From 9e2eef4fa078757fec394d1785ed8120fd0cf101 Mon Sep 17 00:00:00 2001
From: Bruce Mitchener <bruce.mitchener@gmail.com>
Date: Fri, 5 Jul 2013 15:50:54 +0700
Subject: [PATCH] Don't define _gnu_source if already defined.

When using the build method of including the MPS directly into
one's own sources, that build system may already define _GNU_SOURCE
causing a warning here about re-defining it.

Copied from Perforce
 Change: 182941
 ServerID: perforce.ravenbrook.com
---
 mps/code/config.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/mps/code/config.h b/mps/code/config.h
index 370542b5a2e..49d14e42e22 100644
--- a/mps/code/config.h
+++ b/mps/code/config.h
@@ -356,7 +356,10 @@
 #if defined(MPS_OS_LI)
 
 #define _XOPEN_SOURCE 500
+
+#ifndef _GNU_SOURCE
 #define _GNU_SOURCE
+#endif
 
 #endif