GHC.Cabal

One of the challenges of using the GHC API for external tooling is handling integration with Cabal. This library provides a simple interface for configuring GHC's DynFlags as Cabal would have, allowing seamless tooling use on Cabal projects.

A typical usage might look like,

import GHC
import qualified GHC.Paths
import qualified Distribution.Verbosity as Verbosity
import GHC.Cabal

main = runGhc (Just GHC.Paths.libdir) $ do
    dflags <- GHC.getSessionDynFlags
    -- Use default DynFlags if we aren't in a Cabal project
    dflags' <- fromMaybe dflags <$> liftIO (initCabalDynFlags Verbosity.normal dflags)
    GHC.setSessionDynFlags dflags'

    -- Standard GHC API usage goes here

Initializing GHC DynFlags for Cabal packages

initCabalDynFlags :: Verbosity -> DynFlags -> IO (Maybe DynFlags)

Modify a set of DynFlags to match what Cabal would produce.