Instead of CL_DEVICE_EXTENSIONS in Querying OpenCLVersion, it should be CL_DEVICE_VERSION flag which needs to be passed to the function.
{ return p ? p->getStrProp(CL_DEVICE_OPENCL_C_VERSION) : String(); }
String Device::OpenCLVersion() const
-{ return p ? p->getStrProp(CL_DEVICE_EXTENSIONS) : String(); }
+{ return p ? p->getStrProp(CL_DEVICE_VERSION) : String(); }
int Device::deviceVersionMajor() const
{ return p ? p->deviceVersionMajor_ : 0; }