| 1 | // Test the behavior of http://wg21.link/P0664, a proposal to catch any |
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| 2 | // exceptions thrown after the initial suspend point of a coroutine by |
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| 3 | // executing the handler specified by the promise type's 'unhandled_exception' |
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| 4 | // member function. |
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| 5 | // |
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| 6 | // RUN: %clang_cc1 -std=c++14 -fcoroutines-ts \ |
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| 7 | // RUN: -triple=x86_64-unknown-linux-gnu -emit-llvm -o - %s \ |
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| 8 | // RUN: -fexceptions -fcxx-exceptions -disable-llvm-passes \ |
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| 9 | // RUN: | FileCheck %s |
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| 10 | |
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| 11 | #include "Inputs/coroutine.h" |
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| 12 | |
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| 13 | namespace coro = std::experimental::coroutines_v1; |
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| 14 | |
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| 15 | struct throwing_awaitable { |
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| 16 | bool await_ready() { return true; } |
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| 17 | void await_suspend(coro::coroutine_handle<>) {} |
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| 18 | void await_resume() { throw 42; } |
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| 19 | }; |
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| 20 | |
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| 21 | struct throwing_task { |
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| 22 | struct promise_type { |
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| 23 | auto get_return_object() { return throwing_task{}; } |
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| 24 | auto initial_suspend() { return throwing_awaitable{}; } |
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| 25 | auto final_suspend() { return coro::suspend_never{}; } |
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| 26 | void return_void() {} |
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| 27 | void unhandled_exception() {} |
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| 28 | }; |
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| 29 | }; |
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| 30 | |
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| 31 | // CHECK-LABEL: define void @_Z1fv() |
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| 32 | throwing_task f() { |
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| 33 | // A variable RESUMETHREW is used to keep track of whether the body |
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| 34 | // of 'await_resume' threw an exception. Exceptions thrown in |
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| 35 | // 'await_resume' are unwound to RESUMELPAD. |
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| 36 | // CHECK: init.ready: |
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| 37 | // CHECK-NEXT: store i1 true, i1* %[[RESUMETHREW:.+]], align 1 |
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| 38 | // CHECK-NEXT: invoke void @_ZN18throwing_awaitable12await_resumeEv |
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| 39 | // CHECK-NEXT: to label %[[RESUMECONT:.+]] unwind label %[[RESUMELPAD:.+]] |
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| 40 | |
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| 41 | // If 'await_resume' does not throw an exception, 'false' is stored in |
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| 42 | // variable RESUMETHREW. |
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| 43 | // CHECK: [[RESUMECONT]]: |
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| 44 | // CHECK-NEXT: store i1 false, i1* %[[RESUMETHREW]] |
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| 45 | // CHECK-NEXT: br label %[[RESUMETRYCONT:.+]] |
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| 46 | |
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| 47 | // 'unhandled_exception' is called for the exception thrown in |
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| 48 | // 'await_resume'. The variable RESUMETHREW is never set to false, |
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| 49 | // and a jump is made to RESUMETRYCONT. |
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| 50 | // CHECK: [[RESUMELPAD]]: |
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| 51 | // CHECK: br label %[[RESUMECATCH:.+]] |
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| 52 | // CHECK: [[RESUMECATCH]]: |
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| 53 | // CHECK: invoke void @_ZN13throwing_task12promise_type19unhandled_exceptionEv |
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| 54 | // CHECK-NEXT: to label %[[RESUMEENDCATCH:.+]] unwind label |
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| 55 | // CHECK: [[RESUMEENDCATCH]]: |
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| 56 | // CHECK-NEXT: invoke void @__cxa_end_catch() |
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| 57 | // CHECK-NEXT: to label %[[RESUMEENDCATCHCONT:.+]] unwind label |
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| 58 | // CHECK: [[RESUMEENDCATCHCONT]]: |
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| 59 | // CHECK-NEXT: br label %[[RESUMETRYCONT]] |
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| 60 | |
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| 61 | // The variable RESUMETHREW is loaded and if true, then 'await_resume' |
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| 62 | // threw an exception and the coroutine body is skipped, and the final |
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| 63 | // suspend is executed immediately. Otherwise, the coroutine body is |
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| 64 | // executed, and then the final suspend. |
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| 65 | // CHECK: [[RESUMETRYCONT]]: |
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| 66 | // CHECK-NEXT: %[[RESUMETHREWLOAD:.+]] = load i1, i1* %[[RESUMETHREW]] |
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| 67 | // CHECK-NEXT: br i1 %[[RESUMETHREWLOAD]], label %[[RESUMEDCONT:.+]], label %[[RESUMEDBODY:.+]] |
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| 68 | |
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| 69 | // CHECK: [[RESUMEDBODY]]: |
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| 70 | // CHECK: invoke void @_ZN13throwing_task12promise_type11return_voidEv |
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| 71 | // CHECK-NEXT: to label %[[REDUMEDBODYCONT:.+]] unwind label |
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| 72 | // CHECK: [[REDUMEDBODYCONT]]: |
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| 73 | // CHECK-NEXT: br label %[[COROFINAL:.+]] |
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| 74 | |
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| 75 | // CHECK: [[RESUMEDCONT]]: |
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| 76 | // CHECK-NEXT: br label %[[COROFINAL]] |
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| 77 | |
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| 78 | // CHECK: [[COROFINAL]]: |
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| 79 | // CHECK-NEXT: invoke void @_ZN13throwing_task12promise_type13final_suspendEv |
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| 80 | co_return; |
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| 81 | } |
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| 82 | |
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| 83 | struct noexcept_awaitable { |
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| 84 | bool await_ready() { return true; } |
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| 85 | void await_suspend(coro::coroutine_handle<>) {} |
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| 86 | void await_resume() noexcept {} |
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| 87 | }; |
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| 88 | |
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| 89 | struct noexcept_task { |
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| 90 | struct promise_type { |
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| 91 | auto get_return_object() { return noexcept_task{}; } |
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| 92 | auto initial_suspend() { return noexcept_awaitable{}; } |
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| 93 | auto final_suspend() { return coro::suspend_never{}; } |
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| 94 | void return_void() {} |
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| 95 | void unhandled_exception() {} |
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| 96 | }; |
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| 97 | }; |
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| 98 | |
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| 99 | // CHECK-LABEL: define void @_Z1gv() |
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| 100 | noexcept_task g() { |
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| 101 | // If the await_resume function is marked as noexcept, none of the additional |
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| 102 | // conditions that are present in f() above are added to the IR. |
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| 103 | // This means that no i1 are stored before or after calling await_resume: |
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| 104 | // CHECK: init.ready: |
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| 105 | // CHECK-NEXT: call void @_ZN18noexcept_awaitable12await_resumeEv |
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| 106 | // CHECK-NOT: store i1 false, i1* |
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| 107 | co_return; |
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| 108 | } |
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| 109 | |
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