Roslyn-analyzers: FxCop rule CA1062: Validate arguments of public methods, do not recognize ValidatedNotNullAttribute in NullCheck helper classes

[xmarshal]

Analyzer package

Example: Microsoft.CodeAnalysis.FxCopAnalyzers

Package Version

v2.9.0-beta1.final+321600d1

Diagnostic ID

CA1062

Repro steps

1. clone https://github.com/xmarshal/CodeAnalysisIssues
2. build

Expected behavior

no warning or errors

Actual behavior

CA1062 In externally visible method 'string Ca1062Repro.ToString(object param)', validate parameter 'param' is non-null before using it. If appropriate, throw an ArgumentNullException when the argument is null or add a Code Contract precondition asserting non-null argument. CodeAnalysis1062 Ca1062Repro.cs 15

[xmarshal]

what with this Issue, it's important for our production

[mavasani]

Thanks, I agree this needs to be fixed. It will likely only be fixed in version 2.9.x. I am going out on vacation for few weeks starting today, I will get to it once I am back.

[mavasani]

This might likely be fixed by https://github.com/dotnet/roslyn-analyzers/pull/2345/. I will validate once that PR is merged to use the corresponding NuGet package for https://github.com/xmarshal/CodeAnalysisIssues

[mavasani]

Ah, I looked at your repro, and the issue seems to be that the helper method performing null checks is in a different project/compilation. Roslyn analyzers do not support interprocedural analysis across project/compilation boundary, so the invocation into a different project is not analyzed and leads to the analysis flagging this case. If I copy the code from Annotations.csproj into CodeAnalysis1062.csproj, analysis correctly detects the validation.

Unfortunately, this behavior is by design for the current analysis support in Roslyn analyzers.

[mavasani]

Kindly file an issue on the https://github.com/dotnet/roslyn/issues if you believe cross assembly analysis support is critical for Roslyn analyzers. Closing this issue as by design.

[thorhj]

@mavasani
I have tried adding a helper method to a NuGet package using Args.cs.pp file transformation:

using System;

namespace $RootNamespace$
{
    public static class Args
    {
        public static void NotNull([ValidatedNotNull]object value)
        {
            if (value == null)
            {
                throw new ArgumentNullException(message);
            }
        }
    }

    [AttributeUsage(AttributeTargets.Parameter, Inherited = false)]
    public sealed class ValidatedNotNullAttribute : Attribute
    {
    }
}

This does not work either; CA1062 is still being reported. Does your explanation above cover this scenario, or should this approach work?