blob: 2d635c6efa88b61b088a6f7e03bb5cce15131774 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
|
// RUN: rm -rf %t
// RUN: split-file %s %t
// RUN: %clang_cc1 -std=c++20 %t/task.cppm -I%t -emit-reduced-module-interface -o %t/task.pcm
// RUN: %clang_cc1 -std=c++20 -fprebuilt-module-path=%t %t/user.cpp -verify -fsyntax-only
//--- coroutine.h
namespace std {
template <typename R, typename...> struct coroutine_traits {
using promise_type = typename R::promise_type;
};
template <typename Promise = void> struct coroutine_handle;
template <> struct coroutine_handle<void> {
static coroutine_handle from_address(void *addr) noexcept {
coroutine_handle me;
me.ptr = addr;
return me;
}
void operator()() { resume(); }
void *address() const noexcept { return ptr; }
void resume() const { __builtin_coro_resume(ptr); }
void destroy() const { __builtin_coro_destroy(ptr); }
bool done() const { return __builtin_coro_done(ptr); }
coroutine_handle &operator=(decltype(nullptr)) {
ptr = nullptr;
return *this;
}
coroutine_handle(decltype(nullptr)) : ptr(nullptr) {}
coroutine_handle() : ptr(nullptr) {}
// void reset() { ptr = nullptr; } // add to P0057?
explicit operator bool() const { return ptr; }
protected:
void *ptr;
};
template <typename Promise> struct coroutine_handle : coroutine_handle<> {
using coroutine_handle<>::operator=;
static coroutine_handle from_address(void *addr) noexcept {
coroutine_handle me;
me.ptr = addr;
return me;
}
Promise &promise() const {
return *reinterpret_cast<Promise *>(
__builtin_coro_promise(ptr, alignof(Promise), false));
}
static coroutine_handle from_promise(Promise &promise) {
coroutine_handle p;
p.ptr = __builtin_coro_promise(&promise, alignof(Promise), true);
return p;
}
};
template <typename _PromiseT>
bool operator==(coroutine_handle<_PromiseT> const &_Left,
coroutine_handle<_PromiseT> const &_Right) noexcept {
return _Left.address() == _Right.address();
}
template <typename _PromiseT>
bool operator!=(coroutine_handle<_PromiseT> const &_Left,
coroutine_handle<_PromiseT> const &_Right) noexcept {
return !(_Left == _Right);
}
struct noop_coroutine_promise {};
template <>
struct coroutine_handle<noop_coroutine_promise> {
operator coroutine_handle<>() const noexcept {
return coroutine_handle<>::from_address(address());
}
constexpr explicit operator bool() const noexcept { return true; }
constexpr bool done() const noexcept { return false; }
constexpr void operator()() const noexcept {}
constexpr void resume() const noexcept {}
constexpr void destroy() const noexcept {}
noop_coroutine_promise &promise() const noexcept {
return *static_cast<noop_coroutine_promise *>(
__builtin_coro_promise(this->__handle_, alignof(noop_coroutine_promise), false));
}
constexpr void *address() const noexcept { return __handle_; }
private:
friend coroutine_handle<noop_coroutine_promise> noop_coroutine() noexcept;
coroutine_handle() noexcept {
this->__handle_ = __builtin_coro_noop();
}
void *__handle_ = nullptr;
};
using noop_coroutine_handle = coroutine_handle<noop_coroutine_promise>;
inline noop_coroutine_handle noop_coroutine() noexcept { return noop_coroutine_handle(); }
struct suspend_always {
bool await_ready() noexcept { return false; }
void await_suspend(coroutine_handle<>) noexcept {}
void await_resume() noexcept {}
};
struct suspend_never {
bool await_ready() noexcept { return true; }
void await_suspend(coroutine_handle<>) noexcept {}
void await_resume() noexcept {}
};
} // namespace std
//--- task.cppm
module;
#include "coroutine.h"
export module task;
export template <typename T>
struct [[clang::coro_await_elidable]] Task {
struct promise_type {
struct FinalAwaiter {
bool await_ready() const noexcept { return false; }
template <typename P>
std::coroutine_handle<> await_suspend(std::coroutine_handle<P> coro) noexcept {
if (!coro)
return std::noop_coroutine();
return coro.promise().continuation;
}
void await_resume() noexcept {}
};
Task get_return_object() noexcept {
return std::coroutine_handle<promise_type>::from_promise(*this);
}
std::suspend_always initial_suspend() noexcept { return {}; }
FinalAwaiter final_suspend() noexcept { return {}; }
void unhandled_exception() noexcept {}
void return_value(T x) noexcept {
value = x;
}
std::coroutine_handle<> continuation;
T value;
};
Task(std::coroutine_handle<promise_type> handle) : handle(handle) {}
~Task() {
if (handle)
handle.destroy();
}
struct Awaiter {
Awaiter(Task *t) : task(t) {}
bool await_ready() const noexcept { return false; }
void await_suspend(std::coroutine_handle<void> continuation) noexcept {}
T await_resume() noexcept {
return task->handle.promise().value;
}
Task *task;
};
auto operator co_await() {
return Awaiter{this};
}
private:
std::coroutine_handle<promise_type> handle;
};
inline Task<int> callee() {
co_return 1;
}
export inline Task<int> elidable() {
co_return co_await callee();
}
namespace std {
export using std::coroutine_traits;
export using std::coroutine_handle;
export using std::suspend_always;
}
//--- user.cpp
// expected-no-diagnostics
import task;
Task<int> test() {
co_return co_await elidable();
}
|
