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8289106: Add model of class file versions to core reflection

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Reviewed-by: rriggs
This commit is contained in:
Joe Darcy 2022-08-16 18:43:58 +00:00
parent c3d3662e52
commit e44e3f0c19
6 changed files with 803 additions and 44 deletions
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216
src/java.base/share/classes/java/lang/reflect/AccessFlag.java
View file

@ -28,6 +28,7 @@ package java.lang.reflect;
import java.util.Collections;
import java.util.Map;
import java.util.Set;
import java.util.function.Function;
import static java.util.Map.entry;
/**
@ -70,7 +71,7 @@ import static java.util.Map.entry;
* added at the end of the existing list.
*
* @apiNote
* The JVM class file format has a new version defined for each new
* The JVM class file format has a {@linkplain ClassFileFormatVersion new version} defined for each new
* {@linkplain Runtime.Version#feature() feature release}. A new class
* file version may define new access flags or retire old ones. {@code
* AccessFlag} is intended to model the set of access flags across
@ -97,29 +98,44 @@ public enum AccessFlag {
* <code>{@value "0x%04x" Modifier#PUBLIC}</code>.
*/
PUBLIC(Modifier.PUBLIC, true,
Set.of(Location.CLASS, Location.FIELD, Location.METHOD,
Location.INNER_CLASS)),
Location.SET_PUBLIC_1,
cffv -> {
return (cffv == ClassFileFormatVersion.RELEASE_0) ?
Location.SET_CLASS_FIELD_METHOD:
Location.SET_PUBLIC_1;
}),
/**
* The access flag {@code ACC_PRIVATE}, corresponding to the
* source modifier {@link Modifier#PRIVATE private} with a mask
* value of <code>{@value "0x%04x" Modifier#PRIVATE}</code>.
*/
PRIVATE(Modifier.PRIVATE, true, Location.SET_FIELD_METHOD_INNER_CLASS),
PRIVATE(Modifier.PRIVATE, true, Location.SET_FIELD_METHOD_INNER_CLASS,
cffv -> {
return (cffv == ClassFileFormatVersion.RELEASE_0) ?
Location.SET_FIELD_METHOD:
Location.SET_FIELD_METHOD_INNER_CLASS;
}),
/**
* The access flag {@code ACC_PROTECTED}, corresponding to the
* source modifier {@link Modifier#PROTECTED protected} with a mask
* value of <code>{@value "0x%04x" Modifier#PROTECTED}</code>.
*/
PROTECTED(Modifier.PROTECTED, true, Location.SET_FIELD_METHOD_INNER_CLASS),
PROTECTED(Modifier.PROTECTED, true, Location.SET_FIELD_METHOD_INNER_CLASS,
cffv -> {return (cffv == ClassFileFormatVersion.RELEASE_0) ?
Location.SET_FIELD_METHOD:
Location.SET_FIELD_METHOD_INNER_CLASS;}),
/**
* The access flag {@code ACC_STATIC}, corresponding to the source
* modifier {@link Modifier#STATIC static} with a mask value of
* <code>{@value "0x%04x" Modifier#STATIC}</code>.
*/
STATIC(Modifier.STATIC, true, Location.SET_FIELD_METHOD_INNER_CLASS),
STATIC(Modifier.STATIC, true, Location.SET_FIELD_METHOD_INNER_CLASS,
cffv -> {return (cffv == ClassFileFormatVersion.RELEASE_0) ?
Location.SET_FIELD_METHOD:
Location.SET_FIELD_METHOD_INNER_CLASS;}),
/**
* The access flag {@code ACC_FINAL}, corresponding to the source
@ -127,8 +143,16 @@ public enum AccessFlag {
* value of <code>{@value "0x%04x" Modifier#FINAL}</code>.
*/
FINAL(Modifier.FINAL, true,
Set.of(Location.CLASS, Location.FIELD, Location.METHOD,
Location.INNER_CLASS, Location.METHOD_PARAMETER)),
Location.SET_FINAL_8,
cffv -> {
if (cffv.compareTo(ClassFileFormatVersion.RELEASE_8) >= 0) {
return Location.SET_FINAL_8;
} else {
return (cffv == ClassFileFormatVersion.RELEASE_0) ?
Location.SET_CLASS_FIELD_METHOD :
Location.SET_CLASS_FIELD_METHOD_INNER_CLASS;
}
}),
/**
* The access flag {@code ACC_SUPER} with a mask value of {@code
@ -138,77 +162,96 @@ public enum AccessFlag {
* In Java SE 8 and above, the JVM treats the {@code ACC_SUPER}
* flag as set in every class file (JVMS {@jvms 4.1}).
*/
SUPER(0x0000_0020, false, Location.SET_CLASS),
SUPER(0x0000_0020, false, Location.SET_CLASS, null),
/**
* The module flag {@code ACC_OPEN} with a mask value of {@code
* 0x0020}.
* @see java.lang.module.ModuleDescriptor#isOpen
*/
OPEN(0x0000_0020, false, Set.of(Location.MODULE)),
OPEN(0x0000_0020, false, Location.SET_MODULE,
cffv -> { return (cffv.compareTo(ClassFileFormatVersion.RELEASE_9) >= 0 ) ?
Location.SET_MODULE:
Location.EMPTY_SET;}),
/**
* The module requires flag {@code ACC_TRANSITIVE} with a mask
* value of {@code 0x0020}.
* @see java.lang.module.ModuleDescriptor.Requires.Modifier#TRANSITIVE
*/
TRANSITIVE(0x0000_0020, false, Location.SET_MODULE_REQUIRES),
TRANSITIVE(0x0000_0020, false, Location.SET_MODULE_REQUIRES,
cffv -> {return (cffv.compareTo(ClassFileFormatVersion.RELEASE_9) >= 0 ) ?
Location.SET_MODULE_REQUIRES:
Location.EMPTY_SET;}),
/**
* The access flag {@code ACC_SYNCHRONIZED}, corresponding to the
* source modifier {@link Modifier#SYNCHRONIZED synchronized} with
* a mask value of <code>{@value "0x%04x" Modifier#SYNCHRONIZED}</code>.
*/
SYNCHRONIZED(Modifier.SYNCHRONIZED, true, Location.SET_METHOD),
SYNCHRONIZED(Modifier.SYNCHRONIZED, true, Location.SET_METHOD, null),
/**
* The module requires flag {@code ACC_STATIC_PHASE} with a mask
* value of {@code 0x0040}.
* @see java.lang.module.ModuleDescriptor.Requires.Modifier#STATIC
*/
STATIC_PHASE(0x0000_0040, false, Location.SET_MODULE_REQUIRES),
STATIC_PHASE(0x0000_0040, false, Location.SET_MODULE_REQUIRES,
cffv -> {return (cffv.compareTo(ClassFileFormatVersion.RELEASE_9) >= 0 ) ?
Location.SET_MODULE_REQUIRES:
Location.EMPTY_SET;}),
/**
* The access flag {@code ACC_VOLATILE}, corresponding to the
* source modifier {@link Modifier#VOLATILE volatile} with a mask
* value of <code>{@value "0x%04x" Modifier#VOLATILE}</code>.
*/
VOLATILE(Modifier.VOLATILE, true, Location.SET_FIELD),
/**
* The access flag {@code ACC_VOLATILE}, corresponding to the
* source modifier {@link Modifier#VOLATILE volatile} with a mask
* value of <code>{@value "0x%04x" Modifier#VOLATILE}</code>.
*/
VOLATILE(Modifier.VOLATILE, true, Location.SET_FIELD, null),
/**
* The access flag {@code ACC_BRIDGE} with a mask value of
* <code>{@value "0x%04x" Modifier#BRIDGE}</code>
* @see Method#isBridge()
*/
BRIDGE(Modifier.BRIDGE, false, Location.SET_METHOD),
BRIDGE(Modifier.BRIDGE, false, Location.SET_METHOD,
cffv -> {return (cffv.compareTo(ClassFileFormatVersion.RELEASE_5) >= 0 ) ?
Location.SET_METHOD:
Location.EMPTY_SET;}),
/**
* The access flag {@code ACC_TRANSIENT}, corresponding to the
* source modifier {@link Modifier#TRANSIENT transient} with a
* mask value of <code>{@value "0x%04x" Modifier#TRANSIENT}</code>.
*/
TRANSIENT(Modifier.TRANSIENT, true, Location.SET_FIELD),
TRANSIENT(Modifier.TRANSIENT, true, Location.SET_FIELD, null),
/**
* The access flag {@code ACC_VARARGS} with a mask value of
<code>{@value "0x%04x" Modifier#VARARGS}</code>.
* @see Executable#isVarArgs()
*/
VARARGS(Modifier.VARARGS, false, Location.SET_METHOD),
VARARGS(Modifier.VARARGS, false, Location.SET_METHOD,
cffv -> {return (cffv.compareTo(ClassFileFormatVersion.RELEASE_5) >= 0 ) ?
Location.SET_METHOD:
Location.EMPTY_SET;}),
/**
* The access flag {@code ACC_NATIVE}, corresponding to the source
* modifier {@link Modifier#NATIVE native} with a mask value of
* <code>{@value "0x%04x" Modifier#NATIVE}</code>.
*/
NATIVE(Modifier.NATIVE, true, Location.SET_METHOD),
NATIVE(Modifier.NATIVE, true, Location.SET_METHOD, null),
/**
* The access flag {@code ACC_INTERFACE} with a mask value of
* {@code 0x0200}.
* @see Class#isInterface()
*/
INTERFACE(Modifier.INTERFACE, false, Location.SET_CLASS_INNER_CLASS),
INTERFACE(Modifier.INTERFACE, false, Location.SET_CLASS_INNER_CLASS,
cffv -> { return (cffv.compareTo(ClassFileFormatVersion.RELEASE_0) == 0 ) ?
Location.SET_CLASS:
Location.SET_CLASS_INNER_CLASS;}),
/**
* The access flag {@code ACC_ABSTRACT}, corresponding to the
@ -216,7 +259,10 @@ public enum AccessFlag {
* value of <code>{@value "0x%04x" Modifier#ABSTRACT}</code>.
*/
ABSTRACT(Modifier.ABSTRACT, true,
Set.of(Location.CLASS, Location.METHOD, Location.INNER_CLASS)),
Location.SET_CLASS_METHOD_INNER_CLASS,
cffv -> { return (cffv.compareTo(ClassFileFormatVersion.RELEASE_0) == 0 ) ?
Location.SET_CLASS_METHOD:
Location.SET_CLASS_METHOD_INNER_CLASS;}),
/**
* The access flag {@code ACC_STRICT}, corresponding to the source
@ -228,7 +274,12 @@ public enum AccessFlag {
* major versions 46 through 60, inclusive (JVMS {@jvms 4.6}),
* corresponding to Java SE 1.2 through 16.
*/
STRICT(Modifier.STRICT, true, Location.SET_METHOD),
STRICT(Modifier.STRICT, true, Location.SET_METHOD,
cffv -> {return (cffv.compareTo(ClassFileFormatVersion.RELEASE_2) >= 0 &&
cffv.compareTo(ClassFileFormatVersion.RELEASE_16) <= 0) ?
Location.SET_METHOD:
Location.EMPTY_SET;}),
/**
* The access flag {@code ACC_SYNTHETIC} with a mask value of
@ -237,41 +288,63 @@ public enum AccessFlag {
* @see Executable#isSynthetic()
* @see java.lang.module.ModuleDescriptor.Modifier#SYNTHETIC
*/
SYNTHETIC(Modifier.SYNTHETIC, false,
Set.of(Location.CLASS, Location.FIELD, Location.METHOD,
Location.INNER_CLASS, Location.METHOD_PARAMETER,
Location.MODULE, Location.MODULE_REQUIRES,
Location.MODULE_EXPORTS, Location.MODULE_OPENS)),
SYNTHETIC(Modifier.SYNTHETIC, false, Location.SET_SYNTHETIC_9,
cffv -> {
if (cffv.compareTo(ClassFileFormatVersion.RELEASE_9) >= 0 )
return Location.SET_SYNTHETIC_9;
else {
return
switch(cffv) {
case RELEASE_7 -> Location.SET_SYNTHETIC_7;
case RELEASE_8 -> Location.SET_SYNTHETIC_8;
default -> Location.EMPTY_SET;
};
}
}),
/**
* The access flag {@code ACC_ANNOTATION} with a mask value of
* <code>{@value "0x%04x" Modifier#ANNOTATION}</code>.
* @see Class#isAnnotation()
*/
ANNOTATION(Modifier.ANNOTATION, false, Location.SET_CLASS_INNER_CLASS),
ANNOTATION(Modifier.ANNOTATION, false, Location.SET_CLASS_INNER_CLASS,
cffv -> {return (cffv.compareTo(ClassFileFormatVersion.RELEASE_5) >= 0 ) ?
Location.SET_CLASS_INNER_CLASS:
Location.EMPTY_SET;}),
/**
* The access flag {@code ACC_ENUM} with a mask value of
* <code>{@value "0x%04x" Modifier#ENUM}</code>.
* @see Class#isEnum()
*/
ENUM(Modifier.ENUM, false,
Set.of(Location.CLASS, Location.FIELD, Location.INNER_CLASS)),
ENUM(Modifier.ENUM, false, Location.SET_CLASS_FIELD_INNER_CLASS,
cffv -> {return (cffv.compareTo(ClassFileFormatVersion.RELEASE_5) >= 0 ) ?
Location.SET_CLASS_FIELD_INNER_CLASS:
Location.EMPTY_SET;}),
/**
* The access flag {@code ACC_MANDATED} with a mask value of
* <code>{@value "0x%04x" Modifier#MANDATED}</code>.
*/
MANDATED(Modifier.MANDATED, false,
Set.of(Location.METHOD_PARAMETER,
Location.MODULE, Location.MODULE_REQUIRES,
Location.MODULE_EXPORTS, Location.MODULE_OPENS)),
MANDATED(Modifier.MANDATED, false, Location.SET_MANDATED_9,
cffv -> {
if (cffv.compareTo(ClassFileFormatVersion.RELEASE_9) >= 0 ) {
return Location.SET_MANDATED_9;
} else {
return (cffv == ClassFileFormatVersion.RELEASE_8) ?
Location.SET_METHOD_PARAM:
Location.EMPTY_SET;
}
}),
/**
* The access flag {@code ACC_MODULE} with a mask value of {@code
* 0x8000}.
*/
MODULE(0x0000_8000, false, Location.SET_CLASS)
MODULE(0x0000_8000, false, Location.SET_CLASS,
cffv -> {return (cffv.compareTo(ClassFileFormatVersion.RELEASE_9) >= 0 ) ?
Location.SET_CLASS:
Location.EMPTY_SET;})
;
// May want to override toString for a different enum constant ->
@ -283,11 +356,17 @@ public enum AccessFlag {
// Intentionally using Set rather than EnumSet since EnumSet is
// mutable.
private final Set<Location> locations;
// Lambda to implement locations(ClassFileFormatVersion cffv)
private final Function<ClassFileFormatVersion, Set<Location>> cffvToLocations;
private AccessFlag(int mask, boolean sourceModifier, Set<Location> locations) {
private AccessFlag(int mask,
boolean sourceModifier,
Set<Location> locations,
Function<ClassFileFormatVersion, Set<Location>> cffvToLocations) {
this.mask = mask;
this.sourceModifier = sourceModifier;
this.locations = locations;
this.cffvToLocations = cffvToLocations;
}
/**
@ -306,12 +385,27 @@ public enum AccessFlag {
}
/**
* {@return kinds of constructs the flag can be applied to}
* {@return kinds of constructs the flag can be applied to in the
* latest class file format version}
*/
public Set<Location> locations() {
return locations;
}
/**
* {@return kinds of constructs the flag can be applied to in the
* given class file format version}
* @param cffv the class file format version to use
* @throws NullPointerException if the parameter is {@code null}
*/
public Set<Location> locations(ClassFileFormatVersion cffv) {
if (cffvToLocations == null) {
return locations;
} else {
return cffvToLocations.apply(cffv);
}
}
/**
* {@return an unmodifiable set of access flags for the given mask value
* appropriate for the location in question}
@ -402,15 +496,55 @@ public enum AccessFlag {
MODULE_OPENS;
// Repeated sets of locations used by AccessFlag constants
private static final Set<Location> EMPTY_SET = Set.of();
private static final Set<Location> SET_MODULE = Set.of(MODULE);
private static final Set<Location> SET_CLASS_METHOD_INNER_CLASS =
Set.of(CLASS, METHOD, INNER_CLASS);
private static final Set<Location> SET_CLASS_FIELD_METHOD =
Set.of(CLASS, FIELD, METHOD);
private static final Set<Location> SET_CLASS_FIELD_INNER_CLASS =
Set.of(CLASS, FIELD, INNER_CLASS);
private static final Set<Location> SET_CLASS_FIELD_METHOD_INNER_CLASS =
Set.of(CLASS, FIELD, METHOD, INNER_CLASS);
private static final Set<Location> SET_CLASS_METHOD =
Set.of(CLASS, METHOD);
private static final Set<Location> SET_FIELD_METHOD =
Set.of(FIELD, METHOD);
private static final Set<Location> SET_FIELD_METHOD_INNER_CLASS =
Set.of(FIELD, METHOD, INNER_CLASS);
private static final Set<Location> SET_METHOD = Set.of(METHOD);
private static final Set<Location> SET_METHOD_PARAM = Set.of(METHOD_PARAMETER);
private static final Set<Location> SET_FIELD = Set.of(FIELD);
private static final Set<Location> SET_CLASS = Set.of(CLASS);
private static final Set<Location> SET_CLASS_INNER_CLASS =
Set.of(CLASS, INNER_CLASS);
private static final Set<Location> SET_MODULE_REQUIRES =
Set.of(MODULE_REQUIRES);
private static final Set<Location> SET_PUBLIC_1 =
Set.of(CLASS, FIELD, METHOD, INNER_CLASS);
private static final Set<Location> SET_FINAL_8 =
Set.of(CLASS, FIELD, METHOD,
INNER_CLASS, /* added in 1.1 */
METHOD_PARAMETER); /* added in 8 */
private static final Set<Location> SET_SYNTHETIC_7 =
Set.of(CLASS, FIELD, METHOD,
INNER_CLASS);
private static final Set<Location> SET_SYNTHETIC_8 =
Set.of(CLASS, FIELD, METHOD,
INNER_CLASS, METHOD_PARAMETER);
private static final Set<Location> SET_SYNTHETIC_9 =
// Added as an access flag in 7
Set.of(CLASS, FIELD, METHOD,
INNER_CLASS,
METHOD_PARAMETER, // Added in 8
// Module-related items added in 9
MODULE, MODULE_REQUIRES,
MODULE_EXPORTS, MODULE_OPENS);
private static final Set<Location> SET_MANDATED_9 =
Set.of(METHOD_PARAMETER, // From 8
// Starting in 9
MODULE, MODULE_REQUIRES,
MODULE_EXPORTS, MODULE_OPENS);
}
private static class LocationToFlags {

353
src/java.base/share/classes/java/lang/reflect/ClassFileFormatVersion.java Normal file
View file

@ -0,0 +1,353 @@
/*
* Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* 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).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package java.lang.reflect;
/**
* Class file format versions of the Java virtual machine.
*
* See the appropriate edition of <cite>The Java Virtual Machine
* Specification</cite> for information about a particular class file
* format version.
*
* <p>Note that additional class file format version constants will be
* added to model future releases of the Java Virtual Machine
* Specification.
*
* @since 20
* @see System#getProperties System property {@code java.class.version}
* @see java.compiler/javax.lang.model.SourceVersion
*/
@SuppressWarnings("doclint:reference") // cross-module links
public enum ClassFileFormatVersion {
/**
* The original version.
*
* The format described in <cite>The Java Virtual Specification,
* First Edition</cite>.
*/
RELEASE_0(45),
/**
* The version recognized by the Java Platform 1.1.
*
* @apiNote
* While {@code RELEASE_0} and {@code RELEASE_1} have the same
* {@linkplain #major() major version}, several additional
* attributes were defined for {@code RELEASE_1} (JVMS {@jvms
* 4.7}).
*
*/
RELEASE_1(45),
/**
* The version recognized by the Java 2 Platform, Standard Edition,
* v 1.2.
*
* The format described in <cite>The Java Virtual Machine
* Specification, Second Edition</cite>, which includes the {@link
* AccessFlag#STRICT ACC_STRICT} access flag.
*/
RELEASE_2(46),
/**
* The version recognized by the Java 2 Platform, Standard Edition,
* v 1.3.
*/
RELEASE_3(47),
/**
* The version recognized by the Java 2 Platform, Standard Edition,
* v 1.4.
*/
RELEASE_4(48),
/**
* The version recognized by the Java 2 Platform, Standard
* Edition 5.0.
*
* @see <a
* href="https://jcp.org/aboutJava/communityprocess/maintenance/jsr924/index.html">
* <cite>The Java Virtual Machine Specification, Second Edition updated for Java SE 5.0</cite></a>
* @see <a href="https://jcp.org/en/jsr/detail?id=14">
* JSR 14: Add Generic Types To The Java&trade; Programming Language</a>
* @see <a href="https://jcp.org/en/jsr/detail?id=175">
* JSR 175: A Metadata Facility for the Java&trade; Programming Language</a>
*/
RELEASE_5(49),
/**
* The version recognized by the Java Platform, Standard Edition
* 6.
*
* @see <a
* href="https://jcp.org/aboutJava/communityprocess/maintenance/jsr924/index2.html">
* <cite>The Java Virtual Machine Specification, Java SE, Second Edition updated for Java SE 6</cite></a>
*/
RELEASE_6(50),
/**
* The version recognized by the Java Platform, Standard Edition
* 7.
*
* @see <a
* href="https://docs.oracle.com/javase/specs/jvms/se7/html/index.html">
* <cite>The Java Virtual Machine Specification, Java SE 7 Edition</cite></a>
*/
RELEASE_7(51),
/**
* The version recognized by the Java Platform, Standard Edition
* 8.
*
* @see <a
* href="https://docs.oracle.com/javase/specs/jvms/se8/html/index.html">
* <cite>The Java Virtual Machine Specification, Java SE 8 Edition</cite></a>
* @see <a href="https://jcp.org/en/jsr/detail?id=335">
* JSR 335: Lambda Expressions for the Java&trade; Programming Language</a>
*/
RELEASE_8(52),
/**
* The version recognized by the Java Platform, Standard Edition
* 9.
*
* @see <a
* href="https://docs.oracle.com/javase/specs/jvms/se9/html/index.html">
* <cite>The Java Virtual Machine Specification, Java SE 9 Edition</cite></a>
* @see <a href="https://jcp.org/en/jsr/detail?id=376">
* JSR 376: Java&trade; Platform Module System</a>
*/
RELEASE_9(53),
/**
* The version recognized by the Java Platform, Standard Edition
* 10.
*
* @see <a
* href="https://docs.oracle.com/javase/specs/jvms/se10/html/index.html">
* <cite>The Java Virtual Machine Specification, Java SE 10 Edition</cite></a>
*/
RELEASE_10(54),
/**
* The version recognized by the Java Platform, Standard Edition
* 11.
*
* @see <a
* href="https://docs.oracle.com/javase/specs/jvms/se11/html/index.html">
* <cite>The Java Virtual Machine Specification, Java SE 11 Edition</cite></a>
* @see <a href="https://openjdk.java.net/jeps/181">
* JEP 181: Nest-Based Access Control</a>
*/
RELEASE_11(55),
/**
* The version recognized by the Java Platform, Standard Edition
* 12.
*
* @see <a
* href="https://docs.oracle.com/javase/specs/jvms/se12/html/index.html">
* <cite>The Java Virtual Machine Specification, Java SE 12 Edition</cite></a>
*/
RELEASE_12(56),
/**
* The version recognized by the Java Platform, Standard Edition
* 13.
*
* @see <a
* href="https://docs.oracle.com/javase/specs/jvms/se13/html/index.html">
* <cite>The Java Virtual Machine Specification, Java SE 13 Edition</cite></a>
*/
RELEASE_13(57),
/**
* The version recognized by the Java Platform, Standard Edition
* 14.
*
* @see <a
* href="https://docs.oracle.com/javase/specs/jvms/se14/html/index.html">
* <cite>The Java Virtual Machine Specification, Java SE 14 Edition</cite></a>
*/
RELEASE_14(58),
/**
* The version recognized by the Java Platform, Standard Edition
* 15.
*
* @see <a
* href="https://docs.oracle.com/javase/specs/jvms/se15/html/index.html">
* <cite>The Java Virtual Machine Specification, Java SE 15 Edition</cite></a>
* @see <a href="https://openjdk.java.net/jeps/371">
* JEP 371: Hidden Classes</a>
*/
RELEASE_15(59),
/**
* The version recognized by the Java Platform, Standard Edition
* 16.
*
* @see <a
* href="https://docs.oracle.com/javase/specs/jvms/se16/html/index.html">
* <cite>The Java Virtual Machine Specification, Java SE 16 Edition</cite></a>
*/
RELEASE_16(60),
/**
* The version recognized by the Java Platform, Standard Edition
* 17.
*
* Additions in this release include sealed classes and
* restoration of always-strict floating-point semantics.
*
* @see <a
* href="https://docs.oracle.com/javase/specs/jvms/se17/html/index.html">
* <cite>The Java Virtual Machine Specification, Java SE 17 Edition</cite></a>
* @see <a href="https://openjdk.java.net/jeps/306">
* JEP 306: Restore Always-Strict Floating-Point Semantics</a>
* @see <a href="https://openjdk.java.net/jeps/409">
* JEP 409: Sealed Classes</a>
*/
RELEASE_17(61),
/**
* The version recognized by the Java Platform, Standard Edition
* 18.
*
* @see <a
* href="https://docs.oracle.com/javase/specs/jvms/se18/html/index.html">
* <cite>The Java Virtual Machine Specification, Java SE 18 Edition</cite></a>
*/
RELEASE_18(62),
/**
* The version recognized by the Java Platform, Standard Edition
* 19.
*/
RELEASE_19(63),
/**
* The version recognized by the Java Platform, Standard Edition
* 20.
*/
RELEASE_20(64);
// Note to maintainers: when adding constants for newer releases,
// the implementation of latest() must be updated too.
private final int major;
private ClassFileFormatVersion(int major) {
this.major = major;
}
/**
* {@return the latest class file format version}
*/
public static ClassFileFormatVersion latest() {
return RELEASE_20;
}
/**
* {@return the major class file version as an integer}
* @jvms 4.1 The {@code ClassFile} Structure
*/
public int major() {
return major;
}
/**
* {@return the latest class file format version that is usable
* under the runtime version argument} If the runtime version's
* {@linkplain Runtime.Version#feature() feature} is greater than
* the feature of the {@linkplain #runtimeVersion() runtime
* version} of the {@linkplain #latest() latest class file format
* version}, an {@code IllegalArgumentException} is thrown.
*
* <p>Because the class file format versions of the Java platform
* have so far followed a linear progression, only the feature
* component of a runtime version is queried to determine the
* mapping to a class file format version. If that linearity
* changes in the future, other components of the runtime version
* may influence the result.
*
* @apiNote
* An expression to convert from a string value, for example
* {@code "17"}, to the corresponding class file format version,
* {@code RELEASE_17}, is:
*
* {@snippet lang="java" :
* ClassFileFormatVersion.valueOf(Runtime.Version.parse("17"))}
*
* @param rv runtime version to map to a class file format version
* @throws IllegalArgumentException if the feature of version
* argument is greater than the feature of the platform version.
*/
public static ClassFileFormatVersion valueOf(Runtime.Version rv) {
// Could also implement this as a switch where a case was
// added with each new release.
return valueOf("RELEASE_" + rv.feature());
}
/**
* {@return the least runtime version that supports this class
* file format version; otherwise {@code null}} The returned
* runtime version has a {@linkplain Runtime.Version#feature()
* feature} large enough to support this class file format version
* and has no other elements set.
*
* Class file format versions greater than or equal to {@link
* RELEASE_6} have non-{@code null} results.
*/
public Runtime.Version runtimeVersion() {
// Starting with Java SE 6, the leading digit was the primary
// way of identifying the platform version.
if (this.compareTo(RELEASE_6) >= 0) {
return Runtime.Version.parse(Integer.toString(ordinal()));
} else {
return null;
}
}
/**
* {@return the latest class file format version whose major class
* file version matches the argument}
* @param major the major class file version as an integer
* @throws IllegalArgumentException if the argument is outside of
* the range of major class file versions
*/
public static ClassFileFormatVersion fromMajor(int major) {
if (major < 45 // RELEASE_0.major()
|| major > latest().major()) {
throw new IllegalArgumentException("Out of range major class file vesion "
+ major);
}
// RELEASE_0 and RELEASE_1 both have a major version of 45;
// return RELEASE_1 for an argument of 45.
return values()[major-44];
}
}