clang/test/CodeGenCoroutines/pr65018.cpp

   1 // RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -std=c++20 \
   2 // RUN:      -O1 -emit-llvm %s -o - | FileCheck %s
   3
   4 #include "Inputs/coroutine.h"
   5
   6 // A simple awaiter type with an await_suspend method that can't be
   7 // inlined.
   8 struct Awaiter {
   9   const int& x;
  10
  11   bool await_ready() { return false; }
  12   std::coroutine_handle<> await_suspend(const std::coroutine_handle<> h);
  13   void await_resume() {}
  14 };
  15
  16 struct MyTask {
  17   // A lazy promise with an await_transform method that supports awaiting
  18   // integer references using the Awaiter struct above.
  19   struct promise_type {
  20     MyTask get_return_object() {
  21       return MyTask{
  22           std::coroutine_handle<promise_type>::from_promise(*this),
  23       };
  24     }
  25
  26     std::suspend_always initial_suspend() { return {}; }
  27     std::suspend_always final_suspend() noexcept { return {}; }
  28     void unhandled_exception();
  29
  30     auto await_transform(const int& x) { return Awaiter{x}; }
  31   };
  32
  33   std::coroutine_handle<> h;
  34 };
  35
  36 // A global array of integers.
  37 int g_array[32];
  38
  39 // A coroutine that awaits each integer in the global array.
  40 MyTask FooBar() {
  41   for (const int& x : g_array) {
  42     co_await x;
  43   }
  44 }
  45
  46 // CHECK: %[[RET:.+]] = {{.*}}call{{.*}}@_ZN7Awaiter13await_suspendESt16coroutine_handleIvE
  47 // CHECK: %[[RESUME_ADDR:.+]] = load ptr, ptr %[[RET]],
  48 // CHECK: musttail call fastcc void %[[RESUME_ADDR]]({{.*}}%[[RET]]
  49 // CHECK: ret
  50