001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 *  Unless required by applicable law or agreed to in writing, software
012 *  distributed under the License is distributed on an "AS IS" BASIS,
013 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 *  See the License for the specific language governing permissions and
015 *  limitations under the License.
016 *
017 */
018package org.apache.bcel.classfile;
019
020import java.io.ByteArrayInputStream;
021import java.io.DataInput;
022import java.io.DataOutputStream;
023import java.io.IOException;
024
025import org.apache.bcel.Const;
026
027/**
028 * This class is derived from <em>Attribute</em> and represents a reference
029 * to a GJ attribute.
030 *
031 * @see     Attribute
032 */
033public final class Signature extends Attribute {
034
035    private int signature_index;
036
037
038    /**
039     * Initialize from another object. Note that both objects use the same
040     * references (shallow copy). Use clone() for a physical copy.
041     */
042    public Signature(final Signature c) {
043        this(c.getNameIndex(), c.getLength(), c.getSignatureIndex(), c.getConstantPool());
044    }
045
046
047    /**
048     * Construct object from file stream.
049     * @param name_index Index in constant pool to CONSTANT_Utf8
050     * @param length Content length in bytes
051     * @param input Input stream
052     * @param constant_pool Array of constants
053     * @throws IOException
054     */
055    Signature(final int name_index, final int length, final DataInput input, final ConstantPool constant_pool)
056            throws IOException {
057        this(name_index, length, input.readUnsignedShort(), constant_pool);
058    }
059
060
061    /**
062     * @param name_index Index in constant pool to CONSTANT_Utf8
063     * @param length Content length in bytes
064     * @param signature_index Index in constant pool to CONSTANT_Utf8
065     * @param constant_pool Array of constants
066     */
067    public Signature(final int name_index, final int length, final int signature_index, final ConstantPool constant_pool) {
068        super(Const.ATTR_SIGNATURE, name_index, length, constant_pool);
069        this.signature_index = signature_index;
070    }
071
072
073    /**
074     * Called by objects that are traversing the nodes of the tree implicitely
075     * defined by the contents of a Java class. I.e., the hierarchy of methods,
076     * fields, attributes, etc. spawns a tree of objects.
077     *
078     * @param v Visitor object
079     */
080    @Override
081    public void accept( final Visitor v ) {
082        //System.err.println("Visiting non-standard Signature object");
083        v.visitSignature(this);
084    }
085
086
087    /**
088     * Dump source file attribute to file stream in binary format.
089     *
090     * @param file Output file stream
091     * @throws IOException
092     */
093    @Override
094    public void dump( final DataOutputStream file ) throws IOException {
095        super.dump(file);
096        file.writeShort(signature_index);
097    }
098
099
100    /**
101     * @return Index in constant pool of source file name.
102     */
103    public int getSignatureIndex() {
104        return signature_index;
105    }
106
107
108    /**
109     * @param signature_index the index info the constant pool of this signature
110     */
111    public void setSignatureIndex( final int signature_index ) {
112        this.signature_index = signature_index;
113    }
114
115
116    /**
117     * @return GJ signature.
118     */
119    public String getSignature() {
120        final ConstantUtf8 c = (ConstantUtf8) super.getConstantPool().getConstant(signature_index,
121                Const.CONSTANT_Utf8);
122        return c.getBytes();
123    }
124
125    /**
126     * Extends ByteArrayInputStream to make 'unreading' chars possible.
127     */
128    private static final class MyByteArrayInputStream extends ByteArrayInputStream {
129
130        MyByteArrayInputStream(final String data) {
131            super(data.getBytes());
132        }
133
134
135        String getData() {
136            return new String(buf);
137        }
138
139
140        void unread() {
141            if (pos > 0) {
142                pos--;
143            }
144        }
145    }
146
147
148    private static boolean identStart( final int ch ) {
149        return ch == 'T' || ch == 'L';
150    }
151
152
153    private static void matchIdent( final MyByteArrayInputStream in, final StringBuilder buf ) {
154        int ch;
155        if ((ch = in.read()) == -1) {
156            throw new RuntimeException("Illegal signature: " + in.getData()
157                    + " no ident, reaching EOF");
158        }
159        //System.out.println("return from ident:" + (char)ch);
160        if (!identStart(ch)) {
161            final StringBuilder buf2 = new StringBuilder();
162            int count = 1;
163            while (Character.isJavaIdentifierPart((char) ch)) {
164                buf2.append((char) ch);
165                count++;
166                ch = in.read();
167            }
168            if (ch == ':') { // Ok, formal parameter
169                in.skip("Ljava/lang/Object".length());
170                buf.append(buf2);
171                ch = in.read();
172                in.unread();
173                //System.out.println("so far:" + buf2 + ":next:" +(char)ch);
174            } else {
175                for (int i = 0; i < count; i++) {
176                    in.unread();
177                }
178            }
179            return;
180        }
181        final StringBuilder buf2 = new StringBuilder();
182        ch = in.read();
183        do {
184            buf2.append((char) ch);
185            ch = in.read();
186            //System.out.println("within ident:"+ (char)ch);
187        } while ((ch != -1) && (Character.isJavaIdentifierPart((char) ch) || (ch == '/')));
188        buf.append(buf2.toString().replace('/', '.'));
189        //System.out.println("regular return ident:"+ (char)ch + ":" + buf2);
190        if (ch != -1) {
191            in.unread();
192        }
193    }
194
195
196    private static void matchGJIdent( final MyByteArrayInputStream in, final StringBuilder buf ) {
197        int ch;
198        matchIdent(in, buf);
199        ch = in.read();
200        if ((ch == '<') || ch == '(') { // Parameterized or method
201            //System.out.println("Enter <");
202            buf.append((char) ch);
203            matchGJIdent(in, buf);
204            while (((ch = in.read()) != '>') && (ch != ')')) { // List of parameters
205                if (ch == -1) {
206                    throw new RuntimeException("Illegal signature: " + in.getData()
207                            + " reaching EOF");
208                }
209                //System.out.println("Still no >");
210                buf.append(", ");
211                in.unread();
212                matchGJIdent(in, buf); // Recursive call
213            }
214            //System.out.println("Exit >");
215            buf.append((char) ch);
216        } else {
217            in.unread();
218        }
219        ch = in.read();
220        if (identStart(ch)) {
221            in.unread();
222            matchGJIdent(in, buf);
223        } else if (ch == ')') {
224            in.unread();
225            return;
226        } else if (ch != ';') {
227            throw new RuntimeException("Illegal signature: " + in.getData() + " read " + (char) ch);
228        }
229    }
230
231
232    public static String translate( final String s ) {
233        //System.out.println("Sig:" + s);
234        final StringBuilder buf = new StringBuilder();
235        matchGJIdent(new MyByteArrayInputStream(s), buf);
236        return buf.toString();
237    }
238
239
240    // @since 6.0 is no longer final
241    public static boolean isFormalParameterList( final String s ) {
242        return s.startsWith("<") && (s.indexOf(':') > 0);
243    }
244
245
246    // @since 6.0 is no longer final
247    public static boolean isActualParameterList( final String s ) {
248        return s.startsWith("L") && s.endsWith(">;");
249    }
250
251
252    /**
253     * @return String representation
254     */
255    @Override
256    public String toString() {
257        final String s = getSignature();
258        return "Signature: " + s;
259    }
260
261
262    /**
263     * @return deep copy of this attribute
264     */
265    @Override
266    public Attribute copy( final ConstantPool _constant_pool ) {
267        return (Attribute) clone();
268    }
269}