[EXPERIMENTAL] Add support for vcpkg

[stevapple]

Windows developers have a relatively difficult experience for pulling in dependencies. This patch adds support for vcpkg's manifest mode, which can seamlessly integrate with CMake.

[stevapple]

@tomerd This one is not WIP👀 The only thing we should do is to add such a manifest.

And it just automatically works.

[stevapple]

Anyone to merge?

[neonichu]

What exactly does this do and how is it used?

[stevapple]

@neonichu This adds a manifest file of vcpkg, allowing us to have:

-DCMAKE_TOOLCHAIN_FILE=[vcpkg-root]/scripts/buildsystems/vcpkg.cmake

flag passed on CMake, to let vcpkg provide the CMake packages for us, without having to install them in the system.

vcpkg will build everything from source and cache the artifacts across builds.

[compnerd]

The official builds and documentation don't install them on the system, they build them as part of the toolchain.

[tomerd]

@compnerd confused on how this relates to the toolchain build machinery already in place. should discuss this some more with @shahmishal and team?

[stevapple]

The official builds and documentation don't install them on the system, they build them as part of the toolchain.

I don’t think that’s the case for SQLite3 here. We’re never building SQLite along with the toolchain.

[compnerd]

I don’t think that’s the case for SQLite3 here. We’re never building SQLite along with the toolchain.

We actually do build SQLite3 from source as well.
https://github.com/apple/swift/blob/main/utils/build-windows-toolchain.bat#L56-L68

[stevapple]

I don’t think that’s the case for SQLite3 here. We’re never building SQLite along with the toolchain.

We actually do build SQLite3 from source as well. https://github.com/apple/swift/blob/main/utils/build-windows-toolchain.bat#L56-L68

vcpkg support is not meant for production now. It is used to ease anyone who wants to build and test their own copy.
Official build can continue to use manually built artifacts, as long as you don’t import vcpkg to CMake.

[compnerd]

vcpkg support is not meant for production now. It is used to ease anyone who wants to build and test their own copy. Official build can continue to use manually built artifacts, as long as you don’t import vcpkg to CMake.

Sure, but then does it make sense to perhaps have this be residing elsewhere?

[stevapple]

@compnerd I believe we’d better place it within our repo to keep it tracked if the dependencies change. Alternatively, we can pull in another repo containing only vcpkg manifests. Since vcpkg support will be documented, it’s not ideal for me to provide it with any non-apple repository.