Calling var_args functions from with Wrapper

Hello!

I am trying to call the function vsnprintf from within a wrapper for vnsprintf using the I_WRAP and CALL_FN macros provided by Valgrind.

However, all of the CALL_FN macros only take longs as parameters. vsnprintf takes a va_list struct as one of its parameters.

Is there a way to use call functions that take va_lists (or any sort of struct) as parameters from inside a wrapper?

Best Regards,
Austin Gadient