module TcEnv(
TyThing(..), TcTyThing(..), TcId,
InstInfo(..), iDFunId, pprInstInfoDetails,
simpleInstInfoClsTy, simpleInstInfoTy, simpleInstInfoTyCon,
InstBindings(..),
tcExtendGlobalEnv, tcExtendGlobalEnvImplicit, setGlobalTypeEnv,
tcExtendGlobalValEnv,
tcLookupLocatedGlobal, tcLookupGlobal,
tcLookupField, tcLookupTyCon, tcLookupClass,
tcLookupDataCon, tcLookupPatSyn, tcLookupConLike,
tcLookupLocatedGlobalId, tcLookupLocatedTyCon,
tcLookupLocatedClass, tcLookupAxiom,
tcExtendKindEnv, tcExtendKindEnv2,
tcExtendTyVarEnv, tcExtendTyVarEnv2,
tcExtendLetEnv,
tcExtendIdEnv, tcExtendIdEnv1, tcExtendIdEnv2, tcExtendIdEnv3,
tcExtendIdBndrs, tcExtendGhciIdEnv,
tcLookup, tcLookupLocated, tcLookupLocalIds,
tcLookupId, tcLookupTyVar,
tcLookupLcl_maybe,
getScopedTyVarBinds, getInLocalScope,
wrongThingErr, pprBinders,
tcExtendRecEnv,
tcLookupInstance, tcGetInstEnvs,
tcExtendRules,
tcGetDefaultTys,
tcGetGlobalTyVars, zapLclTypeEnv,
checkWellStaged, tcMetaTy, thLevel,
topIdLvl, isBrackStage,
newLocalName, newDFunName, newFamInstTyConName, newFamInstAxiomName,
mkStableIdFromString, mkStableIdFromName,
mkWrapperName
) where
#include "HsVersions.h"
import HsSyn
import IfaceEnv
import TcRnMonad
import TcMType
import TcType
import LoadIface
import PrelNames
import TysWiredIn
import Id
import IdInfo( IdDetails(VanillaId) )
import Var
import VarSet
import RdrName
import InstEnv
import DataCon ( DataCon )
import PatSyn ( PatSyn )
import ConLike
import TyCon
import CoAxiom
import TypeRep
import Class
import Name
import NameEnv
import VarEnv
import HscTypes
import DynFlags
import SrcLoc
import BasicTypes hiding( SuccessFlag(..) )
import Module
import Outputable
import Encoding
import FastString
import ListSetOps
import Util
import Maybes( MaybeErr(..) )
import Data.IORef
import Data.List
tcLookupLocatedGlobal :: Located Name -> TcM TyThing
tcLookupLocatedGlobal name
= addLocM tcLookupGlobal name
tcLookupGlobal :: Name -> TcM TyThing
tcLookupGlobal name
= do {
env <- getGblEnv
; case lookupNameEnv (tcg_type_env env) name of {
Just thing -> return thing ;
Nothing ->
if nameIsLocalOrFrom (tcg_mod env) name
then notFound name
else
do { mb_thing <- tcLookupImported_maybe name
; case mb_thing of
Succeeded thing -> return thing
Failed msg -> failWithTc msg
}}}
tcLookupField :: Name -> TcM Id
tcLookupField name
= tcLookupId name
tcLookupDataCon :: Name -> TcM DataCon
tcLookupDataCon name = do
thing <- tcLookupGlobal name
case thing of
AConLike (RealDataCon con) -> return con
_ -> wrongThingErr "data constructor" (AGlobal thing) name
tcLookupPatSyn :: Name -> TcM PatSyn
tcLookupPatSyn name = do
thing <- tcLookupGlobal name
case thing of
AConLike (PatSynCon ps) -> return ps
_ -> wrongThingErr "pattern synonym" (AGlobal thing) name
tcLookupConLike :: Name -> TcM ConLike
tcLookupConLike name = do
thing <- tcLookupGlobal name
case thing of
AConLike cl -> return cl
_ -> wrongThingErr "constructor-like thing" (AGlobal thing) name
tcLookupClass :: Name -> TcM Class
tcLookupClass name = do
thing <- tcLookupGlobal name
case thing of
ATyCon tc | Just cls <- tyConClass_maybe tc -> return cls
_ -> wrongThingErr "class" (AGlobal thing) name
tcLookupTyCon :: Name -> TcM TyCon
tcLookupTyCon name = do
thing <- tcLookupGlobal name
case thing of
ATyCon tc -> return tc
_ -> wrongThingErr "type constructor" (AGlobal thing) name
tcLookupAxiom :: Name -> TcM (CoAxiom Branched)
tcLookupAxiom name = do
thing <- tcLookupGlobal name
case thing of
ACoAxiom ax -> return ax
_ -> wrongThingErr "axiom" (AGlobal thing) name
tcLookupLocatedGlobalId :: Located Name -> TcM Id
tcLookupLocatedGlobalId = addLocM tcLookupId
tcLookupLocatedClass :: Located Name -> TcM Class
tcLookupLocatedClass = addLocM tcLookupClass
tcLookupLocatedTyCon :: Located Name -> TcM TyCon
tcLookupLocatedTyCon = addLocM tcLookupTyCon
tcLookupInstance :: Class -> [Type] -> TcM ClsInst
tcLookupInstance cls tys
= do { instEnv <- tcGetInstEnvs
; case lookupUniqueInstEnv instEnv cls tys of
Left err -> failWithTc $ ptext (sLit "Couldn't match instance:") <+> err
Right (inst, tys)
| uniqueTyVars tys -> return inst
| otherwise -> failWithTc errNotExact
}
where
errNotExact = ptext (sLit "Not an exact match (i.e., some variables get instantiated)")
uniqueTyVars tys = all isTyVarTy tys && hasNoDups (map extractTyVar tys)
where
extractTyVar (TyVarTy tv) = tv
extractTyVar _ = panic "TcEnv.tcLookupInstance: extractTyVar"
tcGetInstEnvs :: TcM InstEnvs
tcGetInstEnvs = do { eps <- getEps
; env <- getGblEnv
; return (InstEnvs { ie_global = eps_inst_env eps
, ie_local = tcg_inst_env env
, ie_visible = tcg_visible_orphan_mods env }) }
instance MonadThings (IOEnv (Env TcGblEnv TcLclEnv)) where
lookupThing = tcLookupGlobal
setGlobalTypeEnv :: TcGblEnv -> TypeEnv -> TcM TcGblEnv
setGlobalTypeEnv tcg_env new_type_env
= do {
writeMutVar (tcg_type_env_var tcg_env) new_type_env
; return (tcg_env { tcg_type_env = new_type_env }) }
tcExtendGlobalEnvImplicit :: [TyThing] -> TcM r -> TcM r
tcExtendGlobalEnvImplicit things 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 }
tcExtendGlobalEnv :: [TyThing] -> TcM r -> TcM r
tcExtendGlobalEnv things thing_inside
= do { env <- getGblEnv
; let env' = env { tcg_tcs = [tc | ATyCon tc <- things] ++ tcg_tcs env,
tcg_patsyns = [ps | AConLike (PatSynCon ps) <- things] ++ tcg_patsyns env }
; setGblEnv env' $
tcExtendGlobalEnvImplicit things thing_inside
}
tcExtendGlobalValEnv :: [Id] -> TcM a -> TcM a
tcExtendGlobalValEnv ids thing_inside
= tcExtendGlobalEnvImplicit [AnId id | id <- ids] thing_inside
tcExtendRecEnv :: [(Name,TyThing)] -> TcM r -> TcM r
tcExtendRecEnv gbl_stuff thing_inside
= 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 }
tcLookupLocated :: Located Name -> TcM TcTyThing
tcLookupLocated = addLocM tcLookup
tcLookupLcl_maybe :: Name -> TcM (Maybe TcTyThing)
tcLookupLcl_maybe name
= do { local_env <- getLclTypeEnv
; return (lookupNameEnv local_env name) }
tcLookup :: Name -> TcM TcTyThing
tcLookup name = do
local_env <- getLclTypeEnv
case lookupNameEnv local_env name of
Just thing -> return thing
Nothing -> AGlobal <$> tcLookupGlobal name
tcLookupTyVar :: Name -> TcM TcTyVar
tcLookupTyVar name
= do { thing <- tcLookup name
; case thing of
ATyVar _ tv -> return tv
_ -> pprPanic "tcLookupTyVar" (ppr name) }
tcLookupId :: Name -> TcM Id
tcLookupId name = do
thing <- tcLookup name
case thing of
ATcId { tct_id = id} -> return id
AGlobal (AnId id) -> return id
_ -> pprPanic "tcLookupId" (ppr name)
tcLookupLocalIds :: [Name] -> TcM [TcId]
tcLookupLocalIds ns
= do { env <- getLclEnv
; return (map (lookup (tcl_env env)) ns) }
where
lookup lenv name
= case lookupNameEnv lenv name of
Just (ATcId { tct_id = id }) -> id
_ -> pprPanic "tcLookupLocalIds" (ppr name)
getInLocalScope :: TcM (Name -> Bool)
getInLocalScope = do { lcl_env <- getLclTypeEnv
; return (`elemNameEnv` lcl_env) }
tcExtendKindEnv2 :: [(Name, TcTyThing)] -> TcM r -> TcM r
tcExtendKindEnv2 things thing_inside
= updLclEnv upd_env thing_inside
where
upd_env env = env { tcl_env = extendNameEnvList (tcl_env env) things }
tcExtendKindEnv :: [(Name, TcKind)] -> TcM r -> TcM r
tcExtendKindEnv name_kind_prs
= tcExtendKindEnv2 [(n, AThing k) | (n,k) <- name_kind_prs]
tcExtendTyVarEnv :: [TyVar] -> TcM r -> TcM r
tcExtendTyVarEnv tvs thing_inside
= tcExtendTyVarEnv2 [(tyVarName tv, tv) | tv <- tvs] thing_inside
tcExtendTyVarEnv2 :: [(Name,TcTyVar)] -> TcM r -> TcM r
tcExtendTyVarEnv2 binds thing_inside
= do { stage <- getStage
; tc_extend_local_env (NotTopLevel, thLevel stage)
[(name, ATyVar name tv) | (name, tv) <- binds] $
do { env <- getLclEnv
; let env' = env { tcl_tidy = add_tidy_tvs (tcl_tidy env) }
; setLclEnv env' thing_inside }}
where
add_tidy_tvs env = foldl add env binds
add :: TidyEnv -> (Name, TcTyVar) -> TidyEnv
add (env,subst) (name, tyvar)
= case tidyOccName env (nameOccName name) of
(env', occ') -> (env', extendVarEnv subst tyvar tyvar')
where
tyvar' = setTyVarName tyvar name'
name' = tidyNameOcc name occ'
getScopedTyVarBinds :: TcM [(Name, TcTyVar)]
getScopedTyVarBinds
= do { lcl_env <- getLclEnv
; return [(name, tv) | ATyVar name tv <- nameEnvElts (tcl_env lcl_env)] }
tcExtendGhciIdEnv :: [TyThing] -> TcM a -> TcM a
tcExtendGhciIdEnv ids thing_inside
= do { lcl_env <- tcExtendLocalTypeEnv tc_ty_things emptyVarSet
; setLclEnv lcl_env thing_inside }
where
tc_ty_things = [ (name, ATcId { tct_id = id
, tct_closed = is_top id })
| AnId id <- ids
, let name = idName id
, isInternalName name ]
is_top id | isEmptyVarSet (tyVarsOfType (idType id)) = TopLevel
| otherwise = NotTopLevel
tcExtendLetEnv :: TopLevelFlag -> TopLevelFlag -> [TcId] -> TcM a -> TcM a
tcExtendLetEnv top_lvl closed ids thing_inside
= do { stage <- getStage
; tc_extend_local_env (top_lvl, thLevel stage)
[ (idName id, ATcId { tct_id = id
, tct_closed = closed })
| id <- ids] $
tcExtendIdBndrs [TcIdBndr id top_lvl | id <- ids] thing_inside }
tcExtendIdEnv :: [TcId] -> TcM a -> TcM a
tcExtendIdEnv ids thing_inside
= tcExtendIdEnv2 [(idName id, id) | id <- ids] $
tcExtendIdBndrs [TcIdBndr id NotTopLevel | id <- ids]
thing_inside
tcExtendIdEnv1 :: Name -> TcId -> TcM a -> TcM a
tcExtendIdEnv1 name id thing_inside
= tcExtendIdEnv2 [(name,id)] $
tcExtendIdBndrs [TcIdBndr id NotTopLevel]
thing_inside
tcExtendIdEnv2 :: [(Name,TcId)] -> TcM a -> TcM a
tcExtendIdEnv2 names_w_ids thing_inside
= tcExtendIdEnv3 names_w_ids emptyVarSet thing_inside
tcExtendIdEnv3 :: [(Name,TcId)] -> TyVarSet -> TcM a -> TcM a
tcExtendIdEnv3 names_w_ids not_actually_free thing_inside
= do { stage <- getStage
; tc_extend_local_env2 (NotTopLevel, thLevel stage)
[ (name, ATcId { tct_id = id
, tct_closed = NotTopLevel })
| (name,id) <- names_w_ids] not_actually_free $
thing_inside }
tcExtendIdBndrs :: [TcIdBinder] -> TcM a -> TcM a
tcExtendIdBndrs bndrs = updLclEnv (\env -> env { tcl_bndrs = bndrs ++ tcl_bndrs env })
tc_extend_local_env :: (TopLevelFlag, ThLevel) -> [(Name, TcTyThing)] -> TcM a -> TcM a
tc_extend_local_env thlvl extra_env thing_inside =
tc_extend_local_env2 thlvl extra_env emptyVarSet thing_inside
tc_extend_local_env2 :: (TopLevelFlag, ThLevel) -> [(Name, TcTyThing)]
-> TyVarSet -> TcM a -> TcM a
tc_extend_local_env2 thlvl extra_env not_actually_free thing_inside
= do { traceTc "env2" (ppr extra_env)
; env1 <- tcExtendLocalTypeEnv extra_env not_actually_free
; let env2 = extend_local_env thlvl extra_env env1
; setLclEnv env2 thing_inside }
where
extend_local_env :: (TopLevelFlag, ThLevel) -> [(Name, TcTyThing)] -> TcLclEnv -> TcLclEnv
extend_local_env thlvl pairs env@(TcLclEnv { tcl_rdr = rdr_env
, tcl_th_bndrs = th_bndrs })
= env { tcl_rdr = extendLocalRdrEnvList rdr_env
[ n | (n, _) <- pairs, isInternalName n ]
, tcl_th_bndrs = extendNameEnvList th_bndrs
[(n, thlvl) | (n, ATcId {}) <- pairs] }
tcExtendLocalTypeEnv :: [(Name, TcTyThing)] -> TyVarSet -> TcM TcLclEnv
tcExtendLocalTypeEnv tc_ty_things not_actually_free
| isEmptyVarSet extra_tvs
= do { lcl_env@(TcLclEnv { tcl_env = lcl_type_env }) <- getLclEnv
; return (lcl_env { tcl_env = extendNameEnvList lcl_type_env tc_ty_things } ) }
| otherwise
= do { lcl_env@(TcLclEnv { tcl_env = lcl_type_env }) <- getLclEnv
; global_tvs <- readMutVar (tcl_tyvars lcl_env)
; new_g_var <- newMutVar (global_tvs `unionVarSet` extra_tvs)
; return (lcl_env { tcl_tyvars = new_g_var
, tcl_env = extendNameEnvList lcl_type_env tc_ty_things } ) }
where
extra_tvs = foldr get_tvs emptyVarSet tc_ty_things `minusVarSet` not_actually_free
get_tvs (_, ATcId { tct_id = id, tct_closed = closed }) tvs
= case closed of
TopLevel -> ASSERT2( isEmptyVarSet id_tvs, ppr id $$ ppr (idType id) )
tvs
NotTopLevel -> tvs `unionVarSet` id_tvs
where id_tvs = tyVarsOfType (idType id)
get_tvs (_, ATyVar _ tv) tvs
= tvs `unionVarSet` tyVarsOfType (tyVarKind tv) `extendVarSet` tv
get_tvs (_, AThing k) tvs = tvs `unionVarSet` tyVarsOfType k
get_tvs (_, AGlobal {}) tvs = tvs
get_tvs (_, APromotionErr {}) tvs = tvs
zapLclTypeEnv :: TcM a -> TcM a
zapLclTypeEnv thing_inside
= do { tvs_var <- newTcRef emptyVarSet
; let upd env = env { tcl_env = emptyNameEnv
, tcl_rdr = emptyLocalRdrEnv
, tcl_tyvars = tvs_var }
; updLclEnv upd thing_inside }
tcExtendRules :: [LRuleDecl Id] -> TcM a -> TcM a
tcExtendRules lcl_rules thing_inside
= do { env <- getGblEnv
; let
env' = env { tcg_rules = lcl_rules ++ tcg_rules env }
; setGblEnv env' thing_inside }
checkWellStaged :: SDoc
-> ThLevel
-> ThLevel
-> TcM ()
checkWellStaged pp_thing bind_lvl use_lvl
| use_lvl >= bind_lvl
= return ()
| bind_lvl == outerLevel
= stageRestrictionError pp_thing
| otherwise
= 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]
stageRestrictionError :: SDoc -> TcM a
stageRestrictionError pp_thing
= failWithTc $
sep [ ptext (sLit "GHC stage restriction:")
, nest 2 (vcat [ pp_thing <+> ptext (sLit "is used in a top-level splice or annotation,")
, ptext (sLit "and must be imported, not defined locally")])]
topIdLvl :: Id -> ThLevel
topIdLvl id | isLocalId id = outerLevel
| otherwise = impLevel
tcMetaTy :: Name -> TcM Type
tcMetaTy tc_name = do
t <- tcLookupTyCon tc_name
return (mkTyConApp t [])
isBrackStage :: ThStage -> Bool
isBrackStage (Brack {}) = True
isBrackStage _other = False
tcGetDefaultTys :: TcM ([Type],
(Bool,
Bool))
tcGetDefaultTys
= do { dflags <- getDynFlags
; let ovl_strings = xopt Opt_OverloadedStrings dflags
extended_defaults = xopt Opt_ExtendedDefaultRules dflags
flags = (ovl_strings, extended_defaults)
; mb_defaults <- getDeclaredDefaultTys
; case mb_defaults of {
Just tys -> return (tys, flags) ;
Nothing -> do
{ integer_ty <- tcMetaTy integerTyConName
; checkWiredInTyCon doubleTyCon
; string_ty <- tcMetaTy stringTyConName
; let deflt_tys = opt_deflt extended_defaults unitTy
++ [integer_ty, doubleTy]
++ opt_deflt ovl_strings string_ty
; return (deflt_tys, flags) } } }
where
opt_deflt True ty = [ty]
opt_deflt False _ = []
data InstInfo a
= InstInfo {
iSpec :: ClsInst,
iBinds :: InstBindings a
}
iDFunId :: InstInfo a -> DFunId
iDFunId info = instanceDFunId (iSpec info)
data InstBindings a
= InstBindings
{ ib_tyvars :: [Name]
, ib_binds :: (LHsBinds a)
, ib_pragmas :: [LSig a]
, ib_extensions :: [ExtensionFlag]
, ib_derived :: Bool
}
instance OutputableBndr a => Outputable (InstInfo a) where
ppr = pprInstInfoDetails
pprInstInfoDetails :: OutputableBndr a => InstInfo a -> SDoc
pprInstInfoDetails info
= hang (pprInstanceHdr (iSpec info) <+> ptext (sLit "where"))
2 (details (iBinds info))
where
details (InstBindings { ib_binds = b }) = pprLHsBinds b
simpleInstInfoClsTy :: InstInfo a -> (Class, Type)
simpleInstInfoClsTy info = case instanceHead (iSpec info) of
(_, cls, [ty]) -> (cls, ty)
_ -> panic "simpleInstInfoClsTy"
simpleInstInfoTy :: InstInfo a -> Type
simpleInstInfoTy info = snd (simpleInstInfoClsTy info)
simpleInstInfoTyCon :: InstInfo a -> TyCon
simpleInstInfoTyCon inst = tcTyConAppTyCon (simpleInstInfoTy inst)
newDFunName :: Class -> [Type] -> SrcSpan -> TcM Name
newDFunName clas tys loc
= do { is_boot <- tcIsHsBootOrSig
; mod <- getModule
; let info_string = occNameString (getOccName clas) ++
concatMap (occNameString.getDFunTyKey) tys
; dfun_occ <- chooseUniqueOccTc (mkDFunOcc info_string is_boot)
; newGlobalBinder mod dfun_occ loc }
newFamInstTyConName :: Located Name -> [Type] -> TcM Name
newFamInstTyConName (L loc name) tys = mk_fam_inst_name id loc name [tys]
newFamInstAxiomName :: SrcSpan -> Name -> [CoAxBranch] -> TcM Name
newFamInstAxiomName loc name branches
= mk_fam_inst_name mkInstTyCoOcc loc name (map coAxBranchLHS branches)
mk_fam_inst_name :: (OccName -> OccName) -> SrcSpan -> Name -> [[Type]] -> TcM Name
mk_fam_inst_name adaptOcc loc tc_name tyss
= do { mod <- getModule
; let info_string = occNameString (getOccName tc_name) ++
intercalate "|" ty_strings
; occ <- chooseUniqueOccTc (mkInstTyTcOcc info_string)
; newGlobalBinder mod (adaptOcc occ) loc }
where
ty_strings = map (concatMap (occNameString . getDFunTyKey)) tyss
mkStableIdFromString :: String -> Type -> SrcSpan -> (OccName -> OccName) -> TcM TcId
mkStableIdFromString str sig_ty loc occ_wrapper = do
uniq <- newUnique
mod <- getModule
name <- mkWrapperName "stable" str
let occ = mkVarOccFS name :: OccName
gnm = mkExternalName uniq mod (occ_wrapper occ) loc :: Name
id = mkExportedLocalId VanillaId gnm sig_ty :: Id
return id
mkStableIdFromName :: Name -> Type -> SrcSpan -> (OccName -> OccName) -> TcM TcId
mkStableIdFromName nm = mkStableIdFromString (getOccString nm)
mkWrapperName :: (MonadIO m, HasDynFlags m, HasModule m)
=> String -> String -> m FastString
mkWrapperName what nameBase
= do dflags <- getDynFlags
thisMod <- getModule
let
wrapperRef = nextWrapperNum dflags
pkg = packageKeyString (modulePackageKey thisMod)
mod = moduleNameString (moduleName thisMod)
wrapperNum <- liftIO $ atomicModifyIORef wrapperRef $ \mod_env ->
let num = lookupWithDefaultModuleEnv mod_env 0 thisMod
mod_env' = extendModuleEnv mod_env thisMod (num+1)
in (mod_env', num)
let components = [what, show wrapperNum, pkg, mod, nameBase]
return $ mkFastString $ zEncodeString $ intercalate ":" components
pprBinders :: [Name] -> SDoc
pprBinders [bndr] = quotes (ppr bndr)
pprBinders bndrs = pprWithCommas ppr bndrs
notFound :: Name -> TcM TyThing
notFound name
= do { lcl_env <- getLclEnv
; let stage = tcl_th_ctxt lcl_env
; case stage of
Splice {} -> stageRestrictionError (quotes (ppr name))
_ -> 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 "tcl_env of environment:") <+> ppr (tcl_env lcl_env)]
}
wrongThingErr :: String -> TcTyThing -> Name -> TcM a
wrongThingErr expected thing name
= failWithTc (pprTcTyThingCategory thing <+> quotes (ppr name) <+>
ptext (sLit "used as a") <+> text expected)