# CMP0038

Warning

The `OLD` behavior of this policy was removed in CMake version 4.0. This policy must be set to `NEW` by a call to `cmake_minimum_required()` or `cmake_policy()`.

Targets may not link directly to themselves.

CMake 2.8.12 and lower allowed a build target to link to itself directly with a `target_link_libraries()` call. This is an indicator of a bug in user code.

The `OLD` behavior for this policy is to ignore targets which list themselves in their own link implementation. The `NEW` behavior for this policy is to report an error if a target attempts to link to itself.

This policy was introduced in CMake version 3.0. 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.