xref: /llvm-project/clang/test/CodeGenCoroutines/coro-cleanup.cpp (revision 130e93cc26ca9d3ac50ec5a92e3109577ca2e702)
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(
f()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(
g()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 }
105