Compiling base with custom compilation script

[Simon Marlow]

On 01/09/2010 12:08, Victor Nazarov wrote:
> I have some custom compilation script that uses GHC API
> The aim is to extract some info from every module in dependency graph
> and to write this information to the file lying near module-file.
> Script goes like this:
>
> main :: IO ()
> main =
>    do args<- getArgs
>       defaultErrorHandler defaultDynFlags $ runGhc (Just libdir) $
>         do sdflags<- getSessionDynFlags
>            (dflags, fileargs', _)<- parseDynamicFlags sdflags (map noLoc args)
>            when (null fileargs') $ ghcError (UsageError "No input files.")
>            _<- setSessionDynFlags dflags
>            let fileargs = map unLoc fileargs'
>            targets<- mapM (\x ->  guessTarget x Nothing) fileargs
>            setTargets targets
>            mgraph<- depanal [] False
>            let files = filter (not . isSuffixOf "boot")
>                        . map (extractPath . ms_location) $ mgraph
>                extractPath l = fromMaybe (ml_hi_file l) (ml_hs_file l)
>            setTargets []
>            flip mapM_ files $ \file ->
>              do core<- compileToCoreSimplified file
>                 HscTypes.liftIO $
>                      let info = show (generateInfo core)
>                          fp = replaceExtension file ".info"
>                      putStrLn $ "Writing " ++ fp
>                      writeFile fp program
>
> The problem is processing base-4 package. I'd like to run something like:
>
> $ cd base-4.2.0.1
> $ compiler -fglasgow-exts -cpp -package-name base -I./include Prelude.hs
>
> and to receive Prelude.info and .info files for every other modules
> that prelude depends on.
>
> At first I've got errors like missing .h file. I've downloaded GHC
> source distribution and get
> missing headers from GHC.
>
> But now I get errors like "trying to load Prelude module which is not
> loadable". I don't remember the exact text
> and I have no access to my developing-machine. I think it's caused by
> circular dependencies between modules.
> And I think my compilation script is not quite correct for this case.
> What do you think?

There are some problems with compiling the base package independently of 
a GHC build, for some details see here:

   http://hackage.haskell.org/trac/ghc/ticket/3103

in general, though, you should check what flags Cabal is passing to GHC 
to see how to compile a package.  Try "cabal build -v" and grab the GHC 
command line.

Cheers,
	Simon