# CMP0198

Added in version 4.2.

`CMAKE_PARENT_LIST_FILE` is not defined in `CMakeLists.txt`.

CMake 4.1 and below defined `CMAKE_PARENT_LIST_FILE` when processing a `CMakeLists.txt` even though there is no parent file. CMake 4.2 and above prefer to not define `CMAKE_PARENT_LIST_FILE`. This policy provides compatibility for projects that accidentally relied on the old behavior.

The `OLD` behavior for this policy is to set `CMAKE_PARENT_LIST_FILE` to `CMAKE_CURRENT_LIST_FILE` when processing a `CMakeLists.txt`. The `NEW` behavior for this policy is to not set `CMAKE_PARENT_LIST_FILE`.

This policy was introduced in CMake version 4.2. It may be set by `cmake_policy()` or `cmake_minimum_required()`. If it is not set, CMake does not warn, and uses `OLD` behavior.

Note

The `OLD` behavior of a policy is `deprecated by definition` and may be removed in a future version of CMake.