X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2FcodeGen%2FClosureInfo.lhs;h=27aed3a70e8163bf084e015a042e9e716f681c19;hb=3d8dbba7d24c9139b800f4ccf31c50b11596fc2e;hp=8f62bc7e0e2a3b99db27f9e1a6c4014dc8ba41b8;hpb=41c97fdcffd38949f89af8094a9f60203b189531;p=ghc-hetmet.git

diff --git a/compiler/codeGen/ClosureInfo.lhs b/compiler/codeGen/ClosureInfo.lhs
index 8f62bc7..27aed3a 100644
--- a/compiler/codeGen/ClosureInfo.lhs
+++ b/compiler/codeGen/ClosureInfo.lhs
@@ -257,12 +257,12 @@ mkLFThunk thunk_ty top fvs upd_flag
 	    (might_be_a_function thunk_ty)
 
 might_be_a_function :: Type -> Bool
+-- Return False only if we are *sure* it's a data type
+-- Look through newtypes etc as much as poss
 might_be_a_function ty
-  | Just (tc,_) <- splitTyConApp_maybe (repType ty), 
-    not (isFunTyCon tc)  && not (isAbstractTyCon tc) = False
-	-- don't forget to check for abstract types, which might
-	-- be functions too.
-  | otherwise = True
+  = case splitTyConApp_maybe (repType ty) of
+	Just (tc, _) -> not (isDataTyCon tc)
+	Nothing	     -> True
 \end{code}
 
 @mkConLFInfo@ is similar, for constructors.
@@ -594,7 +594,13 @@ getCallMethod this_pkg name (LFThunk _ _ updatable std_form_info is_fun) n_args
 	 if we enter the same thunk multiple times, so the optimisation
 	 of jumping directly to the entry code is still valid.  --SDM
 	-}
-  = ASSERT2( n_args == 0, ppr name ) EnterIt
+  = EnterIt
+    -- We used to have ASSERT( n_args == 0 ), but actually it is
+    -- possible for the optimiser to generate
+    --   let bot :: Int = error Int "urk"
+    --   in (bot `cast` unsafeCoerce Int (Int -> Int)) 3
+    -- This happens as a result of the case-of-error transformation
+    -- So the right thing to do is just to enter the thing
 
   | otherwise	-- Jump direct to code for single-entry thunks
   = ASSERT( n_args == 0 )