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author | Iain Sandoe <iain@sandoe.co.uk> | 2021-03-14 14:42:52 +0000 |
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committer | Iain Sandoe <iain@sandoe.co.uk> | 2021-03-15 15:57:42 +0000 |
commit | 541840b891d61ea70cddd046c96698bb70d7f52c (patch) | |
tree | cd8f9ae7496569d1fbd22420faaaff24f65a1eba | |
parent | 020b286c769f4dc8a6b45491351f6bc2e69d7a7f (diff) | |
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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.
-rw-r--r-- | gcc/cp/coroutines.cc | 8 | ||||
-rw-r--r-- | gcc/testsuite/g++.dg/coroutines/pr99047.C | 83 |
2 files changed, 90 insertions, 1 deletions
diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc index ea714da..51984ef 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 0000000..124633a --- /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; +} |