CMP0218

Added in version 4.4.

The CMAKE_WARN_DEPRECATED and CMAKE_ERROR_DEPRECATED variables are ignored.

In CMake 4.3 and below, these variables controlled whether deprecation messages resulted in warnings, errors, or were suppressed. However, not all deprecation messages considered the non-cache values.

CMake 4.4 introduced a new, unified system for managing diagnostics that prefers the cmake_diagnostic() command for manipulating diagnostic actions.

This policy provides compatibility with projects that relied on these variables and have not been updated to be aware of the change.

The OLD behavior for this policy is to use the variables to control deprecation messages which respected the non-cache values of these variables in CMake 4.3 and earlier.

The NEW behavior does not ascribe any special meaning to the non-cache values of these variables and uses the CMD_DEPRECATED diagnostic state to control all deprecation messages.

Note

The CMAKE_WARN_DEPRECATED and CMAKE_ERROR_DEPRECATED cache variables are synchronized with the initial state of the CMD_DEPRECATED diagnostic, regardless of this policy's setting. (The synchronization happens at a point prior to when it is possible to manipulate policies.) However, this behavior is deprecated and will be removed in a future version of CMake.

Any deprecation messages introduced in CMake 4.4 or later are controlled by the CMD_DEPRECATED diagnostic regardless of the setting of this policy.

This policy was introduced in CMake version 4.4. It may be set by cmake_policy() or cmake_minimum_required(). If it is not set, CMake warns when either variable is accessed or modified, 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.