/* *******************************************************************
 * Copyright (c) 2002 Palo Alto Research Center, Incorporated (PARC).
 * 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: 
 *     PARC     initial implementation 
 * ******************************************************************/

package org.aspectj.weaver.bcel;

import org.aspectj.apache.bcel.generic.InstructionHandle;
import org.aspectj.apache.bcel.generic.InstructionList;
import org.aspectj.weaver.UnresolvedType;

exceptionRanges are set initially to be low priority. The various setPriority methods should be used accordingly. The priority is
used when we pack the exception table into a method... the exception table should be sorted from high to low priority. Exceptions
we generate for advice is either high priority (higher than anything coming from the original method... most kinds of
non-execution advice) or low priority (lower than anything coming from the original method, for execution advice).

??? This does not account for handler, or any other "statement-level" advice. When such statement level advice happens, we may
want to go to a float level, so we can set the priority of advice to be lower than anything it encloses, and higher than anything
enclosing it.
/**
 * exceptionRanges are set initially to be low priority. The various setPriority methods should be used accordingly. The priority is
 * used when we pack the exception table into a method... the exception table should be sorted from high to low priority. Exceptions
 * we generate for advice is either high priority (higher than anything coming from the original method... most kinds of
 * non-execution advice) or low priority (lower than anything coming from the original method, for execution advice).
 * 
 * <p>
 * ??? This does not account for handler, or any other "statement-level" advice. When such statement level advice happens, we may
 * want to go to a float level, so we can set the priority of advice to be lower than anything it encloses, and higher than anything
 * enclosing it.
 */

/*
 * we're actually using the fact that we're an instruction targeter, for the handler
 */
public final class ExceptionRange extends Range {

	private InstructionHandle handler;
	private final UnresolvedType exceptionType;
	private final int priority;

	// ---- initialization

	
After this constructor is called, this range is not well situated unless associateWithTargets is called XXX priority should be fixed /**
	 * After this constructor is called, this range is not well situated unless {@link #associateWithTargets} is called
	 * 
	 * XXX priority should be fixed
	 */
	public ExceptionRange(InstructionList body, UnresolvedType exceptionType, int priority) {
		super(body);
		this.exceptionType = exceptionType;
		this.priority = priority;
	}

	
Params:
insideExisting – /**
	 * @param insideExisting
	 */
	public ExceptionRange(InstructionList body, UnresolvedType exceptionType, boolean insideExisting) {
		this(body, exceptionType, insideExisting ? Integer.MAX_VALUE : -1);
	}

	public void associateWithTargets(InstructionHandle start, InstructionHandle end, InstructionHandle handler) {
		// assert body.contains(start) && body.contains(end) && body.contains(handler)
		this.start = start;
		this.end = end;
		this.handler = handler;
		start.addTargeter(this);
		end.addTargeter(this);
		handler.addTargeter(this);
	}

	// ----

	public InstructionHandle getHandler() {
		return handler;
	}

	public UnresolvedType getCatchType() {
		return exceptionType;
	}

	public int getPriority() {
		return priority;
	}

	// ---- from object

	public String toString() {
		String str;
		if (exceptionType == null) {
			str = "finally";
		} else {
			str = "catch " + exceptionType;
		}
		// if (priority >= 0 && priority < Integer.MAX_VALUE) {
		// str += " (priority " + priority + ")";
		// }
		return str;
	}

	public boolean equals(Object other) {
		if (!(other instanceof ExceptionRange))
			return false;
		ExceptionRange o = (ExceptionRange) other;
		return o.getStart() == getStart() && o.getEnd() == getEnd() && o.handler == handler
				&& ((o.exceptionType == null) ? (exceptionType == null) : o.exceptionType.equals(exceptionType))
				&& o.priority == priority;
	}

	private volatile int hashCode = 0;

	public int hashCode() {
		if (hashCode == 0) {
			int ret = 17;
			ret = 37 * ret + getStart().hashCode();
			ret = 37 * ret + getEnd().hashCode();
			ret = 37 * ret + handler.hashCode();
			ret = 37 * ret + ((exceptionType == null) ? 0 : exceptionType.hashCode());
			ret = 37 * ret + priority;
			hashCode = ret;
		}
		return hashCode;
	}

	public void updateTarget(InstructionHandle oldIh, InstructionHandle newIh, InstructionList newBody) {
		super.updateTarget(oldIh, newIh, newBody);
		// we're guaranteed that start, end, and handler are distinct instruction handles.
		if (oldIh == handler) {
			handler = newIh;
		}
	}

	public static boolean isExceptionStart(InstructionHandle ih) {
		if (!isRangeHandle(ih))
			return false;
		Range r = getRange(ih);
		if (!(r instanceof ExceptionRange))
			return false;
		ExceptionRange er = (ExceptionRange) r;
		return er.getStart() == ih;
	}

	public static boolean isExceptionEnd(InstructionHandle ih) {
		if (!isRangeHandle(ih))
			return false;
		Range r = getRange(ih);
		if (!(r instanceof ExceptionRange))
			return false;
		ExceptionRange er = (ExceptionRange) r;
		return er.getEnd() == ih;
	}

}