We declare atomic_init() but then never define it, I assume that's
just an accident.
Although the standard says this function is non-atomic, the simplest
fix at this stage is just to do an atomic store (when we get to stage
1 again I'd like to make the function a friend of std::__atomic_base<>
so it can set the private member variable directly as a simple
non-atomic assignment).
Tested x86_64-linux, *not* committed to trunk.
commit 061dd1a073ef4646727a3f29dfa3169a760757b3
Author: Jonathan Wakely <jwak...@redhat.com>
Date: Sun Jan 18 17:40:17 2015 +0000
PR libstdc++/64658
* include/std/atomic (atomic_init): Define.
* testsuite/29_atomics/atomic/64658.cc: New.
diff --git a/libstdc++-v3/include/std/atomic b/libstdc++-v3/include/std/atomic
index 43cf4f3..1a17427 100644
--- a/libstdc++-v3/include/std/atomic
+++ b/libstdc++-v3/include/std/atomic
@@ -921,11 +921,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _ITp>
inline void
- atomic_init(atomic<_ITp>* __a, _ITp __i) noexcept;
+ atomic_init(atomic<_ITp>* __a, _ITp __i) noexcept
+ { __a->store(__i, memory_order_relaxed); }
template<typename _ITp>
inline void
- atomic_init(volatile atomic<_ITp>* __a, _ITp __i) noexcept;
+ atomic_init(volatile atomic<_ITp>* __a, _ITp __i) noexcept
+ { __a->store(__i, memory_order_relaxed); }
template<typename _ITp>
inline void
diff --git a/libstdc++-v3/testsuite/29_atomics/atomic/64658.cc b/libstdc++-v3/testsuite/29_atomics/atomic/64658.cc
new file mode 100644
index 0000000..64739e0
--- /dev/null
+++ b/libstdc++-v3/testsuite/29_atomics/atomic/64658.cc
@@ -0,0 +1,29 @@
+// Copyright (C) 2015 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-require-atomic-builtins "" }
+// { dg-options "-std=gnu++11" }
+// { dg-do link }
+
+#include <atomic>
+
+int
+main()
+{
+ std::atomic<int> i;
+ atomic_init(&i, 0);
+}
