From 6993bb4eb6c358c390f674a10f8a8ca69d9ee0fe Mon Sep 17 00:00:00 2001
From: James Almer <jamrial@gmail.com>
Date: Tue, 27 Dec 2016 21:54:55 -0300
Subject: [PATCH] configure: make the check for stdatomic.h stricter

Old ICC verions don't advertise having a full C11 implementation but
may nonetheless include a feature-incomplete stdatomic.h header.

Fixes ticket #6049

Signed-off-by: James Almer <jamrial@gmail.com>
---
 configure | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/configure b/configure
index d723b8e2a6a..56a0b657a9e 100755
--- a/configure
+++ b/configure
@@ -5623,7 +5623,7 @@ check_header asm/types.h
 # it seems there are versions of clang in some distros that try to use the
 # gcc headers, which explodes for stdatomic
 # so we also check that atomics actually work here
-check_builtin stdatomic_h stdatomic.h "atomic_int foo; atomic_store(&foo, 0)"
+check_builtin stdatomic_h stdatomic.h "atomic_int foo, bar = ATOMIC_VAR_INIT(-1); atomic_store(&foo, 0)"
 
 check_lib2 "windows.h shellapi.h" CommandLineToArgvW -lshell32
 check_lib2 "windows.h wincrypt.h" CryptGenRandom -ladvapi32
-- 
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