1/***
2 * ASM: a very small and fast Java bytecode manipulation framework
3 * Copyright (c) 2000-2007 INRIA, France Telecom
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. Neither the name of the copyright holders nor the names of its
15 *    contributors may be used to endorse or promote products derived from
16 *    this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
28 * THE POSSIBILITY OF SUCH DAMAGE.
29 */
30package org.mockito.asm.signature;
31
32/**
33 * A signature visitor that generates signatures in string format.
34 *
35 * @author Thomas Hallgren
36 * @author Eric Bruneton
37 */
38public class SignatureWriter implements SignatureVisitor {
39
40    /**
41     * Buffer used to construct the signature.
42     */
43    private final StringBuffer buf = new StringBuffer();
44
45    /**
46     * Indicates if the signature contains formal type parameters.
47     */
48    private boolean hasFormals;
49
50    /**
51     * Indicates if the signature contains method parameter types.
52     */
53    private boolean hasParameters;
54
55    /**
56     * Stack used to keep track of class types that have arguments. Each element
57     * of this stack is a boolean encoded in one bit. The top of the stack is
58     * the lowest order bit. Pushing false = *2, pushing true = *2+1, popping =
59     * /2.
60     */
61    private int argumentStack;
62
63    /**
64     * Constructs a new {@link SignatureWriter} object.
65     */
66    public SignatureWriter() {
67    }
68
69    // ------------------------------------------------------------------------
70    // Implementation of the SignatureVisitor interface
71    // ------------------------------------------------------------------------
72
73    public void visitFormalTypeParameter(final String name) {
74        if (!hasFormals) {
75            hasFormals = true;
76            buf.append('<');
77        }
78        buf.append(name);
79        buf.append(':');
80    }
81
82    public SignatureVisitor visitClassBound() {
83        return this;
84    }
85
86    public SignatureVisitor visitInterfaceBound() {
87        buf.append(':');
88        return this;
89    }
90
91    public SignatureVisitor visitSuperclass() {
92        endFormals();
93        return this;
94    }
95
96    public SignatureVisitor visitInterface() {
97        return this;
98    }
99
100    public SignatureVisitor visitParameterType() {
101        endFormals();
102        if (!hasParameters) {
103            hasParameters = true;
104            buf.append('(');
105        }
106        return this;
107    }
108
109    public SignatureVisitor visitReturnType() {
110        endFormals();
111        if (!hasParameters) {
112            buf.append('(');
113        }
114        buf.append(')');
115        return this;
116    }
117
118    public SignatureVisitor visitExceptionType() {
119        buf.append('^');
120        return this;
121    }
122
123    public void visitBaseType(final char descriptor) {
124        buf.append(descriptor);
125    }
126
127    public void visitTypeVariable(final String name) {
128        buf.append('T');
129        buf.append(name);
130        buf.append(';');
131    }
132
133    public SignatureVisitor visitArrayType() {
134        buf.append('[');
135        return this;
136    }
137
138    public void visitClassType(final String name) {
139        buf.append('L');
140        buf.append(name);
141        argumentStack *= 2;
142    }
143
144    public void visitInnerClassType(final String name) {
145        endArguments();
146        buf.append('.');
147        buf.append(name);
148        argumentStack *= 2;
149    }
150
151    public void visitTypeArgument() {
152        if (argumentStack % 2 == 0) {
153            ++argumentStack;
154            buf.append('<');
155        }
156        buf.append('*');
157    }
158
159    public SignatureVisitor visitTypeArgument(final char wildcard) {
160        if (argumentStack % 2 == 0) {
161            ++argumentStack;
162            buf.append('<');
163        }
164        if (wildcard != '=') {
165            buf.append(wildcard);
166        }
167        return this;
168    }
169
170    public void visitEnd() {
171        endArguments();
172        buf.append(';');
173    }
174
175    /**
176     * Returns the signature that was built by this signature writer.
177     *
178     * @return the signature that was built by this signature writer.
179     */
180    public String toString() {
181        return buf.toString();
182    }
183
184    // ------------------------------------------------------------------------
185    // Utility methods
186    // ------------------------------------------------------------------------
187
188    /**
189     * Ends the formal type parameters section of the signature.
190     */
191    private void endFormals() {
192        if (hasFormals) {
193            hasFormals = false;
194            buf.append('>');
195        }
196    }
197
198    /**
199     * Ends the type arguments of a class or inner class type.
200     */
201    private void endArguments() {
202        if (argumentStack % 2 != 0) {
203            buf.append('>');
204        }
205        argumentStack /= 2;
206    }
207}