InstBindings(..),
-- Global environment
- tcExtendGlobalEnv,
+ tcExtendGlobalEnv, setGlobalTypeEnv,
tcExtendGlobalValEnv,
tcLookupLocatedGlobal, tcLookupGlobal,
tcLookupField, tcLookupTyCon, tcLookupClass, tcLookupDataCon,
tcGetGlobalTyVars,
-- Template Haskell stuff
- checkWellStaged, spliceOK, bracketOK, tcMetaTy, thLevel,
- topIdLvl, thTopLevelId,
+ checkWellStaged, tcMetaTy, thLevel,
+ topIdLvl, thTopLevelId, thRnBrack, isBrackStage,
-- New Ids
newLocalName, newDFunName, newFamInstTyConName,
-- import TcSuspension
import qualified Type
import Id
+import Coercion
import Var
import VarSet
import VarEnv
import TypeRep
import Class
import Name
-import PrelNames
import NameEnv
-import OccName
import HscTypes
import SrcLoc
import Outputable
-import Maybes
import Unique
import FastString
\end{code}
-- Should it have been in the local envt?
{ case nameModule_maybe name of
- Nothing -> notFound name env -- Internal names can happen in GHCi
+ Nothing -> notFound name -- Internal names can happen in GHCi
Just mod | mod == tcg_mod env -- Names from this module
- -> notFound name env -- should be in tcg_type_env
- | mod == thFAKE -- Names bound in TH declaration brackets
- -> notFound name env -- should be in tcg_env
+ -> notFound name -- should be in tcg_type_env
| otherwise
-> tcImportDecl name -- Go find it in an interface
}}}}}
tcLookupField :: Name -> TcM Id -- Returns the selector Id
-tcLookupField name = do
- thing <- tcLookup name -- Note [Record field lookup]
- case thing of
- AGlobal (AnId id) -> return id
- thing -> wrongThingErr "field name" thing name
+tcLookupField name
+ = tcLookupId name -- Note [Record field lookup]
{- Note [Record field lookup]
~~~~~~~~~~~~~~~~~~~~~~~~~~
and what is not) will rename the definition thus
f_7 = e { f_7 = True }
Now the type checker will find f_7 in the *local* type environment, not
-the global one. It's wrong, of course, but we want to report a tidy
+the global (imported) one. It's wrong, of course, but we want to report a tidy
error, not in TcEnv.notFound. -}
tcLookupDataCon :: Name -> TcM DataCon
-- Look up the instance tycon of a family instance.
--
--- The match must be unique - ie, match exactly one instance - but the
--- type arguments used for matching may be more specific than those of
--- the family instance declaration.
+-- The match may be ambiguous (as we know that overlapping instances have
+-- identical right-hand sides under overlapping substitutions - see
+-- 'FamInstEnv.lookupFamInstEnvConflicts'). However, the type arguments used
+-- for matching must be equal to or be more specific than those of the family
+-- instance declaration. We pick one of the matches in case of ambiguity; as
+-- the right-hand sides are identical under the match substitution, the choice
+-- does not matter.
--
-- Return the instance tycon and its type instance. For example, if we have
--
; eps <- getEps
; let instEnv = (eps_fam_inst_env eps, tcg_fam_inst_env env)
; case lookupFamInstEnv instEnv tycon tys of
- [(fam_inst, rep_tys)] -> return $ Just (famInstTyCon fam_inst,
- rep_tys)
- _ -> return Nothing
+ [] -> return Nothing
+ ((fam_inst, rep_tys):_)
+ -> return $ Just (famInstTyCon fam_inst, rep_tys)
}
\end{code}
+\begin{code}
+instance MonadThings (IOEnv (Env TcGblEnv TcLclEnv)) where
+ lookupThing = tcLookupGlobal
+\end{code}
+
%************************************************************************
%* *
Extending the global environment
\begin{code}
+setGlobalTypeEnv :: TcGblEnv -> TypeEnv -> TcM TcGblEnv
+-- Use this to update the global type env
+-- It updates both * the normal tcg_type_env field
+-- * the tcg_type_env_var field seen by interface files
+setGlobalTypeEnv tcg_env new_type_env
+ = do { -- Sync the type-envt variable seen by interface files
+ writeMutVar (tcg_type_env_var tcg_env) new_type_env
+ ; return (tcg_env { tcg_type_env = new_type_env }) }
+
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 }
+ = do { tcg_env <- getGblEnv
+ ; let ge' = extendTypeEnvList (tcg_type_env tcg_env) things
+ ; tcg_env' <- setGlobalTypeEnv tcg_env ge'
+ ; setGblEnv tcg_env' 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}
tcExtendRecEnv :: [(Name,TyThing)] -> TcM r -> TcM r
-- Extend the global environments for the type/class knot tying game
+-- Just like tcExtendGlobalEnv, except the argument is a list of pairs
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
+ = do { tcg_env <- getGblEnv
+ ; let ge' = extendNameEnvList (tcg_type_env tcg_env) gbl_stuff
+ ; tcg_env' <- setGlobalTypeEnv tcg_env ge'
+ ; setGblEnv tcg_env' thing_inside }
\end{code}
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 :: [LHsTyVarBndr Name] -> ([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]
+ = tcExtendKindEnv (map (hsTyVarNameKind . unLoc) bndrs)
+ (thing_inside bndrs)
tcExtendTyVarEnv :: [TyVar] -> TcM r -> TcM r
tcExtendTyVarEnv tvs thing_inside
tcl_tyvars = gtvs,
tcl_rdr = rdr_env}) <- getLclEnv
let
- rdr_env' = extendLocalRdrEnv rdr_env (map fst binds)
+ rdr_env' = extendLocalRdrEnvList rdr_env (map fst binds)
new_tv_set = tcTyVarsOfTypes (map snd binds)
le' = extendNameEnvList le [(name, ATyVar name ty) | (name, ty) <- binds]
_ -> Wobbly})
| (name,id) <- names_w_ids, let id_ty = idType id]
le' = extendNameEnvList (tcl_env env) extra_env
- rdr_env' = extendLocalRdrEnv (tcl_rdr env) [name | (name,_) <- names_w_ids]
+ rdr_env' = extendLocalRdrEnvList (tcl_rdr env) [name | (name,_) <- names_w_ids]
\end{code}
%************************************************************************
\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 (increases inside brackets)
- -> ThStage -- Use stage
+ -> ThLevel -- Use stage
-> TcM () -- Fail if badly staged, adding an error
-checkWellStaged pp_thing bind_lvl use_stage
+checkWellStaged pp_thing bind_lvl use_lvl
| use_lvl >= bind_lvl -- OK! Used later than bound
= return () -- E.g. \x -> [| $(f x) |]
- | bind_lvl == topLevel -- GHC restriction on top level splices
+ | bind_lvl == outerLevel -- 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"))]
+ nest 2 (vcat [ ptext (sLit "is used in a top-level splice or annotation,")
+ , ptext (sLit "and must be imported, not defined locally")])]
| otherwise -- Badly staged
= failWithTc $ -- E.g. \x -> $(f x)
ptext (sLit "Stage error:") <+> pp_thing <+>
hsep [ptext (sLit "is bound at stage") <+> ppr bind_lvl,
ptext (sLit "but used at stage") <+> ppr use_lvl]
- where
- use_lvl = thLevel use_stage
-
topIdLvl :: Id -> ThLevel
-- Globals may either be imported, or may be from an earlier "chunk"
-- $( f x )
-- By the time we are prcessing the $(f x), the binding for "x"
-- will be in the global env, not the local one.
-topIdLvl id | isLocalId id = topLevel
+topIdLvl id | isLocalId id = outerLevel
| otherwise = impLevel
--- Indicates the legal transitions on bracket( [| |] ).
-bracketOK :: ThStage -> Maybe ThLevel
-bracketOK (Brack _ _ _) = Nothing -- Bracket illegal inside a bracket
-bracketOK stage = Just (thLevel stage + 1)
-
--- Indicates the legal transitions on splice($).
-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
t <- tcLookupTyCon tc_name
return (mkTyConApp t [])
+thRnBrack :: ThStage
+-- Used *only* to indicate that we are inside a TH bracket during renaming
+-- Tested by TcEnv.isBrackStage
+-- See Note [Top-level Names in Template Haskell decl quotes]
+thRnBrack = Brack (panic "thRnBrack1") (panic "thRnBrack2") (panic "thRnBrack3")
+
+isBrackStage :: ThStage -> Bool
+isBrackStage (Brack {}) = True
+isBrackStage _other = False
+
thTopLevelId :: Id -> Bool
-- See Note [What is a top-level Id?] in TcSplice
thTopLevelId id = isGlobalId id || isExternalName (idName id)
(LHsBinds a) -- Bindings for the instance methods
[LSig a] -- User pragmas recorded for generating
-- specialised instances
+ Bool -- True <=> This code came from a standalone deriving clause
| NewTypeDerived -- Used for deriving instances of newtypes, where the
- -- witness dictionary is identical to the argument
+ CoercionI -- witness dictionary is identical to the argument
-- dictionary. Hence no bindings, no pragmas.
+ -- The coercion maps from newtype to the representation type
+ -- (mentioning type variables bound by the forall'd iSpec variables)
+ -- E.g. newtype instance N [a] = N1 (Tree a)
+ -- co : N [a] ~ Tree a
pprInstInfo :: InstInfo a -> SDoc
pprInstInfo info = vcat [ptext (sLit "InstInfo:") <+> ppr (idType (iDFunId info))]
pprInstInfoDetails :: OutputableBndr a => InstInfo a -> SDoc
pprInstInfoDetails info = pprInstInfo info $$ nest 2 (details (iBinds info))
where
- details (VanillaInst b _) = pprLHsBinds b
- details NewTypeDerived = text "Derived from the representation type"
+ details (VanillaInst b _ _) = pprLHsBinds b
+ details (NewTypeDerived _) = text "Derived from the representation type"
simpleInstInfoClsTy :: InstInfo a -> (Class, Type)
simpleInstInfoClsTy info = case instanceHead (iSpec info) of
\begin{code}
newDFunName :: Class -> [Type] -> SrcSpan -> TcM Name
-newDFunName clas (ty:_) loc
- = do { index <- nextDFunIndex
- ; is_boot <- tcIsHsBoot
+newDFunName clas tys loc
+ = do { is_boot <- tcIsHsBoot
; mod <- getModule
; let info_string = occNameString (getOccName clas) ++
- occNameString (getDFunTyKey ty)
- dfun_occ = mkDFunOcc info_string is_boot index
-
+ concatMap (occNameString.getDFunTyKey) tys
+ ; dfun_occ <- chooseUniqueOccTc (mkDFunOcc info_string is_boot)
; newGlobalBinder mod dfun_occ loc }
-
-newDFunName clas [] loc = pprPanic "newDFunName" (ppr clas <+> ppr loc)
\end{code}
Make a name for the representation tycon of a family instance. It's an
newGlobalBinder.
\begin{code}
-newFamInstTyConName :: Name -> SrcSpan -> TcM Name
-newFamInstTyConName tc_name loc
- = do { index <- nextDFunIndex
- ; mod <- getModule
- ; let occ = nameOccName tc_name
- ; newGlobalBinder mod (mkInstTyTcOcc index occ) loc }
+newFamInstTyConName :: Name -> [Type] -> SrcSpan -> TcM Name
+newFamInstTyConName tc_name tys loc
+ = do { mod <- getModule
+ ; let info_string = occNameString (getOccName tc_name) ++
+ concatMap (occNameString.getDFunTyKey) tys
+ ; occ <- chooseUniqueOccTc (mkInstTyTcOcc info_string)
+ ; newGlobalBinder mod occ loc }
\end{code}
Stable names used for foreign exports and annotations.
pprBinders [bndr] = quotes (ppr bndr)
pprBinders bndrs = pprWithCommas ppr bndrs
-notFound :: Name -> TcGblEnv -> TcM TyThing
-notFound name env
- = failWithTc (vcat[ptext (sLit "GHC internal error:") <+> quotes (ppr name) <+>
+notFound :: Name -> TcM TyThing
+notFound name
+ = do { (gbl,lcl) <- getEnvs
+ ; failWithTc (vcat[ptext (sLit "GHC internal error:") <+> quotes (ppr name) <+>
ptext (sLit "is not in scope during type checking, but it passed the renamer"),
- ptext (sLit "tcg_type_env of environment:") <+> ppr (tcg_type_env env)]
- )
+ ptext (sLit "tcg_type_env of environment:") <+> ppr (tcg_type_env gbl),
+ ptext (sLit "tcl_env of environment:") <+> ppr (tcl_env lcl)]
+ ) }
wrongThingErr :: String -> TcTyThing -> Name -> TcM a
wrongThingErr expected thing name