CMP0204

Added in version 4.2.

A character set is always defined when targeting the MSVC ABI.

In CMake 4.1 and below, Visual Studio Generators compile sources in with _MBCS, _UNICODE or _SBCS defined due to behavior of Visual Studio itself. The preprocessor definition is not modeled by CMake and is therefore not added by other generators, such as Ninja.

CMake 4.2 and above, when targeting the MSVC ABI, prefer to compile sources with _MBCS defined by all generators unless another charset preprocessor definition is found (_UNICODE or _SBCS). This policy provides compatibility with projects that have not been updated to be aware of the definition. Its setting is recorded by each target as it is created, and affects compilation of sources in that target.

The OLD behavior for this policy does not model the _MBCS preprocessor definition in CMake itself. The NEW behavior for this policy adds the _MBCS preprocessor definition to sources as a default encoding when targeting the MSVC ABI.

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.