1   package org.apache.bcel.classfile;
2   
3   /* ====================================================================
4    * The Apache Software License, Version 1.1
5    *
6    * Copyright (c) 2001 The Apache Software Foundation.  All rights
7    * reserved.
8    *
9    * Redistribution and use in source and binary forms, with or without
10   * modification, are permitted provided that the following conditions
11   * are met:
12   *
13   * 1. Redistributions of source code must retain the above copyright
14   *    notice, this list of conditions and the following disclaimer.
15   *
16   * 2. Redistributions in binary form must reproduce the above copyright
17   *    notice, this list of conditions and the following disclaimer in
18   *    the documentation and/or other materials provided with the
19   *    distribution.
20   *
21   * 3. The end-user documentation included with the redistribution,
22   *    if any, must include the following acknowledgment:
23   *       "This product includes software developed by the
24   *        Apache Software Foundation (http://www.apache.org/)."
25   *    Alternately, this acknowledgment may appear in the software itself,
26   *    if and wherever such third-party acknowledgments normally appear.
27   *
28   * 4. The names "Apache" and "Apache Software Foundation" and
29   *    "Apache BCEL" must not be used to endorse or promote products
30   *    derived from this software without prior written permission. For
31   *    written permission, please contact apache@apache.org.
32   *
33   * 5. Products derived from this software may not be called "Apache",
34   *    "Apache BCEL", nor may "Apache" appear in their name, without
35   *    prior written permission of the Apache Software Foundation.
36   *
37   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
38   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
39   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
40   * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
41   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
42   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
43   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
44   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
45   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
46   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
47   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
48   * SUCH DAMAGE.
49   * ====================================================================
50   *
51   * This software consists of voluntary contributions made by many
52   * individuals on behalf of the Apache Software Foundation.  For more
53   * information on the Apache Software Foundation, please see
54   * <http://www.apache.org/>.
55   */
56  
57  import  org.apache.bcel.Constants;
58  import  java.io.*;
59  
60  /***
61   * This class is derived from <em>Attribute</em> and represents a reference
62   * to a <href="http://wwwipd.ira.uka.de/~pizza/gj/">GJ</a> attribute.
63   *
64   * @version $Id: Signature.java,v 1.3 2002/03/11 16:16:35 mdahm Exp $
65   * @author  <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
66   * @see     Attribute
67   */
68  public final class Signature extends Attribute {
69    private int signature_index;
70  
71    /***
72     * Initialize from another object. Note that both objects use the same
73     * references (shallow copy). Use clone() for a physical copy.
74     */
75    public Signature(Signature c) {
76      this(c.getNameIndex(), c.getLength(), c.getSignatureIndex(), c.getConstantPool());
77    }
78  
79    /***
80     * Construct object from file stream.
81     * @param name_index Index in constant pool to CONSTANT_Utf8
82     * @param length Content length in bytes
83     * @param file Input stream
84     * @param constant_pool Array of constants
85     * @throws IOException
86     */
87    Signature(int name_index, int length, DataInputStream file,
88  	   ConstantPool constant_pool) throws IOException
89    {
90      this(name_index, length, file.readUnsignedShort(), constant_pool);
91    }
92  
93    /***
94     * @param name_index Index in constant pool to CONSTANT_Utf8
95     * @param length Content length in bytes
96     * @param constant_pool Array of constants
97     * @param Signature_index Index in constant pool to CONSTANT_Utf8
98     */
99    public Signature(int name_index, int length, int signature_index,
100 		  ConstantPool constant_pool)
101   {
102     super(Constants.ATTR_SIGNATURE, name_index, length, constant_pool);
103     this.signature_index = signature_index;
104   }
105 
106   /***
107    * Called by objects that are traversing the nodes of the tree implicitely
108    * defined by the contents of a Java class. I.e., the hierarchy of methods,
109    * fields, attributes, etc. spawns a tree of objects.
110    *
111    * @param v Visitor object
112    */
113    public void accept(Visitor v) {
114      System.err.println("Visiting non-standard Signature object");
115      v.visitSignature(this);
116    }
117    
118   /***
119    * Dump source file attribute to file stream in binary format.
120    *
121    * @param file Output file stream
122    * @throws IOException
123    */ 
124   public final void dump(DataOutputStream file) throws IOException
125   {
126     super.dump(file);
127     file.writeShort(signature_index);
128   }    
129 
130   /***
131    * @return Index in constant pool of source file name.
132    */  
133   public final int getSignatureIndex() { return signature_index; }    
134 
135   /***
136    * @param Signature_index.
137    */
138   public final void setSignatureIndex(int signature_index) {
139     this.signature_index = signature_index;
140   }    
141 
142   /***
143    * @return GJ signature.
144    */ 
145   public final String getSignature() {
146     ConstantUtf8 c = (ConstantUtf8)constant_pool.getConstant(signature_index, 
147 							     Constants.CONSTANT_Utf8);
148     return c.getBytes();
149   }
150 
151   /***
152    * Extends ByteArrayInputStream to make 'unreading' chars possible.
153    */
154   private static final class MyByteArrayInputStream extends ByteArrayInputStream {
155     MyByteArrayInputStream(String data) { super(data.getBytes()); }
156     final int  mark()                   { return pos; }
157     final String getData()              { return new String(buf); }
158     final void reset(int p)             { pos = p; }
159     final void unread()                 { if(pos > 0) pos--; }
160   }
161 
162   private static boolean identStart(int ch) {
163     return ch == 'T' || ch == 'L';
164   }
165 
166   private static boolean identPart(int ch) {
167     return ch == '/' || ch == ';';
168   }
169 
170   private static final void matchIdent(MyByteArrayInputStream in, StringBuffer buf) {
171     int ch;
172 
173     if((ch = in.read()) == -1)
174       throw new RuntimeException("Illegal signature: " + in.getData() +
175 				 " no ident, reaching EOF");
176 
177     //System.out.println("return from ident:" + (char)ch);
178 
179     if(!identStart(ch)) {
180       StringBuffer buf2 = new StringBuffer();
181 
182       int count = 1;
183       while(Character.isJavaIdentifierPart((char)ch)) {
184 	buf2.append((char)ch);
185 	count++;
186 	ch = in.read();
187       }
188       
189       if(ch == ':') { // Ok, formal parameter
190 	in.skip("Ljava/lang/Object".length());
191 	buf.append(buf2);
192 
193         ch = in.read();
194 	in.unread();
195 	//System.out.println("so far:" + buf2 + ":next:" +(char)ch);
196       } else {
197 	for(int i=0; i < count; i++)
198 	  in.unread();
199       }
200 
201       return;
202     }
203 
204     StringBuffer buf2 = new StringBuffer();
205     ch = in.read();
206 
207     do {
208       buf2.append((char)ch);
209       ch = in.read();
210       //System.out.println("within ident:"+ (char)ch);
211 
212     } while((ch != -1) && (Character.isJavaIdentifierPart((char)ch) || (ch == '/')));
213 
214     buf.append(buf2.toString().replace('/', '.'));
215 
216     //System.out.println("regular return ident:"+ (char)ch + ":" + buf2);
217 
218     if(ch != -1)
219       in.unread();
220   }
221 
222   private static final void matchGJIdent(MyByteArrayInputStream in,
223 					 StringBuffer buf)
224   {
225     int ch;
226 
227     matchIdent(in, buf);
228 
229     ch = in.read();
230     if((ch == '<') || ch == '(') { // Parameterized or method
231       //System.out.println("Enter <");
232       buf.append((char)ch);
233       matchGJIdent(in, buf);
234       
235       while(((ch = in.read()) != '>') && (ch != ')')) { // List of parameters
236 	if(ch == -1)
237 	  throw new RuntimeException("Illegal signature: " + in.getData() +
238 				     " reaching EOF");
239 
240 	//System.out.println("Still no >");
241 	buf.append(", ");
242 	in.unread();
243 	matchGJIdent(in, buf); // Recursive call
244       }
245 
246       //System.out.println("Exit >");
247 
248       buf.append((char)ch);
249     } else
250       in.unread();
251 
252     ch = in.read();
253     if(identStart(ch)) {
254       in.unread();
255       matchGJIdent(in, buf);
256     } else if(ch == ')') {
257       in.unread();
258       return;
259     } else if(ch != ';')
260       throw new RuntimeException("Illegal signature: " + in.getData() + " read " +
261 				 (char)ch);
262   }
263 
264   public static String translate(String s) {
265     //System.out.println("Sig:" + s);
266     StringBuffer buf = new StringBuffer();
267 
268     matchGJIdent(new MyByteArrayInputStream(s), buf);
269 
270     return buf.toString();
271   }
272 
273   public static final boolean isFormalParameterList(String s) {
274     return s.startsWith("<") && (s.indexOf(':') > 0);
275   }
276 
277   public static final boolean isActualParameterList(String s) {
278     return s.startsWith("L") && s.endsWith(">;");
279   }    
280 
281   /***
282    * @return String representation
283    */ 
284   public final String toString() {
285     String s = getSignature();
286 
287     return "Signature(" + s + ")";
288   }    
289 
290   /***
291    * @return deep copy of this attribute
292    */
293   public Attribute copy(ConstantPool constant_pool) {
294     return (Signature)clone();
295   }
296 }
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