diff options
Diffstat (limited to 'compiler/GHC/Tc/Gen/App.hs')
| -rw-r--r-- | compiler/GHC/Tc/Gen/App.hs | 28 |
1 files changed, 12 insertions, 16 deletions
diff --git a/compiler/GHC/Tc/Gen/App.hs b/compiler/GHC/Tc/Gen/App.hs index 06158cace3..c8c1730b35 100644 --- a/compiler/GHC/Tc/Gen/App.hs +++ b/compiler/GHC/Tc/Gen/App.hs @@ -543,25 +543,16 @@ tcInstFun do_ql inst_final (rn_fun, fun_ctxt) fun_sigma rn_args HsUnboundVar {} -> True _ -> False - inst_all, inst_inferred, inst_none :: ForAllTyFlag -> Bool - inst_all (Invisible {}) = True - inst_all Required = False - - inst_inferred (Invisible InferredSpec) = True - inst_inferred (Invisible SpecifiedSpec) = False - inst_inferred Required = False - - inst_none _ = False - inst_fun :: [HsExprArg 'TcpRn] -> ForAllTyFlag -> Bool - inst_fun [] | inst_final = inst_all - | otherwise = inst_none - -- Using `inst_none` for `:type` avoids + -- True <=> instantiate a tyvar with this ForAllTyFlag + inst_fun [] | inst_final = isInvisibleForAllTyFlag + | otherwise = const False + -- Using `const False` for `:type` avoids -- `forall {r1} (a :: TYPE r1) {r2} (b :: TYPE r2). a -> b` -- turning into `forall a {r2} (b :: TYPE r2). a -> b`. -- See #21088. - inst_fun (EValArg {} : _) = inst_all - inst_fun _ = inst_inferred + inst_fun (EValArg {} : _) = isInvisibleForAllTyFlag + inst_fun _ = isInferredForAllTyFlag ----------- go, go1 :: Delta @@ -588,7 +579,12 @@ tcInstFun do_ql inst_final (rn_fun, fun_ctxt) fun_sigma rn_args -- c.f. GHC.Tc.Utils.Instantiate.topInstantiate go1 delta acc so_far fun_ty args | (tvs, body1) <- tcSplitSomeForAllTyVars (inst_fun args) fun_ty - , (theta, body2) <- tcSplitPhiTy body1 + , (theta, body2) <- if inst_fun args Inferred + then tcSplitPhiTy body1 + else ([], body1) + -- inst_fun args Inferred: dictionary parameters are like Inferred foralls + -- E.g. #22908: f :: Foo => blah + -- No foralls! But if inst_final=False, don't instantiate , not (null tvs && null theta) = do { (inst_tvs, wrap, fun_rho) <- addHeadCtxt fun_ctxt $ instantiateSigma fun_orig tvs theta body2 |