Test for hardware support for atomics, link to libatomic if not detected

Author: barracuda156

CMakeLists.txt

@@ -25,12 +25,16 @@ message(STATUS "CMAKE_BUILD_TYPE is set to '${CMAKE_BUILD_TYPE}'")
 
 find_package(Threads REQUIRED)
 
+if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+  include(cmake/atomic.cmake)
+endif()
+
 # ------ Declare library ------
 
 add_library(libfork_libfork INTERFACE)
 add_library(libfork::libfork ALIAS libfork_libfork)
 
-target_link_libraries(libfork_libfork INTERFACE Threads::Threads)
+target_link_libraries(libfork_libfork INTERFACE Threads::Threads ${LIBFORK_EXTRA_LIBS})
 
 set_property(TARGET libfork_libfork PROPERTY EXPORT_NAME libfork)
 

cmake/atomic.cmake

@@ -0,0 +1,11 @@
+include(CheckCXXSourceCompiles)
+check_cxx_source_compiles("#include <atomic>
+int main() {
+  std::atomic<uint8_t> w1;
+  std::atomic<uint64_t> w8;
+  return ++w1 + ++w8;
+}" NATIVE_ATOMICS_SUPPORTED)
+
+if(NOT NATIVE_ATOMICS_SUPPORTED)
+  set(LIBFORK_EXTRA_LIBS ${LIBFORK_EXTRA_LIBS} atomic)
+endif()