From 90523ae975dc1f796171711e99b207efa127435d Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <tridge@samba.org>
Date: Wed, 9 Jan 2013 20:41:37 +1100
Subject: [PATCH] AP_HAL: added WARN_IF_UNUSED macro

useful for key functions
---
 libraries/AP_HAL/AP_HAL.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/libraries/AP_HAL/AP_HAL.h b/libraries/AP_HAL/AP_HAL.h
index 023cf19421..71ab8cf043 100644
--- a/libraries/AP_HAL/AP_HAL.h
+++ b/libraries/AP_HAL/AP_HAL.h
@@ -8,6 +8,12 @@
 #include "AP_HAL_Namespace.h"
 #include "AP_HAL_Boards.h"
 
+#ifdef __GNUC__
+ #define WARN_IF_UNUSED __attribute__ ((warn_unused_result))
+#else
+ #define WARN_IF_UNUSED
+#endif
+
 /* HAL Module Classes (all pure virtual) */
 #include "UARTDriver.h"
 #include "I2CDriver.h"