[cmake-developers] [Patch] Adding Windows 10 support

[Brad King]

On 08/30/2015 06:41 PM, Gilles Khouzam wrote:
> http://www.cmake.org/Bug/view.php?id=15670
> Add support for setting "Windows target platform version" in VS2015

Most of your changes look good but I think this issue needs more
discussion.  There is already some discussion in the issue tracker
entry linked above.

Your patch checks a VS_DEFAULT_TARGET_PLATFORM_VERSION variable
but does not document it or explain who/what is supposed to set
it.  There is a comment about using the latest SDK but right now
it looks like the value of that variable is used directly.

Having a VS_TARGET_PLATFORM_VERSION target property is convenient
for customization but should not be the main way to set this value.
The WindowsTargetPlatformVersion value is something that should
be set in try_compile projects too for consistency.  If we were
only cross-compiling then having a toolchain file setting would
make sense.  However, this should work when not cross-compiling
too.

On OS X we have CMAKE_OSX_SYSROOT to specify the SDK.  The value is
propagated by Source/cmCoreTryCompile.cxx into try_compile projects.
It is selected originally by Modules/Platform/Darwin-Initialize.cmake
if not specified by the user.  I think similar infrastructure should
be built for selecting the Windows SDK.

> As part of this change, I’m also fixing a bug when using VS2015 to
> target Windows Phone or Windows Store 8.1 without having VS2013
[snip]
> simply to make the desktop detection code be virtual.

Please split the relevant hunks for that part out so they can be
committed with their own message/explanation.

Thanks,
-Brad