[CodeIssues] Add IncorrectCalltoGetHashCodeIssue.

ICSharpCode.NRefactory.CSharp/ICSharpCode.NRefactory.CSharp.csproj

@@ -401,6 +401,7 @@
     <Compile Include="Refactoring\CodeIssues\RedundantCatchIssue.cs" />
     <Compile Include="Refactoring\CodeIssues\RedundantToStringIssue.cs" />
     <Compile Include="Refactoring\CodeIssues\CallToObjectEqualsViaBaseIssue.cs" />
+    <Compile Include="Refactoring\CodeIssues\IncorrectCallToObjectGetHashCodeIssue.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\ICSharpCode.NRefactory\ICSharpCode.NRefactory.csproj">

ICSharpCode.NRefactory.CSharp/Refactoring/CodeIssues/IncorrectCallToObjectGetHashCodeIssue.cs

@@ -0,0 +1,90 @@
+//
+// IncorrectCallToObjectGetHashCodeIssue.cs
+//
+// Author:
+//       Simon Lindgren <simon.n.lindgren@gmail.com>
+//
+// Copyright (c) 2012 Simon Lindgren
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+using System.Collections.Generic;
+using ICSharpCode.NRefactory.TypeSystem;
+using ICSharpCode.NRefactory.Semantics;
+
+namespace ICSharpCode.NRefactory.CSharp.Refactoring
+{
+	[IssueDescription("Call resolves to Object.GetHashCode, which is reference based",
+	                   Description = "Finds calls to Object.GetHashCode inside overridden GetHashCode.",
+	                   Category = IssueCategories.CodeQualityIssues,
+	                   Severity = Severity.Warning)]
+	public class IncorrectCallToObjectGetHashCodeIssue : ICodeIssueProvider
+	{
+		public IEnumerable<CodeIssue> GetIssues(BaseRefactoringContext context)
+		{
+			return new GatherVisitor(context).GetIssues();
+		}
+		
+		class GatherVisitor : GatherVisitorBase
+		{
+			IType objectType;
+			
+			public GatherVisitor(BaseRefactoringContext context) : base (context)
+			{				
+				objectType = context.Compilation.FindType(KnownTypeCode.Object);
+			}
+
+			public override void VisitMethodDeclaration(MethodDeclaration methodDeclaration)
+			{
+				// Check that this declaration is a GetHashCode override, _then_ recurse
+
+				if (methodDeclaration.Name != "GetHashCode") {
+					return;
+				}
+				if (!methodDeclaration.Modifiers.HasFlag(Modifiers.Override)) {
+					return;
+				}
+
+				base.VisitMethodDeclaration(methodDeclaration);
+			}
+
+			public override void VisitInvocationExpression(InvocationExpression invocationExpression)
+			{
+				base.VisitInvocationExpression(invocationExpression);
+
+				if (invocationExpression.Arguments.Count != 0) {
+					return;
+				}
+				var memberReference = invocationExpression.Target as MemberReferenceExpression;
+				if (memberReference == null) {
+					return;
+				}
+				var targetedObject = memberReference.Target as BaseReferenceExpression;
+				if (targetedObject == null) {
+					return;
+				}
+				var resolveResult = ctx.Resolve(targetedObject) as ThisResolveResult;
+				if (resolveResult == null || resolveResult.Type != objectType) {
+					return;
+				}
+				AddIssue(invocationExpression, ctx.TranslateString("Call resolves to Object.GetHashCode, which is reference based"));
+			}
+		}
+	}
+}
+

ICSharpCode.NRefactory.Tests/CSharp/CodeIssues/IncorrectCallToGetHashCodeTests.cs

@@ -0,0 +1,69 @@
+//
+// IncorrectCallToGetHashCodeTests.cs
+//
+// Author:
+//       Simon Lindgren <simon.n.lindgren@gmail.com>
+//
+// Copyright (c) 2012 Simon Lindgren
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+using System;
+using NUnit.Framework;
+using ICSharpCode.NRefactory.CSharp.CodeActions;
+using ICSharpCode.NRefactory.CSharp.Refactoring;
+
+namespace ICSharpCode.NRefactory.CSharp.CodeIssues
+{
+	[TestFixture]
+	public class IncorrectCallToGetHashCodeTests : InspectionActionTestBase
+	{
+		[Test]
+		public void SimpleCase()
+		{
+			var input = @"
+class Foo
+{
+	public override int GetHashCode()
+	{
+		return base.GetHashCode();
+	}
+}";
+			TestRefactoringContext context;
+			var issues = GetIssues(new IncorrectCallToObjectGetHashCodeIssue(), input, out context);
+			Assert.AreEqual(1, issues.Count);
+		}
+
+		[Test]
+		public void DoesNotCheckOutsideOverriddenGetHashCode()
+		{
+			var input = @"
+class Foo
+{
+	public void Bar()
+	{
+		return base.GetHashCode();
+	}
+}";
+			TestRefactoringContext context;
+			var issues = GetIssues(new IncorrectCallToObjectGetHashCodeIssue(), input, out context);
+			Assert.AreEqual(0, issues.Count);
+		}
+	}
+}
+

ICSharpCode.NRefactory.Tests/ICSharpCode.NRefactory.Tests.csproj

@@ -296,6 +296,7 @@
     <Compile Include="CSharp\CodeIssues\RedundantCatchTests.cs" />
     <Compile Include="CSharp\CodeIssues\RedundantToStringTests.cs" />
     <Compile Include="CSharp\CodeIssues\CallToObjectEqualsViaBaseTests.cs" />
+    <Compile Include="CSharp\CodeIssues\IncorrectCallToGetHashCodeTests.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\..\Mono.Cecil\Mono.Cecil.csproj">