| J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1994-2003 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package sun.tools.tree; |
| 27 | |
| 28 | import sun.tools.java.*; |
| 29 | import sun.tools.asm.Assembler; |
| 30 | import java.io.PrintStream; |
| 31 | |
| 32 | /** |
| 33 | * WARNING: The contents of this source file are not part of any |
| 34 | * supported API. Code that depends on them does so at its own risk: |
| 35 | * they are subject to change or removal without notice. |
| 36 | */ |
| 37 | public |
| 38 | class NullExpression extends ConstantExpression { |
| 39 | /** |
| 40 | * Constructor |
| 41 | */ |
| 42 | public NullExpression(long where) { |
| 43 | super(NULL, where, Type.tNull); |
| 44 | } |
| 45 | |
| 46 | /** |
| 47 | * Check if the expression is equal to a value |
| 48 | */ |
| 49 | public boolean equals(int i) { |
| 50 | return i == 0; |
| 51 | } |
| 52 | |
| 53 | public boolean isNull() { |
| 54 | return true; |
| 55 | } |
| 56 | |
| 57 | /** |
| 58 | * Code |
| 59 | */ |
| 60 | public void codeValue(Environment env, Context ctx, Assembler asm) { |
| 61 | asm.add(where, opc_aconst_null); |
| 62 | } |
| 63 | |
| 64 | /** |
| 65 | * Print |
| 66 | */ |
| 67 | public void print(PrintStream out) { |
| 68 | out.print("null"); |
| 69 | } |
| 70 | } |