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Java > Open Source Codes > org > codehaus > aspectwerkz > transform > inlining > weaver > AfterObjectInitializationCodeAdapter


1 /**************************************************************************************
2  * Copyright (c) Jonas Bonér, Alexandre Vasseur. All rights reserved. *
3  * http://aspectwerkz.codehaus.org *
4  * ---------------------------------------------------------------------------------- *
5  * The software in this package is published under the terms of the LGPL license *
6  * a copy of which has been included with this distribution in the license.txt file. *
7  **************************************************************************************/
8 package org.codehaus.aspectwerkz.transform.inlining.weaver;
9
10 import org.objectweb.asm.CodeAdapter;
11 import org.objectweb.asm.CodeVisitor;
12 import org.codehaus.aspectwerkz.transform.TransformationConstants;
13 import org.codehaus.aspectwerkz.annotation.instrumentation.asm.AsmAnnotationHelper;
14
15 /**
16  * A visitor that keeps track of NEW and INVOKESPECIAL when within a constructor
17  * to flag when the object initialization has been reached (after this/super call).
18  * <p/>
19  * No regular weaving should occur before it since this(XXJP.invoke(this)) is not allowed Java code
20  *
21  * @author <a HREF="mailto:alex AT gnilux DOT com">Alexandre Vasseur</a>
22  */
23 public class AfterObjectInitializationCodeAdapter extends CodeAdapter implements TransformationConstants {
24
25     private String JavaDoc m_callerMemberName;
26     private int m_newCount = 0;
27     private int m_invokeSpecialCount = 0;
28     protected boolean m_isObjectInitialized = false;
29
30     public AfterObjectInitializationCodeAdapter(CodeVisitor cv, String JavaDoc callerMemberName) {
31         super(cv);
32         m_callerMemberName = callerMemberName;
33         // object initialization matters within constructors only
34 if (!m_callerMemberName.equals(INIT_METHOD_NAME)) {
35             m_isObjectInitialized = true;
36         }
37     }
38
39     public void visitTypeInsn(int opcode, String JavaDoc desc) {
40         if (opcode == NEW) {
41             m_newCount++;
42         }
43         super.visitTypeInsn(opcode, desc);
44     }
45
46     protected boolean queryCurrentMethodInsn(final int opcode,
47                                 final String JavaDoc calleeClassName,
48                                 final String JavaDoc calleeMethodName,
49                                 final String JavaDoc calleeMethodDesc) {
50         int localInvokeSpecialCount = m_invokeSpecialCount;
51         int localNewCount = m_newCount;
52
53         if (opcode == INVOKESPECIAL) {
54             localInvokeSpecialCount++;
55         }
56
57         if (m_callerMemberName.equals(INIT_METHOD_NAME)) {
58             // in ctor
59 // make sure we are after object initialization ie after
60 // the INVOKESPECIAL for this(..) / super(..)
61 // that is we have seen an INVOKESPECIAL while newCount == 0
62 // or while newCount == invokeSpecialCount - 1
63 // [ ie same with numberOfInvokeSpecialCount = 1 ]
64 if (opcode == INVOKESPECIAL) {
65                 if (localNewCount == localInvokeSpecialCount -1) {
66                     return true;
67                 }
68             }
69             return false;
70         }
71         return false;
72     }
73
74     public void visitMethodInsn(final int opcode,
75                                 final String JavaDoc calleeClassName,
76                                 final String JavaDoc calleeMethodName,
77                                 final String JavaDoc calleeMethodDesc) {
78         if (opcode == INVOKESPECIAL) {
79             m_invokeSpecialCount++;
80         }
81
82         if (m_callerMemberName.equals(INIT_METHOD_NAME)) {
83             // in ctor
84 // make sure we are after object initialization ie after
85 // the INVOKESPECIAL for this(..) / super(..)
86 // that is we have seen an INVOKESPECIAL while newCount == 0
87 // or while newCount == invokeSpecialCount - 1
88 // [ ie same with numberOfInvokeSpecialCount = 1 ]
89 if (opcode == INVOKESPECIAL) {
90                 if (m_newCount == m_invokeSpecialCount -1) {
91                     m_isObjectInitialized = true;
92                 }
93             }
94         }
95         super.visitMethodInsn(opcode, calleeClassName, calleeMethodName, calleeMethodDesc);
96     }
97 }
98
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