Get <experimental/coroutine> working in C++03.

Clang supports coroutines in all dialects; Therefore libc++ should too,
otherwise the Clang extension is unusable.

I'm not convinced extending support to C++03 is a feasible long term
plan, since as the library grows to offer things like generators it
will be come increasingly difficult to limit the implementation to C++03.

However for the time being supporting C++03 isn't a big deal.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@303963 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Eric Fiselier
2017-05-26 03:02:54 +00:00
parent c80ef6ed28
commit 4aec787d15
2 changed files with 94 additions and 33 deletions

View File

@@ -27,12 +27,12 @@ class coroutine_traits;
template <typename Promise = void>
class coroutine_handle;
// 18.11.2.7 comparison operators:
bool operator==(coroutine_handle<> x, coroutine_handle<> y) noexcept;
bool operator!=(coroutine_handle<> x, coroutine_handle<> y) noexcept;
bool operator<(coroutine_handle<> x, coroutine_handle<> y) noexcept;
bool operator<=(coroutine_handle<> x, coroutine_handle<> y) noexcept;
bool operator>=(coroutine_handle<> x, coroutine_handle<> y) noexcept;
bool operator>(coroutine_handle<> x, coroutine_handle<> y) noexcept;
bool operator==(coroutine_handle<> x, coroutine_handle<> y) _NOEXCEPT;
bool operator!=(coroutine_handle<> x, coroutine_handle<> y) _NOEXCEPT;
bool operator<(coroutine_handle<> x, coroutine_handle<> y) _NOEXCEPT;
bool operator<=(coroutine_handle<> x, coroutine_handle<> y) _NOEXCEPT;
bool operator>=(coroutine_handle<> x, coroutine_handle<> y) _NOEXCEPT;
bool operator>(coroutine_handle<> x, coroutine_handle<> y) _NOEXCEPT;
// 18.11.3 trivial awaitables
struct suspend_never;
struct suspend_always;
@@ -94,22 +94,22 @@ template <>
class _LIBCPP_TEMPLATE_VIS coroutine_handle<void> {
public:
_LIBCPP_ALWAYS_INLINE
constexpr coroutine_handle() noexcept : __handle_(nullptr) {}
_LIBCPP_CONSTEXPR coroutine_handle() _NOEXCEPT : __handle_(nullptr) {}
_LIBCPP_ALWAYS_INLINE
constexpr coroutine_handle(nullptr_t) noexcept : __handle_(nullptr) {}
_LIBCPP_CONSTEXPR coroutine_handle(nullptr_t) _NOEXCEPT : __handle_(nullptr) {}
_LIBCPP_ALWAYS_INLINE
coroutine_handle& operator=(nullptr_t) noexcept {
coroutine_handle& operator=(nullptr_t) _NOEXCEPT {
__handle_ = nullptr;
return *this;
}
_LIBCPP_ALWAYS_INLINE
constexpr void* address() const noexcept { return __handle_; }
_LIBCPP_CONSTEXPR void* address() const _NOEXCEPT { return __handle_; }
_LIBCPP_ALWAYS_INLINE
constexpr explicit operator bool() const noexcept { return __handle_; }
_LIBCPP_CONSTEXPR explicit operator bool() const _NOEXCEPT { return __handle_; }
_LIBCPP_ALWAYS_INLINE
void operator()() { resume(); }
@@ -139,14 +139,14 @@ public:
public:
_LIBCPP_ALWAYS_INLINE
static coroutine_handle from_address(void* __addr) noexcept {
static coroutine_handle from_address(void* __addr) _NOEXCEPT {
coroutine_handle __tmp;
__tmp.__handle_ = __addr;
return __tmp;
}
private:
bool __is_suspended() const noexcept {
bool __is_suspended() const _NOEXCEPT {
// FIXME actually implement a check for if the coro is suspended.
return __handle_;
}
@@ -157,27 +157,27 @@ private:
// 18.11.2.7 comparison operators:
inline _LIBCPP_ALWAYS_INLINE
bool operator==(coroutine_handle<> __x, coroutine_handle<> __y) noexcept {
bool operator==(coroutine_handle<> __x, coroutine_handle<> __y) _NOEXCEPT {
return __x.address() == __y.address();
}
inline _LIBCPP_ALWAYS_INLINE
bool operator!=(coroutine_handle<> __x, coroutine_handle<> __y) noexcept {
bool operator!=(coroutine_handle<> __x, coroutine_handle<> __y) _NOEXCEPT {
return !(__x == __y);
}
inline _LIBCPP_ALWAYS_INLINE
bool operator<(coroutine_handle<> __x, coroutine_handle<> __y) noexcept {
bool operator<(coroutine_handle<> __x, coroutine_handle<> __y) _NOEXCEPT {
return less<void*>()(__x.address(), __y.address());
}
inline _LIBCPP_ALWAYS_INLINE
bool operator>(coroutine_handle<> __x, coroutine_handle<> __y) noexcept {
bool operator>(coroutine_handle<> __x, coroutine_handle<> __y) _NOEXCEPT {
return __y < __x;
}
inline _LIBCPP_ALWAYS_INLINE
bool operator<=(coroutine_handle<> __x, coroutine_handle<> __y) noexcept {
bool operator<=(coroutine_handle<> __x, coroutine_handle<> __y) _NOEXCEPT {
return !(__x > __y);
}
inline _LIBCPP_ALWAYS_INLINE
bool operator>=(coroutine_handle<> __x, coroutine_handle<> __y) noexcept {
bool operator>=(coroutine_handle<> __x, coroutine_handle<> __y) _NOEXCEPT {
return !(__x < __y);
}
@@ -185,11 +185,15 @@ template <typename _Promise>
class _LIBCPP_TEMPLATE_VIS coroutine_handle : public coroutine_handle<> {
using _Base = coroutine_handle<>;
public:
#ifndef _LIBCPP_CXX03_LANG
// 18.11.2.1 construct/reset
using coroutine_handle<>::coroutine_handle;
#else
_LIBCPP_ALWAYS_INLINE coroutine_handle() _NOEXCEPT : _Base() {}
_LIBCPP_ALWAYS_INLINE coroutine_handle(nullptr_t) _NOEXCEPT : _Base(nullptr) {}
#endif
_LIBCPP_INLINE_VISIBILITY
coroutine_handle& operator=(nullptr_t) noexcept {
coroutine_handle& operator=(nullptr_t) _NOEXCEPT {
_Base::operator=(nullptr);
return *this;
}
@@ -197,42 +201,42 @@ public:
_LIBCPP_INLINE_VISIBILITY
_Promise& promise() const {
return *reinterpret_cast<_Promise*>(
__builtin_coro_promise(this->__handle_, alignof(_Promise), false));
__builtin_coro_promise(this->__handle_, __alignof(_Promise), false));
}
public:
_LIBCPP_ALWAYS_INLINE
static coroutine_handle from_address(void* __addr) noexcept {
static coroutine_handle from_address(void* __addr) _NOEXCEPT {
coroutine_handle __tmp;
__tmp.__handle_ = __addr;
return __tmp;
}
_LIBCPP_ALWAYS_INLINE
static coroutine_handle from_promise(_Promise& __promise) noexcept {
static coroutine_handle from_promise(_Promise& __promise) _NOEXCEPT {
coroutine_handle __tmp;
__tmp.__handle_ = __builtin_coro_promise(_VSTD::addressof(__promise),
alignof(_Promise), true);
__alignof(_Promise), true);
return __tmp;
}
};
struct _LIBCPP_TYPE_VIS suspend_never {
_LIBCPP_ALWAYS_INLINE
bool await_ready() const noexcept { return true; }
bool await_ready() const _NOEXCEPT { return true; }
_LIBCPP_ALWAYS_INLINE
void await_suspend(coroutine_handle<>) const noexcept {}
void await_suspend(coroutine_handle<>) const _NOEXCEPT {}
_LIBCPP_ALWAYS_INLINE
void await_resume() const noexcept {}
void await_resume() const _NOEXCEPT {}
};
struct _LIBCPP_TYPE_VIS suspend_always {
_LIBCPP_ALWAYS_INLINE
bool await_ready() const noexcept { return false; }
bool await_ready() const _NOEXCEPT { return false; }
_LIBCPP_ALWAYS_INLINE
void await_suspend(coroutine_handle<>) const noexcept {}
void await_suspend(coroutine_handle<>) const _NOEXCEPT {}
_LIBCPP_ALWAYS_INLINE
void await_resume() const noexcept {}
void await_resume() const _NOEXCEPT {}
};
_LIBCPP_END_NAMESPACE_EXPERIMENTAL_COROUTINES
@@ -243,8 +247,8 @@ template <class _Tp>
struct hash<_VSTD_CORO::coroutine_handle<_Tp> > {
using __arg_type = _VSTD_CORO::coroutine_handle<_Tp>;
_LIBCPP_INLINE_VISIBILITY
size_t operator()(__arg_type const& __v) const noexcept
{return hash<void*>{}(__v.address());}
size_t operator()(__arg_type const& __v) const _NOEXCEPT
{return hash<void*>()(__v.address());}
};
_LIBCPP_END_NAMESPACE_STD

View File

@@ -0,0 +1,57 @@
// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// REQUIRES: fcoroutines-ts
// RUN: %build -fcoroutines-ts
// RUN: %run
// A simple "breathing" test that checks that <experimental/coroutine>
// can be parsed and used in all dialects, including C++03 in order to match
// Clang's behavior.
#include <experimental/coroutine>
namespace coro = std::experimental::coroutines_v1;
coro::suspend_always sa;
coro::suspend_never sn;
struct MyFuture {
struct promise_type {
typedef coro::coroutine_handle<promise_type> HandleT;
coro::suspend_always initial_suspend() { return sa; }
coro::suspend_never final_suspend() { return sn; }
coro::suspend_never yield_value(int) { return sn; }
MyFuture get_return_object() {
MyFuture f(HandleT::from_address(this));
return f;
}
void return_void() {}
void unhandled_exception() {}
};
typedef promise_type::HandleT HandleT;
MyFuture() : p() {}
MyFuture(HandleT h) : p(h) {}
private:
coro::coroutine_handle<promise_type> p;
};
MyFuture test_coro() {
co_await sn;
co_yield 42;
co_return;
}
int main()
{
MyFuture f = test_coro();
}