Implemented issue provider for CS0127: A method with a void return

type cannot return a value.
This issue provider got requested - and I need to start somewhere to
implement semantic error issue providers.

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

@@ -514,6 +514,7 @@
     <Compile Include="Resolver\AliasNamespaceResolveResult.cs" />
     <Compile Include="Resolver\ReducedExtensionMethod.cs" />
     <Compile Include="Refactoring\CodeIssues\SimplifyAnonymousMethodToDelegateIssue.cs" />
+    <Compile Include="Refactoring\CodeIssues\CompilerErrors\CS0127ReturnMustNotBeFollowedByAnyExpression.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\ICSharpCode.NRefactory\ICSharpCode.NRefactory.csproj">
@@ -529,6 +530,7 @@
     <Folder Include="Refactoring\CodeActions\ExtractMethod\" />
     <Folder Include="Refactoring\CodeActions\ConvertToInitializer\" />
     <Folder Include="Refactoring\CodeIssues\FormatStringIssues\" />
+    <Folder Include="Refactoring\CodeIssues\CompilerErrors\" />
   </ItemGroup>
   <ProjectExtensions>
     <MonoDevelop>

ICSharpCode.NRefactory.CSharp/Refactoring/CodeIssues/CompilerErrors/CS0127ReturnMustNotBeFollowedByAnyExpression.cs

@@ -0,0 +1,96 @@
+//
+// CS0127ReturnMustNotBeFollowedByAnyExpression.cs
+//
+// Author:
+//       Mike Krüger <mkrueger@xamarin.com>
+//
+// Copyright (c) 2013 Xamarin Inc. (http://xamarin.com)
+//
+// 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 System.Collections.Generic;
+using System.Linq;
+using ICSharpCode.NRefactory.PatternMatching;
+
+namespace ICSharpCode.NRefactory.CSharp.Refactoring
+{
+	[IssueDescription("CS0127: A method with a void return type cannot return a value.",
+	                  Description = "Since 'function' returns void, a return keyword must not be followed by an object expression",
+	                  Category = IssueCategories.CompilerErrors,
+	                  Severity = Severity.Error)]
+	public class CS0127ReturnMustNotBeFollowedByAnyExpression : ICodeIssueProvider
+	{
+		public IEnumerable<CodeIssue> GetIssues(BaseRefactoringContext context)
+		{
+			return new GatherVisitor(context).GetIssues();
+		}
+
+		class GatherVisitor : GatherVisitorBase
+		{
+			MethodDeclaration currentMethod;
+
+			public GatherVisitor (BaseRefactoringContext ctx) : base (ctx)
+			{
+			}
+			
+			public override void VisitMethodDeclaration(MethodDeclaration methodDeclaration)
+			{
+				var primitiveType = methodDeclaration.ReturnType as PrimitiveType;
+				if (primitiveType == null || primitiveType.Keyword != "void")
+					return;
+				currentMethod = methodDeclaration;
+				base.VisitMethodDeclaration(methodDeclaration);
+			}
+
+			public override void VisitPropertyDeclaration(PropertyDeclaration propertyDeclaration)
+			{
+			}
+
+			public override void VisitIndexerDeclaration(IndexerDeclaration indexerDeclaration)
+			{
+			}
+
+			public override void VisitCustomEventDeclaration(CustomEventDeclaration eventDeclaration)
+			{
+			}
+
+			public override void VisitLambdaExpression(LambdaExpression lambdaExpression)
+			{
+			}
+
+			public override void VisitAnonymousMethodExpression(AnonymousMethodExpression anonymousMethodExpression)
+			{
+			}
+
+			public override void VisitReturnStatement(ReturnStatement returnStatement)
+			{
+				if (!returnStatement.Expression.IsNull) {
+					AddIssue(
+						returnStatement, 
+						ctx.TranslateString("Remove returned expression"),
+						script => {
+							script.Remove(returnStatement.Expression); 
+						}
+					);
+				}
+			}
+		}
+	}
+}
+

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

@@ -46,7 +46,7 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 			public GatherVisitor (BaseRefactoringContext ctx) : base (ctx)
 			{
 			}
-
+			
 			static Pattern pattern = new Choice {
 				new BlockStatement {
 					new ReturnStatement (new AnyNode ("invoke")) 

ICSharpCode.NRefactory.Tests/CSharp/CodeIssues/CS0127ReturnMustNotBeFollowedByAnyExpressionTests.cs

@@ -0,0 +1,149 @@
+//
+// CS0127ReturnMustNotBeFollowedByAnyExpressionTests.cs
+//
+// Author:
+//       Mike Krüger <mkrueger@xamarin.com>
+//
+// Copyright (c) 2013 Xamarin Inc. (http://xamarin.com)
+//
+// 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.Refactoring;
+using ICSharpCode.NRefactory.CSharp.CodeActions;
+
+namespace ICSharpCode.NRefactory.CSharp.CodeIssues
+{
+	[TestFixture]
+	public class CS0127ReturnMustNotBeFollowedByAnyExpressionTests : InspectionActionTestBase
+	{
+		[Test]
+		public void TestSimpleCase ()
+		{
+			var input = @"class Foo
+{
+	void Bar (string str)
+	{
+		return str;
+	}
+}";
+			
+			TestRefactoringContext context;
+			var issues = GetIssues (new CS0127ReturnMustNotBeFollowedByAnyExpression (), input, out context);
+			Assert.AreEqual (1, issues.Count);
+			CheckFix (context, issues, @"class Foo
+{
+	void Bar (string str)
+	{
+		return ;
+	}
+}");
+		}
+		
+		[Test]
+		public void TestSimpleInvalidCase ()
+		{
+			var input = @"class Foo
+{
+	string Bar (string str)
+	{
+		return str;
+	}
+}";
+			
+			TestRefactoringContext context;
+			var issues = GetIssues (new CS0127ReturnMustNotBeFollowedByAnyExpression (), input, out context);
+			Assert.AreEqual (0, issues.Count);
+		}
+
+		[Test]
+		public void TestProperty ()
+		{
+			var input = @"class Foo {
+	string Bar 
+	{
+		get {
+			return ""Hello World "";
+		}
+	}
+}";
+			
+			TestRefactoringContext context;
+			var issues = GetIssues (new CS0127ReturnMustNotBeFollowedByAnyExpression (), input, out context);
+			Assert.AreEqual (0, issues.Count);
+		}
+
+		[Test]
+		public void TestIndexer ()
+		{
+			var input = @"class Foo {
+	string this [int idx]
+	{
+		get {
+			return ""Hello World "";
+		}
+	}
+}";
+			
+			TestRefactoringContext context;
+			var issues = GetIssues (new CS0127ReturnMustNotBeFollowedByAnyExpression (), input, out context);
+			Assert.AreEqual (0, issues.Count);
+		}
+
+		[Test]
+		public void TestAnonymousMethod ()
+		{
+			var input = @"class Foo
+{
+	void Bar (string str)
+	{
+		System.Func<string> func = delegate {
+			return str;
+		};
+	}
+}";
+			
+			TestRefactoringContext context;
+			var issues = GetIssues (new CS0127ReturnMustNotBeFollowedByAnyExpression (), input, out context);
+			Assert.AreEqual (0, issues.Count);
+		}
+		
+		[Test]
+		public void TestLambdaMethod ()
+		{
+			var input = @"class Foo
+{
+	void Bar (string str)
+	{
+		System.Func<string> func = () => {
+			return str;
+		};
+	}
+}";
+			
+			TestRefactoringContext context;
+			var issues = GetIssues (new CS0127ReturnMustNotBeFollowedByAnyExpression (), input, out context);
+			Assert.AreEqual (0, issues.Count);
+		}
+		
+
+
+	}
+}
+

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

@@ -392,6 +392,7 @@
     <Compile Include="CSharp\CodeActions\CreateEnumValueTests.cs" />
     <Compile Include="CSharp\CodeCompletion\GetCurrentParameterIndexTests.cs" />
     <Compile Include="CSharp\CodeIssues\SimplifyAnonymousMethodToDelegateIssueTests.cs" />
+    <Compile Include="CSharp\CodeIssues\CS0127ReturnMustNotBeFollowedByAnyExpressionTests.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\..\cecil\Mono.Cecil.csproj">