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Java > Open Source Codes > com > sun > org > apache > bcel > internal > generic > PUSH


1 package com.sun.org.apache.bcel.internal.generic;
2
3 /* ====================================================================
4  * The Apache Software License, Version 1.1
5  *
6  * Copyright (c) 2001 The Apache Software Foundation. All rights
7  * reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  *
13  * 1. Redistributions of source code must retain the above copyright
14  * notice, this list of conditions and the following disclaimer.
15  *
16  * 2. Redistributions in binary form must reproduce the above copyright
17  * notice, this list of conditions and the following disclaimer in
18  * the documentation and/or other materials provided with the
19  * distribution.
20  *
21  * 3. The end-user documentation included with the redistribution,
22  * if any, must include the following acknowledgment:
23  * "This product includes software developed by the
24  * Apache Software Foundation (http://www.apache.org/)."
25  * Alternately, this acknowledgment may appear in the software itself,
26  * if and wherever such third-party acknowledgments normally appear.
27  *
28  * 4. The names "Apache" and "Apache Software Foundation" and
29  * "Apache BCEL" must not be used to endorse or promote products
30  * derived from this software without prior written permission. For
31  * written permission, please contact apache@apache.org.
32  *
33  * 5. Products derived from this software may not be called "Apache",
34  * "Apache BCEL", nor may "Apache" appear in their name, without
35  * prior written permission of the Apache Software Foundation.
36  *
37  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
38  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
39  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
40  * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
41  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
42  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
43  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
44  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
45  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
46  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
47  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
48  * SUCH DAMAGE.
49  * ====================================================================
50  *
51  * This software consists of voluntary contributions made by many
52  * individuals on behalf of the Apache Software Foundation. For more
53  * information on the Apache Software Foundation, please see
54  * <http://www.apache.org/>.
55  */
56 import com.sun.org.apache.bcel.internal.Constants;
57 import java.io.*;
58
59 /**
60  * Wrapper class for push operations, which are implemented either as BIPUSH,
61  * LDC or xCONST_n instructions.
62  *
63  * @version $Id: PUSH.java,v 1.1.1.1 2001/10/29 20:00:25 jvanzyl Exp $
64  * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
65  */
66 public final class PUSH
67   implements CompoundInstruction, VariableLengthInstruction, InstructionConstants
68 {
69   private Instruction instruction;
70
71   /**
72    * This constructor also applies for values of type short, char, byte
73    *
74    * @param cp Constant pool
75    * @param value to be pushed
76    */
77   public PUSH(ConstantPoolGen cp, int value) {
78     if((value >= -1) && (value <= 5)) // Use ICONST_n
79 instruction = INSTRUCTIONS[Constants.ICONST_0 + value];
80     else if((value >= -128) && (value <= 127)) // Use BIPUSH
81 instruction = new BIPUSH((byte)value);
82     else if((value >= -32768) && (value <= 32767)) // Use SIPUSH
83 instruction = new SIPUSH((short)value);
84     else // If everything fails create a Constant pool entry
85 instruction = new LDC(cp.addInteger(value));
86   }
87
88   /**
89    * @param cp Constant pool
90    * @param value to be pushed
91    */
92   public PUSH(ConstantPoolGen cp, boolean value) {
93     instruction = INSTRUCTIONS[Constants.ICONST_0 + (value? 1 : 0)];
94   }
95
96   /**
97    * @param cp Constant pool
98    * @param value to be pushed
99    */
100   public PUSH(ConstantPoolGen cp, float value) {
101     if(value == 0.0)
102       instruction = FCONST_0;
103     else if(value == 1.0)
104       instruction = FCONST_1;
105     else if(value == 2.0)
106       instruction = FCONST_2;
107     else // Create a Constant pool entry
108 instruction = new LDC(cp.addFloat(value));
109   }
110
111   /**
112    * @param cp Constant pool
113    * @param value to be pushed
114    */
115   public PUSH(ConstantPoolGen cp, long value) {
116     if(value == 0)
117       instruction = LCONST_0;
118     else if(value == 1)
119       instruction = LCONST_1;
120     else // Create a Constant pool entry
121 instruction = new LDC2_W(cp.addLong(value));
122   }
123
124   /**
125    * @param cp Constant pool
126    * @param value to be pushed
127    */
128   public PUSH(ConstantPoolGen cp, double value) {
129     if(value == 0.0)
130       instruction = DCONST_0;
131     else if(value == 1.0)
132       instruction = DCONST_1;
133     else // Create a Constant pool entry
134 instruction = new LDC2_W(cp.addDouble(value));
135   }
136
137   /**
138    * @param cp Constant pool
139    * @param value to be pushed
140    */
141   public PUSH(ConstantPoolGen cp, String JavaDoc value) {
142     if(value == null)
143       instruction = ACONST_NULL;
144     else // Create a Constant pool entry
145 instruction = new LDC(cp.addString(value));
146   }
147
148   /**
149    * @param cp Constant pool
150    * @param value to be pushed
151    */
152   public PUSH(ConstantPoolGen cp, Number JavaDoc value) {
153     if((value instanceof Integer JavaDoc) || (value instanceof Short JavaDoc) || (value instanceof Byte JavaDoc))
154       instruction = new PUSH(cp, value.intValue()).instruction;
155     else if(value instanceof Double JavaDoc)
156       instruction = new PUSH(cp, value.doubleValue()).instruction;
157     else if(value instanceof Float JavaDoc)
158       instruction = new PUSH(cp, value.floatValue()).instruction;
159     else if(value instanceof Long JavaDoc)
160       instruction = new PUSH(cp, value.longValue()).instruction;
161     else
162       throw new ClassGenException("What's this: " + value);
163   }
164
165   /**
166    * @param cp Constant pool
167    * @param value to be pushed
168    */
169   public PUSH(ConstantPoolGen cp, Character JavaDoc value) {
170     this(cp, (int)value.charValue());
171   }
172
173   /**
174    * @param cp Constant pool
175    * @param value to be pushed
176    */
177   public PUSH(ConstantPoolGen cp, Boolean JavaDoc value) {
178     this(cp, value.booleanValue());
179   }
180
181   public final InstructionList getInstructionList() {
182     return new InstructionList(instruction);
183   }
184
185   public final Instruction getInstruction() {
186     return instruction;
187   }
188
189   /**
190    * @return mnemonic for instruction
191    */
192   public String JavaDoc toString() {
193     return instruction.toString() + " (PUSH)";
194   }
195 }
196
197
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