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, dataConInstArgTys, dataConRepType )
+import CoreSyn ( AltCon(..) )
+import PrimOp ( primOpType )
+import Literal ( literalType )
import Maybes ( catMaybes )
-import Name ( isLocallyDefined, getSrcLoc )
-import ErrUtils ( ErrMsg, Message, addErrLocHdrLine, pprBagOfErrors, dontAddErrLoc )
-import Type ( mkFunTys, splitFunTys, splitAlgTyConApp_maybe,
- isUnLiftedType, isTyVarTy, Type
+import Name ( getSrcLoc )
+import ErrUtils ( Message, mkLocMessage )
+import Type ( mkFunTys, splitFunTys, splitTyConApp_maybe,
+ isUnLiftedType, isTyVarTy, dropForAlls, Type
)
-import TyCon ( TyCon, isDataTyCon )
-import Util ( zipEqual )
+import TyCon ( isAlgTyCon, isNewTyCon, tyConDataCons )
+import Util ( zipEqual, equalLength )
+import SrcLoc ( srcLocSpan )
import Outputable
-infixr 9 `thenL`, `thenL_`, `thenMaybeL`, `thenMaybeL_`
+infixr 9 `thenL`, `thenL_`, `thenMaybeL`
\end{code}
Checks for
(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}
lintStgBindings :: String -> [StgBinding] -> [StgBinding]
lintStgBindings whodunnit binds
- = _scc_ "StgLint"
+ = {-# SCC "StgLint" #-}
case (initL (lint_binds binds)) of
Nothing -> binds
Just msg -> pprPanic "" (vcat [
\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_`
lintStgExpr (StgSCC _ expr) = lintStgExpr expr
-lintStgExpr e@(StgCase scrut _ _ bndr _ alts)
+lintStgExpr e@(StgCase scrut _ _ bndr _ alts_type 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
+
+ (case alts_type of
+ AlgAlt tc -> check_bndr tc
+ PrimAlt tc -> check_bndr tc
+ UbxTupAlt tc -> check_bndr tc
+ PolyAlt -> returnL ()
+ ) `thenL_`
+
+ (trace (showSDoc (ppr e)) $
+ -- we only allow case of tail-call or primop.
+ (case scrut of
+ StgApp _ _ -> returnL ()
+ StgConApp _ _ -> returnL ()
+ StgOpApp _ _ _ -> returnL ()
+ other -> addErrL (mkCaseOfCaseMsg e)) `thenL_`
+
+ addInScopeVars [bndr] (lintStgAlts alts scrut_ty)
+ )
where
- scrut_ty = get_ty alts
+ 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
- get_ty (StgAlgAlts ty _ _) = ty
- get_ty (StgPrimAlts ty _ _) = ty
-\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
- = (case alts of
- StgAlgAlts _ alg_alts deflt ->
- mapL (lintAlgAlt scrut_ty) alg_alts `thenL` \ maybe_alt_tys ->
- lintDeflt deflt scrut_ty `thenL` \ maybe_deflt_ty ->
- returnL (maybe_deflt_ty : maybe_alt_tys)
-
- StgPrimAlts _ prim_alts deflt ->
- mapL (lintPrimAlt scrut_ty) prim_alts `thenL` \ maybe_alt_tys ->
- lintDeflt deflt scrut_ty `thenL` \ maybe_deflt_ty ->
- returnL (maybe_deflt_ty : maybe_alt_tys)
- ) `thenL` \ maybe_result_tys ->
+lintStgAlts :: [StgAlt]
+ -> Type -- Type of scrutinee
+ -> LintM (Maybe Type) -- Type of alternatives
+
+lintStgAlts alts scrut_ty
+ = mapL (lintAlt scrut_ty) alts `thenL` \ maybe_result_tys ->
+
-- Check the result types
case catMaybes (maybe_result_tys) of
[] -> returnL Nothing
where
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) ->
+lintAlt scrut_ty (DEFAULT, _, _, rhs)
+ = lintStgExpr rhs
+
+lintAlt scrut_ty (LitAlt lit, _, _, rhs)
+ = checkTys (literalType lit) scrut_ty (mkAltMsg1 scrut_ty) `thenL_`
+ lintStgExpr rhs
+
+lintAlt scrut_ty (DataAlt con, args, _, rhs)
+ = (case splitTyConApp_maybe scrut_ty of
+ Just (tycon, tys_applied) | isAlgTyCon tycon &&
+ not (isNewTyCon tycon) ->
let
- arg_tys = dataConArgTys con tys_applied
+ cons = tyConDataCons tycon
+ arg_tys = dataConInstArgTys 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 (mkAltMsg1 scrut_ty)
) `thenL_`
addInScopeVars args (
lintStgExpr rhs
-- We give it its own copy, so it isn't overloaded.
elem _ [] = False
elem x (y:ys) = x==y || elem x ys
-
-lintPrimAlt scrut_ty alt@(lit,rhs)
- = checkTys (literalType lit) scrut_ty (mkPrimAltMsg alt) `thenL_`
- lintStgExpr rhs
-
-lintDeflt StgNoDefault scrut_ty = returnL Nothing
-lintDeflt deflt@(StgBindDefault rhs) scrut_ty = lintStgExpr rhs
\end{code}
\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
| BodyOfLetRec [Id] -- One of the binders
dumpLoc (RhsOf v) =
- (getSrcLoc v, ptext SLIT(" [RHS of ") <> pp_binders [v] <> char ']' )
+ (srcLocSpan (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 ']' )
+ (srcLocSpan (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 ']' )
+ (srcLocSpan (getSrcLoc (head bs)), ptext SLIT(" [in body of letrec with binders ") <> pp_binders bs <> char ']' )
pp_binders :: [Id] -> SDoc
if isEmptyBag errs then
Nothing
else
- Just (pprBagOfErrors errs)
+ Just (vcat (punctuate (text "") (bagToList errs)))
}
returnL :: a -> LintM a
(Nothing, errs2) -> (Nothing, errs2)
(Just r, errs2) -> k r loc scope errs2
-thenMaybeL_ :: LintM (Maybe a) -> LintM (Maybe b) -> LintM (Maybe b)
-thenMaybeL_ m k loc scope errs
- = case m loc scope errs of
- (Nothing, errs2) -> (Nothing, errs2)
- (Just _, errs2) -> k loc scope errs2
-
mapL :: (a -> LintM b) -> [a] -> LintM [b]
mapL f [] = returnL []
mapL f (x:xs)
addErrL :: Message -> LintM ()
addErrL msg loc scope errs = ((), addErr errs msg loc)
-addErr :: Bag ErrMsg -> Message -> [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:_) = let (l,hdr) = dumpLoc loc in addErrLocHdrLine l hdr msg
- mk_msg [] = dontAddErrLoc "" msg
+ mk_msg (loc:_) = let (l,hdr) = dumpLoc loc
+ in mkLocMessage l (hdr $$ msg)
+ mk_msg [] = msg
addLoc :: LintLocInfo -> LintM a -> LintM a
addLoc extra_loc m loc scope errs
-- a real error out of it...
let
new_set = mkVarSet ids
-
- shadowed = scope `intersectVarSet` new_set
in
-- After adding -fliberate-case, Simon decided he likes shadowed
-- names after all. WDP 94/07
m loc (scope `unionVarSet` new_set) errs
\end{code}
+Checking function applications: we only check that the type has the
+right *number* of arrows, we don't actually compare the types. This
+is because we can't expect the types to be equal - the type
+applications and type lambdas that we use to calculate accurate types
+have long since disappeared.
+
\begin{code}
checkFunApp :: Type -- The function type
-> [Type] -- The arg type(s)
checkFunApp fun_ty arg_tys msg loc scope errs
= cfa res_ty expected_arg_tys arg_tys
where
- (expected_arg_tys, res_ty) = splitFunTys fun_ty
+ (expected_arg_tys, res_ty) = splitFunTys (dropForAlls fun_ty)
cfa res_ty expected [] -- Args have run out; that's fine
= (Just (mkFunTys expected res_ty), errs)
(new_expected, new_res) -> cfa new_res new_expected arg_tys
cfa res_ty (expected_arg_ty:expected_arg_tys) (arg_ty:arg_tys)
- = if (expected_arg_ty == arg_ty)
- then cfa res_ty expected_arg_tys arg_tys
- else (Nothing, addErr errs msg loc) -- Arg mis-match
+ = cfa res_ty expected_arg_tys arg_tys
\end{code}
\begin{code}
checkInScope :: Id -> LintM ()
checkInScope id loc scope errs
- = if isLocallyDefined id && not (id `elemVarSet` scope) then
+ = if isLocalId id && not (id `elemVarSet` scope) then
((), addErr errs (hsep [ppr id, ptext SLIT("is out of scope")]) loc)
else
((), errs)
checkTys :: Type -> Type -> Message -> LintM ()
checkTys ty1 ty2 msg loc scope errs
- = if (ty1 == ty2)
- then ((), errs)
- else ((), addErr errs msg loc)
+ = -- if (ty1 == ty2) then
+ ((), errs)
+ -- else ((), addErr errs msg loc)
\end{code}
\begin{code}
-mkCaseAltMsg :: StgCaseAlts -> Message
+mkCaseAltMsg :: [StgAlt] -> Message
mkCaseAltMsg alts
= ($$) (text "In some case alternatives, type of alternatives not all same:")
- -- LATER: (ppr alts)
- (panic "mkCaseAltMsg")
-
-mkCaseDataConMsg :: StgExpr -> Message
-mkCaseDataConMsg expr
- = ($$) (ptext SLIT("A case scrutinee not a type-constructor type:"))
- (ppr expr)
-
-mkCaseAbstractMsg :: TyCon -> Message
-mkCaseAbstractMsg tycon
- = ($$) (ptext SLIT("An algebraic case on an abstract type:"))
- (ppr tycon)
+ (empty) -- LATER: ppr alts
mkDefltMsg :: Id -> Message
mkDefltMsg bndr
hang (ptext SLIT("Constructor type:")) 4 (ppr fun_ty),
hang (ptext SLIT("Arg types:")) 4 (vcat (map (ppr) arg_tys))]
-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 -> Message
-mkAlgAltMsg1 ty
- = ($$) (text "In some case statement, type of scrutinee is not a data type:")
- (ppr ty)
+mkAltMsg1 :: Type -> Message
+mkAltMsg1 ty
+ = ($$) (text "In a case expression, type of scrutinee does not match patterns")
+ (ppr ty)
mkAlgAltMsg2 :: Type -> DataCon -> Message
mkAlgAltMsg2 ty con
ppr arg
]
-mkPrimAltMsg :: (Literal, StgExpr) -> Message
-mkPrimAltMsg alt
- = text "In a primitive case alternative, type of literal doesn't match type of scrutinee:"
- $$ ppr alt
+mkCaseOfCaseMsg :: StgExpr -> Message
+mkCaseOfCaseMsg e
+ = text "Case of non-tail-call:" $$ ppr e
mkRhsMsg :: Id -> Type -> Message
mkRhsMsg binder ty