From 3071050a396a15a58234303184eb1aeb6d785c64 Mon Sep 17 00:00:00 2001
From: Chris Johns <chrisj@rtems.org>
Date: Mon, 5 Nov 2012 11:52:16 +1100
Subject: [PATCH] Allow defines with the macro is empty.

---
 sb/config.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sb/config.py b/sb/config.py
index 88a8148..a9724dc 100644
--- a/sb/config.py
+++ b/sb/config.py
@@ -403,7 +403,8 @@ class file:
             self._warning('invalid macro definition')
         else:
             d = self._label(ls[1])
-            if d not in self.defines:
+            if (d not in self.defines) or \
+                    (d in self.defines and len(self.defines[d]) == 0):
                 if len(ls) == 2:
                     self.defines[d] = '1'
                 else: