From 61ac138b5cc9c6e6d7a4ac33135c6086d2d4d644 Mon Sep 17 00:00:00 2001
From: Mara Bos <m-ou.se@m-ou.se>
Date: Sat, 5 Sep 2020 11:33:01 +0200
Subject: [PATCH] Disable atomics on avr target.

`max_atomic_width` was missing in the spec, which means it fell back to
the pointer width of 16 bits.
---
 compiler/rustc_target/src/spec/avr_gnu_base.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/compiler/rustc_target/src/spec/avr_gnu_base.rs b/compiler/rustc_target/src/spec/avr_gnu_base.rs
index ff559c2bfd684..527a322d56a4f 100644
--- a/compiler/rustc_target/src/spec/avr_gnu_base.rs
+++ b/compiler/rustc_target/src/spec/avr_gnu_base.rs
@@ -45,6 +45,8 @@ pub fn target(target_cpu: String) -> TargetResult {
             late_link_args: vec![(LinkerFlavor::Gcc, vec!["-lgcc".to_owned()])]
                 .into_iter()
                 .collect(),
+            max_atomic_width: Some(0),
+            atomic_cas: false,
             ..TargetOptions::default()
         },
     })