#include "HsVersions.h"
import HsSyn ( TyClDecl(..), HsConDetails(..), HsTyVarBndr(..),
- ConDecl(..), Sig(..), BangType(..), HsBang(..),
- tyClDeclTyVars, getBangType, getBangStrictness
+ ConDecl(..), Sig(..), , NewOrData(..),
+ tyClDeclTyVars, isSynDecl, LConDecl,
+ LTyClDecl, tcdName, LHsTyVarBndr, LHsContext
)
-import RnHsSyn ( RenamedTyClDecl, RenamedConDecl )
-import BasicTypes ( RecFlag(..), NewOrData(..), StrictnessMark(..) )
+import HsTypes ( HsBang(..), getBangStrictness )
+import BasicTypes ( RecFlag(..), StrictnessMark(..) )
import HscTypes ( implicitTyThings )
-import BuildTyCl ( buildClass, buildAlgTyCon, buildSynTyCon, buildDataCon )
+import BuildTyCl ( buildClass, buildAlgTyCon, buildSynTyCon, buildDataCon,
+ mkDataTyConRhs, mkNewTyConRhs )
import TcRnMonad
import TcEnv ( TcTyThing(..), TyThing(..),
- tcLookup, tcLookupGlobal, tcExtendGlobalEnv,
+ tcLookupLocated, tcLookupLocatedGlobal,
+ tcExtendGlobalEnv, tcExtendKindEnv,
tcExtendRecEnv, tcLookupTyVar )
-import TcTyDecls ( calcTyConArgVrcs, calcRecFlags, calcCycleErrs )
+import TcTyDecls ( calcTyConArgVrcs, calcRecFlags, calcClassCycles, calcSynCycles )
import TcClassDcl ( tcClassSigs, tcAddDeclCtxt )
-import TcHsType ( kcHsTyVars, kcHsLiftedSigType, kcHsSigType, kcCheckHsType,
- kcHsContext, tcTyVarBndrs, tcHsKindedType, tcHsKindedContext )
+import TcHsType ( kcHsTyVars, kcHsLiftedSigType, kcHsType,
+ kcHsContext, tcTyVarBndrs, tcHsKindedType, tcHsKindedContext,
+ kcHsSigType, tcHsBangType, tcLHsConSig )
import TcMType ( newKindVar, checkValidTheta, checkValidType, checkFreeness,
- UserTypeCtxt(..), SourceTyCtxt(..), pprUserTypeCtxt )
+ UserTypeCtxt(..), SourceTyCtxt(..) )
import TcUnify ( unifyKind )
-import TcType ( TcKind, ThetaType, TcType,
- mkArrowKind, liftedTypeKind,
+import TcType ( TcKind, ThetaType, TcType, tyVarsOfType,
+ mkArrowKind, liftedTypeKind, mkTyVarTys, tcEqTypes,
tcSplitSigmaTy, tcEqType )
-import Type ( splitTyConApp_maybe )
-import PprType ( pprThetaArrow, pprParendType )
-import FieldLabel ( fieldLabelName, fieldLabelType )
+import Type ( splitTyConApp_maybe, pprThetaArrow, pprParendType )
import Generics ( validGenericMethodType, canDoGenerics )
-import Class ( Class, className, classTyCon, DefMeth(..), classBigSig )
-import TyCon ( TyCon, ArgVrcs, DataConDetails(..),
+import Class ( Class, className, classTyCon, DefMeth(..), classBigSig, classTyVars )
+import TyCon ( TyCon, ArgVrcs,
tyConDataCons, mkForeignTyCon, isProductTyCon, isRecursiveTyCon,
- tyConTheta, getSynTyConDefn, tyConDataCons, isSynTyCon, tyConName )
-import DataCon ( DataCon, dataConWrapId, dataConName, dataConSig, dataConFieldLabels )
+ tyConStupidTheta, getSynTyConDefn, tyConDataCons, isSynTyCon, tyConName )
+import DataCon ( DataCon, dataConWrapId, dataConName, dataConSig,
+ dataConFieldLabels, dataConOrigArgTys, dataConTyCon )
+import Type ( zipTopTvSubst, substTys )
import Var ( TyVar, idType, idName )
-import Name ( Name, getSrcLoc )
+import VarSet ( elemVarSet )
+import Name ( Name )
import Outputable
-import Util ( zipLazy, isSingleton, notNull )
+import Util ( zipLazy, isSingleton, notNull, sortLe )
+import List ( partition )
+import SrcLoc ( Located(..), unLoc, getLoc )
import ListSetOps ( equivClasses )
+import Digraph ( SCC(..) )
import CmdLineOpts ( DynFlag( Opt_GlasgowExts, Opt_Generics, Opt_UnboxStrictFields ) )
\end{code}
@TyThing@s. @rec_vrcs@ is a finite map from @Name@s to @ArgVrcs@s.
\begin{code}
-tcTyAndClassDecls :: [RenamedTyClDecl]
+tcTyAndClassDecls :: [Name] -> [LTyClDecl Name]
-> TcM TcGblEnv -- Input env extended by types and classes
-- and their implicit Ids,DataCons
-tcTyAndClassDecls decls
+tcTyAndClassDecls boot_names decls
= do { -- First check for cyclic type synonysm or classes
-- See notes with checkCycleErrs
checkCycleErrs decls
-
- ; tyclss <- fixM (\ rec_tyclss ->
- do { lcl_things <- mappM getInitialKind decls
- -- Extend the local env with kinds, and
- -- the global env with the knot-tied results
- ; let { gbl_things = mkGlobalThings decls rec_tyclss }
- ; tcExtendRecEnv gbl_things lcl_things $ do
-
- -- The local type environment is populated with
- -- {"T" -> ARecTyCon k, ...}
- -- and the global type envt with
- -- {"T" -> ATyCon T, ...}
- -- where k is T's (unzonked) kind
- -- T is the loop-tied TyCon itself
- -- We must populate the environment with the loop-tied T's right
- -- away, because the kind checker may "fault in" some type
- -- constructors that recursively mention T
-
- -- Kind-check the declarations, returning kind-annotated decls
- { kc_decls <- mappM kcTyClDecl decls
-
- -- Calculate variances and rec-flag
- ; let { calc_vrcs = calcTyConArgVrcs rec_tyclss
- ; calc_rec = calcRecFlags rec_tyclss }
-
- ; mappM (tcTyClDecl calc_vrcs calc_rec) kc_decls
- }})
+ ; mod <- getModule
+ ; traceTc (text "tcTyAndCl" <+> ppr mod <+> ppr boot_names)
+ ; (syn_tycons, alg_tyclss) <- fixM (\ ~(rec_syn_tycons, rec_alg_tyclss) ->
+ do { let { -- Calculate variances and rec-flag
+ ; (syn_decls, alg_decls) = partition (isSynDecl . unLoc) decls }
+
+ -- Extend the global env with the knot-tied results
+ -- for data types and classes
+ --
+ -- We must populate the environment with the loop-tied T's right
+ -- away, because the kind checker may "fault in" some type
+ -- constructors that recursively mention T
+ ; let { gbl_things = mkGlobalThings alg_decls rec_alg_tyclss }
+ ; tcExtendRecEnv gbl_things $ do
+
+ -- Kind-check the declarations
+ { (kc_syn_decls, kc_alg_decls) <- kcTyClDecls syn_decls alg_decls
+
+ ; let { calc_vrcs = calcTyConArgVrcs (rec_syn_tycons ++ rec_alg_tyclss)
+ ; calc_rec = calcRecFlags boot_names rec_alg_tyclss
+ ; tc_decl = addLocM (tcTyClDecl calc_vrcs calc_rec) }
+ -- Type-check the type synonyms, and extend the envt
+ ; syn_tycons <- tcSynDecls calc_vrcs kc_syn_decls
+ ; tcExtendGlobalEnv syn_tycons $ do
+
+ -- Type-check the data types and classes
+ { alg_tyclss <- mappM tc_decl kc_alg_decls
+ ; return (syn_tycons, alg_tyclss)
+ }}})
-- Finished with knot-tying now
-- Extend the environment with the finished things
- ; tcExtendGlobalEnv tyclss $ do
+ ; tcExtendGlobalEnv (syn_tycons ++ alg_tyclss) $ do
-- Perform the validity check
{ traceTc (text "ready for validity check")
- ; mappM_ checkValidTyCl decls
+ ; mappM_ (addLocM checkValidTyCl) decls
; traceTc (text "done")
-- Add the implicit things;
-- we want them in the environment because
-- they may be mentioned in interface files
- ; let { implicit_things = concatMap implicitTyThings tyclss }
- ; traceTc ((text "Adding" <+> ppr tyclss) $$ (text "and" <+> ppr implicit_things))
+ ; let { implicit_things = concatMap implicitTyThings alg_tyclss }
+ ; traceTc ((text "Adding" <+> ppr alg_tyclss) $$ (text "and" <+> ppr implicit_things))
; tcExtendGlobalEnv implicit_things getGblEnv
}}
-mkGlobalThings :: [RenamedTyClDecl] -- The decls
+mkGlobalThings :: [LTyClDecl Name] -- The decls
-> [TyThing] -- Knot-tied, in 1-1 correspondence with the decls
-> [(Name,TyThing)]
-- Driven by the Decls, and treating the TyThings lazily
mkGlobalThings decls things
= map mk_thing (decls `zipLazy` things)
where
- mk_thing (ClassDecl {tcdName = name}, ~(AClass cl)) = (name, AClass cl)
- mk_thing (decl, ~(ATyCon tc)) = (tcdName decl, ATyCon tc)
+ mk_thing (L _ (ClassDecl {tcdLName = L _ name}), ~(AClass cl))
+ = (name, AClass cl)
+ mk_thing (L _ decl, ~(ATyCon tc))
+ = (tcdName decl, ATyCon tc)
\end{code}
depends on *all the uses of class D*. For example, the use of
Monad c in bop's type signature means that D must have kind Type->Type.
-\begin{code}
-------------------------------------------------------------------------
-getInitialKind :: TyClDecl Name -> TcM (Name, TcTyThing)
-
--- Note the lazy pattern match on the ATyCon etc
--- Exactly the same reason as the zipLay above
-
-getInitialKind (TyData {tcdName = name})
- = newKindVar `thenM` \ kind ->
- returnM (name, ARecTyCon kind)
-
-getInitialKind (TySynonym {tcdName = name})
- = newKindVar `thenM` \ kind ->
- returnM (name, ARecTyCon kind)
-
-getInitialKind (ClassDecl {tcdName = name})
- = newKindVar `thenM` \ kind ->
- returnM (name, ARecClass kind)
+However type synonyms work differently. They can have kinds which don't
+just involve (->) and *:
+ type R = Int# -- Kind #
+ type S a = Array# a -- Kind * -> #
+ type T a b = (# a,b #) -- Kind * -> * -> (# a,b #)
+So we must infer their kinds from their right-hand sides *first* and then
+use them, whereas for the mutually recursive data types D we bring into
+scope kind bindings D -> k, where k is a kind variable, and do inference.
+\begin{code}
+kcTyClDecls syn_decls alg_decls
+ = do { -- First extend the kind env with each data
+ -- type and class, mapping them to a type variable
+ alg_kinds <- mappM getInitialKind alg_decls
+ ; tcExtendKindEnv alg_kinds $ do
+
+ -- Now kind-check the type synonyms, in dependency order
+ -- We do these differently to data type and classes,
+ -- because a type synonym can be an unboxed type
+ -- type Foo = Int#
+ -- and a kind variable can't unify with UnboxedTypeKind
+ -- So we infer their kinds in dependency order
+ { (kc_syn_decls, syn_kinds) <- kcSynDecls (calcSynCycles syn_decls)
+ ; tcExtendKindEnv syn_kinds $ do
+
+ -- Now kind-check the data type and class declarations,
+ -- returning kind-annotated decls
+ { kc_alg_decls <- mappM (wrapLocM kcTyClDecl) alg_decls
+
+ ; return (kc_syn_decls, kc_alg_decls) }}}
------------------------------------------------------------------------
-kcTyClDecl :: RenamedTyClDecl -> TcM RenamedTyClDecl
+getInitialKind :: LTyClDecl Name -> TcM (Name, TcKind)
+
+getInitialKind decl
+ = newKindVar `thenM` \ kind ->
+ returnM (unLoc (tcdLName (unLoc decl)), kind)
+
+----------------
+kcSynDecls :: [SCC (LTyClDecl Name)]
+ -> TcM ([LTyClDecl Name], -- Kind-annotated decls
+ [(Name,TcKind)]) -- Kind bindings
+kcSynDecls []
+ = return ([], [])
+kcSynDecls (group : groups)
+ = do { (decl, nk) <- kcSynDecl group
+ ; (decls, nks) <- tcExtendKindEnv [nk] (kcSynDecls groups)
+ ; return (decl:decls, nk:nks) }
+
+----------------
+kcSynDecl :: SCC (LTyClDecl Name)
+ -> TcM (LTyClDecl Name, -- Kind-annotated decls
+ (Name,TcKind)) -- Kind bindings
+kcSynDecl (AcyclicSCC ldecl@(L loc decl))
+ = tcAddDeclCtxt decl $
+ kcHsTyVars (tcdTyVars decl) (\ k_tvs ->
+ do { traceTc (text "kcd1" <+> ppr (unLoc (tcdLName decl)) <+> brackets (ppr (tcdTyVars decl))
+ <+> brackets (ppr k_tvs))
+ ; (k_rhs, rhs_kind) <- kcHsType (tcdSynRhs decl)
+ ; traceTc (text "kcd2" <+> ppr (unLoc (tcdLName decl)))
+ ; let tc_kind = foldr (mkArrowKind . kindedTyVarKind) rhs_kind k_tvs
+ ; return (L loc (decl { tcdTyVars = k_tvs, tcdSynRhs = k_rhs }),
+ (unLoc (tcdLName decl), tc_kind)) })
+
+kcSynDecl (CyclicSCC decls)
+ = do { recSynErr decls; failM } -- Fail here to avoid error cascade
+ -- of out-of-scope tycons
-kcTyClDecl decl@(TySynonym {tcdSynRhs = rhs})
- = do { res_kind <- newKindVar
- ; kcTyClDeclBody decl res_kind $ \ tvs' ->
- do { rhs' <- kcCheckHsType rhs res_kind
- ; return (decl {tcdTyVars = tvs', tcdSynRhs = rhs'}) } }
+------------------------------------------------------------------------
+kcTyClDecl :: TyClDecl Name -> TcM (TyClDecl Name)
+ -- Not used for type synonyms (see kcSynDecl)
kcTyClDecl decl@(TyData {tcdND = new_or_data, tcdCtxt = ctxt, tcdCons = cons})
- = kcTyClDeclBody decl liftedTypeKind $ \ tvs' ->
+ = kcTyClDeclBody decl $ \ tvs' ->
do { ctxt' <- kcHsContext ctxt
- ; cons' <- mappM kc_con_decl cons
+ ; cons' <- mappM (wrapLocM kc_con_decl) cons
; return (decl {tcdTyVars = tvs', tcdCtxt = ctxt', tcdCons = cons'}) }
where
- kc_con_decl (ConDecl name ex_tvs ex_ctxt details loc)
+ kc_con_decl (ConDecl name ex_tvs ex_ctxt details)
= kcHsTyVars ex_tvs $ \ ex_tvs' ->
do { ex_ctxt' <- kcHsContext ex_ctxt
; details' <- kc_con_details details
- ; return (ConDecl name ex_tvs' ex_ctxt' details' loc)}
+ ; return (ConDecl name ex_tvs' ex_ctxt' details')}
+ kc_con_decl (GadtDecl name ty)
+ = do { ty' <- kcHsSigType ty
+ ; return (GadtDecl name ty') }
kc_con_details (PrefixCon btys)
- = do { btys' <- mappM kc_arg_ty btys ; return (PrefixCon btys') }
+ = do { btys' <- mappM kc_larg_ty btys ; return (PrefixCon btys') }
kc_con_details (InfixCon bty1 bty2)
- = do { bty1' <- kc_arg_ty bty1; bty2' <- kc_arg_ty bty2; return (InfixCon bty1' bty2') }
+ = do { bty1' <- kc_larg_ty bty1; bty2' <- kc_larg_ty bty2; return (InfixCon bty1' bty2') }
kc_con_details (RecCon fields)
= do { fields' <- mappM kc_field fields; return (RecCon fields') }
- kc_field (fld, bty) = do { bty' <- kc_arg_ty bty ; return (fld, bty') }
+ kc_field (fld, bty) = do { bty' <- kc_larg_ty bty ; return (fld, bty') }
- kc_arg_ty (BangType str ty) = do { ty' <- kc_arg_ty_body ty; return (BangType str ty') }
- kc_arg_ty_body = case new_or_data of
- DataType -> kcHsSigType
- NewType -> kcHsLiftedSigType
- -- Can't allow an unlifted type for newtypes, because we're effectively
- -- going to remove the constructor while coercing it to a lifted type.
+ kc_larg_ty bty = case new_or_data of
+ DataType -> kcHsSigType bty
+ NewType -> kcHsLiftedSigType bty
+ -- Can't allow an unlifted type for newtypes, because we're effectively
+ -- going to remove the constructor while coercing it to a lifted type.
+ -- And newtypes can't be bang'd
kcTyClDecl decl@(ClassDecl {tcdCtxt = ctxt, tcdSigs = sigs})
- = kcTyClDeclBody decl liftedTypeKind $ \ tvs' ->
+ = kcTyClDeclBody decl $ \ tvs' ->
do { ctxt' <- kcHsContext ctxt
- ; sigs' <- mappM kc_sig sigs
+ ; sigs' <- mappM (wrapLocM kc_sig) sigs
; return (decl {tcdTyVars = tvs', tcdCtxt = ctxt', tcdSigs = sigs'}) }
where
- kc_sig (Sig nm op_ty loc) = do { op_ty' <- kcHsLiftedSigType op_ty
- ; return (Sig nm op_ty' loc) }
+ kc_sig (Sig nm op_ty) = do { op_ty' <- kcHsLiftedSigType op_ty
+ ; return (Sig nm op_ty') }
kc_sig other_sig = return other_sig
-kcTyClDecl decl@(ForeignType {})
+kcTyClDecl decl@(ForeignType {})
= return decl
-kcTyClDeclBody :: RenamedTyClDecl -> TcKind
- -> ([HsTyVarBndr Name] -> TcM a)
+kcTyClDeclBody :: TyClDecl Name
+ -> ([LHsTyVarBndr Name] -> TcM a)
-> TcM a
-- Extend the env with bindings for the tyvars, taken from
-- the kind of the tycon/class. Give it to the thing inside, and
-- check the result kind matches
-kcTyClDeclBody decl res_kind thing_inside
+kcTyClDeclBody decl thing_inside
= tcAddDeclCtxt decl $
kcHsTyVars (tyClDeclTyVars decl) $ \ kinded_tvs ->
- do { tc_ty_thing <- tcLookup (tcdName decl)
- ; let { tc_kind = case tc_ty_thing of
- ARecClass k -> k
- ARecTyCon k -> k
- }
+ do { tc_ty_thing <- tcLookupLocated (tcdLName decl)
+ ; let tc_kind = case tc_ty_thing of { AThing k -> k }
; unifyKind tc_kind (foldr (mkArrowKind . kindedTyVarKind)
- res_kind kinded_tvs)
+ (result_kind decl)
+ kinded_tvs)
; thing_inside kinded_tvs }
+ where
+ result_kind (TyData { tcdKindSig = Just kind }) = kind
+ result_kind other = liftedTypeKind
+ -- On GADT-style declarations we allow a kind signature
+ -- data T :: *->* where { ... }
-kindedTyVarKind (KindedTyVar _ k) = k
+kindedTyVarKind (L _ (KindedTyVar _ k)) = k
\end{code}
%************************************************************************
\begin{code}
+tcSynDecls :: (Name -> ArgVrcs) -> [LTyClDecl Name] -> TcM [TyThing]
+tcSynDecls calc_vrcs [] = return []
+tcSynDecls calc_vrcs (decl : decls)
+ = do { syn_tc <- addLocM (tcSynDecl calc_vrcs) decl
+ ; syn_tcs <- tcExtendGlobalEnv [syn_tc] (tcSynDecls calc_vrcs decls)
+ ; return (syn_tc : syn_tcs) }
+
+tcSynDecl calc_vrcs
+ (TySynonym {tcdLName = L _ tc_name, tcdTyVars = tvs, tcdSynRhs = rhs_ty})
+ = tcTyVarBndrs tvs $ \ tvs' -> do
+ { traceTc (text "tcd1" <+> ppr tc_name)
+ ; rhs_ty' <- tcHsKindedType rhs_ty
+ ; return (ATyCon (buildSynTyCon tc_name tvs' rhs_ty' (calc_vrcs tc_name))) }
+
+--------------------
tcTyClDecl :: (Name -> ArgVrcs) -> (Name -> RecFlag)
- -> RenamedTyClDecl -> TcM TyThing
+ -> TyClDecl Name -> TcM TyThing
tcTyClDecl calc_vrcs calc_isrec decl
= tcAddDeclCtxt decl (tcTyClDecl1 calc_vrcs calc_isrec decl)
tcTyClDecl1 calc_vrcs calc_isrec
- (TySynonym {tcdName = tc_name, tcdTyVars = tvs, tcdSynRhs = rhs_ty})
- = tcTyVarBndrs tvs $ \ tvs' -> do
- { rhs_ty' <- tcHsKindedType rhs_ty
- ; return (ATyCon (buildSynTyCon tc_name tvs' rhs_ty' arg_vrcs)) }
- where
- arg_vrcs = calc_vrcs tc_name
-
-tcTyClDecl1 calc_vrcs calc_isrec
- (TyData {tcdND = new_or_data, tcdCtxt = ctxt, tcdTyVars = tvs,
- tcdName = tc_name, tcdCons = cons})
+ (TyData {tcdND = new_or_data, tcdCtxt = ctxt, tcdTyVars = tvs,
+ tcdLName = L _ tc_name, tcdCons = cons})
= tcTyVarBndrs tvs $ \ tvs' -> do
- { ctxt' <- tcHsKindedContext ctxt
+ { stupid_theta <- tcStupidTheta ctxt cons
; want_generic <- doptM Opt_Generics
; tycon <- fixM (\ tycon -> do
- { cons' <- mappM (tcConDecl new_or_data tycon tvs' ctxt') cons
- ; buildAlgTyCon new_or_data tc_name tvs' ctxt'
- (DataCons cons') arg_vrcs is_rec
- (want_generic && canDoGenerics cons')
+ { unbox_strict <- doptM Opt_UnboxStrictFields
+ ; gla_exts <- doptM Opt_GlasgowExts
+ ; checkTc (gla_exts || h98_syntax) (badGadtDecl tc_name)
+
+ ; data_cons <- mappM (addLocM (tcConDecl unbox_strict new_or_data tycon tvs')) cons
+ ; let tc_rhs = case new_or_data of
+ DataType -> mkDataTyConRhs stupid_theta data_cons
+ NewType -> ASSERT( isSingleton data_cons )
+ mkNewTyConRhs tycon (head data_cons)
+ ; buildAlgTyCon tc_name tvs' tc_rhs arg_vrcs is_rec
+ (want_generic && canDoGenerics data_cons)
})
; return (ATyCon tycon)
}
where
arg_vrcs = calc_vrcs tc_name
is_rec = calc_isrec tc_name
+ h98_syntax = case cons of -- All constructors have same shape
+ L _ (GadtDecl {}) : _ -> False
+ other -> True
tcTyClDecl1 calc_vrcs calc_isrec
- (ClassDecl {tcdName = class_name, tcdTyVars = tvs,
- tcdCtxt = ctxt, tcdMeths = meths,
- tcdFDs = fundeps, tcdSigs = sigs} )
+ (ClassDecl {tcdLName = L _ class_name, tcdTyVars = tvs,
+ tcdCtxt = ctxt, tcdMeths = meths,
+ tcdFDs = fundeps, tcdSigs = sigs} )
= tcTyVarBndrs tvs $ \ tvs' -> do
{ ctxt' <- tcHsKindedContext ctxt
- ; fds' <- mappM tc_fundep fundeps
+ ; fds' <- mappM (addLocM tc_fundep) fundeps
; sig_stuff <- tcClassSigs class_name sigs meths
; clas <- fixM (\ clas ->
let -- This little knot is just so we can get
tcTyClDecl1 calc_vrcs calc_isrec
- (ForeignType {tcdName = tc_name, tcdExtName = tc_ext_name})
+ (ForeignType {tcdLName = L _ tc_name, tcdExtName = tc_ext_name})
= returnM (ATyCon (mkForeignTyCon tc_name tc_ext_name liftedTypeKind 0 []))
-----------------------------------
-tcConDecl :: NewOrData -> TyCon -> [TyVar] -> ThetaType
- -> RenamedConDecl -> TcM DataCon
-
-tcConDecl new_or_data tycon tyvars ctxt
- (ConDecl name ex_tvs ex_ctxt details src_loc)
- = addSrcLoc src_loc $
- tcTyVarBndrs ex_tvs $ \ ex_tvs' -> do
+tcConDecl :: Bool -- True <=> -funbox-strict_fields
+ -> NewOrData -> TyCon -> [TyVar]
+ -> ConDecl Name -> TcM DataCon
+
+tcConDecl unbox_strict NewType tycon tc_tvs -- Newtypes
+ (ConDecl name ex_tvs ex_ctxt details)
+ = ASSERT( null ex_tvs && null (unLoc ex_ctxt) )
+ do { let tc_datacon field_lbls arg_ty
+ = do { arg_ty' <- tcHsKindedType arg_ty -- No bang on newtype
+ ; buildDataCon (unLoc name) False {- Prefix -}
+ True {- Vanilla -} [NotMarkedStrict]
+ (map unLoc field_lbls)
+ tc_tvs [] [arg_ty']
+ tycon (mkTyVarTys tc_tvs) }
+ ; case details of
+ PrefixCon [arg_ty] -> tc_datacon [] arg_ty
+ RecCon [(field_lbl, arg_ty)] -> tc_datacon [field_lbl] arg_ty }
+
+tcConDecl unbox_strict DataType tycon tc_tvs -- Ordinary data types
+ (ConDecl name ex_tvs ex_ctxt details)
+ = tcTyVarBndrs ex_tvs $ \ ex_tvs' -> do
{ ex_ctxt' <- tcHsKindedContext ex_ctxt
- ; unbox_strict <- doptM Opt_UnboxStrictFields
; let
- tc_datacon field_lbls btys
- = do { arg_tys <- mappM (tcHsKindedType . getBangType) btys
- ; buildDataCon name
- (argStrictness unbox_strict tycon btys arg_tys)
- field_lbls
- tyvars ctxt ex_tvs' ex_ctxt'
- arg_tys tycon }
+ is_vanilla = null ex_tvs && null (unLoc ex_ctxt)
+ -- Vanilla iff no ex_tvs and no context
+
+ tc_datacon is_infix field_lbls btys
+ = do { let { bangs = map getBangStrictness btys }
+ ; arg_tys <- mappM tcHsBangType btys
+ ; buildDataCon (unLoc name) is_infix is_vanilla
+ (argStrictness unbox_strict tycon bangs arg_tys)
+ (map unLoc field_lbls)
+ (tc_tvs ++ ex_tvs')
+ ex_ctxt'
+ arg_tys
+ tycon (mkTyVarTys tc_tvs) }
; case details of
- PrefixCon btys -> tc_datacon [] btys
- InfixCon bty1 bty2 -> tc_datacon [] [bty1,bty2]
- RecCon fields -> do { checkTc (null ex_tvs') (exRecConErr name)
+ PrefixCon btys -> tc_datacon False [] btys
+ InfixCon bty1 bty2 -> tc_datacon True [] [bty1,bty2]
+ RecCon fields -> do { checkTc is_vanilla (exRecConErr name)
; let { (field_names, btys) = unzip fields }
- ; tc_datacon field_names btys } }
-
+ ; tc_datacon False field_names btys } }
+
+tcConDecl unbox_strict DataType tycon tc_tvs -- GADTs
+ decl@(GadtDecl name con_ty)
+ = do { traceTc (text "tcConDecl" <+> ppr name)
+ ; (tvs, theta, bangs, arg_tys, tc, res_tys) <- tcLHsConSig con_ty
+
+ ; traceTc (text "tcConDecl1" <+> ppr name)
+ ; let -- Now dis-assemble the type, and check its form
+ is_vanilla = null theta && mkTyVarTys tvs `tcEqTypes` res_tys
+
+ -- Vanilla datacons guarantee to use the same
+ -- type variables as the parent tycon
+ (tvs', arg_tys', res_tys')
+ | is_vanilla = (tc_tvs, substTys subst arg_tys, substTys subst res_tys)
+ | otherwise = (tvs, arg_tys, res_tys)
+ subst = zipTopTvSubst tvs (mkTyVarTys tc_tvs)
+
+ ; traceTc (text "tcConDecl3" <+> ppr name)
+ ; buildDataCon (unLoc name) False {- Not infix -} is_vanilla
+ (argStrictness unbox_strict tycon bangs arg_tys)
+ [{- No field labels -}]
+ tvs' theta arg_tys' tycon res_tys' }
+
+-------------------
+tcStupidTheta :: LHsContext Name -> [LConDecl Name] -> TcM (Maybe ThetaType)
+-- For GADTs we don't allow a context on the data declaration
+-- whereas for standard Haskell style data declarations, we do
+tcStupidTheta ctxt (L _ (ConDecl _ _ _ _) : _)
+ = do { theta <- tcHsKindedContext ctxt; return (Just theta) }
+tcStupidTheta ctxt other -- Includes an empty constructor list
+ = ASSERT( null (unLoc ctxt) ) return Nothing
+
+-------------------
argStrictness :: Bool -- True <=> -funbox-strict_fields
- -> TyCon -> [BangType Name]
+ -> TyCon -> [HsBang]
-> [TcType] -> [StrictnessMark]
-argStrictness unbox_strict tycon btys arg_tys
- = zipWith (chooseBoxingStrategy unbox_strict tycon)
- arg_tys
- (map getBangStrictness btys ++ repeat HsNoBang)
+argStrictness unbox_strict tycon bangs arg_tys
+ = ASSERT( length bangs == length arg_tys )
+ zipWith (chooseBoxingStrategy unbox_strict tycon) arg_tys bangs
-- We attempt to unbox/unpack a strict field when either:
-- (i) The field is marked '!!', or
tied, so we can look at things freely.
\begin{code}
-checkCycleErrs :: [TyClDecl Name] -> TcM ()
+checkCycleErrs :: [LTyClDecl Name] -> TcM ()
checkCycleErrs tyclss
- | null syn_cycles && null cls_cycles
+ | null cls_cycles
= return ()
| otherwise
- = do { mappM_ recSynErr syn_cycles
- ; mappM_ recClsErr cls_cycles
+ = do { mappM_ recClsErr cls_cycles
; failM } -- Give up now, because later checkValidTyCl
-- will loop if the synonym is recursive
where
- (syn_cycles, cls_cycles) = calcCycleErrs tyclss
+ cls_cycles = calcClassCycles tyclss
-checkValidTyCl :: RenamedTyClDecl -> TcM ()
+checkValidTyCl :: TyClDecl Name -> TcM ()
-- We do the validity check over declarations, rather than TyThings
-- only so that we can add a nice context with tcAddDeclCtxt
checkValidTyCl decl
= tcAddDeclCtxt decl $
- do { thing <- tcLookupGlobal (tcdName decl)
+ do { thing <- tcLookupLocatedGlobal (tcdLName decl)
; traceTc (text "Validity of" <+> ppr thing)
; case thing of
ATyCon tc -> checkValidTyCon tc
checkValidTyCon :: TyCon -> TcM ()
checkValidTyCon tc
| isSynTyCon tc
- = addErrCtxt (checkTypeCtxt syn_ctxt syn_rhs) $
- checkValidType syn_ctxt syn_rhs
+ = checkValidType syn_ctxt syn_rhs
| otherwise
= -- Check the context on the data decl
- checkValidTheta (DataTyCtxt name) (tyConTheta tc) `thenM_`
+ checkValidTheta (DataTyCtxt name) (tyConStupidTheta tc) `thenM_`
-- Check arg types of data constructors
- mappM_ checkValidDataCon data_cons `thenM_`
+ mappM_ (checkValidDataCon tc) data_cons `thenM_`
-- Check that fields with the same name share a type
mappM_ check_fields groups
(_, syn_rhs) = getSynTyConDefn tc
data_cons = tyConDataCons tc
- fields = [field | con <- data_cons, field <- dataConFieldLabels con]
- groups = equivClasses cmp_name fields
- cmp_name field1 field2 = fieldLabelName field1 `compare` fieldLabelName field2
+ groups = equivClasses cmp_fld (concatMap get_fields data_cons)
+ cmp_fld (f1,_) (f2,_) = f1 `compare` f2
+ get_fields con = dataConFieldLabels con `zip` dataConOrigArgTys con
+ -- dataConFieldLabels may return the empty list, which is fine
- check_fields fields@(first_field_label : other_fields)
+ check_fields fields@((first_field_label, field_ty) : other_fields)
-- These fields all have the same name, but are from
-- different constructors in the data type
= -- Check that all the fields in the group have the same type
-- NB: this check assumes that all the constructors of a given
-- data type use the same type variables
- checkTc (all (tcEqType field_ty) other_tys) (fieldTypeMisMatch field_name)
- where
- field_ty = fieldLabelType first_field_label
- field_name = fieldLabelName first_field_label
- other_tys = map fieldLabelType other_fields
+ checkTc (all (tcEqType field_ty . snd) other_fields)
+ (fieldTypeMisMatch first_field_label)
-------------------------------
-checkValidDataCon :: DataCon -> TcM ()
-checkValidDataCon con
- = addErrCtxt (dataConCtxt con) (
- checkValidType ctxt (idType (dataConWrapId con)) `thenM_`
+checkValidDataCon :: TyCon -> DataCon -> TcM ()
+checkValidDataCon tc con
+ = addErrCtxt (dataConCtxt con) $
+ do { checkTc (dataConTyCon con == tc) (badDataConTyCon con)
+ ; checkValidType ctxt (idType (dataConWrapId con)) }
+
-- This checks the argument types and
-- ambiguity of the existential context (if any)
- checkFreeness ex_tvs ex_theta)
+ --
+ -- Note [Sept 04] Now that tvs is all the tvs, this
+ -- test doesn't actually check anything
+-- ; checkFreeness tvs ex_theta }
where
ctxt = ConArgCtxt (dataConName con)
- (_, _, ex_tvs, ex_theta, _, _) = dataConSig con
+ (tvs, ex_theta, _, _, _) = dataConSig con
-------------------------------
no_generics = null [() | (_, GenDefMeth) <- op_stuff]
check_op (sel_id, dm)
- = addErrCtxt (classOpCtxt sel_id) (
- checkValidTheta SigmaCtxt (tail theta) `thenM_`
+ = addErrCtxt (classOpCtxt sel_id tau) $ do
+ { checkValidTheta SigmaCtxt (tail theta)
-- The 'tail' removes the initial (C a) from the
-- class itself, leaving just the method type
- checkValidType (FunSigCtxt op_name) tau `thenM_`
+ ; checkValidType (FunSigCtxt op_name) tau
+
+ -- Check that the type mentions at least one of
+ -- the class type variables
+ ; checkTc (any (`elemVarSet` tyVarsOfType tau) tyvars)
+ (noClassTyVarErr cls sel_id)
-- Check that for a generic method, the type of
-- the method is sufficiently simple
- checkTc (dm /= GenDefMeth || validGenericMethodType op_ty)
+ ; checkTc (dm /= GenDefMeth || validGenericMethodType tau)
(badGenericMethodType op_name op_ty)
- )
+ }
where
op_name = idName sel_id
op_ty = idType sel_id
fieldTypeMisMatch field_name
= sep [ptext SLIT("Different constructors give different types for field"), quotes (ppr field_name)]
-checkTypeCtxt ctxt ty
- = vcat [ptext SLIT("In the type:") <+> ppr_ty,
- ptext SLIT("While checking") <+> pprUserTypeCtxt ctxt ]
- where
- -- Hack alert. If there are no tyvars, (ppr sigma_ty) will print
- -- something strange like {Eq k} -> k -> k, because there is no
- -- ForAll at the top of the type. Since this is going to the user
- -- we want it to look like a proper Haskell type even then; hence the hack
- --
- -- This shows up in the complaint about
- -- case C a where
- -- op :: Eq a => a -> a
- ppr_ty | null forall_tvs = pprThetaArrow theta <+> ppr tau
- | otherwise = ppr ty
-
- (forall_tvs, theta, tau) = tcSplitSigmaTy ty
-
dataConCtxt con = sep [ptext SLIT("When checking the data constructor:"),
nest 2 (ex_part <+> pprThetaArrow ex_theta <+> ppr con <+> arg_part)]
where
- (_, _, ex_tvs, ex_theta, arg_tys, _) = dataConSig con
+ (ex_tvs, ex_theta, arg_tys, _, _) = dataConSig con
ex_part | null ex_tvs = empty
| otherwise = ptext SLIT("forall") <+> hsep (map ppr ex_tvs) <> dot
-- The 'ex_theta' part could be non-empty, if the user (bogusly) wrote
[ ppr n <+> dcolon <+> ppr ty
| (n,ty) <- fields `zip` arg_tys]))
-classOpCtxt sel_id = sep [ptext SLIT("When checking the class method:"),
- nest 2 (ppr sel_id <+> dcolon <+> ppr (idType sel_id))]
+classOpCtxt sel_id tau = sep [ptext SLIT("When checking the class method:"),
+ nest 2 (ppr sel_id <+> dcolon <+> ppr tau)]
nullaryClassErr cls
= ptext SLIT("No parameters for class") <+> quotes (ppr cls)
= vcat [ptext SLIT("Too many parameters for class") <+> quotes (ppr cls),
parens (ptext SLIT("Use -fglasgow-exts to allow multi-parameter classes"))]
+noClassTyVarErr clas op
+ = sep [ptext SLIT("The class method") <+> quotes (ppr op),
+ ptext SLIT("mentions none of the type variables of the class") <+>
+ ppr clas <+> hsep (map ppr (classTyVars clas))]
+
genericMultiParamErr clas
= ptext SLIT("The multi-parameter class") <+> quotes (ppr clas) <+>
ptext SLIT("cannot have generic methods")
4 (vcat [ppr op <+> dcolon <+> ppr op_ty,
ptext SLIT("You can only use type variables, arrows, and tuples")])
-recSynErr tcs
- = addSrcLoc (getSrcLoc (head tcs)) $
+recSynErr syn_decls
+ = setSrcSpan (getLoc (head sorted_decls)) $
addErr (sep [ptext SLIT("Cycle in type synonym declarations:"),
- nest 2 (vcat (map ppr_thing tcs))])
+ nest 2 (vcat (map ppr_decl sorted_decls))])
+ where
+ sorted_decls = sortLocated syn_decls
+ ppr_decl (L loc decl) = ppr loc <> colon <+> ppr decl
-recClsErr clss
- = addSrcLoc (getSrcLoc (head clss)) $
+recClsErr cls_decls
+ = setSrcSpan (getLoc (head sorted_decls)) $
addErr (sep [ptext SLIT("Cycle in class declarations (via superclasses):"),
- nest 2 (vcat (map ppr_thing clss))])
-
-ppr_thing :: Name -> SDoc
-ppr_thing n = ppr n <+> parens (ppr (getSrcLoc n))
+ nest 2 (vcat (map ppr_decl sorted_decls))])
+ where
+ sorted_decls = sortLocated cls_decls
+ ppr_decl (L loc decl) = ppr loc <> colon <+> ppr (decl { tcdSigs = [] })
+sortLocated :: [Located a] -> [Located a]
+sortLocated things = sortLe le things
+ where
+ le (L l1 _) (L l2 _) = l1 <= l2
exRecConErr name
- = ptext SLIT("Can't combine named fields with locally-quantified type variables")
+ = ptext SLIT("Can't combine named fields with locally-quantified type variables or context")
$$
(ptext SLIT("In the declaration of data constructor") <+> ppr name)
+
+badDataConTyCon data_con
+ = hang (ptext SLIT("Data constructor does not return its parent type:"))
+ 2 (ppr data_con)
+
+badGadtDecl tc_name
+ = vcat [ ptext SLIT("Illegal generalised algebraic data declaration for") <+> quotes (ppr tc_name)
+ , nest 2 (parens $ ptext SLIT("Use -fglasgow-exts to allow GADTs")) ]
\end{code}
projects / ghc-hetmet.git / blobdiff