LengthExpression.java

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package sun.tools.tree;

import sun.tools.java.*;
import sun.tools.asm.Assembler;
import java.util.Hashtable;

/**
 * WARNING: The contents of this source file are not part of any
 * supported API.  Code that depends on them does so at its own risk:
 * they are subject to change or removal without notice.
 */
public
class LengthExpression extends UnaryExpression {
    /**
     * Constructor
     */
    public LengthExpression(long where, Expression right) {
	super(LENGTH, where, Type.tInt, right);
    }
 
    /**
     * Select the type of the expression
     */
    public Vset checkValue(Environment env, Context ctx, Vset vset, Hashtable exp) {
	vset = right.checkValue(env, ctx, vset, exp);
	if (!right.type.isType(TC_ARRAY)) {
	    env.error(where, "invalid.length", right.type);
	}
	return vset;
    }

    /**
     * Code
     */
    public void codeValue(Environment env, Context ctx, Assembler asm) {
	right.codeValue(env, ctx, asm);
	asm.add(where, opc_arraylength);
    }
}