/* * 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. */publicclass 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");    }}