/*
 * Copyright  2000-2004 The Apache Software Foundation
 *
 *  Licensed under the Apache License, Version 2.0 (the "License"); 
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License. 
 *
 */
package org.apache.bcel.generic;

import org.apache.bcel.Constants;
import org.apache.bcel.ExceptionConstants;

/**
 * GETSTATIC - Fetch static field from class
 * 
 * <PRE>
 * Stack: ..., -&gt; ..., value
 * </PRE>
 * 
 * OR
 * 
 * <PRE>
 * Stack: ..., -&gt; ..., value.word1, value.word2
 * </PRE>
 * 
 * @version $Id: GETSTATIC.java 386056 2006-03-15 11:31:56Z tcurdt $
 * @author <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
 */
public class GETSTATIC extends FieldInstruction implements PushInstruction,
		ExceptionThrower {

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;

	/**
	 * Empty constructor needed for the Class.newInstance() statement in
	 * Instruction.readInstruction(). Not to be used otherwise.
	 */
	GETSTATIC() {
	}

	public GETSTATIC(int index) {
		super(Constants.GETSTATIC, index);
	}

	@Override
	public int produceStack(ConstantPoolGen cpg) {
		return getFieldSize(cpg);
	}

	@Override
	public Class<?>[] getExceptions() {
		Class<?>[] cs = new Class[1 + ExceptionConstants.EXCS_FIELD_AND_METHOD_RESOLUTION.length];
		System.arraycopy(ExceptionConstants.EXCS_FIELD_AND_METHOD_RESOLUTION,
				0, cs, 0,
				ExceptionConstants.EXCS_FIELD_AND_METHOD_RESOLUTION.length);
		cs[ExceptionConstants.EXCS_FIELD_AND_METHOD_RESOLUTION.length] = ExceptionConstants.INCOMPATIBLE_CLASS_CHANGE_ERROR;
		return cs;
	}

	/**
	 * Call corresponding visitor method(s). The order is: Call visitor methods
	 * of implemented interfaces first, then call methods according to the class
	 * hierarchy in descending order, i.e., the most specific visitXXX() call
	 * comes last.
	 * 
	 * @param v
	 *            Visitor object
	 */
	@Override
	public void accept(Visitor v) {
		v.visitStackProducer(this);
		v.visitPushInstruction(this);
		v.visitExceptionThrower(this);
		v.visitTypedInstruction(this);
		v.visitLoadClass(this);
		v.visitCPInstruction(this);
		v.visitFieldOrMethod(this);
		v.visitFieldInstruction(this);
		v.visitGETSTATIC(this);
	}
}
