2025-05-01 14:37:26 +00:00

833 lines
34 KiB
Java

/*
* Copyright (c) 2021, 2025, 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;
import java.lang.classfile.ClassModel;
import java.lang.classfile.FieldModel;
import java.lang.classfile.MethodModel;
import java.lang.classfile.attribute.InnerClassInfo;
import java.lang.classfile.attribute.MethodParameterInfo;
import java.lang.classfile.attribute.ModuleAttribute;
import java.lang.classfile.attribute.ModuleExportInfo;
import java.lang.classfile.attribute.ModuleOpenInfo;
import java.lang.classfile.attribute.ModuleRequireInfo;
import java.lang.module.ModuleDescriptor;
import java.util.AbstractSet;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Objects;
import java.util.Set;
import java.util.function.Consumer;
import java.util.function.Predicate;
import jdk.internal.vm.annotation.Stable;
import static java.lang.classfile.ClassFile.*;
import static java.lang.reflect.ClassFileFormatVersion.*;
/**
* Represents a JVM access or module-related flag on a runtime member,
* such as a {@linkplain Class class}, {@linkplain Field field}, or
* {@linkplain Executable method}.
*
* <P>JVM access and module-related flags are related to, but distinct
* from Java language {@linkplain Modifier modifiers}. Some modifiers
* and access flags have a one-to-one correspondence, such as {@code
* public}. In other cases, some language-level modifiers do
* <em>not</em> have an access flag, such as {@code sealed} (JVMS
* {@jvms 4.7.31}) and some access flags have no corresponding
* modifier, such as {@linkplain #SYNTHETIC synthetic}.
*
* <p>The values for the constants representing the access and module
* flags are taken from sections of <cite>The Java Virtual Machine
* Specification</cite> including {@jvms 4.1} (class access and
* property modifiers), {@jvms 4.5} (field access and property flags),
* {@jvms 4.6} (method access and property flags), {@jvms 4.7.6}
* (nested class access and property flags), {@jvms 4.7.24} (method
* parameters), and {@jvms 4.7.25} (module flags and requires,
* exports, and opens flags).
*
* <p>The {@linkplain #mask() mask} values for the different access
* flags are <em>not</em> distinct. Flags are defined for different
* kinds of JVM structures and the same bit position has different
* meanings in different contexts. For example, {@code 0x0000_0040}
* indicates a {@link #VOLATILE volatile} field but a {@linkplain
* #BRIDGE bridge method}; {@code 0x0000_0080} indicates a {@link
* #TRANSIENT transient} field but a {@linkplain #VARARGS variable
* arity (varargs)} method.
*
* @implSpec
* The access flag constants are ordered by non-decreasing mask
* value; that is the mask value of a constant is greater than or
* equal to the mask value of an immediate neighbor to its (syntactic)
* left. If new constants are added, this property will be
* maintained. That implies new constants will not necessarily be
* added at the end of the existing list.
*
* @apiNote
* 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
* class file format versions. The range of versions an access flag is
* recognized is not explicitly indicated in this API. See the current
* <cite>The Java Virtual Machine Specification</cite> for
* details. Unless otherwise indicated, access flags can be assumed to
* be recognized in the {@linkplain Runtime#version() current
* version}.
*
* @see java.lang.reflect.Modifier
* @see java.lang.module.ModuleDescriptor.Modifier
* @see java.lang.module.ModuleDescriptor.Requires.Modifier
* @see java.lang.module.ModuleDescriptor.Exports.Modifier
* @see java.lang.module.ModuleDescriptor.Opens.Modifier
* @see java.compiler/javax.lang.model.element.Modifier
* @since 20
*/
@SuppressWarnings("doclint:reference") // cross-module link
public enum AccessFlag {
/**
* The access flag {@code ACC_PUBLIC}, corresponding to the source
* modifier {@link Modifier#PUBLIC public}, with a mask value of
* <code>{@value "0x%04x" Modifier#PUBLIC}</code>.
*/
PUBLIC(Modifier.PUBLIC, true,
Location.SET_CLASS_FIELD_METHOD_INNER_CLASS,
List.of(Map.entry(RELEASE_0, Location.SET_CLASS_FIELD_METHOD))),
/**
* 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,
List.of(Map.entry(RELEASE_0, Location.SET_FIELD_METHOD))),
/**
* 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,
List.of(Map.entry(RELEASE_0, Location.SET_FIELD_METHOD))),
/**
* 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,
List.of(Map.entry(RELEASE_0, Location.SET_FIELD_METHOD))),
/**
* The access flag {@code ACC_FINAL}, corresponding to the source
* modifier {@link Modifier#FINAL final}, with a mask
* value of <code>{@value "0x%04x" Modifier#FINAL}</code>.
*/
FINAL(Modifier.FINAL, true,
Location.SET_FINAL_8,
List.of(Map.entry(RELEASE_7, Location.SET_CLASS_FIELD_METHOD_INNER_CLASS),
Map.entry(RELEASE_0, Location.SET_CLASS_FIELD_METHOD))),
/**
* The access flag {@code ACC_SUPER} with a mask value of {@code
* 0x0020}.
*
* @apiNote
* 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, List.of()),
/**
* The module flag {@code ACC_OPEN} with a mask value of {@code
* 0x0020}.
* @see java.lang.module.ModuleDescriptor#isOpen
*/
OPEN(0x0000_0020, false, Location.SET_MODULE,
List.of(Map.entry(RELEASE_8, 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,
List.of(Map.entry(RELEASE_8, 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, List.of()),
/**
* 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,
List.of(Map.entry(RELEASE_8, 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, List.of()),
/**
* 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,
List.of(Map.entry(RELEASE_4, 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, List.of()),
/**
* 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,
List.of(Map.entry(RELEASE_4, 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, List.of()),
/**
* 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,
List.of(Map.entry(RELEASE_0, Location.SET_CLASS))),
/**
* The access flag {@code ACC_ABSTRACT}, corresponding to the
* source modifier {@link Modifier#ABSTRACT abstract}, with a mask
* value of <code>{@value "0x%04x" Modifier#ABSTRACT}</code>.
*/
ABSTRACT(Modifier.ABSTRACT, true,
Location.SET_CLASS_METHOD_INNER_CLASS,
List.of(Map.entry(RELEASE_0, Location.SET_CLASS_METHOD))),
/**
* The access flag {@code ACC_STRICT}, corresponding to the source
* modifier {@link Modifier#STRICT strictfp}, with a mask value of
* <code>{@value "0x%04x" Modifier#STRICT}</code>.
*
* @apiNote
* The {@code ACC_STRICT} access flag is defined for class file
* major versions 46 through 60, inclusive (JVMS {@jvms 4.6}),
* corresponding to Java SE 1.2 through 16.
*/
STRICT(Modifier.STRICT, true, Location.EMPTY_SET,
List.of(Map.entry(RELEASE_16, Location.SET_METHOD),
Map.entry(RELEASE_1, Location.EMPTY_SET))),
/**
* The access flag {@code ACC_SYNTHETIC} with a mask value of
* <code>{@value "0x%04x" Modifier#SYNTHETIC}</code>.
* @see Class#isSynthetic()
* @see Executable#isSynthetic()
* @see java.lang.module.ModuleDescriptor.Modifier#SYNTHETIC
*/
SYNTHETIC(Modifier.SYNTHETIC, false, Location.SET_SYNTHETIC_9,
List.of(Map.entry(RELEASE_8, Location.SET_SYNTHETIC_8),
Map.entry(RELEASE_7, Location.SET_SYNTHETIC_5),
Map.entry(RELEASE_4, 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,
List.of(Map.entry(RELEASE_4, 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, Location.SET_CLASS_FIELD_INNER_CLASS,
List.of(Map.entry(RELEASE_4, 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, Location.SET_MANDATED_9,
List.of(Map.entry(RELEASE_8, Location.SET_METHOD_PARAM),
Map.entry(RELEASE_7, Location.EMPTY_SET))),
/**
* The access flag {@code ACC_MODULE} with a mask value of {@code
* 0x8000}.
*/
MODULE(0x0000_8000, false, Location.SET_CLASS,
List.of(Map.entry(RELEASE_8, Location.EMPTY_SET))),
;
// May want to override toString for a different enum constant ->
// name mapping.
private final int mask;
private final boolean sourceModifier;
// immutable
private final Set<Location> locations;
// historical locations up to a given version; immutable
private final List<Map.Entry<ClassFileFormatVersion, Set<Location>>> historicalLocations;
private AccessFlag(int mask,
boolean sourceModifier,
Set<Location> locations,
List<Map.Entry<ClassFileFormatVersion, Set<Location>>> historicalLocations) {
this.mask = mask;
this.sourceModifier = sourceModifier;
this.locations = locations;
this.historicalLocations = Location.ensureHistoryOrdered(historicalLocations);
}
/**
* {@return the corresponding mask for the access flag} The mask has
* exactly one bit set and is in the range of {@code char}.
*/
public int mask() {
return mask;
}
/**
* {@return whether or not this flag has a directly corresponding
* modifier in the Java programming language}
*/
public boolean sourceModifier() {
return sourceModifier;
}
/**
* {@return locations this flag can be applied to in the current class file
* format version}
* <p>
* This method returns an empty set if this flag is not defined in
* the current class file format version.
*/
public Set<Location> locations() {
return locations;
}
/**
* {@return locations this flag can be applied to in the given class file
* format version}
* <p>
* This method returns an empty set if this flag is not defined in
* the given {@code cffv}.
*
* @param cffv the class file format version to use
* @throws NullPointerException if the parameter is {@code null}
*/
public Set<Location> locations(ClassFileFormatVersion cffv) {
return Location.findInHistory(locations, historicalLocations, cffv);
}
/**
* {@return an unmodifiable set of access flags for the given mask value
* appropriate for the location in the current class file format version}
*
* @param mask bit mask of access flags
* @param location context to interpret mask value
* @throws IllegalArgumentException if the mask contains bit
* positions not defined for the location in the current class file format
* @throws NullPointerException if {@code location} is {@code null}
*/
public static Set<AccessFlag> maskToAccessFlags(int mask, Location location) {
var definition = findDefinition(location); // null checks location
int unmatchedMask = mask & (~location.flagsMask());
if (unmatchedMask != 0) {
throw new IllegalArgumentException("Unmatched bit position 0x" +
Integer.toHexString(unmatchedMask) +
" for location " + location);
}
return new AccessFlagSet(definition, mask);
}
/**
* {@return an unmodifiable set of access flags for the given mask value
* appropriate for the location in the given class file format version}
*
* @param mask bit mask of access flags
* @param location context to interpret mask value
* @param cffv the class file format to interpret mask value
* @throws IllegalArgumentException if the mask contains bit
* positions not defined for the location in the given class file format
* @throws NullPointerException if {@code location} or {@code cffv} is {@code null}
* @since 25
*/
public static Set<AccessFlag> maskToAccessFlags(int mask, Location location, ClassFileFormatVersion cffv) {
var definition = findDefinition(location); // null checks location
int unmatchedMask = mask & (~location.flagsMask(cffv)); // null checks cffv
if (unmatchedMask != 0) {
throw new IllegalArgumentException("Unmatched bit position 0x" +
Integer.toHexString(unmatchedMask) +
" for location " + location +
" for class file format " + cffv);
}
return new AccessFlagSet(definition, mask);
}
/**
* A location within a {@code class} file where flags can be applied.
* <p>
* Note that since these locations represent {@code class} file structures
* rather than language structures, many language structures, such
* as constructors and interfaces, are <em>not</em> present.
* @since 20
*/
public enum Location {
/**
* Class location.
*
* @see Class#accessFlags()
* @see ClassModel#flags()
* @see Modifier#classModifiers()
* @see Modifier#interfaceModifiers()
* @jvms 4.1 The {@code ClassFile} Structure
*/
CLASS(ACC_PUBLIC | ACC_FINAL | ACC_SUPER |
ACC_INTERFACE | ACC_ABSTRACT |
ACC_SYNTHETIC | ACC_ANNOTATION |
ACC_ENUM | ACC_MODULE,
List.of(Map.entry(RELEASE_8, // no module
ACC_PUBLIC | ACC_FINAL | ACC_SUPER |
ACC_INTERFACE | ACC_ABSTRACT |
ACC_SYNTHETIC | ACC_ANNOTATION | ACC_ENUM),
Map.entry(RELEASE_4, // no synthetic, annotation, enum
ACC_PUBLIC | ACC_FINAL | ACC_SUPER |
ACC_INTERFACE | ACC_ABSTRACT))),
/**
* Field location.
*
* @see Field#accessFlags()
* @see FieldModel#flags()
* @see Modifier#fieldModifiers()
* @jvms 4.5 Fields
*/
FIELD(ACC_PUBLIC | ACC_PRIVATE | ACC_PROTECTED |
ACC_STATIC | ACC_FINAL | ACC_VOLATILE |
ACC_TRANSIENT | ACC_SYNTHETIC | ACC_ENUM,
List.of(Map.entry(RELEASE_4, // no synthetic, enum
ACC_PUBLIC | ACC_PRIVATE | ACC_PROTECTED |
ACC_STATIC | ACC_FINAL | ACC_VOLATILE |
ACC_TRANSIENT))),
/**
* Method location.
*
* @see Executable#accessFlags()
* @see MethodModel#flags()
* @see Modifier#methodModifiers()
* @see Modifier#constructorModifiers()
* @jvms 4.6 Methods
*/
METHOD(ACC_PUBLIC | ACC_PRIVATE | ACC_PROTECTED |
ACC_STATIC | ACC_FINAL | ACC_SYNCHRONIZED |
ACC_BRIDGE | ACC_VARARGS | ACC_NATIVE |
ACC_ABSTRACT | ACC_SYNTHETIC,
List.of(Map.entry(RELEASE_16, // had strict
ACC_PUBLIC | ACC_PRIVATE | ACC_PROTECTED |
ACC_STATIC | ACC_FINAL | ACC_SYNCHRONIZED |
ACC_BRIDGE | ACC_VARARGS | ACC_NATIVE |
ACC_ABSTRACT | ACC_STRICT | ACC_SYNTHETIC),
Map.entry(RELEASE_4, // no bridge, varargs, synthetic
ACC_PUBLIC | ACC_PRIVATE | ACC_PROTECTED |
ACC_STATIC | ACC_FINAL | ACC_SYNCHRONIZED |
ACC_NATIVE | ACC_ABSTRACT | ACC_STRICT),
Map.entry(RELEASE_1, // no strict
ACC_PUBLIC | ACC_PRIVATE | ACC_PROTECTED |
ACC_STATIC | ACC_FINAL | ACC_SYNCHRONIZED |
ACC_NATIVE | ACC_ABSTRACT))),
/**
* Inner class location.
*
* @see Class#accessFlags()
* @see InnerClassInfo#flags()
* @see Modifier#classModifiers()
* @see Modifier#interfaceModifiers()
* @jvms 4.7.6 The {@code InnerClasses} Attribute
*/
INNER_CLASS(ACC_PUBLIC | ACC_PRIVATE | ACC_PROTECTED |
ACC_STATIC | ACC_FINAL | ACC_INTERFACE | ACC_ABSTRACT |
ACC_SYNTHETIC | ACC_ANNOTATION | ACC_ENUM,
List.of(Map.entry(RELEASE_4, // no synthetic, annotation, enum
ACC_PUBLIC | ACC_PRIVATE | ACC_PROTECTED |
ACC_STATIC | ACC_FINAL | ACC_INTERFACE |
ACC_ABSTRACT),
Map.entry(RELEASE_0, 0))), // did not exist
/**
* Method parameter location.
*
* @see Parameter#accessFlags()
* @see MethodParameterInfo#flags()
* @see Modifier#parameterModifiers()
* @jvms 4.7.24 The {@code MethodParameters} Attribute
*/
METHOD_PARAMETER(ACC_FINAL | ACC_SYNTHETIC | ACC_MANDATED,
List.of(Map.entry(RELEASE_7, 0))), // did not exist
/**
* Module location.
*
* @see ModuleDescriptor#accessFlags()
* @see ModuleAttribute#moduleFlags()
* @jvms 4.7.25 The {@code Module} Attribute
*/
MODULE(ACC_OPEN | ACC_SYNTHETIC | ACC_MANDATED,
List.of(Map.entry(RELEASE_8, 0))), // did not exist
/**
* Module requires location.
*
* @see ModuleDescriptor.Requires#accessFlags()
* @see ModuleRequireInfo#requiresFlags()
* @jvms 4.7.25 The {@code Module} Attribute
*/
MODULE_REQUIRES(ACC_TRANSITIVE | ACC_STATIC_PHASE | ACC_SYNTHETIC | ACC_MANDATED,
List.of(Map.entry(RELEASE_8, 0))), // did not exist
/**
* Module exports location.
*
* @see ModuleDescriptor.Exports#accessFlags()
* @see ModuleExportInfo#exportsFlags()
* @jvms 4.7.25 The {@code Module} Attribute
*/
MODULE_EXPORTS(ACC_SYNTHETIC | ACC_MANDATED,
List.of(Map.entry(RELEASE_8, 0))), // did not exist
/**
* Module opens location.
*
* @see ModuleDescriptor.Opens#accessFlags()
* @see ModuleOpenInfo#opensFlags()
* @jvms 4.7.25 The {@code Module} Attribute
*/
MODULE_OPENS(ACC_SYNTHETIC | ACC_MANDATED,
List.of(Map.entry(RELEASE_8, 0))), // did not exist
;
// 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_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_5 =
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 5.0
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 final int flagsMask;
private final List<Map.Entry<ClassFileFormatVersion, Integer>> historicalFlagsMasks;
Location(int flagsMask,
List<Map.Entry<ClassFileFormatVersion, Integer>> historicalFlagsMasks) {
this.flagsMask = flagsMask;
this.historicalFlagsMasks = ensureHistoryOrdered(historicalFlagsMasks);
}
// Ensures the historical versions are from newest to oldest and do not include the latest
// These 2 utilities reside in Location because Location must be initialized before AccessFlag
private static <T> List<Map.Entry<ClassFileFormatVersion, T>> ensureHistoryOrdered(
List<Map.Entry<ClassFileFormatVersion, T>> history) {
ClassFileFormatVersion lastVersion = ClassFileFormatVersion.latest();
for (var e : history) {
var historyVersion = e.getKey();
if (lastVersion.compareTo(historyVersion) <= 0) {
throw new IllegalArgumentException("Versions out of order");
}
lastVersion = historyVersion;
}
return history;
}
private static <T> T findInHistory(T candidate, List<Map.Entry<ClassFileFormatVersion, T>> history,
ClassFileFormatVersion cffv) {
Objects.requireNonNull(cffv);
for (var e : history) {
if (e.getKey().compareTo(cffv) < 0) {
// last version found was valid
return candidate;
}
candidate = e.getValue();
}
return candidate;
}
/**
* {@return the union of masks of all access flags defined for
* this location in the current class file format version}
* <p>
* This method returns {@code 0} if this location does not exist in
* the current class file format version.
*
* @since 25
*/
public int flagsMask() {
return flagsMask;
}
/**
* {@return the union of masks of all access flags defined for
* this location in the given class file format version}
* <p>
* This method returns {@code 0} if this location does not exist in
* the given {@code cffv}.
*
* @param cffv the class file format version
* @throws NullPointerException if {@code cffv} is {@code null}
* @since 25
*/
public int flagsMask(ClassFileFormatVersion cffv) {
return findInHistory(flagsMask, historicalFlagsMasks, cffv);
}
/**
* {@return the set of access flags defined for this location in the
* current class file format version} The set is immutable.
* <p>
* This method returns an empty set if this location does not exist
* in the current class file format version.
*
* @since 25
*/
public Set<AccessFlag> flags() {
return new AccessFlagSet(findDefinition(this), flagsMask());
}
/**
* {@return the set of access flags defined for this location in the
* given class file format version} The set is immutable.
* <p>
* This method returns an empty set if this location does not exist
* in the given {@code cffv}.
*
* @param cffv the class file format version
* @throws NullPointerException if {@code cffv} is {@code null}
* @since 25
*/
public Set<AccessFlag> flags(ClassFileFormatVersion cffv) {
// implicit null check cffv
return new AccessFlagSet(findDefinition(this), flagsMask(cffv));
}
}
private static AccessFlag[] createDefinition(AccessFlag... known) {
var ret = new AccessFlag[Character.SIZE];
for (var flag : known) {
var mask = flag.mask;
int pos = Integer.numberOfTrailingZeros(mask);
assert ret[pos] == null : ret[pos] + " " + flag;
ret[pos] = flag;
}
return ret;
}
// Will take extra args in the future for valhalla switch
private static AccessFlag[] findDefinition(Location location) {
return switch (location) {
case CLASS -> CLASS_FLAGS;
case FIELD -> FIELD_FLAGS;
case METHOD -> METHOD_FLAGS;
case INNER_CLASS -> INNER_CLASS_FLAGS;
case METHOD_PARAMETER -> METHOD_PARAMETER_FLAGS;
case MODULE -> MODULE_FLAGS;
case MODULE_REQUIRES -> MODULE_REQUIRES_FLAGS;
case MODULE_EXPORTS -> MODULE_EXPORTS_FLAGS;
case MODULE_OPENS -> MODULE_OPENS_FLAGS;
};
}
private static final @Stable AccessFlag[] // Can use stable array and lazy init in the future
CLASS_FLAGS = createDefinition(PUBLIC, FINAL, SUPER, INTERFACE, ABSTRACT, SYNTHETIC, ANNOTATION, ENUM, MODULE),
FIELD_FLAGS = createDefinition(PUBLIC, PRIVATE, PROTECTED, STATIC, FINAL, VOLATILE, TRANSIENT, SYNTHETIC, ENUM),
METHOD_FLAGS = createDefinition(PUBLIC, PRIVATE, PROTECTED, STATIC, FINAL, SYNCHRONIZED, BRIDGE, VARARGS, NATIVE, ABSTRACT, STRICT, SYNTHETIC),
INNER_CLASS_FLAGS = createDefinition(PUBLIC, PRIVATE, PROTECTED, STATIC, FINAL, INTERFACE, ABSTRACT, SYNTHETIC, ANNOTATION, ENUM),
METHOD_PARAMETER_FLAGS = createDefinition(FINAL, SYNTHETIC, MANDATED),
MODULE_FLAGS = createDefinition(OPEN, SYNTHETIC, MANDATED),
MODULE_REQUIRES_FLAGS = createDefinition(TRANSITIVE, STATIC_PHASE, SYNTHETIC, MANDATED),
MODULE_EXPORTS_FLAGS = createDefinition(SYNTHETIC, MANDATED),
MODULE_OPENS_FLAGS = createDefinition(SYNTHETIC, MANDATED);
private static int undefinedMask(AccessFlag[] definition, int mask) {
assert definition.length == Character.SIZE;
int definedMask = 0;
for (int i = 0; i < Character.SIZE; i++) {
if (definition[i] != null) {
definedMask |= 1 << i;
}
}
return mask & ~definedMask;
}
private static final class AccessFlagSet extends AbstractSet<AccessFlag> {
private final @Stable AccessFlag[] definition;
private final int mask;
// all mutating methods throw UnsupportedOperationException
@Override public boolean add(AccessFlag e) { throw uoe(); }
@Override public boolean addAll(Collection<? extends AccessFlag> c) { throw uoe(); }
@Override public void clear() { throw uoe(); }
@Override public boolean remove(Object o) { throw uoe(); }
@Override public boolean removeAll(Collection<?> c) { throw uoe(); }
@Override public boolean removeIf(Predicate<? super AccessFlag> filter) { throw uoe(); }
@Override public boolean retainAll(Collection<?> c) { throw uoe(); }
private static UnsupportedOperationException uoe() { return new UnsupportedOperationException(); }
private AccessFlagSet(AccessFlag[] definition, int mask) {
assert undefinedMask(definition, mask) == 0 : mask;
this.definition = definition;
this.mask = mask;
}
@Override
public Iterator<AccessFlag> iterator() {
return new AccessFlagIterator(definition, mask);
}
@Override
public void forEach(Consumer<? super AccessFlag> action) {
Objects.requireNonNull(action); // in case of empty
for (int i = 0; i < Character.SIZE; i++) {
if ((mask & (1 << i)) != 0) {
action.accept(definition[i]);
}
}
}
private static final class AccessFlagIterator implements Iterator<AccessFlag> {
private final @Stable AccessFlag[] definition;
private int remainingMask;
private AccessFlagIterator(AccessFlag[] definition, int remainingMask) {
this.definition = definition;
this.remainingMask = remainingMask;
}
@Override
public boolean hasNext() {
return remainingMask != 0;
}
@Override
public AccessFlag next() {
int flagBit = Integer.lowestOneBit(remainingMask);
if (flagBit == 0) {
throw new NoSuchElementException();
}
remainingMask &= ~flagBit;
return definition[Integer.numberOfTrailingZeros(flagBit)];
}
}
@Override
public int size() {
return Integer.bitCount(mask);
}
@Override
public boolean contains(Object o) {
if (Objects.requireNonNull(o) instanceof AccessFlag flag) {
int bit = flag.mask;
return (bit & mask) != 0 && definition[Integer.numberOfTrailingZeros(bit)] == flag;
}
return false;
}
@Override
public boolean isEmpty() {
return mask == 0;
}
}
}