ghc-mod/core/Language/Haskell/GhcMod/Monad.hs
2017-03-07 00:25:46 +01:00

149 lines
4.9 KiB
Haskell

-- ghc-mod: Happy Haskell Hacking
-- Copyright (C) 2015 Daniel Gröber <dxld ÄT darkboxed DOT org>
--
-- This program is free software: you can redistribute it and/or modify
-- it under the terms of the GNU Affero General Public License as published by
-- the Free Software Foundation, either version 3 of the License, or
-- (at your option) any later version.
--
-- This program is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-- GNU Affero General Public License for more details.
--
-- You should have received a copy of the GNU Affero General Public License
-- along with this program. If not, see <http://www.gnu.org/licenses/>.
{-# LANGUAGE CPP #-}
module Language.Haskell.GhcMod.Monad (
runGmOutT
, runGmOutT'
, runGhcModT
, runGhcModT'
, hoistGhcModT
, runGmlT
, runGmlT'
, runGmlTWith
, runGmPkgGhc
, withGhcModEnv
, withGhcModEnv'
, module Language.Haskell.GhcMod.Monad.Types
) where
import Language.Haskell.GhcMod.Types
import Language.Haskell.GhcMod.Monad.Types
import Language.Haskell.GhcMod.Error
import Language.Haskell.GhcMod.Logging
import Language.Haskell.GhcMod.Cradle
import Language.Haskell.GhcMod.Target
import Language.Haskell.GhcMod.Output
import Control.Arrow (first)
import Control.Applicative
import Control.Concurrent
import Control.Monad.Reader (runReaderT)
import Control.Monad.State.Strict (runStateT)
import Control.Monad.Trans.Journal (runJournalT)
import Exception
import System.Directory
import System.IO.Unsafe
import Prelude
withGhcModEnv :: (IOish m, GmOut m) => FilePath -> Options -> ((GhcModEnv, GhcModLog) -> m a) -> m a
withGhcModEnv dir opts f = withGhcModEnv' withCradle dir opts f
where
withCradle dir' =
gbracket
(runJournalT $ do
gmSetLogLevel $ ooptLogLevel $ optOutput opts
findCradle' (optPrograms opts) dir')
(liftIO . cleanupCradle . fst)
cwdLock :: MVar ThreadId
cwdLock = unsafePerformIO $ newEmptyMVar
{-# NOINLINE cwdLock #-}
withGhcModEnv' :: (IOish m, GmOut m) => (FilePath -> ((Cradle, GhcModLog) -> m a) -> m a) -> FilePath -> Options -> ((GhcModEnv, GhcModLog) -> m a) -> m a
withGhcModEnv' withCradle dir opts f =
withCradle dir $ \(crdl,lg) ->
withCradleRootDir crdl $
f (GhcModEnv opts crdl, lg)
where
swapCurrentDirectory ndir = do
odir <- canonicalizePath =<< getCurrentDirectory
setCurrentDirectory ndir
return odir
withCradleRootDir (cradleRootDir -> projdir) a = do
success <- liftIO $ tryPutMVar cwdLock =<< myThreadId
if not success
then error "withGhcModEnv': using ghc-mod from multiple threads is not supported!"
else gbracket setup teardown (const a)
where
setup = liftIO $ swapCurrentDirectory projdir
teardown odir = liftIO $ do
setCurrentDirectory odir
void $ takeMVar cwdLock
runGmOutT :: IOish m => Options -> GmOutT m a -> m a
runGmOutT opts ma = do
gmo@GhcModOut{..} <- GhcModOut (optOutput opts) <$> liftIO newChan
let action = runGmOutT' gmo ma
case ooptLinePrefix $ optOutput opts of
Nothing -> action
Just pfxs ->
gbracket_ (liftIO $ forkIO $ stdoutGateway pfxs gmoChan)
(const $ liftIO $ flushStdoutGateway gmoChan)
action
runGmOutT' :: GhcModOut -> GmOutT m a -> m a
runGmOutT' gmo ma = flip runReaderT gmo $ unGmOutT ma
-- | Run a @GhcModT m@ computation.
runGhcModT :: IOish m
=> Options
-> GhcModT m a
-> m (Either GhcModError a, GhcModLog)
runGhcModT opt action = liftIO (getCurrentDirectory >>= canonicalizePath) >>= \dir' -> do
runGmOutT opt $
withGhcModEnv dir' opt $ \(env,lg) ->
first (fst <$>) <$> runGhcModT' env defaultGhcModState (do
gmSetLogLevel (ooptLogLevel $ optOutput opt)
gmAppendLogQuiet lg
action)
-- | @hoistGhcModT result@. Embed a GhcModT computation's result into a GhcModT
-- computation. Note that if the computation that returned @result@ modified the
-- state part of GhcModT this cannot be restored.
hoistGhcModT :: IOish m
=> (Either GhcModError a, GhcModLog)
-> GhcModT m a
hoistGhcModT (r,l) = do
gmlJournal l >> case r of
Left e -> throwError e
Right a -> return a
-- | Run a computation inside @GhcModT@ providing the RWST environment and
-- initial state. This is a low level function, use it only if you know what to
-- do with 'GhcModEnv' and 'GhcModState'.
--
-- You should probably look at 'runGhcModT' instead.
runGhcModT' :: IOish m
=> GhcModEnv
-> GhcModState
-> GhcModT m a
-> GmOutT m (Either GhcModError (a, GhcModState), GhcModLog)
runGhcModT' r s a = do
flip runReaderT r $ runJournalT $ runErrorT $ runStateT (unGmT a) s
gbracket_ :: ExceptionMonad m => m a -> (a -> m b) -> m c -> m c
gbracket_ ma mb mc = gbracket ma mb (const mc)