/*******************************************************************************
 * Copyright (c) 2000, 2001, 2002 International Business Machines Corp. and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v0.5 
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v05.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 ******************************************************************************/
package net.sourceforge.phpdt.internal.compiler.ast;

import net.sourceforge.phpdt.internal.compiler.IAbstractSyntaxTreeVisitor;
import net.sourceforge.phpdt.internal.compiler.flow.*;
import net.sourceforge.phpdt.internal.compiler.lookup.*;

public class Break extends BranchStatement {
	
	public Break(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;
		if (label == null) {
			targetContext = flowContext.getTargetContextForDefaultBreak();
		} else {
			targetContext = flowContext.getTargetContextForBreakLabel(label);
		}
		if (targetContext == null) {
			if (label == null) {
				currentScope.problemReporter().invalidBreak(this);
			} else {
				currentScope.problemReporter().undefinedLabel(this); // need to improve
			}
		} else {
			targetLabel = targetContext.breakLabel();
			targetContext.recordBreakFrom(flowInfo);
			FlowContext traversedContext = flowContext;
			int subIndex = 0, maxSub = 5;
			subroutines = new AstNode[maxSub];
			while (true) {
				AstNode sub;
				if ((sub = traversedContext.subRoutine()) != null) {
					if (subIndex == maxSub) {
						System.arraycopy(
							subroutines,
							0,
							(subroutines = new AstNode[maxSub *= 2]),
							0,
							subIndex);
						// grow
					}
					subroutines[subIndex++] = sub;
					if (sub.cannotReturn()) {
						break;
					}
				}
				// remember the initialization at this
				// point for dealing with blank final variables.
				traversedContext.recordReturnFrom(flowInfo.unconditionalInits());

				if (traversedContext == targetContext) {
					break;
				} else {
					traversedContext = traversedContext.parent;
				}
			}
			// resize subroutines
			if (subIndex != maxSub) {
				System.arraycopy(
					subroutines,
					0,
					(subroutines = new AstNode[subIndex]),
					0,
					subIndex);
			}
		}
		return FlowInfo.DeadEnd;
	}
	
	public String toString(int tab) {

		String s = tabString(tab);
		s = s + "break "; //$NON-NLS-1$
		if (label != null)
			s = s + new String(label);
		return s;
	}
	
	public void traverse(
		IAbstractSyntaxTreeVisitor visitor,
		BlockScope blockscope) {

		visitor.visit(this, blockscope);
		visitor.endVisit(this, blockscope);
	}
}