X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FstgSyn%2FStgLint.lhs;h=f634185c0c68eaaaf1bec00e2771a94732b679e1;hb=398ccea3c0ad773d3950c2497425614430db5b4c;hp=9a70947814b784ea6fdaef4e97759e9bdba0983c;hpb=a6eede3173cee960884e732f40b0998cf84ae015;p=ghc-hetmet.git diff --git a/ghc/compiler/stgSyn/StgLint.lhs b/ghc/compiler/stgSyn/StgLint.lhs index 9a70947..f634185 100644 --- a/ghc/compiler/stgSyn/StgLint.lhs +++ b/ghc/compiler/stgSyn/StgLint.lhs @@ -10,19 +10,21 @@ 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 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, 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 +34,18 @@ 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 +81,7 @@ 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_` @@ -114,6 +128,9 @@ lint_binds_help (binder, rhs) \begin{code} lintStgRhs :: StgRhs -> LintM (Maybe Type) +lintStgRhs (StgRhsClosure _ _ _ _ _ [] expr) + = lintStgExpr expr + lintStgRhs (StgRhsClosure _ _ _ _ _ binders expr) = addLoc (LambdaBodyOf binders) ( addInScopeVars binders ( @@ -127,12 +144,14 @@ 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 +159,31 @@ 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 -> @@ -164,41 +201,40 @@ lintStgExpr (StgLetNoEscape _ _ binds body) 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 () + 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 @@ -208,19 +244,29 @@ lintStgAlts alts scrut_ty case_tycon 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 + 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 (mkAltMsg1 scrut_ty) ) `thenL_` addInScopeVars args ( lintStgExpr rhs @@ -233,13 +279,6 @@ lintAlgAlt scrut_ty (con, args, _, 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} @@ -252,8 +291,8 @@ 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 @@ -284,7 +323,7 @@ initL m if isEmptyBag errs then Nothing else - Just (pprBagOfErrors errs) + Just (vcat (punctuate (text "") (bagToList errs))) } returnL :: a -> LintM a @@ -336,13 +375,14 @@ checkL False msg loc scope errs = ((), addErr errs msg loc) 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 addErrLocHdrLine l hdr msg + mk_msg [] = msg addLoc :: LintLocInfo -> LintM a -> LintM a addLoc extra_loc m loc scope errs @@ -356,8 +396,6 @@ 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 @@ -367,6 +405,12 @@ 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) @@ -376,7 +420,7 @@ checkFunApp :: Type -- The function 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) @@ -393,37 +437,29 @@ 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 -> 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) + (empty) -- LATER: ppr alts mkCaseAbstractMsg :: TyCon -> Message mkCaseAbstractMsg tycon @@ -454,10 +490,10 @@ mkUnappTyMsg var ty (<>) (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 @@ -483,10 +519,9 @@ mkAlgAltMsg4 ty arg 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