ b/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);
 
diff --git a/config.c b/config.c
index 55313fcf44..c4dcb40b47 100644
--- a/config.c
+++ b/config.c
@@ -2073,7 +2073,7 @@ static int configset_add_value(struct config_set *cs, const char *key, const cha
 		e = xmalloc(sizeof(*e));
 		hashmap_entry_init(&e->ent, strhash(key));
 		e->key = xstrdup(key);
-		string_list_init(&e->value_list, 1);
+		string_list_init_dup(&e->value_list);
 		hashmap_add(&cs->config_hash, &e->ent);
 	}
 	si = string_list_append_nodup(&e->value_list, xstrdup_or_null(value));
diff --git a/credential.c b/credential.c
index e5202fbef2..3c05c7c669 100644
--- a/credential.c
+++ b/credential.c
@@ -10,8 +10,8 @@
 
 void credential_init(struct credential *c)
 {
-	memset(c, 0, sizeof(*c));
-	c->helpers.strdup_strings = 1;
+	struct credential blank = CREDENTIAL_INIT;
+	memcpy(c, &blank, sizeof(*c));
 }
 
 void credential_clear(struct credential *c)
diff --git a/credential.h b/credential.h
index c0e17e3554..f430e77fea 100644
--- a/credential.h
+++ b/credential.h
@@ -128,7 +128,9 @@ struct credential {
 	char *path;
 };
 
-#define CREDENTIAL_INIT { STRING_LIST_INIT_DUP }
+#define CREDENTIAL_INIT { \
+	.helpers = STRING_LIST_INIT_DUP, \
+}
 
 /* Initialize a credential structure, setting all fields to empty. */
 void credential_init(struct credential *);
diff --git a/dir.c b/dir.c
index ebe5ec046e..313e932459 100644
--- a/dir.c
+++ b/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 {
diff --git a/dir.h b/dir.h
index e3db9b9ec6..8d0ddd8f18 100644
--- a/dir.h
+++ b/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);
diff --git a/entry.c b/entry.c
index 711ee0693c..125fabdbd5 100644
--- a/entry.c
+++ b/entry.c
@@ -143,8 +143,8 @@ void enable_delayed_checkout(struct checkout *state)
 	if (!state->delayed_checkout) {
 		state->delayed_checkout = xmalloc(sizeof(*state->delayed_checkout));
 		state->delayed_checkout->state = CE_CAN_DELAY;
-		string_list_init(&state->delayed_checkout->filters, 0);
-		string_list_init(&state->delayed_checkout->paths, 0);
+		string_list_init_nodup(&state->delayed_checkout->filters);
+		string_list_init_nodup(&state->delayed_checkout->paths);
 	}
 }
 
diff --git a/json-writer.c b/json-writer.c
index aadb9dbddc..f1cfd8fa8c 100644
--- a/json-writer.c
+++ b/json-writer.c
@@ -3,10 +3,8 @@
 
 void jw_init(struct json_writer *jw)
 {
-	strbuf_init(&jw->json, 0);
-	strbuf_init(&jw->open_stack, 0);
-	jw->need_comma = 0;
-	jw->pretty = 0;
+	struct json_writer blank = JSON_WRITER_INIT;
+	memcpy(jw, &blank, sizeof(*jw));;
 }
 
 void jw_release(struct json_writer *jw)
diff --git a/json-writer.h b/json-writer.h
index 83906b09c1..209355e0f1 100644
--- a/json-writer.h
+++ b/json-writer.h
@@ -64,7 +64,10 @@ struct json_writer
 	unsigned int pretty:1;
 };
 
-#define JSON_WRITER_INIT { STRBUF_INIT, STRBUF_INIT, 0, 0 }
+#define JSON_WRITER_INIT { \
+	.json = STRBUF_INIT, \
+	.open_stack = STRBUF_INIT, \
+}
 
 void jw_init(struct json_writer *jw);
 void jw_release(struct json_writer *jw);
diff --git a/merge-ort.c b/merge-ort.c
index ddba1db2ef..8cfa0ccd3c 100644
--- a/merge-ort.c
+++ b/merge-ort.c
@@ -1840,7 +1840,7 @@ static void compute_collisions(struct strmap *collisions,
 			free(new_path);
 		} else {
 			CALLOC_ARRAY(collision_info, 1);
-			string_list_init(&collision_info->source_files, 0);
+			string_list_init_nodup(&collision_info->source_files);
 			strmap_put(collisions, new_path, collision_info);
 		}
 		string_list_insert(&collision_info->source_files,
@@ -4030,7 +4030,7 @@ static void merge_start(struct merge_options *opt, struct merge_result *result)
 	 */
 	strmap_init_with_options(&opt->priv->paths, NULL, 0);
 	strmap_init_with_options(&opt->priv->conflicted, NULL, 0);
-	string_list_init(&opt->priv->paths_to_free, 0);
+	string_list_init_nodup(&opt->priv->paths_to_free);
 
 	/*
 	 * keys & strbufs in output will sometimes need to outlive "paths",
diff --git a/merge-recursive.c b/merge-recursive.c
index 9a8a39f014..a67bf2acfa 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -121,7 +121,7 @@ static void dir_rename_entry_init(struct dir_rename_entry *entry,
 	entry->dir = directory;
 	entry->non_unique_new_dir = 0;
 	strbuf_init(&entry->new_dir, 0);
-	string_list_init(&entry->possible_new_dirs, 0);
+	string_list_init_nodup(&entry->possible_new_dirs);
 }
 
 struct collision_entry {
@@ -3710,7 +3710,7 @@ static int merge_start(struct merge_options *opt, struct tree *head)
 	}
 
 	CALLOC_ARRAY(opt->priv, 1);
-	string_list_init(&opt->priv->df_conflict_file_set, 1);
+	string_list_init_dup(&opt->priv->df_conflict_file_set);
 	return 0;
 }
 
diff --git a/merge.c b/merge.c
index 5fb88af102..6e736881d9 100644
--- a/merge.c
+++ b/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);
diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index 66cb90c79e..f8aa97d799 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -1425,7 +1425,7 @@ static int packed_transaction_prepare(struct ref_store *ref_store,
 	 */
 
 	CALLOC_ARRAY(data, 1);
-	string_list_init(&data->updates, 0);
+	string_list_init_nodup(&data->updates);
 
 	transaction->backend_data = data;
 
diff --git a/run-command.c b/run-command.c
index be6bc128cd..8750df16d8 100644
--- a/run-command.c
+++ b/run-command.c
@@ -11,9 +11,8 @@
 
 void child_process_init(struct child_process *child)
 {
-	memset(child, 0, sizeof(*child));
-	strvec_init(&child->args);
-	strvec_init(&child->env_array);
+	struct child_process blank = CHILD_PROCESS_INIT;
+	memcpy(child, &blank, sizeof(*child));
 }
 
 void child_process_clear(struct child_process *child)
diff --git a/run-command.h b/run-command.h
index d08414a92e..62a922d23f 100644
--- a/run-command.h
+++ b/run-command.h
@@ -141,7 +141,10 @@ struct child_process {
 	void *clean_on_exit_handler_cbdata;
 };
 
-#define CHILD_PROCESS_INIT { NULL, STRVEC_INIT, STRVEC_INIT }
+#define CHILD_PROCESS_INIT { \
+	.args = STRVEC_INIT, \
+	.env_array = STRVEC_INIT, \
+}
 
 /**
  * The functions: child_process_init, start_command, finish_command,
diff --git a/strbuf.c b/strbuf.c
index 4df30b4549..c8a5789694 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -52,8 +52,8 @@ char strbuf_slopbuf[1];
 
 void strbuf_init(struct strbuf *sb, size_t hint)
 {
-	sb->alloc = sb->len = 0;
-	sb->buf = strbuf_slopbuf;
+	struct strbuf blank = STRBUF_INIT;
+	memcpy(sb, &blank, sizeof(*sb));
 	if (hint)
 		strbuf_grow(sb, hint);
 }
diff --git a/string-list.c b/string-list.c
index a917955fbd..43576ad126 100644
--- a/string-list.c
+++ b/string-list.c
@@ -1,10 +1,24 @@
 #include "cache.h"
 #include "string-list.h"
 
+void string_list_init_nodup(struct string_list *list)
+{
+	struct string_list blank = STRING_LIST_INIT_NODUP;
+	memcpy(list, &blank, sizeof(*list));
+}
+
+void string_list_init_dup(struct string_list *list)
+{
+	struct string_list blank = STRING_LIST_INIT_DUP;
+	memcpy(list, &blank, sizeof(*list));
+}
+
 void string_list_init(struct string_list *list, int strdup_strings)
 {
-	memset(list, 0, sizeof(*list));
-	list->strdup_strings = strdup_strings;
+	if (strdup_strings)
+		string_list_init_dup(list);
+	else
+		string_list_init_nodup(list);
 }
 
 /* if there is no exact match, point to the index where the entry could be
diff --git a/string-list.h b/string-list.h
index 6c5d274126..0d6b469239 100644
--- a/string-list.h
+++ b/string-list.h
@@ -91,14 +91,21 @@ struct string_list {
 	compare_strings_fn cmp; /* NULL uses strcmp() */
 };
 
-#define STRING_LIST_INIT_NODUP { NULL, 0, 0, 0, NULL }
-#define STRING_LIST_INIT_DUP   { NULL, 0, 0, 1, NULL }
+#define STRING_LIST_INIT_NODUP { 0 }
+#define STRING_LIST_INIT_DUP   { .strdup_strings = 1 }
 
 /* General functions which work with both sorted and unsorted lists. */
 
 /**
- * Initialize the members of the string_list, set `strdup_strings`
- * member according to the value of the second parameter.
+ * Initialize the members of a string_list pointer in the same way as
+ * the corresponding `STRING_LIST_INIT_NODUP` and
+ * `STRING_LIST_INIT_DUP` macros.
+ */
+void string_list_init_nodup(struct string_list *list);
+void string_list_init_dup(struct string_list *list);
+
+/**
+ * TODO remove: For compatibility with any in-flight older API users
  */
 void string_list_init(struct string_list *list, int strdup_strings);
 
diff --git a/strmap.c b/strmap.c
index 4fb9f6100e..ee48635708 100644
--- a/strmap.c
+++ b/strmap.c
@@ -25,7 +25,8 @@ static struct strmap_entry *find_strmap_entry(struct strmap *map,
 
 void strmap_init(struct strmap *map)
 {
-	strmap_init_with_options(map, NULL, 1);
+	struct strmap blank = STRMAP_INIT;
+	memcpy(map, &blank, sizeof(*map));
 }
 
 void strmap_init_with_options(struct strmap *map,
diff --git a/strvec.c b/strvec.c
index 21dce0a7a4..61a76ce6cb 100644
--- a/strvec.c
+++ b/strvec.c
@@ -6,9 +6,8 @@ const char *empty_strvec[] = { NULL };
 
 void strvec_init(struct strvec *array)
 {
-	array->v = empty_strvec;
-	array->nr = 0;
-	array->alloc = 0;
+	struct strvec blank = STRVEC_INIT;
+	memcpy(array, &blank, sizeof(*array));
 }
 
 static void strvec_push_nodup(struct strvec *array, const char *value)
diff --git a/transport.c b/transport.c
index 745ffa2247..17e9629710 100644
--- a/transport.c
+++ b/transport.c
@@ -1055,7 +1055,7 @@ struct transport *transport_get(struct remote *remote, const char *url)
 	struct transport *ret = xcalloc(1, sizeof(*ret));
 
 	ret->progress = isatty(2);
-	string_list_init(&ret->pack_lockfiles, 1);
+	string_list_init_dup(&ret->pack_lockfiles);
 
 	if (!remote)
 		BUG("No remote provided to transport_get()");
diff --git a/wt-status.c b/wt-status.c
index 42b6735716..b5a3e1cc25 100644
--- a/wt-status.c
+++ b/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;