1 /*
2 * Copyright (c) 1999, 2018, 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.tools.javac.jvm;
27
28 import com.sun.tools.javac.code.Type;
29 import com.sun.tools.javac.code.Types;
30 import com.sun.tools.javac.code.Types.UniqueType;
31 import com.sun.tools.javac.util.Name;
32
33
34 /** A JVM class file.
35 *
36 * <p>Generic Java classfiles have one additional attribute for classes,
37 * methods and fields:
38 * <pre>
39 * "Signature" (u4 attr-length, u2 signature-index)
40 * </pre>
41 *
42 * <p>A signature gives the full Java type of a method or field. When
43 * used as a class attribute, it indicates type parameters, followed
44 * by supertype, followed by all interfaces.
45 * <pre>
46 * methodOrFieldSignature ::= type
47 * classSignature ::= [ typeparams ] supertype { interfacetype }
48 * </pre>
49 * <p>The type syntax in signatures is extended as follows:
50 * <pre>{@literal
51 * type ::= ... | classtype | methodtype | typevar
52 * classtype ::= classsig { '.' classsig }
53 * classig ::= 'L' name [typeargs] ';'
54 * methodtype ::= [ typeparams ] '(' { type } ')' type
55 * typevar ::= 'T' name ';'
56 * typeargs ::= '<' type { type } '>'
57 * typeparams ::= '<' typeparam { typeparam } '>'
58 * typeparam ::= name ':' type
59 * }</pre>
60 * <p>This class defines constants used in class files as well
61 * as routines to convert between internal ``.'' and external ``/''
62 * separators in class names.
63 *
64 * <p><b>This is NOT part of any supported API.
65 * If you write code that depends on this, you do so at your own risk.
66 * This code and its internal interfaces are subject to change or
67 * deletion without notice.</b> */
68 public class ClassFile {
69
70 public final static int JAVA_MAGIC = 0xCAFEBABE;
71
72 // see Target
73 public final static int CONSTANT_Utf8 = 1;
74 public final static int CONSTANT_Unicode = 2;
75 public final static int CONSTANT_Integer = 3;
76 public final static int CONSTANT_Float = 4;
77 public final static int CONSTANT_Long = 5;
78 public final static int CONSTANT_Double = 6;
79 public final static int CONSTANT_Class = 7;
80 public final static int CONSTANT_String = 8;
81 public final static int CONSTANT_Fieldref = 9;
82 public final static int CONSTANT_Methodref = 10;
83 public final static int CONSTANT_InterfaceMethodref = 11;
84 public final static int CONSTANT_NameandType = 12;
85 public final static int CONSTANT_MethodHandle = 15;
86 public final static int CONSTANT_MethodType = 16;
87 public final static int CONSTANT_Dynamic = 17;
88 public final static int CONSTANT_InvokeDynamic = 18;
89 public final static int CONSTANT_Module = 19;
90 public final static int CONSTANT_Package = 20;
91
92 public final static int REF_getField = 1;
93 public final static int REF_getStatic = 2;
94 public final static int REF_putField = 3;
95 public final static int REF_putStatic = 4;
96 public final static int REF_invokeVirtual = 5;
97 public final static int REF_invokeStatic = 6;
98 public final static int REF_invokeSpecial = 7;
99 public final static int REF_newInvokeSpecial = 8;
100 public final static int REF_invokeInterface = 9;
101
102 public final static int MAX_PARAMETERS = 0xff;
103 public final static int MAX_DIMENSIONS = 0xff;
104 public final static int MAX_CODE = 0xffff;
105 public final static int MAX_LOCALS = 0xffff;
106 public final static int MAX_STACK = 0xffff;
107
108 public final static int PREVIEW_MINOR_VERSION = 0xffff;
109
110 public enum Version {
111 V45_3(45, 3), // base level for all attributes
112 V49(49, 0), // JDK 1.5: enum, generics, annotations
113 V50(50, 0), // JDK 1.6: stackmaps
114 V51(51, 0), // JDK 1.7
115 V52(52, 0), // JDK 1.8: lambda, type annos, param names
116 V53(53, 0), // JDK 1.9: modules, indy string concat
117 V54(54, 0), // JDK 10
118 V55(55, 0), // JDK 11: constant dynamic, nest mates
119 V56(56, 0); // JDK 12
120 Version(int major, int minor) {
121 this.major = major;
122 this.minor = minor;
123 }
124 public final int major, minor;
125
126 private static final Version MIN = values()[0];
127 /** Return the least version supported, MIN */
128 public static Version MIN() { return MIN; }
129
130 private static final Version MAX = values()[values().length-1];
131 /** Return the largest version supported, MAX */
132 public static Version MAX() { return MAX; }
133 }
134
135
136 /************************************************************************
137 * String Translation Routines
138 ***********************************************************************/
139
140 /**
141 * Return internal representation of buf[offset..offset+len-1], converting '/' to '.'.
142 *
143 * Note: the naming is the inverse of that used by JVMS 4.2 The Internal Form Of Names,
144 * which defines "internal name" to be the form using "/" instead of "."
145 */
146 public static byte[] internalize(byte[] buf, int offset, int len) {
147 byte[] translated = new byte[len];
148 for (int j = 0; j < len; j++) {
149 byte b = buf[offset + j];
150 if (b == '/') translated[j] = (byte) '.';
151 else translated[j] = b;
152 }
153 return translated;
154 }
155
156 /**
157 * Return internal representation of given name, converting '/' to '.'.
158 *
159 * Note: the naming is the inverse of that used by JVMS 4.2 The Internal Form Of Names,
160 * which defines "internal name" to be the form using "/" instead of "."
161 */
162 public static byte[] internalize(Name name) {
163 return internalize(name.getByteArray(), name.getByteOffset(), name.getByteLength());
164 }
165
166 /**
167 * Return external representation of buf[offset..offset+len-1], converting '.' to '/'.
168 *
169 * Note: the naming is the inverse of that used by JVMS 4.2 The Internal Form Of Names,
170 * which defines "internal name" to be the form using "/" instead of "."
171 */
172 public static byte[] externalize(byte[] buf, int offset, int len) {
173 byte[] translated = new byte[len];
174 for (int j = 0; j < len; j++) {
175 byte b = buf[offset + j];
176 if (b == '.') translated[j] = (byte) '/';
177 else translated[j] = b;
178 }
179 return translated;
180 }
181
182 /**
183 * Return external representation of given name, converting '/' to '.'.
184 *
185 * Note: the naming is the inverse of that used by JVMS 4.2 The Internal Form Of Names,
186 * which defines "internal name" to be the form using "/" instead of "."
187 */
188 public static byte[] externalize(Name name) {
189 return externalize(name.getByteArray(), name.getByteOffset(), name.getByteLength());
190 }
191
192 /************************************************************************
193 * Name-and-type
194 ***********************************************************************/
195
196 /** A class for the name-and-type signature of a method or field.
197 */
198 public static class NameAndType {
199 Name name;
200 UniqueType uniqueType;
201 Types types;
202
203 NameAndType(Name name, Type type, Types types) {
204 this.name = name;
205 this.uniqueType = new UniqueType(type, types);
206 this.types = types;
207 }
208
209 void setType(Type type) {
210 this.uniqueType = new UniqueType(type, types);
211 }
212
213 @Override
214 public boolean equals(Object other) {
215 return (other instanceof NameAndType &&
216 name == ((NameAndType) other).name &&
217 uniqueType.equals(((NameAndType) other).uniqueType));
218 }
219
220 @Override
221 public int hashCode() {
222 return name.hashCode() * uniqueType.hashCode();
223 }
224 }
225 }