CMP0059

Do not treat DEFINITIONS as a built-in directory property.

CMake 3.3 and above no longer make a list of definitions available through the DEFINITIONS directory property. The COMPILE_DEFINITIONS directory property may be used instead.

The OLD behavior for this policy is to provide the list of flags given so far to the add_definitions() command. The NEW behavior is to behave as a normal user-defined directory property.

This policy was introduced in CMake version 3.3. Prior to removal in CMake version 4.0, it could be set by cmake_policy() or cmake_minimum_required(). If it was not set, CMake warned, and used OLD behavior.