import StgSyn
-import Bag ( Bag, emptyBag, isEmptyBag, snocBag, foldBag )
-import Id ( Id, idType )
+import Bag ( Bag, emptyBag, isEmptyBag, snocBag, bagToList )
+import Id ( Id, idType, isLocalId )
import VarSet
-import DataCon ( DataCon, dataConArgTys, dataConType )
-import Const ( literalType, conType, Literal )
+import DataCon ( DataCon, dataConArgTys, dataConRepType )
+import PrimOp ( primOpType )
+import Literal ( literalType, Literal )
import Maybes ( catMaybes )
-import Name ( isLocallyDefined, getSrcLoc )
-import ErrUtils ( ErrMsg )
-import Type ( mkFunTys, splitFunTys, splitAlgTyConApp_maybe,
- isUnLiftedType, isTyVarTy, Type
+import Name ( getSrcLoc )
+import ErrUtils ( Message, addErrLocHdrLine )
+import Type ( mkFunTys, splitFunTys, splitTyConApp_maybe,
+ isUnLiftedType, isTyVarTy, dropForAlls, Type
)
-import TyCon ( TyCon, isDataTyCon )
-import Util ( zipEqual, trace )
+import TyCon ( TyCon, isAlgTyCon, isNewTyCon, tyConDataCons )
+import Util ( zipEqual, equalLength )
import Outputable
infixr 9 `thenL`, `thenL_`, `thenMaybeL`, `thenMaybeL_`
(a) *some* type errors
(b) locally-defined variables used but not defined
+
+Note: unless -dverbose-stg is on, display of lint errors will result
+in "panic: bOGUS_LVs".
+
+WARNING:
+~~~~~~~~
+
+This module has suffered bit-rot; it is likely to yield lint errors
+for Stg code that is currently perfectly acceptable for code
+generation. Solution: don't use it! (KSW 2000-05).
+
+
%************************************************************************
%* *
\subsection{``lint'' for various constructs}
\begin{code}
lintStgArg :: StgArg -> LintM (Maybe Type)
-lintStgArg (StgConArg con) = returnL (Just (conType con))
+lintStgArg (StgLitArg lit) = returnL (Just (literalType lit))
lintStgArg (StgVarArg v) = lintStgVar v
lintStgVar v = checkInScope v `thenL_`
\begin{code}
lintStgRhs :: StgRhs -> LintM (Maybe Type)
+lintStgRhs (StgRhsClosure _ _ _ _ _ [] expr)
+ = lintStgExpr expr
+
lintStgRhs (StgRhsClosure _ _ _ _ _ binders expr)
= addLoc (LambdaBodyOf binders) (
addInScopeVars binders (
Nothing -> returnL Nothing
Just arg_tys -> checkFunApp con_ty arg_tys (mkRhsConMsg con_ty arg_tys)
where
- con_ty = dataConType con
+ con_ty = dataConRepType con
\end{code}
\begin{code}
lintStgExpr :: StgExpr -> LintM (Maybe Type) -- Nothing if error found
+lintStgExpr (StgLit l) = returnL (Just (literalType l))
+
lintStgExpr e@(StgApp fun args)
= lintStgVar fun `thenMaybeL` \ fun_ty ->
mapMaybeL lintStgArg args `thenL` \ maybe_arg_tys ->
Nothing -> returnL Nothing
Just arg_tys -> checkFunApp fun_ty arg_tys (mkFunAppMsg fun_ty arg_tys e)
-lintStgExpr e@(StgCon con args _)
+lintStgExpr e@(StgConApp con args)
= mapMaybeL lintStgArg args `thenL` \ maybe_arg_tys ->
case maybe_arg_tys of
Nothing -> returnL Nothing
Just arg_tys -> checkFunApp con_ty arg_tys (mkFunAppMsg con_ty arg_tys e)
where
- con_ty = conType con
+ con_ty = dataConRepType con
+
+lintStgExpr e@(StgOpApp (StgFCallOp _ _) args res_ty)
+ = -- We don't have enough type information to check
+ -- the application; ToDo
+ mapMaybeL lintStgArg args `thenL` \ maybe_arg_tys ->
+ returnL (Just res_ty)
+
+lintStgExpr e@(StgOpApp (StgPrimOp 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 e@(StgCase scrut _ _ bndr _ alts)
= lintStgExpr scrut `thenMaybeL` \ _ ->
- checkTys (idType bndr) scrut_ty (mkDefltMsg bndr) `thenL_`
-
- -- Check that it is a data type
- case (splitAlgTyConApp_maybe scrut_ty) of
- Just (tycon, _, _) | isDataTyCon tycon
- -> addInScopeVars [bndr] (lintStgAlts alts scrut_ty tycon)
- other -> addErrL (mkCaseDataConMsg e) `thenL_`
- returnL Nothing
- where
- scrut_ty = get_ty alts
- get_ty (StgAlgAlts ty _ _) = ty
- get_ty (StgPrimAlts ty _ _) = ty
+ (case alts of
+ StgPrimAlts tc _ _ -> check_bndr tc
+ StgAlgAlts (Just tc) _ _ -> check_bndr tc
+ StgAlgAlts Nothing _ _ -> returnL ()
+ ) `thenL_`
+
+ (trace (showSDoc (ppr e)) $
+ -- we only allow case of tail-call or primop.
+ (case scrut of
+ StgApp _ _ -> returnL ()
+ StgConApp _ _ -> returnL ()
+ other -> addErrL (mkCaseOfCaseMsg e)) `thenL_`
+
+ addInScopeVars [bndr] (lintStgAlts alts scrut_ty)
+ )
+ where
+ scrut_ty = idType bndr
+ bad_bndr = mkDefltMsg bndr
+ check_bndr tc = case splitTyConApp_maybe scrut_ty of
+ Just (bndr_tc, _) -> checkL (tc == bndr_tc) bad_bndr
+ Nothing -> addErrL bad_bndr
\end{code}
\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 ->
check ty = checkTys first_ty ty (mkCaseAltMsg alts)
lintAlgAlt scrut_ty (con, args, _, rhs)
- = (case splitAlgTyConApp_maybe scrut_ty of
- Nothing ->
- addErrL (mkAlgAltMsg1 scrut_ty)
- Just (tycon, tys_applied, cons) ->
+ = (case splitTyConApp_maybe scrut_ty of
+ Just (tycon, tys_applied) | isAlgTyCon tycon &&
+ not (isNewTyCon tycon) ->
let
+ cons = tyConDataCons tycon
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)
+ checkL (equalLength arg_tys args) (mkAlgAltMsg3 con args)
`thenL_`
mapL check (zipEqual "lintAlgAlt:stg" arg_tys args) `thenL_`
returnL ()
+ other ->
+ addErrL (mkAlgAltMsg1 scrut_ty)
) `thenL_`
addInScopeVars args (
lintStgExpr rhs
\begin{code}
type LintM a = [LintLocInfo] -- Locations
-> IdSet -- Local vars in scope
- -> Bag ErrMsg -- Error messages so far
- -> (a, Bag ErrMsg) -- Result and error messages (if any)
+ -> Bag Message -- Error messages so far
+ -> (a, Bag Message) -- Result and error messages (if any)
data LintLocInfo
= RhsOf Id -- The variable bound
| 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 [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 [] emptyVarSet emptyBag) of { (_, errs) ->
if isEmptyBag errs then
Nothing
else
- Just (foldBag ($$) (\ msg -> msg) empty errs)
+ Just (vcat (punctuate (text "") (bagToList 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 Message -> Message -> [LintLocInfo] -> Bag Message
addErr errs_so_far msg locs
= errs_so_far `snocBag` mk_msg locs
where
- mk_msg (loc:_) = hang (ppr loc) 4 msg
+ mk_msg (loc:_) = let (l,hdr) = dumpLoc loc
+ in addErrLocHdrLine l hdr msg
mk_msg [] = msg
addLoc :: LintLocInfo -> LintM a -> LintM a
-- a real error out of it...
let
new_set = mkVarSet ids
-
- shadowed = scope `intersectVarSet` new_set
in
-- After adding -fliberate-case, Simon decided he likes shadowed
-- names after all. WDP 94/07
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
+ (expected_arg_tys, res_ty) = splitFunTys (dropForAlls fun_ty)
cfa res_ty expected [] -- Args have run out; that's fine
= (Just (mkFunTys expected res_ty), errs)
(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 (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 (id `elemVarSet` scope) then
+ = if isLocalId 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 (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")
+ (empty) -- LATER: ppr alts
-mkCaseDataConMsg :: StgExpr -> ErrMsg
-mkCaseDataConMsg expr
- = ($$) (ptext SLIT("A case scrutinee not a type-constructor type:"))
- (ppr expr)
-
-mkCaseAbstractMsg :: TyCon -> ErrMsg
+mkCaseAbstractMsg :: TyCon -> Message
mkCaseAbstractMsg tycon
= ($$) (ptext SLIT("An algebraic case on an abstract type:"))
(ppr tycon)
-mkDefltMsg :: Id -> ErrMsg
+mkDefltMsg :: Id -> Message
mkDefltMsg bndr
= ($$) (ptext SLIT("Binder of a case expression doesn't match type of scrutinee:"))
(panic "mkDefltMsg")
-mkFunAppMsg :: Type -> [Type] -> StgExpr -> ErrMsg
+mkFunAppMsg :: Type -> [Type] -> StgExpr -> Message
mkFunAppMsg fun_ty arg_tys expr
= vcat [text "In a function application, function type doesn't match arg types:",
hang (ptext SLIT("Function type:")) 4 (ppr fun_ty),
hang (ptext SLIT("Arg types:")) 4 (vcat (map (ppr) arg_tys)),
hang (ptext SLIT("Expression:")) 4 (ppr expr)]
-mkRhsConMsg :: Type -> [Type] -> ErrMsg
+mkRhsConMsg :: Type -> [Type] -> Message
mkRhsConMsg fun_ty arg_tys
= vcat [text "In a RHS constructor application, con type doesn't match arg types:",
hang (ptext SLIT("Constructor type:")) 4 (ppr fun_ty),
hang (ptext SLIT("Arg types:")) 4 (vcat (map (ppr) arg_tys))]
-mkUnappTyMsg :: Id -> Type -> ErrMsg
+mkUnappTyMsg :: Id -> Type -> Message
mkUnappTyMsg var ty
= vcat [text "Variable has a for-all type, but isn't applied to any types.",
(<>) (ptext SLIT("Var: ")) (ppr var),
(<>) (ptext SLIT("Its type: ")) (ppr ty)]
-mkAlgAltMsg1 :: Type -> ErrMsg
+mkAlgAltMsg1 :: Type -> Message
mkAlgAltMsg1 ty
= ($$) (text "In some case statement, type of scrutinee is not a data type:")
(ppr ty)
-mkAlgAltMsg2 :: Type -> DataCon -> 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 :: DataCon -> [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:"
$$ ppr alt
-mkRhsMsg :: Id -> Type -> ErrMsg
+mkCaseOfCaseMsg :: StgExpr -> Message
+mkCaseOfCaseMsg e
+ = text "Case of non-tail-call:" $$ 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],