diff options
Diffstat (limited to 'compiler/GHC/Tc/Validity.hs')
| -rw-r--r-- | compiler/GHC/Tc/Validity.hs | 20 |
1 files changed, 8 insertions, 12 deletions
diff --git a/compiler/GHC/Tc/Validity.hs b/compiler/GHC/Tc/Validity.hs index cad2ea1796..f7851f21c4 100644 --- a/compiler/GHC/Tc/Validity.hs +++ b/compiler/GHC/Tc/Validity.hs @@ -45,6 +45,7 @@ import GHC.Core.Predicate import GHC.Tc.Types.Origin import GHC.Tc.Types.Rank import GHC.Tc.Errors.Types +import GHC.Types.Error -- others: import GHC.Iface.Type ( pprIfaceType, pprIfaceTypeApp ) @@ -219,7 +220,7 @@ checkAmbiguity ctxt ty ; allow_ambiguous <- xoptM LangExt.AllowAmbiguousTypes ; (_wrap, wanted) <- addErrCtxt (mk_msg allow_ambiguous) $ captureConstraints $ - tcSubTypeSigma ctxt ty ty + tcSubTypeSigma (AmbiguityCheckOrigin ctxt) ctxt ty ty ; simplifyAmbiguityCheck ty wanted ; traceTc "Done ambiguity check for" (ppr ty) } @@ -687,7 +688,8 @@ check_type :: ValidityEnv -> Type -> TcM () -- Rank is allowed rank for function args -- Rank 0 means no for-alls anywhere -check_type _ (TyVarTy _) = return () +check_type _ (TyVarTy _) + = return () check_type ve (AppTy ty1 ty2) = do { check_type ve ty1 @@ -1079,19 +1081,11 @@ check_pred_help under_syn env dflags ctxt pred -- is wrong. For user written signatures, it'll be rejected by kind-checking -- well before we get to validity checking. For inferred types we are careful -- to box such constraints in GHC.Tc.Utils.TcType.pickQuantifiablePreds, as described - -- in Note [Lift equality constraints when quantifying] in GHC.Tc.Utils.TcType + -- in Note [Lift equality constraints when quantifying] in GHC.Tc.Solver ForAllPred _ theta head -> check_quant_pred env dflags ctxt pred theta head _ -> return () -check_eq_pred :: TidyEnv -> DynFlags -> PredType -> TcM () -check_eq_pred env dflags pred - = -- Equational constraints are valid in all contexts if type - -- families are permitted - checkTcM (xopt LangExt.TypeFamilies dflags - || xopt LangExt.GADTs dflags) - (env, TcRnIllegalEqualConstraints (tidyType env pred)) - check_quant_pred :: TidyEnv -> DynFlags -> UserTypeCtxt -> PredType -> ThetaType -> PredType -> TcM () check_quant_pred env dflags ctxt pred theta head_pred @@ -1141,7 +1135,9 @@ check_class_pred :: TidyEnv -> DynFlags -> UserTypeCtxt check_class_pred env dflags ctxt pred cls tys | isEqPredClass cls -- (~) and (~~) are classified as classes, -- but here we want to treat them as equalities - = check_eq_pred env dflags pred + = -- Equational constraints are valid in all contexts, and + -- we do not need to check e.g. for FlexibleContexts here, so just do nothing + return () | isIPClass cls = do { check_arity |