clang/test/CodeGenCoroutines/coro-cleanup.cpp

   1 // Verify that coroutine promise and allocated memory are freed up on exception.
   2 // RUN: %clang_cc1 -std=c++20 -triple=x86_64-unknown-linux-gnu -emit-llvm -o - %s -fexceptions -fcxx-exceptions -disable-llvm-passes | FileCheck %s --check-prefixes=CHECK,THROWEND
   3 // RUN: %clang_cc1 -std=c++20 -triple=x86_64-unknown-linux-gnu -emit-llvm -o - %s -fexceptions -fcxx-exceptions -fassume-nothrow-exception-dtor -disable-llvm-passes | FileCheck %s --check-prefixes=CHECK,NOTHROWEND
   4
   5 namespace std {
   6 template <typename... T> struct coroutine_traits;
   7
   8 template <class Promise = void> struct coroutine_handle {
   9   coroutine_handle() = default;
  10   static coroutine_handle from_address(void *) noexcept;
  11 };
  12 template <> struct coroutine_handle<void> {
  13   static coroutine_handle from_address(void *) noexcept;
  14   coroutine_handle() = default;
  15   template <class PromiseType>
  16   coroutine_handle(coroutine_handle<PromiseType>) noexcept;
  17 };
  18 } // namespace std
  19
  20 struct suspend_always {
  21   bool await_ready() noexcept;
  22   void await_suspend(std::coroutine_handle<>) noexcept;
  23   void await_resume() noexcept;
  24 };
  25
  26 template <> struct std::coroutine_traits<void> {
  27   struct promise_type {
  28     void get_return_object() noexcept;
  29     suspend_always initial_suspend() noexcept;
  30     suspend_always final_suspend() noexcept;
  31     void return_void() noexcept;
  32     promise_type();
  33     ~promise_type();
  34     void unhandled_exception() noexcept;
  35   };
  36 };
  37
  38 struct Cleanup { ~Cleanup(); };
  39 void may_throw();
  40
  41 // CHECK-LABEL: define{{.*}} void @_Z1fv(
  42 void f() {
  43   // CHECK: call noalias noundef nonnull ptr @_Znwm(i64
  44
  45   // If promise constructor throws, check that we free the memory.
  46
  47   // CHECK: invoke void @_ZNSt16coroutine_traitsIJvEE12promise_typeC1Ev(
  48   // CHECK-NEXT: to label %{{.+}} unwind label %[[DeallocPad:.+]]
  49
  50   // CHECK: [[DeallocPad]]:
  51   // CHECK-NEXT: landingpad
  52   // CHECK-NEXT:   cleanup
  53   // THROWEND:        br label %[[Dealloc:.+]]
  54   // NOTHROWEND:      icmp ne ptr %[[#]], null
  55   // NOTHROWEND-NEXT: br i1 %[[#]], label %[[Dealloc:.+]], label
  56
  57   Cleanup cleanup;
  58   may_throw();
  59
  60   // if may_throw throws, check that we destroy the promise and free the memory.
  61
  62   // CHECK: invoke void @_Z9may_throwv(
  63   // CHECK-NEXT: to label %{{.+}} unwind label %[[CatchPad:.+]]
  64
  65   // CHECK: [[CatchPad]]:
  66   // CHECK-NEXT:  landingpad
  67   // CHECK-NEXT:       catch ptr null
  68   // CHECK:  call void @_ZN7CleanupD1Ev(
  69   // CHECK:  br label %[[Catch:.+]]
  70
  71   // CHECK: [[Catch]]:
  72   // CHECK:    call ptr @__cxa_begin_catch(
  73   // CHECK:    call void @_ZNSt16coroutine_traitsIJvEE12promise_type19unhandled_exceptionEv(
  74   // THROWEND:        invoke void @__cxa_end_catch()
  75   // THROWEND-NEXT:     to label %[[Cont:.+]] unwind
  76   // NOTHROWEND:      call void @__cxa_end_catch()
  77   // NOTHROWEND-NEXT:   br label %[[Cont2:.+]]
  78
  79   // THROWEND:      [[Cont]]:
  80   // THROWEND-NEXT:   br label %[[Cont2:.+]]
  81   // CHECK:         [[Cont2]]:
  82   // CHECK-NEXT:      br label %[[Cleanup:.+]]
  83
  84   // CHECK: [[Cleanup]]:
  85   // CHECK: call void @_ZNSt16coroutine_traitsIJvEE12promise_typeD1Ev(
  86   // CHECK: %[[Mem0:.+]] = call ptr @llvm.coro.free(
  87   // CHECK: %[[SIZE:.+]] = call i64 @llvm.coro.size.i64()
  88   // CHECK: call void @_ZdlPvm(ptr noundef %[[Mem0]], i64 noundef %[[SIZE]])
  89
  90   // CHECK: [[Dealloc]]:
  91   // THROWEND:   %[[Mem:.+]] = call ptr @llvm.coro.free(
  92   // THROWEND:   %[[SIZE:.+]] = call i64 @llvm.coro.size.i64()
  93   // THROWEND:   call void @_ZdlPvm(ptr noundef %[[Mem]], i64 noundef %[[SIZE]])
  94
  95   co_return;
  96 }
  97
  98 // CHECK-LABEL: define{{.*}} void @_Z1gv(
  99 void g() {
 100   for (;;)
 101     co_await suspend_always{};
 102   // Since this is the endless loop there should be no fallthrough handler (call to 'return_void').
 103   // CHECK-NOT: call void @_ZNSt16coroutine_traitsIJvEE12promise_type11return_voidEv
 104 }