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 }