)
import HsTypes ( HsBang(..), getBangStrictness )
import BasicTypes ( RecFlag(..), StrictnessMark(..) )
-import HscTypes ( implicitTyThings )
+import HscTypes ( implicitTyThings, ModDetails )
import BuildTyCl ( buildClass, buildAlgTyCon, buildSynTyCon, buildDataCon,
mkDataTyConRhs, mkNewTyConRhs )
import TcRnMonad
import Type ( splitTyConApp_maybe, pprThetaArrow, pprParendType )
import Generics ( validGenericMethodType, canDoGenerics )
import Class ( Class, className, classTyCon, DefMeth(..), classBigSig, classTyVars )
-import TyCon ( TyCon, ArgVrcs,
+import TyCon ( TyCon, ArgVrcs, AlgTyConRhs( AbstractTyCon ),
tyConDataCons, mkForeignTyCon, isProductTyCon, isRecursiveTyCon,
tyConStupidTheta, getSynTyConDefn, isSynTyCon, tyConName )
import DataCon ( DataCon, dataConWrapId, dataConName, dataConSig,
import SrcLoc ( Located(..), unLoc, getLoc )
import ListSetOps ( equivClasses )
import Digraph ( SCC(..) )
-import CmdLineOpts ( DynFlag( Opt_GlasgowExts, Opt_Generics, Opt_UnboxStrictFields ) )
+import DynFlags ( 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 :: [Name] -> [LTyClDecl Name]
+tcTyAndClassDecls :: ModDetails -> [LTyClDecl Name]
-> TcM TcGblEnv -- Input env extended by types and classes
-- and their implicit Ids,DataCons
-tcTyAndClassDecls boot_names decls
+tcTyAndClassDecls boot_details 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)
+ ; traceTc (text "tcTyAndCl" <+> ppr mod)
; (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 boot_names rec_alg_tyclss
+ ; calc_rec = calcRecFlags boot_details 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
; return (ConDecl name ex_tvs' ex_ctxt' details')}
kc_con_decl (GadtDecl name ty)
= do { ty' <- kcHsSigType ty
+ ; traceTc (text "kc_con_decl" <+> ppr name <+> ppr ty')
; return (GadtDecl name ty') }
kc_con_details (PrefixCon btys)
kcHsTyVars (tyClDeclTyVars decl) $ \ kinded_tvs ->
do { tc_ty_thing <- tcLookupLocated (tcdLName decl)
; let tc_kind = case tc_ty_thing of { AThing k -> k }
+ ;
+ ; traceTc (text "kcbody" <+> ppr decl <+> ppr tc_kind <+> ppr (map kindedTyVarKind kinded_tvs) <+> ppr (result_kind decl))
; unifyKind tc_kind (foldr (mkArrowKind . kindedTyVarKind)
(result_kind decl)
kinded_tvs)
{ extra_tvs <- tcDataKindSig mb_ksig
; let final_tvs = tvs' ++ extra_tvs
; stupid_theta <- tcStupidTheta ctxt cons
+
; want_generic <- doptM Opt_Generics
+ ; unbox_strict <- doptM Opt_UnboxStrictFields
+ ; gla_exts <- doptM Opt_GlasgowExts
+ ; is_boot <- tcIsHsBoot -- Are we compiling an hs-boot file?
+
+ -- Check that we don't use GADT syntax in H98 world
+ ; checkTc (gla_exts || h98_syntax) (badGadtDecl tc_name)
+
+ -- Check that there's at least one condecl,
+ -- or else we're reading an interface file, or -fglasgow-exts
+ ; checkTc (not (null cons) || gla_exts || is_boot)
+ (emptyConDeclsErr tc_name)
+
; tycon <- fixM (\ tycon -> do
- { 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 final_tvs)) cons
- ; let tc_rhs = case new_or_data of
+ { data_cons <- mappM (addLocM (tcConDecl unbox_strict new_or_data
+ tycon final_tvs))
+ cons
+ ; let tc_rhs
+ | null cons && is_boot -- In a hs-boot file, empty cons means
+ = AbstractTyCon -- "don't know"; hence Abstract
+ | otherwise
+ = case new_or_data of
DataType -> mkDataTyConRhs stupid_theta data_cons
NewType -> ASSERT( isSingleton data_cons )
mkNewTyConRhs tycon (head data_cons)
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
+ ; (tvs, theta, bangs, arg_tys, data_tc, res_tys) <- tcLHsConSig con_ty
; traceTc (text "tcConDecl1" <+> ppr name)
; let -- Now dis-assemble the type, and check its form
; 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' }
+ tvs' theta arg_tys' data_tc res_tys' }
+ -- NB: we put data_tc, the type constructor gotten from the constructor
+ -- type signature into the data constructor; that way checkValidDataCon
+ -- can complain if it's wrong.
-------------------
tcStupidTheta :: LHsContext Name -> [LConDecl Name] -> TcM (Maybe ThetaType)
(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)
+ = hang (ptext SLIT("Data constructor") <+> quotes (ppr data_con) <+>
+ ptext SLIT("returns type") <+> quotes (ppr (dataConTyCon data_con)))
+ 2 (ptext SLIT("instead of its parent type"))
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")) ]
+
+emptyConDeclsErr tycon
+ = sep [quotes (ppr tycon) <+> ptext SLIT("has no constructors"),
+ nest 4 (ptext SLIT("(-fglasgow-exts permits this)"))]
\end{code}
projects / ghc-hetmet.git / blobdiff