diff --git a/ICSharpCode.NRefactory.CSharp/ICSharpCode.NRefactory.CSharp.csproj b/ICSharpCode.NRefactory.CSharp/ICSharpCode.NRefactory.CSharp.csproj
index 7a7d7ef576..a0dce4bea3 100644
--- a/ICSharpCode.NRefactory.CSharp/ICSharpCode.NRefactory.CSharp.csproj
+++ b/ICSharpCode.NRefactory.CSharp/ICSharpCode.NRefactory.CSharp.csproj
@@ -261,6 +261,7 @@
+
diff --git a/ICSharpCode.NRefactory.CSharp/Refactoring/CodeIssues/BitwiseOperationOnNonFlagsEnumIssue.cs b/ICSharpCode.NRefactory.CSharp/Refactoring/CodeIssues/BitwiseOperationOnNonFlagsEnumIssue.cs
new file mode 100644
index 0000000000..72d0d1e455
--- /dev/null
+++ b/ICSharpCode.NRefactory.CSharp/Refactoring/CodeIssues/BitwiseOperationOnNonFlagsEnumIssue.cs
@@ -0,0 +1,119 @@
+//
+// BitwiseOperationOnNonFlagsEnumIssue.cs
+//
+// Author:
+// Mansheng Yang
+//
+// Copyright (c) 2012 Mansheng Yang
+//
+// 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 System.Linq;
+using ICSharpCode.NRefactory.TypeSystem;
+
+namespace ICSharpCode.NRefactory.CSharp.Refactoring
+{
+ [IssueDescription ("Bitwise Operations on enum without [Flags] attribute",
+ Description = "Bitwise Operations on enum not marked with [Flags] attribute",
+ Category = IssueCategories.CodeQualityIssues,
+ Severity = Severity.Warning,
+ IssueMarker = IssueMarker.Underline)]
+ public class BitwiseOperationOnNonFlagsEnumIssue : ICodeIssueProvider
+ {
+ public IEnumerable GetIssues (BaseRefactoringContext context)
+ {
+ return new GatherVisitor (context).GetIssues ();
+ }
+
+ class GatherVisitor : GatherVisitorBase
+ {
+ public GatherVisitor (BaseRefactoringContext ctx)
+ : base(ctx)
+ {
+ }
+
+ static bool IsBitwiseOperator (UnaryOperatorType op)
+ {
+ return op == UnaryOperatorType.BitNot;
+ }
+
+ static bool IsBitwiseOperator (AssignmentOperatorType op)
+ {
+ return op == AssignmentOperatorType.BitwiseAnd || op == AssignmentOperatorType.BitwiseOr ||
+ op == AssignmentOperatorType.ExclusiveOr;
+ }
+
+ static bool IsBitwiseOperator (BinaryOperatorType op)
+ {
+ return op == BinaryOperatorType.BitwiseAnd || op == BinaryOperatorType.BitwiseOr ||
+ op == BinaryOperatorType.ExclusiveOr;
+ }
+
+ bool IsNonFlagsEnum (Expression expr)
+ {
+ var resolveResult = ctx.Resolve (expr);
+ if (resolveResult == null || resolveResult.Type.Kind != TypeKind.Enum)
+ return false;
+
+ // check [Flags]
+ var typeDef = resolveResult.Type.GetDefinition ();
+ return typeDef != null &&
+ typeDef.Attributes.All (attr => attr.AttributeType.FullName != "System.FlagsAttribute");
+ }
+
+ private void AddIssue (CSharpTokenNode operatorToken)
+ {
+ AddIssue (operatorToken,
+ ctx.TranslateString ("Bitwise Operations on enum not marked with Flags attribute"));
+ }
+
+ public override void VisitUnaryOperatorExpression (UnaryOperatorExpression unaryOperatorExpression)
+ {
+ base.VisitUnaryOperatorExpression (unaryOperatorExpression);
+
+ if (!IsBitwiseOperator (unaryOperatorExpression.Operator))
+ return;
+ if (IsNonFlagsEnum (unaryOperatorExpression.Expression))
+ AddIssue (unaryOperatorExpression.OperatorToken);
+ }
+
+ public override void VisitAssignmentExpression (AssignmentExpression assignmentExpression)
+ {
+ base.VisitAssignmentExpression (assignmentExpression);
+
+ if (!IsBitwiseOperator (assignmentExpression.Operator))
+ return;
+ if (IsNonFlagsEnum (assignmentExpression.Right))
+ AddIssue (assignmentExpression.OperatorToken);
+ }
+
+ public override void VisitBinaryOperatorExpression (BinaryOperatorExpression binaryOperatorExpression)
+ {
+ base.VisitBinaryOperatorExpression (binaryOperatorExpression);
+
+ if (!IsBitwiseOperator (binaryOperatorExpression.Operator))
+ return;
+ if (IsNonFlagsEnum (binaryOperatorExpression.Left) || IsNonFlagsEnum (binaryOperatorExpression.Right))
+ AddIssue (binaryOperatorExpression.OperatorToken);
+ }
+
+ }
+ }
+}
diff --git a/ICSharpCode.NRefactory.Tests/CSharp/CodeIssues/BitwiseOperationOnNonFlagsEnumIssueTests.cs b/ICSharpCode.NRefactory.Tests/CSharp/CodeIssues/BitwiseOperationOnNonFlagsEnumIssueTests.cs
new file mode 100644
index 0000000000..66379f2dba
--- /dev/null
+++ b/ICSharpCode.NRefactory.Tests/CSharp/CodeIssues/BitwiseOperationOnNonFlagsEnumIssueTests.cs
@@ -0,0 +1,105 @@
+//
+// BitwiseOperationOnNonFlagsEnumIssueTests.cs
+//
+// Author:
+// Mansheng Yang
+//
+// Copyright (c) 2012 Mansheng Yang
+//
+// 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 BitwiseOperationOnNonFlagsEnumIssueTests : InspectionActionTestBase
+ {
+ [Test]
+ public void TestUnary ()
+ {
+ var input = @"
+enum TestEnum
+{
+ Item1, Item2
+}
+class TestClass
+{
+ void TestMethod ()
+ {
+ var x = ~TestEnum.Item1;
+ }
+}";
+ Test (input, 1);
+ }
+
+ public void TestAssignment (string op, bool bitwise = true)
+ {
+ var input = @"
+enum TestEnum
+{
+ Item1, Item2
+}
+class TestClass
+{
+ void TestMethod ()
+ {
+ var x = TestEnum.Item1;
+ x " + op + @"= TestEnum.Item2;
+ }
+}";
+ Test (input, bitwise ? 1: 0);
+ }
+ [Test]
+ public void TestAssignment ()
+ {
+ TestAssignment ("|");
+ TestAssignment ("&");
+ TestAssignment ("^");
+ TestAssignment ("+", false);
+ }
+
+ public void TestBinary (string op, bool bitwise = true)
+ {
+
+ var input = @"
+enum TestEnum
+{
+ Item1, Item2
+}
+class TestClass
+{
+ void TestMethod ()
+ {
+ var x = TestEnum.Item1 " + op + @" TestEnum.Item2;
+ }
+}";
+ Test (input, bitwise ? 1 : 0);
+ }
+ [Test]
+ public void TestBinary()
+ {
+ TestBinary ("&");
+ TestBinary ("|");
+ TestBinary ("^");
+ TestBinary ("+", false);
+ }
+ }
+}
diff --git a/ICSharpCode.NRefactory.Tests/ICSharpCode.NRefactory.Tests.csproj b/ICSharpCode.NRefactory.Tests/ICSharpCode.NRefactory.Tests.csproj
index d2ab30666f..6142c942c7 100644
--- a/ICSharpCode.NRefactory.Tests/ICSharpCode.NRefactory.Tests.csproj
+++ b/ICSharpCode.NRefactory.Tests/ICSharpCode.NRefactory.Tests.csproj
@@ -100,6 +100,7 @@
+