[Haskell-cafe] using a win32 dll (Happy too soon)

[Kees Bleijenberg]

Unfortunatly the proposed solutions didn't work after all (It worked once, I
think, but.)

 

Here again the problem:

glasPng.dll is a Delphi dll with the function getPngVersion in it. Calling
convention  is stdCall. I want to use this dll. The code:

{-# LANGUAGE ForeignFunctionInterface #-}

module Main(

      main

)

 

where

import Control.Monad

import Foreign.C

import Foreign.Marshal.Alloc

import Foreign.Marshal.Array

import System.Win32.Types

 

foreign import stdcall "getPngVersion"  getPngDllVersion :: IO CString

 

main :: IO ()

main = do

         s <- getPngDllVersion

         putStrLn (show s)

 

glasPng.dll is in the Windows path (I've checked it). 

If I compile with ghc --make testGlasPng.hs -lglasPng I get: ..\ld.exe:
cannot find -lglasPng. Collect 2: ld returned 1 exit status.

Ld can't find lglasPng (with the l in front, does it trim the l?). Why? Okay
I try

ghc --make testGlasPng.hs -L<path to glasPng.dll> I get:

testGlasPng.o: fake: (.text + 0x82) :undefined reference to
'getPngVersion at 0'. I think it has found  the dll, but it complains the
function is not in the dll. But TDump and Dll export viewer say
getPngVersion is in the dll.

 

I run ghc on a 64 bits computer. The dll is 32 bits. Is that the problem?

 

What can I do?

Kees

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