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
  6  * under the terms of the GNU General Public License version 2 only, as
  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 
 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
 45     public Object[] getMonitors() {
 46         return monitors;
 47     }
 48 
 49     @Override
 50     public Object[] getLocals() {
 51         return locals;
 52     }
 53 
 54     @Override
 55     public Object[] getStack() {
 56         return operands;
 57     }
 58 
 59     @Override
 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 
 80     static PrimitiveSlot asPrimitive(int value) {
 81         return new PrimitiveSlot32(value);
 82     }
 83 
 84     static PrimitiveSlot asPrimitive(long value) {
 85         return new PrimitiveSlot64(value);
 86     }
 87 
 88     private static class PrimitiveSlot32 extends PrimitiveSlot {
 89         final int value;
 90         PrimitiveSlot32(int value) {
 91             this.value = value;
 92         }
 93 
 94         @Override
 95         public int size() {
 96             return 4;
 97         }
 98 
 99         @Override
100         public int intValue() {
101             return value;
102         }
103 
104         @Override
105         public String toString() {
106             return String.valueOf(value);
107         }
108     }
109 
110     private static class PrimitiveSlot64 extends PrimitiveSlot {
111         final long value;
112         PrimitiveSlot64(long value) {
113             this.value = value;
114         }
115 
116         @Override
117         public int size() {
118             return 8;
119         }
120 
121         @Override
122         public long longValue() {
123             return value;
124         }
125 
126         @Override
127         public String toString() {
128             return String.valueOf(value);
129         }
130     }
131 }