Turn "NOTE: Simplifier still going..." message into a WARN()

[ghc-hetmet.git] / compiler / simplCore / SimplUtils.lhs

diff --git a/compiler/simplCore/SimplUtils.lhs b/compiler/simplCore/SimplUtils.lhs
index 45ef88a..84506d8 100644 (file)
--- a/compiler/simplCore/SimplUtils.lhs
+++ b/compiler/simplCore/SimplUtils.lhs
@@ -1425,6 +1425,11 @@ prepareDefault _ _ case_bndr (Just (tycon, inst_tys)) imposs_cons (Just deflt_rh
 
        _ -> return [(DEFAULT, [], deflt_rhs)]
 
+  | debugIsOn, isAlgTyCon tycon, [] <- tyConDataCons tycon
+  = pprTrace "prepareDefault" (ppr case_bndr <+> ppr tycon)
+       -- This can legitimately happen for type families
+        $ return [(DEFAULT, [], deflt_rhs)]
+
 --------- Catch-all cases -----------
 prepareDefault _dflags _env _case_bndr _bndr_ty _imposs_cons (Just deflt_rhs)
   = return [(DEFAULT, [], deflt_rhs)]