1 /*
2 * Copyright (c) 1999, 2019, 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.util.Name;
29
30
31 /** A JVM class file.
32 *
33 * <p>Generic Java classfiles have one additional attribute for classes,
34 * methods and fields:
35 * <pre>
36 * "Signature" (u4 attr-length, u2 signature-index)
37 * </pre>
38 *
39 * <p>A signature gives the full Java type of a method or field. When
40 * used as a class attribute, it indicates type parameters, followed
41 * by supertype, followed by all interfaces.
42 * <pre>
43 * methodOrFieldSignature ::= type
44 * classSignature ::= [ typeparams ] supertype { interfacetype }
45 * </pre>
46 * <p>The type syntax in signatures is extended as follows:
47 * <pre>{@literal
48 * type ::= ... | classtype | methodtype | typevar
49 * classtype ::= classsig { '.' classsig }
50 * classig ::= 'L' name [typeargs] ';'
51 * methodtype ::= [ typeparams ] '(' { type } ')' type
52 * typevar ::= 'T' name ';'
53 * typeargs ::= '<' type { type } '>'
54 * typeparams ::= '<' typeparam { typeparam } '>'
55 * typeparam ::= name ':' type
56 * }</pre>
57 * <p>This class defines constants used in class files as well
58 * as routines to convert between internal ``.'' and external ``/''
59 * separators in class names.
60 *
61 * <p><b>This is NOT part of any supported API.
62 * If you write code that depends on this, you do so at your own risk.
63 * This code and its internal interfaces are subject to change or
64 * deletion without notice.</b> */
65 public class ClassFile {
66
67 public final static int JAVA_MAGIC = 0xCAFEBABE;
68
69 // see Target
70 public final static int CONSTANT_Utf8 = 1;
71 public final static int CONSTANT_Unicode = 2;
72 public final static int CONSTANT_Integer = 3;
73 public final static int CONSTANT_Float = 4;
74 public final static int CONSTANT_Long = 5;
75 public final static int CONSTANT_Double = 6;
76 public final static int CONSTANT_Class = 7;
77 public final static int CONSTANT_String = 8;
78 public final static int CONSTANT_Fieldref = 9;
79 public final static int CONSTANT_Methodref = 10;
80 public final static int CONSTANT_InterfaceMethodref = 11;
81 public final static int CONSTANT_NameandType = 12;
82 public final static int CONSTANT_MethodHandle = 15;
83 public final static int CONSTANT_MethodType = 16;
84 public final static int CONSTANT_Dynamic = 17;
85 public final static int CONSTANT_InvokeDynamic = 18;
86 public final static int CONSTANT_Module = 19;
87 public final static int CONSTANT_Package = 20;
88
89 public final static int REF_getField = 1;
90 public final static int REF_getStatic = 2;
91 public final static int REF_putField = 3;
92 public final static int REF_putStatic = 4;
93 public final static int REF_invokeVirtual = 5;
94 public final static int REF_invokeStatic = 6;
95 public final static int REF_invokeSpecial = 7;
96 public final static int REF_newInvokeSpecial = 8;
97 public final static int REF_invokeInterface = 9;
98
99 public final static int MAX_PARAMETERS = 0xff;
100 public final static int MAX_DIMENSIONS = 0xff;
101 public final static int MAX_CODE = 0xffff;
102 public final static int MAX_LOCALS = 0xffff;
103 public final static int MAX_STACK = 0xffff;
104
105 public final static int PREVIEW_MINOR_VERSION = 0xffff;
106
107 public enum Version {
108 V45_3(45, 3), // base level for all attributes
109 V49(49, 0), // JDK 1.5: enum, generics, annotations
110 V50(50, 0), // JDK 1.6: stackmaps
111 V51(51, 0), // JDK 1.7
112 V52(52, 0), // JDK 1.8: lambda, type annos, param names
113 V53(53, 0), // JDK 1.9: modules, indy string concat
114 V54(54, 0), // JDK 10
115 V55(55, 0), // JDK 11: constant dynamic, nest mates
116 V56(56, 0), // JDK 12
117 V57(57, 0), // JDK 13
118 V58(58, 0), // JDK 14
119 V59(59, 0), // JDK 15
120 V60(60, 0); // JDK 16
121 Version(int major, int minor) {
122 this.major = major;
123 this.minor = minor;
124 }
125 public final int major, minor;
126
127 private static final Version MIN = values()[0];
128 /** Return the least version supported, MIN */
129 public static Version MIN() { return MIN; }
130
131 private static final Version MAX = values()[values().length-1];
132 /** Return the largest version supported, MAX */
133 public static Version MAX() { return MAX; }
134 }
135
136
137 /************************************************************************
138 * String Translation Routines
139 ***********************************************************************/
140
141 /**
142 * Return internal representation of buf[offset..offset+len-1], converting '/' to '.'.
143 *
144 * Note: the naming is the inverse of that used by JVMS 4.2 The Internal Form Of Names,
145 * which defines "internal name" to be the form using "/" instead of "."
146 */
147 public static byte[] internalize(byte[] buf, int offset, int len) {
148 byte[] translated = new byte[len];
149 for (int j = 0; j < len; j++) {
150 byte b = buf[offset + j];
151 if (b == '/') translated[j] = (byte) '.';
152 else translated[j] = b;
153 }
154 return translated;
155 }
156
157 /**
158 * Return internal representation of given name, converting '/' to '.'.
159 *
160 * Note: the naming is the inverse of that used by JVMS 4.2 The Internal Form Of Names,
161 * which defines "internal name" to be the form using "/" instead of "."
162 */
163 public static byte[] internalize(Name name) {
164 return internalize(name.getByteArray(), name.getByteOffset(), name.getByteLength());
165 }
166
167 /**
168 * Return external representation of buf[offset..offset+len-1], converting '.' to '/'.
169 *
170 * Note: the naming is the inverse of that used by JVMS 4.2 The Internal Form Of Names,
171 * which defines "internal name" to be the form using "/" instead of "."
172 */
173 public static byte[] externalize(byte[] buf, int offset, int len) {
174 byte[] translated = new byte[len];
175 for (int j = 0; j < len; j++) {
176 byte b = buf[offset + j];
177 if (b == '.') translated[j] = (byte) '/';
178 else translated[j] = b;
179 }
180 return translated;
181 }
182
183 /**
184 * Return external representation of given name, converting '/' to '.'.
185 *
186 * Note: the naming is the inverse of that used by JVMS 4.2 The Internal Form Of Names,
187 * which defines "internal name" to be the form using "/" instead of "."
188 */
189 public static byte[] externalize(Name name) {
190 return externalize(name.getByteArray(), name.getByteOffset(), name.getByteLength());
191 }
192 }