[SR-1756] Implement SE-0069 Foundation Value Types for Linux

[colemancda]

Previous ID	SR-1756
Radar	None
Original Reporter	@colemancda
Type	Task
Status	Closed
Resolution	Done

Additional Detail from JIRA

Votes	0
Component/s	Foundation
Labels	Task
Assignee	@colemancda
Priority	Medium

md5: b443e427e2a021adcf3fd47521379381

Issue Description:

I would like to start the process of implementing SE-0069 for Linux.

Date, Data and UUID would be the first targets.

I previously did this in https://github.com/PureSwift/SwiftFoundation but now since the Swift Team has accepted this behavior, I want to get to work to make that available for all Swift users.

[belkadan]

I believe @phausler already has some of this ready to go, using the Darwin implementation. Philippe?

[colemancda]

@belkadan If that is the case, its useless on Linux because `ReferenceConvertible` is not gonna be present on the Linux platform. Today I'm gonna try to adapt the code in https://github.com/apple/swift/blob/d68c6dcd6b4be19cff9f6e82e2811884de56b6fa/stdlib/public/SDK/Foundation/UUID.swift

To Linux, without reference convertible, and not backed by CoreFoundation.

[belkadan]

Sorry, when I said "using the Darwin implementation" I meant "based on the Darwin implementation".

Please coordinate with Philippe either way. We don't want to duplicate work!

[colemancda]

@belkadan @phausler Of course, I'm ready to work on this today. Please tell me how I can help and what is already done so we can get this to Linux users ASAP. Data, Date, UUID are simple and I've implemented them before so those would be starters. But really the work is done in the Swift Darwin Foundation overlay, so its just a matter of making some Linux-specific changes, and removing the ObjC bridging.

[phausler]

https://github.com/apple/swift-corelibs-foundation/tree/swift-3 already has the value types on linux, this branch will be merged soon to master

[phausler]

And ReferenceConvertible is on linux, it just cannot adopt _ObjectiveCBridgeable since that does not exist. However there is nothing stopping the bridge usage of those types for implementing those methods since the basic functionality of the methods needed for _ObjectiveCBridgeable work just fine on any platform.

[colemancda]

@phausler, Ok thanks. Also, I see NSUUID is not converted to Swift 3, could I work on that today? https://github.com/apple/swift-corelibs-foundation/blob/swift-3/Foundation/NSUUID.swift

[phausler]

UUID has some cross platform strangeness since it uses the Darwin uuid type, we have to make certain there is parity there to the overlay version. So you would need to drop the _ObjectiveCBridgeable and also figure out how we could import the uuid library correctly on linux

[colemancda]

I have used https://github.com/PureSwift/CUUID in the past, but that won't be acceptable for this implementation. I have also tried to have a PR accepted to the Swift repo to fix this, but that was denied swiftlang/swift#276 .

I can adapt the code to use the Unix UUID library, basically copy the Swift Darwin Foundation overlay, and then we can work on importing that lib on Linux. @phausler Sounds good?

[colemancda]

@phausler Added PR for UUID type #417

[colemancda]

@phausler @belkadan Submitted PR to Swift for importing UUID library. swiftlang/swift#3095

[colemancda]

@phausler Could you comment on this PR please? swiftlang/swift#3095 (comment)

I believe it would solve the issue for importing libUUID on Linux.

[colemancda]

Made a cleaner PR for CUUID swiftlang/swift#3107

[swift-ci]

Comment by Paulo Ricardo Lopes de Faria (JIRA)

Is anybody working on Data?

[phausler]

Data is already done. https://github.com/apple/swift-corelibs-foundation/blob/master/Foundation/Data.swift