From 524c609b6d8d220b03640dc71a209530bf2ed280 Mon Sep 17 00:00:00 2001
From: "simonpj@microsoft.com" <unknown>
Date: Thu, 8 Oct 2009 16:23:29 +0000
Subject: [PATCH] Make tyConSingleDataCon_maybe more forgiving

This function was barfing on a type family tycon; which in turn
crashed the compiler (when -ticky is in use) because of the use in
CmmTicky.hs.  There's no need for it to reject such tycons, so I just
made it return Nothing rather than falling over.
---
 compiler/types/TyCon.lhs |   11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/compiler/types/TyCon.lhs b/compiler/types/TyCon.lhs
index a7b0594..bb21536 100644
--- a/compiler/types/TyCon.lhs
+++ b/compiler/types/TyCon.lhs
@@ -1097,13 +1097,10 @@ synTyConResKind tycon  = pprPanic "synTyConResKind" (ppr tycon)
 -- has more than one constructor, or represents a primitive or function type constructor then
 -- @Nothing@ is returned. In any other case, the function panics
 tyConSingleDataCon_maybe :: TyCon -> Maybe DataCon
-tyConSingleDataCon_maybe (AlgTyCon {algTcRhs = DataTyCon {data_cons = [c] }}) = Just c
-tyConSingleDataCon_maybe (AlgTyCon {algTcRhs = NewTyCon { data_con = c }})    = Just c
-tyConSingleDataCon_maybe (AlgTyCon {})	         = Nothing
-tyConSingleDataCon_maybe (TupleTyCon {dataCon = con}) = Just con
-tyConSingleDataCon_maybe (PrimTyCon {})               = Nothing
-tyConSingleDataCon_maybe (FunTyCon {})                = Nothing  -- case at funty
-tyConSingleDataCon_maybe tc = pprPanic "tyConSingleDataCon_maybe: unexpected tycon " $ ppr tc
+tyConSingleDataCon_maybe (TupleTyCon {dataCon = c}) 			       = Just c
+tyConSingleDataCon_maybe (AlgTyCon {algTcRhs = DataTyCon { data_cons = [c] }}) = Just c
+tyConSingleDataCon_maybe (AlgTyCon {algTcRhs = NewTyCon { data_con = c }})     = Just c
+tyConSingleDataCon_maybe _                           			       = Nothing
 \end{code}
 
 \begin{code}
-- 
1.7.10.4