[clang] [coroutine] Suppress unreachable-code warning on coroutine statements. (PR #77454)

[Utkarsh Saxena via cfe-commits]

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@@ -0,0 +1,65 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown %s -std=c++20 -fsyntax-only -verify -Wunreachable-code
+
+#include "Inputs/std-coroutine.h"
+
+extern void abort (void) __attribute__ ((__noreturn__));
+
+struct task {
+  struct promise_type {
+    std::suspend_always initial_suspend();
+    std::suspend_always final_suspend() noexcept;
+    void return_void();
+    std::suspend_always yield_value(int) { return {}; }
+    task get_return_object();
+    void unhandled_exception();
+  };
+};
+
+task test1() {
+  abort();
+  co_yield 1;
+}
+
+task test2() {
+  abort();
+  1; // expected-warning {{code will never be executed}}
+  co_yield 1;
+}
+
+task test3() {
+  abort();
+  co_return;
+}
+
+task test4() {
+  abort();
+  1; // expected-warning {{code will never be executed}}
+  co_return;
+}
+
+
+task test5() {
+  abort();
+  co_await std::suspend_never{};
+}
+
+task test6() {
+  abort();
+  1; // expected-warning {{code will never be executed}}
+  co_await std::suspend_never{};
+}
+
+task test7() {
+  // coroutine statements are not considered unreachable.
+  co_await std::suspend_never{};
+  abort();
+  co_await std::suspend_never{};
+}
+
+task test8() {
+  // coroutine statements are not considered unreachable.
+  // co_await std::suspend_never{};
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usx95 wrote:

nit: Delete comment.

https://github.com/llvm/llvm-project/pull/77454