src/java.base/share/classes/java/lang/invoke/MemberName.java
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src/java.base/share/classes/java/lang/invoke/MemberName.java

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   1 /*
   2  * Copyright (c) 2008, 2013, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package java.lang.invoke;
  27 
  28 import sun.invoke.util.BytecodeDescriptor;
  29 import sun.invoke.util.VerifyAccess;
  30 
  31 import java.lang.reflect.Constructor;
  32 import java.lang.reflect.Field;
  33 import java.lang.reflect.Method;
  34 import java.lang.reflect.Member;
  35 import java.lang.reflect.Modifier;
  36 import java.util.ArrayList;
  37 import java.util.Arrays;
  38 import java.util.Collections;
  39 import java.util.Iterator;
  40 import java.util.List;

  41 import static java.lang.invoke.MethodHandleNatives.Constants.*;
  42 import static java.lang.invoke.MethodHandleStatics.*;

  43 import java.util.Objects;
  44 
  45 /**
  46  * A {@code MemberName} is a compact symbolic datum which fully characterizes
  47  * a method or field reference.
  48  * A member name refers to a field, method, constructor, or member type.
  49  * Every member name has a simple name (a string) and a type (either a Class or MethodType).
  50  * A member name may also have a non-null declaring class, or it may be simply
  51  * a naked name/type pair.
  52  * A member name may also have non-zero modifier flags.
  53  * Finally, a member name may be either resolved or unresolved.
  54  * If it is resolved, the existence of the named
  55  * <p>
  56  * Whether resolved or not, a member name provides no access rights or
  57  * invocation capability to its possessor.  It is merely a compact
  58  * representation of all symbolic information necessary to link to
  59  * and properly use the named member.
  60  * <p>
  61  * When resolved, a member name's internal implementation may include references to JVM metadata.
  62  * This representation is stateless and only descriptive.
  63  * It provides no private information and no capability to use the member.
  64  * <p>
  65  * By contrast, a {@linkplain java.lang.reflect.Method} contains fuller information
  66  * about the internals of a method (except its bytecodes) and also
  67  * allows invocation.  A MemberName is much lighter than a Method,
  68  * since it contains about 7 fields to the 16 of Method (plus its sub-arrays),
  69  * and those seven fields omit much of the information in Method.
  70  * @author jrose
  71  */
  72 /*non-public*/ final class MemberName implements Member, Cloneable {

  73     private Class<?> clazz;       // class in which the method is defined
  74     private String   name;        // may be null if not yet materialized
  75     private Object   type;        // may be null if not yet materialized
  76     private int      flags;       // modifier bits; see reflect.Modifier
  77     //@Injected JVM_Method* vmtarget;
  78     //@Injected int         vmindex;
  79     private Object   resolution;  // if null, this guy is resolved
  80 






































































































































































































  81     /** Return the declaring class of this member.
  82      *  In the case of a bare name and type, the declaring class will be null.
  83      */
  84     public Class<?> getDeclaringClass() {
  85         return clazz;
  86     }
  87 
  88     /** Utility method producing the class loader of the declaring class. */
  89     public ClassLoader getClassLoader() {
  90         return clazz.getClassLoader();
  91     }
  92 
  93     /** Return the simple name of this member.
  94      *  For a type, it is the same as {@link Class#getSimpleName}.
  95      *  For a method or field, it is the simple name of the member.
  96      *  For a constructor, it is always {@code "&lt;init&gt;"}.
  97      */
  98     public String getName() {
  99         if (name == null) {
 100             expandFromVM();


 462     }
 463     /** Query whether this member is a type. */
 464     public boolean isType() {
 465         return testAllFlags(IS_TYPE);
 466     }
 467     /** Utility method to query whether this member is neither public, private, nor protected. */
 468     public boolean isPackage() {
 469         return !testAnyFlags(ALL_ACCESS);
 470     }
 471     /** Query whether this member has a CallerSensitive annotation. */
 472     public boolean isCallerSensitive() {
 473         return testAllFlags(CALLER_SENSITIVE);
 474     }
 475 
 476     /** Utility method to query whether this member is accessible from a given lookup class. */
 477     public boolean isAccessibleFrom(Class<?> lookupClass) {
 478         return VerifyAccess.isMemberAccessible(this.getDeclaringClass(), this.getDeclaringClass(), flags,
 479                                                lookupClass, ALL_ACCESS|MethodHandles.Lookup.PACKAGE);
 480     }
 481 
 482     /** Initialize a query.   It is not resolved. */
 483     private void init(Class<?> defClass, String name, Object type, int flags) {
 484         // defining class is allowed to be null (for a naked name/type pair)
 485         //name.toString();  // null check
 486         //type.equals(type);  // null check
 487         // fill in fields:
 488         this.clazz = defClass;
 489         this.name = name;
 490         this.type = type;
 491         this.flags = flags;
 492         assert(testAnyFlags(ALL_KINDS));
 493         assert(this.resolution == null);  // nobody should have touched this yet
 494         //assert(referenceKindIsConsistent());  // do this after resolution
 495     }
 496 
 497     /**
 498      * Calls down to the VM to fill in the fields.  This method is
 499      * synchronized to avoid racing calls.
 500      */
 501     private void expandFromVM() {
 502         if (type != null) {
 503             return;
 504         }
 505         if (!isResolved()) {
 506             return;
 507         }
 508         MethodHandleNatives.expand(this);
 509     }
 510 
 511     // Capturing information from the Core Reflection API:
 512     private static int flagsMods(int flags, int mods, byte refKind) {
 513         assert((flags & RECOGNIZED_MODIFIERS) == 0);
 514         assert((mods & ~RECOGNIZED_MODIFIERS) == 0);
 515         assert((refKind & ~MN_REFERENCE_KIND_MASK) == 0);
 516         return flags | mods | (refKind << MN_REFERENCE_KIND_SHIFT);
 517     }
 518     /** Create a name for the given reflected method.  The resulting name will be in a resolved state. */
 519     public MemberName(Method m) {
 520         this(m, false);
 521     }
 522     @SuppressWarnings("LeakingThisInConstructor")
 523     public MemberName(Method m, boolean wantSpecial) {
 524         m.getClass();  // NPE check
 525         // fill in vmtarget, vmindex while we have m in hand:
 526         MethodHandleNatives.init(this, m);
 527         if (clazz == null) {  // MHN.init failed
 528             if (m.getDeclaringClass() == MethodHandle.class &&
 529                 isMethodHandleInvokeName(m.getName())) {
 530                 // The JVM did not reify this signature-polymorphic instance.
 531                 // Need a special case here.
 532                 // See comments on MethodHandleNatives.linkMethod.
 533                 MethodType type = MethodType.methodType(m.getReturnType(), m.getParameterTypes());
 534                 int flags = flagsMods(IS_METHOD, m.getModifiers(), REF_invokeVirtual);
 535                 init(MethodHandle.class, m.getName(), type, flags);
 536                 if (isMethodHandleInvoke())
 537                     return;
 538             }
 539             throw new LinkageError(m.toString());
 540         }
 541         assert(isResolved() && this.clazz != null);
 542         this.name = m.getName();
 543         if (this.type == null)
 544             this.type = new Object[] { m.getReturnType(), m.getParameterTypes() };
 545         if (wantSpecial) {
 546             if (isAbstract())
 547                 throw new AbstractMethodError(this.toString());
 548             if (getReferenceKind() == REF_invokeVirtual)
 549                 changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual);
 550             else if (getReferenceKind() == REF_invokeInterface)
 551                 // invokeSpecial on a default method
 552                 changeReferenceKind(REF_invokeSpecial, REF_invokeInterface);
 553         }
 554     }
 555     public MemberName asSpecial() {
 556         switch (getReferenceKind()) {
 557         case REF_invokeSpecial:     return this;
 558         case REF_invokeVirtual:     return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual);
 559         case REF_invokeInterface:   return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeInterface);
 560         case REF_newInvokeSpecial:  return clone().changeReferenceKind(REF_invokeSpecial, REF_newInvokeSpecial);
 561         }
 562         throw new IllegalArgumentException(this.toString());
 563     }
 564     /** If this MN is not REF_newInvokeSpecial, return a clone with that ref. kind.
 565      *  In that case it must already be REF_invokeSpecial.
 566      */
 567     public MemberName asConstructor() {
 568         switch (getReferenceKind()) {
 569         case REF_invokeSpecial:     return clone().changeReferenceKind(REF_newInvokeSpecial, REF_invokeSpecial);
 570         case REF_newInvokeSpecial:  return this;
 571         }
 572         throw new IllegalArgumentException(this.toString());
 573     }
 574     /** If this MN is a REF_invokeSpecial, return a clone with the "normal" kind


 580      *  undoes that change under the assumption that it occurred.)
 581      */
 582     public MemberName asNormalOriginal() {
 583         byte normalVirtual = clazz.isInterface() ? REF_invokeInterface : REF_invokeVirtual;
 584         byte refKind = getReferenceKind();
 585         byte newRefKind = refKind;
 586         MemberName result = this;
 587         switch (refKind) {
 588         case REF_invokeInterface:
 589         case REF_invokeVirtual:
 590         case REF_invokeSpecial:
 591             newRefKind = normalVirtual;
 592             break;
 593         }
 594         if (newRefKind == refKind)
 595             return this;
 596         result = clone().changeReferenceKind(newRefKind, refKind);
 597         assert(this.referenceKindIsConsistentWith(result.getReferenceKind()));
 598         return result;
 599     }
 600     /** Create a name for the given reflected constructor.  The resulting name will be in a resolved state. */
 601     @SuppressWarnings("LeakingThisInConstructor")
 602     public MemberName(Constructor<?> ctor) {
 603         ctor.getClass();  // NPE check
 604         // fill in vmtarget, vmindex while we have ctor in hand:
 605         MethodHandleNatives.init(this, ctor);
 606         assert(isResolved() && this.clazz != null);
 607         this.name = CONSTRUCTOR_NAME;
 608         if (this.type == null)
 609             this.type = new Object[] { void.class, ctor.getParameterTypes() };
 610     }
 611     /** Create a name for the given reflected field.  The resulting name will be in a resolved state.
 612      */
 613     public MemberName(Field fld) {
 614         this(fld, false);
 615     }
 616     @SuppressWarnings("LeakingThisInConstructor")
 617     public MemberName(Field fld, boolean makeSetter) {
 618         fld.getClass();  // NPE check
 619         // fill in vmtarget, vmindex while we have fld in hand:
 620         MethodHandleNatives.init(this, fld);
 621         assert(isResolved() && this.clazz != null);
 622         this.name = fld.getName();
 623         this.type = fld.getType();
 624         assert((REF_putStatic - REF_getStatic) == (REF_putField - REF_getField));
 625         byte refKind = this.getReferenceKind();
 626         assert(refKind == (isStatic() ? REF_getStatic : REF_getField));
 627         if (makeSetter) {
 628             changeReferenceKind((byte)(refKind + (REF_putStatic - REF_getStatic)), refKind);
 629         }
 630     }
 631     public boolean isGetter() {
 632         return MethodHandleNatives.refKindIsGetter(getReferenceKind());
 633     }
 634     public boolean isSetter() {
 635         return MethodHandleNatives.refKindIsSetter(getReferenceKind());
 636     }
 637     public MemberName asSetter() {
 638         byte refKind = getReferenceKind();
 639         assert(MethodHandleNatives.refKindIsGetter(refKind));
 640         assert((REF_putStatic - REF_getStatic) == (REF_putField - REF_getField));
 641         byte setterRefKind = (byte)(refKind + (REF_putField - REF_getField));
 642         return clone().changeReferenceKind(setterRefKind, refKind);
 643     }
 644     /** Create a name for the given class.  The resulting name will be in a resolved state. */
 645     public MemberName(Class<?> type) {
 646         init(type.getDeclaringClass(), type.getSimpleName(), type,
 647                 flagsMods(IS_TYPE, type.getModifiers(), REF_NONE));
 648         initResolved(true);
 649     }
 650 
 651     /**
 652      * Create a name for a signature-polymorphic invoker.
 653      * This is a placeholder for a signature-polymorphic instance
 654      * (of MH.invokeExact, etc.) that the JVM does not reify.
 655      * See comments on {@link MethodHandleNatives#linkMethod}.
 656      */
 657     static MemberName makeMethodHandleInvoke(String name, MethodType type) {
 658         return makeMethodHandleInvoke(name, type, MH_INVOKE_MODS | SYNTHETIC);
 659     }
 660     static MemberName makeMethodHandleInvoke(String name, MethodType type, int mods) {
 661         MemberName mem = new MemberName(MethodHandle.class, name, type, REF_invokeVirtual);
 662         mem.flags |= mods;  // it's not resolved, but add these modifiers anyway
 663         assert(mem.isMethodHandleInvoke()) : mem;
 664         return mem;
 665     }
 666 
 667     // bare-bones constructor; the JVM will fill it in
 668     MemberName() { }
 669 
 670     // locally useful cloner
 671     @Override protected MemberName clone() {
 672         try {
 673             return (MemberName) super.clone();
 674         } catch (CloneNotSupportedException ex) {
 675             throw newInternalError(ex);
 676         }
 677      }
 678 
 679     /** Get the definition of this member name.
 680      *  This may be in a super-class of the declaring class of this member.
 681      */
 682     public MemberName getDefinition() {
 683         if (!isResolved())  throw new IllegalStateException("must be resolved: "+this);
 684         if (isType())  return this;
 685         MemberName res = this.clone();
 686         res.clazz = null;
 687         res.type = null;
 688         res.name = null;
 689         res.resolution = res;


 698     }
 699     @Override
 700     public boolean equals(Object that) {
 701         return (that instanceof MemberName && this.equals((MemberName)that));
 702     }
 703 
 704     /** Decide if two member names have exactly the same symbolic content.
 705      *  Does not take into account any actual class members, so even if
 706      *  two member names resolve to the same actual member, they may
 707      *  be distinct references.
 708      */
 709     public boolean equals(MemberName that) {
 710         if (this == that)  return true;
 711         if (that == null)  return false;
 712         return this.clazz == that.clazz
 713                 && this.getReferenceKind() == that.getReferenceKind()
 714                 && Objects.equals(this.name, that.name)
 715                 && Objects.equals(this.getType(), that.getType());
 716     }
 717 
 718     // Construction from symbolic parts, for queries:
 719     /** Create a field or type name from the given components:
 720      *  Declaring class, name, type, reference kind.
 721      *  The declaring class may be supplied as null if this is to be a bare name and type.
 722      *  The resulting name will in an unresolved state.

 723      */
 724     public MemberName(Class<?> defClass, String name, Class<?> type, byte refKind) {
 725         init(defClass, name, type, flagsMods(IS_FIELD, 0, refKind));
 726         initResolved(false);
 727     }
 728     /** Create a method or constructor name from the given components:
 729      *  Declaring class, name, type, reference kind.
 730      *  It will be a constructor if and only if the name is {@code "&lt;init&gt;"}.
 731      *  The declaring class may be supplied as null if this is to be a bare name and type.
 732      *  The last argument is optional, a boolean which requests REF_invokeSpecial.
 733      *  The resulting name will in an unresolved state.
 734      */
 735     public MemberName(Class<?> defClass, String name, MethodType type, byte refKind) {
 736         int initFlags = (name != null && name.equals(CONSTRUCTOR_NAME) ? IS_CONSTRUCTOR : IS_METHOD);
 737         init(defClass, name, type, flagsMods(initFlags, 0, refKind));
 738         initResolved(false);
 739     }
 740     /** Create a method, constructor, or field name from the given components:
 741      *  Reference kind, declaring class, name, type.
 742      */
 743     public MemberName(byte refKind, Class<?> defClass, String name, Object type) {
 744         int kindFlags;
 745         if (MethodHandleNatives.refKindIsField(refKind)) {
 746             kindFlags = IS_FIELD;
 747             if (!(type instanceof Class))
 748                 throw newIllegalArgumentException("not a field type");
 749         } else if (MethodHandleNatives.refKindIsMethod(refKind)) {
 750             kindFlags = IS_METHOD;
 751             if (!(type instanceof MethodType))
 752                 throw newIllegalArgumentException("not a method type");
 753         } else if (refKind == REF_newInvokeSpecial) {
 754             kindFlags = IS_CONSTRUCTOR;
 755             if (!(type instanceof MethodType) ||
 756                 !CONSTRUCTOR_NAME.equals(name))
 757                 throw newIllegalArgumentException("not a constructor type or name");
 758         } else {
 759             throw newIllegalArgumentException("bad reference kind "+refKind);
 760         }
 761         init(defClass, name, type, flagsMods(kindFlags, 0, refKind));
 762         initResolved(false);











 763     }
 764     /** Query whether this member name is resolved to a non-static, non-final method.
 765      */
 766     public boolean hasReceiverTypeDispatch() {
 767         return MethodHandleNatives.refKindDoesDispatch(getReferenceKind());
 768     }
 769 
 770     /** Query whether this member name is resolved.
 771      *  A resolved member name is one for which the JVM has found
 772      *  a method, constructor, field, or type binding corresponding exactly to the name.
 773      *  (Document?)
 774      */
 775     public boolean isResolved() {
 776         return resolution == null;
 777     }
 778 
 779     private void initResolved(boolean isResolved) {
 780         assert(this.resolution == null);  // not initialized yet!
 781         if (!isResolved)
 782             this.resolution = this;
 783         assert(isResolved() == isResolved);
 784     }
 785 
 786     void checkForTypeAlias() {
 787         if (isInvocable()) {
 788             MethodType type;
 789             if (this.type instanceof MethodType)
 790                 type = (MethodType) this.type;
 791             else
 792                 this.type = type = getMethodType();
 793             if (type.erase() == type)  return;
 794             if (VerifyAccess.isTypeVisible(type, clazz))  return;
 795             throw new LinkageError("bad method type alias: "+type+" not visible from "+clazz);
 796         } else {
 797             Class<?> type;
 798             if (this.type instanceof Class<?>)
 799                 type = (Class<?>) this.type;
 800             else
 801                 this.type = type = getFieldType();
 802             if (VerifyAccess.isTypeVisible(type, clazz))  return;
 803             throw new LinkageError("bad field type alias: "+type+" not visible from "+clazz);
 804         }
 805     }


 945                     MemberName m = it.next();
 946                     if (!matchType.equals(m.getType()))
 947                         it.remove();
 948                 }
 949             }
 950             return result;
 951         }
 952         /** Produce a resolved version of the given member.
 953          *  Super types are searched (for inherited members) if {@code searchSupers} is true.
 954          *  Access checking is performed on behalf of the given {@code lookupClass}.
 955          *  If lookup fails or access is not permitted, null is returned.
 956          *  Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
 957          */
 958         private MemberName resolve(byte refKind, MemberName ref, Class<?> lookupClass) {
 959             MemberName m = ref.clone();  // JVM will side-effect the ref
 960             assert(refKind == m.getReferenceKind());
 961             try {
 962                 m = MethodHandleNatives.resolve(m, lookupClass);
 963                 m.checkForTypeAlias();
 964                 m.resolution = null;

 965             } catch (LinkageError ex) {
 966                 // JVM reports that the "bytecode behavior" would get an error
 967                 assert(!m.isResolved());
 968                 m.resolution = ex;
 969                 return m;
 970             }
 971             assert(m.referenceKindIsConsistent());
 972             m.initResolved(true);
 973             assert(m.vminfoIsConsistent());
 974             return m;
 975         }
 976         /** Produce a resolved version of the given member.
 977          *  Super types are searched (for inherited members) if {@code searchSupers} is true.
 978          *  Access checking is performed on behalf of the given {@code lookupClass}.
 979          *  If lookup fails or access is not permitted, a {@linkplain ReflectiveOperationException} is thrown.
 980          *  Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
 981          */
 982         public
 983         <NoSuchMemberException extends ReflectiveOperationException>
 984         MemberName resolveOrFail(byte refKind, MemberName m, Class<?> lookupClass,


1052             return getMembers(defc, name, type, matchFlags, lookupClass);
1053         }
1054         /** Return a list of all nested types defined by the given class.
1055          *  Super types are searched (for inherited members) if {@code searchSupers} is true.
1056          *  Access checking is performed on behalf of the given {@code lookupClass}.
1057          *  Inaccessible members are not added to the last.
1058          */
1059         public List<MemberName> getNestedTypes(Class<?> defc, boolean searchSupers,
1060                 Class<?> lookupClass) {
1061             int matchFlags = IS_TYPE | (searchSupers ? SEARCH_ALL_SUPERS : 0);
1062             return getMembers(defc, null, null, matchFlags, lookupClass);
1063         }
1064         private static MemberName[] newMemberBuffer(int length) {
1065             MemberName[] buf = new MemberName[length];
1066             // fill the buffer with dummy structs for the JVM to fill in
1067             for (int i = 0; i < length; i++)
1068                 buf[i] = new MemberName();
1069             return buf;
1070         }
1071     }
1072 
1073 //    static {
1074 //        System.out.println("Hello world!  My methods are:");
1075 //        System.out.println(Factory.INSTANCE.getMethods(MemberName.class, true, null));
1076 //    }
1077 }
   1 /*
   2  * Copyright (c) 2008, 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package java.lang.invoke;
  27 
  28 import sun.invoke.util.BytecodeDescriptor;
  29 import sun.invoke.util.VerifyAccess;
  30 
  31 import java.lang.reflect.Constructor;
  32 import java.lang.reflect.Field;
  33 import java.lang.reflect.Method;
  34 import java.lang.reflect.Member;
  35 import java.lang.reflect.Modifier;
  36 import java.util.ArrayList;
  37 import java.util.Arrays;
  38 import java.util.Collections;
  39 import java.util.Iterator;
  40 import java.util.List;
  41 
  42 import static java.lang.invoke.MethodHandleNatives.Constants.*;
  43 import static java.lang.invoke.MethodHandleStatics.*;
  44 
  45 import java.util.Objects;
  46 
  47 /**
  48  * A {@code MemberName} is a compact symbolic datum which fully characterizes
  49  * a method or field reference.
  50  * A member name refers to a field, method, constructor, or member type.
  51  * Every member name has a simple name (a string) and a type (either a Class or MethodType).
  52  * A member name may also have a non-null declaring class, or it may be simply
  53  * a naked name/type pair.
  54  * A member name may also have non-zero modifier flags.
  55  * Finally, a member name may be either resolved or unresolved.
  56  * If it is resolved, the existence of the named
  57  * <p>
  58  * Whether resolved or not, a member name provides no access rights or
  59  * invocation capability to its possessor.  It is merely a compact
  60  * representation of all symbolic information necessary to link to
  61  * and properly use the named member.
  62  * <p>
  63  * When resolved, a member name's internal implementation may include references to JVM metadata.
  64  * This representation is stateless and only descriptive.
  65  * It provides no private information and no capability to use the member.
  66  * <p>
  67  * By contrast, a {@linkplain java.lang.reflect.Method} contains fuller information
  68  * about the internals of a method (except its bytecodes) and also
  69  * allows invocation.  A MemberName is much lighter than a Method,
  70  * since it contains about 7 fields to the 16 of Method (plus its sub-arrays),
  71  * and those seven fields omit much of the information in Method.
  72  * @author jrose
  73  */
  74 @SuppressWarnings("rawtypes") //Comparable in next line
  75 /*non-public*/ final class MemberName implements Member, Comparable, Cloneable {
  76     private Class<?> clazz;       // class in which the method is defined
  77     private String   name;        // may be null if not yet materialized
  78     private Object   type;        // may be null if not yet materialized
  79     private int      flags;       // modifier bits; see reflect.Modifier
  80     //@Injected JVM_Method* vmtarget;
  81     //@Injected int         vmindex;
  82     private Object   resolution;  // if null, this guy is resolved
  83 
  84     // bare-bones constructor; the JVM will fill it in
  85     MemberName() { }
  86 
  87     /** Create a name for the given class.  The resulting name will be in a resolved state. */
  88     public MemberName(Class<?> type) {
  89         init(type.getDeclaringClass(), type.getSimpleName(), type,
  90                 flagsMods(IS_TYPE, type.getModifiers(), REF_NONE));
  91         initResolved(true);
  92     }
  93 
  94     // Construction from symbolic parts, for queries:
  95     /** Create a field or type name from the given components:
  96      *  Declaring class, name, type, reference kind.
  97      *  The declaring class may be supplied as null if this is to be a bare name and type.
  98      *  The resulting name will in an unresolved state.
  99      */
 100     public MemberName(Class<?> defClass, String name, Class<?> type, byte refKind) {
 101         init(defClass, name, type, flagsMods(IS_FIELD, 0, refKind));
 102         initResolved(false);
 103     }
 104 
 105     /** Create a field or type name from the given components:  Declaring class, name, type.
 106      *  The declaring class may be supplied as null if this is to be a bare name and type.
 107      *  The modifier flags default to zero.
 108      *  The resulting name will in an unresolved state.
 109      */
 110     public MemberName(Class<?> defClass, String name, Class<?> type, Void unused) {
 111         this(defClass, name, type, REF_NONE);
 112         initResolved(false);
 113     }
 114 
 115     /** Create a method or constructor name from the given components:  Declaring class, name, type, modifiers.
 116      *  It will be a constructor if and only if the name is {@code "&lt;init&gt;"}.
 117      *  The declaring class may be supplied as null if this is to be a bare name and type.
 118      *  The last argument is optional, a boolean which requests REF_invokeSpecial.
 119      *  The resulting name will in an unresolved state.
 120      */
 121     public MemberName(Class<?> defClass, String name, MethodType type, byte refKind) {
 122         int initFlags = (name != null && name.equals(CONSTRUCTOR_NAME) ? IS_CONSTRUCTOR : IS_METHOD);
 123         init(defClass, name, type, flagsMods(initFlags, 0, refKind));
 124         initResolved(false);
 125     }
 126 
 127     /** Create a method, constructor, or field name from the given components:
 128      *  Reference kind, declaring class, name, type.
 129      */
 130     public MemberName(byte refKind, Class<?> defClass, String name, Object type) {
 131         int kindFlags;
 132         if (MethodHandleNatives.refKindIsField(refKind)) {
 133             kindFlags = IS_FIELD;
 134             if (!(type instanceof Class))
 135                 throw newIllegalArgumentException("not a field type");
 136         } else if (MethodHandleNatives.refKindIsMethod(refKind)) {
 137             kindFlags = IS_METHOD;
 138             if (!(type instanceof MethodType))
 139                 throw newIllegalArgumentException("not a method type");
 140         } else if (refKind == REF_newInvokeSpecial) {
 141             kindFlags = IS_CONSTRUCTOR;
 142             if (!(type instanceof MethodType) ||
 143                 !CONSTRUCTOR_NAME.equals(name))
 144                 throw newIllegalArgumentException("not a constructor type or name");
 145         } else {
 146             throw newIllegalArgumentException("bad reference kind "+refKind);
 147         }
 148         init(defClass, name, type, flagsMods(kindFlags, 0, refKind));
 149         initResolved(false);
 150     }
 151 
 152     /** Create a name for the given reflected method.  The resulting name will be in a resolved state. */
 153     public static MemberName make(Method m) {
 154         return make(m, false);
 155     }
 156 
 157     @SuppressWarnings("LeakingThisInConstructor")
 158     private MemberName(Method m, boolean wantSpecial) {
 159         m.getClass();  // NPE check
 160         // fill in vmtarget, vmindex while we have m in hand:
 161         MethodHandleNatives.init(this, m);
 162         if (clazz == null) {  // MHN.init failed
 163             if (m.getDeclaringClass() == MethodHandle.class &&
 164                 isMethodHandleInvokeName(m.getName())) {
 165                 // The JVM did not reify this signature-polymorphic instance.
 166                 // Need a special case here.
 167                 // See comments on MethodHandleNatives.linkMethod.
 168                 MethodType type = MethodType.methodType(m.getReturnType(), m.getParameterTypes());
 169                 int flags = flagsMods(IS_METHOD, m.getModifiers(), REF_invokeVirtual);
 170                 init(MethodHandle.class, m.getName(), type, flags);
 171                 if (isMethodHandleInvoke()) {
 172                     return;
 173                 }
 174             }
 175             throw new LinkageError(m.toString());
 176         }
 177         assert(isResolved() && this.clazz != null);
 178         this.name = m.getName();
 179         if (this.type == null) {
 180             this.type = new Object[] { m.getReturnType(), m.getParameterTypes() };
 181         }
 182         if (wantSpecial) {
 183             if (isAbstract()) {
 184                 throw new AbstractMethodError(this.toString());
 185             }
 186             if (getReferenceKind() == REF_invokeVirtual) {
 187                 changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual);
 188             } else if (getReferenceKind() == REF_invokeInterface) {
 189                 // invokeSpecial on a default method
 190                 changeReferenceKind(REF_invokeSpecial, REF_invokeInterface);
 191             }
 192         }
 193     }
 194 
 195     public static MemberName make(Method m, boolean wantSpecial) {
 196         MemberName tmp = new MemberName(m, wantSpecial);
 197         // Unreflected member names are resolved so intern them here.
 198         return tmp.intern();
 199     }
 200 
 201     /**
 202      * Create a name for the given reflected constructor. The resulting name
 203      * will be in a resolved state.
 204      */
 205     @SuppressWarnings("LeakingThisInConstructor")
 206     private MemberName(Constructor<?> ctor) {
 207         ctor.getClass();  // NPE check
 208         // fill in vmtarget, vmindex while we have ctor in hand:
 209         MethodHandleNatives.init(this, ctor);
 210         assert(isResolved() && this.clazz != null);
 211         this.name = CONSTRUCTOR_NAME;
 212         if (this.type == null) {
 213             this.type = new Object[] { void.class, ctor.getParameterTypes() };
 214         }
 215     }
 216 
 217     static public MemberName make(Constructor<?> ctor) {
 218         MemberName tmp = new MemberName(ctor);
 219         // Unreflected member names are resolved so intern them here.
 220         return tmp.intern();
 221     }
 222 
 223 
 224     /** Create a name for the given reflected field.  The resulting name will be in a resolved state.
 225      */
 226     public static MemberName make(Field field) {
 227         return make(field, false);
 228     }
 229 
 230     @SuppressWarnings("LeakingThisInConstructor")
 231     private MemberName(Field field, boolean makeSetter) {
 232         field.getClass();  // NPE check
 233         // fill in vmtarget, vmindex while we have field in hand:
 234         MethodHandleNatives.init(this, field);
 235         assert(isResolved() && this.clazz != null);
 236         this.name = field.getName();
 237         this.type = field.getType();
 238         byte refKind = this.getReferenceKind();
 239         assert(refKind == (isStatic() ? REF_getStatic : REF_getField));
 240         if (makeSetter) {
 241             assert((REF_putStatic - REF_getStatic) == (REF_putField - REF_getField));
 242             changeReferenceKind((byte)(refKind + (REF_putStatic - REF_getStatic)), refKind);
 243         }
 244     }
 245 
 246     static public MemberName make(Field field, boolean makeSetter) {
 247         MemberName tmp = new MemberName(field, makeSetter);
 248         // Unreflected member names are resolved so intern them here.
 249         return tmp.intern();
 250     }
 251 
 252     /** Initialize a query.   It is not resolved. */
 253     private void init(Class<?> defClass, String name, Object type, int flags) {
 254         // defining class is allowed to be null (for a naked name/type pair)
 255         //name.toString();  // null check
 256         //type.equals(type);  // null check
 257         // fill in fields:
 258         this.clazz = defClass;
 259         this.name = name;
 260         this.type = type;
 261         this.flags = flags;
 262         assert(testAnyFlags(ALL_KINDS));
 263         assert(this.resolution == null);  // nobody should have touched this yet
 264         //assert(referenceKindIsConsistent());  // do this after resolution
 265     }
 266 
 267     private void initResolved(boolean isResolved) {
 268         assert(this.resolution == null);  // not initialized yet!
 269         if (!isResolved)
 270             this.resolution = this;
 271         assert(isResolved() == isResolved);
 272     }
 273 
 274     /**
 275      * Helper method to intern this member name in the declaring class' member name table.
 276      */
 277     @SuppressWarnings("unchecked")
 278     private MemberName intern() {
 279         return clazz.internMemberName(this);
 280     }
 281 
 282     /** Return the declaring class of this member.
 283      *  In the case of a bare name and type, the declaring class will be null.
 284      */
 285     public Class<?> getDeclaringClass() {
 286         return clazz;
 287     }
 288 
 289     /** Utility method producing the class loader of the declaring class. */
 290     public ClassLoader getClassLoader() {
 291         return clazz.getClassLoader();
 292     }
 293 
 294     /** Return the simple name of this member.
 295      *  For a type, it is the same as {@link Class#getSimpleName}.
 296      *  For a method or field, it is the simple name of the member.
 297      *  For a constructor, it is always {@code "&lt;init&gt;"}.
 298      */
 299     public String getName() {
 300         if (name == null) {
 301             expandFromVM();


 663     }
 664     /** Query whether this member is a type. */
 665     public boolean isType() {
 666         return testAllFlags(IS_TYPE);
 667     }
 668     /** Utility method to query whether this member is neither public, private, nor protected. */
 669     public boolean isPackage() {
 670         return !testAnyFlags(ALL_ACCESS);
 671     }
 672     /** Query whether this member has a CallerSensitive annotation. */
 673     public boolean isCallerSensitive() {
 674         return testAllFlags(CALLER_SENSITIVE);
 675     }
 676 
 677     /** Utility method to query whether this member is accessible from a given lookup class. */
 678     public boolean isAccessibleFrom(Class<?> lookupClass) {
 679         return VerifyAccess.isMemberAccessible(this.getDeclaringClass(), this.getDeclaringClass(), flags,
 680                                                lookupClass, ALL_ACCESS|MethodHandles.Lookup.PACKAGE);
 681     }
 682 















 683     /**
 684      * Calls down to the VM to fill in the fields.  This method is
 685      * synchronized to avoid racing calls.
 686      */
 687     private void expandFromVM() {
 688         if (type != null) {
 689             return;
 690         }
 691         if (!isResolved()) {
 692             return;
 693         }
 694         MethodHandleNatives.expand(this);
 695     }
 696 
 697     // Capturing information from the Core Reflection API:
 698     private static int flagsMods(int flags, int mods, byte refKind) {
 699         assert((flags & RECOGNIZED_MODIFIERS) == 0);
 700         assert((mods & ~RECOGNIZED_MODIFIERS) == 0);
 701         assert((refKind & ~MN_REFERENCE_KIND_MASK) == 0);
 702         return flags | mods | (refKind << MN_REFERENCE_KIND_SHIFT);
 703     }





































 704     public MemberName asSpecial() {
 705         switch (getReferenceKind()) {
 706         case REF_invokeSpecial:     return this;
 707         case REF_invokeVirtual:     return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual);
 708         case REF_invokeInterface:   return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeInterface);
 709         case REF_newInvokeSpecial:  return clone().changeReferenceKind(REF_invokeSpecial, REF_newInvokeSpecial);
 710         }
 711         throw new IllegalArgumentException(this.toString());
 712     }
 713     /** If this MN is not REF_newInvokeSpecial, return a clone with that ref. kind.
 714      *  In that case it must already be REF_invokeSpecial.
 715      */
 716     public MemberName asConstructor() {
 717         switch (getReferenceKind()) {
 718         case REF_invokeSpecial:     return clone().changeReferenceKind(REF_newInvokeSpecial, REF_invokeSpecial);
 719         case REF_newInvokeSpecial:  return this;
 720         }
 721         throw new IllegalArgumentException(this.toString());
 722     }
 723     /** If this MN is a REF_invokeSpecial, return a clone with the "normal" kind


 729      *  undoes that change under the assumption that it occurred.)
 730      */
 731     public MemberName asNormalOriginal() {
 732         byte normalVirtual = clazz.isInterface() ? REF_invokeInterface : REF_invokeVirtual;
 733         byte refKind = getReferenceKind();
 734         byte newRefKind = refKind;
 735         MemberName result = this;
 736         switch (refKind) {
 737         case REF_invokeInterface:
 738         case REF_invokeVirtual:
 739         case REF_invokeSpecial:
 740             newRefKind = normalVirtual;
 741             break;
 742         }
 743         if (newRefKind == refKind)
 744             return this;
 745         result = clone().changeReferenceKind(newRefKind, refKind);
 746         assert(this.referenceKindIsConsistentWith(result.getReferenceKind()));
 747         return result;
 748     }































 749     public boolean isGetter() {
 750         return MethodHandleNatives.refKindIsGetter(getReferenceKind());
 751     }
 752     public boolean isSetter() {
 753         return MethodHandleNatives.refKindIsSetter(getReferenceKind());
 754     }
 755     public MemberName asSetter() {
 756         byte refKind = getReferenceKind();
 757         assert(MethodHandleNatives.refKindIsGetter(refKind));
 758         assert((REF_putStatic - REF_getStatic) == (REF_putField - REF_getField));
 759         byte setterRefKind = (byte)(refKind + (REF_putField - REF_getField));
 760         return clone().changeReferenceKind(setterRefKind, refKind);
 761     }







 762     /**
 763      * Create a name for a signature-polymorphic invoker.
 764      * This is a placeholder for a signature-polymorphic instance
 765      * (of MH.invokeExact, etc.) that the JVM does not reify.
 766      * See comments on {@link MethodHandleNatives#linkMethod}.
 767      */
 768     static MemberName makeMethodHandleInvoke(String name, MethodType type) {
 769         return makeMethodHandleInvoke(name, type, MH_INVOKE_MODS | SYNTHETIC);
 770     }
 771     static MemberName makeMethodHandleInvoke(String name, MethodType type, int mods) {
 772         MemberName mem = new MemberName(MethodHandle.class, name, type, REF_invokeVirtual);
 773         mem.flags |= mods;  // it's not resolved, but add these modifiers anyway
 774         assert(mem.isMethodHandleInvoke()) : mem;
 775         return mem;
 776     }
 777 



 778     // locally useful cloner
 779     @Override protected MemberName clone() {
 780         try {
 781             return (MemberName) super.clone();
 782         } catch (CloneNotSupportedException ex) {
 783             throw newInternalError(ex);
 784         }
 785      }
 786 
 787     /** Get the definition of this member name.
 788      *  This may be in a super-class of the declaring class of this member.
 789      */
 790     public MemberName getDefinition() {
 791         if (!isResolved())  throw new IllegalStateException("must be resolved: "+this);
 792         if (isType())  return this;
 793         MemberName res = this.clone();
 794         res.clazz = null;
 795         res.type = null;
 796         res.name = null;
 797         res.resolution = res;


 806     }
 807     @Override
 808     public boolean equals(Object that) {
 809         return (that instanceof MemberName && this.equals((MemberName)that));
 810     }
 811 
 812     /** Decide if two member names have exactly the same symbolic content.
 813      *  Does not take into account any actual class members, so even if
 814      *  two member names resolve to the same actual member, they may
 815      *  be distinct references.
 816      */
 817     public boolean equals(MemberName that) {
 818         if (this == that)  return true;
 819         if (that == null)  return false;
 820         return this.clazz == that.clazz
 821                 && this.getReferenceKind() == that.getReferenceKind()
 822                 && Objects.equals(this.name, that.name)
 823                 && Objects.equals(this.getType(), that.getType());
 824     }
 825 
 826     @Override
 827     public int compareTo(Object o) {
 828         MemberName that = (MemberName) o;
 829 
 830         /* First try an equals.  This make the ordering checks easier because we
 831          * don't have to be precise and can use hash codes.
 832          */
 833         if (equals(that)) {
 834             return 0;

 835         }
 836 
 837         final int clazzDiff = this.clazz.hashCode() - that.clazz.hashCode();
 838         if (clazzDiff != 0) {
 839             return clazzDiff;







 840         }
 841 
 842         final int kindDiff = this.getReferenceKind() - that.getReferenceKind();
 843         if (kindDiff != 0) {
 844             return kindDiff;
















 845         }
 846 
 847         final int nameDiff = this.name.hashCode() - that.name.hashCode();
 848         if (nameDiff != 0) {
 849             return nameDiff;
 850         }
 851 
 852         final int typeDiff = this.getType().hashCode() - that.getType().hashCode();
 853         if (typeDiff != 0) {
 854             return typeDiff;
 855         }
 856 
 857         // In the unlikely case all values above are equal we just return 1.
 858         return 1;
 859     }
 860     /** Query whether this member name is resolved to a non-static, non-final method.
 861      */
 862     public boolean hasReceiverTypeDispatch() {
 863         return MethodHandleNatives.refKindDoesDispatch(getReferenceKind());
 864     }
 865 
 866     /** Query whether this member name is resolved.
 867      *  A resolved member name is one for which the JVM has found
 868      *  a method, constructor, field, or type binding corresponding exactly to the name.
 869      *  (Document?)
 870      */
 871     public boolean isResolved() {
 872         return resolution == null;
 873     }
 874 







 875     void checkForTypeAlias() {
 876         if (isInvocable()) {
 877             MethodType type;
 878             if (this.type instanceof MethodType)
 879                 type = (MethodType) this.type;
 880             else
 881                 this.type = type = getMethodType();
 882             if (type.erase() == type)  return;
 883             if (VerifyAccess.isTypeVisible(type, clazz))  return;
 884             throw new LinkageError("bad method type alias: "+type+" not visible from "+clazz);
 885         } else {
 886             Class<?> type;
 887             if (this.type instanceof Class<?>)
 888                 type = (Class<?>) this.type;
 889             else
 890                 this.type = type = getFieldType();
 891             if (VerifyAccess.isTypeVisible(type, clazz))  return;
 892             throw new LinkageError("bad field type alias: "+type+" not visible from "+clazz);
 893         }
 894     }


1034                     MemberName m = it.next();
1035                     if (!matchType.equals(m.getType()))
1036                         it.remove();
1037                 }
1038             }
1039             return result;
1040         }
1041         /** Produce a resolved version of the given member.
1042          *  Super types are searched (for inherited members) if {@code searchSupers} is true.
1043          *  Access checking is performed on behalf of the given {@code lookupClass}.
1044          *  If lookup fails or access is not permitted, null is returned.
1045          *  Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
1046          */
1047         private MemberName resolve(byte refKind, MemberName ref, Class<?> lookupClass) {
1048             MemberName m = ref.clone();  // JVM will side-effect the ref
1049             assert(refKind == m.getReferenceKind());
1050             try {
1051                 m = MethodHandleNatives.resolve(m, lookupClass);
1052                 m.checkForTypeAlias();
1053                 m.resolution = null;
1054                 m.intern();
1055             } catch (LinkageError ex) {
1056                 // JVM reports that the "bytecode behavior" would get an error
1057                 assert(!m.isResolved());
1058                 m.resolution = ex;
1059                 return m;
1060             }
1061             assert(m.referenceKindIsConsistent());
1062             m.initResolved(true);
1063             assert(m.vminfoIsConsistent());
1064             return m;
1065         }
1066         /** Produce a resolved version of the given member.
1067          *  Super types are searched (for inherited members) if {@code searchSupers} is true.
1068          *  Access checking is performed on behalf of the given {@code lookupClass}.
1069          *  If lookup fails or access is not permitted, a {@linkplain ReflectiveOperationException} is thrown.
1070          *  Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
1071          */
1072         public
1073         <NoSuchMemberException extends ReflectiveOperationException>
1074         MemberName resolveOrFail(byte refKind, MemberName m, Class<?> lookupClass,


1142             return getMembers(defc, name, type, matchFlags, lookupClass);
1143         }
1144         /** Return a list of all nested types defined by the given class.
1145          *  Super types are searched (for inherited members) if {@code searchSupers} is true.
1146          *  Access checking is performed on behalf of the given {@code lookupClass}.
1147          *  Inaccessible members are not added to the last.
1148          */
1149         public List<MemberName> getNestedTypes(Class<?> defc, boolean searchSupers,
1150                 Class<?> lookupClass) {
1151             int matchFlags = IS_TYPE | (searchSupers ? SEARCH_ALL_SUPERS : 0);
1152             return getMembers(defc, null, null, matchFlags, lookupClass);
1153         }
1154         private static MemberName[] newMemberBuffer(int length) {
1155             MemberName[] buf = new MemberName[length];
1156             // fill the buffer with dummy structs for the JVM to fill in
1157             for (int i = 0; i < length; i++)
1158                 buf[i] = new MemberName();
1159             return buf;
1160         }
1161     }





1162 }
src/java.base/share/classes/java/lang/invoke/MemberName.java
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