I am experimenting creating a dll for firebird - thought I would try
something simple. I created one where I just took a parameter and
returned it, and it worked fine. However, when I created a minor
change, such as adding to parameters together and returning that, I
consistently get an incorrect return of 0.

The strange thing is that I can use the same dll in other languages
and it returns the parameters properly added together. So, I am a bit
lost as to what is going wrong in Firebird.

I am using Firebird 2.0 on Windows XP using wx-Dev-C++ ver. 6.9 to
create a C dll. Any help/insight would be appreciated. Following is
the code. Thanks!



testdll.h

#ifndef _TESTDLL_H_
#define _TESTDLL_H_

#if BUILDING_DLL
# define DLLIMPORT __declspec (dllexport)
#else /* Not BUILDING_DLL */
# define DLLIMPORT __declspec (dllimport)
#endif /* Not BUILDING_DLL */


DLLIMPORT int addfunc( int, int );


#endif /* _TESTDLL_H_ */





testdll.c

#include "testdll.h"

DLLIMPORT int addfunc( int a, int b )
{
return a + b;
}





testdll.sql

DECLARE EXTERNAL FUNCTION addfunc
INTEGER, INTEGER
RETURNS INTEGER
ENTRY_POINT 'addfunc' MODULE_NAME 'testdll';