--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libcxx/utils/google-benchmark/test/diagnostics_test.cc	Thu Feb 13 15:10:13 2020 +0900
@@ -0,0 +1,80 @@
+// Testing:
+//   State::PauseTiming()
+//   State::ResumeTiming()
+// Test that CHECK's within these function diagnose when they are called
+// outside of the KeepRunning() loop.
+//
+// NOTE: Users should NOT include or use src/check.h. This is only done in
+// order to test library internals.
+
+#include <cstdlib>
+#include <stdexcept>
+
+#include "../src/check.h"
+#include "benchmark/benchmark.h"
+
+#if defined(__GNUC__) && !defined(__EXCEPTIONS)
+#define TEST_HAS_NO_EXCEPTIONS
+#endif
+
+void TestHandler() {
+#ifndef TEST_HAS_NO_EXCEPTIONS
+  throw std::logic_error("");
+#else
+  std::abort();
+#endif
+}
+
+void try_invalid_pause_resume(benchmark::State& state) {
+#if !defined(TEST_BENCHMARK_LIBRARY_HAS_NO_ASSERTIONS) && !defined(TEST_HAS_NO_EXCEPTIONS)
+  try {
+    state.PauseTiming();
+    std::abort();
+  } catch (std::logic_error const&) {
+  }
+  try {
+    state.ResumeTiming();
+    std::abort();
+  } catch (std::logic_error const&) {
+  }
+#else
+  (void)state;  // avoid unused warning
+#endif
+}
+
+void BM_diagnostic_test(benchmark::State& state) {
+  static bool called_once = false;
+
+  if (called_once == false) try_invalid_pause_resume(state);
+
+  for (auto _ : state) {
+    benchmark::DoNotOptimize(state.iterations());
+  }
+
+  if (called_once == false) try_invalid_pause_resume(state);
+
+  called_once = true;
+}
+BENCHMARK(BM_diagnostic_test);
+
+
+void BM_diagnostic_test_keep_running(benchmark::State& state) {
+  static bool called_once = false;
+
+  if (called_once == false) try_invalid_pause_resume(state);
+
+  while(state.KeepRunning()) {
+    benchmark::DoNotOptimize(state.iterations());
+  }
+
+  if (called_once == false) try_invalid_pause_resume(state);
+
+  called_once = true;
+}
+BENCHMARK(BM_diagnostic_test_keep_running);
+
+int main(int argc, char* argv[]) {
+  benchmark::internal::GetAbortHandler() = &TestHandler;
+  benchmark::Initialize(&argc, argv);
+  benchmark::RunSpecifiedBenchmarks();
+}