From 984171edf6b077015cc4229693460b49198a32da Mon Sep 17 00:00:00 2001
From: Jorge Aparicio <jorge@japaric.io>
Date: Mon, 5 Jun 2017 20:57:17 -0500
Subject: [PATCH] fix unused macro error

---
 src/lib.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/lib.rs b/src/lib.rs
index 81078d4e5f..e325d27f08 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -445,6 +445,7 @@ pub use cortex_m::asm::{bkpt, wfi};
 pub use cortex_m::peripheral::NVIC as _NVIC;
 
 /// Compiler barrier
+#[cfg(not(thumbv6m))]
 macro_rules! barrier {
     () => {
         asm!(""