clang/test/CodeGenCoroutines/coro-await-domination.cpp

   1 // RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -std=c++20 -emit-llvm %s -o - | FileCheck %s
   2 #include "Inputs/coroutine.h"
   3
   4 using namespace std;
   5
   6 struct coro {
   7   struct promise_type {
   8     coro get_return_object();
   9     suspend_never initial_suspend();
  10     suspend_never final_suspend() noexcept;
  11     void return_void();
  12     static void unhandled_exception();
  13   };
  14 };
  15
  16 struct A {
  17   ~A();
  18   bool await_ready();
  19   int await_resume() { return 8; }
  20   template <typename F> void await_suspend(F);
  21 };
  22
  23 extern "C" void consume(int);
  24
  25 // Verifies that domination is properly built during cleanup.
  26 // Without CGCleanup.cpp fix verifier was reporting:
  27 // Instruction does not dominate all uses!
  28 //  %tmp.exprcleanup = alloca i32*, align 8
  29 //  store i32* %x, i32** %tmp.exprcleanup, align 8
  30
  31
  32 // CHECK-LABEL: f(
  33 extern "C" coro f(int) {
  34   int x = 42;
  35   x = co_await A{};
  36   consume(x);
  37 }