diff options
| -rw-r--r-- | compiler/typecheck/TcTyClsDecls.hs | 10 | ||||
| -rw-r--r-- | testsuite/tests/typecheck/should_fail/all.T | 2 |
2 files changed, 9 insertions, 3 deletions
diff --git a/compiler/typecheck/TcTyClsDecls.hs b/compiler/typecheck/TcTyClsDecls.hs index 7fec6f4dd3..64798c94d7 100644 --- a/compiler/typecheck/TcTyClsDecls.hs +++ b/compiler/typecheck/TcTyClsDecls.hs @@ -3412,8 +3412,14 @@ checkValidTyCon tc | Just fam_flav <- famTyConFlav_maybe tc -> case fam_flav of { ClosedSynFamilyTyCon (Just ax) - -> tcAddClosedTypeFamilyDeclCtxt tc $ - checkValidCoAxiom ax + -> tcAddClosedTypeFamilyDeclCtxt tc $ do + -- Ensure that the TyCon in the equation matches + -- the tycon of the class head. See #17633. + checkTc (co_ax_tc tc == tc) + text "The type constructor" <+> ppr (co_ax_tc tc) <+> + text "in the LHS of the equation must match the family" <+> + text "name" <+> ppr tc <> text "." + checkValidCoAxiom tc ax ; ClosedSynFamilyTyCon Nothing -> return () ; AbstractClosedSynFamilyTyCon -> do { hsBoot <- tcIsHsBootOrSig diff --git a/testsuite/tests/typecheck/should_fail/all.T b/testsuite/tests/typecheck/should_fail/all.T index 7c3763a364..0ee1d6c386 100644 --- a/testsuite/tests/typecheck/should_fail/all.T +++ b/testsuite/tests/typecheck/should_fail/all.T @@ -549,4 +549,4 @@ test('T17213', [extra_files(['T17213a.hs'])], multimod_compile_fail, ['T17213', test('T17355', normal, compile_fail, ['']) test('T17360', normal, compile_fail, ['']) test('T17563', normal, compile_fail, ['']) -test('T17633', expect_broken(17633), compile_fail, ['']) +test('T17633', normal, compile_fail, ['']) |