%
-% (c) The GRASP/AQUA Project, Glasgow University, 1993-1996
+% (c) The GRASP/AQUA Project, Glasgow University, 1993-1998
%
\section[StgLint]{A ``lint'' pass to check for Stg correctness}
import StgSyn
import Bag ( Bag, emptyBag, isEmptyBag, snocBag, foldBag )
-import Id ( idType, isAlgCon, dataConArgTys,
- emptyIdSet, isEmptyIdSet, elementOfIdSet,
- mkIdSet, intersectIdSets,
- unionIdSets, idSetToList, IdSet,
- GenId{-instanced NamedThing-}, Id
- )
-import Literal ( literalType, Literal{-instance Outputable-} )
+import Id ( Id, idType )
+import VarSet
+import DataCon ( DataCon, dataConArgTys, dataConType )
+import Const ( literalType, conType, Literal )
import Maybes ( catMaybes )
import Name ( isLocallyDefined, getSrcLoc )
-import ErrUtils ( ErrMsg )
-import PrimOp ( primOpType )
-import SrcLoc ( SrcLoc{-instance Outputable-} )
-import Type ( mkFunTys, splitFunTys, splitAlgTyConApp_maybe,
- isTyVarTy, Type
+import ErrUtils ( ErrMsg, Message, addErrLocHdrLine, pprBagOfErrors, dontAddErrLoc )
+import Type ( mkFunTys, splitFunTys, splitAlgTyConApp_maybe,
+ isUnLiftedType, isTyVarTy, splitForAllTys, Type
)
import TyCon ( TyCon, isDataTyCon )
import Util ( zipEqual )
-import GlaExts ( trace )
import Outputable
infixr 9 `thenL`, `thenL_`, `thenMaybeL`, `thenMaybeL_`
-
-unDictifyTy = panic "StgLint.unDictifyTy (ToDo)"
\end{code}
Checks for
case (initL (lint_binds binds)) of
Nothing -> binds
Just msg -> pprPanic "" (vcat [
- ptext SLIT("*** Stg Lint ErrMsgs: in "),text whodunnit, ptext SLIT(" ***"),
+ ptext SLIT("*** Stg Lint ErrMsgs: in") <+> text whodunnit <+> ptext SLIT("***"),
msg,
ptext SLIT("*** Offending Program ***"),
pprStgBindings binds,
\begin{code}
lintStgArg :: StgArg -> LintM (Maybe Type)
+lintStgArg (StgConArg con) = returnL (Just (conType con))
+lintStgArg (StgVarArg v) = lintStgVar v
-lintStgArg (StgLitArg lit) = returnL (Just (literalType lit))
-lintStgArg (StgConArg con) = returnL (Just (idType con))
-lintStgArg a@(StgVarArg v)
- = checkInScope v `thenL_`
- returnL (Just (idType v))
+lintStgVar v = checkInScope v `thenL_`
+ returnL (Just (idType v))
\end{code}
\begin{code}
-- Check the rhs
lintStgRhs rhs `thenL` \ maybe_rhs_ty ->
+ -- Check binder doesn't have unlifted type
+ checkL (not (isUnLiftedType binder_ty))
+ (mkUnLiftedTyMsg binder rhs) `thenL_`
+
-- Check match to RHS type
(case maybe_rhs_ty of
Nothing -> returnL ()
- Just rhs_ty -> checkTys (idType binder)
+ Just rhs_ty -> checkTys binder_ty
rhs_ty
(mkRhsMsg binder rhs_ty)
) `thenL_`
returnL ()
)
+ where
+ binder_ty = idType binder
\end{code}
\begin{code}
lintStgRhs :: StgRhs -> LintM (Maybe Type)
-lintStgRhs (StgRhsClosure _ _ _ _ binders expr)
+lintStgRhs (StgRhsClosure _ _ _ _ _ [] expr)
+ = lintStgExpr expr
+
+lintStgRhs (StgRhsClosure _ _ _ _ _ binders expr)
= addLoc (LambdaBodyOf binders) (
addInScopeVars binders (
lintStgExpr expr `thenMaybeL` \ body_ty ->
Nothing -> returnL Nothing
Just arg_tys -> checkFunApp con_ty arg_tys (mkRhsConMsg con_ty arg_tys)
where
- con_ty = idType con
+ con_ty = dataConType con
\end{code}
\begin{code}
lintStgExpr :: StgExpr -> LintM (Maybe Type) -- Nothing if error found
-lintStgExpr e@(StgApp fun args _)
- = lintStgArg fun `thenMaybeL` \ fun_ty ->
+lintStgExpr e@(StgApp fun args)
+ = lintStgVar fun `thenMaybeL` \ fun_ty ->
mapMaybeL lintStgArg args `thenL` \ maybe_arg_tys ->
case maybe_arg_tys of
Nothing -> returnL Nothing
Nothing -> returnL Nothing
Just arg_tys -> checkFunApp con_ty arg_tys (mkFunAppMsg con_ty arg_tys e)
where
- con_ty = idType con
+ con_ty = conType con
-lintStgExpr e@(StgPrim op args _)
- = mapMaybeL lintStgArg args `thenL` \ maybe_arg_tys ->
- case maybe_arg_tys of
- Nothing -> returnL Nothing
- Just arg_tys -> checkFunApp op_ty arg_tys (mkFunAppMsg op_ty arg_tys e)
- where
- op_ty = primOpType op
+lintStgExpr (StgLam _ bndrs _)
+ = addErrL (ptext SLIT("Unexpected StgLam") <+> ppr bndrs) `thenL_`
+ returnL Nothing
lintStgExpr (StgLet binds body)
= lintStgBinds binds `thenL` \ binders ->
lintStgExpr body
))
-lintStgExpr (StgSCC _ _ expr) = lintStgExpr expr
+lintStgExpr (StgSCC _ expr) = lintStgExpr expr
-lintStgExpr e@(StgCase scrut _ _ _ alts)
+lintStgExpr e@(StgCase scrut _ _ bndr _ alts)
= lintStgExpr scrut `thenMaybeL` \ _ ->
+ checkTys (idType bndr) scrut_ty (mkDefltMsg bndr) `thenL_`
+
+ (trace (showSDoc (ppr e)) $
+ -- we only allow case of tail-call or primop.
+ (case scrut of
+ StgApp _ _ -> returnL ()
+ StgCon _ _ _ -> returnL ()
+ other -> addErrL (mkCaseOfCaseMsg e)) `thenL_`
- -- Check that it is a data type
- case (splitAlgTyConApp_maybe scrut_ty) of
- Just (tycon, _, _) | isDataTyCon tycon
- -> lintStgAlts alts scrut_ty tycon
- other -> addErrL (mkCaseDataConMsg e) `thenL_`
- returnL Nothing
+ addInScopeVars [bndr] (lintStgAlts alts scrut_ty)
+ )
where
scrut_ty = get_ty alts
\begin{code}
lintStgAlts :: StgCaseAlts
-> Type -- Type of scrutinee
- -> TyCon -- TyCon pinned on the case
-> LintM (Maybe Type) -- Type of alternatives
-lintStgAlts alts scrut_ty case_tycon
+lintStgAlts alts scrut_ty
= (case alts of
StgAlgAlts _ alg_alts deflt ->
mapL (lintAlgAlt scrut_ty) alg_alts `thenL` \ maybe_alt_tys ->
Just (tycon, tys_applied, cons) ->
let
arg_tys = dataConArgTys con tys_applied
+ -- This almost certainly does not work for existential constructors
in
checkL (con `elem` cons) (mkAlgAltMsg2 scrut_ty con) `thenL_`
checkL (length arg_tys == length args) (mkAlgAltMsg3 con args)
lintStgExpr rhs
lintDeflt StgNoDefault scrut_ty = returnL Nothing
-lintDeflt deflt@(StgBindDefault binder _ rhs) scrut_ty
- = checkTys (idType binder) scrut_ty (mkDefltMsg deflt) `thenL_`
- addInScopeVars [binder] (
- lintStgExpr rhs
- )
+lintDeflt deflt@(StgBindDefault rhs) scrut_ty = lintStgExpr rhs
\end{code}
| LambdaBodyOf [Id] -- The lambda-binder
| BodyOfLetRec [Id] -- One of the binders
-instance Outputable LintLocInfo where
- ppr (RhsOf v)
- = hcat [ppr (getSrcLoc v), ptext SLIT(": [RHS of "), pp_binders [v], char ']']
+dumpLoc (RhsOf v) =
+ (getSrcLoc v, ptext SLIT(" [RHS of ") <> pp_binders [v] <> char ']' )
+dumpLoc (LambdaBodyOf bs) =
+ (getSrcLoc (head bs), ptext SLIT(" [in body of lambda with binders ") <> pp_binders bs <> char ']' )
- ppr (LambdaBodyOf bs)
- = hcat [ppr (getSrcLoc (head bs)),
- ptext SLIT(": [in body of lambda with binders "), pp_binders bs, char ']']
+dumpLoc (BodyOfLetRec bs) =
+ (getSrcLoc (head bs), ptext SLIT(" [in body of letrec with binders ") <> pp_binders bs <> char ']' )
- ppr (BodyOfLetRec bs)
- = hcat [ppr (getSrcLoc (head bs)),
- ptext SLIT(": [in body of letrec with binders "), pp_binders bs, char ']']
pp_binders :: [Id] -> SDoc
pp_binders bs
= sep (punctuate comma (map pp_binder bs))
where
pp_binder b
- = hsep [ppr b, ptext SLIT("::"), ppr (idType b)]
+ = hsep [ppr b, dcolon, ppr (idType b)]
\end{code}
\begin{code}
-initL :: LintM a -> Maybe ErrMsg
+initL :: LintM a -> Maybe Message
initL m
- = case (m [] emptyIdSet emptyBag) of { (_, errs) ->
+ = case (m [] emptyVarSet emptyBag) of { (_, errs) ->
if isEmptyBag errs then
Nothing
else
- Just (foldBag ($$) (\ msg -> msg) empty errs)
+ Just (pprBagOfErrors errs)
}
returnL :: a -> LintM a
\end{code}
\begin{code}
-checkL :: Bool -> ErrMsg -> LintM ()
+checkL :: Bool -> Message -> LintM ()
checkL True msg loc scope errs = ((), errs)
checkL False msg loc scope errs = ((), addErr errs msg loc)
-addErrL :: ErrMsg -> LintM ()
+addErrL :: Message -> LintM ()
addErrL msg loc scope errs = ((), addErr errs msg loc)
-addErr :: Bag ErrMsg -> ErrMsg -> [LintLocInfo] -> Bag ErrMsg
+addErr :: Bag ErrMsg -> Message -> [LintLocInfo] -> Bag ErrMsg
addErr errs_so_far msg locs
- = errs_so_far `snocBag` (hang (ppr (head locs)) 4 msg)
+ = errs_so_far `snocBag` mk_msg locs
+ where
+ mk_msg (loc:_) = let (l,hdr) = dumpLoc loc in addErrLocHdrLine l hdr msg
+ mk_msg [] = dontAddErrLoc "" msg
addLoc :: LintLocInfo -> LintM a -> LintM a
addLoc extra_loc m loc scope errs
-- For now, it's just a "trace"; we may make
-- a real error out of it...
let
- new_set = mkIdSet ids
+ new_set = mkVarSet ids
- shadowed = scope `intersectIdSets` new_set
+ shadowed = scope `intersectVarSet` new_set
in
-- After adding -fliberate-case, Simon decided he likes shadowed
-- names after all. WDP 94/07
--- (if isEmptyIdSet shadowed
+-- (if isEmptyVarSet shadowed
-- then id
--- else pprTrace "Shadowed vars:" (ppr (idSetToList shadowed))) $
- m loc (scope `unionIdSets` new_set) errs
+-- else pprTrace "Shadowed vars:" (ppr (varSetElems shadowed))) $
+ m loc (scope `unionVarSet` new_set) errs
\end{code}
+Checking function applications: we only check that the type has the
+right *number* of arrows, we don't actually compare the types. This
+is because we can't expect the types to be equal - the type
+applications and type lambdas that we use to calculate accurate types
+have long since disappeared.
+
\begin{code}
-checkFunApp :: Type -- The function type
- -> [Type] -- The arg type(s)
- -> ErrMsg -- Error messgae
- -> LintM (Maybe Type) -- The result type
+checkFunApp :: Type -- The function type
+ -> [Type] -- The arg type(s)
+ -> Message -- Error messgae
+ -> LintM (Maybe Type) -- The result type
checkFunApp fun_ty arg_tys msg loc scope errs
= cfa res_ty expected_arg_tys arg_tys
where
- (expected_arg_tys, res_ty) = splitFunTys fun_ty
+ (_, de_forall_ty) = splitForAllTys fun_ty
+ (expected_arg_tys, res_ty) = splitFunTys de_forall_ty
cfa res_ty expected [] -- Args have run out; that's fine
= (Just (mkFunTys expected res_ty), errs)
| isTyVarTy res_ty
= (Just res_ty, errs)
| otherwise
- = case splitFunTys (unDictifyTy res_ty) of
+ = case splitFunTys res_ty of
([], _) -> (Nothing, addErr errs msg loc) -- Too many args
(new_expected, new_res) -> cfa new_res new_expected arg_tys
cfa res_ty (expected_arg_ty:expected_arg_tys) (arg_ty:arg_tys)
- = if (sleazy_eq_ty expected_arg_ty arg_ty)
- then cfa res_ty expected_arg_tys arg_tys
- else (Nothing, addErr errs msg loc) -- Arg mis-match
+ = cfa res_ty expected_arg_tys arg_tys
\end{code}
\begin{code}
checkInScope :: Id -> LintM ()
checkInScope id loc scope errs
- = if isLocallyDefined id && not (isAlgCon id) && not (id `elementOfIdSet` scope) then
+ = if isLocallyDefined id && not (id `elemVarSet` scope) then
((), addErr errs (hsep [ppr id, ptext SLIT("is out of scope")]) loc)
else
((), errs)
-checkTys :: Type -> Type -> ErrMsg -> LintM ()
+checkTys :: Type -> Type -> Message -> LintM ()
checkTys ty1 ty2 msg loc scope errs
- = if (sleazy_eq_ty ty1 ty2)
- then ((), errs)
- else ((), addErr errs msg loc)
+ = -- if (ty1 == ty2) then
+ ((), errs)
+ -- else ((), addErr errs msg loc)
\end{code}
\begin{code}
-mkCaseAltMsg :: StgCaseAlts -> ErrMsg
+mkCaseAltMsg :: StgCaseAlts -> Message
mkCaseAltMsg alts
= ($$) (text "In some case alternatives, type of alternatives not all same:")
- -- LATER: (ppr alts)
- (panic "mkCaseAltMsg")
-
-mkCaseDataConMsg :: StgExpr -> ErrMsg
-mkCaseDataConMsg expr
- = ($$) (ptext SLIT("A case scrutinee not a type-constructor type:"))
- (pp_expr expr)
+ (empty) -- LATER: ppr alts
-mkCaseAbstractMsg :: TyCon -> ErrMsg
+mkCaseAbstractMsg :: TyCon -> Message
mkCaseAbstractMsg tycon
= ($$) (ptext SLIT("An algebraic case on an abstract type:"))
(ppr tycon)
-mkDefltMsg :: StgCaseDefault -> ErrMsg
-mkDefltMsg deflt
- = ($$) (ptext SLIT("Binder in default case of a case expression doesn't match type of scrutinee:"))
- --LATER: (ppr deflt)
+mkDefltMsg :: Id -> Message
+mkDefltMsg bndr
+ = ($$) (ptext SLIT("Binder of a case expression doesn't match type of scrutinee:"))
(panic "mkDefltMsg")
-mkFunAppMsg :: Type -> [Type] -> StgExpr -> ErrMsg
+mkFunAppMsg :: Type -> [Type] -> StgExpr -> Message
mkFunAppMsg fun_ty arg_tys expr
= vcat [text "In a function application, function type doesn't match arg types:",
hang (ptext SLIT("Function type:")) 4 (ppr fun_ty),
hang (ptext SLIT("Arg types:")) 4 (vcat (map (ppr) arg_tys)),
- hang (ptext SLIT("Expression:")) 4 (pp_expr expr)]
+ hang (ptext SLIT("Expression:")) 4 (ppr expr)]
-mkRhsConMsg :: Type -> [Type] -> ErrMsg
+mkRhsConMsg :: Type -> [Type] -> Message
mkRhsConMsg fun_ty arg_tys
= vcat [text "In a RHS constructor application, con type doesn't match arg types:",
hang (ptext SLIT("Constructor type:")) 4 (ppr fun_ty),
hang (ptext SLIT("Arg types:")) 4 (vcat (map (ppr) arg_tys))]
-mkUnappTyMsg :: Id -> Type -> ErrMsg
+mkUnappTyMsg :: Id -> Type -> Message
mkUnappTyMsg var ty
= vcat [text "Variable has a for-all type, but isn't applied to any types.",
(<>) (ptext SLIT("Var: ")) (ppr var),
(<>) (ptext SLIT("Its type: ")) (ppr ty)]
-mkAlgAltMsg1 :: Type -> ErrMsg
+mkAlgAltMsg1 :: Type -> Message
mkAlgAltMsg1 ty
= ($$) (text "In some case statement, type of scrutinee is not a data type:")
(ppr ty)
-mkAlgAltMsg2 :: Type -> Id -> ErrMsg
+mkAlgAltMsg2 :: Type -> DataCon -> Message
mkAlgAltMsg2 ty con
= vcat [
text "In some algebraic case alternative, constructor is not a constructor of scrutinee type:",
ppr con
]
-mkAlgAltMsg3 :: Id -> [Id] -> ErrMsg
+mkAlgAltMsg3 :: DataCon -> [Id] -> Message
mkAlgAltMsg3 con alts
= vcat [
text "In some algebraic case alternative, number of arguments doesn't match constructor:",
ppr alts
]
-mkAlgAltMsg4 :: Type -> Id -> ErrMsg
+mkAlgAltMsg4 :: Type -> Id -> Message
mkAlgAltMsg4 ty arg
= vcat [
text "In some algebraic case alternative, type of argument doesn't match data constructor:",
ppr arg
]
-mkPrimAltMsg :: (Literal, StgExpr) -> ErrMsg
+mkPrimAltMsg :: (Literal, StgExpr) -> Message
mkPrimAltMsg alt
- = ($$) (text "In a primitive case alternative, type of literal doesn't match type of scrutinee:")
- (ppr alt)
+ = text "In a primitive case alternative, type of literal doesn't match type of scrutinee:"
+ $$ ppr alt
-mkRhsMsg :: Id -> Type -> ErrMsg
+mkCaseOfCaseMsg :: StgExpr -> Message
+mkCaseOfCaseMsg e
+ = text "Case of non-tail-call:" $$ ppr e
+
+mkRhsMsg :: Id -> Type -> Message
mkRhsMsg binder ty
= vcat [hsep [ptext SLIT("The type of this binder doesn't match the type of its RHS:"),
ppr binder],
hsep [ptext SLIT("Rhs type:"), ppr ty]
]
-pp_expr :: StgExpr -> SDoc
-pp_expr expr = ppr expr
-
-sleazy_eq_ty ty1 ty2
- -- NB: probably severe overkill (WDP 95/04)
- = trace "StgLint.sleazy_eq_ty:use eqSimplTy?" $
- case (splitFunTys ty1) of { (tyargs1,tyres1) ->
- case (splitFunTys ty2) of { (tyargs2,tyres2) ->
- let
- ty11 = mkFunTys tyargs1 tyres1
- ty22 = mkFunTys tyargs2 tyres2
- in
- ty11 == ty22 }}
+mkUnLiftedTyMsg binder rhs
+ = (ptext SLIT("Let(rec) binder") <+> quotes (ppr binder) <+>
+ ptext SLIT("has unlifted type") <+> quotes (ppr (idType binder)))
+ $$
+ (ptext SLIT("RHS:") <+> ppr rhs)
\end{code}