clang/test/CodeGenCoroutines/coro-symmetric-transfer-02.cpp

   1 // RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -std=c++20 -O1 -emit-llvm %s -o - -disable-llvm-passes | FileCheck %s
   2
   3 #include "Inputs/coroutine.h"
   4
   5 struct Task {
   6   struct promise_type {
   7     Task get_return_object() noexcept {
   8       return Task{std::coroutine_handle<promise_type>::from_promise(*this)};
   9     }
  10
  11     void return_void() noexcept {}
  12
  13     struct final_awaiter {
  14       bool await_ready() noexcept { return false; }
  15       std::coroutine_handle<> await_suspend(std::coroutine_handle<promise_type> h) noexcept {
  16         h.destroy();
  17         return {};
  18       }
  19       void await_resume() noexcept {}
  20     };
  21
  22     void unhandled_exception() noexcept {}
  23
  24     final_awaiter final_suspend() noexcept { return {}; }
  25
  26     std::suspend_always initial_suspend() noexcept { return {}; }
  27
  28     template <typename Awaitable>
  29     auto await_transform(Awaitable &&awaitable) {
  30       return awaitable.co_viaIfAsync();
  31     }
  32   };
  33
  34   using handle_t = std::coroutine_handle<promise_type>;
  35
  36   class Awaiter {
  37   public:
  38     explicit Awaiter(handle_t coro) noexcept;
  39     Awaiter(Awaiter &&other) noexcept;
  40     Awaiter(const Awaiter &) = delete;
  41     ~Awaiter();
  42
  43     bool await_ready() noexcept { return false; }
  44     handle_t await_suspend(std::coroutine_handle<> continuation) noexcept;
  45     void await_resume();
  46
  47   private:
  48     handle_t coro_;
  49   };
  50
  51   Task(handle_t coro) noexcept : coro_(coro) {}
  52
  53   handle_t coro_;
  54
  55   Task(const Task &t) = delete;
  56   Task(Task &&t) noexcept;
  57   ~Task();
  58   Task &operator=(Task t) noexcept;
  59
  60   Awaiter co_viaIfAsync();
  61 };
  62
  63 static Task foo() {
  64   co_return;
  65 }
  66
  67 Task bar() {
  68   auto mode = 2;
  69   switch (mode) {
  70   case 1:
  71     co_await foo();
  72     break;
  73   case 2:
  74     co_await foo();
  75     break;
  76   default:
  77     break;
  78   }
  79 }
  80
  81 // CHECK-LABEL: define{{.*}} void @_Z3barv
  82 // CHECK:         %[[MODE:.+]] = load i32, ptr %mode
  83 // CHECK-NEXT:    switch i32 %[[MODE]], label %{{.+}} [
  84 // CHECK-NEXT:      i32 1, label %[[CASE1:.+]]
  85 // CHECK-NEXT:      i32 2, label %[[CASE2:.+]]
  86 // CHECK-NEXT:    ]
  87
  88 // CHECK:       [[CASE1]]:
  89 // CHECK:         br i1 %{{.+}}, label %[[CASE1_AWAIT_READY:.+]], label %[[CASE1_AWAIT_SUSPEND:.+]]
  90 // CHECK:       [[CASE1_AWAIT_SUSPEND]]:
  91 // CHECK-NEXT:    %{{.+}} = call token @llvm.coro.save(ptr null)
  92 // CHECK-NEXT:    call void @llvm.coro.await.suspend.handle
  93 // CHECK-NEXT:    %{{.+}} = call i8 @llvm.coro.suspend
  94 // CHECK-NEXT:    switch i8 %{{.+}}, label %coro.ret [
  95 // CHECK-NEXT:      i8 0, label %[[CASE1_AWAIT_READY]]
  96 // CHECK-NEXT:      i8 1, label %[[CASE1_AWAIT_CLEANUP:.+]]
  97 // CHECK-NEXT:    ]
  98 // CHECK:       [[CASE1_AWAIT_CLEANUP]]:
  99 // make sure that the awaiter eventually gets cleaned up.
 100 // CHECK:         call void @{{.+Awaiter.+}}
 101
 102 // CHECK:       [[CASE2]]:
 103 // CHECK:         br i1 %{{.+}}, label %[[CASE2_AWAIT_READY:.+]], label %[[CASE2_AWAIT_SUSPEND:.+]]
 104 // CHECK:       [[CASE2_AWAIT_SUSPEND]]:
 105 // CHECK-NEXT:    %{{.+}} = call token @llvm.coro.save(ptr null)
 106 // CHECK-NEXT:    call void @llvm.coro.await.suspend.handle
 107 // CHECK-NEXT:    %{{.+}} = call i8 @llvm.coro.suspend
 108 // CHECK-NEXT:    switch i8 %{{.+}}, label %coro.ret [
 109 // CHECK-NEXT:      i8 0, label %[[CASE2_AWAIT_READY]]
 110 // CHECK-NEXT:      i8 1, label %[[CASE2_AWAIT_CLEANUP:.+]]
 111 // CHECK-NEXT:    ]
 112 // CHECK:       [[CASE2_AWAIT_CLEANUP]]:
 113 // make sure that the awaiter eventually gets cleaned up.
 114 // CHECK:         call void @{{.+Awaiter.+}}