# CMAKE_APPLE_SILICON_PROCESSOR

Added in version 3.19.2.

On Apple Silicon hosts running macOS, set this variable to tell CMake what architecture to use for `CMAKE_HOST_SYSTEM_PROCESSOR`. The value must be either `arm64` or `x86_64`.

The value of this variable should never be modified by project code. It is meant to be set as a cache entry provided by the user, e.g. via `-DCMAKE_APPLE_SILICON_PROCESSOR=...`.

See also the `CMAKE_APPLE_SILICON_PROCESSOR` environment variable.