X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FTcTyClsDecls.lhs;h=7997de58a092541c35cd734a547af75fd36e0401;hb=b0604aad2c311d8713c2497afa6373bd938d501b;hp=030e7102133bf430886267399f954ef2485d4157;hpb=ff755dd9a0a0ad2f106c323852553ea247f16141;p=ghc-hetmet.git diff --git a/ghc/compiler/typecheck/TcTyClsDecls.lhs b/ghc/compiler/typecheck/TcTyClsDecls.lhs index 030e710..7997de5 100644 --- a/ghc/compiler/typecheck/TcTyClsDecls.lhs +++ b/ghc/compiler/typecheck/TcTyClsDecls.lhs @@ -10,158 +10,232 @@ module TcTyClsDecls ( #include "HsVersions.h" -import HsSyn ( HsDecl(..), TyClDecl(..), - HsType(..), HsTyVarBndr, - ConDecl(..), ConDetails(..), BangType(..), - Sig(..), HsPred(..), HsTupCon(..), - tyClDeclName, isClassDecl, isSynDecl +import CmdLineOpts ( DynFlags, DynFlag(..), dopt ) +import HsSyn ( TyClDecl(..), + ConDecl(..), Sig(..), HsPred(..), + tyClDeclName, hsTyVarNames, tyClDeclTyVars, + isIfaceSigDecl, isClassDecl, isSynDecl, isClassOpSig ) -import RnHsSyn ( RenamedHsDecl, RenamedTyClDecl, listTyCon_name ) -import BasicTypes ( RecFlag(..), NewOrData(..), Arity ) +import RnHsSyn ( RenamedTyClDecl, tyClDeclFVs ) +import BasicTypes ( RecFlag(..), NewOrData(..) ) +import HscTypes ( implicitTyThingIds ) +import Module ( Module ) import TcMonad -import TcClassDcl ( kcClassDecl, tcClassDecl1 ) -import TcEnv ( ValueEnv, TcTyThing(..), - tcExtendTypeEnv, getEnvAllTyCons +import TcEnv ( TcEnv, RecTcEnv, TcTyThing(..), TyThing(..), TyThingDetails(..), + tcExtendKindEnv, tcLookup, tcExtendGlobalEnv, tcExtendGlobalValEnv, + isLocalThing ) +import TcTyDecls ( tcTyDecl, kcConDetails, checkValidTyCon ) +import TcClassDcl ( tcClassDecl1, checkValidClass ) +import TcInstDcls ( tcAddDeclCtxt ) +import TcMonoType ( kcHsTyVars, kcHsType, kcHsLiftedSigType, kcHsContext, mkTyClTyVars ) +import TcMType ( unifyKind, newKindVar, zonkKindEnv ) +import TcType ( Type, Kind, mkArrowKind, liftedTypeKind, zipFunTys ) +import Type ( splitTyConApp_maybe ) +import Variance ( calcTyConArgVrcs ) +import Class ( Class, mkClass, classTyCon ) +import TyCon ( TyCon, ArgVrcs, AlgTyConFlavour(..), + tyConKind, tyConTyVars, tyConDataCons, isNewTyCon, + mkSynTyCon, mkAlgTyCon, mkClassTyCon, mkForeignTyCon, ) -import TcTyDecls ( tcTyDecl, kcTyDecl ) -import TcMonoType ( kcHsTyVar ) -import TcType ( TcKind, newKindVar, newKindVars, kindToTcKind, zonkTcKindToKind ) - -import Type ( mkArrowKind, boxedTypeKind ) - +import TysWiredIn ( unitTy ) +import Subst ( substTyWith ) +import DataCon ( dataConOrigArgTys ) +import Var ( varName ) import FiniteMap -import Bag import Digraph ( stronglyConnComp, SCC(..) ) -import Name ( Name, NamedThing(..), getSrcLoc, isTvOcc, nameOccName ) +import Name ( Name, getSrcLoc, isTyVarName ) +import NameEnv +import NameSet import Outputable -import Maybes ( mapMaybe, catMaybes, expectJust ) -import UniqSet ( UniqSet, emptyUniqSet, - unitUniqSet, unionUniqSets, - unionManyUniqSets, uniqSetToList ) +import Maybes ( mapMaybe ) import ErrUtils ( Message ) -import TyCon ( TyCon, ArgVrcs ) -import Variance ( calcTyConArgVrcs ) -import Unique ( Unique, Uniquable(..) ) -import UniqFM ( listToUFM, lookupUFM ) +import HsDecls ( getClassDeclSysNames ) +import Generics ( mkTyConGenInfo ) \end{code} + +%************************************************************************ +%* * +\subsection{Type checking for type and class declarations} +%* * +%************************************************************************ + The main function ~~~~~~~~~~~~~~~~~ \begin{code} -tcTyAndClassDecls :: ValueEnv -- Knot tying stuff - -> [RenamedHsDecl] - -> TcM s TcEnv +tcTyAndClassDecls :: RecTcEnv -- Knot tying stuff + -> Module -- Current module + -> [RenamedTyClDecl] + -> TcM TcEnv -tcTyAndClassDecls unf_env decls +tcTyAndClassDecls unf_env this_mod decls = sortByDependency decls `thenTc` \ groups -> - tcGroups unf_env groups + tcGroups unf_env this_mod groups -tcGroups unf_env [] +tcGroups unf_env this_mod [] = tcGetEnv `thenNF_Tc` \ env -> returnTc env -tcGroups unf_env (group:groups) - = tcGroup unf_env group `thenTc` \ env -> +tcGroups unf_env this_mod (group:groups) + = tcGroup unf_env this_mod group `thenTc` \ env -> tcSetEnv env $ - tcGroups unf_env groups + tcGroups unf_env this_mod groups \end{code} Dealing with a group ~~~~~~~~~~~~~~~~~~~~ +Consider a mutually-recursive group, binding +a type constructor T and a class C. + +Step 1: getInitialKind + Construct a KindEnv by binding T and C to a kind variable + +Step 2: kcTyClDecl + In that environment, do a kind check + +Step 3: Zonk the kinds + +Step 4: buildTyConOrClass + Construct an environment binding T to a TyCon and C to a Class. + a) Their kinds comes from zonking the relevant kind variable + b) Their arity (for synonyms) comes direct from the decl + c) The funcional dependencies come from the decl + d) The rest comes a knot-tied binding of T and C, returned from Step 4 + e) The variances of the tycons in the group is calculated from + the knot-tied stuff + +Step 5: tcTyClDecl1 + In this environment, walk over the decls, constructing the TyCons and Classes. + This uses in a strict way items (a)-(c) above, which is why they must + be constructed in Step 4. Feed the results back to Step 4. + For this step, pass the is-recursive flag as the wimp-out flag + to tcTyClDecl1. + + +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 -The knot-tying parameters: @rec_tyclss@ is an alist mapping @Name@s to -@TcTyThing@s. @rec_vrcs@ is a finite map from @Name@s to @ArgVrcs@s. +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 :: ValueEnv -> SCC RenamedTyClDecl -> TcM s TcEnv -tcGroup unf_env scc - = -- Do kind checking - mapNF_Tc getTyBinding1 decls `thenNF_Tc` \ ty_env_stuff1 -> - tcExtendTypeEnv ty_env_stuff1 (mapTc kcDecl decls) `thenTc_` +tcGroup :: RecTcEnv -> Module -> SCC RenamedTyClDecl -> TcM TcEnv +tcGroup unf_env this_mod 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 (ppr (map fst ty_env_stuff1)) `thenTc_` - fixTc ( \ ~(rec_tyclss, _) -> - let - rec_env = listToUFM rec_tyclss - rec_tycons = getEnvAllTyCons rec_tyclss - rec_vrcs = calcTyConArgVrcs rec_tycons + 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 - - -- Do type checking - mapNF_Tc (getTyBinding2 rec_env) ty_env_stuff1 `thenNF_Tc` \ ty_env_stuff2 -> - tcExtendTypeEnv ty_env_stuff2 $ - mapTc (tcDecl is_rec_group unf_env rec_vrcs) decls `thenTc` \ tyclss -> - - tcGetEnv `thenTc` \ env -> - returnTc (tyclss, env) - ) `thenTc` \ (_, env) -> --- traceTc (text "done" <+> ppr (map fst ty_env_stuff1)) `thenTc_` + -- Step 5 + -- Extend the environment with the final + -- TyCons/Classes and check the decls + tcExtendGlobalEnv all_tyclss $ + mapTc (tcTyClDecl1 unf_env) decls `thenTc` \ tycls_details -> + + -- Step 6 + -- Extend the environment with implicit Ids + tcExtendGlobalValEnv (implicitTyThingIds all_tyclss) $ + + -- Return results + tcGetEnv `thenNF_Tc` \ env -> + returnTc (tycls_details, tyclss, env) + ) `thenTc` \ (_, tyclss, env) -> + + + -- Step 7: Check validity + traceTc (text "ready for validity check") `thenTc_` + tcSetEnv env ( + mapTc_ (checkValidTyCl this_mod) decls + ) `thenTc_` + traceTc (text "done") `thenTc_` + returnTc env + where - is_rec_group = case scc of - AcyclicSCC _ -> NonRecursive - CyclicSCC _ -> Recursive + is_rec = case scc of + AcyclicSCC _ -> NonRecursive + CyclicSCC _ -> Recursive decls = case scc of AcyclicSCC decl -> [decl] CyclicSCC decls -> decls -\end{code} - -Dealing with one decl -~~~~~~~~~~~~~~~~~~~~~ -\begin{code} -kcDecl decl - = tcAddDeclCtxt decl $ - if isClassDecl decl then - kcClassDecl decl - else - kcTyDecl decl -tcDecl :: RecFlag -- True => recursive group - -> ValueEnv -> FiniteMap Name ArgVrcs - -> RenamedTyClDecl -> TcM s (Name, TcTyThing) +tcTyClDecl1 unf_env decl + | isClassDecl decl = tcAddDeclCtxt decl (tcClassDecl1 unf_env decl) + | otherwise = tcAddDeclCtxt decl (tcTyDecl unf_env decl) -tcDecl is_rec_group unf_env vrcs_env decl - = tcAddDeclCtxt decl $ - if isClassDecl decl then - tcClassDecl1 unf_env vrcs_env decl +checkValidTyCl this_mod decl + = tcLookup (tcdName decl) `thenNF_Tc` \ (AGlobal thing) -> + if not (isLocalThing this_mod thing) then + -- Don't bother to check validity for non-local things + returnTc () else - tcTyDecl is_rec_group vrcs_env decl - - -tcAddDeclCtxt decl thing_inside - = tcAddSrcLoc loc $ - tcAddErrCtxt ctxt $ - thing_inside - where - (name, loc, thing) - = case decl of - (ClassDecl _ name _ _ _ _ _ _ _ _ _ loc) -> (name, loc, "class") - (TySynonym name _ _ loc) -> (name, loc, "type synonym") - (TyData NewType _ name _ _ _ _ _ loc) -> (name, loc, "data type") - (TyData DataType _ name _ _ _ _ _ loc) -> (name, loc, "newtype") - - ctxt = hsep [ptext SLIT("In the"), text thing, - ptext SLIT("declaration for"), quotes (ppr name)] + tcAddDeclCtxt decl $ + case thing of + ATyCon tc -> checkValidTyCon tc + AClass cl -> checkValidClass cl \end{code} -getTyBinders -~~~~~~~~~~~ -Extract *binding* names from type and class decls. Type variables are -bound in type, data, newtype and class declarations, - *and* the polytypes in the class op sigs. - *and* the existentially quantified contexts in datacon decls +%************************************************************************ +%* * +\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 +\end{code} -Why do we need to grab all these type variables at once, including -those locally-quantified type variables in class op signatures? - [Incidentally, this only works because the names are all unique by now.] +%************************************************************************ +%* * +\subsection{Step 2: Kind checking} +%* * +%************************************************************************ -Because we can only commit to the final kind of a type variable when -we've completed the mutually recursive group. For example: +We need to kind check all types in the mutually recursive group +before we know the kind of the type variables. For example: class C a where op :: D b => a -> b -> b @@ -173,37 +247,189 @@ Here, the kind of the locally-polymorphic type variable "b" 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. - [April 00: looks as if we've dropped this subtlety; I'm not sure when] +\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 () + +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 + 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) + where + kc_sig (ClassOpSig _ _ op_ty loc) = kcHsLiftedSigType op_ty + +kcTyClDeclBody :: RenamedTyClDecl -> (Kind -> 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 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) +\end{code} + + + +%************************************************************************ +%* * +\subsection{Step 4: Building the tycon/class} +%* * +%************************************************************************ \begin{code} -getTyBinding1 :: RenamedTyClDecl -> NF_TcM s (Name, (TcKind, TcTyThing)) -getTyBinding1 (TySynonym name tyvars _ _) - = mapNF_Tc kcHsTyVar tyvars `thenNF_Tc` \ arg_kinds -> - newKindVar `thenNF_Tc` \ result_kind -> - returnNF_Tc (name, (foldr mkArrowKind result_kind arg_kinds, - ASynTyCon (pprPanic "ATyCon: syn" (ppr name)) (length tyvars))) - -getTyBinding1 (TyData _ _ name tyvars _ _ _ _ _) - = mapNF_Tc kcHsTyVar tyvars `thenNF_Tc` \ arg_kinds -> - returnNF_Tc (name, (foldr mkArrowKind boxedTypeKind arg_kinds, - ADataTyCon (error "ATyCon: data"))) - -getTyBinding1 (ClassDecl _ name tyvars _ _ _ _ _ _ _ _ _) - = mapNF_Tc kcHsTyVar tyvars `thenNF_Tc` \ arg_kinds -> - returnNF_Tc (name, (foldr mkArrowKind boxedTypeKind arg_kinds, - AClass (pprPanic "AClass" (ppr name)) (length tyvars))) - --- Zonk the kind to its final form, and lookup the --- recursive tycon/class -getTyBinding2 rec_env (name, (tc_kind, thing)) - = zonkTcKindToKind tc_kind `thenNF_Tc` \ kind -> - returnNF_Tc (name, (kind, mk_thing thing (lookupUFM rec_env name))) +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 + 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 where - mk_thing (ADataTyCon _) ~(Just (ADataTyCon tc)) = ADataTyCon tc - mk_thing (ASynTyCon _ arity) ~(Just (ASynTyCon tc _)) = ASynTyCon tc arity - mk_thing (AClass _ arity) ~(Just (AClass cls _)) = AClass cls arity + 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 + 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 + -- (guaranteed not to be another newtype) + +-- Find the representation type for this newtype TyCon +-- +-- The non-recursive newtypes are easy, because they look transparent +-- to splitTyConApp_maybe, but recursive ones really are represented as +-- TyConApps (see TypeRep). +-- +-- The trick is to to deal correctly with recursive newtypes +-- such as newtype T = MkT T + +mkNewTyConRep tc + = go [] tc + where + -- Invariant: tc is a NewTyCon + -- tcs have been seen before + go tcs tc + | tc `elem` tcs = unitTy + | otherwise + = let + rep_ty = head (dataConOrigArgTys (head (tyConDataCons tc))) + in + case splitTyConApp_maybe rep_ty of + Nothing -> rep_ty + Just (tc', tys) | not (isNewTyCon tc') -> rep_ty + | otherwise -> go1 (tc:tcs) tc' tys + + go1 tcs tc tys = substTyWith (tyConTyVars tc) tys (go tcs tc) +\end{code} %************************************************************************ %* * @@ -214,10 +440,10 @@ getTyBinding2 rec_env (name, (tc_kind, thing)) Dependency analysis ~~~~~~~~~~~~~~~~~~~ \begin{code} -sortByDependency :: [RenamedHsDecl] -> TcM s [SCC RenamedTyClDecl] +sortByDependency :: [RenamedTyClDecl] -> TcM [SCC RenamedTyClDecl] sortByDependency decls = let -- CHECK FOR CLASS CYCLES - cls_sccs = stronglyConnComp (mapMaybe mk_cls_edges tycl_decls) + cls_sccs = stronglyConnComp (mapMaybe mkClassEdges tycl_decls) cls_cycles = [ decls | CyclicSCC decls <- cls_sccs] in checkTc (null cls_cycles) (classCycleErr cls_cycles) `thenTc_` @@ -235,8 +461,8 @@ sortByDependency decls in returnTc decl_sccs where - tycl_decls = [d | TyClD d <- decls] - edges = map mk_edges tycl_decls + tycl_decls = filter (not . isIfaceSigDecl) decls + edges = map mkEdges tycl_decls is_syn_decl (d, _, _) = isSynDecl d \end{code} @@ -245,91 +471,34 @@ Edges in Type/Class decls ~~~~~~~~~~~~~~~~~~~~~~~~~ \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 + ---------------------------------------------------- -- 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 -mk_cls_edges :: RenamedTyClDecl -> Maybe (RenamedTyClDecl, Unique, [Unique]) - -mk_cls_edges decl@(ClassDecl ctxt name _ _ _ _ _ _ _ _ _ _) - = Just (decl, getUnique name, map getUnique (catMaybes (map get_clas ctxt))) -mk_cls_edges other_decl - = Nothing - ----------------------------------------------------- -mk_edges :: RenamedTyClDecl -> (RenamedTyClDecl, Unique, [Unique]) - -mk_edges decl@(TyData _ ctxt name _ condecls _ derivs _ _) - = (decl, getUnique name, uniqSetToList (get_ctxt ctxt `unionUniqSets` - get_cons condecls `unionUniqSets` - get_deriv derivs)) - -mk_edges decl@(TySynonym name _ rhs _) - = (decl, getUnique name, uniqSetToList (get_ty rhs)) - -mk_edges decl@(ClassDecl ctxt name _ _ sigs _ _ _ _ _ _ _) - = (decl, getUnique name, uniqSetToList (get_ctxt ctxt `unionUniqSets` - get_sigs sigs)) - +mkClassEdges :: RenamedTyClDecl -> Maybe (RenamedTyClDecl, Name, [Name]) ----------------------------------------------------- -get_ctxt ctxt = unionManyUniqSets (map set_name (catMaybes (map get_clas ctxt))) -get_clas (HsPClass clas _) = Just clas -get_clas _ = Nothing - ----------------------------------------------------- -get_deriv Nothing = emptyUniqSet -get_deriv (Just clss) = unionManyUniqSets (map set_name clss) - ----------------------------------------------------- -get_cons cons = unionManyUniqSets (map get_con cons) - ----------------------------------------------------- -get_con (ConDecl _ _ _ ctxt details _) - = get_ctxt ctxt `unionUniqSets` get_con_details details - ----------------------------------------------------- -get_con_details (VanillaCon btys) = unionManyUniqSets (map get_bty btys) -get_con_details (InfixCon bty1 bty2) = unionUniqSets (get_bty bty1) (get_bty bty2) -get_con_details (NewCon ty _) = get_ty ty -get_con_details (RecCon nbtys) = unionManyUniqSets (map (get_bty.snd) nbtys) - ----------------------------------------------------- -get_bty (Banged ty) = get_ty ty -get_bty (Unbanged ty) = get_ty ty -get_bty (Unpacked ty) = get_ty ty - ----------------------------------------------------- -get_ty (HsTyVar name) | isTvOcc (nameOccName name) = emptyUniqSet - | otherwise = set_name name -get_ty (HsAppTy ty1 ty2) = unionUniqSets (get_ty ty1) (get_ty ty2) -get_ty (HsFunTy ty1 ty2) = unionUniqSets (get_ty ty1) (get_ty ty2) -get_ty (HsListTy ty) = set_name listTyCon_name `unionUniqSets` get_ty ty -get_ty (HsTupleTy (HsTupCon n _) tys) = set_name n `unionUniqSets` get_tys tys -get_ty (HsUsgTy _ ty) = get_ty ty -get_ty (HsUsgForAllTy _ ty) = get_ty ty -get_ty (HsForAllTy _ ctxt mty) = get_ctxt ctxt `unionUniqSets` get_ty mty -get_ty (HsPredTy (HsPClass name _)) = set_name name -get_ty (HsPredTy (HsPIParam _ _)) = emptyUniqSet -- I think - ----------------------------------------------------- -get_tys tys = unionManyUniqSets (map get_ty tys) +mkClassEdges decl@(ClassDecl {tcdCtxt = ctxt, tcdName = name}) = Just (decl, name, [c | HsClassP c _ <- ctxt]) +mkClassEdges other_decl = Nothing ----------------------------------------------------- -get_sigs sigs - = unionManyUniqSets (map get_sig sigs) - where - get_sig (ClassOpSig _ _ _ ty _) = get_ty ty - get_sig (FixSig _) = emptyUniqSet - get_sig other = panic "TcTyClsDecls:get_sig" - ----------------------------------------------------- -set_name name = unitUniqSet (getUnique name) -set_to_bag set = listToBag (uniqSetToList set) +mkEdges :: RenamedTyClDecl -> (RenamedTyClDecl, Name, [Name]) +mkEdges decl = (decl, tyClDeclName decl, tyClDeclFTVs decl) \end{code} +%************************************************************************ +%* * +\subsection{Error management +%* * +%************************************************************************ + \begin{code} typeCycleErr, classCycleErr :: [[RenamedTyClDecl]] -> Message @@ -347,4 +516,5 @@ pp_cycle str decls = hsep [quotes (ppr name), ptext SLIT("at"), ppr (getSrcLoc name)] where name = tyClDeclName decl + \end{code}