-# ifdef HAVE_INLINE
-# ifdef __GNUC__
-# ifdef DONT_EXTERN_INLINE_FUNCTIONS
-# define INLINE inline
-# else
-# define INLINE extern inline
-# endif
-# else
-# define INLINE static inline
-# endif /* __GNUC__ */
-# else
-# define INLINE static
-# endif /* HAVE_INLINE */
-#endif /* not C++ */
-#endif /* C code */
+#if defined (__cplusplus) || ! defined (__GNUC__)
+# define INLINE_HEADER inline static
+#elif defined (DONT_EXTERN_INLINE_HEADER_FUNCTIONS)
+# define INLINE_HEADER inline
+#else
+# define INLINE_HEADER inline extern
+#endif