[CodeIssue] Added MethodNeverReturnsIssue

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

@@ -293,6 +293,7 @@
     <Compile Include="Refactoring\CodeIssues\DoubleNegationIssue.cs" />
     <Compile Include="Refactoring\CodeIssues\ExpressionIsAlwaysOfProvidedTypeIssue.cs" />
     <Compile Include="Refactoring\CodeIssues\ExpressionIsNeverOfProvidedTypeIssue.cs" />
+    <Compile Include="Refactoring\CodeIssues\MethodNeverReturnsIssue.cs" />
     <Compile Include="Refactoring\CodeIssues\NegativeRelationalExpressionIssue.cs" />
     <Compile Include="Refactoring\CodeIssues\ExplicitConversionInForEachIssue.cs" />
     <Compile Include="Refactoring\CodeIssues\ForControlVariableNotModifiedIssue.cs" />

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

@@ -0,0 +1,87 @@
+// 
+// MethodNeverReturnsIssue.cs
+// 
+// Author:
+//      Mansheng Yang <lightyang0@gmail.com>
+// 
+// Copyright (c) 2012 Mansheng Yang <lightyang0@gmail.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.Collections.Generic;
+using ICSharpCode.NRefactory.CSharp.Analysis;
+
+namespace ICSharpCode.NRefactory.CSharp.Refactoring
+{
+	[IssueDescription ("Method never returns",
+		Description = "Method does not reach its end or a 'return' statement by any of possible execution paths.",
+		Category = IssueCategories.CodeQualityIssues,
+		Severity = Severity.Warning,
+		IssueMarker = IssueMarker.Underline)]
+	public class MethodNeverReturnsIssue : ICodeIssueProvider
+	{
+		public IEnumerable<CodeIssue> GetIssues (BaseRefactoringContext context)
+		{
+			return new GatherVisitor (context).GetIssues ();
+		}
+
+		class GatherVisitor : GatherVisitorBase
+		{
+			static readonly ControlFlowGraphBuilder cfgBuilder = new ControlFlowGraphBuilder ();
+
+			public GatherVisitor(BaseRefactoringContext ctx)
+				: base (ctx)
+			{
+			}
+
+			public override void VisitMethodDeclaration (MethodDeclaration methodDeclaration)
+			{
+				base.VisitMethodDeclaration (methodDeclaration);
+
+				// partial method
+				if (methodDeclaration.Body.IsNull)
+					return;
+
+				var cfg = cfgBuilder.BuildControlFlowGraph (methodDeclaration.Body, ctx.Resolver,
+					ctx.CancellationToken);
+				var stack = new Stack<ControlFlowNode> ();
+				var visitedNodes = new HashSet<ControlFlowNode> ();
+				stack.Push (cfg [0]);
+				while (stack.Count > 0) {
+					var node = stack.Pop ();
+
+					// reach method's end
+					if (node.PreviousStatement == methodDeclaration.Body)
+						return;
+					// reach a return statement
+					if (node.NextStatement is ReturnStatement)
+						return;
+
+					foreach (var edge in node.Outgoing) {
+						if (visitedNodes.Add(edge.To))
+							stack.Push(edge.To);
+					}
+				}
+
+				AddIssue (methodDeclaration.NameToken, 
+					ctx.TranslateString ("Method never reaches its end or a 'return' statement."));
+			}
+		}
+	}
+}

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

@@ -0,0 +1,77 @@
+// 
+// MethodNeverReturnsIssueTests.cs
+// 
+// Author:
+//      Mansheng Yang <lightyang0@gmail.com>
+// 
+// Copyright (c) 2012 Mansheng Yang <lightyang0@gmail.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 ICSharpCode.NRefactory.CSharp.Refactoring;
+using NUnit.Framework;
+
+namespace ICSharpCode.NRefactory.CSharp.CodeIssues
+{
+	[TestFixture]
+	public class MethodNeverReturnsIssueTests : InspectionActionTestBase
+	{
+		[Test]
+		public void TestEnd ()
+		{
+			var input = @"
+partial class TestClass
+{
+	void TestMethod () 
+	{
+		int i = 1;
+	}
+}";
+			Test<MethodNeverReturnsIssue> (input, 0);
+		}
+
+		[Test]
+		public void TestReturn ()
+		{
+			var input = @"
+partial class TestClass
+{
+	void TestMethod ()
+	{
+		return;
+	}
+}";
+			Test<MethodNeverReturnsIssue> (input, 0);
+		}
+
+		[Test]
+		public void Test ()
+		{
+			var input = @"
+partial class TestClass
+{
+	void TestMethod ()
+	{
+		while (true) ;
+	}
+}";
+			Test<MethodNeverReturnsIssue> (input, 1);
+		}
+	}
+}

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

@@ -158,6 +158,7 @@
     <Compile Include="CSharp\CodeIssues\LocalVariableHidesMemberIssueTests.cs" />
     <Compile Include="CSharp\CodeIssues\LocalVariableNotUsedIssueTests.cs" />
     <Compile Include="CSharp\CodeIssues\LocalVariableOnlyAssignedIssueTests.cs" />
+    <Compile Include="CSharp\CodeIssues\MethodNeverReturnsIssueTests.cs" />
     <Compile Include="CSharp\CodeIssues\MultipleEnumerationIssueTests.cs" />
     <Compile Include="CSharp\CodeIssues\NegativeRelationalExpressionIssueTests.cs" />
     <Compile Include="CSharp\CodeIssues\ParameterHidesMemberIssueTests.cs" />