clang/test/CodeGenCoroutines/coro-symmetric-transfer-01.cpp

   1 // RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -std=c++20 -O0 -emit-llvm %s -o - -disable-llvm-passes | FileCheck %s
   2 // RUN: %clang -std=c++20 -O0 -emit-llvm -c  %s -o %t -Xclang -disable-llvm-passes && %clang -c %t
   3
   4 #include "Inputs/coroutine.h"
   5
   6 struct detached_task {
   7   struct promise_type {
   8     detached_task get_return_object() noexcept {
   9       return detached_task{std::coroutine_handle<promise_type>::from_promise(*this)};
  10     }
  11
  12     void return_void() noexcept {}
  13
  14     struct final_awaiter {
  15       bool await_ready() noexcept { return false; }
  16       std::coroutine_handle<> await_suspend(std::coroutine_handle<promise_type> h) noexcept {
  17         h.destroy();
  18         return {};
  19       }
  20       void await_resume() noexcept {}
  21     };
  22
  23     void unhandled_exception() noexcept {}
  24
  25     final_awaiter final_suspend() noexcept { return {}; }
  26
  27     std::suspend_always initial_suspend() noexcept { return {}; }
  28   };
  29
  30   ~detached_task() {
  31     if (coro_) {
  32       coro_.destroy();
  33       coro_ = {};
  34     }
  35   }
  36
  37   void start() && {
  38     auto tmp = coro_;
  39     coro_ = {};
  40     tmp.resume();
  41   }
  42
  43   std::coroutine_handle<promise_type> coro_;
  44 };
  45
  46 detached_task foo() {
  47   co_return;
  48 }
  49
  50 // check that the lifetime of the coroutine handle used to obtain the address is contained within single basic block, and hence does not live across suspension points.
  51 // CHECK-LABEL: final.suspend:
  52 // CHECK:         %{{.+}} = call token @llvm.coro.save(ptr null)
  53 // CHECK:         call void @llvm.lifetime.start.p0(i64 8, ptr %[[HDL:.+]])
  54 // CHECK:         %[[CALL:.+]] = call ptr @_ZN13detached_task12promise_type13final_awaiter13await_suspendESt16coroutine_handleIS0_E(
  55 // CHECK:         %[[HDL_CAST2:.+]] = getelementptr inbounds %"struct.std::coroutine_handle.0", ptr %[[HDL]], i32 0, i32 0
  56 // CHECK:         store ptr %[[CALL]], ptr %[[HDL_CAST2]], align 8
  57 // CHECK:         %[[HDL_TRANSFER:.+]] = call noundef ptr @_ZNKSt16coroutine_handleIvE7addressEv(ptr noundef {{.*}}%[[HDL]])
  58 // CHECK:         call void @llvm.lifetime.end.p0(i64 8, ptr %[[HDL]])
  59 // CHECK:         call void @llvm.coro.resume(ptr %[[HDL_TRANSFER]])