A simple frontend plugin that prints all modules of a project in topological order

GhcSort.hs

module GhcSort where

import GHC
import GhcPlugins
import DriverPhases

import Control.Monad
import Data.List
import Data.Maybe
import System.FilePath
import Data.Graph

frontendPlugin :: FrontendPlugin
frontendPlugin = defaultFrontendPlugin {
        frontend = doDiff
    }

doDiff :: [String] -> [(String, Maybe Phase)] -> Ghc ()
doDiff _args srcs = do
    -- API infelicity: we should be CompManager by default...
    dflags <- getSessionDynFlags
    _ <- setSessionDynFlags dflags { ghcMode = CompManager }

    let (hs_srcs, _non_hs_srcs) = partition isHaskellishTarget srcs

    targets <- mapM (uncurry guessTarget) hs_srcs
    setTargets targets
    mod_graph <- depanal [] False

    let full_mg :: [SCC ModSummary]
        full_mg = topSortModuleGraph False mod_graph Nothing

    forM_ (flattenSCCs full_mg) $ \ms ->
        liftIO $ putStrLn (normalise (fromJust (ml_hs_file (ms_location ms))))
    return ()