From 9b1fbc3f8f7eba432dc20f52f7ba8948a1510a2e Mon Sep 17 00:00:00 2001
From: Neil Brown <neil@twistedsquare.com>
Date: Wed, 12 Sep 2007 08:45:23 +0000
Subject: [PATCH] Added a helper function for creating passes that check the
 validity of the AST

---
 common/Pass.hs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/common/Pass.hs b/common/Pass.hs
index 64aa5f2..43d7331 100644
--- a/common/Pass.hs
+++ b/common/Pass.hs
@@ -30,6 +30,7 @@ import CompState
 import Errors
 import Metadata
 import PrettyShow
+import TreeUtil
 
 -- | The monad in which AST-mangling passes operate.
 type PassM = ErrorT String (StateT CompState IO)
@@ -105,3 +106,8 @@ makeGeneric top
         `extM` (return :: String -> PassM String)
         `extM` (return :: Meta -> PassM Meta)
 
+excludeConstr :: Data a => [Constr] -> a -> PassM a
+excludeConstr cons x 
+  = if null items then return x else dieInternal $ "Excluded item still remains in source tree: " ++ (show $ head items) ++ " tree is: " ++ pshow x
+      where
+        items = checkTreeForConstr cons x