lxfind created this revision.
lxfind added reviewers: lewissbaker, modocache.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.
This patch addresses https://bugs.llvm.org/show_bug.cgi?id=46256
The spec of coroutine requires that the expression co_await
promise.final_suspend() shall not be potentially-throwing.
To check this, we recursively look at every call (including Call, MemberCall,
OperatorCall and Constructor) in all code
generated by the final suspend, and ensure that the callees are declared with
noexcept. We also look at any returned data
type that requires explicit destruction, and check their destructors for
noexcept.
This patch does not check declarations with dependent types yet, which will be
done in future patches.
Updated all tests to add noexcept to the required functions, and added a
dedicated test for this patch.
This patch might start to cause existing codebase fail to compile because most
people may not have been strict in tagging
all the related functions noexcept.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D82029
Files:
clang/include/clang/Basic/DiagnosticSemaKinds.td
clang/include/clang/Sema/Sema.h
clang/lib/Sema/SemaCoroutine.cpp
clang/lib/Sema/SemaExceptionSpec.cpp
clang/test/AST/Inputs/std-coroutine.h
clang/test/AST/coroutine-source-location-crash.cpp
clang/test/CodeGenCXX/ubsan-coroutines.cpp
clang/test/CodeGenCoroutines/Inputs/coroutine.h
clang/test/CodeGenCoroutines/coro-alloc.cpp
clang/test/CodeGenCoroutines/coro-always-inline.cpp
clang/test/CodeGenCoroutines/coro-await-domination.cpp
clang/test/CodeGenCoroutines/coro-await-resume-eh.cpp
clang/test/CodeGenCoroutines/coro-await.cpp
clang/test/CodeGenCoroutines/coro-dest-slot.cpp
clang/test/CodeGenCoroutines/coro-gro-nrvo.cpp
clang/test/CodeGenCoroutines/coro-newpm-pipeline.cpp
clang/test/CodeGenCoroutines/coro-params.cpp
clang/test/CodeGenCoroutines/coro-promise-dtor.cpp
clang/test/CodeGenCoroutines/coro-ret-void.cpp
clang/test/CodeGenCoroutines/coro-return-voidtype-initlist.cpp
clang/test/CodeGenCoroutines/coro-return.cpp
clang/test/CodeGenCoroutines/coro-unhandled-exception.cpp
clang/test/SemaCXX/Inputs/std-coroutine.h
clang/test/SemaCXX/coroutine-final-suspend-noexcept.cpp
clang/test/SemaCXX/coroutine-rvo.cpp
clang/test/SemaCXX/coroutine-unhandled_exception-warning.cpp
clang/test/SemaCXX/coroutine-uninitialized-warning-crash.cpp
clang/test/SemaCXX/coroutines.cpp
Index: clang/test/SemaCXX/coroutines.cpp
===================================================================
--- clang/test/SemaCXX/coroutines.cpp
+++ clang/test/SemaCXX/coroutines.cpp
@@ -52,21 +52,24 @@
};
struct awaitable {
- bool await_ready();
- template <typename F> void await_suspend(F);
- void await_resume();
+ bool await_ready() noexcept;
+ template <typename F>
+ void await_suspend(F) noexcept;
+ void await_resume() noexcept;
} a;
struct suspend_always {
- bool await_ready() { return false; }
- template <typename F> void await_suspend(F);
- void await_resume() {}
+ bool await_ready() noexcept { return false; }
+ template <typename F>
+ void await_suspend(F) noexcept;
+ void await_resume() noexcept {}
};
struct suspend_never {
- bool await_ready() { return true; }
- template <typename F> void await_suspend(F);
- void await_resume() {}
+ bool await_ready() noexcept { return true; }
+ template <typename F>
+ void await_suspend(F) noexcept;
+ void await_resume() noexcept {}
};
struct auto_await_suspend {
@@ -127,7 +130,7 @@
struct promise {
void get_return_object();
suspend_always initial_suspend();
- suspend_always final_suspend();
+ suspend_always final_suspend() noexcept;
awaitable yield_value(int); // expected-note 2{{candidate}}
awaitable yield_value(yielded_thing); // expected-note 2{{candidate}}
not_awaitable yield_value(void()); // expected-note 2{{candidate}}
@@ -138,7 +141,7 @@
struct promise_void {
void get_return_object();
suspend_always initial_suspend();
- suspend_always final_suspend();
+ suspend_always final_suspend() noexcept;
void return_void();
void unhandled_exception();
};
@@ -152,13 +155,13 @@
namespace experimental {
template <class PromiseType = void>
struct coroutine_handle {
- static coroutine_handle from_address(void *);
+ static coroutine_handle from_address(void *) noexcept;
};
template <>
struct coroutine_handle<void> {
template <class PromiseType>
- coroutine_handle(coroutine_handle<PromiseType>);
- static coroutine_handle from_address(void *);
+ coroutine_handle(coroutine_handle<PromiseType>) noexcept;
+ static coroutine_handle from_address(void *) noexcept;
};
}} // namespace std::experimental
@@ -402,7 +405,7 @@
namespace adl_ns {
struct coawait_arg_type {};
-awaitable operator co_await(coawait_arg_type);
+awaitable operator co_await(coawait_arg_type) noexcept;
}
namespace dependent_operator_co_await_lookup {
@@ -434,7 +437,7 @@
typedef transform_awaitable await_arg;
coro<transform_promise> get_return_object();
transformed initial_suspend();
- ::adl_ns::coawait_arg_type final_suspend();
+ ::adl_ns::coawait_arg_type final_suspend() noexcept;
transformed await_transform(transform_awaitable);
void unhandled_exception();
void return_void();
@@ -444,7 +447,7 @@
typedef AwaitArg await_arg;
coro<basic_promise> get_return_object();
awaitable initial_suspend();
- awaitable final_suspend();
+ awaitable final_suspend() noexcept;
void unhandled_exception();
void return_void();
};
@@ -527,7 +530,7 @@
void return_value(int());
suspend_never initial_suspend();
- suspend_never final_suspend();
+ suspend_never final_suspend() noexcept;
void get_return_object();
void unhandled_exception();
};
@@ -561,7 +564,7 @@
struct bad_promise_1 {
suspend_always initial_suspend();
- suspend_always final_suspend();
+ suspend_always final_suspend() noexcept;
void unhandled_exception();
void return_void();
};
@@ -571,7 +574,7 @@
struct bad_promise_2 {
coro<bad_promise_2> get_return_object();
- suspend_always final_suspend();
+ suspend_always final_suspend() noexcept;
void unhandled_exception();
void return_void();
};
@@ -586,14 +589,14 @@
void unhandled_exception();
void return_void();
};
-coro<bad_promise_3> missing_final_suspend() { // expected-error {{no member named 'final_suspend' in 'bad_promise_3'}}
+coro<bad_promise_3> missing_final_suspend() noexcept { // expected-error {{no member named 'final_suspend' in 'bad_promise_3'}}
co_await a;
}
struct bad_promise_4 {
coro<bad_promise_4> get_return_object();
not_awaitable initial_suspend();
- suspend_always final_suspend();
+ suspend_always final_suspend() noexcept;
void return_void();
};
// FIXME: This diagnostic is terrible.
@@ -605,7 +608,7 @@
struct bad_promise_5 {
coro<bad_promise_5> get_return_object();
suspend_always initial_suspend();
- not_awaitable final_suspend();
+ not_awaitable final_suspend() noexcept;
void return_void();
};
// FIXME: This diagnostic is terrible.
@@ -617,7 +620,7 @@
struct bad_promise_6 {
coro<bad_promise_6> get_return_object();
suspend_always initial_suspend();
- suspend_always final_suspend();
+ suspend_always final_suspend() noexcept;
void unhandled_exception();
void return_void(); // expected-note 2 {{member 'return_void' first declared here}}
void return_value(int) const; // expected-note 2 {{member 'return_value' first declared here}}
@@ -636,7 +639,7 @@
struct bad_promise_7 { // expected-note 2 {{defined here}}
coro<bad_promise_7> get_return_object();
suspend_always initial_suspend();
- suspend_always final_suspend();
+ suspend_always final_suspend() noexcept;
void return_void();
};
coro<bad_promise_7> no_unhandled_exception() { // expected-error {{'bad_promise_7' is required to declare the member 'unhandled_exception()'}}
@@ -656,7 +659,7 @@
struct bad_promise_8 : bad_promise_base {
coro<bad_promise_8> get_return_object();
suspend_always initial_suspend();
- suspend_always final_suspend();
+ suspend_always final_suspend() noexcept;
void unhandled_exception() __attribute__((unavailable)); // expected-note 2 {{marked unavailable here}}
void unhandled_exception() const;
void unhandled_exception(void *) const;
@@ -678,7 +681,7 @@
struct bad_promise_9 {
coro<bad_promise_9> get_return_object();
suspend_always initial_suspend();
- suspend_always final_suspend();
+ suspend_always final_suspend() noexcept;
void await_transform(void *);
awaitable await_transform(int) __attribute__((unavailable)); // expected-note {{explicitly marked unavailable}}
void return_void();
@@ -691,7 +694,7 @@
struct bad_promise_10 {
coro<bad_promise_10> get_return_object();
suspend_always initial_suspend();
- suspend_always final_suspend();
+ suspend_always final_suspend() noexcept;
int await_transform;
void return_void();
void unhandled_exception();
@@ -710,7 +713,7 @@
struct good_promise_1 {
coro<good_promise_1> get_return_object();
suspend_always initial_suspend();
- suspend_always final_suspend();
+ suspend_always final_suspend() noexcept;
void unhandled_exception();
static const call_operator await_transform;
using Fn = void (*)();
@@ -748,7 +751,7 @@
struct good_promise_2 {
float get_return_object();
suspend_always initial_suspend();
- suspend_always final_suspend();
+ suspend_always final_suspend() noexcept;
void return_void();
void unhandled_exception();
};
@@ -781,7 +784,7 @@
struct promise_type {
int get_return_object() {}
suspend_always initial_suspend() { return {}; }
- suspend_always final_suspend() { return {}; }
+ suspend_always final_suspend() noexcept { return {}; }
void return_void() {}
int get_return_object_on_allocation_failure(); // expected-error{{'promise_type': 'get_return_object_on_allocation_failure()' must be a static member function}}
void unhandled_exception();
@@ -795,7 +798,7 @@
struct bad_promise_11 {
coro<bad_promise_11> get_return_object();
suspend_always initial_suspend();
- suspend_always final_suspend();
+ suspend_always final_suspend() noexcept;
void unhandled_exception();
void return_void();
@@ -818,7 +821,7 @@
struct bad_promise_12 {
coro<bad_promise_12> get_return_object();
suspend_always initial_suspend();
- suspend_always final_suspend();
+ suspend_always final_suspend() noexcept;
void unhandled_exception();
void return_void();
static coro<bad_promise_12> get_return_object_on_allocation_failure();
@@ -840,7 +843,7 @@
struct good_promise_13 {
coro<good_promise_13> get_return_object();
suspend_always initial_suspend();
- suspend_always final_suspend();
+ suspend_always final_suspend() noexcept;
void unhandled_exception();
void return_void();
static coro<good_promise_13> get_return_object_on_allocation_failure();
@@ -858,7 +861,7 @@
struct good_promise_custom_new_operator {
coro<good_promise_custom_new_operator> get_return_object();
suspend_always initial_suspend();
- suspend_always final_suspend();
+ suspend_always final_suspend() noexcept;
void return_void();
void unhandled_exception();
void *operator new(SizeT, double, float, int);
@@ -874,7 +877,7 @@
struct good_promise_nonstatic_member_custom_new_operator {
coro<good_promise_nonstatic_member_custom_new_operator> get_return_object();
suspend_always initial_suspend();
- suspend_always final_suspend();
+ suspend_always final_suspend() noexcept;
void return_void();
void unhandled_exception();
void *operator new(SizeT, coroutine_nonstatic_member_struct &, double);
@@ -884,7 +887,7 @@
static coro<good_promise_noexcept_custom_new_operator> get_return_object_on_allocation_failure();
coro<good_promise_noexcept_custom_new_operator> get_return_object();
suspend_always initial_suspend();
- suspend_always final_suspend();
+ suspend_always final_suspend() noexcept;
void return_void();
void unhandled_exception();
void *operator new(SizeT, double, float, int) noexcept;
@@ -901,7 +904,7 @@
struct promise_type {
void get_return_object() {} //expected-note {{member 'get_return_object' declared here}}
suspend_always initial_suspend() { return {}; }
- suspend_always final_suspend() { return {}; }
+ suspend_always final_suspend() noexcept { return {}; }
void return_void() {}
void unhandled_exception();
};
@@ -918,7 +921,7 @@
struct promise_type {
void *get_return_object() {} //expected-note {{member 'get_return_object' declared here}}
suspend_always initial_suspend() { return {}; }
- suspend_always final_suspend() { return {}; }
+ suspend_always final_suspend() noexcept { return {}; }
void return_void() {}
void unhandled_exception();
};
@@ -936,7 +939,7 @@
int get_return_object() {}
static void get_return_object_on_allocation_failure() {} //expected-note {{member 'get_return_object_on_allocation_failure' declared here}}
suspend_always initial_suspend() { return {}; }
- suspend_always final_suspend() { return {}; }
+ suspend_always final_suspend() noexcept { return {}; }
void return_void() {}
void unhandled_exception();
};
@@ -955,7 +958,7 @@
int get_return_object() {}
static char *get_return_object_on_allocation_failure() {} //expected-note {{member 'get_return_object_on_allocation_failure' declared}}
suspend_always initial_suspend() { return {}; }
- suspend_always final_suspend() { return {}; }
+ suspend_always final_suspend() noexcept { return {}; }
void return_void() {}
void unhandled_exception();
};
@@ -969,7 +972,7 @@
struct bad_promise_no_return_func { // expected-note {{'bad_promise_no_return_func' defined here}}
coro<bad_promise_no_return_func> get_return_object();
suspend_always initial_suspend();
- suspend_always final_suspend();
+ suspend_always final_suspend() noexcept;
void unhandled_exception();
};
// FIXME: The PDTS currently specifies this as UB, technically forbidding a
@@ -1081,7 +1084,7 @@
CoroMemberTag get_return_object();
suspend_always initial_suspend();
- suspend_always final_suspend();
+ suspend_always final_suspend() noexcept;
AwaitTestT yield_value(int);
@@ -1290,7 +1293,7 @@
bad_promise_deleted_constructor() = delete;
coro<bad_promise_deleted_constructor> get_return_object();
suspend_always initial_suspend();
- suspend_always final_suspend();
+ suspend_always final_suspend() noexcept;
void return_void();
void unhandled_exception();
};
@@ -1312,7 +1315,7 @@
good_promise_default_constructor() = default;
coro<good_promise_default_constructor> get_return_object();
suspend_always initial_suspend();
- suspend_always final_suspend();
+ suspend_always final_suspend() noexcept;
void return_void();
void unhandled_exception();
};
@@ -1330,7 +1333,7 @@
good_promise_custom_constructor() = delete;
coro<good_promise_custom_constructor> get_return_object();
suspend_always initial_suspend();
- suspend_always final_suspend();
+ suspend_always final_suspend() noexcept;
void return_void();
void unhandled_exception();
};
@@ -1357,7 +1360,7 @@
bad_promise_no_matching_constructor() = delete;
coro<bad_promise_no_matching_constructor> get_return_object();
suspend_always initial_suspend();
- suspend_always final_suspend();
+ suspend_always final_suspend() noexcept;
void return_void();
void unhandled_exception();
};
@@ -1381,26 +1384,25 @@
class awaitable_no_unused_warn {
public:
using handle_type = std::experimental::coroutine_handle<>;
- constexpr bool await_ready() { return false; }
+ constexpr bool await_ready() noexcept { return false; }
void await_suspend(handle_type) noexcept {}
- int await_resume() { return 1; }
+ int await_resume() noexcept { return 1; }
};
class awaitable_unused_warn {
public:
using handle_type = std::experimental::coroutine_handle<>;
- constexpr bool await_ready() { return false; }
+ constexpr bool await_ready() noexcept { return false; }
void await_suspend(handle_type) noexcept {}
- [[nodiscard]]
- int await_resume() { return 1; }
+ [[nodiscard]] int await_resume() noexcept { return 1; }
};
template <class Await>
struct check_warning_promise {
coro<check_warning_promise> get_return_object();
Await initial_suspend();
- Await final_suspend();
+ Await final_suspend() noexcept;
Await yield_value(int);
void return_void();
void unhandled_exception();
Index: clang/test/SemaCXX/coroutine-uninitialized-warning-crash.cpp
===================================================================
--- clang/test/SemaCXX/coroutine-uninitialized-warning-crash.cpp
+++ clang/test/SemaCXX/coroutine-uninitialized-warning-crash.cpp
@@ -16,7 +16,7 @@
struct promise_type {
coro_t get_return_object() { return {}; }
suspend_never initial_suspend() { return {}; }
- suspend_never final_suspend() { return {}; }
+ suspend_never final_suspend() noexcept { return {}; }
A yield_value(int) { return {}; }
void return_void() {}
static void unhandled_exception() {}
Index: clang/test/SemaCXX/coroutine-unhandled_exception-warning.cpp
===================================================================
--- clang/test/SemaCXX/coroutine-unhandled_exception-warning.cpp
+++ clang/test/SemaCXX/coroutine-unhandled_exception-warning.cpp
@@ -23,7 +23,7 @@
#endif
void get_return_object();
suspend_always initial_suspend();
- suspend_always final_suspend();
+ suspend_always final_suspend() noexcept;
void return_void();
};
Index: clang/test/SemaCXX/coroutine-rvo.cpp
===================================================================
--- clang/test/SemaCXX/coroutine-rvo.cpp
+++ clang/test/SemaCXX/coroutine-rvo.cpp
@@ -49,7 +49,7 @@
struct task {
struct promise_type {
auto initial_suspend() { return suspend_never{}; }
- auto final_suspend() { return suspend_never{}; }
+ auto final_suspend() noexcept { return suspend_never{}; }
auto get_return_object() { return task{}; }
static void unhandled_exception() {}
void return_value(T&& value) {}
Index: clang/test/SemaCXX/coroutine-final-suspend-noexcept.cpp
===================================================================
--- /dev/null
+++ clang/test/SemaCXX/coroutine-final-suspend-noexcept.cpp
@@ -0,0 +1,62 @@
+// This file contains references to sections of the Coroutines TS, which can be
+// found at http://wg21.link/coroutines.
+
+// RUN: %clang_cc1 -std=c++14 -fcoroutines-ts -verify %s -fcxx-exceptions -fexceptions -Wunused-result
+
+namespace std {
+namespace experimental {
+
+template <class Ret, typename... T>
+struct coroutine_traits { using promise_type = typename Ret::promise_type; };
+
+template <class Promise = void>
+struct coroutine_handle {
+ static coroutine_handle from_address(void *); // expected-note {{must be declared with 'noexcept'}}
+};
+template <>
+struct coroutine_handle<void> {
+ template <class PromiseType>
+ coroutine_handle(coroutine_handle<PromiseType>); // expected-note {{must be declared with 'noexcept'}}
+};
+
+struct suspend_never {
+ bool await_ready() { return true; } // expected-note {{must be declared with 'noexcept'}}
+ void await_suspend(coroutine_handle<>) {} // expected-note {{must be declared with 'noexcept'}}
+ void await_resume() {} // expected-note {{must be declared with 'noexcept'}}
+ ~suspend_never() noexcept(false); // expected-note {{must be declared with 'noexcept'}}
+};
+
+struct suspend_always {
+ bool await_ready() { return false; }
+ void await_suspend(coroutine_handle<>) {}
+ void await_resume() {}
+ suspend_never operator co_await(); // expected-note {{must be declared with 'noexcept'}}
+ ~suspend_always() noexcept(false); // expected-note {{must be declared with 'noexcept'}}
+};
+
+} // namespace experimental
+} // namespace std
+
+using namespace std::experimental;
+
+struct A {
+ bool await_ready();
+ void await_resume();
+ template <typename F>
+ void await_suspend(F);
+};
+
+struct coro_t {
+ struct promise_type {
+ coro_t get_return_object();
+ suspend_never initial_suspend();
+ suspend_always final_suspend(); // expected-note {{must be declared with 'noexcept'}}
+ void return_void();
+ static void unhandled_exception();
+ };
+};
+
+coro_t f(int n) { // expected-error {{all code generated by co_await __promise.final_suspend() must not throw}}
+ A a{};
+ co_await a;
+}
Index: clang/test/SemaCXX/Inputs/std-coroutine.h
===================================================================
--- clang/test/SemaCXX/Inputs/std-coroutine.h
+++ clang/test/SemaCXX/Inputs/std-coroutine.h
@@ -10,25 +10,25 @@
template <class Promise = void>
struct coroutine_handle {
- static coroutine_handle from_address(void *);
+ static coroutine_handle from_address(void *) noexcept;
};
template <>
struct coroutine_handle<void> {
template <class PromiseType>
- coroutine_handle(coroutine_handle<PromiseType>);
+ coroutine_handle(coroutine_handle<PromiseType>) noexcept;
static coroutine_handle from_address(void *);
};
struct suspend_always {
- bool await_ready() { return false; }
- void await_suspend(coroutine_handle<>) {}
- void await_resume() {}
+ bool await_ready() noexcept { return false; }
+ void await_suspend(coroutine_handle<>) noexcept {}
+ void await_resume() noexcept {}
};
struct suspend_never {
- bool await_ready() { return true; }
- void await_suspend(coroutine_handle<>) {}
- void await_resume() {}
+ bool await_ready() noexcept { return true; }
+ void await_suspend(coroutine_handle<>) noexcept {}
+ void await_resume() noexcept {}
};
} // namespace experimental
Index: clang/test/CodeGenCoroutines/coro-unhandled-exception.cpp
===================================================================
--- clang/test/CodeGenCoroutines/coro-unhandled-exception.cpp
+++ clang/test/CodeGenCoroutines/coro-unhandled-exception.cpp
@@ -17,7 +17,7 @@
return {};
}
coro::suspend_never initial_suspend() { return {}; }
- coro::suspend_never final_suspend() { return {}; }
+ coro::suspend_never final_suspend() noexcept { return {}; }
void return_void(){}
void unhandled_exception() noexcept;
};
@@ -48,11 +48,9 @@
// CHECK: [[CATCHRETDEST]]:
// CHECK-NEXT: br label %[[TRYCONT:.+]]
// CHECK: [[TRYCONT]]:
-// CHECK-NEXT: br label %[[RESUMECONT:.+]]
-// CHECK: [[RESUMECONT]]:
// CHECK-NEXT: br label %[[COROFIN:.+]]
// CHECK: [[COROFIN]]:
-// CHECK-NEXT: invoke void @"?final_suspend@promise_type@coro_t@@QEAA?AUsuspend_never@coroutines_v1@experimental@std@@XZ"(
+// CHECK-NEXT: call void @"?final_suspend@promise_type@coro_t@@QEAA?AUsuspend_never@coroutines_v1@experimental@std@@XZ"(
// CHECK-LPAD: @_Z1fv(
// CHECK-LPAD: invoke void @_Z9may_throwv()
@@ -69,8 +67,6 @@
// CHECK-LPAD: [[CATCHRETDEST]]:
// CHECK-LPAD-NEXT: br label %[[TRYCONT:.+]]
// CHECK-LPAD: [[TRYCONT]]:
-// CHECK-LPAD: br label %[[RESUMECONT:.+]]
-// CHECK-LPAD: [[RESUMECONT]]:
-// CHECK-LPAD-NEXT: br label %[[COROFIN:.+]]
+// CHECK-LPAD: br label %[[COROFIN:.+]]
// CHECK-LPAD: [[COROFIN]]:
-// CHECK-LPAD-NEXT: invoke void @_ZN6coro_t12promise_type13final_suspendEv(
+// CHECK-LPAD-NEXT: call void @_ZN6coro_t12promise_type13final_suspendEv(
Index: clang/test/CodeGenCoroutines/coro-return.cpp
===================================================================
--- clang/test/CodeGenCoroutines/coro-return.cpp
+++ clang/test/CodeGenCoroutines/coro-return.cpp
@@ -5,27 +5,27 @@
template <class Promise = void> struct coroutine_handle {
coroutine_handle() = default;
- static coroutine_handle from_address(void *) { return {}; }
+ static coroutine_handle from_address(void *) noexcept { return {}; }
};
template <> struct coroutine_handle<void> {
static coroutine_handle from_address(void *) { return {}; }
coroutine_handle() = default;
template <class PromiseType>
- coroutine_handle(coroutine_handle<PromiseType>) {}
+ coroutine_handle(coroutine_handle<PromiseType>) noexcept {}
};
}
struct suspend_always {
- bool await_ready();
- void await_suspend(std::experimental::coroutine_handle<>);
- void await_resume();
+ bool await_ready() noexcept;
+ void await_suspend(std::experimental::coroutine_handle<>) noexcept;
+ void await_resume() noexcept;
};
template <> struct std::experimental::coroutine_traits<void> {
struct promise_type {
void get_return_object();
suspend_always initial_suspend();
- suspend_always final_suspend();
+ suspend_always final_suspend() noexcept;
void return_void();
};
};
@@ -44,7 +44,7 @@
struct promise_type {
int get_return_object();
suspend_always initial_suspend();
- suspend_always final_suspend();
+ suspend_always final_suspend() noexcept;
void return_value(int);
};
};
Index: clang/test/CodeGenCoroutines/coro-return-voidtype-initlist.cpp
===================================================================
--- clang/test/CodeGenCoroutines/coro-return-voidtype-initlist.cpp
+++ clang/test/CodeGenCoroutines/coro-return-voidtype-initlist.cpp
@@ -14,7 +14,7 @@
struct coroutine_handle<> {};
template <typename>
struct coroutine_handle : coroutine_handle<> {
- static coroutine_handle from_address(void *);
+ static coroutine_handle from_address(void *) noexcept;
};
struct e {
int await_ready();
@@ -29,13 +29,13 @@
struct f;
struct g {
struct h {
- int await_ready();
+ int await_ready() noexcept;
template <typename al>
- void await_suspend(std::experimental::coroutine_handle<al>);
- void await_resume();
+ void await_suspend(std::experimental::coroutine_handle<al>) noexcept;
+ void await_resume() noexcept;
};
std::experimental::e initial_suspend();
- h final_suspend();
+ h final_suspend() noexcept;
template <typename ag>
auto await_transform(ag) { return ah(ag()); }
};
Index: clang/test/CodeGenCoroutines/coro-ret-void.cpp
===================================================================
--- clang/test/CodeGenCoroutines/coro-ret-void.cpp
+++ clang/test/CodeGenCoroutines/coro-ret-void.cpp
@@ -8,7 +8,7 @@
struct promise_type {
coro1 get_return_object();
coro::suspend_never initial_suspend();
- coro::suspend_never final_suspend();
+ coro::suspend_never final_suspend() noexcept;
void return_void();
};
};
@@ -39,7 +39,7 @@
struct promise_type {
coro2 get_return_object();
coro::suspend_never initial_suspend();
- coro::suspend_never final_suspend();
+ coro::suspend_never final_suspend() noexcept;
void return_value(int);
};
};
Index: clang/test/CodeGenCoroutines/coro-promise-dtor.cpp
===================================================================
--- clang/test/CodeGenCoroutines/coro-promise-dtor.cpp
+++ clang/test/CodeGenCoroutines/coro-promise-dtor.cpp
@@ -11,7 +11,7 @@
struct promise_type {
coro_t get_return_object();
coro::suspend_never initial_suspend();
- coro::suspend_never final_suspend();
+ coro::suspend_never final_suspend() noexcept;
void return_void();
promise_type();
~promise_type();
Index: clang/test/CodeGenCoroutines/coro-params.cpp
===================================================================
--- clang/test/CodeGenCoroutines/coro-params.cpp
+++ clang/test/CodeGenCoroutines/coro-params.cpp
@@ -142,7 +142,7 @@
promise_type() = delete;
void get_return_object() {}
suspend_always initial_suspend() { return {}; }
- suspend_always final_suspend() { return {}; }
+ suspend_always final_suspend() noexcept { return {}; }
void return_void() {}
void unhandled_exception() {}
};
@@ -166,7 +166,7 @@
promise_type(some_class&, float);
method get_return_object();
suspend_always initial_suspend();
- suspend_always final_suspend();
+ suspend_always final_suspend() noexcept;
void return_void();
void unhandled_exception();
};
Index: clang/test/CodeGenCoroutines/coro-newpm-pipeline.cpp
===================================================================
--- clang/test/CodeGenCoroutines/coro-newpm-pipeline.cpp
+++ clang/test/CodeGenCoroutines/coro-newpm-pipeline.cpp
@@ -33,19 +33,19 @@
struct handle {};
struct awaitable {
- bool await_ready() { return true; }
- void await_suspend(handle) {}
- bool await_resume() { return true; }
+ bool await_ready() noexcept { return true; }
+ void await_suspend(handle) noexcept {}
+ bool await_resume() noexcept { return true; }
};
template <typename T> struct coroutine_handle {
- static handle from_address(void *address) { return {}; }
+ static handle from_address(void *address) noexcept { return {}; }
};
template <typename T = void> struct coroutine_traits {
struct promise_type {
awaitable initial_suspend() { return {}; }
- awaitable final_suspend() { return {}; }
+ awaitable final_suspend() noexcept { return {}; }
void return_void() {}
T get_return_object() { return T(); }
void unhandled_exception() {}
Index: clang/test/CodeGenCoroutines/coro-gro-nrvo.cpp
===================================================================
--- clang/test/CodeGenCoroutines/coro-gro-nrvo.cpp
+++ clang/test/CodeGenCoroutines/coro-gro-nrvo.cpp
@@ -21,7 +21,7 @@
struct promise_type {
RetObject get_return_object();
suspend_always initial_suspend();
- suspend_never final_suspend();
+ suspend_never final_suspend() noexcept;
void return_void();
static void unhandled_exception();
};
@@ -52,7 +52,7 @@
static RetObject get_return_object_on_allocation_failure();
RetObject get_return_object();
suspend_always initial_suspend();
- suspend_never final_suspend();
+ suspend_never final_suspend() noexcept;
void return_void();
static void unhandled_exception();
};
Index: clang/test/CodeGenCoroutines/coro-dest-slot.cpp
===================================================================
--- clang/test/CodeGenCoroutines/coro-dest-slot.cpp
+++ clang/test/CodeGenCoroutines/coro-dest-slot.cpp
@@ -8,7 +8,7 @@
struct promise_type {
coro get_return_object();
suspend_always initial_suspend();
- suspend_never final_suspend();
+ suspend_never final_suspend() noexcept;
void return_void();
static void unhandled_exception();
};
Index: clang/test/CodeGenCoroutines/coro-await.cpp
===================================================================
--- clang/test/CodeGenCoroutines/coro-await.cpp
+++ clang/test/CodeGenCoroutines/coro-await.cpp
@@ -17,7 +17,7 @@
template <typename Promise>
struct coroutine_handle : coroutine_handle<> {
- static coroutine_handle from_address(void *);
+ static coroutine_handle from_address(void *) noexcept;
};
}
@@ -29,9 +29,9 @@
void await_resume();
};
struct final_susp {
- bool await_ready();
- void await_suspend(std::experimental::coroutine_handle<>);
- void await_resume();
+ bool await_ready() noexcept;
+ void await_suspend(std::experimental::coroutine_handle<>) noexcept;
+ void await_resume() noexcept;
};
struct suspend_always {
@@ -46,7 +46,7 @@
struct promise_type {
void get_return_object();
init_susp initial_suspend();
- final_susp final_suspend();
+ final_susp final_suspend() noexcept;
void return_void();
};
};
@@ -119,7 +119,7 @@
struct promise_type {
void get_return_object();
init_susp initial_suspend();
- final_susp final_suspend();
+ final_susp final_suspend() noexcept;
void return_void();
suspend_maybe yield_value(int);
};
@@ -295,7 +295,7 @@
struct promise_type {
void get_return_object();
init_susp initial_suspend();
- final_susp final_suspend();
+ final_susp final_suspend() noexcept;
void return_void();
AwaitResumeReturnsLValue yield_value(int);
};
Index: clang/test/CodeGenCoroutines/coro-await-resume-eh.cpp
===================================================================
--- clang/test/CodeGenCoroutines/coro-await-resume-eh.cpp
+++ clang/test/CodeGenCoroutines/coro-await-resume-eh.cpp
@@ -22,7 +22,7 @@
struct promise_type {
auto get_return_object() { return throwing_task{}; }
auto initial_suspend() { return throwing_awaitable{}; }
- auto final_suspend() { return coro::suspend_never{}; }
+ auto final_suspend() noexcept { return coro::suspend_never{}; }
void return_void() {}
void unhandled_exception() {}
};
@@ -76,7 +76,7 @@
// CHECK-NEXT: br label %[[COROFINAL]]
// CHECK: [[COROFINAL]]:
- // CHECK-NEXT: invoke void @_ZN13throwing_task12promise_type13final_suspendEv
+ // CHECK-NEXT: call void @_ZN13throwing_task12promise_type13final_suspendEv
co_return;
}
@@ -90,7 +90,7 @@
struct promise_type {
auto get_return_object() { return noexcept_task{}; }
auto initial_suspend() { return noexcept_awaitable{}; }
- auto final_suspend() { return coro::suspend_never{}; }
+ auto final_suspend() noexcept { return coro::suspend_never{}; }
void return_void() {}
void unhandled_exception() {}
};
Index: clang/test/CodeGenCoroutines/coro-await-domination.cpp
===================================================================
--- clang/test/CodeGenCoroutines/coro-await-domination.cpp
+++ clang/test/CodeGenCoroutines/coro-await-domination.cpp
@@ -7,7 +7,7 @@
struct promise_type {
coro get_return_object();
suspend_never initial_suspend();
- suspend_never final_suspend();
+ suspend_never final_suspend() noexcept;
void return_void();
static void unhandled_exception();
};
@@ -35,4 +35,3 @@
x = co_await A{};
consume(x);
}
-
Index: clang/test/CodeGenCoroutines/coro-always-inline.cpp
===================================================================
--- clang/test/CodeGenCoroutines/coro-always-inline.cpp
+++ clang/test/CodeGenCoroutines/coro-always-inline.cpp
@@ -14,22 +14,22 @@
struct handle {};
struct awaitable {
- bool await_ready() { return true; }
+ bool await_ready() noexcept { return true; }
// CHECK-NOT: await_suspend
- inline void __attribute__((__always_inline__)) await_suspend(handle) {}
- bool await_resume() { return true; }
+ inline void __attribute__((__always_inline__)) await_suspend(handle) noexcept {}
+ bool await_resume() noexcept { return true; }
};
template <typename T>
struct coroutine_handle {
- static handle from_address(void *address) { return {}; }
+ static handle from_address(void *address) noexcept { return {}; }
};
template <typename T = void>
struct coroutine_traits {
struct promise_type {
awaitable initial_suspend() { return {}; }
- awaitable final_suspend() { return {}; }
+ awaitable final_suspend() noexcept { return {}; }
void return_void() {}
T get_return_object() { return T(); }
void unhandled_exception() {}
Index: clang/test/CodeGenCoroutines/coro-alloc.cpp
===================================================================
--- clang/test/CodeGenCoroutines/coro-alloc.cpp
+++ clang/test/CodeGenCoroutines/coro-alloc.cpp
@@ -10,7 +10,7 @@
template <class Promise = void>
struct coroutine_handle {
coroutine_handle() = default;
- static coroutine_handle from_address(void *) { return {}; }
+ static coroutine_handle from_address(void *) noexcept { return {}; }
};
template <>
@@ -18,7 +18,7 @@
static coroutine_handle from_address(void *) { return {}; }
coroutine_handle() = default;
template <class PromiseType>
- coroutine_handle(coroutine_handle<PromiseType>) {}
+ coroutine_handle(coroutine_handle<PromiseType>) noexcept {}
};
} // end namespace experimental
@@ -36,9 +36,9 @@
struct suspend_always {
- bool await_ready() { return false; }
- void await_suspend(std::experimental::coroutine_handle<>) {}
- void await_resume() {}
+ bool await_ready() noexcept { return false; }
+ void await_suspend(std::experimental::coroutine_handle<>) noexcept {}
+ void await_resume() noexcept {}
};
struct global_new_delete_tag {};
@@ -48,7 +48,7 @@
struct promise_type {
void get_return_object() {}
suspend_always initial_suspend() { return {}; }
- suspend_always final_suspend() { return {}; }
+ suspend_always final_suspend() noexcept { return {}; }
void return_void() {}
};
};
@@ -89,7 +89,7 @@
void *operator new(unsigned long);
void get_return_object() {}
suspend_always initial_suspend() { return {}; }
- suspend_always final_suspend() { return {}; }
+ suspend_always final_suspend() noexcept { return {}; }
void return_void() {}
};
};
@@ -115,7 +115,7 @@
int, float, double);
void get_return_object() {}
suspend_always initial_suspend() { return {}; }
- suspend_always final_suspend() { return {}; }
+ suspend_always final_suspend() noexcept { return {}; }
void return_void() {}
};
};
@@ -145,7 +145,7 @@
struct promise_type {
void get_return_object() {}
suspend_always initial_suspend() { return {}; }
- suspend_always final_suspend() { return {}; }
+ suspend_always final_suspend() noexcept { return {}; }
void return_void() {}
};
};
@@ -168,7 +168,7 @@
void operator delete(void*);
void get_return_object() {}
suspend_always initial_suspend() { return {}; }
- suspend_always final_suspend() { return {}; }
+ suspend_always final_suspend() noexcept { return {}; }
void return_void() {}
};
};
@@ -193,7 +193,7 @@
void operator delete(void*, unsigned long);
void get_return_object() {}
suspend_always initial_suspend() { return {}; }
- suspend_always final_suspend() { return {}; }
+ suspend_always final_suspend() noexcept { return {}; }
void return_void() {}
};
};
@@ -218,7 +218,7 @@
struct promise_type {
int get_return_object() { return 0; }
suspend_always initial_suspend() { return {}; }
- suspend_always final_suspend() { return {}; }
+ suspend_always final_suspend() noexcept { return {}; }
void return_void() {}
static int get_return_object_on_allocation_failure() { return -1; }
};
Index: clang/test/CodeGenCoroutines/Inputs/coroutine.h
===================================================================
--- clang/test/CodeGenCoroutines/Inputs/coroutine.h
+++ clang/test/CodeGenCoroutines/Inputs/coroutine.h
@@ -72,9 +72,9 @@
void await_resume() {}
};
struct suspend_never {
- bool await_ready() { return true; }
- void await_suspend(coroutine_handle<>) {}
- void await_resume() {}
+ bool await_ready() noexcept { return true; }
+ void await_suspend(coroutine_handle<>) noexcept {}
+ void await_resume() noexcept {}
};
}}}
Index: clang/test/CodeGenCXX/ubsan-coroutines.cpp
===================================================================
--- clang/test/CodeGenCXX/ubsan-coroutines.cpp
+++ clang/test/CodeGenCXX/ubsan-coroutines.cpp
@@ -32,7 +32,7 @@
struct promise_type {
task get_return_object() { return task(); }
suspend_always initial_suspend() { return {}; }
- suspend_always final_suspend() { return {}; }
+ suspend_always final_suspend() noexcept { return {}; }
void return_void() {}
void unhandled_exception() {}
};
Index: clang/test/AST/coroutine-source-location-crash.cpp
===================================================================
--- clang/test/AST/coroutine-source-location-crash.cpp
+++ clang/test/AST/coroutine-source-location-crash.cpp
@@ -15,7 +15,7 @@
struct promise_type {
coro_t get_return_object();
suspend_never initial_suspend();
- suspend_never final_suspend();
+ suspend_never final_suspend() noexcept;
void return_void();
static void unhandled_exception();
};
Index: clang/test/AST/Inputs/std-coroutine.h
===================================================================
--- clang/test/AST/Inputs/std-coroutine.h
+++ clang/test/AST/Inputs/std-coroutine.h
@@ -10,12 +10,12 @@
template <class Promise = void>
struct coroutine_handle {
- static coroutine_handle from_address(void *);
+ static coroutine_handle from_address(void *) noexcept;
};
template <>
struct coroutine_handle<void> {
template <class PromiseType>
- coroutine_handle(coroutine_handle<PromiseType>);
+ coroutine_handle(coroutine_handle<PromiseType>) noexcept;
static coroutine_handle from_address(void *);
};
@@ -26,9 +26,9 @@
};
struct suspend_never {
- bool await_ready() { return true; }
- void await_suspend(coroutine_handle<>) {}
- void await_resume() {}
+ bool await_ready() noexcept { return true; }
+ void await_suspend(coroutine_handle<>) noexcept {}
+ void await_resume() noexcept {}
};
} // namespace experimental
Index: clang/lib/Sema/SemaExceptionSpec.cpp
===================================================================
--- clang/lib/Sema/SemaExceptionSpec.cpp
+++ clang/lib/Sema/SemaExceptionSpec.cpp
@@ -999,10 +999,8 @@
return R;
}
-/// Determine whether the callee of a particular function call can throw.
-/// E and D are both optional, but at least one of E and Loc must be specified.
-static CanThrowResult canCalleeThrow(Sema &S, const Expr *E, const Decl *D,
- SourceLocation Loc = SourceLocation()) {
+CanThrowResult Sema::canCalleeThrow(Sema &S, const Expr *E, const Decl *D,
+ SourceLocation Loc) {
// As an extension, we assume that __attribute__((nothrow)) functions don't
// throw.
if (D && isa<FunctionDecl>(D) && D->hasAttr<NoThrowAttr>())
@@ -1048,7 +1046,9 @@
if (!FT)
return CT_Can;
- FT = S.ResolveExceptionSpec(Loc.isInvalid() ? E->getBeginLoc() : Loc, FT);
+ if (Loc.isValid() || (Loc.isInvalid() && E)) {
+ FT = S.ResolveExceptionSpec(Loc.isInvalid() ? E->getBeginLoc() : Loc, FT);
+ }
if (!FT)
return CT_Can;
@@ -1069,7 +1069,7 @@
VD->getType()->getBaseElementTypeUnsafe()->getAsCXXRecordDecl()) {
if (auto *Dtor = RD->getDestructor()) {
CT = mergeCanThrow(
- CT, canCalleeThrow(Self, nullptr, Dtor, VD->getLocation()));
+ CT, Sema::canCalleeThrow(Self, nullptr, Dtor, VD->getLocation()));
}
}
}
Index: clang/lib/Sema/SemaCoroutine.cpp
===================================================================
--- clang/lib/Sema/SemaCoroutine.cpp
+++ clang/lib/Sema/SemaCoroutine.cpp
@@ -24,6 +24,7 @@
#include "clang/Sema/Overload.h"
#include "clang/Sema/ScopeInfo.h"
#include "clang/Sema/SemaInternal.h"
+#include "llvm/ADT/SmallSet.h"
using namespace clang;
using namespace sema;
@@ -604,6 +605,66 @@
return ScopeInfo;
}
+/// Recursively check \p E and all its children to see if any call target
+/// (including constructor call) is declared noexcept. Also any value returned
+/// from the call has a noexcept destructor.
+static void checkNoThrow(Sema &S, const Stmt *E,
+ llvm::SmallPtrSetImpl<const Decl *> &ThrowingDecls) {
+ auto checkDeclNoexcept = [&](const Decl *D, bool IsDtor = false) {
+ // In the case of dtor, the call to dtor is implicit and hence we should
+ // pass nullptr to canCalleeThrow.
+ if (Sema::canCalleeThrow(S, IsDtor ? nullptr : cast<Expr>(E), D)) {
+ if (ThrowingDecls.empty()) {
+ // First time seeing an error, emit the error message.
+ S.Diag(cast<FunctionDecl>(S.CurContext)->getLocation(),
+ diag::err_coroutine_promise_final_suspend_requires_nothrow);
+ }
+ ThrowingDecls.insert(D);
+ }
+ };
+ auto SC = E->getStmtClass();
+ if (SC == Expr::CXXConstructExprClass) {
+ auto const *Ctor = cast<CXXConstructExpr>(E)->getConstructor();
+ checkDeclNoexcept(Ctor);
+ // Check the corresponding destructor of the constructor.
+ checkDeclNoexcept(Ctor->getParent()->getDestructor(), true);
+ } else if (SC == Expr::CallExprClass || SC == Expr::CXXMemberCallExprClass ||
+ SC == Expr::CXXOperatorCallExprClass) {
+ if (!cast<CallExpr>(E)->isTypeDependent()) {
+ // FIXME: Handle dependent types.
+ checkDeclNoexcept(cast<CallExpr>(E)->getCalleeDecl());
+ auto ReturnType = cast<CallExpr>(E)->getCallReturnType(S.getASTContext());
+ // Check the destructor of the call return type, if any.
+ if (ReturnType.isDestructedType() ==
+ QualType::DestructionKind::DK_cxx_destructor) {
+ const auto *T =
+ cast<RecordType>(ReturnType.getCanonicalType().getTypePtr());
+ checkDeclNoexcept(
+ dyn_cast<CXXRecordDecl>(T->getDecl())->getDestructor(), true);
+ }
+ }
+ }
+ for (const auto *Child : E->children()) {
+ if (!Child)
+ continue;
+ checkNoThrow(S, Child, ThrowingDecls);
+ }
+}
+
+/// Check that the expression co_await promise.final_suspend() shall not be
+/// potentially-throwing.
+static bool checkNoThrow(Sema &S, const Stmt *FinalSuspend) {
+ llvm::SmallPtrSet<const Decl *, 4> ThrowingDecls;
+ // We first collect all declarations that should not throw but not declared
+ // with noexcept. This is to avoid emitting the same note multiple times
+ // on the same declaration.
+ checkNoThrow(S, FinalSuspend, ThrowingDecls);
+ for (const auto *D : ThrowingDecls) {
+ S.Diag(D->getEndLoc(), diag::note_coroutine_function_declare_noexcept);
+ }
+ return ThrowingDecls.empty();
+}
+
bool Sema::ActOnCoroutineBodyStart(Scope *SC, SourceLocation KWLoc,
StringRef Keyword) {
if (!checkCoroutineContext(*this, KWLoc, Keyword))
@@ -646,7 +707,7 @@
return false;
StmtResult FinalSuspend = buildSuspends("final_suspend");
- if (FinalSuspend.isInvalid())
+ if (FinalSuspend.isInvalid() || !checkNoThrow(*this, FinalSuspend.get()))
return false;
ScopeInfo->setCoroutineSuspends(InitSuspend.get(), FinalSuspend.get());
Index: clang/include/clang/Sema/Sema.h
===================================================================
--- clang/include/clang/Sema/Sema.h
+++ clang/include/clang/Sema/Sema.h
@@ -1697,6 +1697,11 @@
static QualType GetTypeFromParser(ParsedType Ty,
TypeSourceInfo **TInfo = nullptr);
CanThrowResult canThrow(const Stmt *E);
+ /// Determine whether the callee of a particular function call can throw.
+ /// E and D are both optional, but at least one of E and Loc must be
+ /// specified.
+ static CanThrowResult canCalleeThrow(Sema &S, const Expr *E, const Decl *D,
+ SourceLocation Loc = SourceLocation());
const FunctionProtoType *ResolveExceptionSpec(SourceLocation Loc,
const FunctionProtoType *FPT);
void UpdateExceptionSpec(FunctionDecl *FD,
Index: clang/include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -10517,7 +10517,13 @@
def note_await_ready_no_bool_conversion : Note<
"return type of 'await_ready' is required to be contextually convertible to 'bool'"
>;
-}
+def err_coroutine_promise_final_suspend_requires_nothrow : Error<
+ "all code generated by co_await __promise.final_suspend() must not throw"
+>;
+def note_coroutine_function_declare_noexcept : Note<
+ "must be declared with 'noexcept'"
+>;
+} // end of coroutines issue category
let CategoryName = "Documentation Issue" in {
def warn_not_a_doxygen_trailing_member_comment : Warning<
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