AFAIK this warning is about Perl prototypes for XS routines, which usually do NOT make a more Perl-friendly API :-)

To disable these warnings put

PROTOTYPES: DISABLE
[download]

On the line after your MODULE declaration in the xs file(s).

Anyway, you probably have some manual work to do to make the interface more perl-friendly, possibly by taking the h2xs generated code as a starting point. You could also try to make Perl wrappers around the XS code if you feel more comfortable with Perl than with C.

For a friendly introduction to XS and extending Perl in general, I can also recommend the Manning book "Extending and Embedding Perl".

HTH,
Joost.