From 50ce52016139a4346a94df71249c14c5d286e000 Mon Sep 17 00:00:00 2001
From: Abseil Team <absl-team@google.com>
Date: Fri, 8 Jan 2021 15:00:47 -0500
Subject: [PATCH] Googletest export

Launder buffer before reference

In GCC, directly casting the Buffer reference to another type results in
strict-aliasing violation errors. This launders the reference using an
intermediate pointer prior to creating the new reference.

PiperOrigin-RevId: 350809323
---
 googletest/include/gtest/gtest-matchers.h | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/googletest/include/gtest/gtest-matchers.h b/googletest/include/gtest/gtest-matchers.h
index 6b1bb6af..1bb3140d 100644
--- a/googletest/include/gtest/gtest-matchers.h
+++ b/googletest/include/gtest/gtest-matchers.h
@@ -421,7 +421,11 @@ class MatcherBase : private MatcherDescriberInterface {
   template <typename M, bool = IsInlined<M>()>
   struct ValuePolicy {
     static const M& Get(const MatcherBase& m) {
-      return reinterpret_cast<const M&>(m.buffer_);
+      // When inlined along with Init, need to be explicit to avoid violating
+      // strict aliasing rules.
+      const M *ptr = static_cast<const M*>(
+          static_cast<const void*>(&m.buffer_));
+      return *ptr;
     }
     static void Init(MatcherBase& m, M impl) {
       ::new (static_cast<void*>(&m.buffer_)) M(impl);