qt5base-lts/cmake/FindWrapRt.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 WrapRt::WrapRt)
    set(WrapRt_FOUND ON)
    return()
endif()

set(WrapRt_FOUND OFF)

include(CheckCXXSourceCompiles)
include(CMakePushCheckState)

find_library(LIBRT rt)

cmake_push_check_state()
if(LIBRT_FOUND)
    list(APPEND CMAKE_REQUIRED_LIBRARIES "${LIBRT}")
endif()

check_cxx_source_compiles("
#include <unistd.h>
#include <time.h>

int main(int argc, char *argv[]) {
    timespec ts; clock_gettime(CLOCK_REALTIME, &ts);
}" HAVE_GETTIME)

cmake_pop_check_state()


if(HAVE_GETTIME)
    set(WrapRt_FOUND ON)
    add_library(WrapRt::WrapRt INTERFACE IMPORTED)
    if (LIBRT_FOUND)
        target_link_libraries(WrapRt::WrapRt INTERFACE "${LIBRT}")
    endif()
endif()