Hello,

I am developing a game and would like to write the core in haskell with haskell also for scripting. I like haskell.

I have the following file to help me do this.

>>> BEGIN FILE

{-# LANGUAGE ScopedTypeVariables #-}

module Plugin.Load where

import Data.Functor

import System.Directory

import GHC

import GHC.Paths

import DynFlags

import Unsafe.Coerce

type ModName = String

type ValName = String

loadPlugin :: FilePath -> ModName -> ValName -> IO a

loadPlugin dir modName value = do

withCurrentDirectory dir $

defaultErrorHandler defaultFatalMessager defaultFlushOut $

runGhc (Just libdir) $ do

dynFlags <- getSessionDynFlags

setSessionDynFlags $ dynamicTooMkDynamicDynFlags $ dynFlags

{ importPaths = [modName] ++ importPaths dynFlags

, hscTarget = HscAsm

, ghcLink = LinkInMemory

, ghcMode = CompManager

}

sequence [guessTarget modName Nothing] >>= setTargets

load LoadAllTargets

setContext [IIDecl $ simpleImportDecl $ mkModuleName modName]

fetched <- compileExpr (modName ++ "." ++ value)

return (unsafeCoerce fetched :: a)

<<< END FILE

The problem is that if I run the function loadPlugin on the same input more than once, GHC barfs. The error I get is:

/usr/bin/ld.gold: error: cannot find -lghc_5

collect2: error: ld returned 1 exit status

`gcc' failed in phase `Linker'. (Exit code: 1)

*** Exception: ExitFailure 1

sometimes it's -lghc_2 or -lghc_13 above. Anyways, it seems like I and/or ghc isn't cleaning up properly after themself and then wants to try to append numbers. Any idea what is causing this and how to fix it?

Thanks,

Matt

PS. is there a better way of doing this using Typeable? I'd rather not unsafeCoerce.