#include "HsVersions.h"
-import HsSyn ( HsDecl(..), TyClDecl(..),
- HsType(..), HsTyVar,
- ConDecl(..), ConDetails(..), BangType(..),
- Sig(..),
- tyClDeclName, isClassDecl, isSynDecl
+import CmdLineOpts ( DynFlags, DynFlag(..), dopt )
+import HsSyn ( TyClDecl(..),
+ ConDecl(..), Sig(..), HsPred(..),
+ tyClDeclName, hsTyVarNames,
+ isIfaceSigDecl, isClassDecl, isSynDecl, isClassOpSig
)
-import RnHsSyn ( RenamedHsDecl, RenamedTyClDecl, listTyCon_name, tupleTyCon_name )
-import BasicTypes ( RecFlag(..), NewOrData(..), Arity )
+import RnHsSyn ( RenamedTyClDecl, tyClDeclFVs )
+import BasicTypes ( RecFlag(..), NewOrData(..), isRec )
+import HscTypes ( implicitTyThingIds )
import TcMonad
-import Inst ( InstanceMapper )
-import TcClassDcl ( kcClassDecl, tcClassDecl1 )
-import TcEnv ( ValueEnv, TcTyThing(..),
- tcExtendTypeEnv, getAllEnvTyCons
- )
-import TcTyDecls ( tcTyDecl, kcTyDecl )
-import TcMonoType ( kcHsTyVar )
-import TcType ( TcKind, newKindVar, newKindVars, kindToTcKind, zonkTcKindToKind )
-
-import Type ( mkArrowKind, boxedTypeKind, mkDictTy )
- -- next two imports for usage stuff only
-import TyCon ( ArgVrcs, tyConKind, tyConArity, tyConDataCons, tyConTyVars,
- tyConArgVrcs_maybe, getSynTyConDefn, isSynTyCon, isAlgTyCon )
-import DataCon ( dataConRawArgTys, dataConSig )
-
-import Class ( Class, classBigSig )
-import Type ( Type(..), TyNote(..), tyVarsOfTypes )
-import Var ( TyVar, tyVarKind )
+import TcEnv ( TcEnv, RecTcEnv, TcTyThing(..), TyThing(..), TyThingDetails(..),
+ tcExtendKindEnv, tcLookup, tcExtendGlobalEnv, tcExtendGlobalValEnv )
+import TcTyDecls ( tcTyDecl1, kcConDetails, mkNewTyConRep )
+import TcClassDcl ( tcClassDecl1 )
+import TcMonoType ( kcHsTyVars, kcHsType, kcHsBoxedSigType, kcHsContext, mkTyClTyVars )
+import TcType ( TcKind, newKindVar, zonkKindEnv )
+
+import TcUnify ( unifyKind )
+import TcInstDcls ( tcAddDeclCtxt )
+import Type ( Kind, mkArrowKind, zipFunTys )
+import Variance ( calcTyConArgVrcs )
+import Class ( Class, mkClass, classTyCon )
+import TyCon ( TyCon, tyConKind, ArgVrcs, AlgTyConFlavour(..),
+ mkSynTyCon, mkAlgTyCon, mkClassTyCon )
+import DataCon ( isNullaryDataCon )
+import Var ( varName )
import FiniteMap
-import Bag
-import VarSet
import Digraph ( stronglyConnComp, SCC(..) )
-import Name ( Name, NamedThing(..), getSrcLoc, isTvOcc, nameOccName )
+import Name ( Name, getSrcLoc, isTyVarName )
+import Name ( NameEnv, mkNameEnv, lookupNameEnv_NF )
+import NameSet
import Outputable
-import Maybes ( mapMaybe, expectJust )
-import UniqSet ( UniqSet, emptyUniqSet,
- unitUniqSet, unionUniqSets,
- unionManyUniqSets, uniqSetToList )
+import Maybes ( mapMaybe )
import ErrUtils ( Message )
-import SrcLoc ( SrcLoc )
-import TyCon ( TyCon )
-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 -> InstanceMapper -- Knot tying stuff
- -> [RenamedHsDecl]
- -> TcM s TcEnv
+tcTyAndClassDecls :: RecTcEnv -- Knot tying stuff
+ -> [RenamedTyClDecl]
+ -> TcM TcEnv
-tcTyAndClassDecls unf_env inst_mapper decls
+tcTyAndClassDecls unf_env decls
= sortByDependency decls `thenTc` \ groups ->
- tcGroups unf_env inst_mapper groups
+ tcGroups unf_env groups
-tcGroups unf_env inst_mapper []
+tcGroups unf_env []
= tcGetEnv `thenNF_Tc` \ env ->
returnTc env
-tcGroups unf_env inst_mapper (group:groups)
- = tcGroup unf_env inst_mapper group `thenTc` \ env ->
- tcSetEnv env $
- tcGroups unf_env inst_mapper groups
+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
+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: 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 unboxed tuple, looking
+ through type synonyms properly. We can't do that in Step 5.
+
+Step 7: 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.
+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 -> InstanceMapper -> SCC RenamedTyClDecl -> TcM s TcEnv
-tcGroup unf_env inst_mapper scc
- = -- Do kind checking
- mapNF_Tc getTyBinding1 decls `thenNF_Tc` \ ty_env_stuff1 ->
- tcExtendTypeEnv ty_env_stuff1 (mapTc kcDecl decls) `thenTc_`
+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 (ppr (map fst ty_env_stuff1)) `thenTc_`
- fixTc ( \ ~(rec_tyclss, rec_vrcs, _) ->
- let
- rec_env = listToUFM rec_tyclss
+ 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 inst_mapper rec_vrcs) decls
- `thenTc` \ tyclss ->
-
- tcGetEnv `thenTc` \ env ->
- let
- tycons = getAllEnvTyCons env
- vrcs = calcTyConArgVrcs tycons
- in
-
- returnTc (tyclss, vrcs, env)
- ) `thenTc` \ (_, _, env) ->
--- traceTc (text "done" <+> ppr (map fst ty_env_stuff1)) `thenTc_`
- returnTc env
+ -- 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 $
+
+ -- 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_`
+
+ -- Step 7
+ -- Extend the environment with the final TyCons/Classes
+ -- and their implicit Ids
+ tcExtendGlobalValEnv (implicitTyThingIds all_tyclss) tcGetEnv
+
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
+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}
-tcDecl :: RecFlag -- True => recursive group
- -> ValueEnv -> InstanceMapper -> FiniteMap Name ArgVrcs
- -> RenamedTyClDecl -> TcM s (Name, TcTyThing)
-tcDecl is_rec_group unf_env inst_mapper vrcs_env decl
- = tcAddDeclCtxt decl $
--- traceTc (text "Starting" <+> ppr name) `thenTc_`
- if isClassDecl decl then
- tcClassDecl1 unf_env inst_mapper vrcs_env decl `thenTc` \ clas ->
--- traceTc (text "Finished" <+> ppr name) `thenTc_`
- returnTc (getName clas, AClass clas)
- else
- tcTyDecl is_rec_group vrcs_env decl `thenTc` \ tycon ->
--- traceTc (text "Finished" <+> ppr name) `thenTc_`
- returnTc (getName tycon, ATyCon tycon)
+%************************************************************************
+%* *
+\subsection{Step 1: Initial environment}
+%* *
+%************************************************************************
- where
- name = tyClDeclName decl
-
+\begin{code}
+getInitialKind :: RenamedTyClDecl -> NF_TcM (Name, TcKind)
+getInitialKind decl
+ = kcHsTyVars (tcdTyVars decl) `thenNF_Tc` \ arg_kinds ->
+ newKindVar `thenNF_Tc` \ result_kind ->
+ returnNF_Tc (tcdName decl, mk_kind arg_kinds result_kind)
-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)]
+mk_kind tvs_w_kinds res_kind = foldr (mkArrowKind . snd) res_kind tvs_w_kinds
\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
-
-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
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 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) = kcHsBoxedSigType 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 (tcdTyVars 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, Maybe Arity, 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,
- Just (length tyvars),
- ATyCon (pprPanic "ATyCon: syn" (ppr name))))
-
-getTyBinding1 (TyData _ _ name tyvars _ _ _ _)
- = mapNF_Tc kcHsTyVar tyvars `thenNF_Tc` \ arg_kinds ->
- returnNF_Tc (name, (foldr mkArrowKind boxedTypeKind arg_kinds,
- Nothing,
- ATyCon (error "ATyCon: data")))
-
-getTyBinding1 (ClassDecl _ name tyvars _ _ _ _ _ _ _)
- = mapNF_Tc kcHsTyVar tyvars `thenNF_Tc` \ arg_kinds ->
- returnNF_Tc (name, (foldr mkArrowKind boxedTypeKind arg_kinds,
- Just (length tyvars),
- AClass (error "AClass")))
-
--- Zonk the kind to its final form, and lookup the
--- recursive tycon/class
-getTyBinding2 rec_env (name, (tc_kind, maybe_arity, thing))
- = zonkTcKindToKind tc_kind `thenNF_Tc` \ kind ->
- returnNF_Tc (name, (kind, maybe_arity, 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 (ATyCon _) ~(Just (ATyCon tc)) = ATyCon tc
- mk_thing (AClass _) ~(Just (AClass cls)) = AClass cls
+ 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
+
+ flavour = case data_or_new of
+ NewType -> NewTyCon (mkNewTyConRep tycon)
+ DataType | all isNullaryDataCon data_cons -> EnumTyCon
+ | otherwise -> DataTyCon
+
+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
+
+ 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
+ n_fields = length sc_sel_ids + length op_items
+
+ flavour | n_fields == 1 = NewTyCon (mkNewTyConRep tycon)
+ | otherwise = 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}
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_`
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
- is_cls_decl (d, _, _) = isClassDecl d
\end{code}
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 . fst) 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])
+mkClassEdges decl@(ClassDecl {tcdCtxt = ctxt, tcdName = name}) = Just (decl, name, [c | HsPClass c _ <- ctxt])
+mkClassEdges other_decl = Nothing
-----------------------------------------------------
-get_ctxt ctxt = unionManyUniqSets (map (set_name.fst) ctxt)
-
-----------------------------------------------------
-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 (MonoTyVar name)
- = if isTvOcc (nameOccName name) then emptyUniqSet else set_name name
-get_ty (MonoTyApp ty1 ty2)
- = unionUniqSets (get_ty ty1) (get_ty ty2)
-get_ty (MonoFunTy ty1 ty2)
- = unionUniqSets (get_ty ty1) (get_ty ty2)
-get_ty (MonoListTy ty)
- = set_name listTyCon_name `unionUniqSets` get_ty ty
-get_ty (MonoTupleTy tys boxed)
- = set_name (tupleTyCon_name boxed (length tys)) `unionUniqSets` get_tys tys
-get_ty (MonoUsgTy _ ty)
- = get_ty ty
-get_ty (HsForAllTy _ ctxt mty)
- = get_ctxt ctxt `unionUniqSets` get_ty mty
-get_ty (MonoDictTy name _)
- = set_name name
-
-----------------------------------------------------
-get_tys tys
- = unionManyUniqSets (map get_ty tys)
-
-----------------------------------------------------
-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
= hsep [quotes (ppr name), ptext SLIT("at"), ppr (getSrcLoc name)]
where
name = tyClDeclName decl
-\end{code}
-
-Computing the tyConArgVrcs info
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-@tyConArgVrcs@ gives a list of (occPos,occNeg) flags, one for each
-tyvar. For @AlgTyCon@s and @SynTyCon@s, this info must be precomputed
-separately. Note that this is information about occurrences of type
-variables, not usages of term variables.
-
-The function @calcTyConArgVrcs@ must be passed a list of *algebraic or
-syntycons only* such that all tycons referred to (by mutual recursion)
-appear in the list. The fixpointing will be done on this set of
-tycons as a whole. It returns a list of @tyconVrcInfo@ data, ready to
-be (knot-tyingly?) stuck back into the appropriate fields.
-
-\begin{code}
-calcTyConArgVrcs :: [TyCon]
- -> FiniteMap Name ArgVrcs
-
-calcTyConArgVrcs tycons
- = let oi = foldl (\fm tc -> addToFM fm tc (initial tc)) emptyFM tycons
- initial tc = if isAlgTyCon tc && null (tyConDataCons tc) then
- -- make pessimistic assumption (and warn)
- take (tyConArity tc) abstractVrcs
- else
- replicate (tyConArity tc) (False,False)
- oi'' = tcaoFix oi
- go (tc,vrcs) = (getName tc,vrcs)
- in listToFM (map go (fmToList oi''))
-
- where
-
- tcaoFix :: FiniteMap TyCon ArgVrcs -- initial ArgVrcs per tycon
- -> FiniteMap TyCon ArgVrcs -- fixpointed ArgVrcs per tycon
-
- tcaoFix oi = let (changed,oi') = foldFM (\ tc pms
- (changed,oi')
- -> let pms' = tcaoIter oi' tc -- seq not simult
- in (changed || (pms /= pms'),
- addToFM oi' tc pms'))
- (False,oi) -- seq not simult for faster fixpting
- oi
- in if changed
- then tcaoFix oi'
- else oi'
-
- tcaoIter :: FiniteMap TyCon ArgVrcs -- reference ArgVrcs (initial)
- -> TyCon -- tycon to update
- -> ArgVrcs -- new ArgVrcs for tycon
-
- tcaoIter oi tc | isAlgTyCon tc
- = let cs = tyConDataCons tc
- vs = tyConTyVars tc
- argtys = concatMap dataConRawArgTys cs
- exdicttys = concatMap ((\ (_,_,_,exth,_,_) -> map (uncurry mkDictTy) exth)
- . dataConSig) cs
- myfao tc = lookupWithDefaultFM oi (expectJust "tcaoIter(Alg)" $
- tyConArgVrcs_maybe tc)
- tc
- -- we use the already-computed result for tycons not in this SCC
- in map (\v -> anyVrc (\ty -> vrcInTy myfao v ty) (exdicttys ++ argtys))
- vs
-
- tcaoIter oi tc | isSynTyCon tc
- = let (tyvs,ty) = getSynTyConDefn tc
- myfao tc = lookupWithDefaultFM oi (expectJust "tcaoIter(Syn)" $
- tyConArgVrcs_maybe tc)
- tc
- -- we use the already-computed result for tycons not in this SCC
- in map (\v -> vrcInTy myfao v ty) tyvs
-
-
-abstractVrcs :: ArgVrcs
--- we pull this out as a CAF so the warning only appears *once*
-abstractVrcs = trace ("WARNING: tyConArgVrc info inaccurate due to unavailable constructors.\n"
- ++ "\tUse -fno-prune-tydecls to fix.") $
- repeat (True,True)
\end{code}
-
-And a general variance-check function. We pass a function for
-determining the @ArgVrc@s of a tycon; when fixpointing this refers to
-the current value; otherwise this should be looked up from the tycon's
-own tyConArgVrcs.
-
-\begin{code}
-vrcInTy :: (TyCon -> ArgVrcs) -- function to get argVrcs of a tycon (break out of recursion)
- -> TyVar -- tyvar to check Vrcs of
- -> Type -- type to check for occ in
- -> (Bool,Bool) -- (occurs positively, occurs negatively)
-
-vrcInTy fao v (NoteTy (UsgNote _) ty) = vrcInTy fao v ty
-
-vrcInTy fao v (NoteTy (SynNote _) ty) = vrcInTy fao v ty
- -- SynTyCon doesn't neccessarily have vrcInfo at this point,
- -- so don't try and use it
-
-vrcInTy fao v (NoteTy (FTVNote ftv) ty) = if elemVarSet v ftv
- then vrcInTy fao v ty
- else (False,False)
- -- note that ftv cannot be calculated as occPos||occNeg,
- -- since if a tyvar occurs only as unused tyconarg,
- -- occPos==occNeg==False, but ftv=True
-
-vrcInTy fao v (TyVarTy v') = if v==v'
- then (True,False)
- else (False,False)
-
-vrcInTy fao v (AppTy ty1 ty2) = if vrcInTy fao v ty2 /= (False,False)
- then (True,True)
- else vrcInTy fao v ty1
- -- ty1 is probably unknown (or it would have been beta-reduced);
- -- hence if v occurs in ty2 at all then it could occur with
- -- either variance. Otherwise it occurs as it does in ty1.
-
-vrcInTy fao v (FunTy ty1 ty2) = let (p1,m1) = vrcInTy fao v ty1
- (p2,m2) = vrcInTy fao v ty2
- in (m1||p2,p1||m2)
-
-vrcInTy fao v (ForAllTy v' ty) = if v==v'
- then (False,False)
- else vrcInTy fao v ty
-
-vrcInTy fao v (TyConApp tc tys) = let pms1 = map (vrcInTy fao v) tys
- pms2 = fao tc
- in orVrcs (zipWith timesVrc pms1 pms2)
-
-orVrc :: (Bool,Bool) -> (Bool,Bool) -> (Bool,Bool)
-orVrc (p1,m1) (p2,m2) = (p1||p2,m1||m2)
-
-orVrcs :: [(Bool,Bool)] -> (Bool,Bool)
-orVrcs = foldl orVrc (False,False)
-
-anyVrc :: (a -> (Bool,Bool)) -> [a] -> (Bool,Bool)
-anyVrc p as = foldl (\pm a -> pm `orVrc` p a) (False,False) as
-
-timesVrc :: (Bool,Bool) -> (Bool,Bool) -> (Bool,Bool)
-timesVrc (p1,m1) (p2,m2) = (p1 && p2 || m1 && m2,
- p1 && m2 || m1 && p2)
-\end{code}
-
-
projects / ghc-hetmet.git / blobdiff