llvm-capstone/clang/test/CodeGenCoroutines/coro-unhandled-exception.cpp
Xun Li 516803dc86 [Coroutines] Ensure co_await promise.final_suspend() does not throw
Summary:
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.

Reviewers: lewissbaker, modocache, junparser

Reviewed By: modocache

Subscribers: arphaman, junparser, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D82029
2020-06-22 15:01:42 -07:00

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2.7 KiB
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// RUN: %clang_cc1 -std=c++14 -fcoroutines-ts -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++14 -fcoroutines-ts -triple=x86_64-unknown-linux-gnu -emit-llvm -o - %s -fexceptions -fcxx-exceptions -disable-llvm-passes | FileCheck --check-prefix=CHECK-LPAD %s
#include "Inputs/coroutine.h"
namespace coro = std::experimental::coroutines_v1;
namespace std {
using exception_ptr = int;
exception_ptr current_exception();
}
struct coro_t {
struct promise_type {
coro_t get_return_object() {
coro::coroutine_handle<promise_type>{};
return {};
}
coro::suspend_never initial_suspend() { return {}; }
coro::suspend_never final_suspend() noexcept { return {}; }
void return_void(){}
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 %{{.+}} unwind label %[[EHCLEANUP:.+]]
// CHECK: [[EHCLEANUP]]:
// CHECK: %[[INNERPAD:.+]] = cleanuppad within none []
// CHECK: call void @"??1Cleanup@@QEAA@XZ"(
// CHECK: cleanupret from %[[INNERPAD]] unwind label %[[CATCHSW:.+]]
// CHECK: [[CATCHSW]]:
// CHECK: %[[CATCHSWTOK:.+]] = catchswitch within none [label %[[CATCH:.+]]] unwind label
// CHECK: [[CATCH]]:
// CHECK: %[[CATCHTOK:.+]] = catchpad within [[CATCHSWTOK:.+]]
// CHECK: call void @"?unhandled_exception@promise_type@coro_t@@QEAAXXZ"
// CHECK: catchret from %[[CATCHTOK]] to label %[[CATCHRETDEST:.+]]
// CHECK: [[CATCHRETDEST]]:
// CHECK-NEXT: br label %[[TRYCONT:.+]]
// CHECK: [[TRYCONT]]:
// CHECK-NEXT: br label %[[COROFIN:.+]]
// CHECK: [[COROFIN]]:
// 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()
// CHECK-LPAD: to label %[[CONT:.+]] unwind label %[[CLEANUP:.+]]
// CHECK-LPAD: [[CLEANUP]]:
// CHECK-LPAD: call void @_ZN7CleanupD1Ev(%struct.Cleanup* %x) #2
// CHECK-LPAD: br label %[[CATCH:.+]]
// CHECK-LPAD: [[CATCH]]:
// CHECK-LPAD: call i8* @__cxa_begin_catch
// CHECK-LPAD: call void @_ZN6coro_t12promise_type19unhandled_exceptionEv(%"struct.coro_t::promise_type"* %__promise) #2
// CHECK-LPAD: invoke void @__cxa_end_catch()
// CHECK-LPAD-NEXT: to label %[[CATCHRETDEST:.+]] unwind label
// CHECK-LPAD: [[CATCHRETDEST]]:
// CHECK-LPAD-NEXT: br label %[[TRYCONT:.+]]
// CHECK-LPAD: [[TRYCONT]]:
// CHECK-LPAD: br label %[[COROFIN:.+]]
// CHECK-LPAD: [[COROFIN]]:
// CHECK-LPAD-NEXT: call void @_ZN6coro_t12promise_type13final_suspendEv(