X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2FhsSyn%2FHsUtils.lhs;h=b0978ec6494b5f296fb2b6d07a0af9a6782ec735;hp=5d7132ec74399dccfd54752de134ba4f18b925b6;hb=85eebc52605f5fd4d3bbdb1a37f7134948f740ca;hpb=30098da67fd3ce50ef5a110f57c1780002f83615

diff --git a/compiler/hsSyn/HsUtils.lhs b/compiler/hsSyn/HsUtils.lhs
index 5d7132e..b0978ec 100644
--- a/compiler/hsSyn/HsUtils.lhs
+++ b/compiler/hsSyn/HsUtils.lhs
@@ -428,7 +428,10 @@ collect_pat other	        acc = acc 	-- Literals, vars, wildcard
 
 getMainDeclBinder :: HsDecl name -> Maybe name
 getMainDeclBinder (TyClD d) = Just (tcdName d)
-getMainDeclBinder (ValD d) = Just ((unLoc . head) (collectAcc d []))
+getMainDeclBinder (ValD d)
+   = case collectAcc d [] of
+        []       -> Nothing   -- see rn003
+        (name:_) -> Just (unLoc name)
 getMainDeclBinder (SigD d) = sigNameNoLoc d
 getMainDeclBinder (ForD (ForeignImport name _ _)) = Just (unLoc name)
 getMainDeclBinder (ForD (ForeignExport name _ _)) = Just (unLoc name)