--- Libc/Libc-763.13/include/secure/_stdio.h
+++ Libc/Libc-1534.40.2/include/secure/_stdio.h
@@ -32,46 +32,59 @@
 
 #if _USE_FORTIFY_LEVEL > 0
 
+#ifndef __has_builtin
+#define _undef__has_builtin
+#define __has_builtin(x) 0
+#endif
+
+#ifndef UNIFDEF_DRIVERKIT
+/* sprintf, vsprintf, snprintf, vsnprintf */
+#if __has_builtin(__builtin___sprintf_chk) || defined(__GNUC__)
+extern int __sprintf_chk (char * __restrict, int, size_t,
+			  const char * __restrict, ...);
+
 #undef sprintf
-#undef vsprintf
+#define sprintf(str, ...) \
+  __builtin___sprintf_chk (str, 0, __darwin_obsz(str), __VA_ARGS__)
+#endif
+#endif /* UNIFDEF_DRIVERKIT */
 
 #if __DARWIN_C_LEVEL >= 200112L
+#if __has_builtin(__builtin___snprintf_chk) || defined(__GNUC__)
+extern int __snprintf_chk (char * __restrict, size_t, int, size_t,
+			   const char * __restrict, ...);
+
 #undef snprintf
-#undef vsnprintf
+#define snprintf(str, len, ...) \
+  __builtin___snprintf_chk (str, len, 0, __darwin_obsz(str), __VA_ARGS__)
 #endif
 
-/* sprintf, vsprintf, snprintf, vsnprintf */
+#ifndef UNIFDEF_DRIVERKIT
+#if __has_builtin(__builtin___vsprintf_chk) || defined(__GNUC__)
+extern int __vsprintf_chk (char * __restrict, int, size_t,
+			   const char * __restrict, va_list);
 
-extern int __sprintf_chk (char * __restrict, int, size_t,
-			  const char * __restrict, ...)
-  __DARWIN_LDBL_COMPAT (__sprintf_chk);
-
-#define sprintf(str, ...) \
-  __builtin___sprintf_chk (str, 0, __darwin_obsz(str), __VA_ARGS__)
-
-extern int __snprintf_chk (char * __restrict, size_t, int, size_t,
-			   const char * __restrict, ...)
-  __DARWIN_LDBL_COMPAT (__snprintf_chk);
-
-#if __DARWIN_C_LEVEL >= 200112L
-#define snprintf(str, len, ...) \
-  __builtin___snprintf_chk (str, len, 0, __darwin_obsz(str), __VA_ARGS__)
-
-extern int __vsprintf_chk (char * __restrict, int, size_t,
-			   const char * __restrict, va_list)
-  __DARWIN_LDBL_COMPAT (__vsprintf_chk);
-
+#undef vsprintf
 #define vsprintf(str, format, ap) \
   __builtin___vsprintf_chk (str, 0, __darwin_obsz(str), format, ap)
+#endif
+#endif /* UNIFDEF_DRIVERKIT */
 
+#if __has_builtin(__builtin___vsnprintf_chk) || defined(__GNUC__)
 extern int __vsnprintf_chk (char * __restrict, size_t, int, size_t,
-			    const char * __restrict, va_list)
-  __DARWIN_LDBL_COMPAT (__vsnprintf_chk);
+			    const char * __restrict, va_list);
 
+#undef vsnprintf
 #define vsnprintf(str, len, format, ap) \
   __builtin___vsnprintf_chk (str, len, 0, __darwin_obsz(str), format, ap)
 #endif
 
+#endif /* __DARWIN_C_LEVEL >= 200112L */
+
+#ifdef _undef__has_builtin
+#undef _undef__has_builtin
+#undef __has_builtin
 #endif
 
-#endif
+#endif /* _USE_FORTIFY_LEVEL > 0 */
+#endif /* _SECURE__STDIO_H_ */