1 /* 2 * Copyright (c) 1999, 2020, 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 Version(int major, int minor)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 */ 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 */ 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 */ internalize(byte[] buf, int offset, int len)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 */ internalize(Name name)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 */ externalize(byte[] buf, int offset, int len)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 */ externalize(Name name)189 public static byte[] externalize(Name name) { 190 return externalize(name.getByteArray(), name.getByteOffset(), name.getByteLength()); 191 } 192 } 193