[CodeIssue] Added ForControlVariableNotModifiedIssue

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

@@ -262,6 +262,7 @@
     <Compile Include="Refactoring\CodeIssues\AccessToClosureIssues\AccessToModifiedClosureIssue.cs" />
     <Compile Include="Refactoring\CodeIssues\AccessToClosureIssues\LocalVariableNamePicker.cs" />
     <Compile Include="Refactoring\CodeIssues\ExplicitConversionInForEachIssue.cs" />
+    <Compile Include="Refactoring\CodeIssues\ForControlVariableNotModifiedIssue.cs" />
     <Compile Include="Refactoring\CodeIssues\RedundantElseIssue.cs" />
     <Compile Include="Refactoring\CodeIssues\RedundantFieldInitializerIssue.cs" />
     <Compile Include="Refactoring\CodeIssues\VariableHidesMemberIssue\LocalVariableHidesMemberIssue.cs" />

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

@@ -0,0 +1,141 @@
+// 
+// ForControlVariableNotModifiedIssue.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 System.Linq;
+using ICSharpCode.NRefactory.CSharp.Resolver;
+using ICSharpCode.NRefactory.PatternMatching;
+using ICSharpCode.NRefactory.Semantics;
+
+namespace ICSharpCode.NRefactory.CSharp.Refactoring
+{
+	[IssueDescription ("'for' loop control variable is never modified",
+					   Description = "'for' loop control variable is never modified.",
+					   Category = IssueCategories.CodeQualityIssues,
+					   Severity = Severity.Warning,
+					   IssueMarker = IssueMarker.Underline)]
+	public class ForControlVariableNotModifiedIssue : ICodeIssueProvider
+	{
+		static FindReferences refFinder = new FindReferences ();
+
+		public IEnumerable<CodeIssue> GetIssues (BaseRefactoringContext context)
+		{
+			var unit = context.RootNode as CompilationUnit;
+			if (unit == null)
+				return Enumerable.Empty<CodeIssue> ();
+
+			return new GatherVisitor (context, unit).GetIssues ();
+		}
+
+		class GatherVisitor : GatherVisitorBase
+		{
+			CompilationUnit unit;
+			public GatherVisitor(BaseRefactoringContext ctx, CompilationUnit unit)
+				: base (ctx)
+			{
+				this.unit = unit;
+			}
+
+			static VariableInitializer GetControlVariable(VariableDeclarationStatement variableDecl, 
+														  BinaryOperatorExpression condition)
+			{
+				var controlVariables = variableDecl.Variables.Where (
+					v =>
+					{
+						var identifier = new IdentifierExpression (v.Name);
+						return condition.Left.Match (identifier).Success ||
+							condition.Right.Match (identifier).Success;
+					}).ToList ();
+				return controlVariables.Count == 1 ? controlVariables [0] : null;
+			}
+
+			static VariableInitializer GetControlVariable(VariableDeclarationStatement variableDecl,
+														  UnaryOperatorExpression condition)
+			{
+				var controlVariables = variableDecl.Variables.Where (
+					v =>
+					{
+						var identifier = new IdentifierExpression (v.Name);
+						return condition.Expression.Match (identifier).Success;
+					}).ToList ();
+				return controlVariables.Count == 1 ? controlVariables [0] : null;
+			}
+
+			public override void VisitForStatement (ForStatement forStatement)
+			{
+				base.VisitForStatement (forStatement);
+
+				if (forStatement.Initializers.Count != 1)
+					return;
+				var variableDecl = forStatement.Initializers.First () as VariableDeclarationStatement;
+				if (variableDecl == null)
+					return;
+
+				VariableInitializer controlVariable = null;
+				if (forStatement.Condition is BinaryOperatorExpression) {
+					controlVariable = GetControlVariable (variableDecl, (BinaryOperatorExpression)forStatement.Condition);
+				} else if (forStatement.Condition is UnaryOperatorExpression) {
+					controlVariable = GetControlVariable (variableDecl, (UnaryOperatorExpression)forStatement.Condition);
+				} else if (forStatement.Condition is IdentifierExpression) {
+					controlVariable = variableDecl.Variables.FirstOrDefault (
+						v => v.Name == ((IdentifierExpression)forStatement.Condition).Identifier);
+				}
+
+				if (controlVariable == null)
+					return;
+
+				var localResolveResult = ctx.Resolve (controlVariable) as LocalResolveResult;
+				if (localResolveResult == null)
+					return;
+
+				var modified = false;
+				refFinder.FindLocalReferences (localResolveResult.Variable, ctx.ParsedFile, unit, ctx.Compilation,
+					(node, resolveResult) =>
+					{
+						if (modified)
+							return;
+
+						var unary = node.Parent as UnaryOperatorExpression;
+						if (unary != null && unary.Expression == node) {
+							modified = unary.Operator == UnaryOperatorType.Decrement ||
+								unary.Operator == UnaryOperatorType.PostDecrement ||
+								unary.Operator == UnaryOperatorType.Increment ||
+								unary.Operator == UnaryOperatorType.PostIncrement;
+							return;
+						}
+
+						var assignment = node.Parent as AssignmentExpression;
+						modified = assignment != null && assignment.Left == node;
+					}, ctx.CancellationToken);
+
+				if (!modified)
+					AddIssue (controlVariable.NameToken,
+						ctx.TranslateString ("'for' loop control variable is never modified"));
+
+			}
+		}
+	}
+}

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

@@ -0,0 +1,133 @@
+// 
+// ForControlVariableNotModifiedIssueTests.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 ForControlVariableNotModifiedIssueTests : InspectionActionTestBase
+	{
+		[Test]
+		public void TestBinaryOpConditionNotModified ()
+		{
+			var input = @"
+class TestClass
+{
+	void TestMethod ()
+	{
+		for (int i = 0, j = 0; i < 10; j++)
+		{
+		}
+	}
+}";
+			Test<ForControlVariableNotModifiedIssue> (input, 1);
+		}
+
+		[Test]
+		public void TestBinaryOpConditionModified ()
+		{
+			var input = @"
+class TestClass
+{
+	void TestMethod ()
+	{
+		for (int i = 0, j = 0; i < 10; i++)
+		{
+		}
+	}
+}";
+			Test<ForControlVariableNotModifiedIssue> (input, 0);
+		}
+
+		[Test]
+		public void TestUnaryOpConditionNotModified ()
+		{
+			var input = @"
+class TestClass
+{
+	void TestMethod ()
+	{
+		for (bool x = true; !x;)
+		{
+		}
+	}
+}";
+			Test<ForControlVariableNotModifiedIssue> (input, 1);
+		}
+
+		[Test]
+		public void TestUnaryOpConditionModified()
+		{
+			var input = @"
+class TestClass
+{
+	void TestMethod ()
+	{
+		for (bool x = true; !x;)
+		{
+			x = false;
+		}
+	}
+}";
+			Test<ForControlVariableNotModifiedIssue> (input, 0);
+		}
+
+		[Test]
+		public void TestIdentifierConditionNotModified ()
+		{
+			var input = @"
+class TestClass
+{
+	void TestMethod ()
+	{
+		for (bool x = true; x;)
+		{
+		}
+	}
+}";
+			Test<ForControlVariableNotModifiedIssue> (input, 1);
+		}
+
+		[Test]
+		public void TestIdentifierConditionModified ()
+		{
+			var input = @"
+class TestClass
+{
+	void TestMethod ()
+	{
+		for (bool x = false; x;)
+		{
+			x = true;
+		}
+	}
+}";
+			Test<ForControlVariableNotModifiedIssue> (input, 0);
+		}
+	}
+}

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

@@ -101,6 +101,7 @@
     <Compile Include="CSharp\CodeIssues\AccessToDisposedClosureTests.cs" />
     <Compile Include="CSharp\CodeIssues\AccessToModifiedClosureTests.cs" />
     <Compile Include="CSharp\CodeIssues\ExplicitConversionInForEachIssueTests.cs" />
+    <Compile Include="CSharp\CodeIssues\ForControlVariableNotModifiedIssueTests.cs" />
     <Compile Include="CSharp\CodeIssues\LocalVariableHidesMemberIssueTests.cs" />
     <Compile Include="CSharp\CodeIssues\LocalVariableNotUsedIssueTests.cs" />
     <Compile Include="CSharp\CodeIssues\LocalVariableOnlyAssignedIssueTests.cs" />