X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FTcEnv.lhs;h=cf86e56718eebfe79ffc5b1ca3fa0d34bc8d9198;hb=f714e6b642fd614a9971717045ae47c3d871275e;hp=06f17d31a3c7f5c0721b23982ddb2192c746aaa4;hpb=c4f3290f3d4c2a5c2e81a97717f7fd06ee180f6d;p=ghc-hetmet.git diff --git a/ghc/compiler/typecheck/TcEnv.lhs b/ghc/compiler/typecheck/TcEnv.lhs index 06f17d3..cf86e56 100644 --- a/ghc/compiler/typecheck/TcEnv.lhs +++ b/ghc/compiler/typecheck/TcEnv.lhs @@ -1,280 +1,402 @@ \begin{code} module TcEnv( - TcIdOcc(..), TcIdBndr, tcIdType, tcIdTyVars, tcInstId, + TyThing(..), TcTyThing(..), TcId, + + -- Instance environment, and InstInfo type + InstInfo(..), pprInstInfo, pprInstInfoDetails, + simpleInstInfoTy, simpleInstInfoTyCon, + InstBindings(..), + + -- Global environment + tcExtendGlobalEnv, + tcExtendGlobalValEnv, + tcLookupLocatedGlobal, tcLookupGlobal, + tcLookupGlobalId, tcLookupTyCon, tcLookupClass, tcLookupDataCon, + tcLookupLocatedGlobalId, tcLookupLocatedTyCon, + tcLookupLocatedClass, tcLookupLocatedDataCon, + + getInGlobalScope, - TcEnv, GlobalValueEnv, + -- Local environment + tcExtendKindEnv, + tcExtendTyVarEnv, tcExtendTyVarEnv2, + tcExtendLocalValEnv, tcExtendLocalValEnv2, + tcLookup, tcLookupLocated, tcLookupLocalIds, + tcLookupId, tcLookupTyVar, + lclEnvElts, getInLocalScope, findGlobals, + wrongThingErr, - initEnv, getEnv_LocalIds, getEnv_TyCons, getEnv_Classes, - - tcExtendTyVarEnv, tcLookupTyVar, + tcExtendRecEnv, -- For knot-tying + + -- Rules + tcExtendRules, + + -- Global type variables + tcGetGlobalTyVars, - tcExtendTyConEnv, tcLookupTyCon, tcLookupTyConByKey, - tcExtendClassEnv, tcLookupClass, tcLookupClassByKey, - tcGetTyConsAndClasses, + -- Template Haskell stuff + checkWellStaged, spliceOK, bracketOK, tcMetaTy, thLevel, + topIdLvl, - tcExtendGlobalValEnv, tcExtendLocalValEnv, tcGetGlobalValEnv, tcSetGlobalValEnv, - tcLookupLocalValue, tcLookupLocalValueOK, tcLookupLocalValueByKey, - tcLookupGlobalValue, tcLookupGlobalValueByKey, tcLookupGlobalValueMaybe, - tcAddImportedIdInfo, tcExplicitLookupGlobal, - tcLookupGlobalValueByKeyMaybe, + -- Arrow stuff + checkProcLevel, - newMonoIds, newLocalIds, newLocalId, newSpecPragmaId, - tcGetGlobalTyVars, tcExtendGlobalTyVars + -- New Ids + newLocalName, newDFunName ) where #include "HsVersions.h" -import MkId ( mkUserLocal, mkUserId, mkSpecPragmaId ) -import Id ( Id, GenId, idType, replaceIdInfo, idInfo ) -import TcKind ( TcKind, kindToTcKind, Kind ) -import TcType ( TcType, TcMaybe, TcTyVar, TcTyVarSet, TcThetaType, - newTyVarTys, tcInstTyVars, zonkTcTyVars, tcInstType - ) -import TyVar ( mkTyVarSet, unionTyVarSets, emptyTyVarSet, TyVar ) -import Type ( tyVarsOfType, tyVarsOfTypes, splitForAllTys, splitRhoTy ) -import TyCon ( TyCon, tyConKind, tyConArity, isSynTyCon, Arity ) -import Class ( Class ) - -import TcMonad - -import IdInfo ( noIdInfo ) -import Name ( Name, OccName(..), nameOccName, - maybeWiredInTyConName, maybeWiredInIdName, isLocallyDefined, - NamedThing(..) +import HsSyn ( LRuleDecl, LHsBinds, LSig ) +import TcIface ( tcImportDecl ) +import TcRnMonad +import TcMType ( zonkTcType, zonkTcTyVar, zonkTcTyVarsAndFV ) +import TcType ( Type, TcKind, TcTyVar, TcTyVarSet, + tyVarsOfType, tyVarsOfTypes, tcSplitDFunTy, mkGenTyConApp, + getDFunTyKey, tcTyConAppTyCon, tyVarBindingInfo, + tidyOpenType, tidyOpenTyVar ) -import Unique ( pprUnique10{-, pprUnique ToDo:rm-}, Unique, Uniquable(..) ) -import UniqFM -import Util ( zipEqual, zipWithEqual, zipWith3Equal ) -import Maybes ( maybeToBool ) +import qualified Type ( getTyVar_maybe ) +import Id ( idName, isLocalId ) +import Var ( TyVar, Id, idType ) +import VarSet +import VarEnv +import RdrName ( extendLocalRdrEnv ) +import DataCon ( DataCon ) +import TyCon ( TyCon ) +import Class ( Class ) +import Name ( Name, NamedThing(..), getSrcLoc, mkInternalName, nameIsLocalOrFrom ) +import NameEnv +import OccName ( mkDFunOcc, occNameString ) +import HscTypes ( DFunId, extendTypeEnvList, lookupType, + TyThing(..), tyThingId, tyThingDataCon, + ExternalPackageState(..) ) + +import SrcLoc ( SrcLoc, Located(..) ) import Outputable +import Maybe ( isJust ) \end{code} + %************************************************************************ %* * -\subsection{TcId, TcIdOcc} +%* tcLookupGlobal * %* * %************************************************************************ +Using the Located versions (eg. tcLookupLocatedGlobal) is preferred, +unless you know that the SrcSpan in the monad is already set to the +span of the Name. \begin{code} -type TcIdBndr s = GenId (TcType s) -- Binders are all TcTypes -data TcIdOcc s = TcId (TcIdBndr s) -- Bindees may be either - | RealId Id +tcLookupLocatedGlobal :: Located Name -> TcM TyThing +-- c.f. IfaceEnvEnv.tcIfaceGlobal +tcLookupLocatedGlobal name + = addLocM tcLookupGlobal name + +tcLookupGlobal :: Name -> TcM TyThing +tcLookupGlobal name + = do { env <- getGblEnv + ; if nameIsLocalOrFrom (tcg_mod env) name + + then -- It's defined in this module + case lookupNameEnv (tcg_type_env env) name of + Just thing -> return thing + Nothing -> notFound "tcLookupGlobal" name + + else do -- It's imported + { eps <- getEps + ; hpt <- getHpt + ; case lookupType hpt (eps_PTE eps) name of + Just thing -> return thing + Nothing -> do { traceIf (text "tcLookupGlobal" <+> ppr name) + ; initIfaceTcRn (tcImportDecl name) } + }} +\end{code} -instance Eq (TcIdOcc s) where - (TcId id1) == (TcId id2) = id1 == id2 - (RealId id1) == (RealId id2) = id1 == id2 - _ == _ = False +\begin{code} +tcLookupGlobalId :: Name -> TcM Id +-- Never used for Haskell-source DataCons, hence no ADataCon case +tcLookupGlobalId name + = tcLookupGlobal name `thenM` \ thing -> + return (tyThingId thing) + +tcLookupDataCon :: Name -> TcM DataCon +tcLookupDataCon con_name + = tcLookupGlobal con_name `thenM` \ thing -> + return (tyThingDataCon thing) + +tcLookupClass :: Name -> TcM Class +tcLookupClass name + = tcLookupGlobal name `thenM` \ thing -> + case thing of + AClass cls -> return cls + other -> wrongThingErr "class" (AGlobal thing) name + +tcLookupTyCon :: Name -> TcM TyCon +tcLookupTyCon name + = tcLookupGlobal name `thenM` \ thing -> + case thing of + ATyCon tc -> return tc + other -> wrongThingErr "type constructor" (AGlobal thing) name -instance Ord (TcIdOcc s) where - (TcId id1) `compare` (TcId id2) = id1 `compare` id2 - (RealId id1) `compare` (RealId id2) = id1 `compare` id2 - (TcId _) `compare` (RealId _) = LT - (RealId _) `compare` (TcId _) = GT +tcLookupLocatedGlobalId :: Located Name -> TcM Id +tcLookupLocatedGlobalId = addLocM tcLookupId -instance Outputable (TcIdOcc s) where - ppr (TcId id) = ppr id - ppr (RealId id) = ppr id +tcLookupLocatedDataCon :: Located Name -> TcM DataCon +tcLookupLocatedDataCon = addLocM tcLookupDataCon -instance NamedThing (TcIdOcc s) where - getName (TcId id) = getName id - getName (RealId id) = getName id +tcLookupLocatedClass :: Located Name -> TcM Class +tcLookupLocatedClass = addLocM tcLookupClass +tcLookupLocatedTyCon :: Located Name -> TcM TyCon +tcLookupLocatedTyCon = addLocM tcLookupTyCon +\end{code} -tcIdType :: TcIdOcc s -> TcType s -tcIdType (TcId id) = idType id -tcIdType (RealId id) = pprPanic "tcIdType:" (ppr id) +%************************************************************************ +%* * + Extending the global environment +%* * +%************************************************************************ -tcIdTyVars (TcId id) = tyVarsOfType (idType id) -tcIdTyVars (RealId _) = emptyTyVarSet -- Top level Ids have no free type variables +\begin{code} +tcExtendGlobalEnv :: [TyThing] -> TcM r -> TcM r + -- Given a mixture of Ids, TyCons, Classes, all from the + -- module being compiled, extend the global environment +tcExtendGlobalEnv things thing_inside + = do { env <- getGblEnv + ; let ge' = extendTypeEnvList (tcg_type_env env) things + ; setGblEnv (env {tcg_type_env = ge'}) thing_inside } + +tcExtendGlobalValEnv :: [Id] -> TcM a -> TcM a + -- Same deal as tcExtendGlobalEnv, but for Ids +tcExtendGlobalValEnv ids thing_inside + = tcExtendGlobalEnv [AnId id | id <- ids] thing_inside +\end{code} --- A useful function that takes an occurrence of a global thing --- and instantiates its type with fresh type variables -tcInstId :: Id - -> NF_TcM s ([TcTyVar s], -- It's instantiated type - TcThetaType s, -- - TcType s) -- +A variety of global lookups, when we know what we are looking for. -tcInstId id - = let - (tyvars, rho) = splitForAllTys (idType id) - in - tcInstTyVars tyvars `thenNF_Tc` \ (tyvars', arg_tys, tenv) -> - tcInstType tenv rho `thenNF_Tc` \ rho' -> - let - (theta', tau') = splitRhoTy rho' - in - returnNF_Tc (tyvars', theta', tau') +\begin{code} +getInGlobalScope :: TcM (Name -> Bool) +-- Get all things in the global environment; used for deciding what +-- rules to suck in. Anything defined in this module (nameIsLocalOrFrom) +-- is certainly in the envt, so we don't bother to look. +getInGlobalScope + = do { mod <- getModule + ; eps <- getEps + ; hpt <- getHpt + ; return (\n -> nameIsLocalOrFrom mod n || + isJust (lookupType hpt (eps_PTE eps) n)) } +\end{code} + + +\begin{code} +tcExtendRecEnv :: [(Name,TyThing)] -> TcM r -> TcM r +-- Extend the global environments for the type/class knot tying game +tcExtendRecEnv gbl_stuff thing_inside + = updGblEnv upd thing_inside + where + upd env = env { tcg_type_env = extend (tcg_type_env env) } + extend env = extendNameEnvList env gbl_stuff \end{code} %************************************************************************ %* * -\subsection{TcEnv} +\subsection{The local environment} %* * %************************************************************************ -Data type declarations -~~~~~~~~~~~~~~~~~~~~~ - \begin{code} -data TcEnv s = TcEnv - (TyVarEnv s) - (TyConEnv s) - (ClassEnv s) - GlobalValueEnv - (ValueEnv (TcIdBndr s)) -- Locals - (TcRef s (TcTyVarSet s)) -- Free type variables of locals - -- ...why mutable? see notes with tcGetGlobalTyVars - -type TyVarEnv s = UniqFM (TcKind s, TyVar) -type TyConEnv s = UniqFM (TcKind s, Maybe Arity, TyCon) -- Arity present for Synonyms only -type ClassEnv s = UniqFM ([TcKind s], Class) -- The kinds are the kinds of the args - -- to the class -type ValueEnv id = UniqFM id -type GlobalValueEnv = ValueEnv Id -- Globals - -initEnv :: TcRef s (TcTyVarSet s) -> TcEnv s -initEnv mut = TcEnv emptyUFM emptyUFM emptyUFM emptyUFM emptyUFM mut - -getEnv_LocalIds (TcEnv _ _ _ _ ls _) = eltsUFM ls -getEnv_TyCons (TcEnv _ ts _ _ _ _) = [tycon | (_, _, tycon) <- eltsUFM ts] -getEnv_Classes (TcEnv _ _ cs _ _ _) = [clas | (_, clas) <- eltsUFM cs] +tcLookupLocated :: Located Name -> TcM TcTyThing +tcLookupLocated = addLocM tcLookup + +tcLookup :: Name -> TcM TcTyThing +tcLookup name + = getLclEnv `thenM` \ local_env -> + case lookupNameEnv (tcl_env local_env) name of + Just thing -> returnM thing + Nothing -> tcLookupGlobal name `thenM` \ thing -> + returnM (AGlobal thing) + +tcLookupTyVar :: Name -> TcM Id +tcLookupTyVar name + = tcLookup name `thenM` \ thing -> + case thing of + ATyVar tv -> returnM tv + other -> pprPanic "tcLookupTyVar" (ppr name) + +tcLookupId :: Name -> TcM Id +-- Used when we aren't interested in the binding level +-- Never a DataCon. (Why does that matter? see TcExpr.tcId) +tcLookupId name + = tcLookup name `thenM` \ thing -> + case thing of + ATcId tc_id _ _ -> returnM tc_id + AGlobal (AnId id) -> returnM id + other -> 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) + where + lookup lenv lvl name + = case lookupNameEnv lenv name of + Just (ATcId id lvl1 _) -> ASSERT( lvl == lvl1 ) id + other -> 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) \end{code} -Type variable env -~~~~~~~~~~~~~~~~~ \begin{code} -tcExtendTyVarEnv :: [Name] -> [(TcKind s, TyVar)] -> TcM s r -> TcM s r -tcExtendTyVarEnv names kinds_w_types scope - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> +tcExtendKindEnv :: [(Name, TcKind)] -> TcM r -> TcM r +tcExtendKindEnv things thing_inside + = updLclEnv upd thing_inside + where + upd lcl_env = lcl_env { tcl_env = extend (tcl_env lcl_env) } + extend env = extendNameEnvList env [(n, AThing k) | (n,k) <- things] + +tcExtendTyVarEnv :: [TyVar] -> TcM r -> TcM r +tcExtendTyVarEnv tvs thing_inside + = tc_extend_tv_env [(getName tv, ATyVar tv) | tv <- tvs] tvs thing_inside + +tcExtendTyVarEnv2 :: [(TyVar,TcTyVar)] -> TcM r -> TcM r +tcExtendTyVarEnv2 tv_pairs thing_inside + = tc_extend_tv_env [(getName tv1, ATyVar tv2) | (tv1,tv2) <- tv_pairs] + [tv | (_,tv) <- tv_pairs] + thing_inside + +tc_extend_tv_env binds tyvars thing_inside + = getLclEnv `thenM` \ env@(TcLclEnv {tcl_env = le, + tcl_tyvars = gtvs, + tcl_rdr = rdr_env}) -> let - tve' = addListToUFM tve (zipEqual "tcTyVarScope" names kinds_w_types) + le' = extendNameEnvList le binds + rdr_env' = extendLocalRdrEnv rdr_env (map fst binds) + new_tv_set = mkVarSet tyvars in - tcSetEnv (TcEnv tve' tce ce gve lve gtvs) scope + -- 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' -> + setLclEnv (env {tcl_env = le', tcl_tyvars = gtvs', tcl_rdr = rdr_env'}) thing_inside \end{code} -The Kind, TyVar, Class and TyCon envs -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ - -Extending the environments. \begin{code} -tcExtendTyConEnv :: [(Name, (TcKind s, Maybe Arity, TyCon))] -> TcM s r -> TcM s r - -tcExtendTyConEnv bindings scope - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> +tcExtendLocalValEnv :: [TcId] -> TcM a -> TcM a +tcExtendLocalValEnv ids thing_inside + = getLclEnv `thenM` \ env -> let - tce' = addListToUFM tce bindings + extra_global_tyvars = tyVarsOfTypes [idType id | id <- ids] + th_lvl = thLevel (tcl_th_ctxt env) + proc_lvl = proc_level (tcl_arrow_ctxt env) + extra_env = [(idName id, ATcId id th_lvl proc_lvl) | id <- ids] + le' = extendNameEnvList (tcl_env env) extra_env + rdr_env' = extendLocalRdrEnv (tcl_rdr env) (map idName ids) in - tcSetEnv (TcEnv tve tce' ce gve lve gtvs) scope + tc_extend_gtvs (tcl_tyvars env) extra_global_tyvars `thenM` \ gtvs' -> + setLclEnv (env {tcl_env = le', tcl_tyvars = gtvs', tcl_rdr = rdr_env'}) thing_inside - -tcExtendClassEnv :: [(Name, ([TcKind s], Class))] -> TcM s r -> TcM s r -tcExtendClassEnv bindings scope - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> +tcExtendLocalValEnv2 :: [(Name,TcId)] -> TcM a -> TcM a +tcExtendLocalValEnv2 names_w_ids thing_inside + = getLclEnv `thenM` \ env -> let - ce' = addListToUFM ce bindings + extra_global_tyvars = tyVarsOfTypes [idType id | (name,id) <- names_w_ids] + th_lvl = thLevel (tcl_th_ctxt env) + proc_lvl = proc_level (tcl_arrow_ctxt env) + extra_env = [(name, ATcId id th_lvl proc_lvl) | (name,id) <- names_w_ids] + le' = extendNameEnvList (tcl_env env) extra_env + rdr_env' = extendLocalRdrEnv (tcl_rdr env) (map fst names_w_ids) in - tcSetEnv (TcEnv tve tce ce' gve lve gtvs) scope + tc_extend_gtvs (tcl_tyvars env) extra_global_tyvars `thenM` \ gtvs' -> + setLclEnv (env {tcl_env = le', tcl_tyvars = gtvs', tcl_rdr = rdr_env'}) thing_inside \end{code} -Looking up in the environments. - \begin{code} -tcLookupTyVar name - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - returnNF_Tc (lookupWithDefaultUFM tve (pprPanic "tcLookupTyVar:" (ppr name)) name) - - -tcLookupTyCon name - = -- Try for a wired-in tycon - case maybeWiredInTyConName name of { - Just tc | isSynTyCon tc -> returnTc (kind, Just (tyConArity tc), tc) - | otherwise -> returnTc (kind, Nothing, tc) - where { - kind = kindToTcKind (tyConKind tc) - }; - - Nothing -> - - -- Try in the environment - tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - case lookupUFM tce name of { - Just stuff -> returnTc stuff; - - Nothing -> - - -- Could be that he's using a class name as a type constructor - case lookupUFM ce name of - Just _ -> failWithTc (classAsTyConErr name) - Nothing -> pprPanic "tcLookupTyCon:" (ppr name) - } } - -tcLookupTyConByKey uniq - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - let - (kind, arity, tycon) = lookupWithDefaultUFM_Directly tce - (pprPanic "tcLookupTyConByKey:" (pprUnique10 uniq)) - uniq +----------------------- +-- findGlobals looks at the value environment and finds values +-- whose types mention the offending type variable. It has to be +-- careful to zonk the Id's type first, so it has to be in the monad. +-- We must be careful to pass it a zonked type variable, too. + +findGlobals :: TcTyVarSet + -> TidyEnv + -> TcM (TidyEnv, [SDoc]) + +findGlobals tvs tidy_env + = getLclEnv `thenM` \ lcl_env -> + 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) -> + case maybe_doc of + Just d -> go tidy_env1 (d:acc) things + Nothing -> go tidy_env1 acc things + + ignore_it ty = not (tvs `intersectsVarSet` tyVarsOfType ty) + +----------------------- +find_thing ignore_it tidy_env (ATcId id _ _) + = zonkTcType (idType id) `thenM` \ id_ty -> + if ignore_it id_ty then + returnM (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") <+> + ppr (getSrcLoc id)))] in - returnNF_Tc tycon - -tcLookupClass name - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - case lookupUFM ce name of - Just stuff -- Common case: it's ok - -> returnTc stuff - - Nothing -- Could be that he's using a type constructor as a class - | maybeToBool (maybeWiredInTyConName name) - || maybeToBool (lookupUFM tce name) - -> failWithTc (tyConAsClassErr name) - - | otherwise -- Wierd! Renamer shouldn't let this happen - -> pprPanic "tcLookupClass" (ppr name) - -tcLookupClassByKey uniq - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - let - (kind, clas) = lookupWithDefaultUFM_Directly ce - (pprPanic "tcLookupClassByKey:" (pprUnique10 uniq)) - uniq + returnM (tidy_env', Just msg) + +find_thing ignore_it tidy_env (ATyVar tv) + = zonkTcTyVar tv `thenM` \ tv_ty -> + if ignore_it tv_ty then + returnM (tidy_env, Nothing) + else let + (tidy_env1, tv1) = tidyOpenTyVar tidy_env tv + (tidy_env2, tidy_ty) = tidyOpenType tidy_env1 tv_ty + msg = sep [ppr tv1 <+> eq_stuff, nest 2 bound_at] + + eq_stuff | Just tv' <- Type.getTyVar_maybe tv_ty, + tv == tv' = empty + | otherwise = equals <+> ppr tidy_ty + -- It's ok to use Type.getTyVar_maybe because ty is zonked by now + + bound_at = tyVarBindingInfo tv in - returnNF_Tc clas - -tcGetTyConsAndClasses :: NF_TcM s ([TyCon], [Class]) -tcGetTyConsAndClasses - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - returnNF_Tc ([tc | (_, _, tc) <- eltsUFM tce], - [c | (_, c) <- eltsUFM ce]) + returnM (tidy_env2, Just msg) \end{code} +%************************************************************************ +%* * +\subsection{The global tyvars} +%* * +%************************************************************************ -Extending and consulting the value environment -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ \begin{code} -tcExtendGlobalValEnv ids scope - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - let - gve' = addListToUFM_Directly gve [(uniqueOf id, id) | id <- ids] - in - tcSetEnv (TcEnv tve tce ce gve' lve gtvs) scope - -tcExtendLocalValEnv names ids scope - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - tcReadMutVar gtvs `thenNF_Tc` \ global_tvs -> - let - lve' = addListToUFM lve (zipEqual "tcExtendLocalValEnv" names ids) - extra_global_tyvars = tyVarsOfTypes (map idType ids) - new_global_tyvars = global_tvs `unionTyVarSets` extra_global_tyvars - in - tcNewMutVar new_global_tyvars `thenNF_Tc` \ gtvs' -> - - tcSetEnv (TcEnv tve tce ce gve lve' gtvs') scope +tc_extend_gtvs gtvs extra_global_tvs + = readMutVar gtvs `thenM` \ global_tvs -> + newMutVar (global_tvs `unionVarSet` extra_global_tvs) \end{code} @tcGetGlobalTyVars@ returns a fully-zonked set of tyvars free in the environment. @@ -282,155 +404,235 @@ To improve subsequent calls to the same function it writes the zonked set back i the environment. \begin{code} -tcGetGlobalTyVars :: NF_TcM s (TcTyVarSet s) +tcGetGlobalTyVars :: TcM TcTyVarSet tcGetGlobalTyVars - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - tcReadMutVar gtvs `thenNF_Tc` \ global_tvs -> - zonkTcTyVars global_tvs `thenNF_Tc` \ global_tvs' -> - tcWriteMutVar gtvs global_tvs' `thenNF_Tc_` - returnNF_Tc global_tvs' - -tcExtendGlobalTyVars extra_global_tvs scope - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - tcReadMutVar gtvs `thenNF_Tc` \ global_tvs -> - let - new_global_tyvars = global_tvs `unionTyVarSets` mkTyVarSet extra_global_tvs - in - tcNewMutVar new_global_tyvars `thenNF_Tc` \ gtvs' -> - tcSetEnv (TcEnv tve tce ce gve lve gtvs') scope + = 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' \end{code} + +%************************************************************************ +%* * +\subsection{Rules} +%* * +%************************************************************************ + \begin{code} -tcLookupLocalValue :: Name -> NF_TcM s (Maybe (TcIdBndr s)) -tcLookupLocalValue name - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - returnNF_Tc (lookupUFM lve name) - -tcLookupLocalValueByKey :: Unique -> NF_TcM s (Maybe (TcIdBndr s)) -tcLookupLocalValueByKey uniq - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - returnNF_Tc (lookupUFM_Directly lve uniq) - -tcLookupLocalValueOK :: String -> Name -> NF_TcM s (TcIdBndr s) -tcLookupLocalValueOK err name - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - returnNF_Tc (lookupWithDefaultUFM lve (panic err) name) - - -tcLookupGlobalValue :: Name -> NF_TcM s Id -tcLookupGlobalValue name - = case maybeWiredInIdName name of - Just id -> returnNF_Tc id - Nothing -> tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - returnNF_Tc (lookupWithDefaultUFM gve def name) - where - def = pprPanic "tcLookupGlobalValue:" (ppr name) +tcExtendRules :: [LRuleDecl Id] -> TcM a -> TcM a + -- Just pop the new rules into the EPS and envt resp + -- All the rules come from an interface file, not soruce + -- Nevertheless, some may be for this module, if we read + -- its interface instead of its source code +tcExtendRules lcl_rules thing_inside + = do { env <- getGblEnv + ; let + env' = env { tcg_rules = lcl_rules ++ tcg_rules env } + ; setGblEnv env' thing_inside } +\end{code} -tcLookupGlobalValueMaybe :: Name -> NF_TcM s (Maybe Id) -tcLookupGlobalValueMaybe name - = case maybeWiredInIdName name of - Just id -> returnNF_Tc (Just id) - Nothing -> tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - returnNF_Tc (lookupUFM gve name) +%************************************************************************ +%* * + Arrow notation proc levels +%* * +%************************************************************************ -tcLookupGlobalValueByKey :: Unique -> NF_TcM s Id -tcLookupGlobalValueByKey uniq - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - returnNF_Tc (lookupWithDefaultUFM_Directly gve def uniq) - where -#ifdef DEBUG - def = pprPanic "tcLookupGlobalValueByKey:" (pprUnique10 uniq) -#else - def = panic "tcLookupGlobalValueByKey" -#endif - -tcLookupGlobalValueByKeyMaybe :: Unique -> NF_TcM s (Maybe Id) -tcLookupGlobalValueByKeyMaybe uniq - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - returnNF_Tc (lookupUFM_Directly gve uniq) - -tcGetGlobalValEnv :: NF_TcM s GlobalValueEnv -tcGetGlobalValEnv - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - returnNF_Tc gve - -tcSetGlobalValEnv :: GlobalValueEnv -> TcM s a -> TcM s a -tcSetGlobalValEnv gve scope - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce _ lve gtvs) -> - tcSetEnv (TcEnv tve tce ce gve lve gtvs) scope - - --- Non-monadic version, environment given explicitly -tcExplicitLookupGlobal :: GlobalValueEnv -> Name -> Maybe Id -tcExplicitLookupGlobal gve name - = case maybeWiredInIdName name of - Just id -> Just id - Nothing -> lookupUFM gve name - - -- Extract the IdInfo from an IfaceSig imported from an interface file -tcAddImportedIdInfo :: GlobalValueEnv -> Id -> Id -tcAddImportedIdInfo unf_env id - | isLocallyDefined id -- Don't look up locally defined Ids, because they - -- have explicit local definitions, so we get a black hole! - = id - | otherwise - = id `replaceIdInfo` new_info - -- The Id must be returned without a data dependency on maybe_id +\begin{code} +checkProcLevel :: TcId -> ProcLevel -> TcM () +checkProcLevel id id_lvl + = do { banned <- getBannedProcLevels + ; checkTc (not (id_lvl `elem` banned)) + (procLevelErr id id_lvl) } + +procLevelErr id id_lvl + = hang (ptext SLIT("Command-bound variable") <+> quotes (ppr id) <+> ptext SLIT("is not in scope here")) + 4 (ptext SLIT("Reason: it is used in the left argument of (-<)")) +\end{code} + + +%************************************************************************ +%* * + Meta level +%* * +%************************************************************************ + +\begin{code} +instance Outputable ThStage where + ppr Comp = text "Comp" + ppr (Brack l _ _) = text "Brack" <+> int l + ppr (Splice l) = text "Splice" <+> int l + + +thLevel :: ThStage -> ThLevel +thLevel Comp = topLevel +thLevel (Splice l) = l +thLevel (Brack l _ _) = l + + +checkWellStaged :: SDoc -- What the stage check is for + -> ThLevel -- Binding level + -> ThStage -- Use stage + -> TcM () -- Fail if badly staged, adding an error +checkWellStaged pp_thing bind_lvl use_stage + | bind_lvl <= use_lvl -- OK! + = returnM () + + | 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"))] + + | otherwise -- Badly staged + = failWithTc $ + 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 - new_info = -- pprTrace "tcAdd" (ppr id) $ - case tcExplicitLookupGlobal unf_env (getName id) of - Nothing -> noIdInfo - Just imported_id -> idInfo imported_id - -- ToDo: could check that types are the same + use_lvl = thLevel use_stage + + +topIdLvl :: Id -> ThLevel +-- Globals may either be imported, or may be from an earlier "chunk" +-- (separated by declaration splices) of this module. The former +-- *can* be used inside a top-level splice, but the latter cannot. +-- Hence we give the former impLevel, but the latter topLevel +-- E.g. this is bad: +-- x = [| foo |] +-- $( f x ) +-- By the time we are prcessing the $(f x), the binding for "x" +-- will be in the global env, not the local one. +topIdLvl id | isLocalId id = topLevel + | otherwise = impLevel + +-- Indicates the legal transitions on bracket( [| |] ). +bracketOK :: ThStage -> Maybe ThLevel +bracketOK (Brack _ _ _) = Nothing -- Bracket illegal inside a bracket +bracketOK stage = (Just (thLevel stage + 1)) + +-- Indicates the legal transitions on splice($). +spliceOK :: ThStage -> Maybe ThLevel +spliceOK (Splice _) = Nothing -- Splice illegal inside splice +spliceOK stage = Just (thLevel stage - 1) + +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 (mkGenTyConApp t []) + -- Use mkGenTyConApp because it might be a synonym \end{code} +%************************************************************************ +%* * +\subsection{Making new Ids} +%* * +%************************************************************************ + Constructing new Ids -~~~~~~~~~~~~~~~~~~~~ \begin{code} --- Uses the Name as the Name of the Id -newMonoIds :: [Name] -> Kind -> ([TcIdBndr s] -> TcM s a) -> TcM s a +newLocalName :: Name -> TcM Name +newLocalName name -- Make a clone + = newUnique `thenM` \ uniq -> + returnM (mkInternalName uniq (getOccName name) (getSrcLoc name)) +\end{code} -newMonoIds names kind m - = newTyVarTys no_of_names kind `thenNF_Tc` \ tys -> - let - new_ids = zipWithEqual "newMonoIds" mk_id names tys - mk_id name ty = mkUserId name ty - in - tcExtendLocalValEnv names new_ids (m new_ids) +Make a name for the dict fun for an instance decl. It's a *local* +name for the moment. The CoreTidy pass will externalise it. Even in +--make and ghci stuff, we rebuild the instance environment each time, +so the dfun id is internal to begin with, and external when compiling +other modules + +\begin{code} +newDFunName :: Class -> [Type] -> SrcLoc -> TcM Name +newDFunName clas (ty:_) loc + = newUnique `thenM` \ uniq -> + returnM (mkInternalName uniq (mkDFunOcc dfun_string) loc) where - no_of_names = length names - -newLocalId :: OccName -> TcType s -> NF_TcM s (TcIdBndr s) -newLocalId name ty - = tcGetSrcLoc `thenNF_Tc` \ loc -> - tcGetUnique `thenNF_Tc` \ uniq -> - returnNF_Tc (mkUserLocal name uniq ty loc) - -newLocalIds :: [OccName] -> [TcType s] -> NF_TcM s [TcIdBndr s] -newLocalIds names tys - = tcGetSrcLoc `thenNF_Tc` \ loc -> - tcGetUniques (length names) `thenNF_Tc` \ uniqs -> - let - new_ids = zipWith3Equal "newLocalIds" mk_id names uniqs tys - mk_id name uniq ty = mkUserLocal name uniq ty loc - in - returnNF_Tc new_ids + -- Any string that is somewhat unique will do + dfun_string = occNameString (getOccName clas) ++ occNameString (getDFunTyKey ty) + +newDFunName clas [] loc = pprPanic "newDFunName" (ppr clas <+> ppr loc) +\end{code} + + +%************************************************************************ +%* * +\subsection{The InstInfo type} +%* * +%************************************************************************ + +The InstInfo type summarises the information in an instance declaration + + instance c => k (t tvs) where b + +It is used just for *local* instance decls (not ones from interface files). +But local instance decls includes + - derived ones + - generic ones +as well as explicit user written ones. + +\begin{code} +data InstInfo + = InstInfo { + iDFunId :: DFunId, -- The dfun id + iBinds :: InstBindings + } + +data InstBindings + = VanillaInst -- The normal case + (LHsBinds Name) -- Bindings + [LSig Name] -- User pragmas recorded for generating + -- specialised instances + + | NewTypeDerived -- Used for deriving instances of newtypes, where the + [Type] -- witness dictionary is identical to the argument + -- dictionary. Hence no bindings, no pragmas + -- The [Type] are the representation types + -- See notes in TcDeriv + +pprInstInfo info = vcat [ptext SLIT("InstInfo:") <+> ppr (idType (iDFunId info))] + +pprInstInfoDetails info = pprInstInfo info $$ nest 2 (details (iBinds info)) + where + details (VanillaInst b _) = ppr b + details (NewTypeDerived _) = text "Derived from the representation type" -newSpecPragmaId :: Name -> TcType s -> NF_TcM s (TcIdBndr s) -newSpecPragmaId name ty - = tcGetSrcLoc `thenNF_Tc` \ loc -> - tcGetUnique `thenNF_Tc` \ uniq -> - returnNF_Tc (mkSpecPragmaId (nameOccName name) uniq ty loc) +simpleInstInfoTy :: InstInfo -> Type +simpleInstInfoTy info = case tcSplitDFunTy (idType (iDFunId info)) of + (_, _, _, [ty]) -> ty + +simpleInstInfoTyCon :: InstInfo -> 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) \end{code} +%************************************************************************ +%* * +\subsection{Errors} +%* * +%************************************************************************ + \begin{code} -classAsTyConErr name - = ptext SLIT("Class used as a type constructor:") <+> ppr name +notFound wheRe name = failWithTc (text wheRe <> colon <+> quotes (ppr name) <+> + ptext SLIT("is not in scope")) -tyConAsClassErr name - = ptext SLIT("Type constructor used as a class:") <+> ppr name +wrongThingErr expected thing name + = failWithTc (pp_thing thing <+> quotes (ppr name) <+> + ptext SLIT("used as a") <+> text expected) + where + pp_thing (AGlobal (ATyCon _)) = ptext SLIT("Type constructor") + pp_thing (AGlobal (AClass _)) = ptext SLIT("Class") + pp_thing (AGlobal (AnId _)) = ptext SLIT("Identifier") + pp_thing (AGlobal (ADataCon _)) = ptext SLIT("Data constructor") + pp_thing (ATyVar _) = ptext SLIT("Type variable") + pp_thing (ATcId _ _ _) = ptext SLIT("Local identifier") \end{code}