Merge topic 'remove-documentation-module'

306a1ba960 Modules/Documentation: remove
ad4487a96a cmIncludeCommand: add infrastructure for deprecated modules

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !4617

Help/manual/cmake-policies.7.rst

@@ -57,6 +57,7 @@ Policies Introduced by CMake 3.18
 .. toctree::
    :maxdepth: 1
 
+   CMP0106: The Documentation module is removed. </policy/CMP0106>
    CMP0105: Device link step uses the link options. </policy/CMP0105>
    CMP0104: CMAKE_CUDA_ARCHITECTURES now detected for NVCC, empty CUDA_ARCHITECTURES not allowed. </policy/CMP0104>
    CMP0103: Multiple export() with same FILE without APPEND is not allowed. </policy/CMP0103>

Help/policy/CMP0106.rst

@@ -0,0 +1,19 @@
+CMP0106
+-------
+
+The :module:`Documentation` module is removed.
+
+The :module:`Documentation` was added as a support mechanism for the VTK
+project and was tuned for that project. Instead of CMake providing this module
+with (now old) VTK patterns for cache variables and required packages, the
+module is now deprecated by CMake itself.
+
+The ``OLD`` behavior of this policy is for :module:`Documentation` to add
+cache variables and find VTK documentation dependent packages. The ``NEW``
+behavior is to act as an empty module.
+
+This policy was introduced in CMake version 3.18.  CMake version |release|
+warns when the policy is not set and uses ``OLD`` behavior. Use the
+:command:`cmake_policy` command to set it to ``OLD`` or ``NEW`` explicitly.
+
+.. include:: DEPRECATED.txt

Help/release/dev/deprecate-documentation-module.rst

@@ -0,0 +1,6 @@
+deprecate-documentation-module
+------------------------------
+
+* The :module:`Documentation` module has been deprecated via
+  :policy:`CMP0106`. This module was essentially VTK code that CMake should
+  not be shipping anymore.