clang/test/CodeGenCoroutines/pr65054.cpp

   1 // The output of O0 is highly redundant and hard to test. Also it is not good
   2 // limit the output of O0. So we test the optimized output from O0. The idea
   3 // is the optimizations shouldn't change the semantics of the program.
   4 // RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -std=c++20 \
   5 // RUN:      -O0 -emit-llvm %s -o - -disable-O0-optnone \
   6 // RUN:      | opt -passes='sroa,mem2reg,simplifycfg' -S | FileCheck %s --check-prefix=CHECK-O0
   7
   8 #include "Inputs/coroutine.h"
   9
  10 // A simple awaiter type with an await_suspend method that can't be
  11 // inlined.
  12 struct Awaiter {
  13   const int& x;
  14
  15   bool await_ready() { return false; }
  16   std::coroutine_handle<> await_suspend(const std::coroutine_handle<> h);
  17   void await_resume() {}
  18 };
  19
  20 struct MyTask {
  21   // A lazy promise with an await_transform method that supports awaiting
  22   // integer references using the Awaiter struct above.
  23   struct promise_type {
  24     MyTask get_return_object() {
  25       return MyTask{
  26           std::coroutine_handle<promise_type>::from_promise(*this),
  27       };
  28     }
  29
  30     std::suspend_always initial_suspend() { return {}; }
  31     std::suspend_always final_suspend() noexcept { return {}; }
  32     void unhandled_exception();
  33
  34     auto await_transform(const int& x) { return Awaiter{x}; }
  35   };
  36
  37   std::coroutine_handle<> h;
  38 };
  39
  40 // A global array of integers.
  41 int g_array[32];
  42
  43 // A coroutine that awaits each integer in the global array.
  44 MyTask FooBar() {
  45   for (const int& x : g_array) {
  46     co_await x;
  47   }
  48 }
  49
  50 // CHECK-O0: define{{.*}}@_Z6FooBarv.resume
  51 // CHECK-O0: call{{.*}}@_Z6FooBarv.__await_suspend_wrapper__await(
  52 // CHECK-O0-NOT: store
  53 // CHECK-O0: ret void