intero-0.1.6: src/GhciMonad.hs
{-# LANGUAGE UnboxedTuples #-}
{-# LANGUAGE MagicHash #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE CPP #-}
{-# OPTIONS_GHC -fno-cse -fno-warn-orphans #-}
-- -fno-cse is needed for GLOBAL_VAR's to behave properly
-----------------------------------------------------------------------------
--
-- Monadery code used in InteractiveUI
--
-- (c) The GHC Team 2005-2006
--
-----------------------------------------------------------------------------
module GhciMonad (
GHCi(..), startGHCi,
GHCiState(..), setGHCiState, getGHCiState, modifyGHCiState,
GHCiOption(..), isOptionSet, setOption, unsetOption,
Command,
BreakLocation(..),
TickArray,
getDynFlags,
runStmt, runDecls, resume, timeIt, recordBreak, revertCAFs,
printForUserNeverQualify, printForUserModInfo,
printForUser, printForUserPartWay, prettyLocations,
initInterpBuffering, turnOffBuffering, flushInterpBuffers,
) where
#include "HsVersions.h"
-- ghci-ng
import GhciTypes
import Data.Map.Strict (Map)
import qualified GHC
import GhcMonad hiding (liftIO)
import Outputable hiding (printForUser, printForUserPartWay)
import qualified Outputable
import Util
import DynFlags
import HscTypes
import SrcLoc
import Module
import ObjLink
import Linker
import Exception
import Numeric
import Data.Array
import Data.Int ( Int64 )
import Data.IORef
import System.CPUTime
import System.Environment
import System.IO
#if __GLASGOW_HASKELL__ < 709
import Control.Applicative (Applicative(..))
#endif
import Control.Monad
import GHC.Exts
import System.Console.Haskeline (CompletionFunc, InputT)
import qualified System.Console.Haskeline as Haskeline
import Control.Monad.Trans.Class
import Control.Monad.IO.Class
-----------------------------------------------------------------------------
-- GHCi monad
type Command = (String, String -> InputT GHCi Bool, CompletionFunc GHCi)
data GHCiState = GHCiState
{
progname :: String,
args :: [String],
prompt :: String,
prompt2 :: String,
editor :: String,
stop :: String,
options :: [GHCiOption],
line_number :: !Int, -- input line
break_ctr :: !Int,
breaks :: ![(Int, BreakLocation)],
tickarrays :: ModuleEnv TickArray,
-- tickarrays caches the TickArray for loaded modules,
-- so that we don't rebuild it each time the user sets
-- a breakpoint.
-- available ghci commands
ghci_commands :: [Command],
-- ":" at the GHCi prompt repeats the last command, so we
-- remember is here:
last_command :: Maybe Command,
cmdqueue :: [String],
remembered_ctx :: [InteractiveImport],
-- the imports that the user has asked for, via import
-- declarations and :module commands. This list is
-- persistent over :reloads (but any imports for modules
-- that are not loaded are temporarily ignored). After a
-- :load, all the home-package imports are stripped from
-- this list.
-- See bugs #2049, #1873, #1360
transient_ctx :: [InteractiveImport],
-- An import added automatically after a :load, usually of
-- the most recently compiled module. May be empty if
-- there are no modules loaded. This list is replaced by
-- :load, :reload, and :add. In between it may be modified
-- by :module.
ghc_e :: Bool, -- True if this is 'ghc -e' (or runghc)
-- help text to display to a user
short_help :: String,
long_help :: String,
-- stored state
mod_infos :: !(Map ModuleName ModInfo),
rdrNamesInScope :: ![GHC.RdrName]
}
type TickArray = Array Int [(BreakIndex,SrcSpan)]
data GHCiOption
= ShowTiming -- show time/allocs after evaluation
| ShowType -- show the type of expressions
| RevertCAFs -- revert CAFs after every evaluation
| Multiline -- use multiline commands
deriving Eq
data BreakLocation
= BreakLocation
{ breakModule :: !GHC.Module
, breakLoc :: !SrcSpan
, breakTick :: {-# UNPACK #-} !Int
, onBreakCmd :: String
}
instance Eq BreakLocation where
loc1 == loc2 = breakModule loc1 == breakModule loc2 &&
breakTick loc1 == breakTick loc2
prettyLocations :: [(Int, BreakLocation)] -> SDoc
prettyLocations [] = text "No active breakpoints."
prettyLocations locs = vcat $ map (\(i, loc) -> brackets (int i) <+> ppr loc) $ reverse $ locs
instance Outputable BreakLocation where
ppr loc = (ppr $ breakModule loc) <+> ppr (breakLoc loc) <+>
if null (onBreakCmd loc)
then empty
else doubleQuotes (text (onBreakCmd loc))
recordBreak :: BreakLocation -> GHCi (Bool{- was already present -}, Int)
recordBreak brkLoc = do
st <- getGHCiState
let oldActiveBreaks = breaks st
-- don't store the same break point twice
case [ nm | (nm, loc) <- oldActiveBreaks, loc == brkLoc ] of
(nm:_) -> return (True, nm)
[] -> do
let oldCounter = break_ctr st
newCounter = oldCounter + 1
setGHCiState $ st { break_ctr = newCounter,
breaks = (oldCounter, brkLoc) : oldActiveBreaks
}
return (False, oldCounter)
newtype GHCi a = GHCi { unGHCi :: IORef GHCiState -> Ghc a }
reflectGHCi :: (Session, IORef GHCiState) -> GHCi a -> IO a
reflectGHCi (s, gs) m = unGhc (unGHCi m gs) s
reifyGHCi :: ((Session, IORef GHCiState) -> IO a) -> GHCi a
reifyGHCi f = GHCi f'
where
-- f' :: IORef GHCiState -> Ghc a
f' gs = reifyGhc (f'' gs)
-- f'' :: IORef GHCiState -> Session -> IO a
f'' gs s = f (s, gs)
startGHCi :: GHCi a -> GHCiState -> Ghc a
startGHCi g state = do ref <- liftIO $ newIORef state; unGHCi g ref
instance Functor GHCi where
fmap = liftM
instance Applicative GHCi where
pure = return
(<*>) = ap
instance Monad GHCi where
(GHCi m) >>= k = GHCi $ \s -> m s >>= \a -> unGHCi (k a) s
return a = GHCi $ \_ -> return a
getGHCiState :: GHCi GHCiState
getGHCiState = GHCi $ \r -> liftIO $ readIORef r
setGHCiState :: GHCiState -> GHCi ()
setGHCiState s = GHCi $ \r -> liftIO $ writeIORef r s
modifyGHCiState :: (GHCiState -> GHCiState) -> GHCi ()
modifyGHCiState f = GHCi $ \r -> liftIO $ readIORef r >>= writeIORef r . f
liftGhc :: Ghc a -> GHCi a
liftGhc m = GHCi $ \_ -> m
instance MonadIO GHCi where
liftIO = liftGhc . liftIO
instance HasDynFlags GHCi where
getDynFlags = getSessionDynFlags
instance GhcMonad GHCi where
setSession s' = liftGhc $ setSession s'
getSession = liftGhc $ getSession
instance HasDynFlags (InputT GHCi) where
getDynFlags = lift getDynFlags
instance GhcMonad (InputT GHCi) where
setSession = lift . setSession
getSession = lift getSession
instance ExceptionMonad GHCi where
gcatch m h = GHCi $ \r -> unGHCi m r `gcatch` (\e -> unGHCi (h e) r)
gmask f =
GHCi $ \s -> gmask $ \io_restore ->
let
g_restore (GHCi m) = GHCi $ \s' -> io_restore (m s')
in
unGHCi (f g_restore) s
instance Haskeline.MonadException Ghc where
controlIO f = Ghc $ \s -> Haskeline.controlIO $ \(Haskeline.RunIO run) -> let
run' = Haskeline.RunIO (fmap (Ghc . const) . run . flip unGhc s)
in fmap (flip unGhc s) $ f run'
instance Haskeline.MonadException GHCi where
controlIO f = GHCi $ \s -> Haskeline.controlIO $ \(Haskeline.RunIO run) -> let
run' = Haskeline.RunIO (fmap (GHCi . const) . run . flip unGHCi s)
in fmap (flip unGHCi s) $ f run'
instance ExceptionMonad (InputT GHCi) where
gcatch = Haskeline.catch
gmask f = Haskeline.liftIOOp gmask (f . Haskeline.liftIOOp_)
isOptionSet :: GHCiOption -> GHCi Bool
isOptionSet opt
= do st <- getGHCiState
return (opt `elem` options st)
setOption :: GHCiOption -> GHCi ()
setOption opt
= do st <- getGHCiState
setGHCiState (st{ options = opt : filter (/= opt) (options st) })
unsetOption :: GHCiOption -> GHCi ()
unsetOption opt
= do st <- getGHCiState
setGHCiState (st{ options = filter (/= opt) (options st) })
printForUserNeverQualify :: GhcMonad m => SDoc -> m ()
printForUserNeverQualify doc = do
dflags <- getDynFlags
liftIO $ Outputable.printForUser dflags stdout neverQualify doc
printForUserModInfo :: GhcMonad m => GHC.ModuleInfo -> SDoc -> m ()
printForUserModInfo info doc = do
dflags <- getDynFlags
mUnqual <- GHC.mkPrintUnqualifiedForModule info
unqual <- maybe GHC.getPrintUnqual return mUnqual
liftIO $ Outputable.printForUser dflags stdout unqual doc
printForUser :: GhcMonad m => SDoc -> m ()
printForUser doc = do
unqual <- GHC.getPrintUnqual
dflags <- getDynFlags
liftIO $ Outputable.printForUser dflags stdout unqual doc
printForUserPartWay :: SDoc -> GHCi ()
printForUserPartWay doc = do
unqual <- GHC.getPrintUnqual
dflags <- getDynFlags
liftIO $ Outputable.printForUserPartWay dflags stdout (pprUserLength dflags) unqual doc
-- | Run a single Haskell expression
runStmt :: String -> GHC.SingleStep -> GHCi (Maybe GHC.RunResult)
runStmt expr step = do
st <- getGHCiState
reifyGHCi $ \x ->
withProgName (progname st) $
withArgs (args st) $
reflectGHCi x $ do
GHC.handleSourceError (\e -> do GHC.printException e;
return Nothing) $ do
r <- GHC.runStmtWithLocation (progname st) (line_number st) expr step
return (Just r)
runDecls :: String -> GHCi [GHC.Name]
runDecls decls = do
st <- getGHCiState
reifyGHCi $ \x ->
withProgName (progname st) $
withArgs (args st) $
reflectGHCi x $ do
GHC.handleSourceError (\e -> do GHC.printException e; return []) $ do
GHC.runDeclsWithLocation (progname st) (line_number st) decls
resume :: (SrcSpan -> Bool) -> GHC.SingleStep -> GHCi GHC.RunResult
resume canLogSpan step = do
st <- getGHCiState
reifyGHCi $ \x ->
withProgName (progname st) $
withArgs (args st) $
reflectGHCi x $ do
GHC.resume canLogSpan step
-- --------------------------------------------------------------------------
-- timing & statistics
timeIt :: InputT GHCi a -> InputT GHCi a
timeIt action
= do b <- lift $ isOptionSet ShowTiming
if not b
then action
else do allocs1 <- liftIO $ getAllocations
time1 <- liftIO $ getCPUTime
a <- action
allocs2 <- liftIO $ getAllocations
time2 <- liftIO $ getCPUTime
dflags <- getDynFlags
liftIO $ printTimes dflags (fromIntegral (allocs2 - allocs1))
(time2 - time1)
return a
foreign import ccall unsafe "getAllocations" getAllocations :: IO Int64
-- defined in ghc/rts/Stats.c
printTimes :: DynFlags -> Integer -> Integer -> IO ()
printTimes dflags allocs psecs
= do let secs = (fromIntegral psecs / (10^(12::Integer))) :: Float
secs_str = showFFloat (Just 2) secs
putStrLn (showSDoc dflags (
parens (text (secs_str "") <+> text "secs" <> comma <+>
text (show allocs) <+> text "bytes")))
-----------------------------------------------------------------------------
-- reverting CAFs
revertCAFs :: GHCi ()
revertCAFs = do
liftIO rts_revertCAFs
s <- getGHCiState
when (not (ghc_e s)) $ liftIO turnOffBuffering
-- Have to turn off buffering again, because we just
-- reverted stdout, stderr & stdin to their defaults.
foreign import ccall "revertCAFs" rts_revertCAFs :: IO ()
-- Make it "safe", just in case
-----------------------------------------------------------------------------
-- To flush buffers for the *interpreted* computation we need
-- to refer to *its* stdout/stderr handles
GLOBAL_VAR(stdin_ptr, error "no stdin_ptr", Ptr ())
GLOBAL_VAR(stdout_ptr, error "no stdout_ptr", Ptr ())
GLOBAL_VAR(stderr_ptr, error "no stderr_ptr", Ptr ())
-- After various attempts, I believe this is the least bad way to do
-- what we want. We know look up the address of the static stdin,
-- stdout, and stderr closures in the loaded base package, and each
-- time we need to refer to them we cast the pointer to a Handle.
-- This avoids any problems with the CAF having been reverted, because
-- we'll always get the current value.
--
-- The previous attempt that didn't work was to compile an expression
-- like "hSetBuffering stdout NoBuffering" into an expression of type
-- IO () and run this expression each time we needed it, but the
-- problem is that evaluating the expression might cache the contents
-- of the Handle rather than referring to it from its static address
-- each time. There's no safe workaround for this.
initInterpBuffering :: Ghc ()
initInterpBuffering = do -- make sure these are linked
dflags <- GHC.getSessionDynFlags
liftIO $ do
initDynLinker dflags
-- ToDo: we should really look up these names properly, but
-- it's a fiddle and not all the bits are exposed via the GHC
-- interface.
mb_stdin_ptr <- ObjLink.lookupSymbol "base_GHCziIOziHandleziFD_stdin_closure"
mb_stdout_ptr <- ObjLink.lookupSymbol "base_GHCziIOziHandleziFD_stdout_closure"
mb_stderr_ptr <- ObjLink.lookupSymbol "base_GHCziIOziHandleziFD_stderr_closure"
let f ref (Just ptr) = writeIORef ref ptr
f _ Nothing = panic "interactiveUI:setBuffering2"
zipWithM_ f [stdin_ptr,stdout_ptr,stderr_ptr]
[mb_stdin_ptr,mb_stdout_ptr,mb_stderr_ptr]
flushInterpBuffers :: GHCi ()
flushInterpBuffers
= liftIO $ do getHandle stdout_ptr >>= hFlush
getHandle stderr_ptr >>= hFlush
turnOffBuffering :: IO ()
turnOffBuffering
= do hdls <- mapM getHandle [stdin_ptr,stdout_ptr,stderr_ptr]
mapM_ (\h -> hSetBuffering h NoBuffering) hdls
getHandle :: IORef (Ptr ()) -> IO Handle
getHandle ref = do
(Ptr addr) <- readIORef ref
case addrToAny# addr of (# hval #) -> return (unsafeCoerce# hval)