| CMAKE_SYSTEM_VERSION |
| -------------------- |
| |
| The version of the operating system for which CMake is to build. |
| See the :variable:`CMAKE_SYSTEM_NAME` variable for the OS name. |
| |
| System Version for Host Builds |
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ |
| |
| When the :variable:`CMAKE_SYSTEM_NAME` variable takes its default value |
| then ``CMAKE_SYSTEM_VERSION`` is by default set to the same value as the |
| :variable:`CMAKE_HOST_SYSTEM_VERSION` variable so that the build targets |
| the host system version. |
| |
| In the case of a host build then ``CMAKE_SYSTEM_VERSION`` may be set |
| explicitly when first configuring a new build tree in order to enable |
| targeting the build for a different version of the host operating system |
| than is actually running on the host. This is allowed and not considered |
| cross compiling so long as the binaries built for the specified OS version |
| can still run on the host. |
| |
| System Version for Cross Compiling |
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ |
| |
| When the :variable:`CMAKE_SYSTEM_NAME` variable is set explicitly to |
| enable :ref:`cross compiling <Cross Compiling Toolchain>` then the |
| value of ``CMAKE_SYSTEM_VERSION`` must also be set explicitly to specify |
| the target system version. |
