Commit 911dcb32 authored by Ian Lynagh's avatar Ian Lynagh
Browse files

Fix warnings in TcTyClsDecls

parent 2058d780
......@@ -6,13 +6,6 @@
TcTyClsDecls: Typecheck type and class declarations
\begin{code}
{-# OPTIONS -w #-}
-- The above warning supression flag is a temporary kludge.
-- While working on this module you are encouraged to remove it and fix
-- any warnings in the module. See
-- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
-- for details
module TcTyClsDecls (
tcTyAndClassDecls, tcFamInstDecl
) where
......@@ -155,7 +148,7 @@ tcTyAndClassDecls boot_details allDecls
; checkCycleErrs decls
; mod <- getModule
; traceTc (text "tcTyAndCl" <+> ppr mod)
; (syn_tycons, alg_tyclss) <- fixM (\ ~(rec_syn_tycons, rec_alg_tyclss) ->
; (syn_tycons, alg_tyclss) <- fixM (\ ~(_rec_syn_tycons, rec_alg_tyclss) ->
do { let { -- Seperate ordinary synonyms from all other type and
-- class declarations and add all associated type
-- declarations from type classes. The latter is
......@@ -359,7 +352,9 @@ tcFamInstDecl1 (decl@TyData {tcdND = new_or_data, tcdLName = L loc tc_name,
where
h98_syntax = case cons of -- All constructors have same shape
L _ (ConDecl { con_res = ResTyGADT _ }) : _ -> False
other -> True
_ -> True
tcFamInstDecl1 d = pprPanic "tcFamInstDecl1" (ppr d)
-- Kind checking of indexed types
-- -
......@@ -434,6 +429,8 @@ include the kinds of associated families into the construction of the
initial kind environment. (This is handled by `allDecls').
\begin{code}
kcTyClDecls :: [LTyClDecl Name] -> [Located (TyClDecl Name)]
-> TcM ([LTyClDecl Name], [Located (TyClDecl Name)])
kcTyClDecls syn_decls alg_decls
= do { -- First extend the kind env with each data type, class, and
-- indexed type, mapping them to a type variable
......@@ -484,7 +481,7 @@ getInitialKind decl
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
mk_res_kind _ = return liftedTypeKind
----------------
......@@ -502,7 +499,7 @@ kcSynDecls (group : groups)
kcSynDecl :: SCC (LTyClDecl Name)
-> TcM (LTyClDecl Name, -- Kind-annotated decls
(Name,TcKind)) -- Kind bindings
kcSynDecl (AcyclicSCC ldecl@(L loc decl))
kcSynDecl (AcyclicSCC (L loc decl))
= tcAddDeclCtxt decl $
kcHsTyVars (tcdTyVars decl) (\ k_tvs ->
do { traceTc (text "kcd1" <+> ppr (unLoc (tcdLName decl)) <+> brackets (ppr (tcdTyVars decl))
......@@ -517,7 +514,9 @@ kcSynDecl (CyclicSCC decls)
= do { recSynErr decls; failM } -- Fail here to avoid error cascade
-- of out-of-scope tycons
kindedTyVarKind :: LHsTyVarBndr Name -> Kind
kindedTyVarKind (L _ (KindedTyVar _ k)) = k
kindedTyVarKind x = pprPanic "kindedTyVarKind" (ppr x)
------------------------------------------------------------------------
kcTyClDecl :: TyClDecl Name -> TcM (TyClDecl Name)
......@@ -533,8 +532,7 @@ kcTyClDecl decl@(TyFamily {})
kcTyClDecl decl@(ClassDecl {tcdCtxt = ctxt, tcdSigs = sigs, tcdATs = ats})
= kcTyClDeclBody decl $ \ tvs' ->
do { is_boot <- tcIsHsBoot
; ctxt' <- kcHsContext ctxt
do { ctxt' <- kcHsContext ctxt
; ats' <- mapM (wrapLocM (kcFamilyDecl tvs')) ats
; sigs' <- mapM (wrapLocM kc_sig) sigs
; return (decl {tcdTyVars = tvs', tcdCtxt = ctxt', tcdSigs = sigs',
......@@ -547,6 +545,8 @@ kcTyClDecl decl@(ClassDecl {tcdCtxt = ctxt, tcdSigs = sigs, tcdATs = ats})
kcTyClDecl decl@(ForeignType {})
= return decl
kcTyClDecl (TySynonym {}) = panic "kcTyClDecl TySynonym"
kcTyClDeclBody :: TyClDecl Name
-> ([LHsTyVarBndr Name] -> TcM a)
-> TcM a
......@@ -558,7 +558,9 @@ kcTyClDeclBody :: TyClDecl Name
kcTyClDeclBody decl thing_inside
= tcAddDeclCtxt decl $
do { tc_ty_thing <- tcLookupLocated (tcdLName decl)
; let tc_kind = case tc_ty_thing of { AThing k -> k }
; let tc_kind = case tc_ty_thing of
AThing k -> k
_ -> pprPanic "kcTyClDeclBody" (ppr tc_ty_thing)
(kinds, _) = splitKindFunTys tc_kind
hs_tvs = tcdTyVars decl
kinded_tvs = ASSERT( length kinds >= length hs_tvs )
......@@ -607,6 +609,7 @@ kcDataDecl decl@(TyData {tcdND = new_or_data, tcdCtxt = ctxt, tcdCons = cons})
-- 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
kcDataDecl d _ = pprPanic "kcDataDecl" (ppr d)
-- Kind check a family declaration or type family default declaration.
--
......@@ -623,9 +626,11 @@ kcFamilyDecl classTvs decl@(TyFamily {tcdKind = kind})
unifyClassParmKinds (L _ (KindedTyVar n k))
| Just classParmKind <- lookup n classTyKinds = unifyKind k classParmKind
| otherwise = return ()
unifyClassParmKinds x = pprPanic "kcFamilyDecl/unifyClassParmKinds" (ppr x)
classTyKinds = [(n, k) | L _ (KindedTyVar n k) <- classTvs]
kcFamilyDecl _ decl@(TySynonym {}) -- type family defaults
kcFamilyDecl _ (TySynonym {}) -- type family defaults
= panic "TcTyClsDecls.kcFamilyDecl: not implemented yet"
kcFamilyDecl _ d = pprPanic "kcFamilyDecl" (ppr d)
\end{code}
......@@ -644,6 +649,7 @@ tcSynDecls (decl : decls)
; return (syn_tc : syn_tcs) }
-- "type"
tcSynDecl :: TyClDecl Name -> TcM TyThing
tcSynDecl
(TySynonym {tcdLName = L _ tc_name, tcdTyVars = tvs, tcdSynRhs = rhs_ty})
= tcTyVarBndrs tvs $ \ tvs' -> do
......@@ -652,6 +658,7 @@ tcSynDecl
; tycon <- buildSynTyCon tc_name tvs' (SynonymTyCon rhs_ty') Nothing
; return (ATyCon tycon)
}
tcSynDecl d = pprPanic "tcSynDecl" (ppr d)
--------------------
tcTyClDecl :: (Name -> RecFlag) -> TyClDecl Name -> TcM [TyThing]
......@@ -660,6 +667,7 @@ tcTyClDecl calc_isrec decl
= tcAddDeclCtxt decl (tcTyClDecl1 calc_isrec decl)
-- "type family" declarations
tcTyClDecl1 :: (Name -> RecFlag) -> TyClDecl Name -> TcM [TyThing]
tcTyClDecl1 _calc_isrec
(TyFamily {tcdFlavour = TypeFamily,
tcdLName = L _ tc_name, tcdTyVars = tvs, tcdKind = Just kind})
......@@ -754,7 +762,7 @@ tcTyClDecl1 calc_isrec
is_rec = calc_isrec tc_name
h98_syntax = case cons of -- All constructors have same shape
L _ (ConDecl { con_res = ResTyGADT _ }) : _ -> False
other -> True
_ -> True
tcTyClDecl1 calc_isrec
(ClassDecl {tcdLName = L _ class_name, tcdTyVars = tvs,
......@@ -801,10 +809,12 @@ tcTyClDecl1 calc_isrec
ATyCon (setTyConArgPoss tycon poss)
setTyThingPoss _ _ = panic "TcTyClsDecls.setTyThingPoss"
tcTyClDecl1 calc_isrec
tcTyClDecl1 _
(ForeignType {tcdLName = L _ tc_name, tcdExtName = tc_ext_name})
= return [ATyCon (mkForeignTyCon tc_name tc_ext_name liftedTypeKind 0)]
tcTyClDecl1 _ d = pprPanic "tcTyClDecl1" (ppr d)
-----------------------------------
tcConDecl :: Bool -- True <=> -funbox-strict_fields
-> Bool -- True <=> -XExistentialQuantificaton or -XGADTs
......@@ -878,7 +888,7 @@ tcResultType _ tc_tvs dc_tvs (ResTyGADT res_ty)
where
-- choose_univs uses the res_ty itself if it's a type variable
-- and hasn't already been used; otherwise it uses one of the tc_tvs
choose_univs used tc_tvs []
choose_univs _ tc_tvs []
= ASSERT( null tc_tvs ) []
choose_univs used (tc_tv:tc_tvs) (res_ty:res_tys)
| Just tv <- tcGetTyVar_maybe res_ty, not (tv `elem` used)
......@@ -891,6 +901,7 @@ tcResultType _ tc_tvs dc_tvs (ResTyGADT res_ty)
-- interface files and general confusion. So rename
-- the tc_tvs, since they are not used yet (no
-- consequential renaming needed)
choose_univs _ _ _ = panic "tcResultType/choose_univs"
init_occ_env = initTidyOccEnv (map getOccName dc_tvs)
(_, tidy_tc_tvs) = mapAccumL tidy_one init_occ_env tc_tvs
tidy_one env tv = (env', setTyVarName tv (tidyNameOcc name occ'))
......@@ -919,7 +930,7 @@ chooseBoxingStrategy unbox_strict_fields arg_ty bang
HsStrict | unbox_strict_fields
&& can_unbox arg_ty -> MarkedUnboxed
HsUnbox | can_unbox arg_ty -> MarkedUnboxed
other -> MarkedStrict
_ -> MarkedStrict
where
-- we can unbox if the type is a chain of newtypes with a product tycon
-- at the end
......@@ -972,6 +983,7 @@ checkValidTyCl decl
; case thing of
ATyCon tc -> checkValidTyCon tc
AClass cl -> checkValidClass cl
_ -> panic "checkValidTyCl"
; traceTc (text "Done validity of" <+> ppr thing)
}
......@@ -1023,7 +1035,7 @@ checkValidTyCon tc
-- result type against other candidates' types BOTH WAYS ROUND.
-- If they magically agrees, take the substitution and
-- apply them to the latter ones, and see if they match perfectly.
check_fields fields@((label, con1) : other_fields)
check_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
......@@ -1042,7 +1054,10 @@ checkValidTyCon tc
(tvs2, _, _, res2) = dataConSig con2
ts2 = mkVarSet tvs2
fty2 = dataConFieldType con2 label
check_fields [] = panic "checkValidTyCon/check_fields []"
checkFieldCompat :: Name -> DataCon -> DataCon -> TyVarSet
-> Type -> Type -> Type -> Type -> TcM ()
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) }
......@@ -1150,44 +1165,56 @@ checkValidClass cls
---------------------------------------------------------------------
resultTypeMisMatch :: Name -> DataCon -> DataCon -> SDoc
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 :: Name -> DataCon -> DataCon -> SDoc
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 :: Outputable a => a -> SDoc
dataConCtxt con = ptext (sLit "In the definition of data constructor") <+> quotes (ppr con)
classOpCtxt :: Var -> Type -> SDoc
classOpCtxt sel_id tau = sep [ptext (sLit "When checking the class method:"),
nest 2 (ppr sel_id <+> dcolon <+> ppr tau)]
nullaryClassErr :: Class -> SDoc
nullaryClassErr cls
= ptext (sLit "No parameters for class") <+> quotes (ppr cls)
classArityErr :: Class -> SDoc
classArityErr cls
= vcat [ptext (sLit "Too many parameters for class") <+> quotes (ppr cls),
parens (ptext (sLit "Use -XMultiParamTypeClasses to allow multi-parameter classes"))]
classFunDepsErr :: Class -> SDoc
classFunDepsErr cls
= vcat [ptext (sLit "Fundeps in class") <+> quotes (ppr cls),
parens (ptext (sLit "Use -XFunctionalDependencies to allow fundeps"))]
noClassTyVarErr :: Class -> Var -> SDoc
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 :: Class -> SDoc
genericMultiParamErr clas
= ptext (sLit "The multi-parameter class") <+> quotes (ppr clas) <+>
ptext (sLit "cannot have generic methods")
badGenericMethodType :: Name -> Kind -> SDoc
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 :: [LTyClDecl Name] -> TcRn ()
recSynErr syn_decls
= setSrcSpan (getLoc (head sorted_decls)) $
addErr (sep [ptext (sLit "Cycle in type synonym declarations:"),
......@@ -1196,6 +1223,7 @@ recSynErr syn_decls
sorted_decls = sortLocated syn_decls
ppr_decl (L loc decl) = ppr loc <> colon <+> ppr decl
recClsErr :: [Located (TyClDecl Name)] -> TcRn ()
recClsErr cls_decls
= setSrcSpan (getLoc (head sorted_decls)) $
addErr (sep [ptext (sLit "Cycle in class declarations (via superclasses):"),
......@@ -1209,73 +1237,90 @@ sortLocated things = sortLe le things
where
le (L l1 _) (L l2 _) = l1 <= l2
badDataConTyCon :: DataCon -> SDoc
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"))
badGadtDecl :: Name -> SDoc
badGadtDecl tc_name
= vcat [ ptext (sLit "Illegal generalised algebraic data declaration for") <+> quotes (ppr tc_name)
, nest 2 (parens $ ptext (sLit "Use -XGADTs to allow GADTs")) ]
badExistential :: Located Name -> SDoc
badExistential con_name
= hang (ptext (sLit "Data constructor") <+> quotes (ppr con_name) <+>
ptext (sLit "has existential type variables, or a context"))
2 (parens $ ptext (sLit "Use -XExistentialQuantification or -XGADTs to allow this"))
badStupidTheta :: Name -> SDoc
badStupidTheta tc_name
= ptext (sLit "A data type declared in GADT style cannot have a context:") <+> quotes (ppr tc_name)
newtypeConError :: Name -> Int -> SDoc
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 :: DataCon -> SDoc
newtypeExError con
= sep [ptext (sLit "A newtype constructor cannot have an existential context,"),
nest 2 $ ptext (sLit "but") <+> quotes (ppr con) <+> ptext (sLit "does")]
newtypeStrictError :: DataCon -> SDoc
newtypeStrictError con
= sep [ptext (sLit "A newtype constructor cannot have a strictness annotation,"),
nest 2 $ ptext (sLit "but") <+> quotes (ppr con) <+> ptext (sLit "does")]
newtypePredError :: DataCon -> SDoc
newtypePredError con
= sep [ptext (sLit "A newtype constructor must have a return type of form T a1 ... an"),
nest 2 $ ptext (sLit "but") <+> quotes (ppr con) <+> ptext (sLit "does not")]
newtypeFieldErr :: DataCon -> Int -> SDoc
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]
badSigTyDecl :: Name -> SDoc
badSigTyDecl tc_name
= vcat [ ptext (sLit "Illegal kind signature") <+>
quotes (ppr tc_name)
, nest 2 (parens $ ptext (sLit "Use -XKindSignatures to allow kind signatures")) ]
badFamInstDecl :: Outputable a => a -> SDoc
badFamInstDecl tc_name
= vcat [ ptext (sLit "Illegal family instance for") <+>
quotes (ppr tc_name)
, nest 2 (parens $ ptext (sLit "Use -XTypeFamilies to allow indexed type families")) ]
badGadtIdxTyDecl :: Name -> SDoc
badGadtIdxTyDecl tc_name
= vcat [ ptext (sLit "Illegal generalised algebraic data declaration for") <+>
quotes (ppr tc_name)
, nest 2 (parens $ ptext (sLit "Family instances can not yet use GADT declarations")) ]
tooManyParmsErr :: Located Name -> SDoc
tooManyParmsErr tc_name
= ptext (sLit "Family instance has too many parameters:") <+>
quotes (ppr tc_name)
tooFewParmsErr :: Arity -> SDoc
tooFewParmsErr arity
= ptext (sLit "Family instance has too few parameters; expected") <+>
ppr arity
wrongNumberOfParmsErr :: Arity -> SDoc
wrongNumberOfParmsErr exp_arity
= ptext (sLit "Number of parameters must match family declaration; expected")
<+> ppr exp_arity
badBootFamInstDeclErr :: SDoc
badBootFamInstDeclErr =
ptext (sLit "Illegal family instance in hs-boot file")
wrongKindOfFamily :: TyCon -> SDoc
wrongKindOfFamily family =
ptext (sLit "Wrong category of family instance; declaration was for a") <+>
kindOfFamily
......@@ -1284,6 +1329,7 @@ wrongKindOfFamily family =
| isAlgTyCon family = ptext (sLit "data type")
| otherwise = pprPanic "wrongKindOfFamily" (ppr family)
emptyConDeclsErr :: Name -> SDoc
emptyConDeclsErr tycon
= sep [quotes (ppr tycon) <+> ptext (sLit "has no constructors"),
nest 2 $ ptext (sLit "(-XEmptyDataDecls permits this)")]
......
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