/*

 * Copyright (c) 1994, 2003, Oracle and/or its affiliates. All rights reserved.

 * 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package sun.tools.tree;

import sun.tools.java.*;

import sun.tools.asm.Assembler;

import sun.tools.asm.Label;

import java.io.PrintStream;

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 BooleanExpression extends ConstantExpression {

    boolean value;

    /**

     * Constructor

     */

    public BooleanExpression(long where, boolean value) {

        super(BOOLEANVAL, where, Type.tBoolean);

        this.value = value;

    }

    /**

     * Get the value

     */

    public Object getValue() {

        return new Integer(value ? 1 : 0);

    }

    /**

     * Check if the expression is equal to a value

     */

    public boolean equals(boolean b) {

        return value == b;

    }

    /**

     * Check if the expression is equal to its default static value

     */

    public boolean equalsDefault() {

        return !value;

    }

    /*

     * Check a "not" expression.

     *

     * cvars is modified so that

     *    cvar.vsTrue indicates variables with a known value if

     *         the expression is true.

     *    cvars.vsFalse indicates variables with a known value if

     *         the expression is false

     *

     * For constant expressions, set the side that corresponds to our

     * already known value to vset.  Set the side that corresponds to the

     * other way to "impossible"

     */

    public void checkCondition(Environment env, Context ctx,

                               Vset vset, Hashtable exp, ConditionVars cvars) {

        if (value) {

            cvars.vsFalse = Vset.DEAD_END;

            cvars.vsTrue = vset;

        } else {

            cvars.vsFalse = vset;

            cvars.vsTrue = Vset.DEAD_END;

        }

    }

    /**

     * Code

     */

    void codeBranch(Environment env, Context ctx, Assembler asm, Label lbl, boolean whenTrue) {

        if (value == whenTrue) {

            asm.add(where, opc_goto, lbl);

        }

    }

    public void codeValue(Environment env, Context ctx, Assembler asm) {

        asm.add(where, opc_ldc, new Integer(value ? 1 : 0));

    }

    /**

     * Print

     */

    public void print(PrintStream out) {

        out.print(value ? "true" : "false");

    }

}