| /* |
| * Copyright 2003-2007 the original author or authors. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.codehaus.groovy.control; |
| |
| import java.util.Iterator; |
| import java.util.LinkedList; |
| |
| import org.codehaus.groovy.ast.ClassCodeVisitorSupport; |
| import org.codehaus.groovy.ast.stmt.BreakStatement; |
| import org.codehaus.groovy.ast.stmt.ContinueStatement; |
| import org.codehaus.groovy.ast.stmt.DoWhileStatement; |
| import org.codehaus.groovy.ast.stmt.ForStatement; |
| import org.codehaus.groovy.ast.stmt.Statement; |
| import org.codehaus.groovy.ast.stmt.SwitchStatement; |
| import org.codehaus.groovy.ast.stmt.WhileStatement; |
| |
| /** |
| * This class checks the handling of labels in the AST |
| * |
| * @author Jochen Theodorou |
| */ |
| public class LabelVerifier extends ClassCodeVisitorSupport { |
| |
| private SourceUnit source; |
| private LinkedList visitedLabels; |
| private LinkedList continueLabels; |
| private LinkedList breakLabels; |
| boolean inLoop=false; |
| boolean inSwitch=false; |
| |
| public LabelVerifier(SourceUnit src) { |
| source = src; |
| } |
| |
| protected SourceUnit getSourceUnit() { |
| return source; |
| } |
| |
| private void init(){ |
| visitedLabels = new LinkedList(); |
| continueLabels = new LinkedList(); |
| breakLabels = new LinkedList(); |
| inLoop=false; |
| inSwitch=false; |
| } |
| |
| protected void visitClassCodeContainer(Statement code) { |
| init(); |
| super.visitClassCodeContainer(code); |
| assertNoLabelsMissed(); |
| } |
| |
| public void visitStatement(Statement statement) { |
| String label = statement.getStatementLabel(); |
| |
| if (label!=null) { |
| for (Iterator iter = breakLabels.iterator(); iter.hasNext();) { |
| BreakStatement element = (BreakStatement) iter.next(); |
| if (element.getLabel().equals(label)) iter.remove(); |
| } |
| |
| for (Iterator iter = continueLabels.iterator(); iter.hasNext();) { |
| ContinueStatement element = (ContinueStatement) iter.next(); |
| if (element.getLabel().equals(label)) iter.remove(); |
| } |
| |
| visitedLabels.add(label); |
| } |
| |
| super.visitStatement(statement); |
| } |
| |
| public void visitForLoop(ForStatement forLoop) { |
| boolean oldInLoop = inLoop; |
| inLoop = true; |
| super.visitForLoop(forLoop); |
| inLoop = oldInLoop; |
| } |
| |
| public void visitDoWhileLoop(DoWhileStatement loop) { |
| boolean oldInLoop = inLoop; |
| inLoop = true; |
| super.visitDoWhileLoop(loop); |
| inLoop = oldInLoop; |
| } |
| |
| public void visitWhileLoop(WhileStatement loop) { |
| boolean oldInLoop = inLoop; |
| inLoop = true; |
| super.visitWhileLoop(loop); |
| inLoop = oldInLoop; |
| } |
| |
| public void visitBreakStatement(BreakStatement statement) { |
| String label = statement.getLabel(); |
| boolean hasNamedLabel = label!=null; |
| if (!hasNamedLabel && !inLoop && !inSwitch) { |
| addError("the break statement is only allowed inside loops or switches",statement); |
| } else if (hasNamedLabel && !inLoop) { |
| addError("the break statement with named label is only allowed inside loops",statement); |
| } |
| if (label!=null) { |
| boolean found=false; |
| for (Iterator iter = visitedLabels.iterator(); iter.hasNext();) { |
| String element = (String) iter.next(); |
| if (element.equals(label)) { |
| found = true; |
| break; |
| } |
| } |
| if (!found) breakLabels.add(statement); |
| } |
| |
| super.visitBreakStatement(statement); |
| } |
| |
| public void visitContinueStatement(ContinueStatement statement) { |
| String label = statement.getLabel(); |
| boolean hasNamedLabel = label!=null; |
| if (!hasNamedLabel && !inLoop) { |
| addError("the continue statement is only allowed inside loops",statement); |
| } |
| if (label!=null) { |
| boolean found=false; |
| for (Iterator iter = visitedLabels.iterator(); iter.hasNext();) { |
| String element = (String) iter.next(); |
| if (element.equals(label)) { |
| found = true; |
| break; |
| } |
| } |
| if (!found) continueLabels.add(statement); |
| } |
| |
| super.visitContinueStatement(statement); |
| } |
| |
| protected void assertNoLabelsMissed() { |
| //TODO: report multiple missing labels of the same name only once |
| for (Iterator iter = continueLabels.iterator(); iter.hasNext();) { |
| ContinueStatement element = (ContinueStatement) iter.next(); |
| addError("continue to missing label",element); |
| } |
| for (Iterator iter = breakLabels.iterator(); iter.hasNext();) { |
| BreakStatement element = (BreakStatement) iter.next(); |
| addError("break to missing label",element); |
| } |
| } |
| |
| public void visitSwitch(SwitchStatement statement) { |
| inSwitch=true; |
| super.visitSwitch(statement); |
| } |
| |
| } |