1 /*
   2  * Copyright (c) 1998, 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 
  26 package com.sun.tools.jdi;
  27 
  28 import com.sun.jdi.ClassNotLoadedException;
  29 import com.sun.jdi.InvalidTypeException;
  30 import com.sun.jdi.Value;
  31 import com.sun.jdi.VirtualMachine;
  32 
  33 abstract class ValueImpl extends MirrorImpl implements Value {
  34 
  35     ValueImpl(VirtualMachine aVm) {
  36         super(aVm);
  37     }
  38 
  39     static ValueImpl prepareForAssignment(Value value,
  40                                           ValueContainer destination)
  41                   throws InvalidTypeException, ClassNotLoadedException {
  42         if (value == null) {
  43             /*
  44              * TO DO: Centralize JNI signature knowledge
  45              */
  46             if (destination.signature().length() == 1) {
  47                 throw new InvalidTypeException("Can't set a primitive type to null");
  48             }
  49             if (destination.signature().charAt(0) == 'Q') {
  50                 throw new InvalidTypeException("Can't set an inline type to null");
  51             }
  52             return null;    // no further checking or conversion necessary
  53         } else {
  54             return ((ValueImpl)value).prepareForAssignmentTo(destination);
  55         }
  56     }
  57 
  58     static byte typeValueKey(Value val) {
  59         if (val == null) {
  60             return JDWP.Tag.OBJECT;
  61         } else {
  62             return ((ValueImpl)val).typeValueKey();
  63         }
  64     }
  65 
  66     abstract ValueImpl prepareForAssignmentTo(ValueContainer destination)
  67                  throws InvalidTypeException, ClassNotLoadedException;
  68 
  69     abstract byte typeValueKey();
  70 }