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
26 package 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
45 public 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 <a href="{@docRoot}/../specs/jni/types.html#type-signatures">
96 * type signature</a> of the local variable.
97 *
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 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 }