PeterFlake will look how SV handles these, as he (obviously) can not remember such specific details.
The FFI/DPI interface will NOT be part of VHPI, but a separate interface. However, data type conversions, specially of simple types, will be shared. That is, section 22.2 of the current LRM.
We discussed about variables of modes `out` or `inout` and about passing signals. These, along with supporting `wait` statements in foreign functions does require a further thought.
The first version might just not support either `wait` statements or signals, but only variables or constants. However, we should consider other features too, so we avoid future breaking changes.
PeterLadow proposed all symbols to be exported and imported automatically, through name mangling, as in C++.