Fix SA1023 for C# 9 function pointer parameters

[nxtn]

No description provided.

[codecov]

Codecov Report

Merging #3252 (56fa929) into master (aa26bda) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #3252   +/-   ##
=======================================
  Coverage   94.39%   94.40%           
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  Files         967      969    +2     
  Lines      108429   108525   +96     
  Branches     3675     3677    +2     
=======================================
+ Hits       102356   102452   +96     
  Misses       5143     5143           
  Partials      930      930           

[sharwell]

💡 IIRC, the unmanaged keyword only works for .NET 5 and newer. I believe there are some instances of tests in the repository using ReferenceAssemblies.Net.Net50 explicitly. Considering function pointers are only officially supported for .NET 5 and newer, it would be fine to just update this test to always use it and test both managed and unmanaged cases. I'm happy to leave this for a follow-up PR though.

[nxtn]

Well... error CS8889: The target runtime doesn't support extensible or runtime-environment default calling conventions.

[sharwell]

The compiler is looking for this field, which is only available in .NET 5 and newer:
https://github.com/dotnet/runtime/blob/2445324a501efaca19e136b7a7ca46d8ab5d95ec/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/RuntimeFeature.cs#L18-L21

[nxtn]

Shall I specify a calling convention to make the build pass as in #3254?

[sharwell]

I'd prefer the test be updated to this form instead:

StyleCopAnalyzers/StyleCop.Analyzers/StyleCop.Analyzers.Test.CSharp9/NamingRules/SA1300CSharp9UnitTests.cs

Lines 41 to 54 in 6399f49

	await new CSharpTest(LanguageVersion.CSharp9)
	{
	ReferenceAssemblies = GenericAnalyzerTest.ReferenceAssembliesNet50,
	TestCode = testCode,
	ExpectedDiagnostics =
	{
	// /0/Test0.cs(2,15): warning SA1300: Element 'r' should begin with an uppercase letter
	Diagnostic().WithLocation(0).WithArguments("r"),
	// /0/Test0.cs(2,15): warning SA1300: Element 'r' should begin with an uppercase letter
	Diagnostic().WithLocation(0).WithArguments("r"),
	},
	FixedCode = fixedCode,
	}.RunAsync(CancellationToken.None).ConfigureAwait(false);

[sharwell]

Thanks @NextTurn !