/*

  * Copyright (c) 2008, 2013, 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.Method;

 import java.lang.reflect.Member;

 import java.lang.reflect.Modifier;

 import java.util.ArrayList;

 import java.util.Arrays;

 import java.util.Collections;

 import java.util.Iterator;

 import java.util.List;

 import static java.lang.invoke.MethodHandleNatives.Constants.*;

 import static java.lang.invoke.MethodHandleStatics.*;

 import java.util.Objects;

 /**

  * 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

  * <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 decriptive.

  * 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 MemberName implements Member, Cloneable {

     private Class<?> clazz;       // class in which the method 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

     //@Injected JVM_Method* vmtarget;

     //@Injected int         vmindex;

     private 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) {

                 String sig = (String) type;

                 MethodType res = MethodType.fromMethodDescriptorString(sig, getClassLoader());

                 type = res;

             } else if (type instanceof Object[]) {

                 Object[] typeInfo = (Object[]) type;

                 Class<?>[] ptypes = (Class<?>[]) typeInfo[1];

                 Class<?> rtype = (Class<?>) typeInfo[0];

                 MethodType res = MethodType.methodType(rtype, ptypes);

                 type = res;

             }

             // Make sure type is a MethodType for racing threads.

             assert type instanceof MethodType : "bad method type " + type;

         }

         return (MethodType) type;

     }

     /** 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) {

                 String sig = (String) type;

                 MethodType mtype = MethodType.fromMethodDescriptorString("()"+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;

         switch (originalRefKind) {

         case REF_invokeInterface:

             // Looking up an interface method, can get (e.g.) Object.hashCode

             assert(refKind == REF_invokeVirtual ||

                    refKind == REF_invokeSpecial) : this;

             return true;

         case REF_invokeVirtual:

         case REF_newInvokeSpecial:

             // Looked up a virtual, can get (e.g.) final String.hashCode.

             assert(refKind == REF_invokeSpecial) : this;

             return true;

         }

         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);

 //        if (isConstructor() && refKind != REF_newInvokeSpecial)

 //            flags += (IS_METHOD - IS_CONSTRUCTOR);

 //        else if (refKind == REF_newInvokeSpecial && isMethod())

 //            flags += (IS_CONSTRUCTOR - IS_METHOD);

         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;

         final int negs = Modifier.STATIC;

         if (testFlags(bits | negs, bits) &&

             clazz == MethodHandle.class) {

             return isMethodHandleInvokeName(name);

         }

         return false;

     }

     public static boolean isMethodHandleInvokeName(String name) {

         return name.equals("invoke") || name.equals("invokeExact");

     }

     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

     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);

     }

     /** Utility method to query whether this member is accessible from a given lookup class. */

     public boolean isAccessibleFrom(Class<?> lookupClass) {

         return VerifyAccess.isMemberAccessible(this.getDeclaringClass(), this.getDeclaringClass(), flags,

                                                lookupClass, ALL_ACCESS|MethodHandles.Lookup.PACKAGE);

     }

     /** 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) {

         m.getClass();  // NPE check

         // 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;

             }

             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) {

         ctor.getClass();  // NPE check

         // 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) {

         fld.getClass();  // NPE check

         // 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;

     }

     // 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

     public int hashCode() {

         return Objects.hash(clazz, 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 field or type name from the given components:  Declaring class, name, type.

      *  The declaring class may be supplied as null if this is to be a bare name and type.

      *  The modifier flags default to zero.

      *  The resulting name will in an unresolved state.

      */

     public MemberName(Class<?> defClass, String name, Class<?> type, Void unused) {

         this(defClass, name, type, REF_NONE);

         initResolved(false);

     }

     /** Create a method or constructor name from the given components:  Declaring class, name, type, modifiers.

      *  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;

     }

     private void initResolved(boolean isResolved) {

         assert(this.resolution == null);  // not initialized yet!

         if (!isResolved)

             this.resolution = this;

         assert(isResolved() == isResolved);

     }

     void checkForTypeAlias() {

         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, clazz))  return;

             throw new LinkageError("bad method type alias: "+type+" not visible from "+clazz);

         } else {

             Class<?> type;

             if (this.type instanceof Class<?>)

                 type = (Class<?>) this.type;

             else

                 this.type = type = getFieldType();

             if (VerifyAccess.isTypeVisible(type, clazz))  return;

             throw new LinkageError("bad field type alias: "+type+" not visible from "+clazz);

         }

     }

     /** 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 = getName();

         buf.append(name == null ? "*" : name);

         Object type = getType();

         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)  message += ", from " + from;

         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);

                 }

             }

             result.addAll(Arrays.asList(buf).subList(0, bufCount));

             // 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) {

             MemberName m = ref.clone();  // JVM will side-effect the ref

             assert(refKind == m.getReferenceKind());

             try {

                 m = MethodHandleNatives.resolve(m, lookupClass);

                 m.checkForTypeAlias();

                 m.resolution = null;

             } catch (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,

                                  Class<NoSuchMemberException> nsmClass)

                 throws IllegalAccessException, NoSuchMemberException {

             MemberName result = resolve(refKind, m, lookupClass);

             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) {

             MemberName result = resolve(refKind, m, lookupClass);

             if (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;

         }

     }

 //    static {

 //        System.out.println("Hello world!  My methods are:");

 //        System.out.println(Factory.INSTANCE.getMethods(MemberName.class, true, null));

 //    }

 }