a73baf620b
This fixes #69219. Consider an example: ``` CoTask my_coroutine() { std::abort(); co_return 1; // unreachable code warning. } ``` Clang emits a CFG-based unreachable warning on the `co_return` statement (precisely the `1` subexpr). If we remove this statement, the program semantic is changed (my_coroutine is not a coroutine anymore). This patch fixes this issue by never considering coroutine statements as dead statements.
77 lines
1.5 KiB
C++
77 lines
1.5 KiB
C++
// RUN: %clang_cc1 -triple x86_64-unknown-unknown %s -std=c++20 -fsyntax-only -verify -Wunreachable-code
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#include "Inputs/std-coroutine.h"
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extern void abort(void) __attribute__((__noreturn__));
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struct task {
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struct promise_type {
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std::suspend_always initial_suspend();
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std::suspend_always final_suspend() noexcept;
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void return_void();
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std::suspend_always yield_value(int) { return {}; }
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task get_return_object();
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void unhandled_exception();
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struct Awaiter {
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bool await_ready();
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void await_suspend(auto);
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int await_resume();
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};
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auto await_transform(const int& x) { return Awaiter{}; }
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};
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};
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task test1() {
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abort();
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co_yield 1;
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}
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task test2() {
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abort();
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1; // expected-warning {{code will never be executed}}
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co_yield 1;
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}
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task test3() {
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abort();
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co_return;
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}
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task test4() {
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abort();
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1; // expected-warning {{code will never be executed}}
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co_return;
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}
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task test5() {
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abort();
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co_await 1;
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}
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task test6() {
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abort();
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1; // expected-warning {{code will never be executed}}
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co_await 3;
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}
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task test7() {
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// coroutine statements are not considered unreachable.
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co_await 1;
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abort();
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co_await 2;
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}
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task test8() {
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// coroutine statements are not considered unreachable.
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abort();
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co_return;
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1 + 1; // expected-warning {{code will never be executed}}
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}
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task test9() {
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abort();
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// This warning is emitted on the declaration itself, rather the coroutine substmt.
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int x = co_await 1; // expected-warning {{code will never be executed}}
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}
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