From: Jonathan Wakely <jwakely@redhat.com>
To: Thomas Rodgers <rodgert@appliantology.com>
Cc: gcc-patches@gcc.gnu.org, libstdc++@gcc.gnu.org, trodgers@redhat.com
Subject: Re: [PATCH] Add feature test macro for atomic<T>::wait
Date: Tue, 1 Dec 2020 14:52:28 +0000 [thread overview]
Message-ID: <20201201145228.GJ2309743@redhat.com> (raw)
In-Reply-To: <20201130181740.1112277-1-rodgert@appliantology.com>
On 30/11/20 10:17 -0800, Thomas Rodgers wrote:
>From: Thomas Rodgers <trodgers@redhat.com>
>
>Adds __cpp_lib_atomic_wait feature test macro which was overlooked in
>the initial commit of this feature. Replaces uses of
>_GLIBCXX_HAVE_ATOMIC_WAIT.
>
>libstdc++-v3/ChangeLog:
>
> * include/bits/atomic_base.h: Replace usage of
> _GLIBCXX_HAVE_ATOMIC_WAIT with __cpp_lib_atomic_wait.
> * include/bits/atomic_timed_wait.h: Likewise.
> * include/bits/atomic_wait.h: Define __cpp_lib_atomic_wait
> feature test macro.
> * include/bits/semaphore_base: Replace usage of
> _GLIBCXX_HAVE_ATOMIC_WAIT with __cpp_lib_atomic_wait.
> * include/std/atomic: Likewise.
> * include/std/latch: Likewise.
> * include/std/semaphore: Likewise.
> * include/std/version: Define __cpp_lib_atomic wait
> feature test macro and replace usage of
> _GLIBCXX_HAVE_ATOMIC_WAIT.
> * testsuite/29_atomics/atomic/wait_notify/1.cc: New test.
> * testsuite/29_atomics/atomic/wait_notify/2.cc: Likewise.
>
>---
> libstdc++-v3/include/bits/atomic_base.h | 36 +++++++++----------
> libstdc++-v3/include/bits/atomic_timed_wait.h | 5 +--
> libstdc++-v3/include/bits/atomic_wait.h | 3 +-
> libstdc++-v3/include/bits/semaphore_base.h | 4 +--
> libstdc++-v3/include/std/atomic | 16 ++++-----
> libstdc++-v3/include/std/latch | 4 +--
> libstdc++-v3/include/std/semaphore | 4 +--
> libstdc++-v3/include/std/version | 7 ++--
> .../29_atomics/atomic/wait_notify/1.cc | 28 +++++++++++++++
> .../29_atomics/atomic/wait_notify/2.cc | 29 +++++++++++++++
> 10 files changed, 98 insertions(+), 38 deletions(-)
> create mode 100644 libstdc++-v3/testsuite/29_atomics/atomic/wait_notify/1.cc
> create mode 100644 libstdc++-v3/testsuite/29_atomics/atomic/wait_notify/2.cc
>
>diff --git a/libstdc++-v3/include/bits/atomic_base.h b/libstdc++-v3/include/bits/atomic_base.h
>index d0d962d3047..ad4e24b4d20 100644
>--- a/libstdc++-v3/include/bits/atomic_base.h
>+++ b/libstdc++-v3/include/bits/atomic_base.h
>@@ -230,7 +230,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> return __v == __GCC_ATOMIC_TEST_AND_SET_TRUEVAL;
> }
>
>-#ifdef _GLIBCXX_HAVE_ATOMIC_WAIT
>+#ifdef __cpp_lib_atomic_wait
I've not always been consistent about using #if or #ifdef for
__cpp_lib macros, but let's not make that worse in a single patch. I
think we should just use #if for __cpp_lib macros. That affects
several places in the patch.
> _GLIBCXX_ALWAYS_INLINE void
> wait(bool __old,
> memory_order __m = memory_order_seq_cst) const noexcept
>@@ -253,7 +253,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> { std::__atomic_notify(&_M_i, true); }
>
> // TODO add const volatile overload
>-#endif // HAVE_ATOMIC_WAIT
>+#endif // __cpp_lib_atomic_wait
> #endif // C++20
>
> _GLIBCXX_ALWAYS_INLINE void
>@@ -604,7 +604,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> __cmpexch_failure_order(__m));
> }
>
>-#if __cplusplus > 201703L && defined _GLIBCXX_HAVE_ATOMIC_WAIT
>+#if __cpp_lib_atomic_wait
> _GLIBCXX_ALWAYS_INLINE void
> wait(__int_type __old,
> memory_order __m = memory_order_seq_cst) const noexcept
>@@ -627,7 +627,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> { std::__atomic_notify(&_M_i, true); }
>
> // TODO add const volatile overload
>-#endif // C++20 && HAVE_ATOMIC_WAIT
>+#endif // __cpp_lib_atomic_wait
>
> _GLIBCXX_ALWAYS_INLINE __int_type
> fetch_add(__int_type __i,
>@@ -898,7 +898,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> int(__m1), int(__m2));
> }
>
>-#if __cplusplus > 201703L && defined _GLIBCXX_HAVE_ATOMIC_WAIT
>+#if __cpp_lib_atomic_wait
> _GLIBCXX_ALWAYS_INLINE void
> wait(__pointer_type __old,
> memory_order __m = memory_order_seq_cst) noexcept
>@@ -921,7 +921,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> { std::__atomic_notify(&_M_p, true); }
>
> // TODO add const volatile overload
>-#endif // C++20 && HAVE_ATOMIC_WAIT
>+#endif // __cpp_lib_atomic_wait
>
> _GLIBCXX_ALWAYS_INLINE __pointer_type
> fetch_add(ptrdiff_t __d,
>@@ -1011,7 +1011,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> int(__success), int(__failure));
> }
>
>-#if __cplusplus > 201703L && defined _GLIBCXX_HAVE_ATOMIC_WAIT
>+#if __cpp_lib_atomic_wait
> template<typename _Tp>
> _GLIBCXX_ALWAYS_INLINE void
> wait(const _Tp* __ptr, _Val<_Tp> __old,
>@@ -1036,7 +1036,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> { std::__atomic_notify(__ptr, true); }
>
> // TODO add const volatile overload
>-#endif // C++20 && HAVE_ATOMIC_WAIT
>+#endif // __cpp_lib_atomic_wait
>
> template<typename _Tp>
> _GLIBCXX_ALWAYS_INLINE _Tp
>@@ -1291,7 +1291,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> __cmpexch_failure_order(__order));
> }
>
>-#ifdef _GLIBCXX_HAVE_ATOMIC_WAIT
>+#ifdef __cpp_lib_atomic_wait
> _GLIBCXX_ALWAYS_INLINE void
> wait(_Fp __old, memory_order __m = memory_order_seq_cst) const noexcept
> { __atomic_impl::wait(&_M_fp, __old, __m); }
>@@ -1309,7 +1309,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> { __atomic_impl::notify_all(&_M_fp); }
>
> // TODO add const volatile overload
>-#endif // HAVE_ATOMIC_WAIT
>+#endif // __cpp_lib_atomic_wait
>
> value_type
> fetch_add(value_type __i,
>@@ -1448,7 +1448,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> __cmpexch_failure_order(__order));
> }
>
>-#ifdef _GLIBCXX_HAVE_ATOMIC_WAIT
>+#ifdef __cpp_lib_atomic_wait
> _GLIBCXX_ALWAYS_INLINE void
> wait(_Tp __old, memory_order __m = memory_order_seq_cst) const noexcept
> { __atomic_impl::wait(_M_ptr, __old, __m); }
>@@ -1466,7 +1466,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> { __atomic_impl::notify_all(_M_ptr); }
>
> // TODO add const volatile overload
>-#endif // HAVE_ATOMIC_WAIT
>+#endif // __cpp_lib_atomic_wait
>
> private:
> _Tp* _M_ptr;
>@@ -1563,7 +1563,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> __cmpexch_failure_order(__order));
> }
>
>-#ifdef _GLIBCXX_HAVE_ATOMIC_WAIT
>+#ifdef __cpp_lib_atomic_wait
> _GLIBCXX_ALWAYS_INLINE void
> wait(_Tp __old, memory_order __m = memory_order_seq_cst) const noexcept
> { __atomic_impl::wait(_M_ptr, __old, __m); }
>@@ -1581,7 +1581,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> { __atomic_impl::notify_all(_M_ptr); }
>
> // TODO add const volatile overload
>-#endif // HAVE_ATOMIC_WAIT
>+#endif // __cpp_lib_atomic_wait
>
> value_type
> fetch_add(value_type __i,
>@@ -1738,7 +1738,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> __cmpexch_failure_order(__order));
> }
>
>-#ifdef _GLIBCXX_HAVE_ATOMIC_WAIT
>+#ifdef __cpp_lib_atomic_wait
> _GLIBCXX_ALWAYS_INLINE void
> wait(_Fp __old, memory_order __m = memory_order_seq_cst) const noexcept
> { __atomic_impl::wait(_M_ptr, __old, __m); }
>@@ -1756,7 +1756,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> { __atomic_impl::notify_all(_M_ptr); }
>
> // TODO add const volatile overload
>-#endif // HAVE_ATOMIC_WAIT
>+#endif // __cpp_lib_atomic_wait
>
> value_type
> fetch_add(value_type __i,
>@@ -1867,7 +1867,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> __cmpexch_failure_order(__order));
> }
>
>-#ifdef _GLIBCXX_HAVE_ATOMIC_WAIT
>+#ifdef __cpp_lib_atomic_wait
> _GLIBCXX_ALWAYS_INLINE void
> wait(_Tp __old, memory_order __m = memory_order_seq_cst) const noexcept
> { __atomic_impl::wait(_M_ptr, __old, __m); }
>@@ -1885,7 +1885,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> { __atomic_impl::notify_all(_M_ptr); }
>
> // TODO add const volatile overload
>-#endif // HAVE_ATOMIC_WAIT
>+#endif // __cpp_lib_atomic_wait
>
> _GLIBCXX_ALWAYS_INLINE value_type
> fetch_add(difference_type __d,
>diff --git a/libstdc++-v3/include/bits/atomic_timed_wait.h b/libstdc++-v3/include/bits/atomic_timed_wait.h
>index f3a07a36722..6dd1a145e69 100644
>--- a/libstdc++-v3/include/bits/atomic_timed_wait.h
>+++ b/libstdc++-v3/include/bits/atomic_timed_wait.h
>@@ -33,7 +33,8 @@
> #pragma GCC system_header
>
> #include <bits/atomic_wait.h>
>-#ifdef _GLIBCXX_HAVE_ATOMIC_WAIT
>+
>+#ifdef __cpp_lib_atomic_wait
> #include <bits/functional_hash.h>
>
> #include <chrono>
>@@ -292,5 +293,5 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> }
> _GLIBCXX_END_NAMESPACE_VERSION
> } // namespace std
>-#endif // HAVE_ATOMIC_WAIT
>+#endif // __cpp_lib_atomic_wait
> #endif // _GLIBCXX_ATOMIC_TIMED_WAIT_H
>diff --git a/libstdc++-v3/include/bits/atomic_wait.h b/libstdc++-v3/include/bits/atomic_wait.h
>index a59ed8cb418..5efd96d22a1 100644
>--- a/libstdc++-v3/include/bits/atomic_wait.h
>+++ b/libstdc++-v3/include/bits/atomic_wait.h
>@@ -50,8 +50,7 @@
> # include <bits/std_mutex.h> // std::mutex, std::__condvar
> #endif
>
>-// Other headers use this to check for the facilities defined in this header.
>-#define _GLIBCXX_HAVE_ATOMIC_WAIT 1
>+#define __cpp_lib_atomic_wait 201907L
>
> namespace std _GLIBCXX_VISIBILITY(default)
> {
>diff --git a/libstdc++-v3/include/bits/semaphore_base.h b/libstdc++-v3/include/bits/semaphore_base.h
>index f2984236e03..0ed1f5895af 100644
>--- a/libstdc++-v3/include/bits/semaphore_base.h
>+++ b/libstdc++-v3/include/bits/semaphore_base.h
>@@ -33,7 +33,7 @@
> #pragma GCC system_header
>
> #include <bits/atomic_base.h>
>-#ifdef _GLIBCXX_HAVE_ATOMIC_WAIT
>+#ifdef __cpp_lib_atomic_wait
> #include <bits/atomic_timed_wait.h>
>
> #include <ext/numeric_traits.h>
>@@ -297,5 +297,5 @@ template<ptrdiff_t __least_max_value>
> _GLIBCXX_END_NAMESPACE_VERSION
> } // namespace std
>
>-#endif // HAVE_ATOMIC_WAIT
>+#endif // __cpp_lib_atomic_wait
> #endif // _GLIBCXX_SEMAPHORE_BASE_H
>diff --git a/libstdc++-v3/include/std/atomic b/libstdc++-v3/include/std/atomic
>index 664af023d77..4a9b00182a3 100644
>--- a/libstdc++-v3/include/std/atomic
>+++ b/libstdc++-v3/include/std/atomic
>@@ -164,7 +164,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> memory_order __m = memory_order_seq_cst) volatile noexcept
> { return _M_base.compare_exchange_strong(__i1, __i2, __m); }
>
>-#if __cplusplus > 201703L && defined _GLIBCXX_HAVE_ATOMIC_WAIT
>+#if __cpp_lib_atomic_wait
> void
> wait(bool __old, memory_order __m = memory_order_seq_cst) const noexcept
> { _M_base.wait(__old, __m); }
>@@ -178,7 +178,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> void
> notify_all() const noexcept
> { _M_base.notify_all(); }
>-#endif // C++20 && HAVE_ATOMIC_WAIT
>+#endif // __cpp_lib_atomic_wait
> };
>
> #if __cplusplus <= 201703L
>@@ -380,7 +380,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> { return compare_exchange_strong(__e, __i, __m,
> __cmpexch_failure_order(__m)); }
>
>-#if __cplusplus > 201703L && defined _GLIBCXX_HAVE_ATOMIC_WAIT
>+#if __cpp_lib_atomic_wait
> void
> wait(_Tp __old, memory_order __m = memory_order_seq_cst) const noexcept
> {
>@@ -404,7 +404,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> void
> notify_all() const noexcept
> { std::__atomic_notify(&_M_i, true); }
>-#endif // C++20 && HAVE_ATOMIC_WAIT
>+#endif // __cpp_lib_atomic_wait
>
> };
> #undef _GLIBCXX20_INIT
>@@ -644,7 +644,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> __cmpexch_failure_order(__m));
> }
>
>-#if __cplusplus > 201703L && _GLIBCXX_HAVE_ATOMIC_WAIT
>+#if __cpp_lib_atomic_wait
> void
> wait(__pointer_type __old, memory_order __m = memory_order_seq_cst) noexcept
> { _M_b.wait(__old, __m); }
>@@ -658,7 +658,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> void
> notify_all() const noexcept
> { _M_b.notify_all(); }
>-#endif // C++20 && HAVE_ATOMIC_WAIT
>+#endif // __cpp_lib_atomic_wait
> __pointer_type
> fetch_add(ptrdiff_t __d,
> memory_order __m = memory_order_seq_cst) noexcept
>@@ -1412,7 +1412,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> }
>
>
>-#if __cplusplus > 201703L && _GLIBCXX_HAVE_ATOMIC_WAIT
>+#if __cpp_lib_atomic_wait
> template<typename _Tp>
> inline void
> atomic_wait(const atomic<_Tp>* __a,
>@@ -1435,7 +1435,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> inline void
> atomic_notify_all(atomic<_Tp>* __a) noexcept
> { __a->notify_all(); }
>-#endif // C++20 && HAVE_ATOMIC_WAIT
>+#endif // __cpp_lib_atomic_wait
>
> // Function templates for atomic_integral and atomic_pointer operations only.
> // Some operations (and, or, xor) are only available for atomic integrals,
>diff --git a/libstdc++-v3/include/std/latch b/libstdc++-v3/include/std/latch
>index 2684b72288f..3ae77cb1cd2 100644
>--- a/libstdc++-v3/include/std/latch
>+++ b/libstdc++-v3/include/std/latch
>@@ -36,7 +36,7 @@
> #include <bits/atomic_base.h>
> #include <ext/numeric_traits.h>
>
>-#ifdef _GLIBCXX_HAVE_ATOMIC_WAIT
>+#ifdef __cpp_lib_atomic_wait
Just #if not #ifdef
> namespace std _GLIBCXX_VISIBILITY(default)
> {
> _GLIBCXX_BEGIN_NAMESPACE_VERSION
>@@ -89,6 +89,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> };
> _GLIBCXX_END_NAMESPACE_VERSION
> } // namespace
>-#endif // HAVE_ATOMIC_WAIT
>+#endif // __cpp_lib_atomic_wait
> #endif // __cplusplus > 201703L
> #endif // _GLIBCXX_LATCH
>diff --git a/libstdc++-v3/include/std/semaphore b/libstdc++-v3/include/std/semaphore
>index 184c7c2867c..0ecf3bf2fa0 100644
>--- a/libstdc++-v3/include/std/semaphore
>+++ b/libstdc++-v3/include/std/semaphore
>@@ -33,7 +33,7 @@
>
> #if __cplusplus > 201703L
> #include <bits/semaphore_base.h>
>-#ifdef _GLIBCXX_HAVE_ATOMIC_WAIT
>+#ifdef __cpp_lib_atomic_wait
#if
> #include <ext/numeric_traits.h>
>
> namespace std _GLIBCXX_VISIBILITY(default)
>@@ -90,6 +90,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> using binary_semaphore = std::counting_semaphore<1>;
> _GLIBCXX_END_NAMESPACE_VERSION
> } // namespace
>-#endif // HAVE_ATOMIC_WAIT
>+#endif // __cpp_lib_atomic_wait
> #endif // C++20
> #endif // _GLIBCXX_SEMAPHORE
>diff --git a/libstdc++-v3/include/std/version b/libstdc++-v3/include/std/version
>index 0f2da8a5ddd..e5502c9e84b 100644
>--- a/libstdc++-v3/include/std/version
>+++ b/libstdc++-v3/include/std/version
>@@ -197,6 +197,9 @@
> #if _GLIBCXX_HOSTED
> #define __cpp_lib_array_constexpr 201811L
> #define __cpp_lib_assume_aligned 201811L
>+#if defined _GLIBCXX_HAS_GTHREADS || defined _GLIBCXX_HAVE_LINUX_FUTEX
>+#define __cpp_lib_atomic_wait 201907L
A single space after the # please.
>+#endif
> #define __cpp_lib_bind_front 201907L
> // FIXME: #define __cpp_lib_execution 201902L
> #define __cpp_lib_integer_comparison_functions 202002L
>@@ -216,7 +219,7 @@
> #ifdef _GLIBCXX_HAS_GTHREADS
> # define __cpp_lib_jthread 201911L
> #endif
>-#if defined _GLIBCXX_HAS_GTHREADS || defined _GLIBCXX_HAVE_LINUX_FUTEX
>+#if defined __cpp_lib_atomic_wait
Remove the "defined".
> # define __cpp_lib_latch 201907L
> #endif
> #define __cpp_lib_list_remove_return_type 201806L
>@@ -228,7 +231,7 @@
> #if __cpp_lib_concepts
> # define __cpp_lib_ranges 201911L
> #endif
>-#if defined _GLIBCXX_HAS_GTHREADS || defined _GLIBCXX_HAVE_LINUX_FUTEX
>+#if defined __cpp_lib_atomic_wait
Remove the "defined".
> # define __cpp_lib_semaphore 201907L
> #endif
> #define __cpp_lib_shift 201806L
>diff --git a/libstdc++-v3/testsuite/29_atomics/atomic/wait_notify/1.cc b/libstdc++-v3/testsuite/29_atomics/atomic/wait_notify/1.cc
>new file mode 100644
>index 00000000000..5a08d64c1f0
>--- /dev/null
>+++ b/libstdc++-v3/testsuite/29_atomics/atomic/wait_notify/1.cc
>@@ -0,0 +1,28 @@
>+// Copyright (C) 2020 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-options "-std=gnu++2a" }
>+// { dg-do compile { target c++2a } }
This will fail on targets that don't support the feature.
It needs to be:
// { dg-options "-std=gnu++2a" }
// { dg-do compile { target c++2a } }
// { dg-require-effective-target gthreads }
The last line there works since last week when I added "gthreads" as
an effective target keyword, which replaces:
// { dg-require-gthreads "" }
If we wanted to be really correct it would be:
// { dg-require-effective-target gthreads { target { ! futex } } }
Which requires gthreads only for target { ! futex } i.e. if futexes
are supported, then gthreads is not needed (which exactly matches the
code). But it's good enough to just require gthreads, since in
practice the combination of futex && ! gthreads is probably
non-existent. Keeping the directive more readable is more important
than verifying the feature test macro is defined on non-existent
targets.
>+#include <atomic>
>+
>+#ifndef __cpp_lib_atomic_wait
>+# error "Feature-test macro for atomic wait missing in <atomic>"
>+#elif __cpp_lib_atomic_wait != 201907L
>+# error "Feature-test macro for atomic wait has wrong value in <atomic>"
>+#endif
>+
>diff --git a/libstdc++-v3/testsuite/29_atomics/atomic/wait_notify/2.cc b/libstdc++-v3/testsuite/29_atomics/atomic/wait_notify/2.cc
>new file mode 100644
>index 00000000000..5031a369e79
>--- /dev/null
>+++ b/libstdc++-v3/testsuite/29_atomics/atomic/wait_notify/2.cc
>@@ -0,0 +1,29 @@
>+// Copyright (C) 2020 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-options "-std=gnu++2a" }
>+// { dg-do compile { target c++2a } }
This will fail on non-gthreads targets too. As above.
>+#include <version>
>+
>+#ifndef __cpp_lib_atomic_wait
>+# error "Feature-test macro for atomic wait missing in <version>"
>+#elif __cpp_lib_atomic_wait != 201907L
>+# error "Feature-test macro for atomic wait has wrong value in <version>"
>+#endif
OK with those changes, thanks.
next prev parent reply other threads:[~2020-12-01 14:52 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-30 18:17 Thomas Rodgers
2020-12-01 14:52 ` Jonathan Wakely [this message]
2020-12-01 23:45 ` Thomas Rodgers
2020-12-02 0:41 ` Jonathan Wakely
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