@@ -708,6 +708,7 @@ experimental_headers = \
${experimental_srcdir}/array \
${experimental_srcdir}/buffer \
${experimental_srcdir}/chrono \
+ ${experimental_srcdir}/coroutine \
${experimental_srcdir}/deque \
${experimental_srcdir}/executor \
${experimental_srcdir}/forward_list \
@@ -1052,6 +1052,7 @@ experimental_headers = \
${experimental_srcdir}/array \
${experimental_srcdir}/buffer \
${experimental_srcdir}/chrono \
+ ${experimental_srcdir}/coroutine \
${experimental_srcdir}/deque \
${experimental_srcdir}/executor \
${experimental_srcdir}/forward_list \
new file mode 100644
@@ -0,0 +1,268 @@
+// <experimental/coroutine> -*- C++ -*-
+
+// Copyright (C) 2019 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.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+// <http://www.gnu.org/licenses/>.
+
+/** @file experimental/coroutine
+ * This is an experimental C++ Library header against the C++20 CD n4835.
+ * @ingroup coroutine-ts
+ */
+
+#ifndef _GLIBCXX_EXPERIMENTAL_COROUTINE
+#define _GLIBCXX_EXPERIMENTAL_COROUTINE 1
+
+#pragma GCC system_header
+
+// It is very likely that earlier versions would work, but they are untested.
+#if __cplusplus >= 201402L
+
+#include <bits/c++config.h>
+
+#if __cplusplus > 201703L && __cpp_impl_three_way_comparison >= 201907L
+# include <compare>
+# define THE_SPACESHIP_HAS_LANDED 1
+#else
+# include <bits/stl_function.h>
+# define THE_SPACESHIP_HAS_LANDED 0
+#endif
+
+namespace std _GLIBCXX_VISIBILITY (default)
+{
+ _GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+#if __cpp_coroutines
+
+ namespace experimental {
+ inline namespace coroutines_n4835 {
+
+ // [coroutine.traits]
+ // [coroutine.traits.primary]
+ // 17.12.2 coroutine traits
+ template <typename _R, typename...> struct coroutine_traits
+ {
+ using promise_type = typename _R::promise_type;
+ };
+
+ // 17.12.3 Class template coroutine_handle
+ // [coroutine.handle]
+ template <typename _Promise = void> struct coroutine_handle;
+
+ template <> struct coroutine_handle<void>
+ {
+ public:
+ // 17.12.3.1, construct/reset
+ constexpr coroutine_handle () noexcept : __fr_ptr (0) {}
+ constexpr coroutine_handle (decltype (nullptr) __h) noexcept
+ : __fr_ptr (__h)
+ {}
+ coroutine_handle &operator= (decltype (nullptr)) noexcept
+ {
+ __fr_ptr = nullptr;
+ return *this;
+ }
+
+ public:
+ // 17.12.3.2, export/import
+ constexpr void *address () const noexcept { return __fr_ptr; }
+ constexpr static coroutine_handle from_address (void *__a) noexcept
+ {
+ coroutine_handle __self;
+ __self.__fr_ptr = __a;
+ return __self;
+ }
+
+ public:
+ // 17.12.3.3, observers
+ constexpr explicit operator bool () const noexcept
+ {
+ return bool(__fr_ptr);
+ }
+ bool done () const noexcept { return __builtin_coro_done (__fr_ptr); }
+ // 17.12.3.4, resumption
+ void operator() () const { resume (); }
+ void resume () const { __builtin_coro_resume (__fr_ptr); }
+ void destroy () const { __builtin_coro_destroy (__fr_ptr); }
+
+ protected:
+ void *__fr_ptr;
+ };
+
+ // [coroutine.handle.compare]
+ // 17.12.3.6 Comparison operators
+ constexpr bool operator== (coroutine_handle<> __a,
+ coroutine_handle<> __b) noexcept
+ {
+ return __a.address () == __b.address ();
+ }
+
+#if THE_SPACESHIP_HAS_LANDED
+ constexpr strong_ordering
+ operator<=> (coroutine_handle<> __a, coroutine_handle<> __b) noexcept;
+#else
+ // These are from the TS.
+ constexpr bool operator!= (coroutine_handle<> __a,
+ coroutine_handle<> __b) noexcept
+ {
+ return !(__a == __b);
+ }
+
+ constexpr bool operator< (coroutine_handle<> __a,
+ coroutine_handle<> __b) noexcept
+ {
+ return less<void *> () (__a.address (), __b.address ());
+ }
+
+ constexpr bool operator> (coroutine_handle<> __a,
+ coroutine_handle<> __b) noexcept
+ {
+ return __b < __a;
+ }
+
+ constexpr bool operator<= (coroutine_handle<> __a,
+ coroutine_handle<> __b) noexcept
+ {
+ return !(__a > __b);
+ }
+
+ constexpr bool operator>= (coroutine_handle<> __a,
+ coroutine_handle<> __b) noexcept
+ {
+ return !(__a < __b);
+ }
+#endif
+
+ template <class _Promise> struct coroutine_handle : coroutine_handle<>
+ {
+ // 17.12.3.1, construct/reset
+ using coroutine_handle<>::coroutine_handle;
+ static coroutine_handle from_promise (_Promise &p)
+ {
+ coroutine_handle __self;
+ __self.__fr_ptr
+ = __builtin_coro_promise ((char *) &p, __alignof(_Promise), true);
+ return __self;
+ }
+ coroutine_handle &operator= (decltype (nullptr)) noexcept
+ {
+ coroutine_handle<>::operator= (nullptr);
+ return *this;
+ }
+ // 17.12.3.2, export/import
+ constexpr static coroutine_handle from_address (void *__a)
+ {
+ coroutine_handle __self;
+ __self.__fr_ptr = __a;
+ return __self;
+ }
+ // 17.12.3.5, promise accesss
+ _Promise &promise () const
+ {
+ void *__t
+ = __builtin_coro_promise (this->__fr_ptr, __alignof(_Promise), false);
+ return *static_cast<_Promise *> (__t);
+ }
+ };
+
+ // [coroutine.noop]
+ struct noop_coroutine_promise
+ {
+ };
+
+ void __dummy_resume_destroy () __attribute__ ((__weak__));
+ void __dummy_resume_destroy () {}
+
+ struct __noop_coro_frame
+ {
+ void (*__r) () = __dummy_resume_destroy;
+ void (*__d) () = __dummy_resume_destroy;
+ struct noop_coroutine_promise __p;
+ } __noop_coro_fr __attribute__ ((__weak__));
+
+ // [coroutine.promise.noop]
+ // 17.12.4.1 Class noop_coroutine_promise
+ template <>
+ class coroutine_handle<noop_coroutine_promise> : public coroutine_handle<>
+ {
+ using _Promise = noop_coroutine_promise;
+
+ public:
+ // // 17.12.4.2.1, observers
+ constexpr explicit operator bool () const noexcept { return true; }
+ constexpr bool done () const noexcept { return false; }
+
+ // 17.12.4.2.2, resumption
+ void operator() () const noexcept {}
+ void resume () const noexcept {}
+ void destroy () const noexcept {}
+
+ // 17.12.4.2.3, promise access
+ _Promise &promise () const
+ {
+ return *static_cast<_Promise *> (
+ __builtin_coro_promise (this->__fr_ptr, __alignof(_Promise), false));
+ }
+
+ // 17.12.4.2.4, address
+ // constexpr void* address() const noexcept;
+ private:
+ friend coroutine_handle<noop_coroutine_promise> noop_coroutine () noexcept;
+
+ coroutine_handle () noexcept { this->__fr_ptr = (void *) &__noop_coro_fr; }
+ };
+
+ using noop_coroutine_handle = coroutine_handle<noop_coroutine_promise>;
+
+ inline noop_coroutine_handle noop_coroutine () noexcept
+ {
+ return noop_coroutine_handle ();
+ }
+
+ // [coroutine.trivial.awaitables]
+ // 17.12.5 Trivial awaitables
+
+ struct suspend_always
+ {
+ bool await_ready () { return false; }
+ void await_suspend (coroutine_handle<>) {}
+ void await_resume () {}
+ };
+
+ struct suspend_never
+ {
+ bool await_ready () { return true; }
+ void await_suspend (coroutine_handle<>) {}
+ void await_resume () {}
+ };
+
+ } // namespace coroutines_n4835
+ } // namespace experimental
+
+#else
+#error "the coroutine header requires -fcoroutines"
+#endif
+
+ _GLIBCXX_END_NAMESPACE_VERSION
+} // namespace std_GLIBCXX_VISIBILITY(default)
+
+#endif // C++14
+
+#endif // _GLIBCXX_EXPERIMENTAL_COROUTINE