[Feature Request]: .NET 6 Target with Trimming

[ds5678]

Context

This is a repost of #2673.

A .NET 6 target for the decompiler project with trimming would allow this to be used in trimmed or NativeAOT-compiled applications. This allows for applications to be smaller, faster, and more independent of user software installations.

Issues to be handled

• A bunch of Linq polyfills need excluded on .NET 6 with preprocessor directives.
• ResXResourceWriter.cs uses TypeDescriptor.GetConverter and BinaryFormatter.Serialize.
• UniversalAssemblyResolver.cs calls Type.GetType("Mono.Runtime") which I think can be safely excluded with a preprocessor directive on .NET 6.
• 6a6e82c added ReferenceAssemblyAnnotator which breaks when targeting multiple frameworks [Bug]: Breaks with multiple framework targets tunnelvisionlabs/ReferenceAssemblyAnnotator#92

Nullable Attributes

The issue mentioned in the last bullet point still hasn't been resolved. However, I have some alternatives:

• Nullable is a polyfill for nullable attributes.
• PolySharp is a polyfill for many classes, including nullable attributes. This would allow ILSpy to use additional C# language features in its codebase.

Both of these are more actively maintained, and neither of them exhibit the issue that prevents multi-targeting.

On a more practical note, PolySharp has support for MemberNotNullAttribute and MemberNotNullWhenAttribute, which ReferenceAssemblyAnnotator does not.

[christophwille]

MEF and NativeAot? Don't know if that will work.

[ds5678]

MEF

Is this referring to the Managed Extensibility Framework?

Edit: Yes it is.

[ds5678]

MEF and NativeAot? Don't know if that will work.

Even if trimming isn't feasible, do you mind if I do a pull request for PolySharp and .NET 6?

[dgrunwald]

I don't see a need to introduce PolySharp here. We should be able to use ReferenceAssemblyAnnotator for .NET Core 2; and we shouldn't need anything extra at all for .NET 6?

[ds5678]

I don't see a need to introduce PolySharp here.

If nothing else, you'll be able to use MemberNotNullAttribute and MemberNotNullWhenAttribute which are not available from ReferenceAssemblyAnnotator.

However, PolySharp also inserts numerous other classes, such as [UnscopedRef], which could potentially benefit your customers if used in ILSpy.

[christophwille]

Unless a customer specifically asks for that we won't do it. Just because is not a valid justification.

[ds5678]

It sounds like I am not welcome here.