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	/*
	* Copyright (c) 2008, 2020, 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.invoke;

	import sun.invoke.util.BytecodeDescriptor;
	import sun.invoke.util.VerifyAccess;

	import java.lang.reflect.Constructor;
	import java.lang.reflect.Field;
	import java.lang.reflect.Member;
	import java.lang.reflect.Method;
	import java.lang.reflect.Modifier;
	import java.util.ArrayList;
	import java.util.Collections;
	import java.util.Iterator;
	import java.util.List;
	import java.util.Objects;

	import static java.lang.invoke.MethodHandleNatives.Constants.*;
	import static java.lang.invoke.MethodHandleStatics.newIllegalArgumentException;
	import static java.lang.invoke.MethodHandleStatics.newInternalError;

	/**
	* A {@code MemberName} is a compact symbolic datum which fully characterizes
	* a method or field reference.
	* A member name refers to a field, method, constructor, or member type.
	* Every member name has a simple name (a string) and a type (either a Class or MethodType).
	* A member name may also have a non-null declaring class, or it may be simply
	* a naked name/type pair.
	* A member name may also have non-zero modifier flags.
	* Finally, a member name may be either resolved or unresolved.
	* If it is resolved, the existence of the named member has been determined by the JVM.
	* <p>
	* Whether resolved or not, a member name provides no access rights or
	* invocation capability to its possessor. It is merely a compact
	* representation of all symbolic information necessary to link to
	* and properly use the named member.
	* <p>
	* When resolved, a member name's internal implementation may include references to JVM metadata.
	* This representation is stateless and only descriptive.
	* It provides no private information and no capability to use the member.
	* <p>
	* By contrast, a {@linkplain java.lang.reflect.Method} contains fuller information
	* about the internals of a method (except its bytecodes) and also
	* allows invocation. A MemberName is much lighter than a Method,
	* since it contains about 7 fields to the 16 of Method (plus its sub-arrays),
	* and those seven fields omit much of the information in Method.
	* @author jrose
	*/
	/non-public/
	final class ResolvedMethodName {
	//@Injected JVM_Method* vmtarget;
	//@Injected Class<?> vmholder;
	};

	/non-public/
	final class MemberName implements Member, Cloneable {
	private Class<?> clazz; // class in which the member is defined
	private String name; // may be null if not yet materialized
	private Object type; // may be null if not yet materialized
	private int flags; // modifier bits; see reflect.Modifier
	private ResolvedMethodName method; // cached resolved method information
	//@Injected intptr_t vmindex; // vtable index or offset of resolved member
	Object resolution; // if null, this guy is resolved

	/** Return the declaring class of this member.
	* In the case of a bare name and type, the declaring class will be null.
	*/
	public Class<?> getDeclaringClass() {
	return clazz;
	}

	/** Utility method producing the class loader of the declaring class. */
	public ClassLoader getClassLoader() {
	return clazz.getClassLoader();
	}

	/** Return the simple name of this member.
	* For a type, it is the same as {@link Class#getSimpleName}.
	* For a method or field, it is the simple name of the member.
	* For a constructor, it is always {@code "<init>"}.
	*/
	public String getName() {
	if (name == null) {
	expandFromVM();
	if (name == null) {
	return null;
	}
	}
	return name;
	}

	public MethodType getMethodOrFieldType() {
	if (isInvocable())
	return getMethodType();
	if (isGetter())
	return MethodType.methodType(getFieldType());
	if (isSetter())
	return MethodType.methodType(void.class, getFieldType());
	throw new InternalError("not a method or field: "+this);
	}

	/** Return the declared type of this member, which
	* must be a method or constructor.
	*/
	public MethodType getMethodType() {
	if (type == null) {
	expandFromVM();
	if (type == null) {
	return null;
	}
	}
	if (!isInvocable()) {
	throw newIllegalArgumentException("not invocable, no method type");
	}

	{
	// Get a snapshot of type which doesn't get changed by racing threads.
	final Object type = this.type;
	if (type instanceof MethodType) {
	return (MethodType) type;
	}
	}

	// type is not a MethodType yet. Convert it thread-safely.
	synchronized (this) {
	if (type instanceof String sig) {
	MethodType res = MethodType.fromDescriptor(sig, getClassLoader());
	type = res;
	} else if (type instanceof Object[] typeInfo) {
	Class<?>[] ptypes = (Class<?>[]) typeInfo[1];
	Class<?> rtype = (Class<?>) typeInfo[0];
	MethodType res = MethodType.makeImpl(rtype, ptypes, true);
	type = res;
	}
	// Make sure type is a MethodType for racing threads.
	assert type instanceof MethodType : "bad method type " + type;
	}
	return (MethodType) type;
	}

	/** Return the descriptor of this member, which
	* must be a method or constructor.
	*/
	String getMethodDescriptor() {
	if (type == null) {
	expandFromVM();
	if (type == null) {
	return null;
	}
	}
	if (!isInvocable()) {
	throw newIllegalArgumentException("not invocable, no method type");
	}

	// Get a snapshot of type which doesn't get changed by racing threads.
	final Object type = this.type;
	if (type instanceof String) {
	return (String) type;
	} else {
	return getMethodType().toMethodDescriptorString();
	}
	}

	/** Return the actual type under which this method or constructor must be invoked.
	* For non-static methods or constructors, this is the type with a leading parameter,
	* a reference to declaring class. For static methods, it is the same as the declared type.
	*/
	public MethodType getInvocationType() {
	MethodType itype = getMethodOrFieldType();
	if (isConstructor() && getReferenceKind() == REF_newInvokeSpecial)
	return itype.changeReturnType(clazz);
	if (!isStatic())
	return itype.insertParameterTypes(0, clazz);
	return itype;
	}

	/** Utility method producing the parameter types of the method type. */
	public Class<?>[] getParameterTypes() {
	return getMethodType().parameterArray();
	}

	/** Utility method producing the return type of the method type. */
	public Class<?> getReturnType() {
	return getMethodType().returnType();
	}

	/** Return the declared type of this member, which
	* must be a field or type.
	* If it is a type member, that type itself is returned.
	*/
	public Class<?> getFieldType() {
	if (type == null) {
	expandFromVM();
	if (type == null) {
	return null;
	}
	}
	if (isInvocable()) {
	throw newIllegalArgumentException("not a field or nested class, no simple type");
	}

	{
	// Get a snapshot of type which doesn't get changed by racing threads.
	final Object type = this.type;
	if (type instanceof Class<?>) {
	return (Class<?>) type;
	}
	}

	// type is not a Class yet. Convert it thread-safely.
	synchronized (this) {
	if (type instanceof String sig) {
	MethodType mtype = MethodType.fromDescriptor("()"+sig, getClassLoader());
	Class<?> res = mtype.returnType();
	type = res;
	}
	// Make sure type is a Class for racing threads.
	assert type instanceof Class<?> : "bad field type " + type;
	}
	return (Class<?>) type;
	}

	/** Utility method to produce either the method type or field type of this member. */
	public Object getType() {
	return (isInvocable() ? getMethodType() : getFieldType());
	}

	/** Utility method to produce the signature of this member,
	* used within the class file format to describe its type.
	*/
	public String getSignature() {
	if (type == null) {
	expandFromVM();
	if (type == null) {
	return null;
	}
	}
	if (isInvocable())
	return BytecodeDescriptor.unparse(getMethodType());
	else
	return BytecodeDescriptor.unparse(getFieldType());
	}

	/** Return the modifier flags of this member.
	* @see java.lang.reflect.Modifier
	*/
	public int getModifiers() {
	return (flags & RECOGNIZED_MODIFIERS);
	}

	/** Return the reference kind of this member, or zero if none.
	*/
	public byte getReferenceKind() {
	return (byte) ((flags >>> MN_REFERENCE_KIND_SHIFT) & MN_REFERENCE_KIND_MASK);
	}
	private boolean referenceKindIsConsistent() {
	byte refKind = getReferenceKind();
	if (refKind == REF_NONE) return isType();
	if (isField()) {
	assert(staticIsConsistent());
	assert(MethodHandleNatives.refKindIsField(refKind));
	} else if (isConstructor()) {
	assert(refKind == REF_newInvokeSpecial \|\| refKind == REF_invokeSpecial);
	} else if (isMethod()) {
	assert(staticIsConsistent());
	assert(MethodHandleNatives.refKindIsMethod(refKind));
	if (clazz.isInterface())
	assert(refKind == REF_invokeInterface \|\|
	refKind == REF_invokeStatic \|\|
	refKind == REF_invokeSpecial \|\|
	refKind == REF_invokeVirtual && isObjectPublicMethod());
	} else {
	assert(false);
	}
	return true;
	}
	private boolean isObjectPublicMethod() {
	if (clazz == Object.class) return true;
	MethodType mtype = getMethodType();
	if (name.equals("toString") && mtype.returnType() == String.class && mtype.parameterCount() == 0)
	return true;
	if (name.equals("hashCode") && mtype.returnType() == int.class && mtype.parameterCount() == 0)
	return true;
	if (name.equals("equals") && mtype.returnType() == boolean.class && mtype.parameterCount() == 1 && mtype.parameterType(0) == Object.class)
	return true;
	return false;
	}

	/non-public/
	boolean referenceKindIsConsistentWith(int originalRefKind) {
	int refKind = getReferenceKind();
	if (refKind == originalRefKind) return true;
	if (getClass().desiredAssertionStatus()) {
	switch (originalRefKind) {
	case REF_invokeInterface -> {
	// Looking up an interface method, can get (e.g.) Object.hashCode
	assert (refKind == REF_invokeVirtual \|\| refKind == REF_invokeSpecial) : this;
	}
	case REF_invokeVirtual, REF_newInvokeSpecial -> {
	// Looked up a virtual, can get (e.g.) final String.hashCode.
	assert (refKind == REF_invokeSpecial) : this;
	}
	default -> {
	assert (false) : this + " != " + MethodHandleNatives.refKindName((byte) originalRefKind);
	}
	}
	}
	return true;
	}
	private boolean staticIsConsistent() {
	byte refKind = getReferenceKind();
	return MethodHandleNatives.refKindIsStatic(refKind) == isStatic() \|\| getModifiers() == 0;
	}
	private boolean vminfoIsConsistent() {
	byte refKind = getReferenceKind();
	assert(isResolved()); // else don't call
	Object vminfo = MethodHandleNatives.getMemberVMInfo(this);
	assert(vminfo instanceof Object[]);
	long vmindex = (Long) ((Object[])vminfo)[0];
	Object vmtarget = ((Object[])vminfo)[1];
	if (MethodHandleNatives.refKindIsField(refKind)) {
	assert(vmindex >= 0) : vmindex + ":" + this;
	assert(vmtarget instanceof Class);
	} else {
	if (MethodHandleNatives.refKindDoesDispatch(refKind))
	assert(vmindex >= 0) : vmindex + ":" + this;
	else
	assert(vmindex < 0) : vmindex;
	assert(vmtarget instanceof MemberName) : vmtarget + " in " + this;
	}
	return true;
	}

	private MemberName changeReferenceKind(byte refKind, byte oldKind) {
	assert(getReferenceKind() == oldKind);
	assert(MethodHandleNatives.refKindIsValid(refKind));
	flags += (((int)refKind - oldKind) << MN_REFERENCE_KIND_SHIFT);
	return this;
	}

	private boolean testFlags(int mask, int value) {
	return (flags & mask) == value;
	}
	private boolean testAllFlags(int mask) {
	return testFlags(mask, mask);
	}
	private boolean testAnyFlags(int mask) {
	return !testFlags(mask, 0);
	}

	/** Utility method to query if this member is a method handle invocation (invoke or invokeExact).
	*/
	public boolean isMethodHandleInvoke() {
	final int bits = MH_INVOKE_MODS &~ Modifier.PUBLIC;
	final int negs = Modifier.STATIC;
	if (testFlags(bits \| negs, bits) &&
	clazz == MethodHandle.class) {
	return isMethodHandleInvokeName(name);
	}
	return false;
	}
	public static boolean isMethodHandleInvokeName(String name) {
	switch (name) {
	case "invoke":
	case "invokeExact":
	return true;
	default:
	return false;
	}
	}
	public boolean isVarHandleMethodInvoke() {
	final int bits = MH_INVOKE_MODS &~ Modifier.PUBLIC;
	final int negs = Modifier.STATIC;
	if (testFlags(bits \| negs, bits) &&
	clazz == VarHandle.class) {
	return isVarHandleMethodInvokeName(name);
	}
	return false;
	}
	public static boolean isVarHandleMethodInvokeName(String name) {
	try {
	VarHandle.AccessMode.valueFromMethodName(name);
	return true;
	} catch (IllegalArgumentException e) {
	return false;
	}
	}
	private static final int MH_INVOKE_MODS = Modifier.NATIVE \| Modifier.FINAL \| Modifier.PUBLIC;

	/** Utility method to query the modifier flags of this member. */
	public boolean isStatic() {
	return Modifier.isStatic(flags);
	}
	/** Utility method to query the modifier flags of this member. */
	public boolean isPublic() {
	return Modifier.isPublic(flags);
	}
	/** Utility method to query the modifier flags of this member. */
	public boolean isPrivate() {
	return Modifier.isPrivate(flags);
	}
	/** Utility method to query the modifier flags of this member. */
	public boolean isProtected() {
	return Modifier.isProtected(flags);
	}
	/** Utility method to query the modifier flags of this member. */
	public boolean isFinal() {
	return Modifier.isFinal(flags);
	}
	/** Utility method to query whether this member or its defining class is final. */
	public boolean canBeStaticallyBound() {
	return Modifier.isFinal(flags \| clazz.getModifiers());
	}
	/** Utility method to query the modifier flags of this member. */
	public boolean isVolatile() {
	return Modifier.isVolatile(flags);
	}
	/** Utility method to query the modifier flags of this member. */
	public boolean isAbstract() {
	return Modifier.isAbstract(flags);
	}
	/** Utility method to query the modifier flags of this member. */
	public boolean isNative() {
	return Modifier.isNative(flags);
	}
	// let the rest (native, volatile, transient, etc.) be tested via Modifier.isFoo

	// unofficial modifier flags, used by HotSpot:
	static final int BRIDGE = 0x00000040;
	static final int VARARGS = 0x00000080;
	static final int SYNTHETIC = 0x00001000;
	static final int ANNOTATION= 0x00002000;
	static final int ENUM = 0x00004000;
	/** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
	public boolean isBridge() {
	return testAllFlags(IS_METHOD \| BRIDGE);
	}
	/** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
	public boolean isVarargs() {
	return testAllFlags(VARARGS) && isInvocable();
	}
	/** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
	public boolean isSynthetic() {
	return testAllFlags(SYNTHETIC);
	}

	static final String CONSTRUCTOR_NAME = "<init>"; // the ever-popular

	// modifiers exported by the JVM:
	static final int RECOGNIZED_MODIFIERS = 0xFFFF;

	// private flags, not part of RECOGNIZED_MODIFIERS:
	static final int
	IS_METHOD = MN_IS_METHOD, // method (not constructor)
	IS_CONSTRUCTOR = MN_IS_CONSTRUCTOR, // constructor
	IS_FIELD = MN_IS_FIELD, // field
	IS_TYPE = MN_IS_TYPE, // nested type
	CALLER_SENSITIVE = MN_CALLER_SENSITIVE, // @CallerSensitive annotation detected
	TRUSTED_FINAL = MN_TRUSTED_FINAL; // trusted final field

	static final int ALL_ACCESS = Modifier.PUBLIC \| Modifier.PRIVATE \| Modifier.PROTECTED;
	static final int ALL_KINDS = IS_METHOD \| IS_CONSTRUCTOR \| IS_FIELD \| IS_TYPE;
	static final int IS_INVOCABLE = IS_METHOD \| IS_CONSTRUCTOR;
	static final int IS_FIELD_OR_METHOD = IS_METHOD \| IS_FIELD;
	static final int SEARCH_ALL_SUPERS = MN_SEARCH_SUPERCLASSES \| MN_SEARCH_INTERFACES;

	/** Utility method to query whether this member is a method or constructor. */
	public boolean isInvocable() {
	return testAnyFlags(IS_INVOCABLE);
	}
	/** Utility method to query whether this member is a method, constructor, or field. */
	public boolean isFieldOrMethod() {
	return testAnyFlags(IS_FIELD_OR_METHOD);
	}
	/** Query whether this member is a method. */
	public boolean isMethod() {
	return testAllFlags(IS_METHOD);
	}
	/** Query whether this member is a constructor. */
	public boolean isConstructor() {
	return testAllFlags(IS_CONSTRUCTOR);
	}
	/** Query whether this member is a field. */
	public boolean isField() {
	return testAllFlags(IS_FIELD);
	}
	/** Query whether this member is a type. */
	public boolean isType() {
	return testAllFlags(IS_TYPE);
	}
	/** Utility method to query whether this member is neither public, private, nor protected. */
	public boolean isPackage() {
	return !testAnyFlags(ALL_ACCESS);
	}
	/** Query whether this member has a CallerSensitive annotation. */
	public boolean isCallerSensitive() {
	return testAllFlags(CALLER_SENSITIVE);
	}
	/** Query whether this member is a trusted final field. */
	public boolean isTrustedFinalField() { return testAllFlags(TRUSTED_FINAL\|IS_FIELD); }

	/** Utility method to query whether this member is accessible from a given lookup class. */
	public boolean isAccessibleFrom(Class<?> lookupClass) {
	int mode = (ALL_ACCESS\|MethodHandles.Lookup.PACKAGE\|MethodHandles.Lookup.MODULE);
	return VerifyAccess.isMemberAccessible(this.getDeclaringClass(), this.getDeclaringClass(), flags,
	lookupClass, null, mode);
	}

	/**
	* Check if MemberName is a call to a method named {@code name} in class {@code declaredClass}.
	*/
	public boolean refersTo(Class<?> declc, String n) {
	return clazz == declc && getName().equals(n);
	}

	/** Initialize a query. It is not resolved. */
	private void init(Class<?> defClass, String name, Object type, int flags) {
	// defining class is allowed to be null (for a naked name/type pair)
	//name.toString(); // null check
	//type.equals(type); // null check
	// fill in fields:
	this.clazz = defClass;
	this.name = name;
	this.type = type;
	this.flags = flags;
	assert(testAnyFlags(ALL_KINDS));
	assert(this.resolution == null); // nobody should have touched this yet
	//assert(referenceKindIsConsistent()); // do this after resolution
	}

	/**
	* Calls down to the VM to fill in the fields. This method is
	* synchronized to avoid racing calls.
	*/
	private void expandFromVM() {
	if (type != null) {
	return;
	}
	if (!isResolved()) {
	return;
	}
	MethodHandleNatives.expand(this);
	}

	// Capturing information from the Core Reflection API:
	private static int flagsMods(int flags, int mods, byte refKind) {
	assert((flags & RECOGNIZED_MODIFIERS) == 0);
	assert((mods & ~RECOGNIZED_MODIFIERS) == 0);
	assert((refKind & ~MN_REFERENCE_KIND_MASK) == 0);
	return flags \| mods \| (refKind << MN_REFERENCE_KIND_SHIFT);
	}
	/** Create a name for the given reflected method. The resulting name will be in a resolved state. */
	public MemberName(Method m) {
	this(m, false);
	}
	@SuppressWarnings("LeakingThisInConstructor")
	public MemberName(Method m, boolean wantSpecial) {
	Objects.requireNonNull(m);
	// fill in vmtarget, vmindex while we have m in hand:
	MethodHandleNatives.init(this, m);
	if (clazz == null) { // MHN.init failed
	if (m.getDeclaringClass() == MethodHandle.class &&
	isMethodHandleInvokeName(m.getName())) {
	// The JVM did not reify this signature-polymorphic instance.
	// Need a special case here.
	// See comments on MethodHandleNatives.linkMethod.
	MethodType type = MethodType.methodType(m.getReturnType(), m.getParameterTypes());
	int flags = flagsMods(IS_METHOD, m.getModifiers(), REF_invokeVirtual);
	init(MethodHandle.class, m.getName(), type, flags);
	if (isMethodHandleInvoke())
	return;
	}
	if (m.getDeclaringClass() == VarHandle.class &&
	isVarHandleMethodInvokeName(m.getName())) {
	// The JVM did not reify this signature-polymorphic instance.
	// Need a special case here.
	// See comments on MethodHandleNatives.linkMethod.
	MethodType type = MethodType.methodType(m.getReturnType(), m.getParameterTypes());
	int flags = flagsMods(IS_METHOD, m.getModifiers(), REF_invokeVirtual);
	init(VarHandle.class, m.getName(), type, flags);
	if (isVarHandleMethodInvoke())
	return;
	}
	throw new LinkageError(m.toString());
	}
	assert(isResolved() && this.clazz != null);
	this.name = m.getName();
	if (this.type == null)
	this.type = new Object[] { m.getReturnType(), m.getParameterTypes() };
	if (wantSpecial) {
	if (isAbstract())
	throw new AbstractMethodError(this.toString());
	if (getReferenceKind() == REF_invokeVirtual)
	changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual);
	else if (getReferenceKind() == REF_invokeInterface)
	// invokeSpecial on a default method
	changeReferenceKind(REF_invokeSpecial, REF_invokeInterface);
	}
	}
	public MemberName asSpecial() {
	switch (getReferenceKind()) {
	case REF_invokeSpecial: return this;
	case REF_invokeVirtual: return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual);
	case REF_invokeInterface: return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeInterface);
	case REF_newInvokeSpecial: return clone().changeReferenceKind(REF_invokeSpecial, REF_newInvokeSpecial);
	}
	throw new IllegalArgumentException(this.toString());
	}
	/** If this MN is not REF_newInvokeSpecial, return a clone with that ref. kind.
	* In that case it must already be REF_invokeSpecial.
	*/
	public MemberName asConstructor() {
	switch (getReferenceKind()) {
	case REF_invokeSpecial: return clone().changeReferenceKind(REF_newInvokeSpecial, REF_invokeSpecial);
	case REF_newInvokeSpecial: return this;
	}
	throw new IllegalArgumentException(this.toString());
	}
	/** If this MN is a REF_invokeSpecial, return a clone with the "normal" kind
	* REF_invokeVirtual; also switch either to REF_invokeInterface if clazz.isInterface.
	* The end result is to get a fully virtualized version of the MN.
	* (Note that resolving in the JVM will sometimes devirtualize, changing
	* REF_invokeVirtual of a final to REF_invokeSpecial, and REF_invokeInterface
	* in some corner cases to either of the previous two; this transform
	* undoes that change under the assumption that it occurred.)
	*/
	public MemberName asNormalOriginal() {
	byte normalVirtual = clazz.isInterface() ? REF_invokeInterface : REF_invokeVirtual;
	byte refKind = getReferenceKind();
	byte newRefKind = refKind;
	MemberName result = this;
	switch (refKind) {
	case REF_invokeInterface:
	case REF_invokeVirtual:
	case REF_invokeSpecial:
	newRefKind = normalVirtual;
	break;
	}
	if (newRefKind == refKind)
	return this;
	result = clone().changeReferenceKind(newRefKind, refKind);
	assert(this.referenceKindIsConsistentWith(result.getReferenceKind()));
	return result;
	}
	/** Create a name for the given reflected constructor. The resulting name will be in a resolved state. */
	@SuppressWarnings("LeakingThisInConstructor")
	public MemberName(Constructor<?> ctor) {
	Objects.requireNonNull(ctor);
	// fill in vmtarget, vmindex while we have ctor in hand:
	MethodHandleNatives.init(this, ctor);
	assert(isResolved() && this.clazz != null);
	this.name = CONSTRUCTOR_NAME;
	if (this.type == null)
	this.type = new Object[] { void.class, ctor.getParameterTypes() };
	}
	/** Create a name for the given reflected field. The resulting name will be in a resolved state.
	*/
	public MemberName(Field fld) {
	this(fld, false);
	}
	@SuppressWarnings("LeakingThisInConstructor")
	public MemberName(Field fld, boolean makeSetter) {
	Objects.requireNonNull(fld);
	// fill in vmtarget, vmindex while we have fld in hand:
	MethodHandleNatives.init(this, fld);
	assert(isResolved() && this.clazz != null);
	this.name = fld.getName();
	this.type = fld.getType();
	assert((REF_putStatic - REF_getStatic) == (REF_putField - REF_getField));
	byte refKind = this.getReferenceKind();
	assert(refKind == (isStatic() ? REF_getStatic : REF_getField));
	if (makeSetter) {
	changeReferenceKind((byte)(refKind + (REF_putStatic - REF_getStatic)), refKind);
	}
	}
	public boolean isGetter() {
	return MethodHandleNatives.refKindIsGetter(getReferenceKind());
	}
	public boolean isSetter() {
	return MethodHandleNatives.refKindIsSetter(getReferenceKind());
	}
	public MemberName asSetter() {
	byte refKind = getReferenceKind();
	assert(MethodHandleNatives.refKindIsGetter(refKind));
	assert((REF_putStatic - REF_getStatic) == (REF_putField - REF_getField));
	byte setterRefKind = (byte)(refKind + (REF_putField - REF_getField));
	return clone().changeReferenceKind(setterRefKind, refKind);
	}
	/** Create a name for the given class. The resulting name will be in a resolved state. */
	public MemberName(Class<?> type) {
	init(type.getDeclaringClass(), type.getSimpleName(), type,
	flagsMods(IS_TYPE, type.getModifiers(), REF_NONE));
	initResolved(true);
	}

	/**
	* Create a name for a signature-polymorphic invoker.
	* This is a placeholder for a signature-polymorphic instance
	* (of MH.invokeExact, etc.) that the JVM does not reify.
	* See comments on {@link MethodHandleNatives#linkMethod}.
	*/
	static MemberName makeMethodHandleInvoke(String name, MethodType type) {
	return makeMethodHandleInvoke(name, type, MH_INVOKE_MODS \| SYNTHETIC);
	}
	static MemberName makeMethodHandleInvoke(String name, MethodType type, int mods) {
	MemberName mem = new MemberName(MethodHandle.class, name, type, REF_invokeVirtual);
	mem.flags \|= mods; // it's not resolved, but add these modifiers anyway
	assert(mem.isMethodHandleInvoke()) : mem;
	return mem;
	}

	static MemberName makeVarHandleMethodInvoke(String name, MethodType type) {
	return makeVarHandleMethodInvoke(name, type, MH_INVOKE_MODS \| SYNTHETIC);
	}
	static MemberName makeVarHandleMethodInvoke(String name, MethodType type, int mods) {
	MemberName mem = new MemberName(VarHandle.class, name, type, REF_invokeVirtual);
	mem.flags \|= mods; // it's not resolved, but add these modifiers anyway
	assert(mem.isVarHandleMethodInvoke()) : mem;
	return mem;
	}

	// bare-bones constructor; the JVM will fill it in
	MemberName() { }

	// locally useful cloner
	@Override protected MemberName clone() {
	try {
	return (MemberName) super.clone();
	} catch (CloneNotSupportedException ex) {
	throw newInternalError(ex);
	}
	}

	/** Get the definition of this member name.
	* This may be in a super-class of the declaring class of this member.
	*/
	public MemberName getDefinition() {
	if (!isResolved()) throw new IllegalStateException("must be resolved: "+this);
	if (isType()) return this;
	MemberName res = this.clone();
	res.clazz = null;
	res.type = null;
	res.name = null;
	res.resolution = res;
	res.expandFromVM();
	assert(res.getName().equals(this.getName()));
	return res;
	}

	@Override
	@SuppressWarnings({"deprecation", "removal"})
	public int hashCode() {
	// Avoid autoboxing getReferenceKind(), since this is used early and will force
	// early initialization of Byte$ByteCache
	return Objects.hash(clazz, new Byte(getReferenceKind()), name, getType());
	}

	@Override
	public boolean equals(Object that) {
	return (that instanceof MemberName && this.equals((MemberName)that));
	}

	/** Decide if two member names have exactly the same symbolic content.
	* Does not take into account any actual class members, so even if
	* two member names resolve to the same actual member, they may
	* be distinct references.
	*/
	public boolean equals(MemberName that) {
	if (this == that) return true;
	if (that == null) return false;
	return this.clazz == that.clazz
	&& this.getReferenceKind() == that.getReferenceKind()
	&& Objects.equals(this.name, that.name)
	&& Objects.equals(this.getType(), that.getType());
	}

	// Construction from symbolic parts, for queries:
	/** Create a field or type name from the given components:
	* Declaring class, name, type, reference kind.
	* The declaring class may be supplied as null if this is to be a bare name and type.
	* The resulting name will in an unresolved state.
	*/
	public MemberName(Class<?> defClass, String name, Class<?> type, byte refKind) {
	init(defClass, name, type, flagsMods(IS_FIELD, 0, refKind));
	initResolved(false);
	}
	/** Create a method or constructor name from the given components:
	* Declaring class, name, type, reference kind.
	* It will be a constructor if and only if the name is {@code "<init>"}.
	* The declaring class may be supplied as null if this is to be a bare name and type.
	* The last argument is optional, a boolean which requests REF_invokeSpecial.
	* The resulting name will in an unresolved state.
	*/
	public MemberName(Class<?> defClass, String name, MethodType type, byte refKind) {
	int initFlags = (name != null && name.equals(CONSTRUCTOR_NAME) ? IS_CONSTRUCTOR : IS_METHOD);
	init(defClass, name, type, flagsMods(initFlags, 0, refKind));
	initResolved(false);
	}
	/** Create a method, constructor, or field name from the given components:
	* Reference kind, declaring class, name, type.
	*/
	public MemberName(byte refKind, Class<?> defClass, String name, Object type) {
	int kindFlags;
	if (MethodHandleNatives.refKindIsField(refKind)) {
	kindFlags = IS_FIELD;
	if (!(type instanceof Class))
	throw newIllegalArgumentException("not a field type");
	} else if (MethodHandleNatives.refKindIsMethod(refKind)) {
	kindFlags = IS_METHOD;
	if (!(type instanceof MethodType))
	throw newIllegalArgumentException("not a method type");
	} else if (refKind == REF_newInvokeSpecial) {
	kindFlags = IS_CONSTRUCTOR;
	if (!(type instanceof MethodType) \|\|
	!CONSTRUCTOR_NAME.equals(name))
	throw newIllegalArgumentException("not a constructor type or name");
	} else {
	throw newIllegalArgumentException("bad reference kind "+refKind);
	}
	init(defClass, name, type, flagsMods(kindFlags, 0, refKind));
	initResolved(false);
	}
	/** Query whether this member name is resolved to a non-static, non-final method.
	*/
	public boolean hasReceiverTypeDispatch() {
	return MethodHandleNatives.refKindDoesDispatch(getReferenceKind());
	}

	/** Query whether this member name is resolved.
	* A resolved member name is one for which the JVM has found
	* a method, constructor, field, or type binding corresponding exactly to the name.
	* (Document?)
	*/
	public boolean isResolved() {
	return resolution == null;
	}

	void initResolved(boolean isResolved) {
	assert(this.resolution == null); // not initialized yet!
	if (!isResolved)
	this.resolution = this;
	assert(isResolved() == isResolved);
	}

	void checkForTypeAlias(Class<?> refc) {
	if (isInvocable()) {
	MethodType type;
	if (this.type instanceof MethodType)
	type = (MethodType) this.type;
	else
	this.type = type = getMethodType();
	if (type.erase() == type) return;
	if (VerifyAccess.isTypeVisible(type, refc)) return;
	throw new LinkageError("bad method type alias: "+type+" not visible from "+refc);
	} else {
	Class<?> type;
	if (this.type instanceof Class<?>)
	type = (Class<?>) this.type;
	else
	this.type = type = getFieldType();
	if (VerifyAccess.isTypeVisible(type, refc)) return;
	throw new LinkageError("bad field type alias: "+type+" not visible from "+refc);
	}
	}


	/** Produce a string form of this member name.
	* For types, it is simply the type's own string (as reported by {@code toString}).
	* For fields, it is {@code "DeclaringClass.name/type"}.
	* For methods and constructors, it is {@code "DeclaringClass.name(ptype...)rtype"}.
	* If the declaring class is null, the prefix {@code "DeclaringClass."} is omitted.
	* If the member is unresolved, a prefix {@code "*."} is prepended.
	*/
	@SuppressWarnings("LocalVariableHidesMemberVariable")
	@Override
	public String toString() {
	if (isType())
	return type.toString(); // class java.lang.String
	// else it is a field, method, or constructor
	StringBuilder buf = new StringBuilder();
	if (getDeclaringClass() != null) {
	buf.append(getName(clazz));
	buf.append('.');
	}
	String name = this.name; // avoid expanding from VM
	buf.append(name == null ? "*" : name);
	Object type = this.type; // avoid expanding from VM
	if (!isInvocable()) {
	buf.append('/');
	buf.append(type == null ? "*" : getName(type));
	} else {
	buf.append(type == null ? "()" : getName(type));
	}
	byte refKind = getReferenceKind();
	if (refKind != REF_NONE) {
	buf.append('/');
	buf.append(MethodHandleNatives.refKindName(refKind));
	}
	//buf.append("#").append(System.identityHashCode(this));
	return buf.toString();
	}
	private static String getName(Object obj) {
	if (obj instanceof Class<?>)
	return ((Class<?>)obj).getName();
	return String.valueOf(obj);
	}

	public IllegalAccessException makeAccessException(String message, Object from) {
	message = message + ": "+ toString();
	if (from != null) {
	if (from == MethodHandles.publicLookup()) {
	message += ", from public Lookup";
	} else {
	Module m;
	Class<?> plc;
	if (from instanceof MethodHandles.Lookup lookup) {
	from = lookup.lookupClass();
	m = lookup.lookupClass().getModule();
	plc = lookup.previousLookupClass();
	} else {
	m = ((Class<?>)from).getModule();
	plc = null;
	}
	message += ", from " + from + " (" + m + ")";
	if (plc != null) {
	message += ", previous lookup " +
	plc.getName() + " (" + plc.getModule() + ")";
	}
	}
	}
	return new IllegalAccessException(message);
	}
	private String message() {
	if (isResolved())
	return "no access";
	else if (isConstructor())
	return "no such constructor";
	else if (isMethod())
	return "no such method";
	else
	return "no such field";
	}
	public ReflectiveOperationException makeAccessException() {
	String message = message() + ": "+ toString();
	ReflectiveOperationException ex;
	if (isResolved() \|\| !(resolution instanceof NoSuchMethodError \|\|
	resolution instanceof NoSuchFieldError))
	ex = new IllegalAccessException(message);
	else if (isConstructor())
	ex = new NoSuchMethodException(message);
	else if (isMethod())
	ex = new NoSuchMethodException(message);
	else
	ex = new NoSuchFieldException(message);
	if (resolution instanceof Throwable)
	ex.initCause((Throwable) resolution);
	return ex;
	}

	/** Actually making a query requires an access check. */
	/non-public/
	static Factory getFactory() {
	return Factory.INSTANCE;
	}
	/** A factory type for resolving member names with the help of the VM.
	* TBD: Define access-safe public constructors for this factory.
	*/
	/non-public/
	static class Factory {
	private Factory() { } // singleton pattern
	static Factory INSTANCE = new Factory();

	private static int ALLOWED_FLAGS = ALL_KINDS;

	/// Queries
	List<MemberName> getMembers(Class<?> defc,
	String matchName, Object matchType,
	int matchFlags, Class<?> lookupClass) {
	matchFlags &= ALLOWED_FLAGS;
	String matchSig = null;
	if (matchType != null) {
	matchSig = BytecodeDescriptor.unparse(matchType);
	if (matchSig.startsWith("("))
	matchFlags &= ~(ALL_KINDS & ~IS_INVOCABLE);
	else
	matchFlags &= ~(ALL_KINDS & ~IS_FIELD);
	}
	final int BUF_MAX = 0x2000;
	int len1 = matchName == null ? 10 : matchType == null ? 4 : 1;
	MemberName[] buf = newMemberBuffer(len1);
	int totalCount = 0;
	ArrayList<MemberName[]> bufs = null;
	int bufCount = 0;
	for (;;) {
	bufCount = MethodHandleNatives.getMembers(defc,
	matchName, matchSig, matchFlags,
	lookupClass,
	totalCount, buf);
	if (bufCount <= buf.length) {
	if (bufCount < 0) bufCount = 0;
	totalCount += bufCount;
	break;
	}
	// JVM returned to us with an intentional overflow!
	totalCount += buf.length;
	int excess = bufCount - buf.length;
	if (bufs == null) bufs = new ArrayList<>(1);
	bufs.add(buf);
	int len2 = buf.length;
	len2 = Math.max(len2, excess);
	len2 = Math.max(len2, totalCount / 4);
	buf = newMemberBuffer(Math.min(BUF_MAX, len2));
	}
	ArrayList<MemberName> result = new ArrayList<>(totalCount);
	if (bufs != null) {
	for (MemberName[] buf0 : bufs) {
	Collections.addAll(result, buf0);
	}
	}
	for (int i = 0; i < bufCount; i++) {
	result.add(buf[i]);
	}
	// Signature matching is not the same as type matching, since
	// one signature might correspond to several types.
	// So if matchType is a Class or MethodType, refilter the results.
	if (matchType != null && matchType != matchSig) {
	for (Iterator<MemberName> it = result.iterator(); it.hasNext();) {
	MemberName m = it.next();
	if (!matchType.equals(m.getType()))
	it.remove();
	}
	}
	return result;
	}
	/** Produce a resolved version of the given member.
	* Super types are searched (for inherited members) if {@code searchSupers} is true.
	* Access checking is performed on behalf of the given {@code lookupClass}.
	* If lookup fails or access is not permitted, null is returned.
	* Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
	*/
	private MemberName resolve(byte refKind, MemberName ref, Class<?> lookupClass, int allowedModes,
	boolean speculativeResolve) {
	MemberName m = ref.clone(); // JVM will side-effect the ref
	assert(refKind == m.getReferenceKind());
	try {
	// There are 4 entities in play here:
	// * LC: lookupClass
	// * REFC: symbolic reference class (MN.clazz before resolution);
	// * DEFC: resolved method holder (MN.clazz after resolution);
	// * PTYPES: parameter types (MN.type)
	//
	// What we care about when resolving a MemberName is consistency between DEFC and PTYPES.
	// We do type alias (TA) checks on DEFC to ensure that. DEFC is not known until the JVM
	// finishes the resolution, so do TA checks right after MHN.resolve() is over.
	//
	// All parameters passed by a caller are checked against MH type (PTYPES) on every invocation,
	// so it is safe to call a MH from any context.
	//
	// REFC view on PTYPES doesn't matter, since it is used only as a starting point for resolution and doesn't
	// participate in method selection.
	m = MethodHandleNatives.resolve(m, lookupClass, allowedModes, speculativeResolve);
	if (m == null && speculativeResolve) {
	return null;
	}
	m.checkForTypeAlias(m.getDeclaringClass());
	m.resolution = null;
	} catch (ClassNotFoundException \| LinkageError ex) {
	// JVM reports that the "bytecode behavior" would get an error
	assert(!m.isResolved());
	m.resolution = ex;
	return m;
	}
	assert(m.referenceKindIsConsistent());
	m.initResolved(true);
	assert(m.vminfoIsConsistent());
	return m;
	}
	/** Produce a resolved version of the given member.
	* Super types are searched (for inherited members) if {@code searchSupers} is true.
	* Access checking is performed on behalf of the given {@code lookupClass}.
	* If lookup fails or access is not permitted, a {@linkplain ReflectiveOperationException} is thrown.
	* Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
	*/
	public <NoSuchMemberException extends ReflectiveOperationException>
	MemberName resolveOrFail(byte refKind, MemberName m,
	Class<?> lookupClass, int allowedModes,
	Class<NoSuchMemberException> nsmClass)
	throws IllegalAccessException, NoSuchMemberException {
	assert lookupClass != null \|\| allowedModes == LM_TRUSTED;
	MemberName result = resolve(refKind, m, lookupClass, allowedModes, false);
	if (result.isResolved())
	return result;
	ReflectiveOperationException ex = result.makeAccessException();
	if (ex instanceof IllegalAccessException) throw (IllegalAccessException) ex;
	throw nsmClass.cast(ex);
	}
	/** Produce a resolved version of the given member.
	* Super types are searched (for inherited members) if {@code searchSupers} is true.
	* Access checking is performed on behalf of the given {@code lookupClass}.
	* If lookup fails or access is not permitted, return null.
	* Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
	*/
	public MemberName resolveOrNull(byte refKind, MemberName m, Class<?> lookupClass, int allowedModes) {
	assert lookupClass != null \|\| allowedModes == LM_TRUSTED;
	MemberName result = resolve(refKind, m, lookupClass, allowedModes, true);
	if (result != null && result.isResolved())
	return result;
	return null;
	}
	/** Return a list of all methods defined by the given class.
	* Super types are searched (for inherited members) if {@code searchSupers} is true.
	* Access checking is performed on behalf of the given {@code lookupClass}.
	* Inaccessible members are not added to the last.
	*/
	public List<MemberName> getMethods(Class<?> defc, boolean searchSupers,
	Class<?> lookupClass) {
	return getMethods(defc, searchSupers, null, null, lookupClass);
	}
	/** Return a list of matching methods defined by the given class.
	* Super types are searched (for inherited members) if {@code searchSupers} is true.
	* Returned methods will match the name (if not null) and the type (if not null).
	* Access checking is performed on behalf of the given {@code lookupClass}.
	* Inaccessible members are not added to the last.
	*/
	public List<MemberName> getMethods(Class<?> defc, boolean searchSupers,
	String name, MethodType type, Class<?> lookupClass) {
	int matchFlags = IS_METHOD \| (searchSupers ? SEARCH_ALL_SUPERS : 0);
	return getMembers(defc, name, type, matchFlags, lookupClass);
	}
	/** Return a list of all constructors defined by the given class.
	* Access checking is performed on behalf of the given {@code lookupClass}.
	* Inaccessible members are not added to the last.
	*/
	public List<MemberName> getConstructors(Class<?> defc, Class<?> lookupClass) {
	return getMembers(defc, null, null, IS_CONSTRUCTOR, lookupClass);
	}
	/** Return a list of all fields defined by the given class.
	* Super types are searched (for inherited members) if {@code searchSupers} is true.
	* Access checking is performed on behalf of the given {@code lookupClass}.
	* Inaccessible members are not added to the last.
	*/
	public List<MemberName> getFields(Class<?> defc, boolean searchSupers,
	Class<?> lookupClass) {
	return getFields(defc, searchSupers, null, null, lookupClass);
	}
	/** Return a list of all fields defined by the given class.
	* Super types are searched (for inherited members) if {@code searchSupers} is true.
	* Returned fields will match the name (if not null) and the type (if not null).
	* Access checking is performed on behalf of the given {@code lookupClass}.
	* Inaccessible members are not added to the last.
	*/
	public List<MemberName> getFields(Class<?> defc, boolean searchSupers,
	String name, Class<?> type, Class<?> lookupClass) {
	int matchFlags = IS_FIELD \| (searchSupers ? SEARCH_ALL_SUPERS : 0);
	return getMembers(defc, name, type, matchFlags, lookupClass);
	}
	/** Return a list of all nested types defined by the given class.
	* Super types are searched (for inherited members) if {@code searchSupers} is true.
	* Access checking is performed on behalf of the given {@code lookupClass}.
	* Inaccessible members are not added to the last.
	*/
	public List<MemberName> getNestedTypes(Class<?> defc, boolean searchSupers,
	Class<?> lookupClass) {
	int matchFlags = IS_TYPE \| (searchSupers ? SEARCH_ALL_SUPERS : 0);
	return getMembers(defc, null, null, matchFlags, lookupClass);
	}
	private static MemberName[] newMemberBuffer(int length) {
	MemberName[] buf = new MemberName[length];
	// fill the buffer with dummy structs for the JVM to fill in
	for (int i = 0; i < length; i++)
	buf[i] = new MemberName();
	return buf;
	}
	}
	}

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