1 cananian 1.1.2.2 // MethodInfo.java, created Mon Jan 18 22:44:38 1999 by cananian
2 cananian 1.1.2.1 // Copyright (C) 1998 C. Scott Ananian <cananian@alumni.princeton.edu>
3 cananian 1.1.2.1 // Licensed under the terms of the GNU GPL; see COPYING for details.
4 cananian 1.1.2.1 package harpoon.IR.RawClass;
5 cananian 1.1.2.1
6 cananian 1.1.2.1 /**
7 cananian 1.1.2.1 * Each method, and each instance initialization method <init>,
8 cananian 1.1.2.1 * is described by a variable-length <code>method_info</code>
9 cananian 1.1.2.1 * structure.
10 cananian 1.1.2.1 *
11 cananian 1.1.2.1 * @author C. Scott Ananian <cananian@alumni.princeton.edu>
12 cananian 1.2 * @version $Id: MethodInfo.java,v 1.2 2002/02/25 21:05:27 cananian Exp $
13 cananian 1.1.2.1 * @see "The Java Virtual Machine Specification, section 4.6"
14 cananian 1.1.2.1 * @see ClassFile
15 cananian 1.1.2.1 * @see harpoon.ClassFile.HMethod
16 cananian 1.1.2.1 */
17 cananian 1.1.2.1 public class MethodInfo {
18 cananian 1.1.2.1 /** ClassFile in which this method information is found. */
19 cananian 1.1.2.1 protected ClassFile parent;
20 cananian 1.1.2.1
21 cananian 1.1.2.1 /** Access permissions and properties of the method. */
22 cananian 1.1.2.1 public AccessFlags access_flags;
23 cananian 1.1.2.1
24 cananian 1.1.2.1 /** The value of the <code>name_index</code> item must be a valid
25 cananian 1.1.2.1 index into the <code>constant_pool</code> table. The
26 cananian 1.1.2.1 <code>constant_pool</code> entry at that index must be a
27 cananian 1.1.2.1 <code>CONSTANT_Utf8_info</code> structure representing either
28 cananian 1.1.2.1 one of the special internal method names, either <init> or
29 cananian 1.1.2.1 <clint>, or a valid Java method name, stored as a simple
30 cananian 1.1.2.1 (not fully qualified) name. */
31 cananian 1.1.2.1 public int name_index;
32 cananian 1.1.2.1 /** The value of the <code>descriptor_index</code> item must be a
33 cananian 1.1.2.1 valid index into the <code>constant_pool</code> table. The
34 cananian 1.1.2.1 <code>constant_pool</code> entry at that index must be a
35 cananian 1.1.2.1 <code>CONSTANT_Utf8_info</code> structure representing a valid
36 cananian 1.1.2.1 Java method descriptor. */
37 cananian 1.1.2.1 public int descriptor_index;
38 cananian 1.1.2.1
39 cananian 1.1.2.1 /** A method can have any number of optional attributes associated
40 cananian 1.1.2.1 with it. <p> The only attributes defined by this specification
41 cananian 1.1.2.1 for the <code>attributes</code> table of a
42 cananian 1.1.2.1 <code>method_info</code> structure are the <code>Code</code> and
43 cananian 1.1.2.1 <code>Exceptions</code> attributes. */
44 cananian 1.1.2.1 public Attribute attributes[];
45 cananian 1.1.2.1
46 cananian 1.1.2.1 /** Read a single MethodInfo item from an input class bytecode file. */
47 cananian 1.1.2.1 public void read(ClassFile p, ClassDataInputStream in)
48 cananian 1.1.2.1 throws java.io.IOException {
49 cananian 1.1.2.1 this.parent = p;
50 cananian 1.1.2.1
51 cananian 1.1.2.1 access_flags = new AccessFlags(in);
52 cananian 1.1.2.1
53 cananian 1.1.2.1 name_index = in.read_u2();
54 cananian 1.1.2.1 descriptor_index = in.read_u2();
55 cananian 1.1.2.1
56 cananian 1.1.2.1 int attributes_count = in.read_u2();
57 cananian 1.1.2.1 attributes = new Attribute[attributes_count];
58 cananian 1.1.2.1 for (int i=0; i<attributes_count; i++)
59 cananian 1.1.2.1 attributes[i] = Attribute.read(p, in);
60 cananian 1.1.2.1 }
61 cananian 1.1.2.1
62 cananian 1.1.2.1 /** Constructor. */
63 cananian 1.1.2.1 MethodInfo(ClassFile p, ClassDataInputStream in)
64 cananian 1.1.2.1 throws java.io.IOException {
65 cananian 1.1.2.1 read(p, in);
66 cananian 1.1.2.1 }
67 cananian 1.1.2.1 /** Constructor. */
68 cananian 1.1.2.1 public MethodInfo(ClassFile parent, AccessFlags access_flags,
69 cananian 1.1.2.1 int name_index, int descriptor_index,
70 cananian 1.1.2.1 Attribute attributes[]) {
71 cananian 1.1.2.1 this.parent = parent;
72 cananian 1.1.2.1 this.access_flags = access_flags;
73 cananian 1.1.2.1 this.name_index = name_index;
74 cananian 1.1.2.1 this.descriptor_index = descriptor_index;
75 cananian 1.1.2.1 this.attributes = attributes;
76 cananian 1.1.2.1 }
77 cananian 1.1.2.1
78 cananian 1.1.2.1 /** Writes a MethodInfo item out to a class bytecode file. */
79 cananian 1.1.2.1 public void write(ClassDataOutputStream out) throws java.io.IOException {
80 cananian 1.1.2.1 access_flags.write(out);
81 cananian 1.1.2.1 out.write_u2(name_index);
82 cananian 1.1.2.1 out.write_u2(descriptor_index);
83 cananian 1.1.2.1
84 cananian 1.1.2.1 if (attributes.length > 0xFFFF)
85 cananian 1.1.2.1 throw new ClassDataException("Attributes list too long: " +
86 cananian 1.1.2.1 attributes.length);
87 cananian 1.1.2.1 out.write_u2(attributes.length);
88 cananian 1.1.2.1 for (int i=0; i<attributes.length; i++)
89 cananian 1.1.2.1 attributes[i].write(out);
90 cananian 1.1.2.1 }
91 cananian 1.1.2.1
92 cananian 1.1.2.1 // convenience
93 cananian 1.1.2.1 public ConstantUtf8 name_index()
94 cananian 1.1.2.1 { return (ConstantUtf8) parent.constant_pool[name_index]; }
95 cananian 1.1.2.1 public ConstantUtf8 descriptor_index()
96 cananian 1.1.2.1 { return (ConstantUtf8) parent.constant_pool[descriptor_index]; }
97 cananian 1.1.2.1
98 cananian 1.1.2.1 public String name() { return name_index().val; }
99 cananian 1.1.2.1 public String descriptor() { return descriptor_index().val; }
100 cananian 1.1.2.1
101 cananian 1.1.2.1 /** Pretty-print this method_info structure. */
102 cananian 1.1.2.1 public void print(java.io.PrintWriter pw, int indent) {
103 cananian 1.1.2.1 int in=indent;
104 cananian 1.1.2.1 ClassFile.indent(pw, in, "Access Flags: " + access_flags);
105 cananian 1.1.2.1 ClassFile.indent(pw, in, "Name: " + name() + " {"+name_index+"}");
106 cananian 1.1.2.1 ClassFile.indent(pw, in, "Descriptor: " +
107 cananian 1.1.2.1 descriptor() + " {"+descriptor_index+"}");
108 cananian 1.1.2.1 ClassFile.indent(pw, in, "Attributes ["+attributes.length+"]:");
109 cananian 1.1.2.1 for (int i=0; i<attributes.length; i++) {
110 cananian 1.1.2.1 ClassFile.indent(pw, in+1, "#"+i+":");
111 cananian 1.1.2.1 attributes[i].print(pw, in+2);
112 cananian 1.1.2.1 }
113 cananian 1.1.2.1 }
114 cananian 1.2 }