\begin{code}
module TcEnv(
- TcId, TcIdSet,
- TyThing(..), TyThingDetails(..),
+ TyThing(..), TcTyThing(..), TcId,
- -- Getting stuff from the environment
- TcEnv, initTcEnv,
- tcEnvTyCons, tcEnvClasses, tcEnvIds, tcEnvTcIds,
-
- -- Instance environment
- tcGetInstEnv, tcSetInstEnv,
+ -- Instance environment, and InstInfo type
+ InstInfo(..), iDFunId, pprInstInfo, pprInstInfoDetails,
+ simpleInstInfoClsTy, simpleInstInfoTy, simpleInstInfoTyCon,
+ InstBindings(..),
-- Global environment
- tcExtendGlobalEnv, tcExtendGlobalValEnv,
- tcLookupTy, tcLookupTyCon, tcLookupClass, tcLookupGlobalId, tcLookupDataCon,
-
+ tcExtendGlobalEnv,
+ tcExtendGlobalValEnv,
+ tcLookupLocatedGlobal, tcLookupGlobal,
+ tcLookupGlobalId, tcLookupTyCon, tcLookupClass, tcLookupDataCon,
+ tcLookupLocatedGlobalId, tcLookupLocatedTyCon,
+ tcLookupLocatedClass,
+
-- Local environment
- tcExtendKindEnv,
- tcExtendTyVarEnv, tcExtendTyVarEnvForMeths,
- tcExtendLocalValEnv,
+ tcExtendKindEnv, tcExtendKindEnvTvs,
+ tcExtendTyVarEnv, tcExtendTyVarEnv2,
+ tcExtendIdEnv, tcExtendIdEnv1, tcExtendIdEnv2,
+ tcLookup, tcLookupLocated, tcLookupLocalIds, tcLookupLocalId_maybe,
+ tcLookupId, tcLookupTyVar, getScopedTyVarBinds,
+ lclEnvElts, getInLocalScope, findGlobals,
+ wrongThingErr, pprBinders,
+ refineEnvironment,
+
+ tcExtendRecEnv, -- For knot-tying
+
+ -- Rules
+ tcExtendRules,
-- Global type variables
- tcGetGlobalTyVars, tcExtendGlobalTyVars,
+ tcGetGlobalTyVars,
- -- Random useful things
- tcAddImportedIdInfo, tcInstId,
+ -- Template Haskell stuff
+ checkWellStaged, spliceOK, bracketOK, tcMetaTy, thLevel,
+ topIdLvl,
-- New Ids
- newLocalId, newSpecPragmaId,
- newDefaultMethodName, newDFunName
+ newLocalName, newDFunName
) where
#include "HsVersions.h"
-import TcMonad
-import TcType ( TcKind, TcType, TcTyVar, TcTyVarSet, TcThetaType,
- tcInstTyVars, zonkTcTyVars,
- )
-import Id ( mkUserLocal, isDataConWrapId_maybe )
-import IdInfo ( vanillaIdInfo )
-import MkId ( mkSpecPragmaId )
-import Var ( TyVar, Id, setVarName,
- idType, lazySetIdInfo, idInfo, tyVarKind, UVar,
- )
+import HsSyn ( LRuleDecl, LHsBinds, LSig,
+ LHsTyVarBndr, HsTyVarBndr(..), pprLHsBinds )
+import TcIface ( tcImportDecl )
+import IfaceEnv ( newGlobalBinder )
+import TcRnMonad
+import TcMType ( zonkTcType, zonkTcTyVarsAndFV )
+import TcType ( Type, TcKind, TcTyVar, TcTyVarSet, TcType, TvSubst,
+ substTy, substTyVar, tyVarsOfType, tcTyVarsOfTypes, mkTyConApp,
+ getDFunTyKey, tcTyConAppTyCon, tcGetTyVar, mkTyVarTy,
+ tidyOpenType, isRefineableTy
+ )
+import qualified Type ( getTyVar_maybe )
+import Id ( idName, isLocalId, setIdType )
+import Var ( TyVar, Id, idType, tyVarName )
import VarSet
-import VarEnv ( TyVarSubstEnv )
-import Type ( Kind, Type, superKind,
- tyVarsOfType, tyVarsOfTypes,
- splitForAllTys, splitRhoTy, splitFunTys,
- splitAlgTyConApp_maybe, getTyVar, getDFunTyKey
- )
-import DataCon ( DataCon )
-import TyCon ( TyCon, tyConKind, tyConArity, isSynTyCon )
-import Class ( Class, ClassOpItem, ClassContext, classTyCon )
-import Subst ( substTy )
-import Name ( Name, OccName, Provenance(..), ExportFlag(..), NamedThing(..),
- nameOccName, nameModule, getSrcLoc, mkGlobalName,
- maybeWiredInTyConName, maybeWiredInIdName, isLocallyDefined,
- NameEnv, emptyNameEnv, lookupNameEnv, nameEnvElts,
- extendNameEnv, extendNameEnvList
- )
-import OccName ( mkDFunOcc, mkDefaultMethodOcc, occNameString )
-import Module ( Module )
-import Unify ( unifyTyListsX, matchTys )
-import HscTypes ( ModDetails(..), lookupTypeEnv )
-import Unique ( pprUnique10, Unique, Uniquable(..) )
-import UniqFM
-import Unique ( Uniquable(..) )
-import Util ( zipEqual, zipWith3Equal, mapAccumL )
-import SrcLoc ( SrcLoc )
-import FastString ( FastString )
-import Maybes
+import VarEnv
+import RdrName ( extendLocalRdrEnv )
+import InstEnv ( Instance, DFunId, instanceDFunId, instanceHead )
+import DataCon ( DataCon )
+import TyCon ( TyCon )
+import Class ( Class )
+import Name ( Name, NamedThing(..), getSrcLoc, nameModule, isExternalName )
+import PrelNames ( thFAKE )
+import NameEnv
+import OccName ( mkDFunOcc, occNameString )
+import HscTypes ( extendTypeEnvList, lookupType,
+ TyThing(..), tyThingId, tyThingDataCon,
+ ExternalPackageState(..) )
+
+import SrcLoc ( SrcLoc, Located(..) )
import Outputable
\end{code}
+
%************************************************************************
%* *
-\subsection{TcEnv}
+%* tcLookupGlobal *
%* *
%************************************************************************
-\begin{code}
-type TcId = Id -- Type may be a TcType
-type TcIdSet = IdSet
+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.
-data TcEnv
- = TcEnv {
- tcGST :: GlobalSymbolTable, -- The symbol table at the moment we began this compilation
+\begin{code}
+tcLookupLocatedGlobal :: Located Name -> TcM TyThing
+-- c.f. IfaceEnvEnv.tcIfaceGlobal
+tcLookupLocatedGlobal name
+ = addLocM tcLookupGlobal name
+
+tcLookupGlobal :: Name -> TcM TyThing
+-- The Name is almost always an ExternalName, but not always
+-- In GHCi, we may make command-line bindings (ghci> let x = True)
+-- that bind a GlobalId, but with an InternalName
+tcLookupGlobal name
+ = do { env <- getGblEnv
+
+ -- Try local envt
+ ; case lookupNameEnv (tcg_type_env env) name of {
+ Just thing -> return thing ;
+ Nothing -> do
+
+ -- Try global envt
+ { (eps,hpt) <- getEpsAndHpt
+ ; case lookupType hpt (eps_PTE eps) name of {
+ Just thing -> return thing ;
+ Nothing -> do
+
+ -- Should it have been in the local envt?
+ { let mod = nameModule name
+ ; if mod == tcg_mod env || mod == thFAKE then
+ notFound name -- It should be local, so panic
+ -- The thFAKE possibility is because it
+ -- might be in a declaration bracket
+ else
+ tcImportDecl name -- Go find it in an interface
+ }}}}}
+
+tcLookupGlobalId :: Name -> TcM Id
+-- Never used for Haskell-source DataCons, hence no ADataCon case
+tcLookupGlobalId name
+ = tcLookupGlobal name `thenM` \ thing ->
+ return (tyThingId thing)
- tcInst :: InstEnv, -- All instances (both imported and in this module)
+tcLookupDataCon :: Name -> TcM DataCon
+tcLookupDataCon con_name
+ = tcLookupGlobal con_name `thenM` \ thing ->
+ return (tyThingDataCon thing)
- tcGEnv :: NameEnv TyThing -- The global type environment we've accumulated while
- -- compiling this module:
- -- types and classes (both imported and local)
- -- imported Ids
- -- (Ids defined in this module are in the local envt)
+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
- tcLEnv :: NameEnv TcTyThing, -- The local type environment: Ids and TyVars
- -- defined in this module
+tcLookupLocatedGlobalId :: Located Name -> TcM Id
+tcLookupLocatedGlobalId = addLocM tcLookupId
- tcTyVars :: TcRef TcTyVarSet -- The "global tyvars"
- -- Namely, the in-scope TyVars bound in tcLEnv, plus the tyvars
- -- mentioned in the types of Ids bound in tcLEnv
- -- Why mutable? see notes with tcGetGlobalTyVars
- }
+tcLookupLocatedClass :: Located Name -> TcM Class
+tcLookupLocatedClass = addLocM tcLookupClass
+tcLookupLocatedTyCon :: Located Name -> TcM TyCon
+tcLookupLocatedTyCon = addLocM tcLookupTyCon
\end{code}
-The Global-Env/Local-Env story
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-During type checking, we keep in the GlobalEnv
- * All types and classes
- * All Ids derived from types and classes (constructors, selectors)
- * Imported Ids
-
-At the end of type checking, we zonk the local bindings,
-and as we do so we add to the GlobalEnv
- * Locally defined top-level Ids
+%************************************************************************
+%* *
+ Extending the global environment
+%* *
+%************************************************************************
-Why? Because they are now Ids not TcIds. This final GlobalEnv is
-used thus:
- a) fed back (via the knot) to typechecking the
- unfoldings of interface signatures
- b) used to augment the GlobalSymbolTable
+\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}
\begin{code}
-data TcTyThing
- = AGlobal TyThing -- Used only in the return type of a lookup
- | ATcId TcId -- Ids defined in this module
- | ATyVar TyVar -- Type variables
- | AThing TcKind -- Used temporarily, during kind checking
--- Here's an example of how the AThing guy is used
--- Suppose we are checking (forall a. T a Int):
--- 1. We first bind (a -> AThink kv), where kv is a kind variable.
--- 2. Then we kind-check the (T a Int) part.
--- 3. Then we zonk the kind variable.
--- 4. Now we know the kind for 'a', and we add (a -> ATyVar a::K) to the environment
-
-initTcEnv :: GlobalSymbolTable -> InstEnv -> IO TcEnv
-initTcEnv gst inst_env
- = do { gtv_var <- newIORef emptyVarSet
- return (TcEnv { tcGST = gst,
- tcGEnv = emptyNameEnv,
- tcInst = inst_env,
- tcLEnv = emptyNameEnv,
- tcTyVars = gtv_var
- })}
-
-tcEnvClasses env = [cl | AClass cl <- nameEnvElts (tcGEnv env)]
-tcEnvTyCons env = [tc | ATyCon tc <- nameEnvElts (tcGEnv env)]
-tcEnvIds env = [id | AnId id <- nameEnvElts (tcGEnv env)]
-tcEnvTyVars env = [tv | ATyVar tv <- nameEnvElts (tcLEnv env)]
-tcEnvTcIds env = [id | ATcId id <- nameEnvElts (tcLEnv env)]
-
--- This data type is used to help tie the knot
--- when type checking type and class declarations
-data TyThingDetails = SynTyDetails Type
- | DataTyDetails ClassContext [DataCon] [Class]
- | ClassDetails ClassContext [Id] [ClassOpItem] DataCon
+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{Basic lookups}
+\subsection{The local environment}
%* *
%************************************************************************
\begin{code}
-lookup_global :: TcEnv -> Name -> Maybe TyThing
- -- Try the global envt and then the global symbol table
-lookup_global env name
- = case lookupNameEnv (tcGEnv env) name of {
- Just thing -> Just thing ;
- Nothing -> lookupTypeEnv (tcGST env) name
-
-lookup_local :: TcEnv -> Name -> Maybe TcTyThing
- -- Try the local envt and then try the global
-lookup_local env name
- = case lookupNameEnv (tcLEnv env) name of
- Just thing -> Just thing ;
- Nothing -> case lookup_global env name of
- Just thing -> AGlobal thing
- Nothing -> Nothing
-
-explicitLookupId :: TcEnv -> Name -> Maybe Id
-explicitLookupId env name = case lookup_global env name of
- Just (AnId id) -> Just id
- other -> Nothing
-\end{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 TcTyVar
+tcLookupTyVar name
+ = tcLookup name `thenM` \ thing ->
+ case thing of
+ ATyVar _ ty -> return (tcGetTyVar "tcLookupTyVar" ty)
+ 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)
+
+tcLookupLocalId_maybe :: Name -> TcM (Maybe Id)
+tcLookupLocalId_maybe name
+ = getLclEnv `thenM` \ local_env ->
+ case lookupNameEnv (tcl_env local_env) name of
+ Just (ATcId tc_id _ _) -> return (Just tc_id)
+ other -> return Nothing
+
+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}
-%************************************************************************
-%* *
-\subsection{Random useful functions}
-%* *
-%************************************************************************
+\begin{code}
+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]
+tcExtendKindEnvTvs :: [LHsTyVarBndr Name] -> TcM r -> TcM r
+tcExtendKindEnvTvs bndrs thing_inside
+ = updLclEnv upd thing_inside
+ where
+ upd lcl_env = lcl_env { tcl_env = extend (tcl_env lcl_env) }
+ extend env = extendNameEnvList env pairs
+ pairs = [(n, AThing k) | L _ (KindedTyVar n k) <- bndrs]
-\begin{code}
--- A useful function that takes an occurrence of a global thing
--- and instantiates its type with fresh type variables
-tcInstId :: Id
- -> NF_TcM ([TcTyVar], -- It's instantiated type
- TcThetaType, --
- TcType) --
-tcInstId id
- = let
- (tyvars, rho) = splitForAllTys (idType id)
- in
- tcInstTyVars tyvars `thenNF_Tc` \ (tyvars', arg_tys, tenv) ->
+tcExtendTyVarEnv :: [TyVar] -> TcM r -> TcM r
+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}) ->
let
- rho' = substTy tenv rho
- (theta', tau') = splitRhoTy rho'
+ 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
- returnNF_Tc (tyvars', theta', tau')
-
-tcAddImportedIdInfo :: TcEnv -> 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 `lazySetIdInfo` new_info
- -- The Id must be returned without a data dependency on maybe_id
- where
- new_info = case explicitLookupId unf_env (getName id) of
- Nothing -> vanillaIdInfo
- Just imported_id -> idInfo imported_id
- -- ToDo: could check that types are the same
-\end{code}
-
+ -- 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
-%************************************************************************
-%* *
-\subsection{Making new Ids}
-%* *
-%************************************************************************
+getScopedTyVarBinds :: TcM [(Name, TcType)]
+getScopedTyVarBinds
+ = do { lcl_env <- getLclEnv
+ ; return [(name, ty) | ATyVar name ty <- nameEnvElts (tcl_env lcl_env)] }
+\end{code}
-Constructing new Ids
\begin{code}
-newLocalId :: OccName -> TcType -> SrcLoc -> NF_TcM TcId
-newLocalId name ty loc
- = tcGetUnique `thenNF_Tc` \ uniq ->
- returnNF_Tc (mkUserLocal name uniq ty loc)
-
-newSpecPragmaId :: Name -> TcType -> NF_TcM TcId
-newSpecPragmaId name ty
- = tcGetUnique `thenNF_Tc` \ uniq ->
- returnNF_Tc (mkSpecPragmaId (nameOccName name) uniq ty (getSrcLoc name))
+tcExtendIdEnv :: [TcId] -> TcM a -> TcM a
+-- Invariant: the TcIds are fully zonked. Reasons:
+-- (a) The kinds of the forall'd type variables are defaulted
+-- (see Kind.defaultKind, done in zonkQuantifiedTyVar)
+-- (b) There are no via-Indirect occurrences of the bound variables
+-- in the types, because instantiation does not look through such things
+-- (c) The call to tyVarsOfTypes is ok without looking through refs
+tcExtendIdEnv ids thing_inside = tcExtendIdEnv2 [(idName id, id) | id <- ids] thing_inside
+
+tcExtendIdEnv1 :: Name -> TcId -> TcM a -> TcM a
+tcExtendIdEnv1 name id thing_inside = tcExtendIdEnv2 [(name,id)] thing_inside
+
+tcExtendIdEnv2 :: [(Name,TcId)] -> TcM a -> TcM a
+-- Invariant: the TcIds are fully zonked (see tcExtendIdEnv above)
+tcExtendIdEnv2 names_w_ids thing_inside
+ = getLclEnv `thenM` \ env ->
+ let
+ extra_global_tyvars = tcTyVarsOfTypes [idType id | (_,id) <- names_w_ids]
+ th_lvl = thLevel (tcl_th_ctxt env)
+ extra_env = [ (name, ATcId id th_lvl (isRefineableTy (idType id)))
+ | (name,id) <- names_w_ids]
+ le' = extendNameEnvList (tcl_env env) extra_env
+ rdr_env' = extendLocalRdrEnv (tcl_rdr env) [name | (name,_) <- names_w_ids]
+ in
+ traceTc (text "env2") `thenM_`
+ traceTc (text "env3" <+> ppr extra_env) `thenM_`
+ tc_extend_gtvs (tcl_tyvars env) extra_global_tyvars `thenM` \ gtvs' ->
+ (traceTc (text "env4") `thenM_`
+ setLclEnv (env {tcl_env = le', tcl_tyvars = gtvs', tcl_rdr = rdr_env'}) thing_inside)
\end{code}
-Make a name for the dict fun for an instance decl
\begin{code}
-newDFunName :: Module -> Class -> [Type] -> SrcLoc -> NF_TcM Name
-newDFunName mod clas (ty:_) loc
- = tcGetDFunUniq dfun_string `thenNF_Tc` \ inst_uniq ->
- tcGetUnique `thenNF_Tc` \ uniq ->
- returnNF_Tc (mkGlobalName uniq mod
- (mkDFunOcc dfun_string inst_uniq)
- (LocalDef loc Exported))
+-----------------------
+-- 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
- -- Any string that is somewhat unique will do
- dfun_string = occNameString (getOccName clas) ++ occNameString (getDFunTyKey ty)
-
-newDefaultMethodName :: Name -> SrcLoc -> NF_TcM Name
-newDefaultMethodName op_name loc
- = tcGetUnique `thenNF_Tc` \ uniq ->
- returnNF_Tc (mkGlobalName uniq (nameModule op_name)
- (mkDefaultMethodOcc (getOccName op_name))
- (LocalDef loc Exported))
+ 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 ty)
+ = zonkTcType ty `thenM` \ tv_ty ->
+ if ignore_it tv_ty then
+ returnM (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]
+
+ 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)
\end{code}
+\begin{code}
+refineEnvironment :: TvSubst -> TcM a -> TcM a
+refineEnvironment reft thing_inside
+ = do { env <- getLclEnv
+ ; let le' = mapNameEnv refine (tcl_env env)
+ ; gtvs' <- refineGlobalTyVars reft (tcl_tyvars env)
+ ; setLclEnv (env {tcl_env = le', tcl_tyvars = gtvs'}) thing_inside }
+ where
+ refine (ATcId id lvl True) = ATcId (setIdType id (substTy reft (idType id))) lvl True
+ refine (ATyVar tv ty) = ATyVar tv (substTy reft ty)
+ refine elt = elt
+\end{code}
%************************************************************************
%* *
-\subsection{The global environment}
+\subsection{The global tyvars}
%* *
%************************************************************************
\begin{code}
-tcExtendGlobalEnv :: [(Name, TyThing)] -> TcM r -> TcM r
-tcExtendGlobalEnv bindings thing_inside
- = tcGetEnv `thenNF_Tc` \ env ->
- let
- ge' = extendNameEnvList (tcGEnv env) bindings
- in
- tcSetEnv (env {tcGEnv = ge'}) thing_inside
+tc_extend_gtvs gtvs extra_global_tvs
+ = readMutVar gtvs `thenM` \ global_tvs ->
+ newMutVar (global_tvs `unionVarSet` extra_global_tvs)
-tcExtendGlobalValEnv :: [Id] -> TcM a -> TcM a
-tcExtendGlobalValEnv ids thing_inside
- = tcExtendGlobalEnv [(getName id, AnId id) | id <- ids] thing_inside
+refineGlobalTyVars :: GadtRefinement -> TcRef TcTyVarSet -> TcM (TcRef TcTyVarSet)
+refineGlobalTyVars reft gtv_var
+ = readMutVar gtv_var `thenM` \ gbl_tvs ->
+ newMutVar (tcTyVarsOfTypes (map (substTyVar reft) (varSetElems gbl_tvs)))
\end{code}
+@tcGetGlobalTyVars@ returns a fully-zonked set of tyvars free in the environment.
+To improve subsequent calls to the same function it writes the zonked set back into
+the environment.
\begin{code}
-tcLookupGlobal_maybe :: Name -> NF_TcM (Maybe TyThing)
-tcLookupGlobal_maybe name
- = tcGetEnv `thenNF_Tc` \ env ->
- returnNF_Tc (lookup_global env name)
+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'
\end{code}
-A variety of global lookups, when we know what we are looking for.
+
+%************************************************************************
+%* *
+\subsection{Rules}
+%* *
+%************************************************************************
\begin{code}
-tcLookupGlobal :: Name -> NF_TcM TyThing
- = tcLookupGlobal_maybe name `thenNF_Tc` \ maybe_thing ->
- case maybe_thing of
- Just thing -> returnNF_Tc thing
- other -> notFound "tcLookupGlobal:" 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}
-tcLookupGlobalId :: Name -> NF_TcM Id
-tcLookupGlobalId name
- = tcLookupGlobal_maybe name `thenNF_Tc` \ maybe_id ->
- case maybe_id of
- Just (AnId clas) -> returnNF_Tc id
- other -> notFound "tcLookupGlobalId:" name
-
-tcLookupDataCon :: Name -> TcM DataCon
-tcLookupDataCon con_name
- = tcLookupGlobalId con_name `thenNF_Tc` \ con_id ->
- case isDataConWrapId_maybe con_id of {
- Just data_con -> returnTc data_con
- Nothing -> failWithTc (badCon con_id);
+%************************************************************************
+%* *
+ Meta level
+%* *
+%************************************************************************
-tcLookupClass :: Name -> NF_TcM Class
-tcLookupClass name
- = tcLookupGlobal_maybe name `thenNF_Tc` \ maybe_clas ->
- case maybe_clas of
- Just (AClass clas) -> returnNF_Tc clas
- other -> notFound "tcLookupClass:" name
-
-tcLookupTyCon :: Name -> NF_TcM TyCon
-tcLookupTyCon name
- = tcLookupGlobal_maybe name `thenNF_Tc` \ maybe_tc ->
- case maybe_tc of
- Just (ATyCon tc) -> returnNF_Tc tc
- other -> notFound "tcLookupTyCon:" name
+\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 (mkTyConApp t [])
\end{code}
%************************************************************************
%* *
-\subsection{The local environment}
+\subsection{The InstInfo type}
%* *
%************************************************************************
-\begin{code}
-tcLookup_maybe :: Name -> NF_TcM (Maybe TcTyThing)
-tcLookup_maybe name
- = tcGetEnv `thenNF_Tc` \ env ->
- returnNF_Tc (lookup_local env name)
+The InstInfo type summarises the information in an instance declaration
-tcLookup :: Name -> NF_TcM TcTyThing
-tcLookup name
- = tcLookup_maybe name `thenNF_Tc` \ maybe_thing ->
- case maybe_thing of
- Just thing -> returnNF_Tc thing
- other -> notFound "tcLookup:" name
- -- Extract the IdInfo from an IfaceSig imported from an interface file
-\end{code}
+ 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}
-tcExtendKindEnv :: [(Name,TcKind)] -> TcM r -> TcM r
-tcExtendKindEnv pairs thing_inside
- = tcGetEnv `thenNF_Tc` \ env ->
- let
- le' = extendNameEnvList (tcLEnv env) [(n, AThing k) | (n,k) <- pairs]
- -- No need to extend global tyvars for kind checking
- in
- tcSetEnv (env {tcLEnv = le'}) thing_inside
-
-tcExtendTyVarEnv :: [TyVar] -> TcM r -> TcM r
-tcExtendTyVarEnv tyvars thing_inside
- = tcGetEnv `thenNF_Tc` \ env@(TcEnv {tcLEnv = le, tcTyVars = gtvs}) ->
- let
- le' = extendNameEnvList le [ (getName tv, ATyVar tv) | tv <- tyvars]
- 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 ...
- -- 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 (env {tcLEnv = le', tcTyVars = gtvs'}) thing_inside
-
--- 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 r -> TcM r
-tcExtendTyVarEnvForMeths sig_tyvars inst_tyvars thing_inside
- = tcGetEnv `thenNF_Tc` \ env ->
- let
- le' = extendNameEnvList (tcLEnv env) stuff
- stuff = [ (getName sig_tv, ATyVar inst_tv)
- | (sig_tv, inst_tv) <- zipEqual "tcMeth" sig_tyvars inst_tyvars
- ]
- in
- tcSetEnv (env {tcLEnv = le'}) thing_inside
-\end{code}
+data InstInfo
+ = InstInfo {
+ iSpec :: Instance, -- Includes the dfun id. Its forall'd type
+ iBinds :: InstBindings -- variables scope over the stuff in InstBindings!
+ }
+iDFunId :: InstInfo -> DFunId
+iDFunId info = instanceDFunId (iSpec info)
-\begin{code}
-tcExtendLocalValEnv :: [(Name,TcId)] -> TcM a -> TcM a
-tcExtendLocalValEnv names_w_ids thing_inside
- = tcGetEnv `thenNF_Tc` \ env ->
- let
- extra_global_tyvars = tyVarsOfTypes [idType id | (name,id) <- names_w_ids]
- extra_env = [(name, ATcId id) | (name,id) <- names_w_ids]
- le' = extendNameEnvList (tcLEnv env) extra_env
- in
- tc_extend_gtvs (tcTyVars env) extra_global_tyvars `thenNF_Tc` \ gtvs' ->
- tcSetEnv (env {tcLEnv = le', tcTyVars = gtvs'}) thing_inside
-\end{code}
+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
-%************************************************************************
-%* *
-\subsection{The global tyvars}
-%* *
-%************************************************************************
+pprInstInfo info = vcat [ptext SLIT("InstInfo:") <+> ppr (idType (iDFunId info))]
-\begin{code}
-tcExtendGlobalTyVars extra_global_tvs thing_inside
- = tcGetEnv `thenNF_Tc` \ env ->
- tc_extend_gtvs (tcTyVars env) extra_global_tvs `thenNF_Tc` \ gtvs' ->
- tcSetEnv (env {tcTyVars = gtvs') thing_inside
+pprInstInfoDetails info = pprInstInfo info $$ nest 2 (details (iBinds info))
+ where
+ details (VanillaInst b _) = pprLHsBinds b
+ details (NewTypeDerived _) = text "Derived from the representation type"
-tc_extend_gtvs gtvs extra_global_tvs
- = tcReadMutVar gtvs `thenNF_Tc` \ global_tvs ->
- tcNewMutVar (global_tvs `unionVarSet` extra_global_tvs)
-\end{code}
+simpleInstInfoClsTy :: InstInfo -> (Class, Type)
+simpleInstInfoClsTy info = case instanceHead (iSpec info) of
+ (_, _, cls, [ty]) -> (cls, ty)
-@tcGetGlobalTyVars@ returns a fully-zonked set of tyvars free in the environment.
-To improve subsequent calls to the same function it writes the zonked set back into
-the environment.
+simpleInstInfoTy :: InstInfo -> Type
+simpleInstInfoTy info = snd (simpleInstInfoClsTy info)
-\begin{code}
-tcGetGlobalTyVars :: NF_TcM TcTyVarSet
-tcGetGlobalTyVars
- = tcGetEnv `thenNF_Tc` \ (TcEnv {tcTyVars = gtv_var}) ->
- tcReadMutVar gtv_var `thenNF_Tc` \ global_tvs ->
- zonkTcTyVars (varSetElems global_tvs) `thenNF_Tc` \ global_tys' ->
- let
- global_tvs' = (tyVarsOfTypes global_tys')
- in
- tcWriteMutVar gtv_var global_tvs' `thenNF_Tc_`
- returnNF_Tc global_tvs'
+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{The instance environment}
-%* *
-%************************************************************************
+Make a name for the dict fun for an instance decl. It's an *external*
+name, like otber top-level names, and hence must be made with newGlobalBinder.
\begin{code}
-tcGetInstEnv :: NF_TcM InstEnv
-tcGetInstEnv = tcGetEnv `thenNF_Tc` \ env ->
- returnNF_Tc (tcInst env)
-
-tcSetInstEnv :: InstEnv -> TcM a -> TcM a
-tcSetInstEnv ie thing_inside
- = tcGetEnv `thenNF_Tc` \ env ->
- tcSetEnv (env {tcInst = ie}) thing_inside
-\end{code}
+newDFunName :: Class -> [Type] -> SrcLoc -> TcM Name
+newDFunName clas (ty:_) loc
+ = do { index <- nextDFunIndex
+ ; is_boot <- tcIsHsBoot
+ ; mod <- getModule
+ ; let info_string = occNameString (getOccName clas) ++
+ occNameString (getDFunTyKey ty)
+ dfun_occ = mkDFunOcc info_string is_boot index
+
+ ; newGlobalBinder mod dfun_occ Nothing loc }
+
+newDFunName clas [] loc = pprPanic "newDFunName" (ppr clas <+> ppr loc)
+\end{code}
%************************************************************************
%************************************************************************
\begin{code}
-badCon con_id = quotes (ppr con_id) <+> ptext SLIT("is not a data constructor")
-
-notFound where name = failWithTc (text where <> colon <+> quotes (ppr name) <+>
- ptext SLIT("is not in scope"))
+pprBinders :: [Name] -> SDoc
+-- Used in error messages
+-- Use quotes for a single one; they look a bit "busy" for several
+pprBinders [bndr] = quotes (ppr bndr)
+pprBinders bndrs = pprWithCommas ppr bndrs
+
+notFound name
+ = failWithTc (ptext SLIT("GHC internal error:") <+> quotes (ppr name) <+>
+ ptext SLIT("is not in scope"))
+
+wrongThingErr expected thing name
+ = failWithTc (pprTcTyThingCategory thing <+> quotes (ppr name) <+>
+ ptext SLIT("used as a") <+> text expected)
\end{code}
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