%
+% (c) The University of Glasgow 2006
% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
-\section[DsMonad]{@DsMonad@: monadery used in desugaring}
+
+@DsMonad@: monadery used in desugaring
\begin{code}
+{-# OPTIONS -w #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and fix
+-- any warnings in the module. See
+-- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
+-- for details
+
module DsMonad (
DsM, mappM, mapAndUnzipM,
- initDs, returnDs, thenDs, listDs, fixDs, mapAndUnzipDs,
- foldlDs, foldrDs,
+ initDs, initDsTc, returnDs, thenDs, listDs, fixDs, mapAndUnzipDs,
+ foldlDs, foldrDs, ifOptDs,
newTyVarsDs, newLocalName,
duplicateLocalDs, newSysLocalDs, newSysLocalsDs, newUniqueId,
getModuleDs,
newUnique,
UniqSupply, newUniqueSupply,
- getDOptsDs,
+ getDOptsDs, getGhcModeDs, doptDs,
dsLookupGlobal, dsLookupGlobalId, dsLookupTyCon, dsLookupDataCon,
+ dsLookupClass,
DsMetaEnv, DsMetaVal(..), dsLookupMetaEnv, dsExtendMetaEnv,
-- Warnings
- DsWarning, dsWarn,
+ DsWarning, warnDs, failWithDs,
-- Data types
DsMatchContext(..),
- EquationInfo(..), MatchResult(..), DsWrapper, idWrapper,
+ EquationInfo(..), MatchResult(..), DsWrapper, idDsWrapper,
CanItFail(..), orFail
) where
#include "HsVersions.h"
import TcRnMonad
-import CoreSyn ( CoreExpr )
-import HsSyn ( HsExpr, HsMatchContext, Pat )
-import TcIface ( tcIfaceGlobal )
-import RdrName ( GlobalRdrEnv )
-import HscTypes ( TyThing(..), TypeEnv, HscEnv,
- tyThingId, tyThingTyCon, tyThingDataCon, mkPrintUnqualified )
-import Bag ( emptyBag, snocBag, Bag )
-import DataCon ( DataCon )
-import TyCon ( TyCon )
-import Id ( mkSysLocal, setIdUnique, Id )
-import Module ( Module )
-import Var ( TyVar, setTyVarUnique )
+import CoreSyn
+import HsSyn
+import TcIface
+import RdrName
+import HscTypes
+import Bag
+import DataCon
+import TyCon
+import Class
+import Id
+import Module
+import Var
import Outputable
-import SrcLoc ( noSrcSpan, SrcSpan )
-import Type ( Type )
-import UniqSupply ( UniqSupply, uniqsFromSupply )
-import Name ( Name, nameOccName )
+import SrcLoc
+import Type
+import UniqSupply
+import Name
import NameEnv
-import OccName ( occNameFS )
-import DynFlags ( DynFlags )
-import ErrUtils ( WarnMsg, mkWarnMsg )
-import Bag ( mapBag )
+import OccName
+import DynFlags
+import ErrUtils
-import DATA_IOREF ( newIORef, readIORef )
+import Data.IORef
infixr 9 `thenDs`
\end{code}
deriving ()
data EquationInfo
- = EqnInfo { eqn_wrap :: DsWrapper, -- Bindings
- eqn_pats :: [Pat Id], -- The patterns for an eqn
+ = EqnInfo { eqn_pats :: [Pat Id], -- The patterns for an eqn
eqn_rhs :: MatchResult } -- What to do after match
type DsWrapper = CoreExpr -> CoreExpr
-idWrapper e = e
+idDsWrapper e = e
-- The semantics of (match vs (EqnInfo wrap pats rhs)) is the MatchResult
-- \fail. wrap (case vs of { pats -> rhs fail })
foldlDs = foldlM
foldrDs = foldrM
mapAndUnzipDs = mapAndUnzipM
-
+ifOptDs = ifOptM
type DsWarning = (SrcSpan, SDoc)
-- Not quite the same as a WarnMsg, we have an SDoc here
data DsGblEnv = DsGblEnv {
ds_mod :: Module, -- For SCC profiling
- ds_warns :: IORef (Bag DsWarning), -- Warning messages
+ ds_unqual :: PrintUnqualified,
+ ds_msgs :: IORef Messages, -- Warning messages
ds_if_env :: (IfGblEnv, IfLclEnv) -- Used for looking up global,
-- possibly-imported things
}
| Splice (HsExpr Id) -- These bindings are introduced by
-- the PendingSplices on a HsBracketOut
--- initDs returns the UniqSupply out the end (not just the result)
-
initDs :: HscEnv
-> Module -> GlobalRdrEnv -> TypeEnv
-> DsM a
- -> IO (a, Bag WarnMsg)
+ -> IO (Maybe a)
+-- Print errors and warnings, if any arise
initDs hsc_env mod rdr_env type_env thing_inside
- = do { warn_var <- newIORef emptyBag
- ; let { if_genv = IfGblEnv { if_rec_types = Just (mod, return type_env) }
- ; if_lenv = mkIfLclEnv mod (ptext SLIT("GHC error in desugarer lookup in") <+> ppr mod)
- ; gbl_env = DsGblEnv { ds_mod = mod,
- ds_if_env = (if_genv, if_lenv),
- ds_warns = warn_var }
- ; lcl_env = DsLclEnv { ds_meta = emptyNameEnv,
- ds_loc = noSrcSpan } }
-
- ; res <- initTcRnIf 'd' hsc_env gbl_env lcl_env thing_inside
-
- ; warns <- readIORef warn_var
- ; return (res, mapBag mk_warn warns)
- }
- where
- print_unqual = mkPrintUnqualified rdr_env
-
- mk_warn :: (SrcSpan,SDoc) -> WarnMsg
- mk_warn (loc,sdoc) = mkWarnMsg loc print_unqual sdoc
+ = do { msg_var <- newIORef (emptyBag, emptyBag)
+ ; let dflags = hsc_dflags hsc_env
+ ; (ds_gbl_env, ds_lcl_env) <- mkDsEnvs dflags mod rdr_env type_env msg_var
+
+ ; either_res <- initTcRnIf 'd' hsc_env ds_gbl_env ds_lcl_env $
+ tryM thing_inside -- Catch exceptions (= errors during desugaring)
+
+ -- Display any errors and warnings
+ -- Note: if -Werror is used, we don't signal an error here.
+ ; msgs <- readIORef msg_var
+ ; printErrorsAndWarnings dflags msgs
+
+ ; let final_res | errorsFound dflags msgs = Nothing
+ | otherwise = case either_res of
+ Right res -> Just res
+ Left exn -> pprPanic "initDs" (text (show exn))
+ -- The (Left exn) case happens when the thing_inside throws
+ -- a UserError exception. Then it should have put an error
+ -- message in msg_var, so we just discard the exception
+
+ ; return final_res }
+
+initDsTc :: DsM a -> TcM a
+initDsTc thing_inside
+ = do { this_mod <- getModule
+ ; tcg_env <- getGblEnv
+ ; msg_var <- getErrsVar
+ ; dflags <- getDOpts
+ ; let type_env = tcg_type_env tcg_env
+ rdr_env = tcg_rdr_env tcg_env
+ ; ds_envs <- ioToIOEnv$ mkDsEnvs dflags this_mod rdr_env type_env msg_var
+ ; setEnvs ds_envs thing_inside }
+
+mkDsEnvs :: DynFlags -> Module -> GlobalRdrEnv -> TypeEnv -> IORef Messages -> IO (DsGblEnv, DsLclEnv)
+mkDsEnvs dflags mod rdr_env type_env msg_var
+ = do
+ sites_var <- newIORef []
+ let if_genv = IfGblEnv { if_rec_types = Just (mod, return type_env) }
+ if_lenv = mkIfLclEnv mod (ptext SLIT("GHC error in desugarer lookup in") <+> ppr mod)
+ gbl_env = DsGblEnv { ds_mod = mod,
+ ds_if_env = (if_genv, if_lenv),
+ ds_unqual = mkPrintUnqualified dflags rdr_env,
+ ds_msgs = msg_var}
+ lcl_env = DsLclEnv { ds_meta = emptyNameEnv,
+ ds_loc = noSrcSpan }
+
+ return (gbl_env, lcl_env)
+
\end{code}
%************************************************************************
getDOptsDs :: DsM DynFlags
getDOptsDs = getDOpts
+doptDs :: DynFlag -> TcRnIf gbl lcl Bool
+doptDs = doptM
+
+getGhcModeDs :: DsM GhcMode
+getGhcModeDs = getDOptsDs >>= return . ghcMode
+
getModuleDs :: DsM Module
getModuleDs = do { env <- getGblEnv; return (ds_mod env) }
putSrcSpanDs :: SrcSpan -> DsM a -> DsM a
putSrcSpanDs new_loc thing_inside = updLclEnv (\ env -> env {ds_loc = new_loc}) thing_inside
-dsWarn :: SDoc -> DsM ()
-dsWarn warn = do { env <- getGblEnv
+warnDs :: SDoc -> DsM ()
+warnDs warn = do { env <- getGblEnv
; loc <- getSrcSpanDs
- ; updMutVar (ds_warns env) (`snocBag` (loc,msg)) }
+ ; let msg = mkWarnMsg loc (ds_unqual env)
+ (ptext SLIT("Warning:") <+> warn)
+ ; updMutVar (ds_msgs env) (\ (w,e) -> (w `snocBag` msg, e)) }
where
- msg = ptext SLIT("Warning:") <+> warn
+
+failWithDs :: SDoc -> DsM a
+failWithDs err
+ = do { env <- getGblEnv
+ ; loc <- getSrcSpanDs
+ ; let msg = mkErrMsg loc (ds_unqual env) err
+ ; updMutVar (ds_msgs env) (\ (w,e) -> (w, e `snocBag` msg))
+ ; failM }
+ where
\end{code}
\begin{code}
dsLookupDataCon name
= dsLookupGlobal name `thenDs` \ thing ->
returnDs (tyThingDataCon thing)
+
+dsLookupClass :: Name -> DsM Class
+dsLookupClass name
+ = dsLookupGlobal name `thenDs` \ thing ->
+ returnDs (tyThingClass thing)
\end{code}
\begin{code}
dsExtendMetaEnv menv thing_inside
= updLclEnv (\env -> env { ds_meta = ds_meta env `plusNameEnv` menv }) thing_inside
\end{code}
-
-