diff options
Diffstat (limited to 'compiler/GHC/Core/Lint.hs')
| -rw-r--r-- | compiler/GHC/Core/Lint.hs | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/compiler/GHC/Core/Lint.hs b/compiler/GHC/Core/Lint.hs index 2f7ab56b5b..2465a2ffdf 100644 --- a/compiler/GHC/Core/Lint.hs +++ b/compiler/GHC/Core/Lint.hs @@ -1021,6 +1021,9 @@ lintIdOcc var nargs ; checkDeadIdOcc var ; checkJoinOcc var nargs + ; case isDataConId_maybe var of + Nothing -> return () + Just dc -> checkTypeDataConOcc "expression" dc ; usage <- varCallSiteUsage var @@ -1107,6 +1110,13 @@ checkJoinOcc var n_args | otherwise = return () +checkTypeDataConOcc :: String -> DataCon -> LintM () +-- Check that the Id is not a data constructor of a `type data` declaration +-- Invariant (I1) of Note [Type data declarations] in GHC.Rename.Module +checkTypeDataConOcc what dc + = checkL (not (isTypeDataTyCon (dataConTyCon dc))) $ + (text "type data constructor found in a" <+> text what <> colon <+> ppr dc) + -- | This function checks that we are able to perform eta expansion for -- functions with no binding, in order to satisfy invariant I3 -- from Note [Representation polymorphism invariants] in GHC.Core. @@ -1561,10 +1571,11 @@ lintCoreAlt case_bndr scrut_ty _scrut_mult alt_ty alt@(Alt (DataAlt con) args rh = zeroUE <$ addErrL (mkNewTyDataConAltMsg scrut_ty alt) | Just (tycon, tycon_arg_tys) <- splitTyConApp_maybe scrut_ty = addLoc (CaseAlt alt) $ do - { -- First instantiate the universally quantified - -- type variables of the data constructor - -- We've already check - lintL (tycon == dataConTyCon con) (mkBadConMsg tycon con) + { checkTypeDataConOcc "pattern" con + ; lintL (tycon == dataConTyCon con) (mkBadConMsg tycon con) + + -- Instantiate the universally quantified + -- type variables of the data constructor ; let { con_payload_ty = piResultTys (dataConRepType con) tycon_arg_tys ; binderMult (Named _) = ManyTy ; binderMult (Anon st _) = scaledMult st |