From: Ben Giddings <bg-rubytalk@...>
Date: 2005-03-24T06:26:19+09:00
Subject: Re: Stack, Struct and DL

Eric Hodel wrote:
> You'll have to teach DL what type FOO is.  Unfortunately, DL doesn't 
> barf on you in a friendly way when it can't recognize a type.

Nicely phrased.  ;)

>> [ ------ foo.rb ------ ]
>>
>> require 'dl/import'
>> require 'dl/struct'
>>
>> module Foo
>>     extend DL::Importable
>>     dlload 'foo.dylib'
> 
> 
>     typealias "FOO", "void *"
> 
> Something like this should do it.  (Yeah, void * is probably the wrong 
> type, see dl/types for what types dl knows about.)

Actually, "void *" is probably right.  When I wrapped my DLL using 
Ruby/DL I just used "void *" whenever I came across a type that I hadn't 
taught DL about.  That seemed to do the trick for me.

Also (I'm no DLL expert or anything) but with GCC I think you have to 
specify position independent code (-fPIC) and some other nifty things. 
Make sure the problem is a DL problem, not a problem with the original DLL.

Ben