51d5d7bbae
One of the main user of these kind of coroutines is swift. There yield-once (`retcon.once`) coroutines are used to temporary "expose" pointers to internal fields of various objects creating borrow scopes. However, in some cases it might be useful also to allow these coroutines to produce a normal result, but there is no convenient way to represent this (as compared to switched-resume kind of coroutines where C++ `co_return` is transformed to a member / callback call on promise object). The extension is simple: we allow continuation function to have a non-void result and accept optional extra arguments via a special `llvm.coro.end.result` intrinsic that would essentially forward them as normal results.
87 lines
3.3 KiB
C++
87 lines
3.3 KiB
C++
// RUN: %clang_cc1 -std=c++20 -triple=x86_64-pc-windows-msvc18.0.0 -emit-llvm %s -o - -fexceptions -fcxx-exceptions -disable-llvm-passes | FileCheck %s
|
|
// RUN: %clang_cc1 -std=c++20 -triple=x86_64-unknown-linux-gnu -emit-llvm -o - %s -fexceptions -fcxx-exceptions -disable-llvm-passes | FileCheck --check-prefix=CHECK-LPAD %s
|
|
|
|
namespace std {
|
|
template <typename R, typename... T> struct coroutine_traits {
|
|
using promise_type = typename R::promise_type;
|
|
};
|
|
|
|
template <class Promise = void> struct coroutine_handle;
|
|
|
|
template <> struct coroutine_handle<void> {
|
|
static coroutine_handle from_address(void *) noexcept;
|
|
coroutine_handle() = default;
|
|
template <class PromiseType>
|
|
coroutine_handle(coroutine_handle<PromiseType>) noexcept;
|
|
};
|
|
template <class Promise> struct coroutine_handle: coroutine_handle<void> {
|
|
coroutine_handle() = default;
|
|
static coroutine_handle from_address(void *) noexcept;
|
|
};
|
|
} // namespace std
|
|
|
|
struct suspend_always {
|
|
bool await_ready() noexcept;
|
|
void await_suspend(std::coroutine_handle<>) noexcept;
|
|
void await_resume() noexcept;
|
|
};
|
|
|
|
struct coro_t {
|
|
struct promise_type {
|
|
coro_t get_return_object() noexcept;
|
|
suspend_always initial_suspend() noexcept;
|
|
suspend_always final_suspend() noexcept;
|
|
void return_void() noexcept;
|
|
void unhandled_exception() noexcept;
|
|
};
|
|
};
|
|
|
|
struct Cleanup { ~Cleanup(); };
|
|
void may_throw();
|
|
|
|
coro_t f() {
|
|
Cleanup x;
|
|
may_throw();
|
|
co_return;
|
|
}
|
|
|
|
// CHECK: @"?f@@YA?AUcoro_t@@XZ"(
|
|
// CHECK: invoke void @"?may_throw@@YAXXZ"()
|
|
// CHECK: to label %[[CONT:.+]] unwind label %[[EHCLEANUP:.+]]
|
|
// CHECK: [[EHCLEANUP]]:
|
|
// CHECK: %[[INNERPAD:.+]] = cleanuppad within none []
|
|
// CHECK: call void @"??1Cleanup@@QEAA@XZ"(
|
|
// CHECK: cleanupret from %{{.+}} unwind label %[[CATCHDISPATCH:.+]]
|
|
|
|
// CHECK: [[CATCHDISPATCH]]:
|
|
// CHECK: catchswitch within none [label %[[CATCHPAD:.+]]] unwind label %[[COROENDBB:.+]]
|
|
// CHECK: [[CATCHPAD]]:
|
|
// CHECK: call void @"?unhandled_exception@promise_type@coro_t@@QEAAXXZ"
|
|
|
|
// CHECK: [[COROENDBB]]:
|
|
// CHECK-NEXT: %[[CLPAD:.+]] = cleanuppad within none
|
|
// CHECK-NEXT: call i1 @llvm.coro.end(ptr null, i1 true, token none) [ "funclet"(token %[[CLPAD]]) ]
|
|
// CHECK-NEXT: cleanupret from %[[CLPAD]] unwind label
|
|
|
|
// CHECK-LPAD: @_Z1fv(
|
|
// CHECK-LPAD: invoke void @_Z9may_throwv()
|
|
// CHECK-LPAD: to label %[[CONT:.+]] unwind label %[[EHCLEANUP:.+]]
|
|
// CHECK-LPAD: [[EHCLEANUP]]:
|
|
// CHECK-LPAD: landingpad { ptr, i32 }
|
|
// CHECK-LPAD: catch
|
|
// CHECK-LPAD: call void @_ZN7CleanupD1Ev(
|
|
// CHECK-LPAD: call ptr @__cxa_begin_catch
|
|
// CHECK-LPAD: call void @_ZN6coro_t12promise_type19unhandled_exceptionEv
|
|
// CHECK-LPAD: invoke void @__cxa_end_catch()
|
|
// CHECK-LPAD: to label %{{.+}} unwind label %[[UNWINDBB:.+]]
|
|
|
|
// CHECK-LPAD: [[UNWINDBB]]:
|
|
// CHECK-LPAD: %[[I1RESUME:.+]] = call i1 @llvm.coro.end(ptr null, i1 true, token none)
|
|
// CHECK-LPAD: br i1 %[[I1RESUME]], label %[[EHRESUME:.+]], label
|
|
// CHECK-LPAD: [[EHRESUME]]:
|
|
// CHECK-LPAD-NEXT: %[[exn:.+]] = load ptr, ptr %exn.slot, align 8
|
|
// CHECK-LPAD-NEXT: %[[sel:.+]] = load i32, ptr %ehselector.slot, align 4
|
|
// CHECK-LPAD-NEXT: %[[val1:.+]] = insertvalue { ptr, i32 } poison, ptr %[[exn]], 0
|
|
// CHECK-LPAD-NEXT: %[[val2:.+]] = insertvalue { ptr, i32 } %[[val1]], i32 %[[sel]], 1
|
|
// CHECK-LPAD-NEXT: resume { ptr, i32 } %[[val2]]
|