CA1812 should not warn for top-level Program classes

[martincostello]

Analyzer

Diagnostic ID: CA1812

Describe the improvement

An application that uses top-level programs and uses an analysis rule set that includes CA1812 will generate a warning from the compiler-generated Program class in even a trivial application.

Console.WriteLine("Hello, World!");

Program.cs(1,1): warning CA1812: Program is an internal class that is apparently never instantiated. If so, remove the code from the assembly. If this class is intended to contain only static members, make it static (Shared in Visual Basic). [Project.csproj]

This then requires the developer to suppress it like so:

#pragma warning disable CA1812
Console.WriteLine("Hello, World!");

Describe suggestions on how to achieve the rule

Special-case compiler-generated Program classes for top-level programs and do not emit the violation.

Additional context

Application that reproduces the problem adapted from dotnet new console using the .NET 6 RC2 SDK.

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <AnalysisMode>AllEnabledByDefault</AnalysisMode>
    <EnableNETAnalyzers>true</EnableNETAnalyzers>
    <ImplicitUsings>enable</ImplicitUsings>
    <NoWarn>$(NoWarn);CA1014;CA1303</NoWarn>
    <Nullable>enable</Nullable>
    <OutputType>Exe</OutputType>
    <TargetFramework>net6.0</TargetFramework>
  </PropertyGroup>
</Project>

Console.WriteLine("Hello, World!");

[mavasani]

I think this was recently fixed by @Youssef1313

[Youssef1313]

Yeah I believe it should have been fixed. Not aware which version contains the fix though.

[Youssef1313]

@martincostello Can you try with https://dev.azure.com/dnceng/public/_packaging?_a=package&feed=dotnet7&package=Microsoft.CodeAnalysis.NetAnalyzers&version=7.0.0-preview1.21513.1&protocolType=NuGet ?

[martincostello]

Anything required beyond adding the package? Doesn't seem to have any effect if I add the relevant feed to nuget.config and add this to the project file:

  <ItemGroup>
    <PackageReference Include="Microsoft.CodeAnalysis.NetAnalyzers" Version="7.0.0-preview1.21513.1">
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
      <PrivateAssets>all</PrivateAssets>
    </PackageReference>
  </ItemGroup>

[Youssef1313]

Likely fixed in #5351.

[mavasani]

Thanks @Youssef1313

[adamralph]

This still occurs in the latest RC (6.0.100-rc.2.21505.57), see https://github.com/adamralph/minver/runs/4132244037?check_suite_focus=true

Weirdly, it's only a problem on Windows and MacOS, but not Linux.

Is the intention to fix this before RTM?

[Youssef1313]

It looks like the milestone for #5351 was set to .NET 7.

@mavasani @jmarolf Can this get in .NET 6?

[martincostello]

Yeah I've seen this not fixed in 6.0.0/6.0.100 either, but that's already been built and ships today so would need backporting to 6.0.1.

[adamralph]

@martincostello I realise RTM is tomorrow, but all I see at https://dotnet.microsoft.com/download/dotnet/6.0 is 6.0.100-rc.2.21505.57.

[martincostello]

I believe it's shipping today ahead of .NET Conf tomorrow - the 6.0.0 packages are all in NuGet.org now (I woke up this morning to various dependabot updates), and the 6.0.100 SDK has been present at the URL it lives at for CI scripts for a week or so. They just haven't updated the releases.json file (which powers the .NET website's download links) yet.

[jmarolf]

It looks like the milestone for #5351 was set to .NET 7.

Manish Vasani Jonathon Marolf Can this get in .NET 6?

sadly, no by the time the fix was merged final builds of .NET 6 were already spinning for today. Considering CA1812 is off by default I don't think this meets the bar to port as a day 0 fix. but I will pursue it for the 6.0.200 SDK release

[michha]

@jmarolf
Will this be fixed in 6.0.200 SDK? Is there a rough timeline for its release?

[Grauenwolf]

It is fixed in 7.0.0-preview1.22168.1.

	<ItemGroup>
		<PackageReference Include="Microsoft.CodeAnalysis.NetAnalyzers" Version="7.0.0-preview1.22168.1">
			<IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
			<PrivateAssets>all</PrivateAssets>
		</PackageReference>
	</ItemGroup>

[Youssef1313]

@jmarolf @mavasani This one is already fixed, but for 7.x.

The request here for this issue is backporting to 6.x. I don't know if it meets the bar for backporting. If not, can we close?

[MrDaedra]

Any updates on this fix?

@Youssef1313 as .NET 6 is in LTS it makes sense to backport it

[Youssef1313]

@Youssef1313 as .NET 6 is in LTS it makes sense to backport it

@mavasani @jmarolf Can you comment on whether this can be backported?

[mavasani]

Tagging @buyaa-n

[buyaa-n]

As @jmarolf mentioned the analyzer is off by default and there is a workaround (suppress), therefore this does not meet the bar for servicing 6.0, I guess it could be considered if 1st party customer requesting it

[BryceBarbara]

Just to share with others who might be encountering this, I was able to disable this for all projects in my solution by putting this in the .editorconfig

# Workaround for https://github.com/dotnet/roslyn-analyzers/issues/5628
[Program.cs]
dotnet_diagnostic.ca1812.severity = none

[Youssef1313]

Closing as this is fixed in 7.x and doesn't meet the bar to backport for 6.x

[kimsey0]

Which version is this fixed from? I'm still getting a warning if I create a new console project and enable the Recommended analysis mode with the .NET SDK version 7.0.101.

[Youssef1313]

@kimsey0 I think the fix didn't yet flow into the .NET SDK.

Can you try with 7.0.0 from NuGet.org?

[kimsey0]

That does indeed seem to fix it. I just assumed that since Microsoft.CodeAnalysis.NetAnalyzers 7.0.0 was released on December 8th and .NET SDK 7.0.1 was released on December 13th, it would include the newest analyzers, but there might be a bit of a delay for the flow. (7.0.1 is also marked as a security patch, so I don't know if that influences anything.)

I hope the analyzer changes will be out in the next SDK release. :-)

[dotnetshadow]

When I try with nuget 7.0.1 version I still get the issue?