Add PreferNonGenericVariantFor attribute and analyzer

Robust.Analyzers.Tests/PreferNonGenericVariantForTest.cs

@@ -0,0 +1,71 @@
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.CSharp.Testing;
+using Microsoft.CodeAnalysis.Testing;
+using Microsoft.CodeAnalysis.Testing.Verifiers;
+using NUnit.Framework;
+using VerifyCS =
+    Microsoft.CodeAnalysis.CSharp.Testing.NUnit.AnalyzerVerifier<Robust.Analyzers.PreferNonGenericVariantForAnalyzer>;
+
+namespace Robust.Analyzers.Tests;
+
+[Parallelizable(ParallelScope.All | ParallelScope.Fixtures)]
+[TestFixture]
+public sealed class PreferNonGenericVariantForTest
+{
+    private static Task Verifier(string code, params DiagnosticResult[] expected)
+    {
+        var test = new CSharpAnalyzerTest<PreferNonGenericVariantForAnalyzer, NUnitVerifier>()
+        {
+            TestState =
+            {
+                Sources = { code },
+            },
+        };
+
+        TestHelper.AddEmbeddedSources(
+            test.TestState,
+            "Robust.Shared.Analyzers.PreferNonGenericVariantForAttribute.cs"
+        );
+
+        // ExpectedDiagnostics cannot be set, so we need to AddRange here...
+        test.TestState.ExpectedDiagnostics.AddRange(expected);
+
+        return test.RunAsync();
+    }
+
+    [Test]
+    public async Task Test()
+    {
+        const string code = """
+            using Robust.Shared.Analyzers;
+
+            public class Bar { };
+            public class Baz { };
+            public class Okay { };
+
+            public static class Foo
+            {
+                [PreferNonGenericVariantFor(typeof(Bar), typeof(Baz))]
+                public static void DoFoo<T>() { }
+            }
+
+            public class Test
+            {
+                public void DoBad()
+                {
+                    Foo.DoFoo<Bar>();
+                }
+
+                public void DoGood()
+                {
+                    Foo.DoFoo<Okay>();
+                }
+            }
+            """;
+
+        await Verifier(code,
+            // /0/Test0.cs(17,9): warning RA0029: Use the non-generic variant of this method for type Bar
+            VerifyCS.Diagnostic().WithSpan(17, 9, 17, 25).WithArguments("Bar")
+        );
+    }
+}

Robust.Analyzers.Tests/Robust.Analyzers.Tests.csproj

@@ -10,6 +10,7 @@
   <ItemGroup>
     <EmbeddedResource Include="..\Robust.Shared\Analyzers\AccessAttribute.cs" LogicalName="Robust.Shared.Analyzers.AccessAttribute.cs" LinkBase="Implementations" />
     <EmbeddedResource Include="..\Robust.Shared\Analyzers\AccessPermissions.cs" LogicalName="Robust.Shared.Analyzers.AccessPermissions.cs" LinkBase="Implementations" />
+    <EmbeddedResource Include="..\Robust.Shared\Analyzers\PreferNonGenericVariantForAttribute.cs" LogicalName="Robust.Shared.Analyzers.PreferNonGenericVariantForAttribute.cs" LinkBase="Implementations" />
     <EmbeddedResource Include="..\Robust.Shared\IoC\DependencyAttribute.cs" LogicalName="Robust.Shared.IoC.DependencyAttribute.cs" LinkBase="Implementations" />
   </ItemGroup>
 

Robust.Analyzers/PreferNonGenericVariantForAnalyzer.cs

@@ -0,0 +1,65 @@
+using System.Collections.Immutable;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.Diagnostics;
+using Microsoft.CodeAnalysis.Operations;
+using Robust.Roslyn.Shared;
+
+namespace Robust.Analyzers;
+
+[DiagnosticAnalyzer(LanguageNames.CSharp)]
+public sealed class PreferNonGenericVariantForAnalyzer : DiagnosticAnalyzer
+{
+    private const string AttributeType = "Robust.Shared.Analyzers.PreferNonGenericVariantForAttribute";
+
+    public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => ImmutableArray.Create(
+        UseNonGenericVariantDescriptor
+    );
+
+    private static readonly DiagnosticDescriptor UseNonGenericVariantDescriptor = new(
+        Diagnostics.IdUseNonGenericVariant,
+        "Consider using the non-generic variant of this method",
+        "Use the non-generic variant of this method for type {0}",
+        "Usage",
+        DiagnosticSeverity.Warning,
+        true,
+        "Use the generic variant of this method.");
+
+    public override void Initialize(AnalysisContext context)
+    {
+        context.ConfigureGeneratedCodeAnalysis(GeneratedCodeAnalysisFlags.ReportDiagnostics | GeneratedCodeAnalysisFlags.Analyze);
+        context.EnableConcurrentExecution();
+        context.RegisterOperationAction(CheckForNonGenericVariant, OperationKind.Invocation);
+    }
+
+    private void CheckForNonGenericVariant(OperationAnalysisContext obj)
+    {
+        if (obj.Operation is not IInvocationOperation invocationOperation) return;
+
+        var preferNonGenericAttribute = obj.Compilation.GetTypeByMetadataName(AttributeType);
+
+        HashSet<ITypeSymbol> forTypes = [];
+        foreach (var attribute in invocationOperation.TargetMethod.GetAttributes())
+        {
+            if (!SymbolEqualityComparer.Default.Equals(attribute.AttributeClass, preferNonGenericAttribute))
+                continue;
+
+            foreach (var type in attribute.ConstructorArguments[0].Values)
+                forTypes.Add((ITypeSymbol)type.Value);
+
+            break;
+        }
+
+        if (forTypes == null)
+            return;
+
+        foreach (var typeArg in invocationOperation.TargetMethod.TypeArguments)
+        {
+            if (forTypes.Contains(typeArg))
+            {
+                obj.ReportDiagnostic(
+                Diagnostic.Create(UseNonGenericVariantDescriptor,
+                    invocationOperation.Syntax.GetLocation(), typeArg.Name));
+            }
+        }
+    }
+}

Robust.Analyzers/Robust.Analyzers.csproj

@@ -16,6 +16,11 @@
     <Compile Include="..\Robust.Shared\Analyzers\PreferGenericVariantAttribute.cs" LinkBase="Implementations" />
   </ItemGroup>
 
+  <ItemGroup>
+    <!-- Needed for PreferNonGenericVariantAnalyzer. -->
+    <Compile Include="..\Robust.Shared\Analyzers\PreferNonGenericVariantForAttribute.cs" LinkBase="Implementations" />
+  </ItemGroup>
+
   <ItemGroup>
     <!-- Needed for DataDefinitionAnalyzer. -->
     <Compile Include="..\Robust.Shared\Serialization\Manager\Definition\DataDefinitionUtility.cs" LinkBase="Implementations" />

Robust.Roslyn.Shared/Diagnostics.cs

@@ -31,6 +31,7 @@ public static class Diagnostics
     public const string IdDependencyFieldAssigned = "RA0025";
     public const string IdUncachedRegex = "RA0026";
     public const string IdDataFieldRedundantTag = "RA0027";
+    public const string IdUseNonGenericVariant = "RA0029";
 
     public static SuppressionDescriptor MeansImplicitAssignment =>
         new SuppressionDescriptor("RADC1000", "CS0649", "Marked as implicitly assigned.");

Robust.Shared/Analyzers/PreferNonGenericVariantForAttribute.cs

@@ -0,0 +1,18 @@
+using System;
+
+#if ROBUST_ANALYZERS_IMPL
+namespace Robust.Shared.Analyzers.Implementation;
+#else
+namespace Robust.Shared.Analyzers;
+#endif
+
+[AttributeUsage(AttributeTargets.Method)]
+public sealed class PreferNonGenericVariantForAttribute : Attribute
+{
+    public readonly Type[] ForTypes;
+
+    public PreferNonGenericVariantForAttribute(params Type[] forTypes)
+    {
+        ForTypes = forTypes;
+    }
+}

Robust.Shared/GameObjects/EntitySystem.Proxy.cs

@@ -431,6 +431,7 @@ protected EntityStringRepresentation ToPrettyString(NetEntity netEntity)
 
     /// <inheritdoc cref="IEntityManager.TryGetComponent&lt;T&gt;(EntityUid, out T)"/>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    [PreferNonGenericVariantFor(typeof(TransformComponent), typeof(MetaDataComponent))]
     protected bool TryComp<T>(EntityUid uid, [NotNullWhen(true)] out T? comp) where T : IComponent
     {
         return EntityManager.TryGetComponent(uid, out comp);