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 * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
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package com.sun.tools.javac.jvm;

import com.sun.tools.javac.code.Type;
import com.sun.tools.javac.code.Types;
import com.sun.tools.javac.code.Types.UniqueType;
import com.sun.tools.javac.util.Name;


A JVM class file.

Generic Java classfiles have one additional attribute for classes, methods and fields:

  "Signature" (u4 attr-length, u2 signature-index)
 

A signature gives the full Java type of a method or field. When used as a class attribute, it indicates type parameters, followed by supertype, followed by all interfaces.

    methodOrFieldSignature ::= type
    classSignature         ::= [ typeparams ] supertype { interfacetype }
 

The type syntax in signatures is extended as follows:

    type       ::= ... | classtype | methodtype | typevar
    classtype  ::= classsig { '.' classsig }
    classig    ::= 'L' name [typeargs] ';'
    methodtype ::= [ typeparams ] '(' { type } ')' type
    typevar    ::= 'T' name ';'
    typeargs   ::= '<' type { type } '>'
    typeparams ::= '<' typeparam { typeparam } '>'
    typeparam  ::= name ':' type
 

This class defines constants used in class files as well as routines to convert between internal ``.'' and external ``/'' separators in class names.

This is NOT part of any supported API. If you write code that depends on this, you do so at your own risk. This code and its internal interfaces are subject to change or deletion without notice.

/** A JVM class file. * * <p>Generic Java classfiles have one additional attribute for classes, * methods and fields: * <pre> * "Signature" (u4 attr-length, u2 signature-index) * </pre> * * <p>A signature gives the full Java type of a method or field. When * used as a class attribute, it indicates type parameters, followed * by supertype, followed by all interfaces. * <pre> * methodOrFieldSignature ::= type * classSignature ::= [ typeparams ] supertype { interfacetype } * </pre> * <p>The type syntax in signatures is extended as follows: * <pre>{@literal * type ::= ... | classtype | methodtype | typevar * classtype ::= classsig { '.' classsig } * classig ::= 'L' name [typeargs] ';' * methodtype ::= [ typeparams ] '(' { type } ')' type * typevar ::= 'T' name ';' * typeargs ::= '<' type { type } '>' * typeparams ::= '<' typeparam { typeparam } '>' * typeparam ::= name ':' type * }</pre> * <p>This class defines constants used in class files as well * as routines to convert between internal ``.'' and external ``/'' * separators in class names. * * <p><b>This is NOT part of any supported API. * If you write code that depends on this, you do so at your own risk. * This code and its internal interfaces are subject to change or * deletion without notice.</b> */
public class ClassFile { public final static int JAVA_MAGIC = 0xCAFEBABE; // see Target public final static int CONSTANT_Utf8 = 1; public final static int CONSTANT_Unicode = 2; public final static int CONSTANT_Integer = 3; public final static int CONSTANT_Float = 4; public final static int CONSTANT_Long = 5; public final static int CONSTANT_Double = 6; public final static int CONSTANT_Class = 7; public final static int CONSTANT_String = 8; public final static int CONSTANT_Fieldref = 9; public final static int CONSTANT_Methodref = 10; public final static int CONSTANT_InterfaceMethodref = 11; public final static int CONSTANT_NameandType = 12; public final static int CONSTANT_MethodHandle = 15; public final static int CONSTANT_MethodType = 16; public final static int CONSTANT_Dynamic = 17; public final static int CONSTANT_InvokeDynamic = 18; public final static int CONSTANT_Module = 19; public final static int CONSTANT_Package = 20; public final static int REF_getField = 1; public final static int REF_getStatic = 2; public final static int REF_putField = 3; public final static int REF_putStatic = 4; public final static int REF_invokeVirtual = 5; public final static int REF_invokeStatic = 6; public final static int REF_invokeSpecial = 7; public final static int REF_newInvokeSpecial = 8; public final static int REF_invokeInterface = 9; public final static int MAX_PARAMETERS = 0xff; public final static int MAX_DIMENSIONS = 0xff; public final static int MAX_CODE = 0xffff; public final static int MAX_LOCALS = 0xffff; public final static int MAX_STACK = 0xffff; public final static int PREVIEW_MINOR_VERSION = 0xffff; public enum Version { V45_3(45, 3), // base level for all attributes V49(49, 0), // JDK 1.5: enum, generics, annotations V50(50, 0), // JDK 1.6: stackmaps V51(51, 0), // JDK 1.7 V52(52, 0), // JDK 1.8: lambda, type annos, param names V53(53, 0), // JDK 1.9: modules, indy string concat V54(54, 0), // JDK 10 V55(55, 0), // JDK 11: constant dynamic, nest mates V56(56, 0); // JDK 12 Version(int major, int minor) { this.major = major; this.minor = minor; } public final int major, minor; private static final Version MIN = values()[0];
Return the least version supported, MIN
/** Return the least version supported, MIN */
public static Version MIN() { return MIN; } private static final Version MAX = values()[values().length-1];
Return the largest version supported, MAX
/** Return the largest version supported, MAX */
public static Version MAX() { return MAX; } } /************************************************************************ * String Translation Routines ***********************************************************************/
Return internal representation of buf[offset..offset+len-1], converting '/' to '.'. Note: the naming is the inverse of that used by JVMS 4.2 The Internal Form Of Names, which defines "internal name" to be the form using "/" instead of "."
/** * Return internal representation of buf[offset..offset+len-1], converting '/' to '.'. * * Note: the naming is the inverse of that used by JVMS 4.2 The Internal Form Of Names, * which defines "internal name" to be the form using "/" instead of "." */
public static byte[] internalize(byte[] buf, int offset, int len) { byte[] translated = new byte[len]; for (int j = 0; j < len; j++) { byte b = buf[offset + j]; if (b == '/') translated[j] = (byte) '.'; else translated[j] = b; } return translated; }
Return internal representation of given name, converting '/' to '.'. Note: the naming is the inverse of that used by JVMS 4.2 The Internal Form Of Names, which defines "internal name" to be the form using "/" instead of "."
/** * Return internal representation of given name, converting '/' to '.'. * * Note: the naming is the inverse of that used by JVMS 4.2 The Internal Form Of Names, * which defines "internal name" to be the form using "/" instead of "." */
public static byte[] internalize(Name name) { return internalize(name.getByteArray(), name.getByteOffset(), name.getByteLength()); }
Return external representation of buf[offset..offset+len-1], converting '.' to '/'. Note: the naming is the inverse of that used by JVMS 4.2 The Internal Form Of Names, which defines "internal name" to be the form using "/" instead of "."
/** * Return external representation of buf[offset..offset+len-1], converting '.' to '/'. * * Note: the naming is the inverse of that used by JVMS 4.2 The Internal Form Of Names, * which defines "internal name" to be the form using "/" instead of "." */
public static byte[] externalize(byte[] buf, int offset, int len) { byte[] translated = new byte[len]; for (int j = 0; j < len; j++) { byte b = buf[offset + j]; if (b == '.') translated[j] = (byte) '/'; else translated[j] = b; } return translated; }
Return external representation of given name, converting '/' to '.'. Note: the naming is the inverse of that used by JVMS 4.2 The Internal Form Of Names, which defines "internal name" to be the form using "/" instead of "."
/** * Return external representation of given name, converting '/' to '.'. * * Note: the naming is the inverse of that used by JVMS 4.2 The Internal Form Of Names, * which defines "internal name" to be the form using "/" instead of "." */
public static byte[] externalize(Name name) { return externalize(name.getByteArray(), name.getByteOffset(), name.getByteLength()); } /************************************************************************ * Name-and-type ***********************************************************************/
A class for the name-and-type signature of a method or field.
/** A class for the name-and-type signature of a method or field. */
public static class NameAndType { Name name; UniqueType uniqueType; Types types; NameAndType(Name name, Type type, Types types) { this.name = name; this.uniqueType = new UniqueType(type, types); this.types = types; } void setType(Type type) { this.uniqueType = new UniqueType(type, types); } @Override public boolean equals(Object other) { return (other instanceof NameAndType && name == ((NameAndType) other).name && uniqueType.equals(((NameAndType) other).uniqueType)); } @Override public int hashCode() { return name.hashCode() * uniqueType.hashCode(); } } }