Fix build when using source generators (#6534)

[singhashish-wpf]

Fixes #6522
Fixes dotnet/roslyn#60257

Description

Fixes the build when using source generators.

Customer Impact

Without this PR, customers cannot build a WPF application with source generators.

Regression

No. To my knowledge, it never worked.

Testing

Tested by building a blank WPF application that uses the Regex source generator. This PR fixed the build.

Risk

Low.

/cc @RussKie (It looks like your hunch about the Analyzers property was right)

Microsoft Reviewers: Open in CodeFlow

Microsoft Reviewers: Open in CodeFlow

[ghost]

Hi @singhashish-wpf. Please make sure you've updated the PR description to use the Shiproom Template. Also, make sure this PR is not marked as a draft and is ready-to-merge.

To learn more about how to prepare a servicing PR click here.

[RussKie]

/cc: @ThomasGoulet73

[danmoseley]

@jaredpar , tactics wondered whether a compiler feature like this ought to have a minimal test for each appmodel upstream. I see the Roslyn repo has some test projects that use WPF in connection with code analysis. If one of those used a source generator, would it have caught this bug?

[mmitche]

Merge when ready, we are past 6.0.7 code complete.

[jlaanstra]

@singhashish-wpf After updating to the latest .NET 6 SDK released today, analyzers are now passed twice to the CoreCompile target in the WPF generated project. Some analyzers don't like this and fail with "The namespace already contains a type ".

Analyzers are now explicitly listed in the generated project and also imported by the ResolveLockFileAnalyzers target, resulting in duplicates.

[ThomasGoulet73]

@jlaanstra Could you provide a repro ? Analyzers need to be run twice because of source generators and the way Baml compilation requires CoreCompile to be run twice (Once for the generated project and once for the main project).

[DavidBergstromSWE]

@singhashish-wpf Since update my WPF application using Microsoft MVVM Toolkit reports errors CS0579 (duplicate attribute) and CS0111 (duplicate member declaration) at compile time, possibly connected to source generators in the toolkit:

[jamesport079]

@singhashish-wpf Since update my WPF application using Microsoft MVVM Toolkit reports errors CS0579 (duplicate attribute) and CS0111 (duplicate member declaration) at compile time, possibly connected to source generators in the toolkit:

same problem

[Chris-Dickerson]

DevExpress.Mvvm.CodeGenerators doesn't like this update either.

[ThomasGoulet73]

This seems to be a bug with Analyzers from nuget packages. I'll try to prepare a fix soon. This PR fixed Source Generators from the SDK but broke Source Generators coming from nuget packages.

[Chris-Dickerson]

global.json workaround works for me -- #6792

[ThomasGoulet73]

Edit: See #6792 (comment) for a better workaround.

Here's another workaround that works when using the SDK from .Net 6.0.7. Add this to the project file:

  <Target Name="WorkaroundRemoveAnalayzers" BeforeTargets="GenerateTemporaryTargetAssembly">
    <ItemGroup>
      <_TempWorkaroundAnalyzer Include="@(Analyzer)" />
      <Analyzer Remove="@(Analyzer)" />
    </ItemGroup>
  </Target>

  <Target Name="WorkaroundAddAnalayzers" AfterTargets="GenerateTemporaryTargetAssembly">
    <ItemGroup>
      <Analyzer Include="@(_TempWorkaroundAnalyzer)" />
    </ItemGroup>
  </Target>

This will revert the behavior to .Net 6.0.6 where Source Generators coming from Nuget packages will work while Source Generators coming from an SDK will not.

[jlaanstra]

@ThomasGoulet73 I have a binlog that I can't publicly share. Msft employes can reach out internally if they need it.

I'm using the following workaround which allows both scenarios to work:

<Target Name="RemoveDuplicateAnalyzers" BeforeTargets="CoreCompile">

        <RemoveDuplicates Inputs="@(Analyzer)">
            <Output
                TaskParameter="Filtered"
                ItemName="FilteredAnalyzer"/>
        </RemoveDuplicates>

        <ItemGroup>
            <Analyzer Remove="@(Analyzer)" />
            <Analyzer Include="@(FilteredAnalyzer)" />
        </ItemGroup>
    </Target>

[rmarinho]

What will be the correct fix and where can i follow it ? on the .net sdk itself ?

[hahyes]

What will be the correct fix and where can i follow it ? on the .net sdk itself ?

In 6.0.9 release. Current fix is hanging in 6.0.9 milestone.

[LeonSpors]

@ThomasGoulet73 I have a binlog that I can't publicly share. Msft employes can reach out internally if they need it.

I'm using the following workaround which allows both scenarios to work:

<Target Name="RemoveDuplicateAnalyzers" BeforeTargets="CoreCompile">

        <RemoveDuplicates Inputs="@(Analyzer)">
            <Output
                TaskParameter="Filtered"
                ItemName="FilteredAnalyzer"/>
        </RemoveDuplicates>

        <ItemGroup>
            <Analyzer Remove="@(Analyzer)" />
            <Analyzer Include="@(FilteredAnalyzer)" />
        </ItemGroup>
    </Target>

Thanks for the workaround.