// // RedundantElseIssue.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; namespace ICSharpCode.NRefactory.CSharp.Refactoring { [IssueDescription ("Redundant 'else' keyword", Description = "Redundant 'else' keyword.", Category = IssueCategories.Redundancies, Severity = Severity.Warning, IssueMarker = IssueMarker.GrayOut)] public class RedundantElseIssue : ICodeIssueProvider { public IEnumerable GetIssues (BaseRefactoringContext context) { return new GatherVisitor (context).GetIssues (); } class GatherVisitor : GatherVisitorBase { public GatherVisitor (BaseRefactoringContext ctx) : base(ctx) { } bool HasRundundantElse(IfElseStatement ifElseStatement) { if (ifElseStatement.FalseStatement.IsNull) return false; var blockStatement = ifElseStatement.FalseStatement as BlockStatement; if (blockStatement != null && blockStatement.Statements.Count == 0) return true; var reachability = ctx.CreateReachabilityAnalysis (ifElseStatement.TrueStatement); return !reachability.IsEndpointReachable (ifElseStatement.TrueStatement); } public override void VisitIfElseStatement (IfElseStatement ifElseStatement) { base.VisitIfElseStatement (ifElseStatement); if (HasRundundantElse(ifElseStatement)) { AddIssue (ifElseStatement.ElseToken, ctx.TranslateString ("Remove redundant 'else'"), script => { int start = script.GetCurrentOffset(ifElseStatement.ElseToken.GetPrevNode ().EndLocation); int end; var blockStatement = ifElseStatement.FalseStatement as BlockStatement; if (blockStatement != null) { if (blockStatement.Statements.Count == 0) { // remove empty block end = script.GetCurrentOffset (blockStatement.LBraceToken.StartLocation); script.Remove (blockStatement); } else { // remove block braces end = script.GetCurrentOffset (blockStatement.LBraceToken.EndLocation); script.Remove (blockStatement.RBraceToken); } } else { end = script.GetCurrentOffset(ifElseStatement.ElseToken.EndLocation); } if (end > start) script.RemoveText (start, end - start); script.FormatText (ifElseStatement.Parent); }); } } } } }