ghc-mod/Utils.hs
Daniel Gröber 82bb0090c0 Refactoring to use cabal-helper-wrapper
This turned out to be quite involved but save for this huge commit it's
actually quite awesome and squashes quite a few bugs and nasty
problems (hopefully). Most importantly we now have native cabal
component support without the user having to do anything to get it!

To do this we traverse imports starting from each component's
entrypoints (library modules or Main source file for executables) and
use this information to find which component's options each module will
build with. Under the assumption that these modules have to build with
every component they're used in we can now just pick one.

Quite a few internal assumptions have been invalidated by this
change. Most importantly the runGhcModT* family of cuntions now change
the current working directory to `cradleRootDir`.
2015-03-05 17:35:24 +01:00

37 lines
843 B
Haskell

{-# LANGUAGE CPP #-}
module Utils where
import Control.Monad
import Control.Applicative
import Data.Traversable
import System.Directory
#if MIN_VERSION_directory(1,2,0)
import Data.Time (UTCTime)
#else
import System.Time (ClockTime)
#endif
#if MIN_VERSION_directory(1,2,0)
type ModTime = UTCTime
#else
type ModTime = ClockTime
#endif
data TimedFile = TimedFile FilePath ModTime deriving (Eq, Show)
instance Ord TimedFile where
compare (TimedFile _ a) (TimedFile _ b) = compare a b
timeFile :: FilePath -> IO TimedFile
timeFile f = TimedFile <$> pure f <*> getModificationTime f
mightExist :: FilePath -> IO (Maybe FilePath)
mightExist f = do
exists <- doesFileExist f
return $ if exists then (Just f) else (Nothing)
timeMaybe :: FilePath -> IO (Maybe TimedFile)
timeMaybe f = do
join $ (timeFile `traverse`) <$> mightExist f