BreakStatement.java

/*******************************************************************************
 * Copyright (c) 2000, 2010 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.compiler.ast;

import org.eclipse.jdt.internal.compiler.ASTVisitor;
import org.eclipse.jdt.internal.compiler.flow.*;
import org.eclipse.jdt.internal.compiler.lookup.*;

public class BreakStatement extends BranchStatement {

public BreakStatement(char[] label, int sourceStart, int e) {
	super(label, sourceStart, e);
}

public FlowInfo analyseCode(BlockScope currentScope, FlowContext flowContext, FlowInfo flowInfo) {

	// here requires to generate a sequence of finally blocks invocations depending corresponding
	// to each of the traversed try statements, so that execution will terminate properly.

	// lookup the label, this should answer the returnContext
	FlowContext targetContext = (this.label == null)
		? flowContext.getTargetContextForDefaultBreak()
		: flowContext.getTargetContextForBreakLabel(this.label);

	if (targetContext == null) {
		if (this.label == null) {
			currentScope.problemReporter().invalidBreak(this);
		} else {
			currentScope.problemReporter().undefinedLabel(this);
		}
		return flowInfo; // pretend it did not break since no actual target
	}

	this.initStateIndex =
		currentScope.methodScope().recordInitializationStates(flowInfo);

	this.targetLabel = targetContext.breakLabel();
	FlowContext traversedContext = flowContext;
	int subCount = 0;
	this.subroutines = new SubRoutineStatement[5];

	do {
		SubRoutineStatement sub;
		if ((sub = traversedContext.subroutine()) != null) {
			if (subCount == this.subroutines.length) {
				System.arraycopy(this.subroutines, 0, (this.subroutines = new SubRoutineStatement[subCount*2]), 0, subCount); // grow
			}
			this.subroutines[subCount++] = sub;
			if (sub.isSubRoutineEscaping()) {
				break;
			}
		}
		traversedContext.recordReturnFrom(flowInfo.unconditionalInits());
		traversedContext.recordBreakTo(targetContext);

		if (traversedContext instanceof InsideSubRoutineFlowContext) {
			ASTNode node = traversedContext.associatedNode;
			if (node instanceof TryStatement) {
				TryStatement tryStatement = (TryStatement) node;
				flowInfo.addInitializationsFrom(tryStatement.subRoutineInits); // collect inits
			}
		} else if (traversedContext == targetContext) {
			// only record break info once accumulated through subroutines, and only against target context
			targetContext.recordBreakFrom(flowInfo);
			break;
		}
	} while ((traversedContext = traversedContext.parent) != null);

	// resize subroutines
	if (subCount != this.subroutines.length) {
		System.arraycopy(this.subroutines, 0, (this.subroutines = new SubRoutineStatement[subCount]), 0, subCount);
	}
	return FlowInfo.DEAD_END;
}

public StringBuffer printStatement(int tab, StringBuffer output) {
	printIndent(tab, output).append("break"); //$NON-NLS-1$
	if (this.label != null) output.append(' ').append(this.label);
	return output.append(';');
}

public void traverse(ASTVisitor visitor, BlockScope blockscope) {
	visitor.visit(this, blockscope);
	visitor.endVisit(this, blockscope);
}
}