ExceptionLabel.java

/*******************************************************************************
 * Copyright (c) 2000, 2009 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.codegen;

import org.eclipse.jdt.core.compiler.CharOperation;
import org.eclipse.jdt.internal.compiler.lookup.TypeBinding;

public class ExceptionLabel extends Label {

	public int ranges[]= { POS_NOT_SET, POS_NOT_SET };

	public int count= 0; // incremented each time placeStart or placeEnd is called

	public TypeBinding exceptionType;

	public ExceptionLabel(CodeStream codeStream, TypeBinding exceptionType) {
		super(codeStream);
		this.exceptionType= exceptionType;
	}

	public void place() {
		// register the handler inside the codeStream then normal place
		this.codeStream.registerExceptionHandler(this);
		this.position= this.codeStream.getPosition();
	}

	public void placeEnd() {
		int endPosition= this.codeStream.position;
		if (this.ranges[this.count - 1] == endPosition) { // start == end ?
			// discard empty exception handler
			this.count--;
		} else {
			this.ranges[this.count++]= endPosition;
		}
	}

	public void placeStart() {
		int startPosition= this.codeStream.position;
		if (this.count > 0 && this.ranges[this.count - 1] == startPosition) { // start == previous end ?
			// reopen current handler
			this.count--;
			return;
		}
		// only need to grow on even additions (i.e. placeStart only)
		int length;
		if (this.count == (length= this.ranges.length)) {
			System.arraycopy(this.ranges, 0, this.ranges= new int[length * 2], 0, length);
		}
		this.ranges[this.count++]= startPosition;
	}

	public String toString() {
		String basic= getClass().getName();
		basic= basic.substring(basic.lastIndexOf('.') + 1);
		StringBuffer buffer= new StringBuffer(basic);
		buffer.append('@').append(Integer.toHexString(hashCode()));
		buffer.append("(type=").append(this.exceptionType == null ? CharOperation.NO_CHAR : this.exceptionType.readableName()); //$NON-NLS-1$
		buffer.append(", position=").append(this.position); //$NON-NLS-1$
		buffer.append(", ranges = "); //$NON-NLS-1$
		if (this.count == 0) {
			buffer.append("[]"); //$NON-NLS-1$
		} else {
			for (int i= 0; i < this.count; i++) {
				if ((i & 1) == 0) {
					buffer.append("[").append(this.ranges[i]); //$NON-NLS-1$
				} else {
					buffer.append(",").append(this.ranges[i]).append("]"); //$NON-NLS-1$ //$NON-NLS-2$
				}
			}
			if ((this.count & 1) == 1) {
				buffer.append(",?]"); //$NON-NLS-1$
			}
		}
		buffer.append(')');
		return buffer.toString();
	}
}