Original behaviour would unconditionally enable WinRT for all projects
so source file flag generation code can acknowledge WinRT being present
and disable it for C language source files. An unintentional result of
that approach is that WinRT is enabled for ALL projects, including C++
projects/source files with no way to disable it
Instead use `CMAKE_VS_WINRT_BY_DEFAULT` as a hint that the platform is
WinRT-by-default and set global `CompileAsWinRT` flag to `false` unless
it was explicitly requested by either `WINRT_COMPONENT` option or `/ZW`
compilation option - similar to what Windows Phone/Windows Store
platform logic does
In case WinRT compilation is enabled for a project by either of
aforementioned methods, C language source file override logic will still
kick in and disable CompileAsWinRT for C source files
Fixes: #20063
Generator expressions in target property VS_CONFIGURATION_TYPE might be used to
set the ConfigurationType to Utility for certain configurations to not build
the target while still linking to the target in other configurations.
Fixes: #19613
The mapping for this flag was added by commit 43aa632f57 (VS: Populate
`-Qspectre-` flag table entry for v142, 2019-01-24, v3.14.0-rc1~74^2~7).
However, it did not do anything because the special logic added by
commit bb60ed6e72 (VS: Add flag table entry for -Qspectre, 2018-10-08,
v3.13.0-rc1~4^2) to move the `SpectreMitigation` element from
`ClCompile` to the top level only handled the presence of the setting
and not its value. Extend the special logic to carry the value too.
Fixes: #19535
Extend tests added by commit fb3370b6a1 (MSVC: Add abstraction for
runtime library selection, 2019-04-10) to cover an empty value for
the property. It should result in no specific setting.
Issue: #19108
Replace our hard-coded defaults for `/MD` and `/MDd` with a first-class
abstraction to select the runtime library from an enumeration of logical
names. We've long hesitated to do this because the idea of "runtime
library selection" touches on related concepts on several platforms.
Avoid that scope creep by simply defining an abstraction that applies
only when targeting the MSVC ABI on Windows.
Removing the old default flags requires a policy because existing
projects may rely on string processing to edit them and choose a runtime
library under the old behavior. Add policy CMP0091 to provide
compatibility.
Fixes: #19108
Since commit v3.11.0-rc1~467^2 (VS,Xcode: Add CMakeLists.txt sources
without mutating targets, 2017-10-18) we do not add `CMakeLists.txt` to
target sources but instead generate references to them directly. This
accidentally dropped generation of the `.vcxproj.filters` entry for a
source group in which `CMakeLists.txt` is the only member.
Fixes: #18795
Create `CMAKE_VS_SDK_*_DIRECTORIES` variables to tell the VS generator
how to populate fields in `.vcxproj` files that specify SDK directories.
Fixes: #17908
Since commit v3.11.0-rc1~467^2 (VS,Xcode: Add CMakeLists.txt sources
without mutating targets, 2017-10-18) we do not add `CMakeLists.txt` to
target sources but instead generate references to them directly. This
broke projects that explicitly specify their `CMakeLists.txt` file as a
source file because the explicit entry is no longer consolidated with
the generated one.
Teach the relevant generators to avoid duplicating `CMakeLists.txt`
source references and add test cases.
Fixes: #17828
