1 /*
2  * Copyright (c) 2015, 2017, Oracle and/or its affiliates. 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
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7  * published by the Free Software Foundation.  Oracle designates this
8  * particular file as subject to the "Classpath" exception as provided
9  * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22  * or visit www.oracle.com if you need additional information or have any
23  * questions.
24  */
25 package java.lang;
26 
27 final class LiveStackFrameInfo extends StackFrameInfo implements LiveStackFrame {
28     private static Object[] EMPTY_ARRAY = new Object[0];
29 
30     // These flags must match the values maintained in the VM
31     private static final int MODE_INTERPRETED = 0x01;
32     private static final int MODE_COMPILED    = 0x02;
33 
LiveStackFrameInfo(StackWalker walker)34     LiveStackFrameInfo(StackWalker walker) {
35         super(walker);
36     }
37 
38     // These fields are initialized by the VM if ExtendedOption.LOCALS_AND_OPERANDS is set
39     private Object[] monitors = EMPTY_ARRAY;
40     private Object[] locals = EMPTY_ARRAY;
41     private Object[] operands = EMPTY_ARRAY;
42     private int mode = 0;
43 
44     @Override
getMonitors()45     public Object[] getMonitors() {
46         return monitors;
47     }
48 
49     @Override
getLocals()50     public Object[] getLocals() {
51         return locals;
52     }
53 
54     @Override
getStack()55     public Object[] getStack() {
56         return operands;
57     }
58 
59     @Override
toString()60     public String toString() {
61         StringBuilder retVal = new StringBuilder(super.toString());
62         if (mode != 0) {
63             retVal.append("(");
64             if ((mode & MODE_INTERPRETED) == MODE_INTERPRETED) {
65                 retVal.append(" interpreted ");
66             }
67             if ((mode & MODE_COMPILED) == MODE_COMPILED) {
68                 retVal.append(" compiled ");
69             }
70             retVal.append(")");
71         }
72         return retVal.toString();
73     }
74 
75     /*
76      * Convert primitive value to {@code PrimitiveSlot} object to represent
77      * a local variable or an element on the operand stack of primitive type.
78      */
79 
asPrimitive(int value)80     static PrimitiveSlot asPrimitive(int value) {
81         return new PrimitiveSlot32(value);
82     }
83 
asPrimitive(long value)84     static PrimitiveSlot asPrimitive(long value) {
85         return new PrimitiveSlot64(value);
86     }
87 
88     private static class PrimitiveSlot32 extends PrimitiveSlot {
89         final int value;
PrimitiveSlot32(int value)90         PrimitiveSlot32(int value) {
91             this.value = value;
92         }
93 
94         @Override
size()95         public int size() {
96             return 4;
97         }
98 
99         @Override
intValue()100         public int intValue() {
101             return value;
102         }
103 
104         @Override
toString()105         public String toString() {
106             return String.valueOf(value);
107         }
108     }
109 
110     private static class PrimitiveSlot64 extends PrimitiveSlot {
111         final long value;
PrimitiveSlot64(long value)112         PrimitiveSlot64(long value) {
113             this.value = value;
114         }
115 
116         @Override
size()117         public int size() {
118             return 8;
119         }
120 
121         @Override
longValue()122         public long longValue() {
123             return value;
124         }
125 
126         @Override
toString()127         public String toString() {
128             return String.valueOf(value);
129         }
130     }
131 }
132