qt5base-lts/cmake/FindAtomic.cmake
Alexandru Croitor ace5495870 Fix a few of the Wrap modules to protect against double creation of
targets. This created issues when trying to build standalone examples.

Change-Id: Iaaea2b537793ae25fbf3143cc205574446aa4ad1
Reviewed-by: Kevin Funk <kevin.funk@kdab.com>
2019-06-05 12:30:47 +00:00

45 lines
1.3 KiB
CMake

# We can't create the same interface imported target multiple times, CMake will complain if we do
# that. This can happen if the find_package call is done in multiple different subdirectories.
if(TARGET Atomic)
set(Atomic_FOUND ON)
return()
endif()
include(CheckCXXSourceCompiles)
set (atomic_test_sources "#include <atomic>
#include <cstdint>
void test(volatile std::atomic<std::int64_t> &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<std::atomic<std::int64_t> *>(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 IMPORTED)
if(HAVE_STDATOMIC_WITH_LIB)
target_link_libraries(Atomic INTERFACE atomic)
endif()
set(Atomic_FOUND 1)