The value of `CMAKE_VS_PLATFORM_NAME` is computed by Visual Studio
generators based on `CMAKE_GENERATOR_PLATFORM` or some default.
Prior to the VS 2019 generator, the default was always `Win32`.
However, for the `Visual Studio 16 2019` generator, the default is
based on the host platform.
Store the default in a new `CMAKE_VS_PLATFORM_NAME_DEFAULT` variable for
use by project code. This is particularly useful in toolchain files
because they are allowed to set `CMAKE_GENERATOR_PLATFORM` and so
`CMAKE_VS_PLATFORM_NAME` is not yet known. Of course the toolchain file
author knows whether it will set `CMAKE_GENERATOR_PLATFORM`, and if not
then `CMAKE_VS_PLATFORM_NAME_DEFAULT` provides the platform name that
will be used.
Fixes: #19177
CMake Tests Directory
*********************
This directory contains the CMake test suite.
See also the `CMake Source Code Guide`_.
.. _`CMake Source Code Guide`: ../Help/dev/source.rst
Many tests exist as immediate subdirectories, but some tests
are organized as follows.
* ``CMakeLib/``:
Source code, used for tests, that links to the ``CMakeLib`` library
defined over in ``Source/``.
* ``CMakeOnly/``:
Deprecated. Tests that run CMake to generate a project but not build it.
Superseded by ``Tests/RunCMake/``.
* ``Find*/``:
Tests for specific find modules that can only be run on machines with
the corresponding packages installed. They are enabled in
``CMakeLists.txt`` by undocumented options used on CI builds.
* ``Module/``:
Tests for specific CMake modules.
* ``RunCMake/``:
Tests that run CMake and/or other tools while precisely checking
their return code and stdout/stderr content. Useful for testing
error cases and diagnostic output.