X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcEnv.lhs;h=98db64c9760e61fb78ae2c9905e0a36be458a356;hp=a23795cf6d3975b0546b4df357df73ec3959a8a4;hb=9319fbaf14f420cbbd9e670093cc86c5f04b7800;hpb=3f1b316d7035c55cd712cd39a9981339bcef2e8c diff --git a/compiler/typecheck/TcEnv.lhs b/compiler/typecheck/TcEnv.lhs index a23795c..98db64c 100644 --- a/compiler/typecheck/TcEnv.lhs +++ b/compiler/typecheck/TcEnv.lhs @@ -3,13 +3,6 @@ % \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 TcEnv( TyThing(..), TcTyThing(..), TcId, @@ -35,7 +28,6 @@ module TcEnv( tcLookupId, tcLookupTyVar, getScopedTyVarBinds, lclEnvElts, getInLocalScope, findGlobals, wrongThingErr, pprBinders, - refineEnvironment, tcExtendRecEnv, -- For knot-tying @@ -61,7 +53,6 @@ import IfaceEnv import TcRnMonad import TcMType import TcType -import TcGadt -- import TcSuspension import qualified Type import Var @@ -73,7 +64,6 @@ import FamInstEnv import DataCon import TyCon import TypeRep -import Coercion import Class import Name import PrelNames @@ -83,6 +73,7 @@ import HscTypes import SrcLoc import Outputable import Maybes +import FastString \end{code} @@ -134,32 +125,44 @@ tcLookupGlobal name }}}}} tcLookupField :: Name -> TcM Id -- Returns the selector Id -tcLookupField name - = tcLookupGlobal name `thenM` \ thing -> +tcLookupField name = do + thing <- tcLookup name -- Note [Record field lookup] case thing of - AnId id -> return id - other -> wrongThingErr "field name" (AGlobal thing) name + AGlobal (AnId id) -> return id + thing -> wrongThingErr "field name" thing name + +{- Note [Record field lookup] + ~~~~~~~~~~~~~~~~~~~~~~~~~~ +You might think we should have tcLookupGlobal here, since record fields +are always top level. But consider + f = e { f = True } +Then the renamer (which does not keep track of what is a record selector +and what is not) will rename the definition thus + f_7 = e { f_7 = True } +Now the type checker will find f_7 in the *local* type environment, not +the global one. It's wrong, of course, but we want to report a tidy +error, not in TcEnv.notFound. -} tcLookupDataCon :: Name -> TcM DataCon -tcLookupDataCon name - = tcLookupGlobal name `thenM` \ thing -> +tcLookupDataCon name = do + thing <- tcLookupGlobal name case thing of ADataCon con -> return con - other -> wrongThingErr "data constructor" (AGlobal thing) name + _ -> wrongThingErr "data constructor" (AGlobal thing) name tcLookupClass :: Name -> TcM Class -tcLookupClass name - = tcLookupGlobal name `thenM` \ thing -> +tcLookupClass name = do + thing <- tcLookupGlobal name case thing of AClass cls -> return cls - other -> wrongThingErr "class" (AGlobal thing) name - + _ -> wrongThingErr "class" (AGlobal thing) name + tcLookupTyCon :: Name -> TcM TyCon -tcLookupTyCon name - = tcLookupGlobal name `thenM` \ thing -> +tcLookupTyCon name = do + thing <- tcLookupGlobal name case thing of ATyCon tc -> return tc - other -> wrongThingErr "type constructor" (AGlobal thing) name + _ -> wrongThingErr "type constructor" (AGlobal thing) name tcLookupLocatedGlobalId :: Located Name -> TcM Id tcLookupLocatedGlobalId = addLocM tcLookupId @@ -197,7 +200,7 @@ tcLookupFamInst tycon tys ; case lookupFamInstEnv instEnv tycon tys of [(fam_inst, rep_tys)] -> return $ Just (famInstTyCon fam_inst, rep_tys) - other -> return Nothing + _ -> return Nothing } \end{code} @@ -245,55 +248,53 @@ tcLookupLocated :: Located Name -> TcM TcTyThing tcLookupLocated = addLocM tcLookup tcLookup :: Name -> TcM TcTyThing -tcLookup name - = getLclEnv `thenM` \ local_env -> +tcLookup name = do + local_env <- getLclEnv case lookupNameEnv (tcl_env local_env) name of - Just thing -> returnM thing - Nothing -> tcLookupGlobal name `thenM` \ thing -> - returnM (AGlobal thing) + Just thing -> return thing + Nothing -> AGlobal <$> tcLookupGlobal name tcLookupTyVar :: Name -> TcM TcTyVar -tcLookupTyVar name - = tcLookup name `thenM` \ thing -> +tcLookupTyVar name = do + thing <- tcLookup name case thing of ATyVar _ ty -> return (tcGetTyVar "tcLookupTyVar" ty) - other -> pprPanic "tcLookupTyVar" (ppr name) + _ -> pprPanic "tcLookupTyVar" (ppr name) tcLookupId :: Name -> TcM Id -- Used when we aren't interested in the binding level, nor refinement. -- The "no refinement" part means that we return the un-refined Id regardless -- -- The Id is never a DataCon. (Why does that matter? see TcExpr.tcId) -tcLookupId name - = tcLookup name `thenM` \ thing -> +tcLookupId name = do + thing <- tcLookup name case thing of - ATcId { tct_id = id} -> returnM id - AGlobal (AnId id) -> returnM id - other -> pprPanic "tcLookupId" (ppr name) + ATcId { tct_id = id} -> return id + AGlobal (AnId id) -> return id + _ -> pprPanic "tcLookupId" (ppr name) tcLookupLocalIds :: [Name] -> TcM [TcId] -- We expect the variables to all be bound, and all at -- the same level as the lookup. Only used in one place... -tcLookupLocalIds ns - = getLclEnv `thenM` \ env -> - returnM (map (lookup (tcl_env env) (thLevel (tcl_th_ctxt env))) ns) +tcLookupLocalIds ns = do + env <- getLclEnv + return (map (lookup (tcl_env env) (thLevel (tcl_th_ctxt env))) ns) where lookup lenv lvl name = case lookupNameEnv lenv name of Just (ATcId { tct_id = id, tct_level = lvl1 }) -> ASSERT( lvl == lvl1 ) id - other -> pprPanic "tcLookupLocalIds" (ppr name) + _ -> pprPanic "tcLookupLocalIds" (ppr name) lclEnvElts :: TcLclEnv -> [TcTyThing] lclEnvElts env = nameEnvElts (tcl_env env) getInLocalScope :: TcM (Name -> Bool) -- Ids only -getInLocalScope = getLclEnv `thenM` \ env -> - let - lcl_env = tcl_env env - in - return (`elemNameEnv` lcl_env) +getInLocalScope = do + env <- getLclEnv + let lcl_env = tcl_env env + return (`elemNameEnv` lcl_env) \end{code} \begin{code} @@ -317,22 +318,22 @@ tcExtendTyVarEnv tvs thing_inside = tcExtendTyVarEnv2 [(tyVarName tv, mkTyVarTy tv) | tv <- tvs] thing_inside tcExtendTyVarEnv2 :: [(Name,TcType)] -> TcM r -> TcM r -tcExtendTyVarEnv2 binds thing_inside - = getLclEnv `thenM` \ env@(TcLclEnv {tcl_env = le, - tcl_tyvars = gtvs, - tcl_rdr = rdr_env}) -> +tcExtendTyVarEnv2 binds thing_inside = do + env@(TcLclEnv {tcl_env = le, + tcl_tyvars = gtvs, + tcl_rdr = rdr_env}) <- getLclEnv let rdr_env' = extendLocalRdrEnv rdr_env (map fst binds) new_tv_set = tcTyVarsOfTypes (map snd binds) le' = extendNameEnvList le [(name, ATyVar name ty) | (name, ty) <- binds] - in + -- It's important to add the in-scope tyvars to the global tyvar set -- as well. Consider -- f (_::r) = let g y = y::r in ... -- Here, g mustn't be generalised. This is also important during -- class and instance decls, when we mustn't generalise the class tyvars -- when typechecking the methods. - tc_extend_gtvs gtvs new_tv_set `thenM` \ gtvs' -> + gtvs' <- tc_extend_gtvs gtvs new_tv_set setLclEnv (env {tcl_env = le', tcl_tyvars = gtvs', tcl_rdr = rdr_env'}) thing_inside getScopedTyVarBinds :: TcM [(Name, TcType)] @@ -408,13 +409,13 @@ findGlobals :: TcTyVarSet -> TidyEnv -> TcM (TidyEnv, [SDoc]) -findGlobals tvs tidy_env - = getLclEnv `thenM` \ lcl_env -> +findGlobals tvs tidy_env = do + lcl_env <- getLclEnv go tidy_env [] (lclEnvElts lcl_env) where - go tidy_env acc [] = returnM (tidy_env, acc) - go tidy_env acc (thing : things) - = find_thing ignore_it tidy_env thing `thenM` \ (tidy_env1, maybe_doc) -> + go tidy_env acc [] = return (tidy_env, acc) + go tidy_env acc (thing : things) = do + (tidy_env1, maybe_doc) <- find_thing ignore_it tidy_env thing case maybe_doc of Just d -> go tidy_env1 (d:acc) things Nothing -> go tidy_env1 acc things @@ -422,70 +423,40 @@ findGlobals tvs tidy_env ignore_it ty = tvs `disjointVarSet` tyVarsOfType ty ----------------------- -find_thing ignore_it tidy_env (ATcId { tct_id = id }) - = zonkTcType (idType id) `thenM` \ id_ty -> +find_thing :: (TcType -> Bool) -> TidyEnv -> TcTyThing + -> TcM (TidyEnv, Maybe SDoc) +find_thing ignore_it tidy_env (ATcId { tct_id = id }) = do + id_ty <- zonkTcType (idType id) if ignore_it id_ty then - returnM (tidy_env, Nothing) - else let + return (tidy_env, Nothing) + else let (tidy_env', tidy_ty) = tidyOpenType tidy_env id_ty msg = sep [ppr id <+> dcolon <+> ppr tidy_ty, - nest 2 (parens (ptext SLIT("bound at") <+> + nest 2 (parens (ptext (sLit "bound at") <+> ppr (getSrcLoc id)))] - in - returnM (tidy_env', Just msg) + in + return (tidy_env', Just msg) -find_thing ignore_it tidy_env (ATyVar tv ty) - = zonkTcType ty `thenM` \ tv_ty -> +find_thing ignore_it tidy_env (ATyVar tv ty) = do + tv_ty <- zonkTcType ty if ignore_it tv_ty then - returnM (tidy_env, Nothing) - else let + return (tidy_env, Nothing) + else let -- The name tv is scoped, so we don't need to tidy it (tidy_env1, tidy_ty) = tidyOpenType tidy_env tv_ty - msg = sep [ptext SLIT("Scoped type variable") <+> quotes (ppr tv) <+> eq_stuff, nest 2 bound_at] + msg = sep [ptext (sLit "Scoped type variable") <+> quotes (ppr tv) <+> eq_stuff, nest 2 bound_at] eq_stuff | Just tv' <- Type.getTyVar_maybe tv_ty, getOccName tv == getOccName tv' = empty | otherwise = equals <+> ppr tidy_ty -- It's ok to use Type.getTyVar_maybe because ty is zonked by now - bound_at = parens $ ptext SLIT("bound at:") <+> ppr (getSrcLoc tv) - in - returnM (tidy_env1, Just msg) + bound_at = parens $ ptext (sLit "bound at:") <+> ppr (getSrcLoc tv) + in + return (tidy_env1, Just msg) find_thing _ _ thing = pprPanic "find_thing" (ppr thing) \end{code} -\begin{code} -refineEnvironment - :: Refinement - -> Bool -- whether type equations are involved - -> TcM a - -> TcM a --- I don't think I have to refine the set of global type variables in scope --- Reason: the refinement never increases that set -refineEnvironment reft otherEquations thing_inside - | isEmptyRefinement reft -- Common case - , not otherEquations - = thing_inside - | otherwise - = do { env <- getLclEnv - ; let le' = mapNameEnv refine (tcl_env env) - ; setLclEnv (env {tcl_env = le'}) thing_inside } - where - refine elt@(ATcId { tct_co = Rigid co, tct_type = ty }) - | Just (co', ty') <- refineType reft ty - = elt { tct_co = Rigid (WpCo co' <.> co), tct_type = ty' } - refine elt@(ATcId { tct_co = Wobbly}) --- Main new idea: make wobbly things invisible whenever there --- is a refinement of any sort --- | otherEquations - = elt { tct_co = WobblyInvisible} - refine (ATyVar tv ty) - | Just (_, ty') <- refineType reft ty - = ATyVar tv ty' -- Ignore the coercion that refineType returns - - refine elt = elt -- Common case -\end{code} - %************************************************************************ %* * \subsection{The global tyvars} @@ -493,8 +464,9 @@ refineEnvironment reft otherEquations thing_inside %************************************************************************ \begin{code} -tc_extend_gtvs gtvs extra_global_tvs - = readMutVar gtvs `thenM` \ global_tvs -> +tc_extend_gtvs :: IORef VarSet -> VarSet -> TcM (IORef VarSet) +tc_extend_gtvs gtvs extra_global_tvs = do + global_tvs <- readMutVar gtvs newMutVar (global_tvs `unionVarSet` extra_global_tvs) \end{code} @@ -504,12 +476,12 @@ the environment. \begin{code} tcGetGlobalTyVars :: TcM TcTyVarSet -tcGetGlobalTyVars - = getLclEnv `thenM` \ (TcLclEnv {tcl_tyvars = gtv_var}) -> - readMutVar gtv_var `thenM` \ gbl_tvs -> - zonkTcTyVarsAndFV (varSetElems gbl_tvs) `thenM` \ gbl_tvs' -> - writeMutVar gtv_var gbl_tvs' `thenM_` - returnM gbl_tvs' +tcGetGlobalTyVars = do + (TcLclEnv {tcl_tyvars = gtv_var}) <- getLclEnv + gbl_tvs <- readMutVar gtv_var + gbl_tvs' <- zonkTcTyVarsAndFV (varSetElems gbl_tvs) + writeMutVar gtv_var gbl_tvs' + return gbl_tvs' \end{code} @@ -558,18 +530,18 @@ checkWellStaged :: SDoc -- What the stage check is for -> TcM () -- Fail if badly staged, adding an error checkWellStaged pp_thing bind_lvl use_stage | use_lvl >= bind_lvl -- OK! Used later than bound - = returnM () -- E.g. \x -> [| $(f x) |] + = return () -- E.g. \x -> [| $(f x) |] | bind_lvl == topLevel -- GHC restriction on top level splices = failWithTc $ - sep [ptext SLIT("GHC stage restriction:") <+> pp_thing, - nest 2 (ptext SLIT("is used in a top-level splice, and must be imported, not defined locally"))] + sep [ptext (sLit "GHC stage restriction:") <+> pp_thing, + nest 2 (ptext (sLit "is used in a top-level splice, and must be imported, not defined locally"))] | otherwise -- Badly staged = failWithTc $ -- E.g. \x -> $(f x) - ptext SLIT("Stage error:") <+> pp_thing <+> - hsep [ptext SLIT("is bound at stage") <+> ppr bind_lvl, - ptext SLIT("but used at stage") <+> ppr use_lvl] + ptext (sLit "Stage error:") <+> pp_thing <+> + hsep [ptext (sLit "is bound at stage") <+> ppr bind_lvl, + ptext (sLit "but used at stage") <+> ppr use_lvl] where use_lvl = thLevel use_stage @@ -601,9 +573,9 @@ tcMetaTy :: Name -> TcM Type -- Given the name of a Template Haskell data type, -- return the type -- E.g. given the name "Expr" return the type "Expr" -tcMetaTy tc_name - = tcLookupTyCon tc_name `thenM` \ t -> - returnM (mkTyConApp t []) +tcMetaTy tc_name = do + t <- tcLookupTyCon tc_name + return (mkTyConApp t []) thTopLevelId :: Id -> Bool -- See Note [What is a top-level Id?] in TcSplice @@ -628,40 +600,43 @@ But local instance decls includes as well as explicit user written ones. \begin{code} -data InstInfo +data InstInfo a = InstInfo { iSpec :: Instance, -- Includes the dfun id. Its forall'd type - iBinds :: InstBindings -- variables scope over the stuff in InstBindings! + iBinds :: InstBindings a -- variables scope over the stuff in InstBindings! } -iDFunId :: InstInfo -> DFunId +iDFunId :: InstInfo a -> DFunId iDFunId info = instanceDFunId (iSpec info) -data InstBindings +data InstBindings a = VanillaInst -- The normal case - (LHsBinds Name) -- Bindings for the instance methods - [LSig Name] -- User pragmas recorded for generating + (LHsBinds a) -- Bindings for the instance methods + [LSig a] -- User pragmas recorded for generating -- specialised instances | NewTypeDerived -- Used for deriving instances of newtypes, where the -- witness dictionary is identical to the argument -- dictionary. Hence no bindings, no pragmas. -pprInstInfo info = vcat [ptext SLIT("InstInfo:") <+> ppr (idType (iDFunId info))] +pprInstInfo :: InstInfo a -> SDoc +pprInstInfo info = vcat [ptext (sLit "InstInfo:") <+> ppr (idType (iDFunId info))] +pprInstInfoDetails :: OutputableBndr a => InstInfo a -> SDoc pprInstInfoDetails info = pprInstInfo info $$ nest 2 (details (iBinds info)) where details (VanillaInst b _) = pprLHsBinds b details NewTypeDerived = text "Derived from the representation type" -simpleInstInfoClsTy :: InstInfo -> (Class, Type) +simpleInstInfoClsTy :: InstInfo a -> (Class, Type) simpleInstInfoClsTy info = case instanceHead (iSpec info) of - (_, _, cls, [ty]) -> (cls, ty) + (_, _, cls, [ty]) -> (cls, ty) + _ -> panic "simpleInstInfoClsTy" -simpleInstInfoTy :: InstInfo -> Type +simpleInstInfoTy :: InstInfo a -> Type simpleInstInfoTy info = snd (simpleInstInfoClsTy info) -simpleInstInfoTyCon :: InstInfo -> TyCon +simpleInstInfoTyCon :: InstInfo a -> TyCon -- Gets the type constructor for a simple instance declaration, -- i.e. one of the form instance (...) => C (T a b c) where ... simpleInstInfoTyCon inst = tcTyConAppTyCon (simpleInstInfoTy inst) @@ -712,13 +687,15 @@ pprBinders :: [Name] -> SDoc pprBinders [bndr] = quotes (ppr bndr) pprBinders bndrs = pprWithCommas ppr bndrs +notFound :: Name -> TcGblEnv -> TcM TyThing notFound name env - = failWithTc (vcat[ptext SLIT("GHC internal error:") <+> quotes (ppr name) <+> - ptext SLIT("is not in scope during type checking, but it passed the renamer"), - ptext SLIT("tcg_type_env of environment:") <+> ppr (tcg_type_env env)] + = failWithTc (vcat[ptext (sLit "GHC internal error:") <+> quotes (ppr name) <+> + ptext (sLit "is not in scope during type checking, but it passed the renamer"), + ptext (sLit "tcg_type_env of environment:") <+> ppr (tcg_type_env env)] ) +wrongThingErr :: String -> TcTyThing -> Name -> TcM a wrongThingErr expected thing name = failWithTc (pprTcTyThingCategory thing <+> quotes (ppr name) <+> - ptext SLIT("used as a") <+> text expected) + ptext (sLit "used as a") <+> text expected) \end{code}