Source-build: [ArPow] Onboard linker to arcade-powered source-build

[crummel]

[omajid]

PR: https://github.com/mono/linker/pull/1823

[omajid]

PR was merged; can someone please look over the internal build to make sure things are okay?

[MichaelSimons]

I took a look at the internal build and noted the following:

1. There are a number of System.* prebuilts that look like they would get resolved by adding a Version.Details.xml reference to SBRP.
   <Dependency Name="Microsoft.SourceBuild.Intermediate.source-build-reference-packages" Version="5.0.0-alpha.1.20473.1"> <Uri>https://github.com/dotnet/source-build-reference-packages</Uri> <Sha>def2e2c6dc5064319250e2868a041a3dc07f9579</Sha> <SourceBuild RepoName="source-build-reference-packages" ManagedOnly="true" /> </Dependency>

Update: Per https://github.com/dotnet/source-build/issues/2085, we do not want to reference source-build-reference-packages

1. I noticed in the resulting intermediate NuGet package that three packages are getting produced from the build. In 5.0, there is only one. I confirmed with @dseefeld, that he only sees one in his non-ArPow 6.0 changes as well. Functionally this by itself is not an issue. The concern is this may be a source of additional prebuilts that we haven't encountered before.

5.0 artifacts

• Microsoft.NET.ILLink.Tasks

6.0 ArPow artifacts

• Microsoft.NET.ILLink
• Microsoft.NET.ILLink.Analyzers
• Microsoft.NET.ILLink.Tasks

[omajid]

There's something strange about Microsoft.NET.ILLink.Analyzers.

$ ag Microsoft.NET.ILLink.Analyzers
src/ILLink.RoslynAnalyzer/ILLink.RoslynAnalyzer.csproj
14:    <PackageId>Microsoft.NET.ILLink.Analyzers</PackageId>

So the ILLink.RoslynAnalyzer project (which produces ILLink.RoslynAnalyzer.dll) produces the nuget package Microsoft.NET.ILLink.Analyzers.

ILLink.RoslynAnalzyer.dll itself is shipped with the 6.0 Preview 2 SDK:

$ tar tf ~/downloads/dotnet-sdk-6.0.100-preview.2.21155.3-linux-x64.tar.gz | grep -E -i 'illink[^/]*\.dll' | grep -v resources
./sdk/6.0.100-preview.2.21155.3/Sdks/Microsoft.NET.Sdk/analyzers/ILLink.RoslynAnalyzer.dll
./sdk/6.0.100-preview.2.21155.3/Sdks/Microsoft.NET.ILLink.Tasks/tools/net5.0/illink.dll
./sdk/6.0.100-preview.2.21155.3/Sdks/Microsoft.NET.ILLink.Tasks/tools/net5.0/ILLink.Tasks.dll
./sdk/6.0.100-preview.2.21155.3/Sdks/Microsoft.NET.ILLink.Tasks/tools/net472/ILLink.Tasks.dll

The Microsoft.NET.ILLink.Tasks package does not include this rolsyn dll:

$ unzip -l artifacts/packages/Release/Shipping/Microsoft.NET.ILLink.Tasks.6.0.100-dev.nupkg | grep -i roslyn

It seems like we would break the SDK build if we were to remove this and disallow prebuilts.

[omajid]

Comparing with 5.0 sdk, the 5.0 SDK doesn't include illink.roslynanalyzers:

$ tar tf dotnet-microsoft-built-sdk-5.0.104.tar.gz | grep -i link
./sdk/5.0.104/Sdks/Microsoft.NET.Sdk/targets/Microsoft.NET.ILLink.targets
./sdk/5.0.104/Sdks/Microsoft.NET.ILLink.Tasks/
./sdk/5.0.104/Sdks/Microsoft.NET.ILLink.Tasks/tools/
./sdk/5.0.104/Sdks/Microsoft.NET.ILLink.Tasks/tools/netcoreapp3.0/
./sdk/5.0.104/Sdks/Microsoft.NET.ILLink.Tasks/tools/netcoreapp3.0/ILLink.Tasks.dll
./sdk/5.0.104/Sdks/Microsoft.NET.ILLink.Tasks/tools/netcoreapp3.0/ILLink.Tasks.deps.json
./sdk/5.0.104/Sdks/Microsoft.NET.ILLink.Tasks/tools/netcoreapp3.0/illink.runtimeconfig.json
./sdk/5.0.104/Sdks/Microsoft.NET.ILLink.Tasks/tools/netcoreapp3.0/illink.dll
./sdk/5.0.104/Sdks/Microsoft.NET.ILLink.Tasks/tools/netcoreapp3.0/Mono.Cecil.dll
./sdk/5.0.104/Sdks/Microsoft.NET.ILLink.Tasks/tools/netcoreapp3.0/illink.deps.json
./sdk/5.0.104/Sdks/Microsoft.NET.ILLink.Tasks/tools/netcoreapp3.0/Mono.Cecil.Pdb.dll
./sdk/5.0.104/Sdks/Microsoft.NET.ILLink.Tasks/tools/net472/
./sdk/5.0.104/Sdks/Microsoft.NET.ILLink.Tasks/tools/net472/ILLink.Tasks.dll
./sdk/5.0.104/Sdks/Microsoft.NET.ILLink.Tasks/tools/net472/System.Reflection.Metadata.dll
./sdk/5.0.104/Sdks/Microsoft.NET.ILLink.Tasks/tools/net472/Mono.Cecil.dll
./sdk/5.0.104/Sdks/Microsoft.NET.ILLink.Tasks/tools/net472/System.Collections.Immutable.dll
./sdk/5.0.104/Sdks/Microsoft.NET.ILLink.Tasks/Icon.png
./sdk/5.0.104/Sdks/Microsoft.NET.ILLink.Tasks/Sdk/
./sdk/5.0.104/Sdks/Microsoft.NET.ILLink.Tasks/Sdk/Sdk.props
$ tar tf dotnet-microsoft-built-sdk-5.0.104.tar.gz | grep -i illink | grep -i roslyn

The analyzer was a recent addition, post 5.0: https://github.com/mono/linker/pull/1563

[MichaelSimons]

Thanks @omajid, That explains the Microsoft.NET.ILLink.Analyzers package. What about the Microsoft.NET.ILLink package? I'm not seeing an SDK reference?

[omajid]

That one just contains illink.dll and resources. The dll here should already be included in the Microsoft.NET.ILLink package; could it really be bringing in additional dependencies?

unzip -l ./artifacts/source-build/self/src/artifacts/packages/Release/Shipping/Microsoft.NET.ILLink.6.0.100-dev.nupkg | awk '{ print $4 }'

Name
----
_rels/.rels
Microsoft.NET.ILLink.nuspec
lib/net5.0/cs/illink.resources.dll
lib/net5.0/de/illink.resources.dll
lib/net5.0/es/illink.resources.dll
lib/net5.0/fr/illink.resources.dll
lib/net5.0/it/illink.resources.dll
lib/net5.0/ja/illink.resources.dll
lib/net5.0/ko/illink.resources.dll
lib/net5.0/pl/illink.resources.dll
lib/net5.0/pt-BR/illink.resources.dll
lib/net5.0/ru/illink.resources.dll
lib/net5.0/tr/illink.resources.dll
lib/net5.0/zh-Hans/illink.resources.dll
lib/net5.0/zh-Hant/illink.resources.dll
lib/net5.0/illink.runtimeconfig.json
lib/net5.0/illink.dll
ref/net5.0/illink.dll
Icon.png
[Content_Types].xml
package/services/metadata/core-properties/389e43d829f24d9591523fc462093b43.psmdcp

Do you think it's worth removing it?

[MichaelSimons]

Sorry, I should have cracked it open. It is curious though why this was excluded in past releases of source-build. If it is discovered to present a problem down the road, we can address it them. It would be better to avoid source-build "specializations" if not needed. Closing.

[omajid]

Thanks for making me double check things!