Merge pull request #3079 from vespa-engine/balder/show-behavioral-change-between-gcc-6-and-7

Document behavioral change between gcc 6 and 7.

1 files changed, 5 insertions, 0 deletions

diff --git a/vespamalloc/src/tests/test1/testatomic.cpp b/vespamalloc/src/tests/test1/testatomic.cpp
index 686536ae252..448b0776f1a 100644
--- a/vespamalloc/src/tests/test1/testatomic.cpp
+++ b/vespamalloc/src/tests/test1/testatomic.cpp
@@ -112,7 +112,12 @@ int Test::Main()
     {
         std::atomic<vespamalloc::TaggedPtr> taggedPtr;
         ASSERT_EQUAL(16u, sizeof(vespamalloc::TaggedPtr));
+#if __GNUC__ < 7
+        // See https://gcc.gnu.org/ml/gcc-patches/2017-01/msg02344.html for background
         ASSERT_TRUE(taggedPtr.is_lock_free());
+#else
+        ASSERT_FALSE(taggedPtr.is_lock_free());
+#endif
     }
 
     testSwap<uint32_t>(6);