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     protected void clear() {
  46         super.clear();
  47         monitors = EMPTY_ARRAY;
  48         locals = EMPTY_ARRAY;
  49         operands = EMPTY_ARRAY;
  50         mode = 0;
  51     }
  52 
  53     @Override
  54     public Object[] getMonitors() {
  55         return monitors;
  56     }
  57 
  58     @Override
  59     public Object[] getLocals() {
  60         return locals;
  61     }
  62 
  63     @Override
  64     public Object[] getStack() {
  65         return operands;
  66     }
  67 
  68     @Override
  69     public String toString() {
  70         StringBuilder retVal = new StringBuilder(super.toString());
  71         if (mode != 0) {
  72             retVal.append("(");
  73             if ((mode & MODE_INTERPRETED) == MODE_INTERPRETED) {
  74                 retVal.append(" interpreted ");
  75             }
  76             if ((mode & MODE_COMPILED) == MODE_COMPILED) {
  77                 retVal.append(" compiled ");
  78             }
  79             retVal.append(")");
  80         }
  81         return retVal.toString();
  82     }
  83 
  84     /*
  85      * Convert primitive value to {@code PrimitiveSlot} object to represent
  86      * a local variable or an element on the operand stack of primitive type.
  87      */
  88 
  89     static PrimitiveSlot asPrimitive(int value) {
  90         return new PrimitiveSlot32(value);
  91     }
  92 
  93     static PrimitiveSlot asPrimitive(long value) {
  94         return new PrimitiveSlot64(value);
  95     }
  96 
  97     private static class PrimitiveSlot32 extends PrimitiveSlot {
  98         final int value;
  99         PrimitiveSlot32(int value) {
 100             this.value = value;
 101         }
 102 
 103         @Override
 104         public int size() {
 105             return 4;
 106         }
 107 
 108         @Override
 109         public int intValue() {
 110             return value;
 111         }
 112 
 113         @Override
 114         public String toString() {
 115             return String.valueOf(value);
 116         }
 117     }
 118 
 119     private static class PrimitiveSlot64 extends PrimitiveSlot {
 120         final long value;
 121         PrimitiveSlot64(long value) {
 122             this.value = value;
 123         }
 124 
 125         @Override
 126         public int size() {
 127             return 8;
 128         }
 129 
 130         @Override
 131         public long longValue() {
 132             return value;
 133         }
 134 
 135         @Override
 136         public String toString() {
 137             return String.valueOf(value);
 138         }
 139     }
 140 }