X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FstgSyn%2FStgLint.lhs;h=22ef75012eeb0f072b5f99e4863f3fafd90c3e24;hb=32c62212b35b2b631f3753d432b508de5c79c783;hp=b09252df9aaffd9961f84d8e08aa2fd0a2a6a0d8;hpb=7e602b0a11e567fcb035d1afd34015aebcf9a577;p=ghc-hetmet.git diff --git a/ghc/compiler/stgSyn/StgLint.lhs b/ghc/compiler/stgSyn/StgLint.lhs index b09252d..22ef750 100644 --- a/ghc/compiler/stgSyn/StgLint.lhs +++ b/ghc/compiler/stgSyn/StgLint.lhs @@ -10,19 +10,20 @@ module StgLint ( lintStgBindings ) where 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 ) +import TyCon ( TyCon, isAlgTyCon, isNewTyCon, tyConDataCons ) +import Util ( zipEqual, equalLength ) import Outputable infixr 9 `thenL`, `thenL_`, `thenMaybeL`, `thenMaybeL_` @@ -32,6 +33,18 @@ 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} @@ -67,7 +80,7 @@ lintStgBindings whodunnit binds \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_` @@ -76,11 +89,11 @@ lintStgVar v = checkInScope v `thenL_` \begin{code} lintStgBinds :: StgBinding -> LintM [Id] -- Returns the binders -lintStgBinds (StgNonRec binder rhs) +lintStgBinds (StgNonRec _srt binder rhs) = lint_binds_help (binder,rhs) `thenL_` returnL [binder] -lintStgBinds (StgRec pairs) +lintStgBinds (StgRec _srt pairs) = addInScopeVars binders ( mapL lint_binds_help pairs `thenL_` returnL binders @@ -114,7 +127,10 @@ lint_binds_help (binder, rhs) \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 -> @@ -127,12 +143,14 @@ lintStgRhs (StgRhsCon _ con args) 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 -> @@ -140,13 +158,31 @@ lintStgExpr e@(StgApp fun args) 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 -> @@ -166,28 +202,36 @@ lintStgExpr (StgSCC _ expr) = lintStgExpr expr 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 -> @@ -209,18 +253,21 @@ lintStgAlts alts scrut_ty case_tycon 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 @@ -252,24 +299,22 @@ lintDeflt deflt@(StgBindDefault rhs) scrut_ty = 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 @@ -280,13 +325,13 @@ pp_binders bs \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 @@ -331,19 +376,20 @@ mapMaybeL f (x:xs) \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 @@ -358,8 +404,6 @@ addInScopeVars ids 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 @@ -369,16 +413,22 @@ addInScopeVars ids m loc scope errs 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) @@ -395,73 +445,65 @@ checkFunApp fun_ty arg_tys msg loc scope 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:", @@ -469,7 +511,7 @@ mkAlgAltMsg2 ty con 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:", @@ -477,7 +519,7 @@ mkAlgAltMsg3 con alts 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:", @@ -485,12 +527,16 @@ mkAlgAltMsg4 ty arg 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],