ClassFile.java revision 2571:10fc81ac75b4
1/* 2 * Copyright (c) 1999, 2014, 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 // JDK9 still marked as V52 // V53(53, 0); // JDK 1.9 112 113 Version(int major, int minor) { 114 this.major = major; 115 this.minor = minor; 116 } 117 public final int major, minor; 118 119 private static final Version MIN = values()[0]; 120 /** Return the least version supported, MIN */ 121 public static Version MIN() { return MIN; } 122 123 private static final Version MAX = values()[values().length-1]; 124 /** Return the largest version supported, MAX */ 125 public static Version MAX() { return MAX; } 126 } 127 128 129/************************************************************************ 130 * String Translation Routines 131 ***********************************************************************/ 132 133 /** Return internal representation of buf[offset..offset+len-1], 134 * converting '/' to '.'. 135 */ 136 public static byte[] internalize(byte[] buf, int offset, int len) { 137 byte[] translated = new byte[len]; 138 for (int j = 0; j < len; j++) { 139 byte b = buf[offset + j]; 140 if (b == '/') translated[j] = (byte) '.'; 141 else translated[j] = b; 142 } 143 return translated; 144 } 145 146 /** Return internal representation of given name, 147 * converting '/' to '.'. 148 */ 149 public static byte[] internalize(Name name) { 150 return internalize(name.getByteArray(), name.getByteOffset(), name.getByteLength()); 151 } 152 153 /** Return external representation of buf[offset..offset+len-1], 154 * converting '.' to '/'. 155 */ 156 public static byte[] externalize(byte[] buf, int offset, int len) { 157 byte[] translated = new byte[len]; 158 for (int j = 0; j < len; j++) { 159 byte b = buf[offset + j]; 160 if (b == '.') translated[j] = (byte) '/'; 161 else translated[j] = b; 162 } 163 return translated; 164 } 165 166 /** Return external representation of given name, 167 * converting '/' to '.'. 168 */ 169 public static byte[] externalize(Name name) { 170 return externalize(name.getByteArray(), name.getByteOffset(), name.getByteLength()); 171 } 172 173/************************************************************************ 174 * Name-and-type 175 ***********************************************************************/ 176 177 /** A class for the name-and-type signature of a method or field. 178 */ 179 public static class NameAndType { 180 Name name; 181 UniqueType uniqueType; 182 Types types; 183 184 NameAndType(Name name, Type type, Types types) { 185 this.name = name; 186 this.uniqueType = new UniqueType(type, types); 187 this.types = types; 188 } 189 190 void setType(Type type) { 191 this.uniqueType = new UniqueType(type, types); 192 } 193 194 @Override 195 public boolean equals(Object other) { 196 return (other instanceof NameAndType && 197 name == ((NameAndType) other).name && 198 uniqueType.equals(((NameAndType) other).uniqueType)); 199 } 200 201 @Override 202 public int hashCode() { 203 return name.hashCode() * uniqueType.hashCode(); 204 } 205 } 206} 207