#include "HsVersions.h"
import HsSyn ( TyClDecl(..), HsConDetails(..), HsTyVarBndr(..),
- ConDecl(..), Sig(..), BangType(..), HsBang(..),
- tyClDeclTyVars, getBangType, getBangStrictness, isSynDecl,
- LTyClDecl, tcdName, LHsTyVarBndr
+ ConDecl(..), Sig(..), , NewOrData(..),
+ tyClDeclTyVars, isSynDecl, LConDecl,
+ LTyClDecl, tcdName, LHsTyVarBndr, LHsContext
)
-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(..),
tcLookupLocated, tcLookupLocatedGlobal,
tcExtendRecEnv, tcLookupTyVar )
import TcTyDecls ( calcTyConArgVrcs, calcRecFlags, calcClassCycles, calcSynCycles )
import TcClassDcl ( tcClassSigs, tcAddDeclCtxt )
-import TcHsType ( kcHsTyVars, kcHsLiftedSigType, kcHsSigType, kcHsType,
- kcHsContext, tcTyVarBndrs, tcHsKindedType, tcHsKindedContext )
+import TcHsType ( kcHsTyVars, kcHsLiftedSigType, kcHsType,
+ kcHsContext, tcTyVarBndrs, tcHsKindedType, tcHsKindedContext,
+ kcHsSigType, tcHsBangType, tcLHsConSig )
import TcMType ( newKindVar, checkValidTheta, checkValidType, checkFreeness,
UserTypeCtxt(..), SourceTyCtxt(..) )
import TcUnify ( unifyKind )
-import TcType ( TcKind, ThetaType, TcType, tyVarsOfType,
- mkArrowKind, liftedTypeKind,
+import TcType ( TcKind, ThetaType, TcType, tyVarsOfType,
+ mkArrowKind, liftedTypeKind, mkTyVarTys, tcEqTypes,
tcSplitSigmaTy, tcEqType )
import Type ( splitTyConApp_maybe, pprThetaArrow, pprParendType )
-import FieldLabel ( fieldLabelName, fieldLabelType )
import Generics ( validGenericMethodType, canDoGenerics )
import Class ( Class, className, classTyCon, DefMeth(..), classBigSig, classTyVars )
-import TyCon ( TyCon, ArgVrcs, DataConDetails(..),
+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 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 )
@TyThing@s. @rec_vrcs@ is a finite map from @Name@s to @ArgVrcs@s.
\begin{code}
-tcTyAndClassDecls :: [LTyClDecl Name]
+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
-
+ ; 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 }
{ (kc_syn_decls, kc_alg_decls) <- kcTyClDecls syn_decls alg_decls
; let { calc_vrcs = calcTyConArgVrcs (rec_syn_tycons ++ rec_alg_tyclss)
- ; calc_rec = calcRecFlags 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
do { ex_ctxt' <- kcHsContext ex_ctxt
; details' <- kc_con_details details
; 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_larg_ty btys ; return (PrefixCon btys') }
kc_field (fld, bty) = do { bty' <- kc_larg_ty bty ; return (fld, bty') }
- kc_larg_ty = wrapLocM kc_arg_ty
-
- 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 $ \ tvs' ->
do { tc_ty_thing <- tcLookupLocated (tcdLName decl)
; let tc_kind = case tc_ty_thing of { AThing k -> k }
; unifyKind tc_kind (foldr (mkArrowKind . kindedTyVarKind)
- liftedTypeKind 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 (L _ (KindedTyVar _ k)) = k
\end{code}
(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 (addLocM (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 {tcdLName = L _ class_name, tcdTyVars = tvs,
= returnM (ATyCon (mkForeignTyCon tc_name tc_ext_name liftedTypeKind 0 []))
-----------------------------------
-tcConDecl :: NewOrData -> TyCon -> [TyVar] -> ThetaType
+tcConDecl :: Bool -- True <=> -funbox-strict_fields
+ -> NewOrData -> TyCon -> [TyVar]
-> ConDecl Name -> TcM DataCon
-tcConDecl new_or_data tycon tyvars ctxt
- (ConDecl name ex_tvs ex_ctxt details)
+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 { let { ubtys = map unLoc btys }
- ; arg_tys <- mappM (tcHsKindedType . getBangType) ubtys
- ; buildDataCon (unLoc name)
- (argStrictness unbox_strict tycon ubtys arg_tys)
+ 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)
- tyvars ctxt ex_tvs' ex_ctxt'
- arg_tys tycon }
+ (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
= 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
-------------------------------
-- 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
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
badGenericMethodType op op_ty
= hang (ptext SLIT("Generic method type is too complex"))
4 (vcat [ppr op <+> dcolon <+> ppr op_ty,
- ptext SLIT("You can only use type variables, arrows, and tuples")])
+ ptext SLIT("You can only use type variables, arrows, lists, and tuples")])
recSynErr syn_decls
- = addSrcSpan (getLoc (head syn_decls)) $
+ = setSrcSpan (getLoc (head sorted_decls)) $
addErr (sep [ptext SLIT("Cycle in type synonym declarations:"),
- nest 2 (vcat (map ppr_decl syn_decls))])
+ 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 cls_decls
- = addSrcSpan (getLoc (head cls_decls)) $
+ = setSrcSpan (getLoc (head sorted_decls)) $
addErr (sep [ptext SLIT("Cycle in class declarations (via superclasses):"),
- nest 2 (vcat (map ppr_decl cls_decls))])
+ 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