#include "HsVersions.h"
-import CmdLineOpts ( DynFlags, DynFlag(..), dopt )
-import HsSyn ( TyClDecl(..),
- ConDecl(..), Sig(..), HsPred(..),
- tyClDeclName, hsTyVarNames, tyClDeclTyVars,
- isIfaceSigDecl, isClassDecl, isSynDecl, isClassOpSig
+import HsSyn ( TyClDecl(..), HsConDetails(..), HsTyVarBndr(..),
+ ConDecl(..), Sig(..), , NewOrData(..), ResType(..),
+ tyClDeclTyVars, isSynDecl, hsConArgs,
+ LTyClDecl, tcdName, hsTyVarName, LHsTyVarBndr
)
-import RnHsSyn ( RenamedTyClDecl, tyClDeclFVs )
-import BasicTypes ( RecFlag(..), NewOrData(..), isRec )
-import HscTypes ( implicitTyThingIds )
-
-import TcMonad
-import TcEnv ( TcEnv, RecTcEnv, TcTyThing(..), TyThing(..), TyThingDetails(..),
- tcExtendKindEnv, tcLookup, tcExtendGlobalEnv, tcExtendGlobalValEnv )
-import TcTyDecls ( tcTyDecl1, kcConDetails )
-import TcClassDcl ( tcClassDecl1 )
-import TcInstDcls ( tcAddDeclCtxt )
-import TcMonoType ( kcHsTyVars, kcHsType, kcHsLiftedSigType, kcHsContext, mkTyClTyVars )
-import TcMType ( unifyKind, newKindVar, zonkKindEnv )
-import TcType ( Type, Kind, mkArrowKind, liftedTypeKind, zipFunTys )
-import Variance ( calcTyConArgVrcs )
-import Class ( Class, mkClass, classTyCon )
-import TyCon ( TyCon, ArgVrcs, AlgTyConFlavour(..),
- tyConKind, tyConDataCons,
- mkSynTyCon, mkAlgTyCon, mkClassTyCon, mkForeignTyCon,
- isRecursiveTyCon )
-import DataCon ( dataConOrigArgTys )
-import Var ( varName )
-import FiniteMap
-import Digraph ( stronglyConnComp, SCC(..) )
-import Name ( Name, getSrcLoc, isTyVarName )
-import NameEnv
-import NameSet
+import HsTypes ( HsBang(..), getBangStrictness )
+import BasicTypes ( RecFlag(..), StrictnessMark(..) )
+import HscTypes ( implicitTyThings, ModDetails )
+import BuildTyCl ( buildClass, buildAlgTyCon, buildSynTyCon, buildDataCon,
+ mkDataTyConRhs, mkNewTyConRhs )
+import TcRnMonad
+import TcEnv ( TyThing(..),
+ tcLookupLocated, tcLookupLocatedGlobal,
+ tcExtendGlobalEnv, tcExtendKindEnv, tcExtendKindEnvTvs,
+ tcExtendRecEnv, tcLookupTyVar )
+import TcTyDecls ( calcTyConArgVrcs, calcRecFlags, calcClassCycles, calcSynCycles )
+import TcClassDcl ( tcClassSigs, tcAddDeclCtxt )
+import TcHsType ( kcHsTyVars, kcHsLiftedSigType, kcHsType,
+ kcHsContext, tcTyVarBndrs, tcHsKindedType, tcHsKindedContext,
+ kcHsSigType, tcHsBangType, tcLHsConResTy, tcDataKindSig )
+import TcMType ( newKindVar, checkValidTheta, checkValidType,
+ -- checkFreeness,
+ UserTypeCtxt(..), SourceTyCtxt(..) )
+import TcType ( TcKind, TcType, tyVarsOfType, mkPhiTy,
+ mkArrowKind, liftedTypeKind, mkTyVarTys,
+ tcSplitSigmaTy, tcEqTypes, tcGetTyVar_maybe )
+import Type ( splitTyConApp_maybe,
+ -- pprParendType, pprThetaArrow
+ )
+import Kind ( mkArrowKinds, splitKindFunTys )
+import Generics ( validGenericMethodType, canDoGenerics )
+import Class ( Class, className, classTyCon, DefMeth(..), classBigSig, classTyVars )
+import TyCon ( TyCon, ArgVrcs, AlgTyConRhs( AbstractTyCon ),
+ tyConDataCons, mkForeignTyCon, isProductTyCon, isRecursiveTyCon,
+ tyConStupidTheta, synTyConRhs, isSynTyCon, tyConName )
+import DataCon ( DataCon, dataConWrapId, dataConName,
+ dataConFieldLabels, dataConTyCon,
+ dataConTyVars, dataConFieldType, dataConResTys )
+import Var ( TyVar, idType, idName )
+import VarSet ( elemVarSet, mkVarSet )
+import Name ( Name, getSrcLoc )
import Outputable
-import Maybes ( mapMaybe )
-import ErrUtils ( Message )
-import HsDecls ( getClassDeclSysNames )
-import Generics ( mkTyConGenInfo )
+import Maybe ( isJust )
+import Maybes ( expectJust )
+import Unify ( tcMatchTys, tcMatchTyX )
+import Util ( zipLazy, isSingleton, notNull, sortLe )
+import List ( partition )
+import SrcLoc ( Located(..), unLoc, getLoc, srcLocSpan )
+import ListSetOps ( equivClasses )
+import List ( delete )
+import Digraph ( SCC(..) )
+import DynFlags ( DynFlag( Opt_GlasgowExts, Opt_Generics,
+ Opt_UnboxStrictFields ) )
\end{code}
%* *
%************************************************************************
-The main function
-~~~~~~~~~~~~~~~~~
-\begin{code}
-tcTyAndClassDecls :: RecTcEnv -- Knot tying stuff
- -> [RenamedTyClDecl]
- -> TcM TcEnv
-
-tcTyAndClassDecls unf_env decls
- = sortByDependency decls `thenTc` \ groups ->
- tcGroups unf_env groups
-
-tcGroups unf_env []
- = tcGetEnv `thenNF_Tc` \ env ->
- returnTc env
-
-tcGroups unf_env (group:groups)
- = tcGroup unf_env group `thenTc` \ env ->
- tcSetEnv env $
- tcGroups unf_env groups
-\end{code}
-
Dealing with a group
~~~~~~~~~~~~~~~~~~~~
Consider a mutually-recursive group, binding
to tcTyClDecl1.
-Step 6: tcTyClDecl1 again
- For a recursive group only, check all the decls again, just
- but this time with the wimp flag off. Now we can check things
- like whether a function argument is an unlifted tuple, looking
- through type synonyms properly. We can't do that in Step 5.
-
-Step 7: Extend environment
+Step 6: Extend environment
We extend the type environment with bindings not only for the TyCons and Classes,
but also for their "implicit Ids" like data constructors and class selectors
+Step 7: checkValidTyCl
+ For a recursive group only, check all the decls again, just
+ to check all the side conditions on validity. We could not
+ do this before because we were in a mutually recursive knot.
+
+
The knot-tying parameters: @rec_details_list@ is an alist mapping @Name@s to
@TyThing@s. @rec_vrcs@ is a finite map from @Name@s to @ArgVrcs@s.
\begin{code}
-tcGroup :: RecTcEnv -> SCC RenamedTyClDecl -> TcM TcEnv
-tcGroup unf_env scc
- = getDOptsTc `thenTc` \ dflags ->
- -- Step 1
- mapNF_Tc getInitialKind decls `thenNF_Tc` \ initial_kinds ->
-
- -- Step 2
- tcExtendKindEnv initial_kinds (mapTc kcTyClDecl decls) `thenTc_`
-
- -- Step 3
- zonkKindEnv initial_kinds `thenNF_Tc` \ final_kinds ->
-
- -- Tie the knot
- traceTc (text "starting" <+> ppr final_kinds) `thenTc_`
- fixTc ( \ ~(rec_details_list, _, _) ->
- -- Step 4
- let
- kind_env = mkNameEnv final_kinds
- rec_details = mkNameEnv rec_details_list
-
- tyclss, all_tyclss :: [TyThing]
- tyclss = map (buildTyConOrClass dflags is_rec kind_env
- rec_vrcs rec_details) decls
-
- -- Add the tycons that come from the classes
- -- We want them in the environment because
- -- they are mentioned in interface files
- all_tyclss = [ ATyCon (classTyCon clas) | AClass clas <- tyclss]
- ++ tyclss
-
- -- Calculate variances, and (yes!) feed back into buildTyConOrClass.
- rec_vrcs = calcTyConArgVrcs [tc | ATyCon tc <- all_tyclss]
- in
- -- Step 5
- tcExtendGlobalEnv all_tyclss $
- mapTc (tcTyClDecl1 is_rec unf_env) decls `thenTc` \ tycls_details ->
-
- -- Return results
- tcGetEnv `thenNF_Tc` \ env ->
- returnTc (tycls_details, all_tyclss, env)
- ) `thenTc` \ (_, all_tyclss, env) ->
-
- tcSetEnv env $
-
- traceTc (text "ready for pass 2" <+> ppr (isRec is_rec)) `thenTc_`
-
- -- Step 6
- -- For a recursive group, check all the types again,
- -- this time with the wimp flag off
- (if isRec is_rec then
- mapTc_ (tcTyClDecl1 NonRecursive unf_env) decls
- else
- returnTc ()
- ) `thenTc_`
-
- traceTc (text "done") `thenTc_`
-
- -- Step 7
- -- Extend the environment with the final TyCons/Classes
- -- and their implicit Ids
- tcExtendGlobalValEnv (implicitTyThingIds all_tyclss) tcGetEnv
-
+tcTyAndClassDecls :: ModDetails -> [LTyClDecl Name]
+ -> TcM TcGblEnv -- Input env extended by types and classes
+ -- and their implicit Ids,DataCons
+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)
+ ; (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_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
+ ; 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 (syn_tycons ++ alg_tyclss) $ do
+
+ -- Perform the validity check
+ { traceTc (text "ready for validity check")
+ ; 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 alg_tyclss }
+ ; traceTc ((text "Adding" <+> ppr alg_tyclss) $$ (text "and" <+> ppr implicit_things))
+ ; tcExtendGlobalEnv implicit_things getGblEnv
+ }}
+
+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
+-- make a TypeEnv for the new things
+mkGlobalThings decls things
+ = map mk_thing (decls `zipLazy` things)
where
- is_rec = case scc of
- AcyclicSCC _ -> NonRecursive
- CyclicSCC _ -> Recursive
-
- decls = case scc of
- AcyclicSCC decl -> [decl]
- CyclicSCC decls -> decls
-
-tcTyClDecl1 is_rec unf_env decl
- | isClassDecl decl = tcAddDeclCtxt decl (tcClassDecl1 is_rec unf_env decl)
- | otherwise = tcAddDeclCtxt decl (tcTyDecl1 is_rec unf_env decl)
-\end{code}
-
-
-%************************************************************************
-%* *
-\subsection{Step 1: Initial environment}
-%* *
-%************************************************************************
-
-\begin{code}
-getInitialKind :: RenamedTyClDecl -> NF_TcM (Name, TcKind)
-getInitialKind decl
- = kcHsTyVars (tyClDeclTyVars decl) `thenNF_Tc` \ arg_kinds ->
- newKindVar `thenNF_Tc` \ result_kind ->
- returnNF_Tc (tcdName decl, mk_kind arg_kinds result_kind)
-
-mk_kind tvs_w_kinds res_kind = foldr (mkArrowKind . snd) res_kind tvs_w_kinds
+ mk_thing (L _ (ClassDecl {tcdLName = L _ name}), ~(AClass cl))
+ = (name, AClass cl)
+ mk_thing (L _ decl, ~(ATyCon tc))
+ = (tcdName decl, ATyCon tc)
\end{code}
%************************************************************************
%* *
-\subsection{Step 2: Kind checking}
+ Kind checking
%* *
%************************************************************************
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}
-kcTyClDecl :: RenamedTyClDecl -> TcM ()
-
-kcTyClDecl decl@(TySynonym {tcdSynRhs = rhs})
- = kcTyClDeclBody decl $ \ result_kind ->
- kcHsType rhs `thenTc` \ rhs_kind ->
- unifyKind result_kind rhs_kind
-
-kcTyClDecl (ForeignType {}) = returnTc ()
+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.
-kcTyClDecl decl@(TyData {tcdND = new_or_data, tcdCtxt = context, tcdCons = con_decls})
- = kcTyClDeclBody decl $ \ result_kind ->
- kcHsContext context `thenTc_`
- mapTc_ kc_con_decl con_decls
+\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) }}}
+
+------------------------------------------------------------------------
+getInitialKind :: LTyClDecl Name -> TcM (Name, TcKind)
+-- Only for data type and class declarations
+-- Get as much info as possible from the data or class decl,
+-- so as to maximise usefulness of error messages
+getInitialKind (L _ decl)
+ = do { arg_kinds <- mapM (mk_arg_kind . unLoc) (tyClDeclTyVars decl)
+ ; res_kind <- mk_res_kind decl
+ ; return (tcdName decl, mkArrowKinds arg_kinds res_kind) }
where
- kc_con_decl (ConDecl _ _ ex_tvs ex_ctxt details loc)
- = kcHsTyVars ex_tvs `thenNF_Tc` \ kind_env ->
- tcExtendKindEnv kind_env $
- kcConDetails new_or_data ex_ctxt details
-
-kcTyClDecl decl@(ClassDecl {tcdCtxt = context, tcdSigs = class_sigs})
- = kcTyClDeclBody decl $ \ result_kind ->
- kcHsContext context `thenTc_`
- mapTc_ kc_sig (filter isClassOpSig class_sigs)
+ mk_arg_kind (UserTyVar _) = newKindVar
+ mk_arg_kind (KindedTyVar _ kind) = return kind
+
+ mk_res_kind (TyData { tcdKindSig = Just kind }) = return kind
+ -- On GADT-style declarations we allow a kind signature
+ -- data T :: *->* where { ... }
+ mk_res_kind other = return liftedTypeKind
+
+
+----------------
+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
+
+kindedTyVarKind (L _ (KindedTyVar _ k)) = k
+
+------------------------------------------------------------------------
+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 $ \ tvs' ->
+ do { ctxt' <- kcHsContext ctxt
+ ; cons' <- mappM (wrapLocM kc_con_decl) cons
+ ; return (decl {tcdTyVars = tvs', tcdCtxt = ctxt', tcdCons = cons'}) }
where
- kc_sig (ClassOpSig _ _ op_ty loc) = kcHsLiftedSigType op_ty
-
-kcTyClDeclBody :: RenamedTyClDecl -> (Kind -> TcM a) -> TcM a
+ kc_con_decl (ConDecl name expl ex_tvs ex_ctxt details res) = do
+ kcHsTyVars ex_tvs $ \ex_tvs' -> do
+ ex_ctxt' <- kcHsContext ex_ctxt
+ details' <- kc_con_details details
+ res' <- case res of
+ ResTyH98 -> return ResTyH98
+ ResTyGADT ty -> return . ResTyGADT =<< kcHsSigType ty
+ return (ConDecl name expl ex_tvs' ex_ctxt' details' res')
+
+ kc_con_details (PrefixCon btys)
+ = do { btys' <- mappM kc_larg_ty btys ; return (PrefixCon btys') }
+ kc_con_details (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_larg_ty bty ; return (fld, bty') }
+
+ 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 { is_boot <- tcIsHsBoot
+ ; checkTc (not is_boot) badBootClassDeclErr
+ ; ctxt' <- kcHsContext ctxt
+ ; sigs' <- mappM (wrapLocM kc_sig) sigs
+ ; return (decl {tcdTyVars = tvs', tcdCtxt = ctxt', tcdSigs = sigs'}) }
+ where
+ kc_sig (TypeSig nm op_ty) = do { op_ty' <- kcHsLiftedSigType op_ty
+ ; return (TypeSig nm op_ty') }
+ kc_sig other_sig = return other_sig
+
+kcTyClDecl decl@(ForeignType {})
+ = return decl
+
+kcTyClDeclBody :: TyClDecl Name
+ -> ([LHsTyVarBndr Name] -> TcM a)
+ -> TcM a
+-- getInitialKind has made a suitably-shaped kind for the type or class
+-- Unpack it, and attribute those kinds to the type variables
-- 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
+ -- check the result kind matches
kcTyClDeclBody decl thing_inside
= tcAddDeclCtxt decl $
- tcLookup (tcdName decl) `thenNF_Tc` \ thing ->
- let
- kind = case thing of
- AGlobal (ATyCon tc) -> tyConKind tc
- AGlobal (AClass cl) -> tyConKind (classTyCon cl)
- AThing kind -> kind
- -- For some odd reason, a class doesn't include its kind
-
- (tyvars_w_kinds, result_kind) = zipFunTys (hsTyVarNames (tyClDeclTyVars decl)) kind
- in
- tcExtendKindEnv tyvars_w_kinds (thing_inside result_kind)
+ do { tc_ty_thing <- tcLookupLocated (tcdLName decl)
+ ; let tc_kind = case tc_ty_thing of { AThing k -> k }
+ (kinds, _) = splitKindFunTys tc_kind
+ hs_tvs = tcdTyVars decl
+ kinded_tvs = ASSERT( length kinds >= length hs_tvs )
+ [ L loc (KindedTyVar (hsTyVarName tv) k)
+ | (L loc tv, k) <- zip hs_tvs kinds]
+ ; tcExtendKindEnvTvs kinded_tvs (thing_inside kinded_tvs) }
\end{code}
%************************************************************************
%* *
-\subsection{Step 4: Building the tycon/class}
+\subsection{Type checking}
%* *
%************************************************************************
\begin{code}
-buildTyConOrClass
- :: DynFlags
- -> RecFlag -> NameEnv Kind
- -> FiniteMap TyCon ArgVrcs -> NameEnv TyThingDetails
- -> RenamedTyClDecl -> TyThing
-
-buildTyConOrClass dflags is_rec kenv rec_vrcs rec_details
- (TySynonym {tcdName = tycon_name, tcdTyVars = tyvar_names})
- = ATyCon tycon
+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)
+ -> TyClDecl Name -> TcM TyThing
+
+tcTyClDecl calc_vrcs calc_isrec decl
+ = tcAddDeclCtxt decl (tcTyClDecl1 calc_vrcs calc_isrec decl)
+
+tcTyClDecl1 calc_vrcs calc_isrec
+ (TyData {tcdND = new_or_data, tcdCtxt = ctxt, tcdTyVars = tvs,
+ tcdLName = L _ tc_name, tcdKindSig = mb_ksig, tcdCons = cons})
+ = tcTyVarBndrs tvs $ \ tvs' -> do
+ { extra_tvs <- tcDataKindSig mb_ksig
+ ; let final_tvs = tvs' ++ extra_tvs
+ ; stupid_theta <- tcHsKindedContext ctxt
+ ; 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)
+
+ -- Check that a newtype has exactly one constructor
+ ; checkTc (new_or_data == DataType || isSingleton cons)
+ (newtypeConError tc_name (length cons))
+
+ ; tycon <- fixM (\ tycon -> do
+ { 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 data_cons
+ NewType -> ASSERT( isSingleton data_cons )
+ mkNewTyConRhs tycon (head data_cons)
+ ; buildAlgTyCon tc_name final_tvs stupid_theta tc_rhs arg_vrcs is_rec
+ (want_generic && canDoGenerics data_cons)
+ })
+ ; return (ATyCon tycon)
+ }
where
- tycon = mkSynTyCon tycon_name tycon_kind arity tyvars rhs_ty argvrcs
- tycon_kind = lookupNameEnv_NF kenv tycon_name
- arity = length tyvar_names
- tyvars = mkTyClTyVars tycon_kind tyvar_names
- SynTyDetails rhs_ty = lookupNameEnv_NF rec_details tycon_name
- argvrcs = lookupWithDefaultFM rec_vrcs bogusVrcs tycon
-
-buildTyConOrClass dflags is_rec kenv rec_vrcs rec_details
- (TyData {tcdND = data_or_new, tcdName = tycon_name, tcdTyVars = tyvar_names,
- tcdNCons = nconstrs, tcdSysNames = sys_names})
- = ATyCon tycon
+ arg_vrcs = calc_vrcs tc_name
+ is_rec = calc_isrec tc_name
+ h98_syntax = case cons of -- All constructors have same shape
+ L _ (ConDecl { con_res = ResTyGADT _ }) : _ -> False
+ other -> True
+
+tcTyClDecl1 calc_vrcs calc_isrec
+ (ClassDecl {tcdLName = L _ class_name, tcdTyVars = tvs,
+ tcdCtxt = ctxt, tcdMeths = meths,
+ tcdFDs = fundeps, tcdSigs = sigs} )
+ = tcTyVarBndrs tvs $ \ tvs' -> do
+ { ctxt' <- tcHsKindedContext ctxt
+ ; 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
+ -- hold of the name of the class TyCon, which we
+ -- need to look up its recursiveness and variance
+ tycon_name = tyConName (classTyCon clas)
+ tc_isrec = calc_isrec tycon_name
+ tc_vrcs = calc_vrcs tycon_name
+ in
+ buildClass class_name tvs' ctxt' fds'
+ sig_stuff tc_isrec tc_vrcs)
+ ; return (AClass clas) }
where
- tycon = mkAlgTyCon tycon_name tycon_kind tyvars ctxt argvrcs
- data_cons nconstrs sel_ids
- flavour is_rec gen_info
-
- gen_info | not (dopt Opt_Generics dflags) = Nothing
- | otherwise = mkTyConGenInfo tycon sys_names
-
- DataTyDetails ctxt data_cons sel_ids = lookupNameEnv_NF rec_details tycon_name
-
- tycon_kind = lookupNameEnv_NF kenv tycon_name
- tyvars = mkTyClTyVars tycon_kind tyvar_names
- argvrcs = lookupWithDefaultFM rec_vrcs bogusVrcs tycon
-
- -- Watch out! mkTyConApp asks whether the tycon is a NewType,
- -- so flavour has to be able to answer this question without consulting rec_details
- flavour = case data_or_new of
- NewType -> NewTyCon (mkNewTyConRep tycon)
- DataType | all (null . dataConOrigArgTys) data_cons -> EnumTyCon
- | otherwise -> DataTyCon
- -- NB (null . dataConOrigArgTys). It used to say isNullaryDataCon
- -- but that looks at the *representation* arity, and that in turn
- -- depends on deciding whether to unpack the args, and that
- -- depends on whether it's a data type or a newtype --- so
- -- in the recursive case we can get a loop. This version is simple!
-
-buildTyConOrClass dflags is_rec kenv rec_vrcs rec_details
- (ForeignType {tcdName = tycon_name, tcdExtName = tycon_ext_name})
- = ATyCon (mkForeignTyCon tycon_name tycon_ext_name liftedTypeKind 0 [])
-
-buildTyConOrClass dflags is_rec kenv rec_vrcs rec_details
- (ClassDecl {tcdName = class_name, tcdTyVars = tyvar_names,
- tcdFDs = fundeps, tcdSysNames = name_list} )
- = AClass clas
+ tc_fundep (tvs1, tvs2) = do { tvs1' <- mappM tcLookupTyVar tvs1 ;
+ ; tvs2' <- mappM tcLookupTyVar tvs2 ;
+ ; return (tvs1', tvs2') }
+
+
+tcTyClDecl1 calc_vrcs calc_isrec
+ (ForeignType {tcdLName = L _ tc_name, tcdExtName = tc_ext_name})
+ = returnM (ATyCon (mkForeignTyCon tc_name tc_ext_name liftedTypeKind 0 []))
+
+-----------------------------------
+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 ResTyH98)
+ = 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) }
+
+ -- Check that a newtype has no existential stuff
+ ; checkTc (null ex_tvs && null (unLoc ex_ctxt)) (newtypeExError name)
+
+ ; case details of
+ PrefixCon [arg_ty] -> tc_datacon [] arg_ty
+ RecCon [(field_lbl, arg_ty)] -> tc_datacon [field_lbl] arg_ty
+ other -> failWithTc (newtypeFieldErr name (length (hsConArgs details)))
+ -- Check that the constructor has exactly one field
+ }
+
+tcConDecl unbox_strict DataType tycon tc_tvs -- Data types
+ (ConDecl name _ tvs ctxt details res_ty)
+ = tcTyVarBndrs tvs $ \ tvs' -> do
+ { ctxt' <- tcHsKindedContext ctxt
+ ; (data_tc, res_ty_args) <- tcResultType tycon tc_tvs res_ty
+ ; let
+ con_tvs = case res_ty of
+ ResTyH98 -> tc_tvs ++ tvs'
+ ResTyGADT _ -> tryVanilla tvs' res_ty_args
+
+ -- Vanilla iff result type matches the quantified vars exactly,
+ -- and there is no existential context
+ -- Must check the context too because of implicit params; e.g.
+ -- data T = (?x::Int) => MkT Int
+ is_vanilla = res_ty_args `tcEqTypes` mkTyVarTys con_tvs
+ && null (unLoc ctxt)
+
+ 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)
+ con_tvs ctxt' arg_tys
+ data_tc res_ty_args }
+ -- 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.
+
+ ; case details of
+ PrefixCon btys -> tc_datacon False [] btys
+ InfixCon bty1 bty2 -> tc_datacon True [] [bty1,bty2]
+ RecCon fields -> tc_datacon False field_names btys
+ where
+ (field_names, btys) = unzip fields
+
+ }
+
+tcResultType :: TyCon -> [TyVar] -> ResType Name -> TcM (TyCon, [TcType])
+tcResultType tycon tvs ResTyH98 = return (tycon, mkTyVarTys tvs)
+tcResultType _ _ (ResTyGADT res_ty) = tcLHsConResTy res_ty
+
+tryVanilla :: [TyVar] -> [TcType] -> [TyVar]
+-- (tryVanilla tvs tys) returns a permutation of tvs.
+-- It tries to re-order the tvs so that it exactly
+-- matches the [Type], if that is possible
+tryVanilla tvs (ty:tys) | Just tv <- tcGetTyVar_maybe ty -- The type is a tyvar
+ , tv `elem` tvs -- That tyvar is in the list
+ = tv : tryVanilla (delete tv tvs) tys
+tryVanilla tvs tys = tvs -- Fall through case
+
+
+-------------------
+argStrictness :: Bool -- True <=> -funbox-strict_fields
+ -> TyCon -> [HsBang]
+ -> [TcType] -> [StrictnessMark]
+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
+-- (ii) The field is marked '!', and the -funbox-strict-fields flag is on.
+
+chooseBoxingStrategy :: Bool -> TyCon -> TcType -> HsBang -> StrictnessMark
+chooseBoxingStrategy unbox_strict_fields tycon arg_ty bang
+ = case bang of
+ HsNoBang -> NotMarkedStrict
+ HsStrict | unbox_strict_fields && can_unbox -> MarkedUnboxed
+ HsUnbox | can_unbox -> MarkedUnboxed
+ other -> MarkedStrict
where
- (tycon_name, _, _, _) = getClassDeclSysNames name_list
- clas = mkClass class_name tyvars fds
- sc_theta sc_sel_ids op_items
- tycon
-
- tycon = mkClassTyCon tycon_name class_kind tyvars
- argvrcs dict_con
- clas -- Yes! It's a dictionary
- flavour
- is_rec
- -- A class can be recursive, and in the case of newtypes
- -- this matters. For example
- -- class C a where { op :: C b => a -> b -> Int }
- -- Because C has only one operation, it is represented by
- -- a newtype, and it should be a *recursive* newtype.
- -- [If we don't make it a recursive newtype, we'll expand the
- -- newtype like a synonym, but that will lead toan inifinite type
-
- ClassDetails sc_theta sc_sel_ids op_items dict_con = lookupNameEnv_NF rec_details class_name
-
- class_kind = lookupNameEnv_NF kenv class_name
- tyvars = mkTyClTyVars class_kind tyvar_names
- argvrcs = lookupWithDefaultFM rec_vrcs bogusVrcs tycon
-
- flavour = case dataConOrigArgTys dict_con of
- -- The tyvars in the datacon are the same as in the class
- [rep_ty] -> NewTyCon rep_ty
- other -> DataTyCon
-
- -- We can find the functional dependencies right away,
- -- and it is vital to do so. Why? Because in the next pass
- -- we check for ambiguity in all the type signatures, and we
- -- need the functional dependcies to be done by then
- fds = [(map lookup xs, map lookup ys) | (xs,ys) <- fundeps]
- tyvar_env = mkNameEnv [(varName tv, tv) | tv <- tyvars]
- lookup = lookupNameEnv_NF tyvar_env
-
-bogusVrcs = panic "Bogus tycon arg variances"
-\end{code}
-
-\begin{code}
-mkNewTyConRep :: TyCon -- The original type constructor
- -> Type -- Chosen representation type
--- Find the representation type for this newtype TyCon
--- See notes on newypes in types/TypeRep about newtypes.
-mkNewTyConRep tc = head (dataConOrigArgTys (head (tyConDataCons tc)))
+ can_unbox = case splitTyConApp_maybe arg_ty of
+ Nothing -> False
+ Just (arg_tycon, _) -> not (isRecursiveTyCon tycon) &&
+ isProductTyCon arg_tycon
\end{code}
-
%************************************************************************
%* *
\subsection{Dependency analysis}
%* *
%************************************************************************
-Dependency analysis
-~~~~~~~~~~~~~~~~~~~
+Validity checking is done once the mutually-recursive knot has been
+tied, so we can look at things freely.
+
\begin{code}
-sortByDependency :: [RenamedTyClDecl] -> TcM [SCC RenamedTyClDecl]
-sortByDependency decls
- = let -- CHECK FOR CLASS CYCLES
- cls_sccs = stronglyConnComp (mapMaybe mkClassEdges tycl_decls)
- cls_cycles = [ decls | CyclicSCC decls <- cls_sccs]
- in
- checkTc (null cls_cycles) (classCycleErr cls_cycles) `thenTc_`
-
- let -- CHECK FOR SYNONYM CYCLES
- syn_sccs = stronglyConnComp (filter is_syn_decl edges)
- syn_cycles = [ decls | CyclicSCC decls <- syn_sccs]
-
- in
- checkTc (null syn_cycles) (typeCycleErr syn_cycles) `thenTc_`
-
- -- DO THE MAIN DEPENDENCY ANALYSIS
- let
- decl_sccs = stronglyConnComp edges
- in
- returnTc decl_sccs
+checkCycleErrs :: [LTyClDecl Name] -> TcM ()
+checkCycleErrs tyclss
+ | null cls_cycles
+ = return ()
+ | otherwise
+ = do { mappM_ recClsErr cls_cycles
+ ; failM } -- Give up now, because later checkValidTyCl
+ -- will loop if the synonym is recursive
where
- tycl_decls = filter (not . isIfaceSigDecl) decls
- edges = map mkEdges tycl_decls
-
- is_syn_decl (d, _, _) = isSynDecl d
-\end{code}
+ cls_cycles = calcClassCycles tyclss
+
+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 <- tcLookupLocatedGlobal (tcdLName decl)
+ ; traceTc (text "Validity of" <+> ppr thing)
+ ; case thing of
+ ATyCon tc -> checkValidTyCon tc
+ AClass cl -> checkValidClass cl
+ ; traceTc (text "Done validity of" <+> ppr thing)
+ }
+
+-------------------------
+-- For data types declared with record syntax, we require
+-- that each constructor that has a field 'f'
+-- (a) has the same result type
+-- (b) has the same type for 'f'
+-- module alpha conversion of the quantified type variables
+-- of the constructor.
+
+checkValidTyCon :: TyCon -> TcM ()
+checkValidTyCon tc
+ | isSynTyCon tc
+ = checkValidType syn_ctxt syn_rhs
+ | otherwise
+ = -- Check the context on the data decl
+ checkValidTheta (DataTyCtxt name) (tyConStupidTheta tc) `thenM_`
+
+ -- Check arg types of data constructors
+ mappM_ (checkValidDataCon tc) data_cons `thenM_`
-Edges in Type/Class decls
-~~~~~~~~~~~~~~~~~~~~~~~~~
+ -- Check that fields with the same name share a type
+ mappM_ check_fields groups
-\begin{code}
-tyClDeclFTVs :: RenamedTyClDecl -> [Name]
- -- Find the free non-tyvar vars
-tyClDeclFTVs d = foldNameSet add [] (tyClDeclFVs d)
- where
- add n fvs | isTyVarName n = fvs
- | otherwise = n : fvs
+ where
+ syn_ctxt = TySynCtxt name
+ name = tyConName tc
+ syn_rhs = synTyConRhs tc
+ data_cons = tyConDataCons tc
+
+ groups = equivClasses cmp_fld (concatMap get_fields data_cons)
+ cmp_fld (f1,_) (f2,_) = f1 `compare` f2
+ get_fields con = dataConFieldLabels con `zip` repeat con
+ -- dataConFieldLabels may return the empty list, which is fine
+
+ -- XXX - autrijus - Make this far more complex to acommodate
+ -- for different return types. Add res_ty to the mix,
+ -- comparing them in two steps, all for good error messages.
+ -- Plan: Use Unify.tcMatchTys to compare the first candidate's
+ -- result type against other candidates' types (check bothways).
+ -- If they magically agrees, take the substitution and
+ -- apply them to the latter ones, and see if they match perfectly.
+ -- check_fields fields@((first_field_label, field_ty) : other_fields)
+ check_fields fields@((label, con1) : other_fields)
+ -- These fields all have the same name, but are from
+ -- different constructors in the data type
+ = recoverM (return ()) $ mapM_ checkOne other_fields
+ -- 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
+ where
+ tvs1 = mkVarSet (dataConTyVars con1)
+ res1 = dataConResTys con1
+ fty1 = dataConFieldType con1 label
+
+ checkOne (_, con2) -- Do it bothways to ensure they are structurally identical
+ = do { checkFieldCompat label con1 con2 tvs1 res1 res2 fty1 fty2
+ ; checkFieldCompat label con2 con1 tvs2 res2 res1 fty2 fty1 }
+ where
+ tvs2 = mkVarSet (dataConTyVars con2)
+ res2 = dataConResTys con2
+ fty2 = dataConFieldType con2 label
+
+checkFieldCompat fld con1 con2 tvs1 res1 res2 fty1 fty2
+ = do { checkTc (isJust mb_subst1) (resultTypeMisMatch fld con1 con2)
+ ; checkTc (isJust mb_subst2) (fieldTypeMisMatch fld con1 con2) }
+ where
+ mb_subst1 = tcMatchTys tvs1 res1 res2
+ mb_subst2 = tcMatchTyX tvs1 (expectJust "checkFieldCompat" mb_subst1) fty1 fty2
+
+-------------------------------
+checkValidDataCon :: TyCon -> DataCon -> TcM ()
+checkValidDataCon tc con
+ = setSrcSpan (srcLocSpan (getSrcLoc 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)
+ --
+ -- 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)
+-- (tvs, ex_theta, _, _, _) = dataConSig con
-----------------------------------------------------
--- mk_cls_edges looks only at the context of class decls
--- Its used when we are figuring out if there's a cycle in the
--- superclass hierarchy
-mkClassEdges :: RenamedTyClDecl -> Maybe (RenamedTyClDecl, Name, [Name])
+-------------------------------
+checkValidClass :: Class -> TcM ()
+checkValidClass cls
+ = do { -- CHECK ARITY 1 FOR HASKELL 1.4
+ gla_exts <- doptM Opt_GlasgowExts
-mkClassEdges decl@(ClassDecl {tcdCtxt = ctxt, tcdName = name}) = Just (decl, name, [c | HsClassP c _ <- ctxt])
-mkClassEdges other_decl = Nothing
+ -- Check that the class is unary, unless GlaExs
+ ; checkTc (notNull tyvars) (nullaryClassErr cls)
+ ; checkTc (gla_exts || unary) (classArityErr cls)
-mkEdges :: RenamedTyClDecl -> (RenamedTyClDecl, Name, [Name])
-mkEdges decl = (decl, tyClDeclName decl, tyClDeclFTVs decl)
-\end{code}
+ -- Check the super-classes
+ ; checkValidTheta (ClassSCCtxt (className cls)) theta
+ -- Check the class operations
+ ; mappM_ (check_op gla_exts) op_stuff
-%************************************************************************
-%* *
-\subsection{Error management
-%* *
-%************************************************************************
+ -- Check that if the class has generic methods, then the
+ -- class has only one parameter. We can't do generic
+ -- multi-parameter type classes!
+ ; checkTc (unary || no_generics) (genericMultiParamErr cls)
+ }
+ where
+ (tyvars, theta, _, op_stuff) = classBigSig cls
+ unary = isSingleton tyvars
+ no_generics = null [() | (_, GenDefMeth) <- op_stuff]
+
+ check_op gla_exts (sel_id, dm)
+ = 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
+
+ -- 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 tau)
+ (badGenericMethodType op_name op_ty)
+ }
+ where
+ op_name = idName sel_id
+ op_ty = idType sel_id
+ (_,theta1,tau1) = tcSplitSigmaTy op_ty
+ (_,theta2,tau2) = tcSplitSigmaTy tau1
+ (theta,tau) | gla_exts = (theta1 ++ theta2, tau2)
+ | otherwise = (theta1, mkPhiTy (tail theta1) tau1)
+ -- Ugh! The function might have a type like
+ -- op :: forall a. C a => forall b. (Eq b, Eq a) => tau2
+ -- With -fglasgow-exts, we want to allow this, even though the inner
+ -- forall has an (Eq a) constraint. Whereas in general, each constraint
+ -- in the context of a for-all must mention at least one quantified
+ -- type variable. What a mess!
+
+
+---------------------------------------------------------------------
+resultTypeMisMatch field_name con1 con2
+ = vcat [sep [ptext SLIT("Constructors") <+> ppr con1 <+> ptext SLIT("and") <+> ppr con2,
+ ptext SLIT("have a common field") <+> quotes (ppr field_name) <> comma],
+ nest 2 $ ptext SLIT("but have different result types")]
+fieldTypeMisMatch field_name con1 con2
+ = sep [ptext SLIT("Constructors") <+> ppr con1 <+> ptext SLIT("and") <+> ppr con2,
+ ptext SLIT("give different types for field"), quotes (ppr field_name)]
+
+dataConCtxt con = ptext SLIT("In the definition of data constructor") <+> quotes (ppr con)
+
+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)
+
+classArityErr 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")
+
+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, lists, and tuples")])
+
+recSynErr syn_decls
+ = setSrcSpan (getLoc (head sorted_decls)) $
+ addErr (sep [ptext SLIT("Cycle in type synonym declarations:"),
+ nest 2 (vcat (map ppr_decl sorted_decls))])
+ where
+ sorted_decls = sortLocated syn_decls
+ ppr_decl (L loc decl) = ppr loc <> colon <+> ppr decl
-\begin{code}
-typeCycleErr, classCycleErr :: [[RenamedTyClDecl]] -> Message
+recClsErr cls_decls
+ = setSrcSpan (getLoc (head sorted_decls)) $
+ addErr (sep [ptext SLIT("Cycle in class declarations (via superclasses):"),
+ 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
-typeCycleErr syn_cycles
- = vcat (map (pp_cycle "Cycle in type declarations:") syn_cycles)
+badDataConTyCon 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"))
-classCycleErr cls_cycles
- = vcat (map (pp_cycle "Cycle in class declarations:") cls_cycles)
+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")) ]
-pp_cycle str decls
- = hang (text str)
- 4 (vcat (map pp_decl decls))
- where
- pp_decl decl
- = hsep [quotes (ppr name), ptext SLIT("at"), ppr (getSrcLoc name)]
- where
- name = tyClDeclName decl
+newtypeConError tycon n
+ = sep [ptext SLIT("A newtype must have exactly one constructor,"),
+ nest 2 $ ptext SLIT("but") <+> quotes (ppr tycon) <+> ptext SLIT("has") <+> speakN n ]
+
+newtypeExError con
+ = sep [ptext SLIT("A newtype constructor cannot have an existential context,"),
+ nest 2 $ ptext SLIT("but") <+> quotes (ppr con) <+> ptext SLIT("does")]
+
+newtypeFieldErr con_name n_flds
+ = sep [ptext SLIT("The constructor of a newtype must have exactly one field"),
+ nest 2 $ ptext SLIT("but") <+> quotes (ppr con_name) <+> ptext SLIT("has") <+> speakN n_flds]
+
+emptyConDeclsErr tycon
+ = sep [quotes (ppr tycon) <+> ptext SLIT("has no constructors"),
+ nest 2 $ ptext SLIT("(-fglasgow-exts permits this)")]
+badBootClassDeclErr = ptext SLIT("Illegal class declaration in hs-boot file")
\end{code}
projects / ghc-hetmet.git / blobdiff