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
Add this generator *without* support for specifying the target
architecture in the generator name. cmake-gui will be taught
to provide a field for this, and command-line builds can use -A.
Also, teach this generator to select a default target architecture
based on the host architecture.
Fixes: #18689
Inspired-by: Egor Pugin <egor.pugin@gmail.com>
Call the generator "Visual Studio 15" without any year because the
preview version of VS 15 does not provide a year in the product name.
Copy cmGlobalVisualStudio14Generator to cmGlobalVisualStudio15Generator
and update version numbers accordingly. Add the VS15 enumeration value.
Note that we do not need to add a MSVC15 variable or v150 toolset
because Visual Studio 15 comes with an updated version of the v140
toolset and remains ABI-compatible.
Teach tests VSExternalInclude, RunCMake.GeneratorPlatform, and
RunCMake.GeneratorToolset to treat VS 15 as they do VS 10-14.
Closes: #16143
Define the 'cmake -A' option to set CMAKE_GENERATOR_PLATFORM
without having to spell out the whole variable name. We choose
the name '-A' for "platform" because '-P' is already taken, and
in the common use case the "platform" is actually an architecture
(e.g. x64).
Teach the RunCMake test infrastructure to use -A to pass the generator
platform. Extend the RunCMake.GeneratorPlatform test with a case to
verify that the -A option cannot be repeated.
For VS generator names that do not specify the platform name, read
CMAKE_GENERATOR_PLATFORM to get it.
Extend the RunCMake.GeneratorPlatform test with a case covering
use of the x64 platform when the test generator is a Visual Studio
generator whose name does not specify a platform.
Reject the option by default. It will be implemented on a per-generator
basis. Pass the setting into try_compile project generation. Add cache
entry CMAKE_GENERATOR_PLATFORM and associated variable documentation to
hold the value persistently.
Add a RunCMake.GeneratorPlatform test to cover basic use cases for the
option. Verify that CMAKE_GENERATOR_PLATFORM is empty by default, and
that it is rejected when the generator does not support a user setting.
