113 lines · cpp
1// Test the behavior of http://wg21.link/P0664, a proposal to catch any2// exceptions thrown after the initial suspend point of a coroutine by3// executing the handler specified by the promise type's 'unhandled_exception'4// member function.5//6// RUN: %clang_cc1 -std=c++20 \7// RUN: -triple=x86_64-unknown-linux-gnu -emit-llvm -o - %s \8// RUN: -fexceptions -fcxx-exceptions -disable-llvm-passes \9// RUN: | FileCheck %s10 11#include "Inputs/coroutine.h"12 13struct throwing_awaitable {14 bool await_ready() { return true; }15 void await_suspend(std::coroutine_handle<>) {}16 void await_resume() { throw 42; }17};18 19struct throwing_task {20 struct promise_type {21 auto get_return_object() { return throwing_task{}; }22 auto initial_suspend() { return throwing_awaitable{}; }23 auto final_suspend() noexcept { return std::suspend_never{}; }24 void return_void() {}25 void unhandled_exception() {}26 };27};28 29// CHECK-LABEL: define{{.*}} void @_Z1fv()30throwing_task f() {31 // A variable RESUMETHREW is used to keep track of whether the body32 // of 'await_resume' threw an exception. Exceptions thrown in33 // 'await_resume' are unwound to RESUMELPAD.34 // CHECK: init.ready:35 // CHECK-NEXT: store i1 true, ptr %[[RESUMETHREW:.+]], align 136 // CHECK-NEXT: invoke void @_ZN18throwing_awaitable12await_resumeEv37 // CHECK-NEXT: to label %[[RESUMECONT:.+]] unwind label %[[RESUMELPAD:.+]]38 39 // If 'await_resume' does not throw an exception, 'false' is stored in40 // variable RESUMETHREW.41 // CHECK: [[RESUMECONT]]:42 // CHECK-NEXT: store i1 false, ptr %[[RESUMETHREW]]43 // CHECK-NEXT: br label %[[RESUMETRYCONT:.+]]44 45 // 'unhandled_exception' is called for the exception thrown in46 // 'await_resume'. The variable RESUMETHREW is never set to false,47 // and a jump is made to RESUMETRYCONT.48 // CHECK: [[RESUMELPAD]]:49 // CHECK: br label %[[RESUMECATCH:.+]]50 // CHECK: [[RESUMECATCH]]:51 // CHECK: invoke void @_ZN13throwing_task12promise_type19unhandled_exceptionEv52 // CHECK-NEXT: to label %[[RESUMEENDCATCH:.+]] unwind label53 // CHECK: [[RESUMEENDCATCH]]:54 // CHECK-NEXT: invoke void @__cxa_end_catch()55 // CHECK-NEXT: to label %[[RESUMEENDCATCHCONT:.+]] unwind label56 // CHECK: [[RESUMEENDCATCHCONT]]:57 // CHECK-NEXT: br label %[[RESUMETRYCONT]]58 // CHECK: [[RESUMETRYCONT]]:59 // CHECK-NEXT: br label %[[CLEANUP:.+]]60 // CHECK: [[CLEANUP]]:61 // CHECK: switch i32 %{{.+}}, label %{{.+}} [62 // CHECK-NEXT: i32 0, label %[[CLEANUPCONT:.+]]63 // CHECK-NEXT: ]64 65 // The variable RESUMETHREW is loaded and if true, then 'await_resume'66 // threw an exception and the coroutine body is skipped, and the final67 // suspend is executed immediately. Otherwise, the coroutine body is68 // executed, and then the final suspend.69 // CHECK: [[CLEANUPCONT]]:70 // CHECK-NEXT: %[[RESUMETHREWLOAD:.+]] = load i1, ptr %[[RESUMETHREW]]71 // CHECK-NEXT: br i1 %[[RESUMETHREWLOAD]], label %[[RESUMEDCONT:.+]], label %[[RESUMEDBODY:.+]]72 73 // CHECK: [[RESUMEDBODY]]:74 // CHECK: invoke void @_ZN13throwing_task12promise_type11return_voidEv75 // CHECK-NEXT: to label %[[REDUMEDBODYCONT:.+]] unwind label76 // CHECK: [[REDUMEDBODYCONT]]:77 // CHECK-NEXT: br label %[[COROFINAL:.+]]78 79 // CHECK: [[RESUMEDCONT]]:80 // CHECK-NEXT: br label %[[COROFINAL]]81 82 // CHECK: [[COROFINAL]]:83 // CHECK: call void @_ZN13throwing_task12promise_type13final_suspendEv84 co_return;85}86 87struct noexcept_awaitable {88 bool await_ready() { return true; }89 void await_suspend(std::coroutine_handle<>) {}90 void await_resume() noexcept {}91};92 93struct noexcept_task {94 struct promise_type {95 auto get_return_object() { return noexcept_task{}; }96 auto initial_suspend() { return noexcept_awaitable{}; }97 auto final_suspend() noexcept { return std::suspend_never{}; }98 void return_void() {}99 void unhandled_exception() {}100 };101};102 103// CHECK-LABEL: define{{.*}} void @_Z1gv()104noexcept_task g() {105 // If the await_resume function is marked as noexcept, none of the additional106 // conditions that are present in f() above are added to the IR.107 // This means that no i1 are stored before or after calling await_resume:108 // CHECK: init.ready:109 // CHECK-NEXT: call void @_ZN18noexcept_awaitable12await_resumeEv110 // CHECK-NOT: store i1 false, ptr111 co_return;112}113