Handle OnSerializedAttribute (RCS1163)

ChangeLog.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Fix analyzer [RCS1124](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1124) ([PR](https://github.com/dotnet/roslynator/pull/1279))
 - Fix analyzer [RCS0058](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS0058) ([PR](https://github.com/dotnet/roslynator/pull/1281))
+- Fix analyzer [RCS1163](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1163) ([PR](https://github.com/dotnet/roslynator/pull/1280))
 
 ## [4.6.4] - 2023-11-24
 

src/Analyzers/CSharp/Analysis/UnusedParameter/UnusedParameterAnalyzer.cs

@@ -2,6 +2,7 @@
 
 using System.Collections.Generic;
 using System.Collections.Immutable;
+using System.Diagnostics;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
@@ -14,6 +15,14 @@ namespace Roslynator.CSharp.Analysis.UnusedParameter;
 [DiagnosticAnalyzer(LanguageNames.CSharp)]
 public sealed class UnusedParameterAnalyzer : BaseDiagnosticAnalyzer
 {
+    private static readonly MetadataNameSet _attributes = new(new[]
+        {
+            MetadataName.Parse("System.Runtime.Serialization.OnSerializedAttribute"),
+            MetadataName.Parse("System.Runtime.Serialization.OnDeserializedAttribute"),
+            MetadataName.Parse("System.Runtime.Serialization.OnSerializingAttribute"),
+            MetadataName.Parse("System.Runtime.Serialization.OnDeserializingAttribute"),
+        });
+
     private static ImmutableArray<DiagnosticDescriptor> _supportedDiagnostics;
 
     public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics
@@ -134,7 +143,7 @@ private static void AnalyzeMethodDeclaration(SyntaxNodeAnalysisContext context)
 
             walker.SetValues(context.SemanticModel, context.CancellationToken);
 
-            FindUnusedNodes(parameterInfo, walker);
+            FindUnusedNodes(parameterInfo, walker, methodSymbol);
 
             if (walker.Nodes.Count > 0
                 && !MethodReferencedAsMethodGroupWalker.IsReferencedAsMethodGroup(methodDeclaration, methodSymbol, context.SemanticModel, context.CancellationToken))
@@ -331,19 +340,21 @@ private static void Analyze(SyntaxNodeAnalysisContext context, in ParameterInfo
         }
     }
 
-    private static void FindUnusedNodes(in ParameterInfo parameterInfo, UnusedParameterWalker walker)
+    private static void FindUnusedNodes(in ParameterInfo parameterInfo, UnusedParameterWalker walker, IMethodSymbol methodSymbol = null)
     {
         if (parameterInfo.Parameter is not null
             && !IsArgListOrDiscard(parameterInfo.Parameter))
         {
-            walker.AddParameter(parameterInfo.Parameter);
+            AddParameter(walker, parameterInfo.Parameter, 0, methodSymbol);
         }
         else
         {
-            foreach (ParameterSyntax parameter in parameterInfo.Parameters)
+            for (int i = 0; i < parameterInfo.Parameters.Count; i++)
             {
+                ParameterSyntax parameter = parameterInfo.Parameters[i];
+
                 if (!IsArgListOrDiscard(parameter))
-                    walker.AddParameter(parameter);
+                    AddParameter(walker, parameter, i, methodSymbol);
             }
         }
 
@@ -357,6 +368,26 @@ private static void FindUnusedNodes(in ParameterInfo parameterInfo, UnusedParame
             walker.Visit(parameterInfo.Node);
     }
 
+    private static void AddParameter(UnusedParameterWalker walker, ParameterSyntax parameter, int index, IMethodSymbol methodSymbol)
+    {
+        if (methodSymbol is not null)
+        {
+            if (index >= methodSymbol.Parameters.Length)
+            {
+                Debug.Fail($"{index} {methodSymbol.Parameters.Length}");
+                return;
+            }
+
+            if (methodSymbol.Parameters[index].Type.HasMetadataName(MetadataNames.System_Runtime_Serialization_StreamingContext)
+                && _attributes.ContainsAny(methodSymbol.GetAttributes()))
+            {
+                return;
+            }
+        }
+
+        walker.AddParameter(parameter);
+    }
+
     private static bool IsArgListOrDiscard(ParameterSyntax parameter)
     {
         return parameter.Identifier.IsKind(SyntaxKind.ArgListKeyword)

src/Workspaces.Core/MetadataNameSet.cs → src/Core/MetadataNameSet.cs

@@ -44,4 +44,18 @@ public bool Contains(ISymbol symbol)
 
         return false;
     }
+
+    public bool ContainsAny(ImmutableArray<AttributeData> attributes)
+    {
+        foreach (AttributeData attributeData in attributes)
+        {
+            if (attributeData.AttributeClass is not null
+                && Contains(attributeData.AttributeClass))
+            {
+                return true;
+            }
+        }
+
+        return false;
+    }
 }

src/Tests/Analyzers.Tests/RCS1163UnusedParameterTests.cs

@@ -234,6 +234,41 @@ namespace System.Windows
     public class DependencyPropertyChangedEventArgs
     {
     }
+}
+ ");
+    }
+
+    [Fact, Trait(Traits.Analyzer, DiagnosticIdentifiers.UnusedParameter)]
+    public async Task TestNoDiagnostic_StreamingContextAttributes()
+    {
+        await VerifyNoDiagnosticAsync(@"
+using System;
+using System.Runtime.Serialization;
+
+class C
+{
+    [Obsolete]
+    [OnSerialized]
+    void M1(string p, StreamingContext context)
+    {
+        var x = p;
+    }
+
+    [OnDeserialized]
+    void M2(StreamingContext context, string p)
+    {
+        var x = p;
+    }
+
+    [OnSerializing]
+    void M3(StreamingContext context)
+    {
+    }
+
+    [OnDeserializing]
+    void M4(StreamingContext context)
+    {
+    }
 }
  ");
     }