[Haskell-cafe] Re: problems with hs-plugins load-eval (possible bug)

[Alberto G. Corona]

The duplicate definition error appears when I compile Main.hs and execute
it. But when I run it with runghc the behaviour is different.  It works
well:
> runghc Main.hs
3

Any idea? is this a bug of hs-plugins? it is just something expected??

2008/12/6 Alberto G. Corona <agocorona at gmail.com>

> I have a web server which load server extensions. these extensions
> eval-uate configuration files that contains code (user-editable workflow
> descriptions). The problem is that I need common definitions (inside
> imported modules)  for the extensions and for the configuration files. This
> is not permitted by ha-plugins.
>
> The minimal code example are the  files below. main loads eval.hs , that
> evaluate a expression. The common definitions are in Include.hs. The error
> is:
>
> *GHCi runtime linker: fatal error: I found a duplicate definition for
> symbol
>    Include_sum1_srt
> whilst processing object file
>    /home/magocoal/haskell/devel/votesWorkflow/src/unused/tests/Include.o
>
> This could be caused by:
>    * Loading two different object files which export the same symbol
>    * Specifying the same object file twice on the GHCi command line
>    * An incorrect `package.conf' entry, causing some object to be
>      loaded twice.
> GHCi cannot safely continue in this situation.  Exiting now.  Sorry.
> *
>
>
> **
> Do you kno how to solve the problem while maintaining the functionality?
>
> -------Include.hs-------
> module Include where
>
> sum [x,y]= x+y
>
>
> ------Main.hs-----
> module Main
> where
>
> import Include
> import System.Plugins
>
> main= do
>       s <-loadExec "eval.o" "mainc"
>       print s
>
> loadExec:: String-> String->IO String
> loadExec file method = do
>
>                mv <- load file ["."] [] method
>                case mv of
>                 LoadSuccess mod v ->    v :: IO String
>                 LoadFailure msg   ->    return $ concat msg
>
>
>
> ------------Eval.hs--------
>
> module Eval(mainc) where
> import System.IO.Unsafe
> import System.Eval.Haskell
>
> mainc= do  i <- unsafeEval_ "sum1 [1,2]" ["Include"] [] []["."] ::  IO
> (Either  [String]  Int)
>            return $ show i
>
>
>
>
>
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