From e40b11a91cb345db1324c3cb8f75b01e28056693 Mon Sep 17 00:00:00 2001 From: Jonathan Wakely Date: Tue, 16 Jun 2020 22:34:55 +0100 Subject: [PATCH] libstdc++: Strip cv-qualifiers in std::atomic (PR 95282) This improves the previous fix for PR 95282, and extends it to also apply to the exchange function (which has a similar problem and would become ill-formed with my proposed fix for PR 95378). PR libstdc++/95282 * include/bits/atomic_base.h (__atomic_impl::load): Use the _Val alias instead of deducing _Tp as an unqualified type. (__atomic_impl::exchange): Use the _Val alias to remove volatile from the reinterpret_cast result type. --- libstdc++-v3/include/bits/atomic_base.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/libstdc++-v3/include/bits/atomic_base.h b/libstdc++-v3/include/bits/atomic_base.h index ebcfeb4d51a..015acef83c4 100644 --- a/libstdc++-v3/include/bits/atomic_base.h +++ b/libstdc++-v3/include/bits/atomic_base.h @@ -870,21 +870,21 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION { __atomic_store(__ptr, std::__addressof(__t), int(__m)); } template - _GLIBCXX_ALWAYS_INLINE _Tp - load(const volatile _Tp* __ptr, memory_order __m) noexcept + _GLIBCXX_ALWAYS_INLINE _Val<_Tp> + load(const _Tp* __ptr, memory_order __m) noexcept { alignas(_Tp) unsigned char __buf[sizeof(_Tp)]; - _Tp* __dest = reinterpret_cast<_Tp*>(__buf); + auto* __dest = reinterpret_cast<_Val<_Tp>*>(__buf); __atomic_load(__ptr, __dest, int(__m)); return *__dest; } template - _GLIBCXX_ALWAYS_INLINE _Tp + _GLIBCXX_ALWAYS_INLINE _Val<_Tp> exchange(_Tp* __ptr, _Val<_Tp> __desired, memory_order __m) noexcept { alignas(_Tp) unsigned char __buf[sizeof(_Tp)]; - _Tp* __dest = reinterpret_cast<_Tp*>(__buf); + auto* __dest = reinterpret_cast<_Val<_Tp>*>(__buf); __atomic_exchange(__ptr, std::__addressof(__desired), __dest, int(__m)); return *__dest; } -- 2.30.2