\section[StgLint]{A ``lint'' pass to check for Stg correctness}
\begin{code}
-{-# OPTIONS -w #-}
--- The above warning supression flag is a temporary kludge.
--- While working on this module you are encouraged to remove it and fix
--- any warnings in the module. See
--- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
--- for details
-
module StgLint ( lintStgBindings ) where
import StgSyn
import Maybes
import Name ( getSrcLoc )
import ErrUtils ( Message, mkLocMessage )
-import Type ( mkFunTys, splitFunTys, splitTyConApp_maybe,
- isUnLiftedType, isTyVarTy, dropForAlls, Type
+import TypeRep
+import Type ( mkFunTys, splitFunTy_maybe, splitTyConApp_maybe,
+ isUnLiftedType, isTyVarTy, dropForAlls
)
import TyCon ( isAlgTyCon, isNewTyCon, tyConDataCons )
import Util ( zipEqual, equalLength )
-import SrcLoc ( srcLocSpan )
+import SrcLoc
import Outputable
import FastString
import Control.Monad
lintStgArg :: StgArg -> LintM (Maybe Type)
lintStgArg (StgLitArg lit) = return (Just (literalType lit))
lintStgArg (StgVarArg v) = lintStgVar v
+lintStgArg a = pprPanic "lintStgArg" (ppr a)
+lintStgVar :: Id -> LintM (Maybe Kind)
lintStgVar v = do checkInScope v
return (Just (idType v))
\end{code}
where
binders = [b | (b,_) <- pairs]
+lint_binds_help :: (Id, StgRhs) -> LintM ()
lint_binds_help (binder, rhs)
= addLoc (RhsOf binder) $ do
-- Check the rhs
lintStgExpr (StgOpApp (StgFCallOp _ _) args res_ty) = runMaybeT $ do
-- We don't have enough type information to check
-- the application; ToDo
- maybe_arg_tys <- mapM (MaybeT . lintStgArg) args
+ _maybe_arg_tys <- mapM (MaybeT . lintStgArg) args
return res_ty
lintStgExpr e@(StgOpApp (StgPrimOp op) args _) = runMaybeT $ do
lintStgExpr (StgSCC _ expr) = lintStgExpr expr
lintStgExpr e@(StgCase scrut _ _ bndr _ alts_type alts) = runMaybeT $ do
- MaybeT $ lintStgExpr scrut
+ _ <- MaybeT $ lintStgExpr scrut
MaybeT $ liftM Just $
case alts_type of
UbxTupAlt tc -> check_bndr tc
PolyAlt -> return ()
- MaybeT $ trace (showSDoc (ppr e)) $ do
+ MaybeT $ do
-- we only allow case of tail-call or primop.
case scrut of
StgApp _ _ -> return ()
Just (bndr_tc, _) -> checkL (tc == bndr_tc) bad_bndr
Nothing -> addErrL bad_bndr
+lintStgExpr e = pprPanic "lintStgExpr" (ppr e)
lintStgAlts :: [StgAlt]
-> Type -- Type of scrutinee
where
check ty = checkTys first_ty ty (mkCaseAltMsg alts)
+lintAlt :: Type -> (AltCon, [Id], [Bool], StgExpr) -> LintM (Maybe Type)
lintAlt _ (DEFAULT, _, _, rhs)
= lintStgExpr rhs
| LambdaBodyOf [Id] -- The lambda-binder
| BodyOfLetRec [Id] -- One of the binders
+dumpLoc :: LintLocInfo -> (SrcSpan, SDoc)
dumpLoc (RhsOf v) =
(srcLocSpan (getSrcLoc v), ptext (sLit " [RHS of ") <> pp_binders [v] <> char ']' )
dumpLoc (LambdaBodyOf bs) =
if isEmptyBag errs then
Nothing
else
- Just (vcat (punctuate (text "") (bagToList errs)))
+ Just (vcat (punctuate blankLine (bagToList errs)))
}
instance Monad LintM where
checkFunApp fun_ty arg_tys msg = LintM checkFunApp'
where
checkFunApp' loc _scope errs
- = cfa res_ty expected_arg_tys arg_tys
+ = cfa fun_ty arg_tys
where
- (expected_arg_tys, res_ty) = splitFunTys (dropForAlls fun_ty)
+ cfa fun_ty [] -- Args have run out; that's fine
+ = (Just fun_ty, errs)
- cfa res_ty expected [] -- Args have run out; that's fine
- = (Just (mkFunTys expected res_ty), errs)
+ cfa fun_ty (_:arg_tys)
+ | Just (_arg_ty, res_ty) <- splitFunTy_maybe (dropForAlls fun_ty)
+ = cfa res_ty arg_tys
- cfa res_ty [] arg_tys -- Expected arg tys ran out first;
- -- first see if res_ty is a tyvar template;
- -- otherwise, maybe res_ty is a
- -- dictionary type which is actually a function?
- | isTyVarTy res_ty
- = (Just res_ty, errs)
+ | isTyVarTy fun_ty -- Expected arg tys ran out first;
+ = (Just fun_ty, errs) -- first see if fun_ty is a tyvar template;
+ -- otherwise, maybe fun_ty is a
+ -- dictionary type which is actually a function?
| otherwise
- = case splitFunTys res_ty of
- ([], _) -> (Nothing, addErr errs msg loc) -- Too many args
- (new_expected, new_res) -> cfa new_res new_expected arg_tys
-
- cfa res_ty (_:expected_arg_tys) (_:arg_tys)
- = cfa res_ty expected_arg_tys arg_tys
+ = (Nothing, addErr errs msg loc) -- Too many args
\end{code}
\begin{code}
((), errs)
checkTys :: Type -> Type -> Message -> LintM ()
-checkTys ty1 ty2 msg = LintM $ \loc scope errs
+checkTys _ty1 _ty2 _msg = LintM $ \_loc _scope errs
-> -- if (ty1 == ty2) then
((), errs)
-- else ((), addErr errs msg loc)
\begin{code}
mkCaseAltMsg :: [StgAlt] -> Message
-mkCaseAltMsg alts
+mkCaseAltMsg _alts
= ($$) (text "In some case alternatives, type of alternatives not all same:")
(empty) -- LATER: ppr alts
mkDefltMsg :: Id -> Message
-mkDefltMsg bndr
+mkDefltMsg _bndr
= ($$) (ptext (sLit "Binder of a case expression doesn't match type of scrutinee:"))
(panic "mkDefltMsg")
hsep [ptext (sLit "Rhs type:"), ppr ty]
]
+mkUnLiftedTyMsg :: Id -> StgRhs -> SDoc
mkUnLiftedTyMsg binder rhs
= (ptext (sLit "Let(rec) binder") <+> quotes (ppr binder) <+>
ptext (sLit "has unlifted type") <+> quotes (ppr (idType binder)))