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* [gcc r11-7677] coroutines : Convert await_ready () expressions to bool [PR99047].
@ 2021-03-15 16:00 Iain D Sandoe
0 siblings, 0 replies; only message in thread
From: Iain D Sandoe @ 2021-03-15 16:00 UTC (permalink / raw)
To: gcc-cvs
https://gcc.gnu.org/g:541840b891d61ea70cddd046c96698bb70d7f52c
commit r11-7677-g541840b891d61ea70cddd046c96698bb70d7f52c
Author: Iain Sandoe <iain@sandoe.co.uk>
Date: Sun Mar 14 14:42:52 2021 +0000
coroutines : Convert await_ready () expressions to bool [PR99047].
The awaiter.await_ready() should be converted per [expr.await]/3
(3.6) await-ready is the expression e.await_ready(), contextually
converted to bool.
gcc/cp/ChangeLog:
PR c++/99047
* coroutines.cc (expand_one_await_expression): If the
await_ready() expression is not a boolean then convert it
as required.
gcc/testsuite/ChangeLog:
PR c++/99047
* g++.dg/coroutines/pr99047.C: New test.
Diff:
---
gcc/cp/coroutines.cc | 8 ++-
gcc/testsuite/g++.dg/coroutines/pr99047.C | 83 +++++++++++++++++++++++++++++++
2 files changed, 90 insertions(+), 1 deletion(-)
diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc
index ea714da146b..51984efe2fd 100644
--- a/gcc/cp/coroutines.cc
+++ b/gcc/cp/coroutines.cc
@@ -1586,7 +1586,13 @@ expand_one_await_expression (tree *stmt, tree *await_expr, void *d)
/* Use the await_ready() call to test if we need to suspend. */
tree ready_cond = TREE_VEC_ELT (awaiter_calls, 0); /* await_ready(). */
- ready_cond = build1_loc (loc, TRUTH_NOT_EXPR, boolean_type_node, ready_cond);
+ /* Convert to bool, if necessary. */
+ if (TREE_CODE (TREE_TYPE (ready_cond)) != BOOLEAN_TYPE)
+ ready_cond = cp_convert (boolean_type_node, ready_cond,
+ tf_warning_or_error);
+ /* Be aggressive in folding here, since there are a significant number of
+ cases where the ready condition is constant. */
+ ready_cond = invert_truthvalue_loc (loc, ready_cond);
ready_cond
= build1_loc (loc, CLEANUP_POINT_EXPR, boolean_type_node, ready_cond);
diff --git a/gcc/testsuite/g++.dg/coroutines/pr99047.C b/gcc/testsuite/g++.dg/coroutines/pr99047.C
new file mode 100644
index 00000000000..124633a08e6
--- /dev/null
+++ b/gcc/testsuite/g++.dg/coroutines/pr99047.C
@@ -0,0 +1,83 @@
+#include <optional>
+#include <coroutine>
+
+template <typename T>
+struct [[nodiscard]] task {
+ struct promise_type {
+ std::suspend_always initial_suspend() {
+ return {};
+ }
+ auto final_suspend() noexcept {
+ struct awaiter {
+#if 1
+ std::false_type await_ready() noexcept {
+ return {};
+ }
+#else
+ bool await_ready() noexcept {
+ return false;
+ }
+#endif
+ std::coroutine_handle<> await_suspend(std::coroutine_handle<>) noexcept {
+ return next;
+ }
+ void await_resume() noexcept {
+ }
+ std::coroutine_handle<> next;
+ };
+ return awaiter{next};
+ }
+
+ void unhandled_exception() noexcept {
+ std::terminate();
+ }
+ auto get_return_object() {
+ return task(this);
+ }
+ auto coro() {
+ return std::coroutine_handle<promise_type>::from_promise(*this);
+ }
+ void return_value(T val) {
+ result.emplace(std::move(val));
+ }
+
+ std::coroutine_handle<> next;
+ std::optional<T> result;
+ };
+
+ task(task&& source) : p(std::exchange(source.p, nullptr)) {}
+ explicit task(promise_type* p) : p(p) {}
+ ~task() {
+ if (p)
+ p->coro().destroy();
+ }
+
+ bool await_ready() noexcept {
+ return p->coro().done();
+ }
+ std::coroutine_handle<> await_suspend(std::coroutine_handle<> next) noexcept {
+ p->next = next;
+ return p->coro();
+ }
+ const T& await_resume() const& noexcept {
+ return *p->result;
+ }
+
+ promise_type* p;
+};
+
+task<int> five() {
+ co_return 5;
+}
+
+task<int> six() {
+ co_return co_await five() + 1;
+}
+
+
+int main() {
+ auto task = six();
+ task.p->next = std::noop_coroutine();
+ task.p->coro().resume();
+ return *task.p->result;
+}
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2021-03-15 16:00 [gcc r11-7677] coroutines : Convert await_ready () expressions to bool [PR99047] Iain D Sandoe
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