split out wchar_t from stddef header

include/stddef.h

@@ -3,16 +3,7 @@
 
 // wchar_t should come before NULL and size_t
 // according to comment in wchar cbindgen
-#ifndef _WCHAR_T
-#define _WCHAR_T
-#ifndef __cplusplus
-    #ifndef __WCHAR_TYPE__
-        #define __WCHAR_TYPE__ int
-    #endif
-    typedef __WCHAR_TYPE__ wchar_t;
-#endif // __cplusplus
-#endif // _WCHAR_T
-
+#include <bits/wchar-t.h>
 #include <bits/size-t.h>
 #include <bits/null.h>
 

src/header/bits_wchar-t/cbindgen.toml

@@ -0,0 +1,18 @@
+# POSIX header spec: https://pubs.opengroup.org/onlinepubs/9799919799/basedefs/stddef.h.html
+#
+# This type is split out to prevent importing all of stddef.h into inttypes.h
+include_guard = "_RELIBC_BITS_WCHAR_T_H"
+after_includes = """
+#ifndef _WCHAR_T
+#define _WCHAR_T
+#ifndef __cplusplus
+    #ifndef __WCHAR_TYPE__
+        #define __WCHAR_TYPE__ int
+    #endif
+    typedef __WCHAR_TYPE__ wchar_t;
+#endif // __cplusplus
+#endif // _WCHAR_T
+"""
+language = "C"
+no_includes = true
+cpp_compat = true

src/header/bits_wchar-t/mod.rs

@@ -0,0 +1 @@
+// `wchar_t` is defined in cbindgen

src/header/inttypes/cbindgen.toml

@@ -3,10 +3,10 @@
 # Spec quotations relating to includes:
 # - "The <inttypes.h> header shall include the <stdint.h> header."
 # - "wchar_t As described in <stddef.h>."
-#
-# TODO possibly split out wchar_t to avoid including all of stddef.h
-# stddef.h also currently includes stdint.h but shouldn't according to the spec
-sys_includes = ["stdint.h", "stddef.h"]
+sys_includes = ["stdint.h"]
+after_includes = """
+#include <bits/wchar-t.h> // for wchar_t from stddef.h
+"""
 include_guard = "_RELIBC_INTTYPES_H"
 trailer = """
 #ifndef _RELIBC_BITS_INTTYPES_H

src/header/mod.rs

@@ -58,6 +58,8 @@ pub mod bits_timeval;
 pub mod bits_uid_t;
 #[path = "bits_useconds-t/mod.rs"]
 pub mod bits_useconds_t;
+#[path = "bits_wchar-t/mod.rs"]
+pub mod bits_wchar_t;
 pub mod bits_winsize;
 // complex.h implemented in C (currently through openlibm)
 pub mod cpio;