It should receive one file as an input, but be able to generate multiple modules with the names of its own choosing. And I want the resulting modules to be added to all build steps automatically. So it should looks approximately like this:

data SmartPreProcessor = SmartPreProcessor {
    platformIndependent :: Bool,
    runPreProcessor :: (FilePath, FilePath) -- Location of the source file relative to a base dir
                    -> Verbosity            -- verbosity
                    -> FilePath             -- output base dir
                    -> IO [FilePath]        -- output sources files. Should exit if the preprocessor fails
}