// // ForControlVariableNotModifiedIssue.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.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 GetIssues (BaseRefactoringContext context) { var unit = context.RootNode as SyntaxTree; if (unit == null) return Enumerable.Empty (); return new GatherVisitor (context, unit).GetIssues (); } class GatherVisitor : GatherVisitorBase { SyntaxTree unit; public GatherVisitor (BaseRefactoringContext ctx, SyntaxTree 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.UnresolvedFile, 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")); } } } }