%
-% (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}
-#include "HsVersions.h"
-
module CoreLint (
lintCoreBindings,
- lintUnfolding
+ lintUnfolding,
+ showPass, endPass
) where
-IMP_Ubiq()
+#include "HsVersions.h"
-import CmdLineOpts ( opt_PprUserLength )
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,
- dataConArgTys, GenId{-instances-},
- emptyIdSet, mkIdSet, intersectIdSets,
- unionIdSets, elementOfIdSet, SYN_IE(IdSet),
- SYN_IE(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 Outputable ( PprStyle(..), Outputable(..) )
-import PprType ( GenType, GenTyVar, TyCon )
-import Pretty
-import PrimOp ( primOpType, PrimOp(..) )
-import PrimRep ( PrimRep(..) )
-import SrcLoc ( SrcLoc )
-import Type ( mkFunTy,getFunTy_maybe,mkForAllTy,mkForAllTys,getForAllTy_maybe,
- getFunTyExpandingDicts_maybe,
- getForAllTyExpandingDicts_maybe,
- isPrimType,typeKind,instantiateTy,splitSigmaTy,
- mkForAllUsageTy,getForAllUsageTy,instantiateUsage,
- maybeAppDataTyConExpandingDicts, eqTy, SYN_IE(Type)
+import ErrUtils ( 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 ( tyVarKind, GenTyVar{-instances-} )
-import Unique ( Unique )
-import Usage ( GenUsage, SYN_IE(Usage) )
-import Util ( zipEqual, pprTrace, pprPanic, assertPanic, panic )
+import TyCon ( isPrimTyCon )
+import BasicTypes ( RecFlag(..), isNonRec )
+import CmdLineOpts
+import Maybe
+import Outputable
-infixr 9 `thenL`, `seqL`, `thenMaybeL`, `seqMaybeL`
+import IO ( hPutStrLn, stderr )
+
+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}
%* *
%************************************************************************
--
-- * Oversaturated type app after specialisation (eta reduction
-- may well be happening...);
- --
- -- Note: checkTyApp is usually followed by a call to checkSpecTyApp.
- --
\begin{code}
-lintCoreBindings
- :: PprStyle -> String -> Bool -> [CoreBinding] -> [CoreBinding]
-
-lintCoreBindings sty whoDunnit spec_done binds
- = case (initL (lint_binds binds) spec_done) of
- Nothing -> binds
- Just msg ->
- pprPanic "" (vcat [
- text ("*** Core Lint Errors: in " ++ whoDunnit ++ " ***"),
- msg sty,
- ptext SLIT("*** Offending Program ***"),
- vcat (map (pprCoreBinding sty) binds),
- ptext SLIT("*** End of Offense ***")
- ])
+lintCoreBindings :: DynFlags -> String -> [CoreBind] -> IO ()
+
+lintCoreBindings dflags whoDunnit binds
+ | not (dopt Opt_DoCoreLinting dflags)
+ = return ()
+
+lintCoreBindings dflags whoDunnit binds
+ = case (initL (lint_binds binds)) of
+ Nothing -> showPass dflags ("Core Linted result of " ++ whoDunnit)
+ 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)
+
+ display bad_news
+ = vcat [ text ("*** Core Lint Errors: in result of " ++ whoDunnit ++ " ***"),
+ bad_news,
+ ptext SLIT("*** Offending Program ***"),
+ pprCoreBindings binds,
+ ptext SLIT("*** End of Offense ***")
+ ]
\end{code}
%************************************************************************
(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 (PprForUser opt_PprUserLength),
- ptext SLIT("*** Bad unfolding ***"),
- ppr PprDebug 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}
%************************************************************************
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]
+lintSingleBinding rec_flag (binder,rhs)
+ = addLoc (RhsOf binder) $
-lintCoreBinding (Rec pairs)
- = addInScopeVars binders (
- mapL lintSingleBinding pairs `seqL` returnL binders
- )
- where
- binders = [b | (b,_) <- pairs]
-
-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 isPrimType)
- checkIfSpecDoneL (not (isPrimType (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}
%************************************************************************
%************************************************************************
\begin{code}
-lintCoreExpr :: CoreExpr -> LintM (Maybe Type) -- Nothing if error found
-
-lintCoreExpr (Var var) = 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}
%************************************************************************
%* *
%************************************************************************
-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 (getFunTyExpandingDicts_maybe False{-no peeking in newtypes-} ty) of
- Just (arg,res) | (lit_ty `eqTy` 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 (getFunTyExpandingDicts_maybe False{-as above-} ty) of
- Just (arg,res) | (var_ty `eqTy` 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 (getForAllTyExpandingDicts_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
-- error :: forall a:*. String -> a
-- and then apply it to both boxed and unboxed types.
then
- returnL(Just(instantiateTy [(tyvar,arg_ty)] body))
+ returnL (substTyWith [tyvar] [arg_ty] body)
else
- pprTrace "lintCoreArg:kinds:" (hsep [ppr PprDebug tyvar_kind, ppr PprDebug argty_kind]) $
- addErrL (mkTyAppMsg SLIT("Kinds not right in") ty arg_ty e) `seqL` returnL Nothing
-
-lintCoreArg e ty (UsageArg u)
- = -- ToDo: Check that usage has no unbound usage variables
- case (getForAllUsageTy ty) of
- Just (uvar,bounds,body) ->
- -- ToDo: Check argument satisfies bounds
- returnL(Just(panic "lintCoreArg:instantiateUsage uvar u body"))
- _ -> addErrL (mkUsageAppMsg ty u 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}
%************************************************************************
\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 maybeAppDataTyConExpandingDicts 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}
%************************************************************************
\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)
-
-type ErrMsg = PprStyle -> Doc
+ -> 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 sty (RhsOf v)
- = hcat [ppr sty (getSrcLoc v), ptext SLIT(": [RHS of "), pp_binders sty [v], char ']']
-
- ppr sty (LambdaBodyOf b)
- = hcat [ppr sty (getSrcLoc b),
- ptext SLIT(": [in body of lambda with binder "), pp_binder sty b, char ']']
-
- ppr sty (BodyOfLetRec bs)
- = hcat [ppr sty (getSrcLoc (head bs)),
- ptext SLIT(": [in body of letrec with binders "), pp_binders sty bs, char ']']
-
- ppr sty (ImportedUnfolding locn)
- = (<>) (ppr sty locn) (ptext SLIT(": [in an imported unfolding]"))
-
-pp_binders :: PprStyle -> [Id] -> Doc
-pp_binders sty bs = sep (punctuate comma (map (pp_binder sty) bs))
-
-pp_binder :: PprStyle -> Id -> Doc
-pp_binder sty b = hsep [ppr sty b, text "::", ppr sty (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 ( \ sty ->
- vcat [ msg sty | msg <- 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 []
= 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 ()
-
-addErrL :: ErrMsg -> LintM ()
-addErrL msg spec loc scope errs = ((), addErr errs msg loc)
+checkL :: Bool -> Message -> LintM ()
+checkL True msg = nopL
+checkL False msg = addErrL msg
-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` ( \ sty ->
- hang (ppr sty (head locs)) 4 (msg sty)
- )
+ = 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 PprDebug (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 (\sty -> hsep [ppr sty 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 `eqTy` 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}
+dumpLoc (RhsOf v)
+ = (getSrcLoc v, brackets (ptext SLIT("RHS of") <+> pp_binders [v]))
+
+dumpLoc (LambdaBodyOf b)
+ = (getSrcLoc b, brackets (ptext SLIT("in body of lambda with binder") <+> pp_binder b))
+
+dumpLoc (BodyOfLetRec [])
+ = (noSrcLoc, brackets (ptext SLIT("In body of a letrec with no binders")))
+
+dumpLoc (BodyOfLetRec bs@(_:_))
+ = ( getSrcLoc (head bs), brackets (ptext SLIT("in body of letrec with binders") <+> pp_binders bs))
+
+dumpLoc (AnExpr e)
+ = (noSrcLoc, text "In the expression:" <+> ppr e)
+
+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}
-mkConErrMsg e sty
- = ($$) (ptext SLIT("Application of newtype constructor:"))
- (ppr sty e)
-
-mkCoerceErrMsg e sty
- = ($$) (ptext SLIT("Coercion using a datatype constructor:"))
- (ppr sty e)
-
-
-mkCaseAltMsg :: CoreCaseAlts -> ErrMsg
-mkCaseAltMsg alts sty
- = ($$) (ptext SLIT("Type of case alternatives not the same:"))
- (ppr sty alts)
-
-mkCaseDataConMsg :: CoreExpr -> ErrMsg
-mkCaseDataConMsg expr sty
- = ($$) (ptext SLIT("A case scrutinee not of data constructor type:"))
- (pp_expr sty expr)
-
-mkCaseNotPrimMsg :: TyCon -> ErrMsg
-mkCaseNotPrimMsg tycon sty
- = ($$) (ptext SLIT("A primitive case on a non-primitive type:"))
- (ppr sty tycon)
-
-mkCasePrimMsg :: TyCon -> ErrMsg
-mkCasePrimMsg tycon sty
- = ($$) (ptext SLIT("An algebraic case on a primitive type:"))
- (ppr sty tycon)
-
-mkCaseAbstractMsg :: TyCon -> ErrMsg
-mkCaseAbstractMsg tycon sty
- = ($$) (ptext SLIT("An algebraic case on some weird type:"))
- (ppr sty tycon)
-
-mkDefltMsg :: CoreCaseDefault -> ErrMsg
-mkDefltMsg deflt sty
- = ($$) (ptext SLIT("Binder in case default doesn't match type of scrutinee:"))
- (ppr sty deflt)
-
-mkAppMsg :: Type -> Type -> CoreExpr -> ErrMsg
-mkAppMsg fun arg expr sty
- = vcat [ptext SLIT("Argument value doesn't match argument type:"),
- hang (ptext SLIT("Fun type:")) 4 (ppr sty fun),
- hang (ptext SLIT("Arg type:")) 4 (ppr sty arg),
- hang (ptext SLIT("Expression:")) 4 (pp_expr sty expr)]
-
-mkTyAppMsg :: FAST_STRING -> Type -> Type -> CoreExpr -> ErrMsg
-mkTyAppMsg msg ty arg expr sty
- = vcat [hsep [ptext msg, ptext SLIT("type application:")],
- hang (ptext SLIT("Exp type:")) 4 (ppr sty ty),
- hang (ptext SLIT("Arg type:")) 4 (ppr sty arg),
- hang (ptext SLIT("Expression:")) 4 (pp_expr sty expr)]
-
-mkUsageAppMsg :: Type -> Usage -> CoreExpr -> ErrMsg
-mkUsageAppMsg ty u expr sty
- = vcat [ptext SLIT("Illegal usage application:"),
- hang (ptext SLIT("Exp type:")) 4 (ppr sty ty),
- hang (ptext SLIT("Usage exp:")) 4 (ppr sty u),
- hang (ptext SLIT("Expression:")) 4 (pp_expr sty expr)]
-
-mkAlgAltMsg1 :: Type -> ErrMsg
-mkAlgAltMsg1 ty sty
- = ($$) (text "In some case statement, type of scrutinee is not a data type:")
- (ppr sty ty)
--- (($$) (ppr sty ty) (ppr sty (expandTy ty))) -- ToDo: rm
-
-mkAlgAltMsg2 :: Type -> Id -> ErrMsg
-mkAlgAltMsg2 ty con sty
- = vcat [
- text "In some algebraic case alternative, constructor is not a constructor of scrutinee type:",
- ppr sty ty,
- ppr sty con
- ]
+------------------------------------------------------
+-- Messages for case expressions
-mkAlgAltMsg3 :: Id -> [Id] -> ErrMsg
-mkAlgAltMsg3 con alts sty
- = vcat [
- text "In some algebraic case alternative, number of arguments doesn't match constructor:",
- ppr sty con,
- ppr sty alts
- ]
+mkNullAltsMsg :: CoreExpr -> Message
+mkNullAltsMsg e
+ = hang (text "Case expression with no alternatives:")
+ 4 (ppr e)
+
+mkDefaultArgsMsg :: [Var] -> Message
+mkDefaultArgsMsg args
+ = hang (text "DEFAULT case with binders")
+ 4 (ppr args)
+
+mkCaseAltMsg :: CoreExpr -> Message
+mkCaseAltMsg e
+ = hang (text "Type of case alternatives not the same:")
+ 4 (ppr e)
+
+mkScrutMsg :: Id -> Type -> Message
+mkScrutMsg var scrut_ty
+ = vcat [text "Result binder in case doesn't match scrutinee:" <+> ppr var,
+ text "Result binder type:" <+> ppr (idType var),
+ text "Scrutinee type:" <+> ppr scrut_ty]
-mkAlgAltMsg4 :: Type -> Id -> ErrMsg
-mkAlgAltMsg4 ty arg sty
+
+mkNonDefltMsg e
+ = hang (text "Case expression with DEFAULT not at the beginnning") 4 (ppr e)
+
+nonExhaustiveAltsMsg :: CoreExpr -> Message
+nonExhaustiveAltsMsg e
+ = hang (text "Case expression with non-exhaustive alternatives") 4 (ppr e)
+
+mkBadPatMsg :: Type -> Type -> Message
+mkBadPatMsg con_result_ty scrut_ty
= vcat [
- text "In some algebraic case alternative, type of argument doesn't match data constructor:",
- ppr sty ty,
- ppr sty arg
+ text "In a case alternative, pattern result type doesn't match scrutinee type:",
+ text "Pattern result type:" <+> ppr con_result_ty,
+ text "Scrutinee type:" <+> ppr scrut_ty
]
-mkPrimAltMsg :: (Literal, CoreExpr) -> ErrMsg
-mkPrimAltMsg alt sty
- = ($$)
- (text "In a primitive case alternative, type of literal doesn't match type of scrutinee:")
- (ppr sty alt)
+------------------------------------------------------
+-- Other error messages
-mkRhsMsg :: Id -> Type -> ErrMsg
-mkRhsMsg binder ty sty
+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 -> Message
+mkRhsMsg binder ty
= vcat
[hsep [ptext SLIT("The type of this binder doesn't match the type of its RHS:"),
- ppr sty binder],
- hsep [ptext SLIT("Binder's type:"), ppr sty (idType binder)],
- hsep [ptext SLIT("Rhs type:"), ppr sty ty]]
+ ppr binder],
+ hsep [ptext SLIT("Binder's type:"), ppr (idType binder)],
+ hsep [ptext SLIT("Rhs type:"), ppr ty]]
-mkRhsPrimMsg :: Id -> CoreExpr -> ErrMsg
-mkRhsPrimMsg binder rhs sty
+mkRhsPrimMsg :: Id -> CoreExpr -> Message
+mkRhsPrimMsg binder rhs
= vcat [hsep [ptext SLIT("The type of this binder is primitive:"),
- ppr sty binder],
- hsep [ptext SLIT("Binder's type:"), ppr sty (idType binder)]
+ ppr binder],
+ hsep [ptext SLIT("Binder's type:"), ppr (idType binder)]
]
-mkSpecTyAppMsg :: CoreArg -> ErrMsg
-mkSpecTyAppMsg arg sty
- = ($$)
- (ptext SLIT("Unboxed types in a type application (after specialisation):"))
- (ppr sty 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
+ ]
-pp_expr :: PprStyle -> CoreExpr -> Doc
-pp_expr sty expr
- = pprCoreExpr sty (pprBigCoreBinder sty) (pprTypedCoreBinder sty) (pprTypedCoreBinder sty) expr
+mkStrangeTyMsg e
+ = ptext SLIT("Type where expression expected:") <+> ppr e
\end{code}
projects / ghc-hetmet.git / blobdiff