include(CheckCXXSourceCompiles) set (atomic_test_sources "#include #include void test(volatile std::atomic &a) { std::int64_t v = a.load(std::memory_order_acquire); while (!a.compare_exchange_strong(v, v + 1, std::memory_order_acq_rel, std::memory_order_acquire)) { v = a.exchange(v - 1); } a.store(v + 1, std::memory_order_release); } int main(int, char **) { void *ptr = (void*)0xffffffc0; // any random pointer test(*reinterpret_cast *>(ptr)); return 0; }") check_cxx_source_compiles("${atomic_test_sources}" HAVE_STDATOMIC) if(NOT HAVE_STDATOMIC) set(_req_libraries "${CMAKE_REQUIRE_LIBRARIES}") set(CMAKE_REQUIRE_LIBRARIES "atomic") check_cxx_source_compiles("${atomic_test_sources}" HAVE_STDATOMIC_WITH_LIB) set(CMAKE_REQUIRE_LIBRARIES "${_req_libraries}") endif() add_library(Atomic INTERFACE) if(HAVE_STDATOMIC_WITH_LIB) target_link_libraries(Atomic INTERFACE atomic) endif() set(Atomic_FOUND 1)