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Java > Open Source Codes > com > puppycrawl > tools > checkstyle > bcel > ReferenceVisitor


1 //Tested with BCEL-5.1
2 //http://jakarta.apache.org/builds/jakarta-bcel/release/v5.1/
3
4 package com.puppycrawl.tools.checkstyle.bcel;
5
6 import java.util.HashSet JavaDoc;
7 import java.util.Set JavaDoc;
8
9 import org.apache.bcel.classfile.ConstantPool;
10 import org.apache.bcel.classfile.JavaClass;
11 import org.apache.bcel.generic.ConstantPoolGen;
12 import org.apache.bcel.generic.GETFIELD;
13 import org.apache.bcel.generic.GETSTATIC;
14 import org.apache.bcel.generic.INVOKESPECIAL;
15 import org.apache.bcel.generic.INVOKESTATIC;
16 import org.apache.bcel.generic.INVOKEVIRTUAL;
17 import org.apache.bcel.generic.PUTFIELD;
18 import org.apache.bcel.generic.PUTSTATIC;
19
20 import com.puppycrawl.tools.checkstyle.api.Scope;
21 import com.puppycrawl.tools.checkstyle.bcel.classfile.JavaClassDefinition;
22 import com.puppycrawl.tools.checkstyle.bcel.classfile.ReferenceDAO;
23 import com.puppycrawl.tools.checkstyle.bcel.generic.FieldReference;
24 import com.puppycrawl.tools.checkstyle.bcel.generic.GETFIELDReference;
25 import com.puppycrawl.tools.checkstyle.bcel.generic.GETSTATICReference;
26 import com.puppycrawl.tools.checkstyle.bcel.generic.InvokeReference;
27 import com.puppycrawl.tools.checkstyle.bcel.generic.PUTFIELDReference;
28 import com.puppycrawl.tools.checkstyle.bcel.generic.PUTSTATICReference;
29
30 /**
31  * Records references during a deep parse tree traversal.
32  * @author Rick Giles
33  */
34 public final class ReferenceVisitor extends EmptyDeepVisitor
35 {
36     /** singleton */
37     private static ReferenceVisitor sInstance = new ReferenceVisitor();
38
39     /** scope for checking field references */
40     private Set JavaDoc mFieldScopes = new HashSet JavaDoc();
41
42     /** scope for checking method references */
43     private Set JavaDoc mMethodScopes = new HashSet JavaDoc();
44
45     /** maps a JavaClass to a JavaClassDefinition */
46     private ReferenceDAO mReferenceDAO;
47
48     /** access to current constant pool */
49     private ConstantPoolGen mCurrentPoolGen;
50
51     /**
52      * Adds a reference when it visits an instruction that invokes
53      * a method or references a field.
54      * @author Rick Giles
55      * @version 18-Jun-2003
56      */
57     private class GenericVisitor extends org.apache.bcel.generic.EmptyVisitor
58     {
59         /** @see org.apache.bcel.generic.Visitor */
60         public void visitINVOKESPECIAL(INVOKESPECIAL aINVOKESPECIAL)
61         {
62             addInvokeReference(
63                 new InvokeReference(aINVOKESPECIAL, mCurrentPoolGen));
64         }
65
66         /** @see org.apache.bcel.generic.Visitor */
67         public void visitINVOKESTATIC(INVOKESTATIC aINVOKESTATIC)
68         {
69             addInvokeReference(
70                 new InvokeReference(aINVOKESTATIC, mCurrentPoolGen));
71         }
72
73         /** @see org.apache.bcel.generic.Visitor */
74         public void visitINVOKEVIRTUAL(INVOKEVIRTUAL aINVOKEVIRTUAL)
75         {
76             addInvokeReference(
77                 new InvokeReference(aINVOKEVIRTUAL, mCurrentPoolGen));
78         }
79
80         /** @see org.apache.bcel.generic.Visitor */
81         public void visitGETSTATIC(GETSTATIC aGETSTATIC)
82         {
83             addFieldReference(
84                 new GETSTATICReference(aGETSTATIC, mCurrentPoolGen));
85         }
86
87         /** @see org.apache.bcel.generic.Visitor */
88         public void visitGETFIELD(GETFIELD aGETFIELD)
89         {
90             addFieldReference(
91                 new GETFIELDReference(aGETFIELD, mCurrentPoolGen));
92         }
93
94         /** @see org.apache.bcel.generic.Visitor */
95         public void visitPUTSTATIC(PUTSTATIC aPUTSTATIC)
96         {
97             addFieldReference(
98                 new PUTSTATICReference(aPUTSTATIC, mCurrentPoolGen));
99         }
100
101         /** @see org.apache.bcel.generic.Visitor */
102         public void visitPUTFIELD(PUTFIELD aPUTFIELD)
103         {
104             addFieldReference(
105                 new PUTFIELDReference(aPUTFIELD, mCurrentPoolGen));
106         }
107     }
108
109     /** prevent client construction */
110     private ReferenceVisitor()
111     {
112         setGenericVisitor(new GenericVisitor());
113         addFieldScope(Scope.PRIVATE);
114     }
115
116     /**
117      * Returns the singleton ReferencesVisitor
118      * @return the singleton
119      */
120     public static ReferenceVisitor getInstance()
121     {
122         return sInstance;
123     }
124
125     /**
126      * Adds an invoke reference to the reference DAO.
127      * @param aReference the reference.
128      */
129     private void addInvokeReference(InvokeReference aReference)
130     {
131         getReferenceDAO().addInvokeReference(aReference);
132     }
133
134     /**
135      * Adds an field reference to the reference DAO.
136      * @param aReference the reference.
137      */
138     private void addFieldReference(FieldReference aReference)
139     {
140         getReferenceDAO().addFieldReference(aReference);
141     }
142
143     /** @see com.puppycrawl.tools.checkstyle.bcel.IDeepVisitor */
144     public void visitSet(Set JavaDoc aJavaClasses)
145     {
146         mReferenceDAO =
147             new ReferenceDAO(aJavaClasses, mFieldScopes, mMethodScopes);
148     }
149
150     /**
151      * Gets the reference DAO.
152      * @return the reference DAO.
153      */
154     public ReferenceDAO getReferenceDAO()
155     {
156         return mReferenceDAO;
157     }
158
159     /** @see com.puppycrawl.tools.checkstyle.bcel.IDeepVisitor */
160     public void visitObject(Object JavaDoc aObject)
161     {
162         final JavaClass javaClass = (JavaClass) aObject;
163         final ConstantPool pool = javaClass.getConstantPool();
164         mCurrentPoolGen = new ConstantPoolGen(pool);
165     }
166
167     /**
168      * Finds the JavaClassDefinition for a given JavaClass.
169      * @param aJavaClass the JavaClass.
170      * @return the JavaClassDefinition for aJavaClass.
171      */
172     public JavaClassDefinition findJavaClassDef(JavaClass aJavaClass)
173     {
174         return getReferenceDAO().findJavaClassDef(aJavaClass);
175     }
176
177     /**
178      * Includes a scope in the scope for checking field references.
179      * @param aScope the scope to include.
180      */
181     public void addFieldScope(Scope aScope)
182     {
183         mFieldScopes.add(aScope);
184     }
185
186     /**
187      * Includes a scope in the scope for checking method references.
188      * @param aScope the scope to include.
189      */
190     public void addMethodScope(Scope aScope)
191     {
192         mMethodScopes.add(aScope);
193     }
194 }
195
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