[libcxx-commits] [clang] [libcxx] Elide suspension points via [[clang::coro_await_suspend_destroy]] (PR #152623)

[Chuanqi Xu via libcxx-commits]

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@@ -9363,6 +9363,119 @@ Example:
 }];
 }
 
+def CoroAwaitSuspendDestroyDoc : Documentation {
+  let Category = DocCatFunction;
+  let Content = [{
+
+The ``[[clang::coro_await_suspend_destroy]]`` attribute applies to an
+``await_suspend(std::coroutine_handle<Promise>)`` member function of a
+coroutine awaiter.  When applied, suspensions into the awaiter use an optimized
+call path that bypasses standard suspend intrinsics, and immediately destroys
+the suspending coro.
+
+Each annotated ``await_suspend`` member must contain a compatibility stub:
+
+.. code-block:: c++
+
+  [[clang::coro_await_suspend_destroy]]
+  void await_suspend(std::coroutine_handle<Promise> handle) {
+    await_suspend_destroy(handle.promise());
+    handle.destroy();
+  }
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ChuanqiXu9 wrote:

What does it mean? Does it say the function must be implemented as is? If yes, I feel bad for that. I prefer the previous design.

https://github.com/llvm/llvm-project/pull/152623