1/*
2 * Copyright (c) 1998, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26package com.sun.jdi;
27
28/**
29 * A local variable in the target VM. Each variable declared within a
30 * {@link Method} has its own LocalVariable object. Variables of the same
31 * name declared in different scopes have different LocalVariable objects.
32 * LocalVariables can be used alone to retrieve static information
33 * about their declaration, or can be used in conjunction with a
34 * {@link StackFrame} to set and get values.
35 *
36 * @see StackFrame
37 * @see Method
38 *
39 * @author Robert Field
40 * @author Gordon Hirsch
41 * @author James McIlree
42 * @since  1.3
43 */
44
45public interface LocalVariable extends Mirror, Comparable<LocalVariable> {
46
47    /**
48     * Gets the name of the local variable.
49     *
50     * @return a string containing the name.
51     */
52    String name();
53
54    /**
55     * Returns a text representation of the type
56     * of this variable.
57     * Where the type is the type specified in the declaration
58     * of this local variable.
59     * <P>
60     * This type name is always available even if
61     * the type has not yet been created or loaded.
62     *
63     * @return a String representing the
64     * type of this local variable.
65
66     */
67    String typeName();
68
69    /**
70     * Returns the type of this variable.
71     * Where the type is the type specified in the declaration
72     * of this local variable.
73     * <P>
74     * Note: if the type of this variable is a reference type (class,
75     * interface, or array) and it has not been created or loaded
76     * by the class loader of the enclosing class,
77     * then ClassNotLoadedException will be thrown.
78     * Also, a reference type may have been loaded but not yet prepared,
79     * in which case the type will be returned
80     * but attempts to perform some operations on the returned type
81     * (e.g. {@link ReferenceType#fields() fields()}) will throw
82     * a {@link ClassNotPreparedException}.
83     * Use {@link ReferenceType#isPrepared()} to determine if
84     * a reference type is prepared.
85     *
86     * @see Type
87     * @see Field#type() Field.type() - for usage examples
88     * @return the {@link Type} of this local variable.
89     * @throws ClassNotLoadedException if the type has not yet been loaded
90     * through the appropriate class loader.
91     */
92    Type type() throws ClassNotLoadedException;
93
94    /**
95     * Gets the JNI signature of the local variable.
96     *
97     * @see <a href="doc-files/signature.html">Type Signatures</a>
98     * @return a string containing the signature.
99     */
100    String signature();
101
102    /**
103     * Gets the generic signature for this variable if there is one.
104     * Generic signatures are described in the
105     * <cite>The Java&trade; Virtual Machine Specification</cite>.
106     *
107     * @return a string containing the generic signature, or <code>null</code>
108     * if there is no generic signature.
109     *
110     * @since 1.5
111     */
112    String genericSignature();
113
114    /**
115     * Determines whether this variable can be accessed from the given
116     * {@link StackFrame}.
117     *
118     * See {@link StackFrame#visibleVariables} for a complete description
119     * variable visibility in this interface.
120     *
121     * @param frame the StackFrame querying visibility
122     * @return <code>true</code> if this variable is visible;
123     * <code>false</code> otherwise.
124     * @throws IllegalArgumentException if the stack frame's method
125     * does not match this variable's method.
126     */
127    boolean isVisible(StackFrame frame);
128
129    /**
130     * Determines if this variable is an argument to its method.
131     *
132     * @return <code>true</code> if this variable is an argument;
133     * <code>false</code> otherwise.
134     */
135    boolean isArgument();
136
137    /**
138     * Compares the specified Object with this LocalVariable for equality.
139     *
140     * @return  true if the Object is a LocalVariable, if both LocalVariables
141     * are contained in the same method (as determined by
142     * {@link Method#equals}), and if both LocalVariables mirror
143     * the same declaration within that method
144     */
145    boolean equals(Object obj);
146
147    /**
148     * Returns the hash code value for this LocalVariable.
149     *
150     * @return the integer hash code
151     */
152    int hashCode();
153}
154