Projection tooling for Swift interop in .NET 10

[kotlarmilos]

Overview

This issue tracks the progress of implementing and shipping the projection tooling for .NET 10. The primary goal is to release the projection tooling as an experimental NuGet CLI capable of generating bindings for a specific set of Swift APIs, as defined in the use cases. It should follow general principles outlined in the Swift interop proposal.

Currently, the projection tooling is available as an experimental NuGet CLI in dotnet-experimental feed.

Tasks:

• [ ] Design and implement Swift language features in C#
  • [ ] Generics
  • [ ] Enums
  • [ ] Classes / Actors
  • [ ] Protocols and associated types
  • [ ] Any/Some/Never
    • [ ] Design and implement Swift runtime support
  • [ ] Metadata
  • [ ] Conformance descriptors
  • [ ] Witness tables
  • [ ] Existential containers
  • [ ] Common interfaces (IEnumerable, ICollection, IDisposable, etc)
• [ ] Design and implement memory management
  • [ ] Memory management between Swift and C#
  • [ ] Memory management between Objective-C and Swift interops
  • [ ] Review memory management of the projected pointer types
• [ ] Design and implement the projection tooling
  • [ ] https://github.com/dotnet/runtimelab/issues/2582
    • [ ] ABI/MachO parser
    • [ ] String-based emitter
  • [ ] Demangler
    • [ ] https://github.com/dotnet/runtimelab/issues/2664
    • [x] https://github.com/dotnet/runtimelab/issues/2691
    • [ ] https://github.com/dotnet/runtimelab/issues/2665
  • [ ] Type registrar / Typedecl / Typespec
• [ ] Testing and validation
  • [ ] Consolidate the existing tests (level of granularity)
  • [ ] Setup iOS/MacCatalyst tests with Native AOT
  • [ ] Swift framework testing
  • [ ] App submission tests to App Store
• [ ] https://github.com/dotnet/runtimelab/issues/2586
• [ ] Shipping
  • [ ] Move projection tooling to the xamarin-macios
  • [ ] Move generated bindings to the xamarin-macios
  • [ ] Move the sample app with use-cases to the xamarin-macios

[!NOTE]
The projection tooling will be experimental in .NET 10.

[ghost]

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Issue Details

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# Description This issue tracks the work for adapting the existing [Binding Tools for Swift](https://github.com/xamarin/binding-tools-for-swift) and shipping it as a product in .NET 9. The projection tooling consists of three main areas: Importing Swift into .NET, Exporting .NET to Swift, and distribution. Below is a list of tasks that needs to be implemented. Please note that the breakdown of the issues does not impose hard deadlines. If some of the functionality does not get upstreamed for a particular preview version, this issue will be updated accordingly. ## Tasks ### .NET9 Preview 1 - [ ] Update documentation to specify tool's layout - [ ] Update documentation to specify type representations - [ ] Create a NuGet package for the BTfS - [ ] Ensure that the NuGet package is shipped for supported platforms such as OSX and Apple mobile ### .NET9 Preview 2 - [ ] Adapt the tool to work with the new runtime support - [ ] Add Roslyn source generators to generate Swift metadata for selected assemblies ### .NET9 Preview 3 TBD

Author:	kotlarmilos
Assignees:	kotlarmilos, stephen-hawley
Labels:	`area-Meta`, `User Story`
Milestone:	9.0.0

[stephen-hawley]

Might want to include "Update BTfS to run on .NET 7 and later" - I'm in the middle of that right now.