ClassSuperclassesIterator.hpp

/*******************************************************************************
 * Copyright IBM Corp. and others 1991
 *
 * This program and the accompanying materials are made available under
 * the terms of the Eclipse Public License 2.0 which accompanies this
 * distribution and is available at https://www.eclipse.org/legal/epl-2.0/
 * or the Apache License, Version 2.0 which accompanies this distribution and
 * is available at https://www.apache.org/licenses/LICENSE-2.0.
 *
 * This Source Code may also be made available under the following
 * Secondary Licenses when the conditions for such availability set
 * forth in the Eclipse Public License, v. 2.0 are satisfied: GNU
 * General Public License, version 2 with the GNU Classpath
 * Exception [1] and GNU General Public License, version 2 with the
 * OpenJDK Assembly Exception [2].
 *
 * [1] https://www.gnu.org/software/classpath/license.html
 * [2] https://openjdk.org/legal/assembly-exception.html
 *
 * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0-only WITH Classpath-exception-2.0 OR GPL-2.0-only WITH OpenJDK-assembly-exception-1.0
 *******************************************************************************/

/**
 * @file
 * @ingroup GC_Structs
 */

#if !defined(CLASSSUPERCLASSESITERATOR_HPP_)
#define CLASSSUPERCLASSESITERATOR_HPP_

#include "j9.h"
#include "j9cfg.h"
#include "j9cp.h"
#include "modron.h"

/**
 * Iterate over the superclasses references of a class
 * @ingroup GC_Structs
 */
class GC_ClassSuperclassesIterator
{
	UDATA _classDepth;
	IDATA _index;
	J9Class **_superclassPtr;

public:
	GC_ClassSuperclassesIterator(J9Class *clazz) :
		_classDepth(J9CLASS_DEPTH(clazz)),
		_index(-1),
		_superclassPtr(clazz->superclasses)
	{};

	J9Class *nextSlot();
	
	/**
	 * Gets the current superclass index.
	 * The high index is at the end of the superclass chain, with 0 being the direct superclass.
	 * @return index of the last superclass returned by nextSlot.
	 * @return -1 if nextSlot has yet to be called.
	 */
	MMINLINE IDATA getIndex() {
		return _index;
	}

};

#endif /* CLASSSUPERCLASSESITERATOR_HPP_ */