// // ConstantConditionIssue.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 ("Condition is always 'true' or always 'false'", Description = "Condition is always 'true' or always 'false'.", Category = IssueCategories.CodeQualityIssues, Severity = Severity.Warning, IssueMarker = IssueMarker.Underline)] public class ConstantConditionIssue : ICodeIssueProvider { public IEnumerable GetIssues (BaseRefactoringContext context) { return new GatherVisitor (context).GetIssues (); } class GatherVisitor : GatherVisitorBase { public GatherVisitor (BaseRefactoringContext ctx) : base (ctx) { } public override void VisitConditionalExpression (ConditionalExpression conditionalExpression) { base.VisitConditionalExpression (conditionalExpression); CheckCondition (conditionalExpression.Condition); } public override void VisitIfElseStatement (IfElseStatement ifElseStatement) { base.VisitIfElseStatement (ifElseStatement); CheckCondition (ifElseStatement.Condition); } public override void VisitWhileStatement (WhileStatement whileStatement) { base.VisitWhileStatement (whileStatement); CheckCondition (whileStatement.Condition); } public override void VisitDoWhileStatement (DoWhileStatement doWhileStatement) { base.VisitDoWhileStatement (doWhileStatement); CheckCondition (doWhileStatement.Condition); } public override void VisitForStatement (ForStatement forStatement) { base.VisitForStatement (forStatement); CheckCondition (forStatement.Condition); } void CheckCondition (Expression condition) { if (condition is PrimitiveExpression) return; var resolveResult = ctx.Resolve (condition); if (!(resolveResult.IsCompileTimeConstant && resolveResult.ConstantValue is bool)) return; var value = (bool)resolveResult.ConstantValue; var conditionalExpr = condition.Parent as ConditionalExpression; var ifElseStatement = condition.Parent as IfElseStatement; var valueStr = value.ToString ().ToLower (); CodeAction action; if (conditionalExpr != null) { var replaceExpr = value ? conditionalExpr.TrueExpression : conditionalExpr.FalseExpression; action = new CodeAction ( string.Format (ctx.TranslateString ("Replace '?:' with '{0}' branch"), valueStr), script => script.Replace (conditionalExpr, replaceExpr.Clone ())); } else if (ifElseStatement != null) { action = new CodeAction ( string.Format (ctx.TranslateString ("Replace 'if' with '{0}' branch"), valueStr), script => { var statement = value ? ifElseStatement.TrueStatement : ifElseStatement.FalseStatement; var blockStatement = statement as BlockStatement; if (statement.IsNull || (blockStatement != null && blockStatement.Statements.Count == 0)) { script.Remove (ifElseStatement); return; } TextLocation start, end; if (blockStatement != null) { start = blockStatement.Statements.FirstOrNullObject ().StartLocation; end = blockStatement.Statements.LastOrNullObject ().EndLocation; } else { start = statement.StartLocation; end = statement.EndLocation; } RemoveText (script, ifElseStatement.StartLocation, start); RemoveText (script, end, ifElseStatement.EndLocation); script.FormatText (ifElseStatement.Parent); }); } else { action = new CodeAction ( string.Format (ctx.TranslateString ("Replace expression with '{0}'"), valueStr), script => script.Replace (condition, new PrimitiveExpression (value))); } AddIssue (condition, string.Format (ctx.TranslateString ("Condition is always '{0}'"), valueStr), new [] { action }); } void RemoveText (Script script, TextLocation start, TextLocation end) { var startOffset = script.GetCurrentOffset (start); var endOffset = script.GetCurrentOffset (end); if (startOffset < endOffset) script.RemoveText (startOffset, endOffset - startOffset); } } } }