/*
* 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);
}
}