kernel: define READ/WRITE_ONCE using typeof() for C sources

include/socks/compiler.h

@@ -1,9 +1,6 @@
 #ifndef SOCKS_COMPILER_H_
 #define SOCKS_COMPILER_H_
 
-#define READ_ONCE(t, p) (*((const volatile t *)&(p)))
-#define WRITE_ONCE(t, p, v) *(volatile t *)&(p) = (v)
-
 #ifdef __cplusplus
 template <typename T>
 T read_once(const volatile T *ptr)
@@ -16,6 +13,11 @@ void write_once(volatile T *ptr, T value)
 {
 	*ptr = value;
 }
+#else
+
+#define READ_ONCE(p) (*((const volatile typeof(p) *)&(p)))
+#define WRITE_ONCE(p, v) *(volatile typeof(p) *)&(p) = (v)
+
 #endif
 
 #undef __used