X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FcoreSyn%2FCoreLint.lhs;h=15146ec4ecf06652895e14c7ce8f53b4629d36da;hb=6b1119bd56511dbf4563efddcd485893f3bff8bf;hp=d4dffadb7849445a69470fa65bfc996ea469dc80;hpb=9dd6e1c216993624a2cd74b62ca0f0569c02c26b;p=ghc-hetmet.git diff --git a/ghc/compiler/coreSyn/CoreLint.lhs b/ghc/compiler/coreSyn/CoreLint.lhs index d4dffad..15146ec 100644 --- a/ghc/compiler/coreSyn/CoreLint.lhs +++ b/ghc/compiler/coreSyn/CoreLint.lhs @@ -1,57 +1,84 @@ % -% (c) The GRASP/AQUA Project, Glasgow University, 1993-1996 +% (c) The GRASP/AQUA Project, Glasgow University, 1993-1998 % \section[CoreLint]{A ``lint'' pass to check for Core correctness} \begin{code} module CoreLint ( lintCoreBindings, - lintUnfolding + lintUnfolding, + showPass, endPass ) where #include "HsVersions.h" -import IO ( hPutStr, stderr ) +import IO ( hPutStr, hPutStrLn, stdout ) -import CmdLineOpts ( opt_D_show_passes, opt_DoCoreLinting ) import CoreSyn +import CoreFVs ( idFreeVars ) +import CoreUtils ( findDefault, exprOkForSpeculation, coreBindsSize, mkPiType ) import Bag -import Kind ( hasMoreBoxityInfo, Kind{-instance-}, - isTypeKind, isBoxedTypeKind {- TEMP --SOF -} ) -import Literal ( literalType, Literal{-instance-} ) -import Id ( idType, isBottomingId, dataConRepType, isDataCon, isNewCon, isAlgCon, - dataConArgTys, GenId{-instances-}, - emptyIdSet, mkIdSet, intersectIdSets, - unionIdSets, elementOfIdSet, IdSet, - Id - ) -import Maybes ( catMaybes ) -import Name ( isLocallyDefined, getSrcLoc, Name{-instance NamedThing-}, - NamedThing(..) ) +import Literal ( literalType ) +import DataCon ( dataConRepType ) +import Var ( Var, Id, TyVar, idType, tyVarKind, isTyVar, isId, mustHaveLocalBinding ) +import VarSet +import Subst ( substTyWith ) +import Name ( getSrcLoc ) import PprCore -import ErrUtils ( doIfSet, ghcExit ) -import PprType ( GenType, GenTyVar, TyCon ) -import PrimOp ( primOpType, PrimOp(..) ) -import PrimRep ( PrimRep(..) ) -import SrcLoc ( SrcLoc ) -import Type ( mkFunTy, splitFunTy_maybe, mkForAllTy, - splitForAllTy_maybe, - isUnpointedType, typeKind, instantiateTy, splitSigmaTy, - splitAlgTyConApp_maybe, Type +import ErrUtils ( doIfSet, dumpIfSet_core, ghcExit, Message, showPass, + addErrLocHdrLine ) +import SrcLoc ( SrcLoc, noSrcLoc ) +import Type ( Type, tyVarsOfType, eqType, + splitFunTy_maybe, mkTyVarTy, + splitForAllTy_maybe, splitTyConApp_maybe, splitTyConApp, + isUnLiftedType, typeKind, + isUnboxedTupleType, + hasMoreBoxityInfo ) -import TyCon ( isPrimTyCon, isDataTyCon ) -import TyVar ( TyVar, tyVarKind, mkTyVarEnv ) -import ErrUtils ( ErrMsg ) -import Unique ( Unique ) -import Util ( zipEqual ) +import TyCon ( isPrimTyCon ) +import BasicTypes ( RecFlag(..), isNonRec ) +import CmdLineOpts +import Maybe +import Util ( notNull ) import Outputable -infixr 9 `thenL`, `seqL`, `thenMaybeL`, `seqMaybeL` +infixr 9 `thenL`, `seqL` \end{code} %************************************************************************ %* * +\subsection{End pass} +%* * +%************************************************************************ + +@showPass@ and @endPass@ don't really belong here, but it makes a convenient +place for them. They print out stuff before and after core passes, +and do Core Lint when necessary. + +\begin{code} +endPass :: DynFlags -> String -> DynFlag -> [CoreBind] -> IO [CoreBind] +endPass dflags pass_name dump_flag binds + = do + -- Report result size if required + -- This has the side effect of forcing the intermediate to be evaluated + if verbosity dflags >= 2 then + hPutStrLn stderr (" Result size = " ++ show (coreBindsSize binds)) + else + return () + + -- Report verbosely, if required + dumpIfSet_core dflags dump_flag pass_name (pprCoreBindings binds) + + -- Type check + lintCoreBindings dflags pass_name binds + + return binds +\end{code} + + +%************************************************************************ +%* * \subsection[lintCoreBindings]{@lintCoreBindings@: Top-level interface} %* * %************************************************************************ @@ -79,33 +106,35 @@ Outstanding issues: -- -- * Oversaturated type app after specialisation (eta reduction -- may well be happening...); - -- - -- Note: checkTyApp is usually followed by a call to checkSpecTyApp. - -- \begin{code} -lintCoreBindings :: String -> Bool -> [CoreBinding] -> IO () +lintCoreBindings :: DynFlags -> String -> [CoreBind] -> IO () -lintCoreBindings whoDunnit spec_done binds - | not opt_DoCoreLinting +lintCoreBindings dflags whoDunnit binds + | not (dopt Opt_DoCoreLinting dflags) = return () -lintCoreBindings whoDunnit spec_done binds - = case (initL (lint_binds binds) spec_done) of - Nothing -> doIfSet opt_D_show_passes - (hPutStr stderr ("*** Core Linted result of " ++ whoDunnit ++ "\n")) - +lintCoreBindings dflags whoDunnit binds + = case (initL (lint_binds binds)) of + Nothing -> done_lint Just bad_news -> printDump (display bad_news) >> ghcExit 1 where - lint_binds [] = returnL () - lint_binds (bind:binds) - = lintCoreBinding bind `thenL` \binders -> - addInScopeVars binders (lint_binds binds) + -- Put all the top-level binders in scope at the start + -- This is because transformation rules can bring something + -- into use 'unexpectedly' + lint_binds binds = addInScopeVars (bindersOfBinds binds) $ + mapL lint_bind binds + + lint_bind (Rec prs) = mapL (lintSingleBinding Recursive) prs `seqL` + returnL () + lint_bind (NonRec bndr rhs) = lintSingleBinding NonRecursive (bndr,rhs) + + done_lint = doIfSet (verbosity dflags >= 2) + (hPutStr stdout ("*** Core Linted result of " ++ whoDunnit ++ "\n")) display bad_news - = vcat [ - text ("*** Core Lint Errors: in result of " ++ whoDunnit ++ " ***"), + = vcat [ text ("*** Core Lint Errors: in result of " ++ whoDunnit ++ " ***"), bad_news, ptext SLIT("*** Offending Program ***"), pprCoreBindings binds, @@ -123,21 +152,15 @@ We use this to check all unfoldings that come in from interfaces (it is very painful to catch errors otherwise): \begin{code} -lintUnfolding :: SrcLoc -> CoreExpr -> Maybe CoreExpr - -lintUnfolding locn expr - = case - (initL (addLoc (ImportedUnfolding locn) (lintCoreExpr expr)) - True{-pretend spec done-}) - of - Nothing -> Just expr - Just msg -> - pprTrace "WARNING: Discarded bad unfolding from interface:\n" - (vcat [msg, - ptext SLIT("*** Bad unfolding ***"), - ppr expr, - ptext SLIT("*** End unfolding ***")]) - Nothing +lintUnfolding :: SrcLoc + -> [Var] -- Treat these as in scope + -> CoreExpr + -> Maybe Message -- Nothing => OK + +lintUnfolding locn vars expr + = initL (addLoc (ImportedUnfolding locn) $ + addInScopeVars vars $ + lintCoreExpr expr) \end{code} %************************************************************************ @@ -149,37 +172,30 @@ lintUnfolding locn expr Check a core binding, returning the list of variables bound. \begin{code} -lintCoreBinding :: CoreBinding -> LintM [Id] - -lintCoreBinding (NonRec binder rhs) - = lintSingleBinding (binder,rhs) `seqL` returnL [binder] - -lintCoreBinding (Rec pairs) - = addInScopeVars binders ( - mapL lintSingleBinding pairs `seqL` returnL binders - ) - where - binders = [b | (b,_) <- pairs] +lintSingleBinding rec_flag (binder,rhs) + = addLoc (RhsOf binder) $ -lintSingleBinding (binder,rhs) - = addLoc (RhsOf binder) ( -- Check the rhs - lintCoreExpr rhs + lintCoreExpr rhs `thenL` \ ty -> - `thenL` \maybe_ty -> -- Check match to RHS type - (case maybe_ty of - Nothing -> returnL () - Just ty -> checkTys (idType binder) ty (mkRhsMsg binder ty)) - - `seqL` - -- Check (not isUnpointedType) - checkIfSpecDoneL (not (isUnpointedType (idType binder))) - (mkRhsPrimMsg binder rhs) - + lintBinder binder `seqL` + checkTys binder_ty ty (mkRhsMsg binder ty) `seqL` + + -- Check (not isUnLiftedType) (also checks for bogus unboxed tuples) + checkL (not (isUnLiftedType binder_ty) + || (isNonRec rec_flag && exprOkForSpeculation rhs)) + (mkRhsPrimMsg binder rhs) `seqL` + + -- Check whether binder's specialisations contain any out-of-scope variables + mapL (checkBndrIdInScope binder) bndr_vars `seqL` + returnL () + -- We should check the unfolding, if any, but this is tricky because -- the unfolding is a SimplifiableCoreExpr. Give up for now. - ) + where + binder_ty = idType binder + bndr_vars = varSetElems (idFreeVars binder) \end{code} %************************************************************************ @@ -189,67 +205,79 @@ lintSingleBinding (binder,rhs) %************************************************************************ \begin{code} -lintCoreExpr :: CoreExpr -> LintM (Maybe Type) -- Nothing if error found - -lintCoreExpr (Var var) - | isAlgCon var = returnL (Just (idType var)) - -- Micro-hack here... Class decls generate applications of their - -- dictionary constructor, but don't generate a binding for the - -- constructor (since it would never be used). After a single round - -- of simplification, these dictionary constructors have been - -- inlined (from their UnfoldInfo) to CoCons. Just between - -- desugaring and simplfication, though, they appear as naked, unbound - -- variables as the function in an application. - -- The hack here simply doesn't check for out-of-scope-ness for - -- data constructors (at least, in a function position). - - | otherwise = checkInScope var `seqL` returnL (Just (idType var)) - -lintCoreExpr (Lit lit) = returnL (Just (literalType lit)) -lintCoreExpr (SCC _ expr) = lintCoreExpr expr -lintCoreExpr e@(Coerce coercion ty expr) - = lintCoercion e coercion `seqL` - lintCoreExpr expr `seqL` returnL (Just ty) - -lintCoreExpr (Let binds body) - = lintCoreBinding binds `thenL` \binders -> - if (null binders) then - lintCoreExpr body -- Can't add a new source location - else - addLoc (BodyOfLetRec binders) - (addInScopeVars binders (lintCoreExpr body)) - -lintCoreExpr e@(Con con args) - = checkL (isDataCon con) (mkConErrMsg e) `seqL` - lintCoreArgs {-False-} e (dataConRepType con) args - -- Note: we don't check for primitive types in these arguments - -lintCoreExpr e@(Prim op args) - = lintCoreArgs {-True-} e (primOpType op) args - -- Note: we do check for primitive types in these arguments - -lintCoreExpr e@(App fun@(Var v) arg) | isBottomingId v - = lintCoreExpr fun `thenMaybeL` \ ty -> lintCoreArg {-False-} e ty arg - -- Note: we don't check for primitive types in argument to 'error' +lintCoreExpr :: CoreExpr -> LintM Type + +lintCoreExpr (Var var) = checkIdInScope var `seqL` returnL (idType var) +lintCoreExpr (Lit lit) = returnL (literalType lit) + +lintCoreExpr (Note (Coerce to_ty from_ty) expr) + = lintCoreExpr expr `thenL` \ expr_ty -> + lintTy to_ty `seqL` + lintTy from_ty `seqL` + checkTys from_ty expr_ty (mkCoerceErr from_ty expr_ty) `seqL` + returnL to_ty + +lintCoreExpr (Note other_note expr) + = lintCoreExpr expr + +lintCoreExpr (Let (NonRec bndr rhs) body) + = lintSingleBinding NonRecursive (bndr,rhs) `seqL` + addLoc (BodyOfLetRec [bndr]) + (addInScopeVars [bndr] (lintCoreExpr body)) + +lintCoreExpr (Let (Rec pairs) body) + = addInScopeVars bndrs $ + mapL (lintSingleBinding Recursive) pairs `seqL` + addLoc (BodyOfLetRec bndrs) (lintCoreExpr body) + where + bndrs = map fst pairs lintCoreExpr e@(App fun arg) - = lintCoreExpr fun `thenMaybeL` \ty -> lintCoreArg {-True-} e ty arg - -- Note: we do check for primitive types in this argument - -lintCoreExpr (Lam (ValBinder var) expr) - = addLoc (LambdaBodyOf var) - (addInScopeVars [var] - (lintCoreExpr expr `thenMaybeL` \ty -> - returnL (Just (mkFunTy (idType var) ty)))) - -lintCoreExpr (Lam (TyBinder tyvar) expr) - = lintCoreExpr expr `thenMaybeL` \ty -> - returnL (Just(mkForAllTy tyvar ty)) - -- ToDo: Should add in-scope type variable at this point - -lintCoreExpr e@(Case scrut alts) - = lintCoreExpr scrut `thenMaybeL` \ty -> - lintCoreAlts alts ty + = lintCoreExpr fun `thenL` \ ty -> + addLoc (AnExpr e) $ + lintCoreArg ty arg + +lintCoreExpr (Lam var expr) + = addLoc (LambdaBodyOf var) $ + (if isId var then + checkL (not (isUnboxedTupleType (idType var))) (mkUnboxedTupleMsg var) + else + returnL ()) + `seqL` + (addInScopeVars [var] $ + lintCoreExpr expr `thenL` \ ty -> + + returnL (mkPiType var ty)) + +lintCoreExpr e@(Case scrut var alts) + = -- Check the scrutinee + lintCoreExpr scrut `thenL` \ scrut_ty -> + + -- Check the binder + lintBinder var `seqL` + + -- If this is an unboxed tuple case, then the binder must be dead + {- + checkL (if isUnboxedTupleType (idType var) + then isDeadBinder var + else True) (mkUnboxedTupleMsg var) `seqL` + -} + + checkTys (idType var) scrut_ty (mkScrutMsg var scrut_ty) `seqL` + + addInScopeVars [var] ( + + -- Check the alternatives + checkCaseAlts e scrut_ty alts `seqL` + + mapL (lintCoreAlt scrut_ty) alts `thenL` \ (alt_ty : alt_tys) -> + mapL (check alt_ty) alt_tys `seqL` + returnL alt_ty) + where + check alt_ty1 alt_ty2 = checkTys alt_ty1 alt_ty2 (mkCaseAltMsg e) + +lintCoreExpr e@(Type ty) + = addErrL (mkStrangeTyMsg e) \end{code} %************************************************************************ @@ -258,51 +286,49 @@ lintCoreExpr e@(Case scrut alts) %* * %************************************************************************ -The boolean argument indicates whether we should flag type -applications to primitive types as being errors. +The basic version of these functions checks that the argument is a +subtype of the required type, as one would expect. \begin{code} -lintCoreArgs :: {-Bool ->-} CoreExpr -> Type -> [CoreArg] -> LintM (Maybe Type) +lintCoreArgs :: Type -> [CoreArg] -> LintM Type +lintCoreArgs = lintCoreArgs0 checkTys -lintCoreArgs _ ty [] = returnL (Just ty) -lintCoreArgs e ty (a : args) - = lintCoreArg e ty a `thenMaybeL` \ res -> - lintCoreArgs e res args +lintCoreArg :: Type -> CoreArg -> LintM Type +lintCoreArg = lintCoreArg0 checkTys \end{code} -%************************************************************************ -%* * -\subsection[lintCoreArg]{lintCoreArg} -%* * -%************************************************************************ +The primitive version of these functions takes a check argument, +allowing a different comparison. \begin{code} -lintCoreArg :: {-Bool ->-} CoreExpr -> Type -> CoreArg -> LintM (Maybe Type) +lintCoreArgs0 check_tys ty [] = returnL ty +lintCoreArgs0 check_tys ty (a : args) + = lintCoreArg0 check_tys ty a `thenL` \ res -> + lintCoreArgs0 check_tys res args -lintCoreArg e ty (LitArg lit) - = -- Make sure function type matches argument - case (splitFunTy_maybe ty) of - Just (arg,res) | (lit_ty == arg) -> returnL(Just res) - _ -> addErrL (mkAppMsg ty lit_ty e) `seqL` returnL Nothing - where - lit_ty = literalType lit +lintCoreArg0 check_tys ty a@(Type arg_ty) + = lintTy arg_ty `seqL` + lintTyApp ty arg_ty -lintCoreArg e ty (VarArg v) - = -- Make sure variable is bound - checkInScope v `seqL` - -- Make sure function type matches argument - case (splitFunTy_maybe ty) of - Just (arg,res) | (var_ty == arg) -> returnL(Just res) - _ -> addErrL (mkAppMsg ty var_ty e) `seqL` returnL Nothing - where - var_ty = idType v +lintCoreArg0 check_tys fun_ty arg + = -- Make sure function type matches argument + lintCoreExpr arg `thenL` \ arg_ty -> + let + err = mkAppMsg fun_ty arg_ty + in + case splitFunTy_maybe fun_ty of + Just (arg,res) -> check_tys arg arg_ty err `seqL` + returnL res + _ -> addErrL err +\end{code} -lintCoreArg e ty a@(TyArg arg_ty) - = -- ToDo: Check that ty is well-kinded and has no unbound tyvars - case (splitForAllTy_maybe ty) of - Nothing -> addErrL (mkTyAppMsg SLIT("Illegal") ty arg_ty e) `seqL` returnL Nothing +\begin{code} +lintTyApp ty arg_ty + = case splitForAllTy_maybe ty of + Nothing -> addErrL (mkTyAppMsg ty arg_ty) Just (tyvar,body) -> + if not (isTyVar tyvar) then addErrL (mkTyAppMsg ty arg_ty) else let tyvar_kind = tyVarKind tyvar argty_kind = typeKind arg_ty @@ -313,12 +339,20 @@ lintCoreArg e ty a@(TyArg arg_ty) -- error :: forall a:*. String -> a -- and then apply it to both boxed and unboxed types. then - returnL(Just(instantiateTy (mkTyVarEnv [(tyvar,arg_ty)]) body)) + returnL (substTyWith [tyvar] [arg_ty] body) else - pprTrace "lintCoreArg:kinds:" (hsep [ppr tyvar_kind, ppr argty_kind]) $ - addErrL (mkKindErrMsg tyvar arg_ty e) `seqL` returnL Nothing + addErrL (mkKindErrMsg tyvar arg_ty) + +lintTyApps fun_ty [] + = returnL fun_ty + +lintTyApps fun_ty (arg_ty : arg_tys) + = lintTyApp fun_ty arg_ty `thenL` \ fun_ty' -> + lintTyApps fun_ty' arg_tys \end{code} + + %************************************************************************ %* * \subsection[lintCoreAlts]{lintCoreAlts} @@ -326,100 +360,96 @@ lintCoreArg e ty a@(TyArg arg_ty) %************************************************************************ \begin{code} -lintCoreAlts :: CoreCaseAlts - -> Type -- Type of scrutinee --- -> TyCon -- TyCon pinned on the case - -> LintM (Maybe Type) -- Type of alternatives - -lintCoreAlts whole_alts@(AlgAlts alts deflt) ty --tycon - = -- Check tycon is not a primitive tycon --- addErrIfL (isPrimTyCon tycon) (mkCasePrimMsg tycon) --- `seqL` - -- Check we are scrutinising a proper datatype - -- (ToDo: robustify) --- addErrIfL (not (tyConFamilySize tycon >= 1)) (mkCaseAbstractMsg tycon) --- `seqL` - lintDeflt deflt ty - `thenL` \maybe_deflt_ty -> - mapL (lintAlgAlt ty {-tycon-}) alts - `thenL` \maybe_alt_tys -> - -- Check the result types - case catMaybes (maybe_deflt_ty : maybe_alt_tys) of - [] -> returnL Nothing - - (first_ty:tys) -> mapL check tys `seqL` - returnL (Just first_ty) - where - check ty = checkTys first_ty ty (mkCaseAltMsg whole_alts) - -lintCoreAlts whole_alts@(PrimAlts alts deflt) ty --tycon - = -- Check tycon is a primitive tycon --- addErrIfL (not (isPrimTyCon tycon)) (mkCaseNotPrimMsg tycon) --- `seqL` - mapL (lintPrimAlt ty) alts - `thenL` \maybe_alt_tys -> - lintDeflt deflt ty - `thenL` \maybe_deflt_ty -> - -- Check the result types - case catMaybes (maybe_deflt_ty : maybe_alt_tys) of - [] -> returnL Nothing - - (first_ty:tys) -> mapL check tys `seqL` - returnL (Just first_ty) - where - check ty = checkTys first_ty ty (mkCaseAltMsg whole_alts) - -lintAlgAlt scrut_ty (con,args,rhs) - = (case splitAlgTyConApp_maybe scrut_ty of - Just (tycon, tys_applied, cons) | isDataTyCon tycon -> - let - arg_tys = dataConArgTys con tys_applied - in - checkL (con `elem` cons) (mkAlgAltMsg2 scrut_ty con) `seqL` - checkL (length arg_tys == length args) (mkAlgAltMsg3 con args) - `seqL` - mapL check (zipEqual "lintAlgAlt" arg_tys args) `seqL` - returnL () - - other -> addErrL (mkAlgAltMsg1 scrut_ty) - ) `seqL` - addInScopeVars args ( - lintCoreExpr rhs - ) +checkCaseAlts :: CoreExpr -> Type -> [CoreAlt] -> LintM () +-- a) Check that the alts are non-empty +-- b) Check that the DEFAULT comes first, if it exists +-- c) Check that there's a default for infinite types +-- NB: Algebraic cases are not necessarily exhaustive, because +-- the simplifer correctly eliminates case that can't +-- possibly match. + +checkCaseAlts e ty [] + = addErrL (mkNullAltsMsg e) + +checkCaseAlts e ty alts + = checkL (all non_deflt con_alts) (mkNonDefltMsg e) `seqL` + checkL (isJust maybe_deflt || not is_infinite_ty) + (nonExhaustiveAltsMsg e) where - check (ty, arg) = checkTys ty (idType arg) (mkAlgAltMsg4 ty arg) - - -- elem: yes, the elem-list here can sometimes be long-ish, - -- but as it's use-once, probably not worth doing anything different - -- We give it its own copy, so it isn't overloaded. - elem _ [] = False - elem x (y:ys) = x==y || elem x ys - -lintPrimAlt ty alt@(lit,rhs) - = checkTys (literalType lit) ty (mkPrimAltMsg alt) `seqL` - lintCoreExpr rhs - -lintDeflt NoDefault _ = returnL Nothing -lintDeflt deflt@(BindDefault binder rhs) ty - = checkTys (idType binder) ty (mkDefltMsg deflt) `seqL` - addInScopeVars [binder] (lintCoreExpr rhs) + (con_alts, maybe_deflt) = findDefault alts + + non_deflt (DEFAULT, _, _) = False + non_deflt alt = True + + is_infinite_ty = case splitTyConApp_maybe ty of + Nothing -> False + Just (tycon, tycon_arg_tys) -> isPrimTyCon tycon +\end{code} + +\begin{code} +lintCoreAlt :: Type -- Type of scrutinee + -> CoreAlt + -> LintM Type -- Type of alternatives + +lintCoreAlt scrut_ty alt@(DEFAULT, args, rhs) + = checkL (null args) (mkDefaultArgsMsg args) `seqL` + lintCoreExpr rhs + +lintCoreAlt scrut_ty alt@(LitAlt lit, args, rhs) + = checkL (null args) (mkDefaultArgsMsg args) `seqL` + checkTys lit_ty scrut_ty + (mkBadPatMsg lit_ty scrut_ty) `seqL` + lintCoreExpr rhs + where + lit_ty = literalType lit + +lintCoreAlt scrut_ty alt@(DataAlt con, args, rhs) + = addLoc (CaseAlt alt) ( + + mapL (\arg -> checkL (not (isUnboxedTupleType (idType arg))) + (mkUnboxedTupleMsg arg)) args `seqL` + + addInScopeVars args ( + + -- Check the pattern + -- Scrutinee type must be a tycon applicn; checked by caller + -- This code is remarkably compact considering what it does! + -- NB: args must be in scope here so that the lintCoreArgs line works. + -- NB: relies on existential type args coming *after* ordinary type args + case splitTyConApp scrut_ty of { (tycon, tycon_arg_tys) -> + lintTyApps (dataConRepType con) tycon_arg_tys `thenL` \ con_type -> + lintCoreArgs con_type (map mk_arg args) `thenL` \ con_result_ty -> + checkTys con_result_ty scrut_ty (mkBadPatMsg con_result_ty scrut_ty) + } `seqL` + + -- Check the RHS + lintCoreExpr rhs + )) + where + mk_arg b | isTyVar b = Type (mkTyVarTy b) + | isId b = Var b + | otherwise = pprPanic "lintCoreAlt:mk_arg " (ppr b) \end{code} %************************************************************************ %* * -\subsection[lint-coercion]{Coercion} +\subsection[lint-types]{Types} %* * %************************************************************************ \begin{code} -lintCoercion e (CoerceIn con) = check_con e con -lintCoercion e (CoerceOut con) = check_con e con - -check_con e con = checkL (isNewCon con) - (mkCoerceErrMsg e) +lintBinder :: Var -> LintM () +lintBinder v = nopL +-- ToDo: lint its type +-- ToDo: lint its rules + +lintTy :: Type -> LintM () +lintTy ty = mapL checkIdInScope (varSetElems (tyVarsOfType ty)) `seqL` + returnL () + -- ToDo: check the kind structure of the type \end{code} - + %************************************************************************ %* * \subsection[lint-monad]{The Lint monad} @@ -427,76 +457,43 @@ check_con e con = checkL (isNewCon con) %************************************************************************ \begin{code} -type LintM a = Bool -- True <=> specialisation has been done - -> [LintLocInfo] -- Locations +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 + -> (Maybe 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 + | CaseAlt CoreAlt -- Pattern of a case alternative + | AnExpr CoreExpr -- Some expression | ImportedUnfolding SrcLoc -- Some imported unfolding (ToDo: say which) - -instance Outputable LintLocInfo where - ppr (RhsOf v) - = ppr (getSrcLoc v) <> colon <+> - brackets (ptext SLIT("RHS of") <+> pp_binders [v]) - - ppr (LambdaBodyOf b) - = ppr (getSrcLoc b) <> colon <+> - brackets (ptext SLIT("in body of lambda with binder") <+> pp_binder b) - - ppr (BodyOfLetRec bs) - = ppr (getSrcLoc (head bs)) <> colon <+> - brackets (ptext SLIT("in body of letrec with binders") <+> pp_binders bs) - - ppr (ImportedUnfolding locn) - = ppr locn <> colon <+> - brackets (ptext SLIT("in an imported unfolding")) - -pp_binders :: [Id] -> SDoc -pp_binders bs = sep (punctuate comma (map pp_binder bs)) - -pp_binder :: Id -> SDoc -pp_binder b = hsep [ppr b, text "::", ppr (idType b)] \end{code} \begin{code} -initL :: LintM a -> Bool -> Maybe ErrMsg -initL m spec_done - = case (m spec_done [] emptyIdSet emptyBag) of { (_, errs) -> - if isEmptyBag errs then - Nothing - else - Just (vcat (bagToList errs)) - } +initL :: LintM a -> Maybe Message {- errors -} +initL m + = case m [] emptyVarSet emptyBag of + (_, errs) | isEmptyBag errs -> Nothing + | otherwise -> Just (vcat (punctuate (text "") (bagToList errs))) returnL :: a -> LintM a -returnL r spec loc scope errs = (r, errs) +returnL r loc scope errs = (Just r, errs) + +nopL :: LintM a +nopL loc scope errs = (Nothing, errs) thenL :: LintM a -> (a -> LintM b) -> LintM b -thenL m k spec loc scope errs - = case m spec loc scope errs of - (r, errs') -> k r spec loc scope errs' +thenL m k loc scope errs + = case m loc scope errs of + (Just r, errs') -> k r loc scope errs' + (Nothing, errs') -> (Nothing, errs') seqL :: LintM a -> LintM b -> LintM b -seqL m k spec loc scope errs - = case m spec loc scope errs of - (_, errs') -> k spec loc scope errs' - -thenMaybeL :: LintM (Maybe a) -> (a -> LintM (Maybe b)) -> LintM (Maybe b) -thenMaybeL m k spec loc scope errs - = case m spec loc scope errs of - (Nothing, errs2) -> (Nothing, errs2) - (Just r, errs2) -> k r spec loc scope errs2 - -seqMaybeL :: LintM (Maybe a) -> LintM (Maybe b) -> LintM (Maybe b) -seqMaybeL m k spec loc scope errs - = case m spec loc scope errs of - (Nothing, errs2) -> (Nothing, errs2) - (Just _, errs2) -> k spec loc scope errs2 +seqL m k loc scope errs + = case m loc scope errs of + (_, errs') -> k loc scope errs' mapL :: (a -> LintM b) -> [a] -> LintM [b] mapL f [] = returnL [] @@ -504,179 +501,168 @@ mapL f (x:xs) = f x `thenL` \ r -> mapL f xs `thenL` \ rs -> returnL (r:rs) - -mapMaybeL :: (a -> LintM (Maybe b)) -> [a] -> LintM (Maybe [b]) - -- Returns Nothing if anything fails -mapMaybeL f [] = returnL (Just []) -mapMaybeL f (x:xs) - = f x `thenMaybeL` \ r -> - mapMaybeL f xs `thenMaybeL` \ rs -> - returnL (Just (r:rs)) \end{code} \begin{code} -checkL :: Bool -> ErrMsg -> LintM () -checkL True msg spec loc scope errs = ((), errs) -checkL False msg spec loc scope errs = ((), addErr errs msg loc) - -checkIfSpecDoneL :: Bool -> ErrMsg -> LintM () -checkIfSpecDoneL True msg spec loc scope errs = ((), errs) -checkIfSpecDoneL False msg True loc scope errs = ((), addErr errs msg loc) -checkIfSpecDoneL False msg False loc scope errs = ((), errs) - -addErrIfL pred spec - = if pred then addErrL spec else returnL () +checkL :: Bool -> Message -> LintM () +checkL True msg = nopL +checkL False msg = addErrL msg -addErrL :: ErrMsg -> LintM () -addErrL msg spec loc scope errs = ((), addErr errs msg loc) - -addErr :: Bag ErrMsg -> ErrMsg -> [LintLocInfo] -> Bag ErrMsg +addErrL :: Message -> LintM a +addErrL msg loc scope errs = (Nothing, addErr errs msg loc) +addErr :: Bag Message -> Message -> [LintLocInfo] -> Bag Message addErr errs_so_far msg locs - = ASSERT (not (null locs)) - errs_so_far `snocBag` (hang (ppr (head locs)) 4 msg) + = ASSERT( notNull locs ) + errs_so_far `snocBag` mk_msg msg + where + (loc, cxt1) = dumpLoc (head locs) + cxts = [snd (dumpLoc loc) | loc <- locs] + context | opt_PprStyle_Debug = vcat (reverse cxts) $$ cxt1 + | otherwise = cxt1 + + mk_msg msg = addErrLocHdrLine loc context msg addLoc :: LintLocInfo -> LintM a -> LintM a -addLoc extra_loc m spec loc scope errs - = m spec (extra_loc:loc) scope errs - -addInScopeVars :: [Id] -> LintM a -> LintM a -addInScopeVars ids m spec loc scope errs - = -- We check if these "new" ids are already - -- in scope, i.e., we have *shadowing* going on. - -- For now, it's just a "trace"; we may make - -- a real error out of it... - let - new_set = mkIdSet ids +addLoc extra_loc m loc scope errs + = m (extra_loc:loc) scope errs --- shadowed = scope `intersectIdSets` new_set - in --- After adding -fliberate-case, Simon decided he likes shadowed --- names after all. WDP 94/07 --- (if isEmptyUniqSet shadowed --- then id --- else pprTrace "Shadowed vars:" (ppr (uniqSetToList shadowed))) ( - m spec loc (scope `unionIdSets` new_set) errs --- ) +addInScopeVars :: [Var] -> LintM a -> LintM a +addInScopeVars ids m loc scope errs + = m loc (scope `unionVarSet` mkVarSet ids) errs \end{code} \begin{code} -checkInScope :: Id -> LintM () -checkInScope id spec loc scope errs - = let - id_name = getName id - in - if isLocallyDefined id_name && not (id `elementOfIdSet` scope) then - ((), addErr errs (hsep [ppr id, ptext SLIT("is out of scope")]) loc) - else - ((),errs) - -checkTys :: Type -> Type -> ErrMsg -> LintM () -checkTys ty1 ty2 msg spec loc scope errs - = if ty1 == ty2 then ((), errs) else ((), addErr errs msg loc) +checkIdInScope :: Var -> LintM () +checkIdInScope id + = checkInScope (ptext SLIT("is out of scope")) id + +checkBndrIdInScope :: Var -> Var -> LintM () +checkBndrIdInScope binder id + = checkInScope msg id + where + msg = ptext SLIT("is out of scope inside info for") <+> + ppr binder + +checkInScope :: SDoc -> Var -> LintM () +checkInScope loc_msg var loc scope errs + | mustHaveLocalBinding var && not (var `elemVarSet` scope) + = (Nothing, addErr errs (hsep [ppr var, loc_msg]) loc) + | otherwise + = nopL loc scope errs + +checkTys :: Type -> Type -> Message -> LintM () +-- check ty2 is subtype of ty1 (ie, has same structure but usage +-- annotations need only be consistent, not equal) +checkTys ty1 ty2 msg + | ty1 `eqType` ty2 = nopL + | otherwise = addErrL msg \end{code} + +%************************************************************************ +%* * +\subsection{Error messages} +%* * +%************************************************************************ + \begin{code} -mkConErrMsg e - = ($$) (ptext SLIT("Application of newtype constructor:")) - (ppr e) - -mkCoerceErrMsg e - = ($$) (ptext SLIT("Coercion using a datatype constructor:")) - (ppr e) - - -mkCaseAltMsg :: CoreCaseAlts -> ErrMsg -mkCaseAltMsg alts - = ($$) (ptext SLIT("Type of case alternatives not the same:")) - (ppr alts) - -mkCaseDataConMsg :: CoreExpr -> ErrMsg -mkCaseDataConMsg expr - = ($$) (ptext SLIT("A case scrutinee not of data constructor type:")) - (pprCoreExpr expr) - -mkCaseNotPrimMsg :: TyCon -> ErrMsg -mkCaseNotPrimMsg tycon - = ($$) (ptext SLIT("A primitive case on a non-primitive type:")) - (ppr tycon) - -mkCasePrimMsg :: TyCon -> ErrMsg -mkCasePrimMsg tycon - = ($$) (ptext SLIT("An algebraic case on a primitive type:")) - (ppr tycon) - -mkCaseAbstractMsg :: TyCon -> ErrMsg -mkCaseAbstractMsg tycon - = ($$) (ptext SLIT("An algebraic case on some weird type:")) - (ppr tycon) - -mkDefltMsg :: CoreCaseDefault -> ErrMsg -mkDefltMsg deflt - = ($$) (ptext SLIT("Binder in case default doesn't match type of scrutinee:")) - (ppr deflt) - -mkAppMsg :: Type -> Type -> CoreExpr -> ErrMsg -mkAppMsg fun arg expr - = vcat [ptext SLIT("Argument value doesn't match argument type:"), - hang (ptext SLIT("Fun type:")) 4 (ppr fun), - hang (ptext SLIT("Arg type:")) 4 (ppr arg), - hang (ptext SLIT("Expression:")) 4 (pprCoreExpr expr)] +dumpLoc (RhsOf v) + = (getSrcLoc v, brackets (ptext SLIT("RHS of") <+> pp_binders [v])) -mkKindErrMsg :: TyVar -> Type -> CoreExpr -> ErrMsg -mkKindErrMsg tyvar arg_ty expr - = vcat [ptext SLIT("Kinds don't match in type application:"), - hang (ptext SLIT("Type variable:")) - 4 (ppr tyvar <+> ptext SLIT("::") <+> ppr (tyVarKind tyvar)), - hang (ptext SLIT("Arg type:")) - 4 (ppr arg_ty <+> ptext SLIT("::") <+> ppr (typeKind arg_ty)), - hang (ptext SLIT("Expression:")) 4 (pprCoreExpr expr)] +dumpLoc (LambdaBodyOf b) + = (getSrcLoc b, brackets (ptext SLIT("in body of lambda with binder") <+> pp_binder b)) -mkTyAppMsg :: FAST_STRING -> Type -> Type -> CoreExpr -> ErrMsg -mkTyAppMsg msg ty arg expr - = vcat [hsep [ptext msg, ptext SLIT("type application:")], - hang (ptext SLIT("Exp type:")) - 4 (ppr ty <+> ptext SLIT("::") <+> ppr (typeKind ty)), - hang (ptext SLIT("Arg type:")) - 4 (ppr arg <+> ptext SLIT("::") <+> ppr (typeKind arg)), - hang (ptext SLIT("Expression:")) 4 (pprCoreExpr expr)] +dumpLoc (BodyOfLetRec []) + = (noSrcLoc, brackets (ptext SLIT("In body of a letrec with no binders"))) -mkAlgAltMsg1 :: Type -> ErrMsg -mkAlgAltMsg1 ty - = ($$) (text "In some case statement, type of scrutinee is not a data type:") - (ppr ty) +dumpLoc (BodyOfLetRec bs@(_:_)) + = ( getSrcLoc (head bs), brackets (ptext SLIT("in body of letrec with binders") <+> pp_binders bs)) -mkAlgAltMsg2 :: Type -> Id -> ErrMsg -mkAlgAltMsg2 ty con - = vcat [ - text "In some algebraic case alternative, constructor is not a constructor of scrutinee type:", - ppr ty, - ppr con - ] +dumpLoc (AnExpr e) + = (noSrcLoc, text "In the expression:" <+> ppr e) -mkAlgAltMsg3 :: Id -> [Id] -> ErrMsg -mkAlgAltMsg3 con alts - = vcat [ - text "In some algebraic case alternative, number of arguments doesn't match constructor:", - ppr con, - ppr alts - ] +dumpLoc (CaseAlt (con, args, rhs)) + = (noSrcLoc, text "In a case pattern:" <+> parens (ppr con <+> ppr args)) + +dumpLoc (ImportedUnfolding locn) + = (locn, brackets (ptext SLIT("in an imported unfolding"))) + +pp_binders :: [Var] -> SDoc +pp_binders bs = sep (punctuate comma (map pp_binder bs)) + +pp_binder :: Var -> SDoc +pp_binder b | isId b = hsep [ppr b, dcolon, ppr (idType b)] + | isTyVar b = hsep [ppr b, dcolon, ppr (tyVarKind b)] +\end{code} + +\begin{code} +------------------------------------------------------ +-- Messages for case expressions + +mkNullAltsMsg :: CoreExpr -> Message +mkNullAltsMsg e + = hang (text "Case expression with no alternatives:") + 4 (ppr e) + +mkDefaultArgsMsg :: [Var] -> Message +mkDefaultArgsMsg args + = hang (text "DEFAULT case with binders") + 4 (ppr args) + +mkCaseAltMsg :: CoreExpr -> Message +mkCaseAltMsg e + = hang (text "Type of case alternatives not the same:") + 4 (ppr e) + +mkScrutMsg :: Id -> Type -> Message +mkScrutMsg var scrut_ty + = vcat [text "Result binder in case doesn't match scrutinee:" <+> ppr var, + text "Result binder type:" <+> ppr (idType var), + text "Scrutinee type:" <+> ppr scrut_ty] + + +mkNonDefltMsg e + = hang (text "Case expression with DEFAULT not at the beginnning") 4 (ppr e) -mkAlgAltMsg4 :: Type -> Id -> ErrMsg -mkAlgAltMsg4 ty arg +nonExhaustiveAltsMsg :: CoreExpr -> Message +nonExhaustiveAltsMsg e + = hang (text "Case expression with non-exhaustive alternatives") 4 (ppr e) + +mkBadPatMsg :: Type -> Type -> Message +mkBadPatMsg con_result_ty scrut_ty = vcat [ - text "In some algebraic case alternative, type of argument doesn't match data constructor:", - ppr ty, - ppr arg + text "In a case alternative, pattern result type doesn't match scrutinee type:", + text "Pattern result type:" <+> ppr con_result_ty, + text "Scrutinee type:" <+> ppr scrut_ty ] -mkPrimAltMsg :: (Literal, CoreExpr) -> ErrMsg -mkPrimAltMsg alt - = ($$) - (text "In a primitive case alternative, type of literal doesn't match type of scrutinee:") - (ppr alt) +------------------------------------------------------ +-- Other error messages + +mkAppMsg :: Type -> Type -> Message +mkAppMsg fun arg + = vcat [ptext SLIT("Argument value doesn't match argument type:"), + hang (ptext SLIT("Fun type:")) 4 (ppr fun), + hang (ptext SLIT("Arg type:")) 4 (ppr arg)] + +mkKindErrMsg :: TyVar -> Type -> Message +mkKindErrMsg tyvar arg_ty + = vcat [ptext SLIT("Kinds don't match in type application:"), + hang (ptext SLIT("Type variable:")) + 4 (ppr tyvar <+> dcolon <+> ppr (tyVarKind tyvar)), + hang (ptext SLIT("Arg type:")) + 4 (ppr arg_ty <+> dcolon <+> ppr (typeKind arg_ty))] + +mkTyAppMsg :: Type -> Type -> Message +mkTyAppMsg ty arg_ty + = vcat [text "Illegal type application:", + hang (ptext SLIT("Exp type:")) + 4 (ppr ty <+> dcolon <+> ppr (typeKind ty)), + hang (ptext SLIT("Arg type:")) + 4 (ppr arg_ty <+> dcolon <+> ppr (typeKind arg_ty))] -mkRhsMsg :: Id -> Type -> ErrMsg +mkRhsMsg :: Id -> Type -> Message mkRhsMsg binder ty = vcat [hsep [ptext SLIT("The type of this binder doesn't match the type of its RHS:"), @@ -684,16 +670,24 @@ mkRhsMsg binder ty hsep [ptext SLIT("Binder's type:"), ppr (idType binder)], hsep [ptext SLIT("Rhs type:"), ppr ty]] -mkRhsPrimMsg :: Id -> CoreExpr -> ErrMsg +mkRhsPrimMsg :: Id -> CoreExpr -> Message mkRhsPrimMsg binder rhs = vcat [hsep [ptext SLIT("The type of this binder is primitive:"), ppr binder], hsep [ptext SLIT("Binder's type:"), ppr (idType binder)] ] -mkSpecTyAppMsg :: CoreArg -> ErrMsg -mkSpecTyAppMsg arg - = ($$) - (ptext SLIT("Unboxed types in a type application (after specialisation):")) - (ppr arg) +mkUnboxedTupleMsg :: Id -> Message +mkUnboxedTupleMsg binder + = vcat [hsep [ptext SLIT("A variable has unboxed tuple type:"), ppr binder], + hsep [ptext SLIT("Binder's type:"), ppr (idType binder)]] + +mkCoerceErr from_ty expr_ty + = vcat [ptext SLIT("From-type of Coerce differs from type of enclosed expression"), + ptext SLIT("From-type:") <+> ppr from_ty, + ptext SLIT("Type of enclosed expr:") <+> ppr expr_ty + ] + +mkStrangeTyMsg e + = ptext SLIT("Type where expression expected:") <+> ppr e \end{code}