OpenEuphoria

Re: Problem calling my C DLL from a IDE created source

• Posted by Robert Craig <rds at RapidEuphoria.com> Mar 08, 2007
• 516 views

Andrew Katz wrote:
> I fixed this as follows:
> 
> The C program is:
> 
> int __stdcall __export _dll_entry( int arg )
> {
> 	return (arg + arg);
> }
> 
> And the change to the EU code is one line:
> 
> entry = define_c_func (dll, "__dll_entry@4", {C_UINT}, C_UINT)
> 
> -----------------
> 
> I do think this is a very strange way of doing things.
> For example, why does not dll_entry by itself work?

Windows dll's and the multiple C calling conventions are 
needlessly complicated and poorly documented, and aren't
fully compatible from one C compiler to the next.
Unfortunately Euphoria has to be able to interface
with these things. I think they add the "@4" part so
the C linker will know how many bytes of arguments
are to be passed.

> It is important to realize that this was just a test case. I have a long C
> procedure which I want to call and not rewrite.

You've won more than half the battle just by getting the interface
to work. What you do inside your C routine is your business
and should be relatively easy.

Regards,
   Rob Craig
   Rapid Deployment Software
   http://www.RapidEuphoria.com