gbe_fork/cmake/share/cmake-3.27/Help/policy/CMP0149.rst

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CMP0149
-------
.. versionadded:: 3.27
:ref:`Visual Studio Generators` select latest Windows SDK by default.
Visual Studio Generators select a Windows SDK version to put in the
``WindowsTargetPlatformVersion`` setting in ``.vcxproj`` files.
CMake sets the :variable:`CMAKE_VS_WINDOWS_TARGET_PLATFORM_VERSION`
variable to the selected SDK version.
Prior to CMake 3.27, the SDK version was always selected by the value of
the :variable:`CMAKE_SYSTEM_VERSION` variable. Users or toolchain files
could set that variable to one of the exact Windows SDK versions available
on the host system. Since :variable:`CMAKE_SYSTEM_VERSION` defaults to
:variable:`CMAKE_HOST_SYSTEM_VERSION`, and it is not guaranteed that a
matching Windows SDK version is available, CMake had to fall back to
using the latest Windows SDK version if no exact match was available.
This approach was problematic:
* The latest Windows SDK might or might not be selected based on whether
the host version of Windows happens to match an available SDK version.
* An old Windows SDK version might be selected that has not been updated
for newer language standards such as C11.
CMake 3.27 and higher prefer to ignore the exact value of
:variable:`CMAKE_SYSTEM_VERSION` and by default select the latest SDK
version available. An exact SDK version may be specified explicitly
using a ``version=`` field in the :variable:`CMAKE_GENERATOR_PLATFORM`
variable. See :ref:`Visual Studio Platform Selection`.
This policy provides compatibility for projects, toolchain files, and
build scripts that have not been ported away from using
:variable:`CMAKE_SYSTEM_VERSION` to specify an exact SDK version.
The ``OLD`` behavior for this policy is to use the exact value of
:variable:`CMAKE_SYSTEM_VERSION` if possible. The ``NEW`` behavior
for this policy is to ignore it.
This policy was introduced in CMake version 3.27. Use the
:command:`cmake_policy` command to set it to ``OLD`` or ``NEW`` explicitly.
Unlike many policies, CMake version |release| does *not* warn
when this policy is not set and simply uses ``OLD`` behavior.
.. include:: DEPRECATED.txt