Fix S1854 Performance: Rule can be very slow in some scenarios

[costin-zaharia-sonarsource]

Description

Source: https://community.sonarsource.com/t/azure-devops-build-stuck-after-migrating-from-sq-9-1-to-sq-9-2/56783

When analyzing the reproducer project created by our user, the rule https://rules.sonarsource.com/csharp/RSPEC-1854 increased the build time from ~1m to ~130m.

I can reproduce the issue on my side and it was confirmed by the user that deactivating the rule will fix the problem.

At the first glance the problem is in the new CFG generation code since IOperationWrapperSonar has 48.4% of the memory allocations (considering only our code):

and uses a significant part of the processor time:

Repro steps

Analyze the repro project created by the user.

Expected behavior

The analysis finishes in a reasonable time.

Actual behavior

The total build time increases from 1m without the rule, to 130m when the rule is active.

Known workarounds

Removing the rule from the quality profile.

Related information

• C#/VB.NET Plugins version: https://github.com/SonarSource/sonar-dotnet/releases/tag/8.35.0.42613
• MSBuild / dotnet version: 6.0.101
• SonarScanner for .NET version: SonarScanner for MSBuild 5.4.1
• Operating System: Windows
• Please ask me for the reproducer.

[pavel-mikula-sonarsource]

Also reported in #5382 by @rauhs:

PackageReference Include="SonarAnalyzer.CSharp" Version="8.33.0.40503"

Analyzer Summary
    14:22.455   SonarAnalyzer.CSharp, Version=8.33.0.0, Culture=neutral, PublicKeyToken=c5b62af9de6d7244
        SonarAnalyzer.Rules.CSharp.DeadStores (S1854) = 6:25.949
        SonarAnalyzer.Rules.CSharp.PrivateFieldUsedAsLocalVariable (S1450) = 1:22.248
        SonarAnalyzer.Rules.CSharp.ClassAndMethodName (S100, S101) = 23.728 s
        [...]
    2:32.987   Microsoft.CodeAnalysis.NetAnalyzers, Version=6.0.5.1901, Culture=neutral, PublicKeyToken=31bf3856ad364e35
        Microsoft.CodeQuality.Analyzers.Maintainability.AvoidDeadConditionalCode (CA1508) = 47.422 s
        Microsoft.NetCore.Analyzers.Security.ReviewCodeForInformationDisclosureVulnerabilities (CA3004) = 20.500 s
        Microsoft.NetCore.Analyzers.Runtime.DisposeObjectsBeforeLosingScope (CA2000) = 16.725 s
        [...]

I've reported it also to Roslyn: dotnet/roslyn-analyzers#5870

[pavel-mikula-sonarsource]

@rauhs Can you share a reproducer with us? By public or private channel.

[pavel-mikula-sonarsource]

Side effect: Memory allocation issue is fixed in #5401

[pavel-mikula-sonarsource]

This doesn't reproduce on my machine. I can rebuild it with all rules in 10 minutes. There are things to improve, but they are not the root cause of this.