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185 lines
6.4 KiB
185 lines
6.4 KiB
// |
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// UnreachableCodeIssue.cs |
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// |
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// Author: |
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// Mansheng Yang <lightyang0@gmail.com> |
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// |
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// Copyright (c) 2012 Mansheng Yang <lightyang0@gmail.com> |
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// |
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// Permission is hereby granted, free of charge, to any person obtaining a copy |
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// of this software and associated documentation files (the "Software"), to deal |
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// in the Software without restriction, including without limitation the rights |
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// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
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// copies of the Software, and to permit persons to whom the Software is |
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// furnished to do so, subject to the following conditions: |
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// |
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// The above copyright notice and this permission notice shall be included in |
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// all copies or substantial portions of the Software. |
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// |
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
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// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
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// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
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// THE SOFTWARE. |
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using System; |
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using System.Collections.Generic; |
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using ICSharpCode.NRefactory.CSharp.Analysis; |
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namespace ICSharpCode.NRefactory.CSharp.Refactoring |
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{ |
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[IssueDescription ("Code is unreachable", |
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Description = "Code is unreachable.", |
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Category = IssueCategories.Redundancies, |
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Severity = Severity.Warning, |
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IssueMarker = IssueMarker.GrayOut)] |
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public class UnreachableCodeIssue : ICodeIssueProvider |
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{ |
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public IEnumerable<CodeIssue> GetIssues (BaseRefactoringContext context) |
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{ |
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return new GatherVisitor (context).GetIssues (); |
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} |
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class GatherVisitor : GatherVisitorBase |
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{ |
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HashSet<AstNode> unreachableNodes; |
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public GatherVisitor (BaseRefactoringContext ctx) |
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: base (ctx) |
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{ |
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unreachableNodes = new HashSet<AstNode> (); |
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} |
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public override void VisitMethodDeclaration (MethodDeclaration methodDeclaration) |
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{ |
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StatementIssueCollector.Collect (this, methodDeclaration.Body); |
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base.VisitMethodDeclaration (methodDeclaration); |
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} |
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public override void VisitLambdaExpression (LambdaExpression lambdaExpression) |
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{ |
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var blockStatement = lambdaExpression.Body as BlockStatement; |
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if (blockStatement != null) |
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StatementIssueCollector.Collect (this, blockStatement); |
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base.VisitLambdaExpression (lambdaExpression); |
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} |
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public override void VisitAnonymousMethodExpression (AnonymousMethodExpression anonymousMethodExpression) |
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{ |
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StatementIssueCollector.Collect (this, anonymousMethodExpression.Body); |
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base.VisitAnonymousMethodExpression (anonymousMethodExpression); |
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} |
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public override void VisitConditionalExpression (ConditionalExpression conditionalExpression) |
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{ |
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var resolveResult = ctx.Resolve (conditionalExpression.Condition); |
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if (resolveResult.ConstantValue is bool) { |
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var condition = (bool)resolveResult.ConstantValue; |
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Expression resultExpr, unreachableExpr; |
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if (condition) { |
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resultExpr = conditionalExpression.TrueExpression; |
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unreachableExpr = conditionalExpression.FalseExpression; |
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} else { |
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resultExpr = conditionalExpression.FalseExpression; |
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unreachableExpr = conditionalExpression.TrueExpression; |
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} |
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unreachableNodes.Add (unreachableExpr); |
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AddIssue (unreachableExpr, ctx.TranslateString ("Remove unreachable code"), |
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script => script.Replace (conditionalExpression, resultExpr.Clone ())); |
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} |
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base.VisitConditionalExpression (conditionalExpression); |
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} |
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protected override void VisitChildren (AstNode node) |
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{ |
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// skip unreachable nodes |
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if (!unreachableNodes.Contains (node)) |
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base.VisitChildren (node); |
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} |
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class StatementIssueCollector : DepthFirstAstVisitor |
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{ |
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GatherVisitor visitor; |
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ReachabilityAnalysis reachability; |
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HashSet<Statement> collectedStatements; |
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private StatementIssueCollector (GatherVisitor visitor, ReachabilityAnalysis reachability) |
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{ |
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collectedStatements = new HashSet<Statement> (); |
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this.visitor = visitor; |
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this.reachability = reachability; |
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} |
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public static void Collect (GatherVisitor visitor, BlockStatement body) |
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{ |
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var reachability = visitor.ctx.CreateReachabilityAnalysis (body); |
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var collector = new StatementIssueCollector (visitor, reachability); |
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collector.VisitBlockStatement (body); |
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} |
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protected override void VisitChildren (AstNode node) |
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{ |
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var statement = node as Statement; |
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if (statement == null || !AddStatement (statement)) |
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base.VisitChildren (node); |
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} |
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bool AddStatement(Statement statement) |
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{ |
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if (reachability.IsReachable (statement)) |
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return false; |
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if (collectedStatements.Contains (statement)) |
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return true; |
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var prevEnd = statement.GetPrevNode ().EndLocation; |
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// group multiple continuous statements into one issue |
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var start = statement.StartLocation; |
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collectedStatements.Add (statement); |
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visitor.unreachableNodes.Add (statement); |
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while (statement.NextSibling is Statement) { |
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statement = (Statement)statement.NextSibling; |
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collectedStatements.Add (statement); |
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visitor.unreachableNodes.Add (statement); |
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} |
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var end = statement.EndLocation; |
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var removeAction = new CodeAction (visitor.ctx.TranslateString ("Remove unreachable code"), |
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script => |
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{ |
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var startOffset = script.GetCurrentOffset (prevEnd); |
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var endOffset = script.GetCurrentOffset (end); |
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script.RemoveText (startOffset, endOffset - startOffset); |
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}); |
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var commentAction = new CodeAction (visitor.ctx.TranslateString ("Comment unreachable code"), |
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script => |
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{ |
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var startOffset = script.GetCurrentOffset (prevEnd); |
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script.InsertText (startOffset, Environment.NewLine + "/*"); |
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var endOffset = script.GetCurrentOffset (end); |
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script.InsertText (endOffset, Environment.NewLine + "*/"); |
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}); |
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var actions = new [] { removeAction, commentAction }; |
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visitor.AddIssue (start, end, visitor.ctx.TranslateString ("Code is unreachable"), actions); |
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return true; |
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} |
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// skip lambda and anonymous method |
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public override void VisitLambdaExpression (LambdaExpression lambdaExpression) |
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{ |
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} |
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public override void VisitAnonymousMethodExpression ( |
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AnonymousMethodExpression anonymousMethodExpression) |
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{ |
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} |
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} |
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} |
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} |
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}
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