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comparison agent/src/share/classes/sun/jvm/hotspot/interpreter/BytecodeLoadConstant.java @ 0:a61af66fc99e jdk7-b24

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Initial load
author duke
date Sat, 01 Dec 2007 00:00:00 +0000
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children c18cbe5936b8
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-1:000000000000 0:a61af66fc99e
1 /*
2 * Copyright 2002-2003 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.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
24
25 package sun.jvm.hotspot.interpreter;
26
27 import sun.jvm.hotspot.oops.*;
28 import sun.jvm.hotspot.utilities.*;
29
30 public class BytecodeLoadConstant extends BytecodeWithCPIndex {
31 BytecodeLoadConstant(Method method, int bci) {
32 super(method, bci);
33 }
34
35 public int index() {
36 return javaCode() == Bytecodes._ldc ?
37 (int) (0xFF & javaByteAt(1))
38 : (int) (0xFFFF & javaShortAt(1));
39 }
40
41 public void verify() {
42 if (Assert.ASSERTS_ENABLED) {
43 Assert.that(isValid(), "check load constant");
44 }
45 }
46
47 public boolean isValid() {
48 int jcode = javaCode();
49 boolean codeOk = jcode == Bytecodes._ldc || jcode == Bytecodes._ldc_w ||
50 jcode == Bytecodes._ldc2_w;
51 if (! codeOk) return false;
52
53 ConstantTag ctag = method().getConstants().getTagAt(index());
54 if (jcode == Bytecodes._ldc2_w) {
55 // has to be double or long
56 return (ctag.isDouble() || ctag.isLong()) ? true: false;
57 } else {
58 // has to be int or float or String or Klass
59 return (ctag.isUnresolvedString() || ctag.isString()
60 || ctag.isUnresolvedKlass() || ctag.isKlass()
61 || ctag.isInt() || ctag.isFloat())? true: false;
62 }
63 }
64
65 public boolean isKlassConstant() {
66 int jcode = javaCode();
67 if (jcode == Bytecodes._ldc2_w) {
68 return false;
69 }
70
71 ConstantTag ctag = method().getConstants().getTagAt(index());
72 return ctag.isKlass() || ctag.isUnresolvedKlass();
73 }
74
75 // return Symbol (if unresolved) or Klass (if resolved)
76 public Oop getKlass() {
77 if (Assert.ASSERTS_ENABLED) {
78 Assert.that(isKlassConstant(), "not a klass literal");
79 }
80 // tag change from 'unresolved' to 'klass' does not happen atomically.
81 // We just look at the object at the corresponding index and
82 // decide based on the oop type.
83 ConstantPool cpool = method().getConstants();
84 int cpIndex = index();
85 Oop oop = cpool.getObjAt(cpIndex);
86 if (oop.isKlass()) {
87 return (Klass) oop;
88 } else if (oop.isSymbol()) {
89 return (Symbol) oop;
90 } else {
91 throw new RuntimeException("should not reach here");
92 }
93 }
94
95 public static BytecodeLoadConstant at(Method method, int bci) {
96 BytecodeLoadConstant b = new BytecodeLoadConstant(method, bci);
97 if (Assert.ASSERTS_ENABLED) {
98 b.verify();
99 }
100 return b;
101 }
102
103 /** Like at, but returns null if the BCI is not at ldc or ldc_w or ldc2_w */
104 public static BytecodeLoadConstant atCheck(Method method, int bci) {
105 BytecodeLoadConstant b = new BytecodeLoadConstant(method, bci);
106 return (b.isValid() ? b : null);
107 }
108
109 public static BytecodeLoadConstant at(BytecodeStream bcs) {
110 return new BytecodeLoadConstant(bcs.method(), bcs.bci());
111 }
112
113 public String getConstantValue() {
114 ConstantPool cpool = method().getConstants();
115 int cpIndex = index();
116 ConstantTag ctag = cpool.getTagAt(cpIndex);
117 if (ctag.isInt()) {
118 return "<int " + Integer.toString(cpool.getIntAt(cpIndex)) +">";
119 } else if (ctag.isLong()) {
120 return "<long " + Long.toString(cpool.getLongAt(cpIndex)) + "L>";
121 } else if (ctag.isFloat()) {
122 return "<float " + Float.toString(cpool.getFloatAt(cpIndex)) + "F>";
123 } else if (ctag.isDouble()) {
124 return "<double " + Double.toString(cpool.getDoubleAt(cpIndex)) + "D>";
125 } else if (ctag.isString() || ctag.isUnresolvedString()) {
126 // tag change from 'unresolved' to 'string' does not happen atomically.
127 // We just look at the object at the corresponding index and
128 // decide based on the oop type.
129 Oop obj = cpool.getObjAt(cpIndex);
130 if (obj.isSymbol()) {
131 Symbol sym = (Symbol) obj;
132 return "<String \"" + sym.asString() + "\">";
133 } else if (obj.isInstance()) {
134 return "<String \"" + OopUtilities.stringOopToString(obj) + "\">";
135 } else {
136 throw new RuntimeException("should not reach here");
137 }
138 } else if (ctag.isKlass() || ctag.isUnresolvedKlass()) {
139 // tag change from 'unresolved' to 'klass' does not happen atomically.
140 // We just look at the object at the corresponding index and
141 // decide based on the oop type.
142 Oop obj = cpool.getObjAt(cpIndex);
143 if (obj.isKlass()) {
144 Klass k = (Klass) obj;
145 return "<Class " + k.getName().asString() + "@" + k.getHandle() + ">";
146 } else if (obj.isSymbol()) {
147 Symbol sym = (Symbol) obj;
148 return "<Class " + sym.asString() + ">";
149 } else {
150 throw new RuntimeException("should not reach here");
151 }
152 } else {
153 if (Assert.ASSERTS_ENABLED) {
154 Assert.that(false, "invalid load constant type");
155 }
156 return null;
157 }
158 }
159
160 public String toString() {
161 StringBuffer buf = new StringBuffer();
162 buf.append(getJavaBytecodeName());
163 buf.append(spaces);
164 buf.append('#');
165 buf.append(Integer.toString(index()));
166 buf.append(spaces);
167 buf.append(getConstantValue());
168 if (code() != javaCode()) {
169 buf.append(spaces);
170 buf.append('[');
171 buf.append(getBytecodeName());
172 buf.append(']');
173 }
174 return buf.toString();
175 }
176 }