From 5735cb8ec021484a549c5da48b5c6f877ad18bf8 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Mon, 8 Jun 2020 12:04:20 +0200
Subject: [PATCH] Do a volatile read in stack_overflow test to avoid tail
 recursion

This prevents the compiler from transforming the tail recursive function into a loop, which does not lead to a stack overflow. It also avoids the LLVM bug where functions with side-effect-free endless loops are removed. Thus, the test now also works in `--release` mode.
---
 tests/stack_overflow.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tests/stack_overflow.rs b/tests/stack_overflow.rs
index 71ad12d6a..845644b45 100644
--- a/tests/stack_overflow.rs
+++ b/tests/stack_overflow.rs
@@ -23,6 +23,7 @@ pub extern "C" fn _start() -> ! {
 #[allow(unconditional_recursion)]
 fn stack_overflow() {
     stack_overflow(); // for each recursion, the return address is pushed
+    volatile::Volatile::new(0).read(); // prevent tail recursion optimizations
 }
 
 lazy_static! {