CA1873 potential false positive for non-expensive logging parameters

[joshuahills]

Describe the bug

The CA1873 analyzer enabled by default in .NET 10 is flagging the log call in the below minimal repro for a logging parameter that is not expensive. The examples in the docs make sense, however this does not. Is this intended behaviour and all log messages should now be wrapped in an if (logger.IsEnabled(...)) block?

To Reproduce

Minimal repro: https://github.com/joshuahills/ca1873-false-positive

1. Clone repo
2. Build solution
3. Observe build error

Exceptions (if any)

n/a

Further technical details

details of dotnet --info

.NET SDK: Version: 10.0.100 Commit: b0f34d51fc Workload version: 10.0.100-manifests.5fb86115 MSBuild version: 18.0.2+b0f34d51f

Runtime Environment:
OS Name: Windows
OS Version: 10.0.26100
OS Platform: Windows
RID: win-x64
Base Path: C:\Program Files\dotnet\sdk\10.0.100\

Microsoft Visual Studio Professional
Channel: Insiders
Version: Insiders [11218.70]

[joshuahills]

I see #51818 has been merged which will improve this sufficiently.

[KalleOlaviNiemitalo]

I guess it's because of the implicit array allocation for params object?[] args.

sdk/src/Microsoft.CodeAnalysis.NetAnalyzers/src/Microsoft.CodeAnalysis.NetAnalyzers/Microsoft.NetCore.Analyzers/Performance/AvoidPotentiallyExpensiveCallWhenLogging.cs

Lines 117 to 120 in e6bc966

	if (operation is IArrayCreationOperation arrayCreationOperation)
	{
	return !IsEmptyImplicitParamsArrayCreation(arrayCreationOperation);
	}

The reason of the IsEmptyImplicitParamsArrayCreation check there seems to be that Roslyn uses Array.Empty<T>() for an empty params array and that does not cost an allocation every time.