Nullable annotations for projects using XamlX

[MrJul]

What does the pull request do?

This PR enables nullable reference types in projects using XamlX:

• Build.Tasks
• Designer.HostApp
• Generators
• Markup.Xaml.Loader

Depends on kekekeks/XamlX#121

Notes

The Generators project directly uses <Nullable>enable</Nullable> instead of including NullableEnable.props. This props file disables nullable warnings for netstandard2.0 as they're usually handled by the net8.0 build, which isn't targeted by this project.

Several methods in RoslynTypeSystem now throw NotSupportedException instead of returning null, to match the other implementations. These methods are normally not called by the name generator (or they would have failed with a NullReferenceException before).

[MrJul]

Apparently hitting a compiler bug regarding local functions and nullability - I can't reproduce locally and there's no warning either in XamlX pipelines. I'm updating the SDK here to see if that solves it.

Edit: it does.

[MrJul]

And now hitting a bug in ILRepack! See Gillibald/il-repack#1

[maxkatz6]

@MrJul could it be that ILRepack bug was fixed in the upstream? https://github.com/gluck/il-repack
It was recently revived and made active again

[MrJul]

@MrJul could it be that ILRepack bug was fixed in the upstream? https://github.com/gluck/il-repack It was recently revived and made active again

Indeed, these changes are similar to mine:

gluck/il-repack@15d48ef#diff-c49a81a215a1a411a33ee869d718122208bbfe89696ef5a091322ca938ee32e9R927-R936

Thanks for letting me know! We should probably discard the fork and use the new official version.

[MrJul]

Note: ILRepack only supported .NET Framework, so I started porting it to .NET 8 a while back. While the projects compiled, I didn't have the time to update the custom NuGet pack targets yet, which was necessary to open a valid PR.

Meanwhile, ILRepack got another PR adding dotnet tool support: gluck/il-repack#364
Contrary to my fork, it doesn't update the ILRepack.Lib to .NET 8 which I intended to use. However, I think we're completely fine with using the tool in the build tasks.

I've updated this PR to use the tool. Assemblies are now merging without errors.

[avaloniaui-bot]

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[avaloniaui-bot]

You can test this PR using the following package version. 11.2.999-cibuild0050578-alpha. (feed url: https://nuget-feed-all.avaloniaui.net/v3/index.json) [PRBUILDID]

[avaloniaui-bot]

You can test this PR using the following package version. 11.2.999-cibuild0050623-alpha. (feed url: https://nuget-feed-all.avaloniaui.net/v3/index.json) [PRBUILDID]