__ISO_C_VISIBLE is already defined on FreeBSD. By default, it has a value of 2011. This causes a lot of compiler warnings.
@@ -57,7 +57,9 @@ extern const union __nan_un {
//VBS begin
#define __MATH_BUILTIN_CONSTANTS
#define __MATH_BUILTIN_RELOPS
+#ifndef __ISO_C_VISIBLE
#define __ISO_C_VISIBLE 1999
+#endif
//VBS end
#ifdef __MATH_BUILTIN_CONSTANTS