\begin{code}
module TcEnv(
- TcId, TcIdSet, tcInstId,
- tcLookupDataCon,
-
- TcEnv, ValueEnv, TcTyThing(..),
-
- initEnv, getEnvTyCons, getEnvClasses,
+ 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,
- tcExtendTyVarEnv, tcExtendTyVarEnvForMeths, tcExtendTypeEnv, tcGetInScopeTyVars,
+ -- Local environment
+ tcExtendKindEnv,
+ tcExtendTyVarEnv, tcExtendTyVarEnv2,
+ tcExtendLocalValEnv, tcExtendLocalValEnv2,
+ tcLookup, tcLookupLocated, tcLookupLocalIds,
+ tcLookupId, tcLookupTyVar,
+ lclEnvElts, getInLocalScope, findGlobals,
+ wrongThingErr,
- tcLookupTy,
- tcLookupTyCon, tcLookupTyConByKey,
- tcLookupClass, tcLookupClassByKey,
+ tcExtendRecEnv, -- For knot-tying
- tcExtendGlobalValEnv, tcExtendLocalValEnv,
- tcGetValueEnv, tcSetValueEnv,
- tcAddImportedIdInfo,
+ -- Rules
+ tcExtendRules,
- tcLookupValue, tcLookupValueMaybe,
- tcLookupValueByKey, tcLookupValueByKeyMaybe,
- explicitLookupValueByKey, explicitLookupValue,
+ -- Global type variables
+ tcGetGlobalTyVars,
- newLocalId, newSpecPragmaId,
- tcGetGlobalTyVars, tcExtendGlobalTyVars,
+ -- Template Haskell stuff
+ checkWellStaged, spliceOK, bracketOK, tcMetaTy, thLevel,
+ topIdLvl,
- badCon, badPrimOp
+ -- Arrow stuff
+ checkProcLevel,
+
+ -- New Ids
+ newLocalName, newDFunName
) where
#include "HsVersions.h"
-import HsTypes ( HsTyVar, getTyVarName )
-import Id ( mkUserLocal, isDataConId_maybe )
-import MkId ( mkSpecPragmaId )
-import Var ( TyVar, Id, setVarName,
- idType, setIdInfo, idInfo, tyVarKind
- )
-import TcType ( TcType, TcTyVar, TcTyVarSet, TcThetaType,
- tcInstTyVars, zonkTcTyVars,
- TcKind, kindToTcKind
- )
-import VarEnv
-import VarSet
-import Type ( Kind, superKind,
- tyVarsOfType, tyVarsOfTypes, mkTyVarTy, substTy,
- splitForAllTys, splitRhoTy, splitFunTys, substTopTy,
- splitAlgTyConApp_maybe, getTyVar
- )
-import DataCon ( DataCon )
-import TyCon ( TyCon, tyConKind, tyConArity, isSynTyCon )
-import Class ( Class )
-
-import TcMonad
-
-import BasicTypes ( Arity )
-import IdInfo ( noIdInfo )
-import Name ( Name, OccName, nameOccName, getSrcLoc,
- maybeWiredInTyConName, maybeWiredInIdName, isLocallyDefined,
- NamedThing(..)
+import HsSyn ( LRuleDecl, LHsBinds, LSig, pprLHsBinds )
+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, Unique, Uniquable(..) )
-import FiniteMap ( lookupFM, addToFM )
-import UniqFM
-import Unique ( Uniquable(..) )
-import Util ( zipEqual, zipWith3Equal, mapAccumL )
-import Bag ( bagToList )
-import Maybes ( maybeToBool )
-import SrcLoc ( SrcLoc )
-import FastString ( FastString )
+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}
+%* 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}
+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,hpt) <- getEpsAndHpt
+ ; case lookupType hpt (eps_PTE eps) name of
+ Just thing -> return thing
+ Nothing -> do { traceIf (text "tcLookupGlobal" <+> ppr name)
+ ; initIfaceTcRn (tcImportDecl name) }
+ }}
+\end{code}
\begin{code}
-type TcId = Id -- Type may be a TcType
-type TcIdSet = IdSet
+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 s (DataCon, [TcType], TcType)
+tcLookupDataCon :: Name -> TcM DataCon
tcLookupDataCon con_name
- = tcLookupValue con_name `thenNF_Tc` \ con_id ->
- case isDataConId_maybe con_id of {
- Nothing -> failWithTc (badCon con_id);
- Just data_con ->
-
- tcInstId con_id `thenNF_Tc` \ (_, _, con_tau) ->
- -- Ignore the con_theta; overloaded constructors only
- -- behave differently when called, not when used for
- -- matching.
- let
- (arg_tys, result_ty) = splitFunTys con_tau
- in
- ASSERT( maybeToBool (splitAlgTyConApp_maybe result_ty) )
- returnTc (data_con, arg_tys, result_ty) }
-
--- 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], -- It's instantiated type
- TcThetaType, --
- TcType) --
-tcInstId id
- = let
- (tyvars, rho) = splitForAllTys (idType id)
- in
- tcInstTyVars tyvars `thenNF_Tc` \ (tyvars', arg_tys, tenv) ->
- let
- rho' = substTopTy tenv rho
- (theta', tau') = splitRhoTy rho'
- in
- returnNF_Tc (tyvars', theta', tau')
-\end{code}
+ = 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
+tcLookupLocatedGlobalId :: Located Name -> TcM Id
+tcLookupLocatedGlobalId = addLocM tcLookupId
+
+tcLookupLocatedDataCon :: Located Name -> TcM DataCon
+tcLookupLocatedDataCon = addLocM tcLookupDataCon
+
+tcLookupLocatedClass :: Located Name -> TcM Class
+tcLookupLocatedClass = addLocM tcLookupClass
+
+tcLookupLocatedTyCon :: Located Name -> TcM TyCon
+tcLookupLocatedTyCon = addLocM tcLookupTyCon
+\end{code}
%************************************************************************
%* *
-\subsection{TcEnv}
+ Extending the global environment
%* *
%************************************************************************
-Data type declarations
-~~~~~~~~~~~~~~~~~~~~~
\begin{code}
-data TcEnv = TcEnv
- TypeEnv
- ValueEnv
- (TcTyVarSet, -- The in-scope TyVars
- TcRef TcTyVarSet) -- Free type variables of the value env
- -- ...why mutable? see notes with tcGetGlobalTyVars
- -- Includes the in-scope tyvars
-
-type NameEnv val = UniqFM val -- Keyed by Names
-
-type TypeEnv = NameEnv (TcKind, Maybe Arity, TcTyThing)
-type ValueEnv = NameEnv Id
+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}
-data TcTyThing = ATyVar TcTyVar -- Mutable only so that the kind can be mutable
- -- if the kind is mutable, the tyvar must be so that
- -- zonking works
- | ATyCon TyCon
- | AClass Class
+\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}
-initEnv :: TcRef TcTyVarSet -> TcEnv
-initEnv mut = TcEnv emptyUFM emptyUFM (emptyVarSet, mut)
+%************************************************************************
+%* *
+\subsection{The local environment}
+%* *
+%************************************************************************
-getEnvTyCons (TcEnv te _ _) = [tc | (_, _, ATyCon tc) <- eltsUFM te]
-getEnvClasses (TcEnv te _ _) = [cl | (_, _, AClass cl) <- eltsUFM te]
+\begin{code}
+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}
-The TypeEnv
-~~~~~~~~~~~~
-
-Extending the type environment.
-
\begin{code}
-tcExtendTyVarEnv :: [TyVar] -> TcM s r -> TcM s r
-tcExtendTyVarEnv tyvars scope
- = tcGetEnv `thenNF_Tc` \ (TcEnv te ve (in_scope_tvs, 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
- extend_list = [ (getName tv, (kindToTcKind (tyVarKind tv), Nothing, ATyVar tv))
- | tv <- tyvars
- ]
- te' = addListToUFM te extend_list
- new_tv_set = mkVarSet tyvars
- in_scope_tvs' = in_scope_tvs `unionVarSet` new_tv_set
+ le' = extendNameEnvList le binds
+ rdr_env' = extendLocalRdrEnv rdr_env (map fst binds)
+ new_tv_set = mkVarSet tyvars
in
-- It's important to add the in-scope tyvars to the global tyvar set
-- as well. Consider
- -- f (x::r) = let g y = y::r in ...
+ -- 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 `thenNF_Tc` \ gtvs' ->
- tcSetEnv (TcEnv te' ve (in_scope_tvs', gtvs')) scope
-
--- This variant, tcExtendTyVarEnvForMeths, takes *two* bunches of tyvars:
--- the signature tyvars contain the original names
--- the instance tyvars are what those names should be mapped to
--- It's needed when typechecking the method bindings of class and instance decls
--- It does *not* extend the global tyvars; tcMethodBind does that for itself
-
-tcExtendTyVarEnvForMeths :: [TyVar] -> [TcTyVar] -> TcM s r -> TcM s r
-tcExtendTyVarEnvForMeths sig_tyvars inst_tyvars thing_inside
- = tcGetEnv `thenNF_Tc` \ (TcEnv te ve gtvs) ->
+ 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}
+
+
+\begin{code}
+tcExtendLocalValEnv :: [TcId] -> TcM a -> TcM a
+tcExtendLocalValEnv ids thing_inside
+ = getLclEnv `thenM` \ env ->
+ let
+ 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
+ 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
+
+tcExtendLocalValEnv2 :: [(Name,TcId)] -> TcM a -> TcM a
+tcExtendLocalValEnv2 names_w_ids thing_inside
+ = getLclEnv `thenM` \ env ->
let
- te' = addListToUFM te stuff
+ 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 te' ve gtvs) thing_inside
+ 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}
+
+
+\begin{code}
+-----------------------
+-- 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
- stuff = [ (getName sig_tv, (kindToTcKind (tyVarKind inst_tv), Nothing, ATyVar inst_tv))
- | (sig_tv, inst_tv) <- zipEqual "tcMeth" sig_tyvars inst_tyvars
- ]
+ 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
+ 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
+ returnM (tidy_env2, Just msg)
+\end{code}
-tcExtendGlobalTyVars extra_global_tvs scope
- = tcGetEnv `thenNF_Tc` \ (TcEnv te ve (in_scope,gtvs)) ->
- tc_extend_gtvs gtvs extra_global_tvs `thenNF_Tc` \ gtvs' ->
- tcSetEnv (TcEnv te ve (in_scope,gtvs')) scope
+%************************************************************************
+%* *
+\subsection{The global tyvars}
+%* *
+%************************************************************************
+
+\begin{code}
tc_extend_gtvs gtvs extra_global_tvs
- = tcReadMutVar gtvs `thenNF_Tc` \ global_tvs ->
- let
- new_global_tyvars = global_tvs `unionVarSet` extra_global_tvs
- in
- tcNewMutVar new_global_tyvars
+ = 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.
the environment.
\begin{code}
-tcGetGlobalTyVars :: NF_TcM s TcTyVarSet
+tcGetGlobalTyVars :: TcM TcTyVarSet
tcGetGlobalTyVars
- = tcGetEnv `thenNF_Tc` \ (TcEnv te ve (_,gtvs)) ->
- tcReadMutVar gtvs `thenNF_Tc` \ global_tvs ->
- zonkTcTyVars (varSetElems global_tvs) `thenNF_Tc` \ global_tys' ->
- let
- global_tvs' = (tyVarsOfTypes global_tys')
- in
- tcWriteMutVar gtvs global_tvs' `thenNF_Tc_`
- returnNF_Tc global_tvs'
-
-tcGetInScopeTyVars :: NF_TcM s [TcTyVar]
-tcGetInScopeTyVars
- = tcGetEnv `thenNF_Tc` \ (TcEnv te ve (in_scope_tvs, gtvs)) ->
- returnNF_Tc (varSetElems in_scope_tvs)
+ = 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}
-Type constructors and classes
+%************************************************************************
+%* *
+\subsection{Rules}
+%* *
+%************************************************************************
\begin{code}
-tcExtendTypeEnv :: [(Name, (TcKind, Maybe Arity, TcTyThing))] -> TcM s r -> TcM s r
-tcExtendTypeEnv bindings scope
- = ASSERT( null [tv | (_, (_,_,ATyVar tv)) <- bindings] )
- -- Not for tyvars; use tcExtendTyVarEnv
- tcGetEnv `thenNF_Tc` \ (TcEnv te ve gtvs) ->
- let
- te' = addListToUFM te bindings
- in
- tcSetEnv (TcEnv te' ve gtvs) scope
+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}
-Looking up in the environments.
+%************************************************************************
+%* *
+ Arrow notation proc levels
+%* *
+%************************************************************************
\begin{code}
-tcLookupTy :: Name -> NF_TcM s (TcKind, Maybe Arity, TcTyThing)
-tcLookupTy name
- = tcGetEnv `thenNF_Tc` \ (TcEnv te ve gtvs) ->
- case lookupUFM te name of {
- Just thing -> returnNF_Tc thing ;
- Nothing ->
-
- case maybeWiredInTyConName name of
- Just tc -> returnNF_Tc (kindToTcKind (tyConKind tc), maybe_arity, ATyCon tc)
- where
- maybe_arity | isSynTyCon tc = Just (tyConArity tc)
- | otherwise = Nothing
-
- Nothing -> pprPanic "tcLookupTy" (ppr name)
- }
-
-tcLookupClass :: Name -> NF_TcM s Class
-tcLookupClass name
- = tcLookupTy name `thenNF_Tc` \ (_, _, AClass clas) ->
- returnNF_Tc clas
-
-tcLookupTyCon :: Name -> NF_TcM s TyCon
-tcLookupTyCon name
- = tcLookupTy name `thenNF_Tc` \ (_, _, ATyCon tycon) ->
- returnNF_Tc tycon
-
-tcLookupClassByKey :: Unique -> NF_TcM s Class
-tcLookupClassByKey key
- = tcGetEnv `thenNF_Tc` \ (TcEnv te ve gtvs) ->
- case lookupUFM_Directly te key of
- Just (_, _, AClass cl) -> returnNF_Tc cl
- other -> pprPanic "tcLookupClassByKey:" (pprUnique10 key)
-
-tcLookupTyConByKey :: Unique -> NF_TcM s TyCon
-tcLookupTyConByKey key
- = tcGetEnv `thenNF_Tc` \ (TcEnv te ve gtvs) ->
- case lookupUFM_Directly te key of
- Just (_, _, ATyCon tc) -> returnNF_Tc tc
- other -> pprPanic "tcLookupTyConByKey:" (pprUnique10 key)
+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
+ 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{The value environment}
+\subsection{Making new Ids}
%* *
%************************************************************************
-\begin{code}
-tcExtendGlobalValEnv :: [Id] -> TcM s a -> TcM s a
-tcExtendGlobalValEnv ids scope
- = tcGetEnv `thenNF_Tc` \ (TcEnv te ve gtvs) ->
- let
- ve' = addListToUFM_Directly ve [(getUnique id, id) | id <- ids]
- in
- tcSetEnv (TcEnv te ve' gtvs) scope
+Constructing new Ids
-tcExtendLocalValEnv :: [(Name,TcId)] -> TcM s a -> TcM s a
-tcExtendLocalValEnv names_w_ids scope
- = tcGetEnv `thenNF_Tc` \ (TcEnv te ve (in_scope_tvs,gtvs)) ->
- tcReadMutVar gtvs `thenNF_Tc` \ global_tvs ->
- let
- ve' = addListToUFM ve names_w_ids
- extra_global_tyvars = tyVarsOfTypes (map (idType . snd) names_w_ids)
- in
- tc_extend_gtvs gtvs extra_global_tyvars `thenNF_Tc` \ gtvs' ->
- tcSetEnv (TcEnv te ve' (in_scope_tvs,gtvs')) scope
+\begin{code}
+newLocalName :: Name -> TcM Name
+newLocalName name -- Make a clone
+ = newUnique `thenM` \ uniq ->
+ returnM (mkInternalName uniq (getOccName name) (getSrcLoc name))
\end{code}
+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}
-tcLookupValue :: Name -> NF_TcM s Id -- Panics if not found
-tcLookupValue name
- = case maybeWiredInIdName name of
- Just id -> returnNF_Tc id
- Nothing -> tcGetEnv `thenNF_Tc` \ (TcEnv te ve gtvs) ->
- returnNF_Tc (lookupWithDefaultUFM ve def name)
+newDFunName :: Class -> [Type] -> SrcLoc -> TcM Name
+newDFunName clas (ty:_) loc
+ = newUnique `thenM` \ uniq ->
+ returnM (mkInternalName uniq (mkDFunOcc dfun_string) loc)
where
- def = pprPanic "tcLookupValue:" (ppr name)
-
-tcLookupValueMaybe :: Name -> NF_TcM s (Maybe Id)
-tcLookupValueMaybe name
- = case maybeWiredInIdName name of
- Just id -> returnNF_Tc (Just id)
- Nothing -> tcGetEnv `thenNF_Tc` \ (TcEnv te ve gtvs) ->
- returnNF_Tc (lookupUFM ve name)
-
-tcLookupValueByKey :: Unique -> NF_TcM s Id -- Panics if not found
-tcLookupValueByKey key
- = tcGetEnv `thenNF_Tc` \ (TcEnv te ve gtvs) ->
- returnNF_Tc (explicitLookupValueByKey ve key)
-
-tcLookupValueByKeyMaybe :: Unique -> NF_TcM s (Maybe Id)
-tcLookupValueByKeyMaybe key
- = tcGetEnv `thenNF_Tc` \ (TcEnv te ve gtvs) ->
- returnNF_Tc (lookupUFM_Directly ve key)
-
-tcGetValueEnv :: NF_TcM s ValueEnv
-tcGetValueEnv
- = tcGetEnv `thenNF_Tc` \ (TcEnv te ve gtvs) ->
- returnNF_Tc ve
-
-tcSetValueEnv :: ValueEnv -> TcM s a -> TcM s a
-tcSetValueEnv ve scope
- = tcGetEnv `thenNF_Tc` \ (TcEnv te _ gtvs) ->
- tcSetEnv (TcEnv te ve gtvs) scope
-
--- Non-monadic version, environment given explicitly
-explicitLookupValueByKey :: ValueEnv -> Unique -> Id
-explicitLookupValueByKey ve key
- = lookupWithDefaultUFM_Directly ve def key
- where
- def = pprPanic "lookupValueByKey:" (pprUnique10 key)
-
-explicitLookupValue :: ValueEnv -> Name -> Maybe Id
-explicitLookupValue ve name
- = case maybeWiredInIdName name of
- Just id -> Just id
- Nothing -> lookupUFM ve name
-
- -- Extract the IdInfo from an IfaceSig imported from an interface file
-tcAddImportedIdInfo :: ValueEnv -> 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 `setIdInfo` new_info
- -- The Id must be returned without a data dependency on maybe_id
- where
- new_info = -- pprTrace "tcAdd" (ppr id) $
- case explicitLookupValue unf_env (getName id) of
- Nothing -> noIdInfo
- Just imported_id -> idInfo imported_id
- -- ToDo: could check that types are the same
+ -- 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{Constructing new Ids}
+\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}
-newLocalId :: OccName -> TcType -> SrcLoc -> NF_TcM s TcId
-newLocalId name ty loc
- = tcGetUnique `thenNF_Tc` \ uniq ->
- returnNF_Tc (mkUserLocal name uniq ty loc)
-
-newSpecPragmaId :: Name -> TcType -> NF_TcM s TcId
-newSpecPragmaId name ty
- = tcGetUnique `thenNF_Tc` \ uniq ->
- returnNF_Tc (mkSpecPragmaId (nameOccName name) uniq ty (getSrcLoc name))
+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 _) = pprLHsBinds b
+ details (NewTypeDerived _) = text "Derived from the representation type"
+
+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}
%************************************************************************
\begin{code}
-badCon con_id
- = quotes (ppr con_id) <+> ptext SLIT("is not a data constructor")
-badPrimOp op
- = quotes (ppr op) <+> ptext SLIT("is not a primop")
+notFound wheRe name = failWithTc (text wheRe <> colon <+> quotes (ppr name) <+>
+ ptext SLIT("is not in scope"))
+
+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}
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