CMP0194 — CMake 4.2.6 Documentation

# CMP0194

Added in version 4.1.

MSVC is not an assembler for language ASM.

When enabling the `ASM` language, CMake considers C compiler drivers as assembler candidates. CMake 4.0 and below accidentally selected MSVC's `cl` compiler as the `CMAKE_ASM_COMPILER`, allowing the `ASM` language to be enabled on Windows even though `cl` does not support assembler sources. CMake 4.1 and above prefer to reject `cl` as an assembler candidate, but some existing projects unconditionally enable `ASM` on Windows even though they add no assembler sources. This policy provides compatibility for such projects to allow them to configure as before.

The `OLD` behavior for this policy is to successfully enable `ASM` even if `cl` is the only available candidate. The `NEW` behavior for this policy is to not consider `cl` as a candidate assembler for the `ASM` language.

This policy was introduced in CMake version 4.1. It may be set by `cmake_policy()` or `cmake_minimum_required()`. If it is not set, CMake warns, 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.