2 % (c) The AQUA Project, Glasgow University, 1993-1998
4 \section[CoreMonad]{The core pipeline monad}
7 {-# LANGUAGE UndecidableInstances #-}
13 -- ** Reading from the monad
14 getHscEnv, getAnnEnv, getRuleBase, getModule,
15 getDynFlags, getOrigNameCache,
17 -- ** Writing to the monad
20 -- ** Lifting into the monad
21 liftIO, liftIOWithCount,
22 liftIO1, liftIO2, liftIO3, liftIO4,
24 -- ** Dealing with annotations
25 findAnnotations, addAnnotation,
28 putMsg, putMsgS, errorMsg, errorMsgS,
29 fatalErrorMsg, fatalErrorMsgS,
30 debugTraceMsg, debugTraceMsgS,
42 import PrelNames ( iNTERACTIVE )
44 import Module ( Module )
45 import DynFlags ( DynFlags, DynFlag )
46 import SimplMonad ( SimplCount, plusSimplCount, zeroSimplCount )
47 import Rules ( RuleBase )
51 import IOEnv hiding ( liftIO, failM, failWithM )
52 import qualified IOEnv ( liftIO )
53 import TcEnv ( tcLookupGlobal )
54 import TcRnMonad ( TcM, initTc )
57 import qualified ErrUtils as Err
66 import Prelude hiding ( read )
69 import {-# SOURCE #-} TcSplice ( lookupThName_maybe )
70 import qualified Language.Haskell.TH as TH
74 \subsection{Monad and carried data structure definitions}
77 data CoreState = CoreState {
78 cs_uniq_supply :: UniqSupply,
82 data CoreReader = CoreReader {
84 cr_rule_base :: RuleBase,
88 data CoreWriter = CoreWriter {
89 cw_simpl_count :: SimplCount
92 emptyWriter :: DynFlags -> CoreWriter
93 emptyWriter dflags = CoreWriter {
94 cw_simpl_count = zeroSimplCount dflags
97 plusWriter :: CoreWriter -> CoreWriter -> CoreWriter
98 plusWriter w1 w2 = CoreWriter {
99 cw_simpl_count = (cw_simpl_count w1) `plusSimplCount` (cw_simpl_count w2)
102 type CoreIOEnv = IOEnv CoreReader
104 -- | The monad used by Core-to-Core passes to access common state, register simplification
105 -- statistics and so on
106 newtype CoreM a = CoreM { unCoreM :: CoreState -> CoreIOEnv (a, CoreState, CoreWriter) }
108 instance Functor CoreM where
113 instance Monad CoreM where
114 return x = CoreM (\s -> nop s x)
115 mx >>= f = CoreM $ \s -> do
116 (x, s', w1) <- unCoreM mx s
117 (y, s'', w2) <- unCoreM (f x) s'
118 return (y, s'', w1 `plusWriter` w2)
120 instance Applicative CoreM where
124 -- For use if the user has imported Control.Monad.Error from MTL
125 -- Requires UndecidableInstances
126 instance MonadPlus IO => MonadPlus CoreM where
127 mzero = CoreM (const mzero)
128 m `mplus` n = CoreM (\rs -> unCoreM m rs `mplus` unCoreM n rs)
130 instance MonadUnique CoreM where
131 getUniqueSupplyM = do
132 us <- getS cs_uniq_supply
133 let (us1, us2) = splitUniqSupply us
134 modifyS (\s -> s { cs_uniq_supply = us2 })
143 -> IO (a, SimplCount)
144 runCoreM hsc_env ann_env rule_base us mod m =
145 liftM extract $ runIOEnv reader $ unCoreM m state
147 reader = CoreReader {
148 cr_hsc_env = hsc_env,
149 cr_rule_base = rule_base,
157 extract :: (a, CoreState, CoreWriter) -> (a, SimplCount)
158 extract (value, _, writer) = (value, cw_simpl_count writer)
162 \subsection{Core combinators, not exported}
166 nop :: CoreState -> a -> CoreIOEnv (a, CoreState, CoreWriter)
169 return (x, s, emptyWriter $ (hsc_dflags . cr_hsc_env) r)
171 read :: (CoreReader -> a) -> CoreM a
172 read f = CoreM (\s -> getEnv >>= (\r -> nop s (f r)))
174 getS :: (CoreState -> a) -> CoreM a
175 getS f = CoreM (\s -> nop s (f s))
177 modifyS :: (CoreState -> CoreState) -> CoreM ()
178 modifyS f = CoreM (\s -> nop (f s) ())
180 write :: CoreWriter -> CoreM ()
181 write w = CoreM (\s -> return ((), s, w))
185 \subsection{Lifting IO into the monad}
189 -- | Lift an 'IOEnv' operation into 'CoreM'
190 liftIOEnv :: CoreIOEnv a -> CoreM a
191 liftIOEnv mx = CoreM (\s -> mx >>= (\x -> nop s x))
193 instance MonadIO CoreM where
194 liftIO = liftIOEnv . IOEnv.liftIO
196 -- | Lift an 'IO' operation into 'CoreM' while consuming its 'SimplCount'
197 liftIOWithCount :: IO (SimplCount, a) -> CoreM a
198 liftIOWithCount what = liftIO what >>= (\(count, x) -> addSimplCount count >> return x)
202 \subsection{Reader, writer and state accessors}
206 getHscEnv :: CoreM HscEnv
207 getHscEnv = read cr_hsc_env
209 getAnnEnv :: CoreM AnnEnv
210 getAnnEnv = getS cs_ann_env
212 getRuleBase :: CoreM RuleBase
213 getRuleBase = read cr_rule_base
215 getModule :: CoreM Module
216 getModule = read cr_module
218 addSimplCount :: SimplCount -> CoreM ()
219 addSimplCount count = write (CoreWriter { cw_simpl_count = count })
221 -- Convenience accessors for useful fields of HscEnv
223 getDynFlags :: CoreM DynFlags
224 getDynFlags = fmap hsc_dflags getHscEnv
226 -- | The original name cache is the current mapping from 'Module' and
227 -- 'OccName' to a compiler-wide unique 'Name'
228 getOrigNameCache :: CoreM OrigNameCache
229 getOrigNameCache = do
230 nameCacheRef <- fmap hsc_NC getHscEnv
231 liftIO $ fmap nsNames $ readIORef nameCacheRef
235 \subsection{Dealing with annotations}
239 -- | Find all the annotations we currently know about for the given target. Note that no
240 -- annotations will be returned if we haven't loaded information about the particular target
241 -- you are inquiring about: by default, only those modules that have been imported by the
242 -- program being compiled will have been loaded in this way.
244 -- To load the information from additional modules, you can use the functions 'DynamicLoading.forceLoadModuleInterfaces'
245 -- and 'DynamicLoading.forceLoadNameModuleInterface', but be aware that doing this indiscriminantly
246 -- will impose a performance penalty.
248 -- If no deserialization function is supplied, only transient annotations will be returned.
249 findAnnotations :: Typeable a => ([Word8] -> a) -> CoreAnnTarget -> CoreM [a]
250 findAnnotations deserialize target = do
252 return (findAnns deserialize ann_env target)
254 addAnnotation :: Typeable a => (a -> [Word8]) -> CoreAnnTarget -> a -> CoreM ()
255 addAnnotation serialize target what = addAnnotationToEnv $ Annotation { ann_target = target, ann_value = toSerialized serialize what }
257 addAnnotationToEnv :: Annotation -> CoreM ()
258 addAnnotationToEnv annotation = modifyS (\state -> state { cs_ann_env = extendAnnEnvList (cs_ann_env state) [annotation] })
262 \subsection{Direct screen output}
266 msg :: (DynFlags -> SDoc -> IO ()) -> SDoc -> CoreM ()
268 dflags <- getDynFlags
269 liftIO $ how dflags doc
271 -- | Output a String message to the screen
272 putMsgS :: String -> CoreM ()
273 putMsgS = putMsg . text
275 -- | Output a message to the screen
276 putMsg :: SDoc -> CoreM ()
277 putMsg = msg Err.putMsg
279 -- | Output a string error to the screen
280 errorMsgS :: String -> CoreM ()
281 errorMsgS = errorMsg . text
283 -- | Output an error to the screen
284 errorMsg :: SDoc -> CoreM ()
285 errorMsg = msg Err.errorMsg
287 -- | Output a fatal string error to the screen. Note this does not by itself cause the compiler to die
288 fatalErrorMsgS :: String -> CoreM ()
289 fatalErrorMsgS = fatalErrorMsg . text
291 -- | Output a fatal error to the screen. Note this does not by itself cause the compiler to die
292 fatalErrorMsg :: SDoc -> CoreM ()
293 fatalErrorMsg = msg Err.fatalErrorMsg
295 -- | Output a string debugging message at verbosity level of @-v@ or higher
296 debugTraceMsgS :: String -> CoreM ()
297 debugTraceMsgS = debugTraceMsg . text
299 -- | Outputs a debugging message at verbosity level of @-v@ or higher
300 debugTraceMsg :: SDoc -> CoreM ()
301 debugTraceMsg = msg (flip Err.debugTraceMsg 3)
303 -- | Show some labelled 'SDoc' if a particular flag is set or at a verbosity level of @-v -ddump-most@ or higher
304 dumpIfSet_dyn :: DynFlag -> String -> SDoc -> CoreM ()
305 dumpIfSet_dyn flag str = msg (\dflags -> Err.dumpIfSet_dyn dflags flag str)
311 initTcForLookup :: HscEnv -> TcM a -> IO a
312 initTcForLookup hsc_env = liftM (expectJust "initTcInteractive" . snd) . initTc hsc_env HsSrcFile False iNTERACTIVE
316 \subsection{Finding TyThings}
320 instance MonadThings CoreM where
321 lookupThing name = do
323 liftIO $ initTcForLookup hsc_env (tcLookupGlobal name)
327 \subsection{Template Haskell interoperability}
331 -- | Attempt to convert a Template Haskell name to one that GHC can
332 -- understand. Original TH names such as those you get when you use
333 -- the @'foo@ syntax will be translated to their equivalent GHC name
334 -- exactly. Qualified or unqualifed TH names will be dynamically bound
335 -- to names in the module being compiled, if possible. Exact TH names
336 -- will be bound to the name they represent, exactly.
337 thNameToGhcName :: TH.Name -> CoreM (Maybe Name)
338 thNameToGhcName th_name = do
340 liftIO $ initTcForLookup hsc_env (lookupThName_maybe th_name)