X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Fiface%2FBuildTyCl.lhs;h=de1c1915a67e37c4fd9ff0845ffc5c11dfc30393;hb=a19691137898050be08580092ed6f22213f66c27;hp=54adfdf84c761649f39b7cb3ef799622f4c65fa1;hpb=09d2b3b2e1f9d0a4c4b938dc6ff6a0b068138445;p=ghc-hetmet.git

diff --git a/compiler/iface/BuildTyCl.lhs b/compiler/iface/BuildTyCl.lhs
index 54adfdf..de1c191 100644
--- a/compiler/iface/BuildTyCl.lhs
+++ b/compiler/iface/BuildTyCl.lhs
@@ -121,7 +121,12 @@ mkDataTyConRhs cons
   = DataTyCon {
         data_cons = cons,
         is_enum = -- We define datatypes with no constructors to not be
-                  -- enumerations; this fixes trac #2578
+                  -- enumerations; this fixes trac #2578,  Otherwise we
+                  -- end up generating an empty table for
+                  --   <mod>_<type>_closure_tbl
+                  -- which is used by tagToEnum# to map Int# to constructors
+                  -- in an enumeration. The empty table apparently upset
+                  -- the linker.
                   not (null cons) &&
                   all isNullarySrcDataCon cons
     }