ClassFile.java revision 3388:b42e6d7b1b99
1/* 2 * Copyright (c) 1999, 2016, 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 26package com.sun.tools.javac.jvm; 27 28import com.sun.tools.javac.code.Type; 29import com.sun.tools.javac.code.Types; 30import com.sun.tools.javac.code.Types.UniqueType; 31import 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> */ 68public 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_InvokeDynamic = 18; 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 enum Version { 106 V45_3(45, 3), // base level for all attributes 107 V49(49, 0), // JDK 1.5: enum, generics, annotations 108 V50(50, 0), // JDK 1.6: stackmaps 109 V51(51, 0), // JDK 1.7 110 V52(52, 0), // JDK 1.8: lambda, type annos, param names 111 V53(53, 0); // JDK 1.9: modules, indy string concat 112 Version(int major, int minor) { 113 this.major = major; 114 this.minor = minor; 115 } 116 public final int major, minor; 117 118 private static final Version MIN = values()[0]; 119 /** Return the least version supported, MIN */ 120 public static Version MIN() { return MIN; } 121 122 private static final Version MAX = values()[values().length-1]; 123 /** Return the largest version supported, MAX */ 124 public static Version MAX() { return MAX; } 125 } 126 127 128/************************************************************************ 129 * String Translation Routines 130 ***********************************************************************/ 131 132 /** Return internal representation of buf[offset..offset+len-1], 133 * converting '/' to '.'. 134 */ 135 public static byte[] internalize(byte[] buf, int offset, int len) { 136 byte[] translated = new byte[len]; 137 for (int j = 0; j < len; j++) { 138 byte b = buf[offset + j]; 139 if (b == '/') translated[j] = (byte) '.'; 140 else translated[j] = b; 141 } 142 return translated; 143 } 144 145 /** Return internal representation of given name, 146 * converting '/' to '.'. 147 */ 148 public static byte[] internalize(Name name) { 149 return internalize(name.getByteArray(), name.getByteOffset(), name.getByteLength()); 150 } 151 152 /** Return external representation of buf[offset..offset+len-1], 153 * converting '.' to '/'. 154 */ 155 public static byte[] externalize(byte[] buf, int offset, int len) { 156 byte[] translated = new byte[len]; 157 for (int j = 0; j < len; j++) { 158 byte b = buf[offset + j]; 159 if (b == '.') translated[j] = (byte) '/'; 160 else translated[j] = b; 161 } 162 return translated; 163 } 164 165 /** Return external representation of given name, 166 * converting '/' to '.'. 167 */ 168 public static byte[] externalize(Name name) { 169 return externalize(name.getByteArray(), name.getByteOffset(), name.getByteLength()); 170 } 171 172/************************************************************************ 173 * Name-and-type 174 ***********************************************************************/ 175 176 /** A class for the name-and-type signature of a method or field. 177 */ 178 public static class NameAndType { 179 Name name; 180 UniqueType uniqueType; 181 Types types; 182 183 NameAndType(Name name, Type type, Types types) { 184 this.name = name; 185 this.uniqueType = new UniqueType(type, types); 186 this.types = types; 187 } 188 189 void setType(Type type) { 190 this.uniqueType = new UniqueType(type, types); 191 } 192 193 @Override 194 public boolean equals(Object other) { 195 return (other instanceof NameAndType && 196 name == ((NameAndType) other).name && 197 uniqueType.equals(((NameAndType) other).uniqueType)); 198 } 199 200 @Override 201 public int hashCode() { 202 return name.hashCode() * uniqueType.hashCode(); 203 } 204 } 205} 206