1 /*
   2  * Copyright (c) 2008, 2017, 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.Member;
  34 import java.lang.reflect.Method;
  35 import java.lang.reflect.Modifier;
  36 import java.util.ArrayList;
  37 import java.util.Collections;
  38 import java.util.Iterator;
  39 import java.util.List;
  40 import java.util.Objects;
  41 
  42 import static java.lang.invoke.MethodHandleNatives.Constants.*;
  43 import static java.lang.invoke.MethodHandleStatics.newIllegalArgumentException;
  44 import static java.lang.invoke.MethodHandleStatics.newInternalError;
  45 
  46 /**
  47  * A {@code MemberName} is a compact symbolic datum which fully characterizes
  48  * a method or field reference.
  49  * A member name refers to a field, method, constructor, or member type.
  50  * Every member name has a simple name (a string) and a type (either a Class or MethodType).
  51  * A member name may also have a non-null declaring class, or it may be simply
  52  * a naked name/type pair.
  53  * A member name may also have non-zero modifier flags.
  54  * Finally, a member name may be either resolved or unresolved.
  55  * If it is resolved, the existence of the named member has been determined by the JVM.
  56  * <p>
  57  * Whether resolved or not, a member name provides no access rights or
  58  * invocation capability to its possessor.  It is merely a compact
  59  * representation of all symbolic information necessary to link to
  60  * and properly use the named member.
  61  * <p>
  62  * When resolved, a member name's internal implementation may include references to JVM metadata.
  63  * This representation is stateless and only descriptive.
  64  * It provides no private information and no capability to use the member.
  65  * <p>
  66  * By contrast, a {@linkplain java.lang.reflect.Method} contains fuller information
  67  * about the internals of a method (except its bytecodes) and also
  68  * allows invocation.  A MemberName is much lighter than a Method,
  69  * since it contains about 7 fields to the 16 of Method (plus its sub-arrays),
  70  * and those seven fields omit much of the information in Method.
  71  * @author jrose
  72  */
  73 /*non-public*/ final class ResolvedMethodName {
  74     //@Injected JVM_Method* vmtarget;
  75     //@Injected Class<?>    vmholder;
  76 };
  77 
  78 /*non-public*/ final class MemberName implements Member, Cloneable {
  79     private Class<?> clazz;       // class in which the member is defined
  80     private String   name;        // may be null if not yet materialized
  81     private Object   type;        // may be null if not yet materialized
  82     private int      flags;       // modifier bits; see reflect.Modifier
  83     private ResolvedMethodName method;    // cached resolved method information
  84     //@Injected intptr_t       vmindex;   // vtable index or offset of resolved member
  85     Object   resolution;  // if null, this guy is resolved
  86 
  87     /** Return the declaring class of this member.
  88      *  In the case of a bare name and type, the declaring class will be null.
  89      */
  90     public Class<?> getDeclaringClass() {
  91         return clazz;
  92     }
  93 
  94     /** Utility method producing the class loader of the declaring class. */
  95     public ClassLoader getClassLoader() {
  96         return clazz.getClassLoader();
  97     }
  98 
  99     /** Return the simple name of this member.
 100      *  For a type, it is the same as {@link Class#getSimpleName}.
 101      *  For a method or field, it is the simple name of the member.
 102      *  For a constructor, it is always {@code "<init>"}.
 103      */
 104     public String getName() {
 105         if (name == null) {
 106             expandFromVM();
 107             if (name == null) {
 108                 return null;
 109             }
 110         }
 111         return name;
 112     }
 113 
 114     public MethodType getMethodOrFieldType() {
 115         if (isInvocable())
 116             return getMethodType();
 117         if (isGetter())
 118             return MethodType.methodType(getFieldType());
 119         if (isSetter())
 120             return MethodType.methodType(void.class, getFieldType());
 121         throw new InternalError("not a method or field: "+this);
 122     }
 123 
 124     /** Return the declared type of this member, which
 125      *  must be a method or constructor.
 126      */
 127     public MethodType getMethodType() {
 128         if (type == null) {
 129             expandFromVM();
 130             if (type == null) {
 131                 return null;
 132             }
 133         }
 134         if (!isInvocable()) {
 135             throw newIllegalArgumentException("not invocable, no method type");
 136         }
 137 
 138         {
 139             // Get a snapshot of type which doesn't get changed by racing threads.
 140             final Object type = this.type;
 141             if (type instanceof MethodType) {
 142                 return (MethodType) type;
 143             }
 144         }
 145 
 146         // type is not a MethodType yet.  Convert it thread-safely.
 147         synchronized (this) {
 148             if (type instanceof String) {
 149                 String sig = (String) type;
 150                 MethodType res = MethodType.fromDescriptor(sig, getClassLoader());
 151                 type = res;
 152             } else if (type instanceof Object[]) {
 153                 Object[] typeInfo = (Object[]) type;
 154                 Class<?>[] ptypes = (Class<?>[]) typeInfo[1];
 155                 Class<?> rtype = (Class<?>) typeInfo[0];
 156                 MethodType res = MethodType.makeImpl(rtype, ptypes, true);
 157                 type = res;
 158             }
 159             // Make sure type is a MethodType for racing threads.
 160             assert type instanceof MethodType : "bad method type " + type;
 161         }
 162         return (MethodType) type;
 163     }
 164 
 165     /** Return the descriptor of this member, which
 166      *  must be a method or constructor.
 167      */
 168     String getMethodDescriptor() {
 169         if (type == null) {
 170             expandFromVM();
 171             if (type == null) {
 172                 return null;
 173             }
 174         }
 175         if (!isInvocable()) {
 176             throw newIllegalArgumentException("not invocable, no method type");
 177         }
 178 
 179         // Get a snapshot of type which doesn't get changed by racing threads.
 180         final Object type = this.type;
 181         if (type instanceof String) {
 182             return (String) type;
 183         } else {
 184             return getMethodType().toMethodDescriptorString();
 185         }
 186     }
 187 
 188     /** Return the actual type under which this method or constructor must be invoked.
 189      *  For non-static methods or constructors, this is the type with a leading parameter,
 190      *  a reference to declaring class.  For static methods, it is the same as the declared type.
 191      */
 192     public MethodType getInvocationType() {
 193         MethodType itype = getMethodOrFieldType();
 194         if (isConstructor() && getReferenceKind() == REF_newInvokeSpecial)
 195             return itype.changeReturnType(clazz);
 196         if (!isStatic())
 197             return itype.insertParameterTypes(0, clazz);
 198         return itype;
 199     }
 200 
 201     /** Utility method producing the parameter types of the method type. */
 202     public Class<?>[] getParameterTypes() {
 203         return getMethodType().parameterArray();
 204     }
 205 
 206     /** Utility method producing the return type of the method type. */
 207     public Class<?> getReturnType() {
 208         return getMethodType().returnType();
 209     }
 210 
 211     /** Return the declared type of this member, which
 212      *  must be a field or type.
 213      *  If it is a type member, that type itself is returned.
 214      */
 215     public Class<?> getFieldType() {
 216         if (type == null) {
 217             expandFromVM();
 218             if (type == null) {
 219                 return null;
 220             }
 221         }
 222         if (isInvocable()) {
 223             throw newIllegalArgumentException("not a field or nested class, no simple type");
 224         }
 225 
 226         {
 227             // Get a snapshot of type which doesn't get changed by racing threads.
 228             final Object type = this.type;
 229             if (type instanceof Class<?>) {
 230                 return (Class<?>) type;
 231             }
 232         }
 233 
 234         // type is not a Class yet.  Convert it thread-safely.
 235         synchronized (this) {
 236             if (type instanceof String) {
 237                 String sig = (String) type;
 238                 MethodType mtype = MethodType.fromDescriptor("()"+sig, getClassLoader());
 239                 Class<?> res = mtype.returnType();
 240                 type = res;
 241             }
 242             // Make sure type is a Class for racing threads.
 243             assert type instanceof Class<?> : "bad field type " + type;
 244         }
 245         return (Class<?>) type;
 246     }
 247 
 248     /** Utility method to produce either the method type or field type of this member. */
 249     public Object getType() {
 250         return (isInvocable() ? getMethodType() : getFieldType());
 251     }
 252 
 253     /** Utility method to produce the signature of this member,
 254      *  used within the class file format to describe its type.
 255      */
 256     public String getSignature() {
 257         if (type == null) {
 258             expandFromVM();
 259             if (type == null) {
 260                 return null;
 261             }
 262         }
 263         if (isInvocable())
 264             return BytecodeDescriptor.unparse(getMethodType());
 265         else
 266             return BytecodeDescriptor.unparse(getFieldType());
 267     }
 268 
 269     /** Return the modifier flags of this member.
 270      *  @see java.lang.reflect.Modifier
 271      */
 272     public int getModifiers() {
 273         return (flags & RECOGNIZED_MODIFIERS);
 274     }
 275 
 276     /** Return the reference kind of this member, or zero if none.
 277      */
 278     public byte getReferenceKind() {
 279         return (byte) ((flags >>> MN_REFERENCE_KIND_SHIFT) & MN_REFERENCE_KIND_MASK);
 280     }
 281     private boolean referenceKindIsConsistent() {
 282         byte refKind = getReferenceKind();
 283         if (refKind == REF_NONE)  return isType();
 284         if (isField()) {
 285             assert(staticIsConsistent());
 286             assert(MethodHandleNatives.refKindIsField(refKind));
 287         } else if (isConstructor()) {
 288             assert(refKind == REF_newInvokeSpecial || refKind == REF_invokeSpecial);
 289         } else if (isMethod()) {
 290             assert(staticIsConsistent());
 291             assert(MethodHandleNatives.refKindIsMethod(refKind));
 292             if (clazz.isInterface())
 293                 assert(refKind == REF_invokeInterface ||
 294                        refKind == REF_invokeStatic    ||
 295                        refKind == REF_invokeSpecial   ||
 296                        refKind == REF_invokeVirtual && isObjectPublicMethod());
 297         } else {
 298             assert(false);
 299         }
 300         return true;
 301     }
 302     private boolean isObjectPublicMethod() {
 303         if (clazz == Object.class)  return true;
 304         MethodType mtype = getMethodType();
 305         if (name.equals("toString") && mtype.returnType() == String.class && mtype.parameterCount() == 0)
 306             return true;
 307         if (name.equals("hashCode") && mtype.returnType() == int.class && mtype.parameterCount() == 0)
 308             return true;
 309         if (name.equals("equals") && mtype.returnType() == boolean.class && mtype.parameterCount() == 1 && mtype.parameterType(0) == Object.class)
 310             return true;
 311         return false;
 312     }
 313     /*non-public*/ boolean referenceKindIsConsistentWith(int originalRefKind) {
 314         int refKind = getReferenceKind();
 315         if (refKind == originalRefKind)  return true;
 316         switch (originalRefKind) {
 317         case REF_invokeInterface:
 318             // Looking up an interface method, can get (e.g.) Object.hashCode
 319             assert(refKind == REF_invokeVirtual ||
 320                    refKind == REF_invokeSpecial) : this;
 321             return true;
 322         case REF_invokeVirtual:
 323         case REF_newInvokeSpecial:
 324             // Looked up a virtual, can get (e.g.) final String.hashCode.
 325             assert(refKind == REF_invokeSpecial) : this;
 326             return true;
 327         }
 328         assert(false) : this+" != "+MethodHandleNatives.refKindName((byte)originalRefKind);
 329         return true;
 330     }
 331     private boolean staticIsConsistent() {
 332         byte refKind = getReferenceKind();
 333         return MethodHandleNatives.refKindIsStatic(refKind) == isStatic() || getModifiers() == 0;
 334     }
 335     private boolean vminfoIsConsistent() {
 336         byte refKind = getReferenceKind();
 337         assert(isResolved());  // else don't call
 338         Object vminfo = MethodHandleNatives.getMemberVMInfo(this);
 339         assert(vminfo instanceof Object[]);
 340         long vmindex = (Long) ((Object[])vminfo)[0];
 341         Object vmtarget = ((Object[])vminfo)[1];
 342         if (MethodHandleNatives.refKindIsField(refKind)) {
 343             assert(vmindex >= 0) : vmindex + ":" + this;
 344             assert(vmtarget instanceof Class);
 345         } else {
 346             if (MethodHandleNatives.refKindDoesDispatch(refKind))
 347                 assert(vmindex >= 0) : vmindex + ":" + this;
 348             else
 349                 assert(vmindex < 0) : vmindex;
 350             assert(vmtarget instanceof MemberName) : vmtarget + " in " + this;
 351         }
 352         return true;
 353     }
 354 
 355     private MemberName changeReferenceKind(byte refKind, byte oldKind) {
 356         assert(getReferenceKind() == oldKind);
 357         assert(MethodHandleNatives.refKindIsValid(refKind));
 358         flags += (((int)refKind - oldKind) << MN_REFERENCE_KIND_SHIFT);
 359         return this;
 360     }
 361 
 362     private boolean testFlags(int mask, int value) {
 363         return (flags & mask) == value;
 364     }
 365     private boolean testAllFlags(int mask) {
 366         return testFlags(mask, mask);
 367     }
 368     private boolean testAnyFlags(int mask) {
 369         return !testFlags(mask, 0);
 370     }
 371 
 372     /** Utility method to query if this member is a method handle invocation (invoke or invokeExact).
 373      */
 374     public boolean isMethodHandleInvoke() {
 375         final int bits = MH_INVOKE_MODS &~ Modifier.PUBLIC;
 376         final int negs = Modifier.STATIC;
 377         if (testFlags(bits | negs, bits) &&
 378             clazz == MethodHandle.class) {
 379             return isMethodHandleInvokeName(name);
 380         }
 381         return false;
 382     }
 383     public static boolean isMethodHandleInvokeName(String name) {
 384         switch (name) {
 385         case "invoke":
 386         case "invokeExact":
 387             return true;
 388         default:
 389             return false;
 390         }
 391     }
 392     public boolean isVarHandleMethodInvoke() {
 393         final int bits = MH_INVOKE_MODS &~ Modifier.PUBLIC;
 394         final int negs = Modifier.STATIC;
 395         if (testFlags(bits | negs, bits) &&
 396             clazz == VarHandle.class) {
 397             return isVarHandleMethodInvokeName(name);
 398         }
 399         return false;
 400     }
 401     public static boolean isVarHandleMethodInvokeName(String name) {
 402         try {
 403             VarHandle.AccessMode.valueFromMethodName(name);
 404             return true;
 405         } catch (IllegalArgumentException e) {
 406             return false;
 407         }
 408     }
 409     private static final int MH_INVOKE_MODS = Modifier.NATIVE | Modifier.FINAL | Modifier.PUBLIC;
 410 
 411     /** Utility method to query the modifier flags of this member. */
 412     public boolean isStatic() {
 413         return Modifier.isStatic(flags);
 414     }
 415     /** Utility method to query the modifier flags of this member. */
 416     public boolean isPublic() {
 417         return Modifier.isPublic(flags);
 418     }
 419     /** Utility method to query the modifier flags of this member. */
 420     public boolean isPrivate() {
 421         return Modifier.isPrivate(flags);
 422     }
 423     /** Utility method to query the modifier flags of this member. */
 424     public boolean isProtected() {
 425         return Modifier.isProtected(flags);
 426     }
 427     /** Utility method to query the modifier flags of this member. */
 428     public boolean isFinal() {
 429         return Modifier.isFinal(flags);
 430     }
 431     /** Utility method to query whether this member or its defining class is final. */
 432     public boolean canBeStaticallyBound() {
 433         return Modifier.isFinal(flags | clazz.getModifiers());
 434     }
 435     /** Utility method to query the modifier flags of this member. */
 436     public boolean isVolatile() {
 437         return Modifier.isVolatile(flags);
 438     }
 439     /** Utility method to query the modifier flags of this member. */
 440     public boolean isAbstract() {
 441         return Modifier.isAbstract(flags);
 442     }
 443     /** Utility method to query the modifier flags of this member. */
 444     public boolean isNative() {
 445         return Modifier.isNative(flags);
 446     }
 447     // let the rest (native, volatile, transient, etc.) be tested via Modifier.isFoo
 448 
 449     // unofficial modifier flags, used by HotSpot:
 450     static final int BRIDGE    = 0x00000040;
 451     static final int VARARGS   = 0x00000080;
 452     static final int SYNTHETIC = 0x00001000;
 453     static final int ANNOTATION= 0x00002000;
 454     static final int ENUM      = 0x00004000;
 455     /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
 456     public boolean isBridge() {
 457         return testAllFlags(IS_METHOD | BRIDGE);
 458     }
 459     /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
 460     public boolean isVarargs() {
 461         return testAllFlags(VARARGS) && isInvocable();
 462     }
 463     /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
 464     public boolean isSynthetic() {
 465         return testAllFlags(SYNTHETIC);
 466     }
 467 
 468     static final String CONSTRUCTOR_NAME = "<init>";  // the ever-popular
 469 
 470     // modifiers exported by the JVM:
 471     static final int RECOGNIZED_MODIFIERS = 0xFFFF;
 472 
 473     // private flags, not part of RECOGNIZED_MODIFIERS:
 474     static final int
 475             IS_METHOD        = MN_IS_METHOD,        // method (not constructor)
 476             IS_CONSTRUCTOR   = MN_IS_CONSTRUCTOR,   // constructor
 477             IS_FIELD         = MN_IS_FIELD,         // field
 478             IS_TYPE          = MN_IS_TYPE,          // nested type
 479             CALLER_SENSITIVE = MN_CALLER_SENSITIVE; // @CallerSensitive annotation detected
 480 
 481     static final int ALL_ACCESS = Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED;
 482     static final int ALL_KINDS = IS_METHOD | IS_CONSTRUCTOR | IS_FIELD | IS_TYPE;
 483     static final int IS_INVOCABLE = IS_METHOD | IS_CONSTRUCTOR;
 484     static final int IS_FIELD_OR_METHOD = IS_METHOD | IS_FIELD;
 485     static final int SEARCH_ALL_SUPERS = MN_SEARCH_SUPERCLASSES | MN_SEARCH_INTERFACES;
 486 
 487     /** Utility method to query whether this member is a method or constructor. */
 488     public boolean isInvocable() {
 489         return testAnyFlags(IS_INVOCABLE);
 490     }
 491     /** Utility method to query whether this member is a method, constructor, or field. */
 492     public boolean isFieldOrMethod() {
 493         return testAnyFlags(IS_FIELD_OR_METHOD);
 494     }
 495     /** Query whether this member is a method. */
 496     public boolean isMethod() {
 497         return testAllFlags(IS_METHOD);
 498     }
 499     /** Query whether this member is a constructor. */
 500     public boolean isConstructor() {
 501         return testAllFlags(IS_CONSTRUCTOR);
 502     }
 503     /** Query whether this member is a field. */
 504     public boolean isField() {
 505         return testAllFlags(IS_FIELD);
 506     }
 507     /** Query whether this member is a type. */
 508     public boolean isType() {
 509         return testAllFlags(IS_TYPE);
 510     }
 511     /** Utility method to query whether this member is neither public, private, nor protected. */
 512     public boolean isPackage() {
 513         return !testAnyFlags(ALL_ACCESS);
 514     }
 515     /** Query whether this member has a CallerSensitive annotation. */
 516     public boolean isCallerSensitive() {
 517         return testAllFlags(CALLER_SENSITIVE);
 518     }
 519 
 520     /** Utility method to query whether this member is accessible from a given lookup class. */
 521     public boolean isAccessibleFrom(Class<?> lookupClass) {
 522         int mode = (ALL_ACCESS|MethodHandles.Lookup.PACKAGE|MethodHandles.Lookup.MODULE);
 523         return VerifyAccess.isMemberAccessible(this.getDeclaringClass(), this.getDeclaringClass(), flags,
 524                                                lookupClass, mode);
 525     }
 526 
 527     /**
 528      * Check if MemberName is a call to a method named {@code name} in class {@code declaredClass}.
 529      */
 530     public boolean refersTo(Class<?> declc, String n) {
 531         return clazz == declc && getName().equals(n);
 532     }
 533 
 534     /** Initialize a query.   It is not resolved. */
 535     private void init(Class<?> defClass, String name, Object type, int flags) {
 536         // defining class is allowed to be null (for a naked name/type pair)
 537         //name.toString();  // null check
 538         //type.equals(type);  // null check
 539         // fill in fields:
 540         this.clazz = defClass;
 541         this.name = name;
 542         this.type = type;
 543         this.flags = flags;
 544         assert(testAnyFlags(ALL_KINDS));
 545         assert(this.resolution == null);  // nobody should have touched this yet
 546         //assert(referenceKindIsConsistent());  // do this after resolution
 547     }
 548 
 549     /**
 550      * Calls down to the VM to fill in the fields.  This method is
 551      * synchronized to avoid racing calls.
 552      */
 553     private void expandFromVM() {
 554         if (type != null) {
 555             return;
 556         }
 557         if (!isResolved()) {
 558             return;
 559         }
 560         MethodHandleNatives.expand(this);
 561     }
 562 
 563     // Capturing information from the Core Reflection API:
 564     private static int flagsMods(int flags, int mods, byte refKind) {
 565         assert((flags & RECOGNIZED_MODIFIERS) == 0);
 566         assert((mods & ~RECOGNIZED_MODIFIERS) == 0);
 567         assert((refKind & ~MN_REFERENCE_KIND_MASK) == 0);
 568         return flags | mods | (refKind << MN_REFERENCE_KIND_SHIFT);
 569     }
 570     /** Create a name for the given reflected method.  The resulting name will be in a resolved state. */
 571     public MemberName(Method m) {
 572         this(m, false);
 573     }
 574     @SuppressWarnings("LeakingThisInConstructor")
 575     public MemberName(Method m, boolean wantSpecial) {
 576         Objects.requireNonNull(m);
 577         // fill in vmtarget, vmindex while we have m in hand:
 578         MethodHandleNatives.init(this, m);
 579         if (clazz == null) {  // MHN.init failed
 580             if (m.getDeclaringClass() == MethodHandle.class &&
 581                 isMethodHandleInvokeName(m.getName())) {
 582                 // The JVM did not reify this signature-polymorphic instance.
 583                 // Need a special case here.
 584                 // See comments on MethodHandleNatives.linkMethod.
 585                 MethodType type = MethodType.methodType(m.getReturnType(), m.getParameterTypes());
 586                 int flags = flagsMods(IS_METHOD, m.getModifiers(), REF_invokeVirtual);
 587                 init(MethodHandle.class, m.getName(), type, flags);
 588                 if (isMethodHandleInvoke())
 589                     return;
 590             }
 591             if (m.getDeclaringClass() == VarHandle.class &&
 592                 isVarHandleMethodInvokeName(m.getName())) {
 593                 // The JVM did not reify this signature-polymorphic instance.
 594                 // Need a special case here.
 595                 // See comments on MethodHandleNatives.linkMethod.
 596                 MethodType type = MethodType.methodType(m.getReturnType(), m.getParameterTypes());
 597                 int flags = flagsMods(IS_METHOD, m.getModifiers(), REF_invokeVirtual);
 598                 init(VarHandle.class, m.getName(), type, flags);
 599                 if (isVarHandleMethodInvoke())
 600                     return;
 601             }
 602             throw new LinkageError(m.toString());
 603         }
 604         assert(isResolved() && this.clazz != null);
 605         this.name = m.getName();
 606         if (this.type == null)
 607             this.type = new Object[] { m.getReturnType(), m.getParameterTypes() };
 608         if (wantSpecial) {
 609             if (isAbstract())
 610                 throw new AbstractMethodError(this.toString());
 611             if (getReferenceKind() == REF_invokeVirtual)
 612                 changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual);
 613             else if (getReferenceKind() == REF_invokeInterface)
 614                 // invokeSpecial on a default method
 615                 changeReferenceKind(REF_invokeSpecial, REF_invokeInterface);
 616         }
 617     }
 618     public MemberName asSpecial() {
 619         switch (getReferenceKind()) {
 620         case REF_invokeSpecial:     return this;
 621         case REF_invokeVirtual:     return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual);
 622         case REF_invokeInterface:   return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeInterface);
 623         case REF_newInvokeSpecial:  return clone().changeReferenceKind(REF_invokeSpecial, REF_newInvokeSpecial);
 624         }
 625         throw new IllegalArgumentException(this.toString());
 626     }
 627     /** If this MN is not REF_newInvokeSpecial, return a clone with that ref. kind.
 628      *  In that case it must already be REF_invokeSpecial.
 629      */
 630     public MemberName asConstructor() {
 631         switch (getReferenceKind()) {
 632         case REF_invokeSpecial:     return clone().changeReferenceKind(REF_newInvokeSpecial, REF_invokeSpecial);
 633         case REF_newInvokeSpecial:  return this;
 634         }
 635         throw new IllegalArgumentException(this.toString());
 636     }
 637     /** If this MN is a REF_invokeSpecial, return a clone with the "normal" kind
 638      *  REF_invokeVirtual; also switch either to REF_invokeInterface if clazz.isInterface.
 639      *  The end result is to get a fully virtualized version of the MN.
 640      *  (Note that resolving in the JVM will sometimes devirtualize, changing
 641      *  REF_invokeVirtual of a final to REF_invokeSpecial, and REF_invokeInterface
 642      *  in some corner cases to either of the previous two; this transform
 643      *  undoes that change under the assumption that it occurred.)
 644      */
 645     public MemberName asNormalOriginal() {
 646         byte normalVirtual = clazz.isInterface() ? REF_invokeInterface : REF_invokeVirtual;
 647         byte refKind = getReferenceKind();
 648         byte newRefKind = refKind;
 649         MemberName result = this;
 650         switch (refKind) {
 651         case REF_invokeInterface:
 652         case REF_invokeVirtual:
 653         case REF_invokeSpecial:
 654             newRefKind = normalVirtual;
 655             break;
 656         }
 657         if (newRefKind == refKind)
 658             return this;
 659         result = clone().changeReferenceKind(newRefKind, refKind);
 660         assert(this.referenceKindIsConsistentWith(result.getReferenceKind()));
 661         return result;
 662     }
 663     /** Create a name for the given reflected constructor.  The resulting name will be in a resolved state. */
 664     @SuppressWarnings("LeakingThisInConstructor")
 665     public MemberName(Constructor<?> ctor) {
 666         Objects.requireNonNull(ctor);
 667         // fill in vmtarget, vmindex while we have ctor in hand:
 668         MethodHandleNatives.init(this, ctor);
 669         assert(isResolved() && this.clazz != null);
 670         this.name = CONSTRUCTOR_NAME;
 671         if (this.type == null)
 672             this.type = new Object[] { void.class, ctor.getParameterTypes() };
 673     }
 674     /** Create a name for the given reflected field.  The resulting name will be in a resolved state.
 675      */
 676     public MemberName(Field fld) {
 677         this(fld, false);
 678     }
 679     @SuppressWarnings("LeakingThisInConstructor")
 680     public MemberName(Field fld, boolean makeSetter) {
 681         Objects.requireNonNull(fld);
 682         // fill in vmtarget, vmindex while we have fld in hand:
 683         MethodHandleNatives.init(this, fld);
 684         assert(isResolved() && this.clazz != null);
 685         this.name = fld.getName();
 686         this.type = fld.getType();
 687         assert((REF_putStatic - REF_getStatic) == (REF_putField - REF_getField));
 688         byte refKind = this.getReferenceKind();
 689         assert(refKind == (isStatic() ? REF_getStatic : REF_getField));
 690         if (makeSetter) {
 691             changeReferenceKind((byte)(refKind + (REF_putStatic - REF_getStatic)), refKind);
 692         }
 693     }
 694     public boolean isGetter() {
 695         return MethodHandleNatives.refKindIsGetter(getReferenceKind());
 696     }
 697     public boolean isSetter() {
 698         return MethodHandleNatives.refKindIsSetter(getReferenceKind());
 699     }
 700     public MemberName asSetter() {
 701         byte refKind = getReferenceKind();
 702         assert(MethodHandleNatives.refKindIsGetter(refKind));
 703         assert((REF_putStatic - REF_getStatic) == (REF_putField - REF_getField));
 704         byte setterRefKind = (byte)(refKind + (REF_putField - REF_getField));
 705         return clone().changeReferenceKind(setterRefKind, refKind);
 706     }
 707     /** Create a name for the given class.  The resulting name will be in a resolved state. */
 708     public MemberName(Class<?> type) {
 709         init(type.getDeclaringClass(), type.getSimpleName(), type,
 710                 flagsMods(IS_TYPE, type.getModifiers(), REF_NONE));
 711         initResolved(true);
 712     }
 713 
 714     /**
 715      * Create a name for a signature-polymorphic invoker.
 716      * This is a placeholder for a signature-polymorphic instance
 717      * (of MH.invokeExact, etc.) that the JVM does not reify.
 718      * See comments on {@link MethodHandleNatives#linkMethod}.
 719      */
 720     static MemberName makeMethodHandleInvoke(String name, MethodType type) {
 721         return makeMethodHandleInvoke(name, type, MH_INVOKE_MODS | SYNTHETIC);
 722     }
 723     static MemberName makeMethodHandleInvoke(String name, MethodType type, int mods) {
 724         MemberName mem = new MemberName(MethodHandle.class, name, type, REF_invokeVirtual);
 725         mem.flags |= mods;  // it's not resolved, but add these modifiers anyway
 726         assert(mem.isMethodHandleInvoke()) : mem;
 727         return mem;
 728     }
 729 
 730     static MemberName makeVarHandleMethodInvoke(String name, MethodType type) {
 731         return makeVarHandleMethodInvoke(name, type, MH_INVOKE_MODS | SYNTHETIC);
 732     }
 733     static MemberName makeVarHandleMethodInvoke(String name, MethodType type, int mods) {
 734         MemberName mem = new MemberName(VarHandle.class, name, type, REF_invokeVirtual);
 735         mem.flags |= mods;  // it's not resolved, but add these modifiers anyway
 736         assert(mem.isVarHandleMethodInvoke()) : mem;
 737         return mem;
 738     }
 739 
 740     // bare-bones constructor; the JVM will fill it in
 741     MemberName() { }
 742 
 743     // locally useful cloner
 744     @Override protected MemberName clone() {
 745         try {
 746             return (MemberName) super.clone();
 747         } catch (CloneNotSupportedException ex) {
 748             throw newInternalError(ex);
 749         }
 750      }
 751 
 752     /** Get the definition of this member name.
 753      *  This may be in a super-class of the declaring class of this member.
 754      */
 755     public MemberName getDefinition() {
 756         if (!isResolved())  throw new IllegalStateException("must be resolved: "+this);
 757         if (isType())  return this;
 758         MemberName res = this.clone();
 759         res.clazz = null;
 760         res.type = null;
 761         res.name = null;
 762         res.resolution = res;
 763         res.expandFromVM();
 764         assert(res.getName().equals(this.getName()));
 765         return res;
 766     }
 767 
 768     @Override
 769     @SuppressWarnings("deprecation")
 770     public int hashCode() {
 771         // Avoid autoboxing getReferenceKind(), since this is used early and will force
 772         // early initialization of Byte$ByteCache
 773         return Objects.hash(clazz, new Byte(getReferenceKind()), name, getType());
 774     }
 775 
 776     @Override
 777     public boolean equals(Object that) {
 778         return (that instanceof MemberName && this.equals((MemberName)that));
 779     }
 780 
 781     /** Decide if two member names have exactly the same symbolic content.
 782      *  Does not take into account any actual class members, so even if
 783      *  two member names resolve to the same actual member, they may
 784      *  be distinct references.
 785      */
 786     public boolean equals(MemberName that) {
 787         if (this == that)  return true;
 788         if (that == null)  return false;
 789         return this.clazz == that.clazz
 790                 && this.getReferenceKind() == that.getReferenceKind()
 791                 && Objects.equals(this.name, that.name)
 792                 && Objects.equals(this.getType(), that.getType());
 793     }
 794 
 795     // Construction from symbolic parts, for queries:
 796     /** Create a field or type name from the given components:
 797      *  Declaring class, name, type, reference kind.
 798      *  The declaring class may be supplied as null if this is to be a bare name and type.
 799      *  The resulting name will in an unresolved state.
 800      */
 801     public MemberName(Class<?> defClass, String name, Class<?> type, byte refKind) {
 802         init(defClass, name, type, flagsMods(IS_FIELD, 0, refKind));
 803         initResolved(false);
 804     }
 805     /** Create a method or constructor name from the given components:
 806      *  Declaring class, name, type, reference kind.
 807      *  It will be a constructor if and only if the name is {@code "<init>"}.
 808      *  The declaring class may be supplied as null if this is to be a bare name and type.
 809      *  The last argument is optional, a boolean which requests REF_invokeSpecial.
 810      *  The resulting name will in an unresolved state.
 811      */
 812     public MemberName(Class<?> defClass, String name, MethodType type, byte refKind) {
 813         int initFlags = (name != null && name.equals(CONSTRUCTOR_NAME) ? IS_CONSTRUCTOR : IS_METHOD);
 814         init(defClass, name, type, flagsMods(initFlags, 0, refKind));
 815         initResolved(false);
 816     }
 817     /** Create a method, constructor, or field name from the given components:
 818      *  Reference kind, declaring class, name, type.
 819      */
 820     public MemberName(byte refKind, Class<?> defClass, String name, Object type) {
 821         int kindFlags;
 822         if (MethodHandleNatives.refKindIsField(refKind)) {
 823             kindFlags = IS_FIELD;
 824             if (!(type instanceof Class))
 825                 throw newIllegalArgumentException("not a field type");
 826         } else if (MethodHandleNatives.refKindIsMethod(refKind)) {
 827             kindFlags = IS_METHOD;
 828             if (!(type instanceof MethodType))
 829                 throw newIllegalArgumentException("not a method type");
 830         } else if (refKind == REF_newInvokeSpecial) {
 831             kindFlags = IS_CONSTRUCTOR;
 832             if (!(type instanceof MethodType) ||
 833                 !CONSTRUCTOR_NAME.equals(name))
 834                 throw newIllegalArgumentException("not a constructor type or name");
 835         } else {
 836             throw newIllegalArgumentException("bad reference kind "+refKind);
 837         }
 838         init(defClass, name, type, flagsMods(kindFlags, 0, refKind));
 839         initResolved(false);
 840     }
 841     /** Query whether this member name is resolved to a non-static, non-final method.
 842      */
 843     public boolean hasReceiverTypeDispatch() {
 844         return MethodHandleNatives.refKindDoesDispatch(getReferenceKind());
 845     }
 846 
 847     /** Query whether this member name is resolved.
 848      *  A resolved member name is one for which the JVM has found
 849      *  a method, constructor, field, or type binding corresponding exactly to the name.
 850      *  (Document?)
 851      */
 852     public boolean isResolved() {
 853         return resolution == null;
 854     }
 855 
 856     void initResolved(boolean isResolved) {
 857         assert(this.resolution == null);  // not initialized yet!
 858         if (!isResolved)
 859             this.resolution = this;
 860         assert(isResolved() == isResolved);
 861     }
 862 
 863     void checkForTypeAlias(Class<?> refc) {
 864         if (isInvocable()) {
 865             MethodType type;
 866             if (this.type instanceof MethodType)
 867                 type = (MethodType) this.type;
 868             else
 869                 this.type = type = getMethodType();
 870             if (type.erase() == type)  return;
 871             if (VerifyAccess.isTypeVisible(type, refc))  return;
 872             throw new LinkageError("bad method type alias: "+type+" not visible from "+refc);
 873         } else {
 874             Class<?> type;
 875             if (this.type instanceof Class<?>)
 876                 type = (Class<?>) this.type;
 877             else
 878                 this.type = type = getFieldType();
 879             if (VerifyAccess.isTypeVisible(type, refc))  return;
 880             throw new LinkageError("bad field type alias: "+type+" not visible from "+refc);
 881         }
 882     }
 883 
 884 
 885     /** Produce a string form of this member name.
 886      *  For types, it is simply the type's own string (as reported by {@code toString}).
 887      *  For fields, it is {@code "DeclaringClass.name/type"}.
 888      *  For methods and constructors, it is {@code "DeclaringClass.name(ptype...)rtype"}.
 889      *  If the declaring class is null, the prefix {@code "DeclaringClass."} is omitted.
 890      *  If the member is unresolved, a prefix {@code "*."} is prepended.
 891      */
 892     @SuppressWarnings("LocalVariableHidesMemberVariable")
 893     @Override
 894     public String toString() {
 895         if (isType())
 896             return type.toString();  // class java.lang.String
 897         // else it is a field, method, or constructor
 898         StringBuilder buf = new StringBuilder();
 899         if (getDeclaringClass() != null) {
 900             buf.append(getName(clazz));
 901             buf.append('.');
 902         }
 903         String name = this.name; // avoid expanding from VM
 904         buf.append(name == null ? "*" : name);
 905         Object type = this.type; // avoid expanding from VM
 906         if (!isInvocable()) {
 907             buf.append('/');
 908             buf.append(type == null ? "*" : getName(type));
 909         } else {
 910             buf.append(type == null ? "(*)*" : getName(type));
 911         }
 912         byte refKind = getReferenceKind();
 913         if (refKind != REF_NONE) {
 914             buf.append('/');
 915             buf.append(MethodHandleNatives.refKindName(refKind));
 916         }
 917         //buf.append("#").append(System.identityHashCode(this));
 918         return buf.toString();
 919     }
 920     private static String getName(Object obj) {
 921         if (obj instanceof Class<?>)
 922             return ((Class<?>)obj).getName();
 923         return String.valueOf(obj);
 924     }
 925 
 926     public IllegalAccessException makeAccessException(String message, Object from) {
 927         message = message + ": "+ toString();
 928         if (from != null)  {
 929             if (from == MethodHandles.publicLookup()) {
 930                 message += ", from public Lookup";
 931             } else {
 932                 Module m;
 933                 if (from instanceof MethodHandles.Lookup) {
 934                     MethodHandles.Lookup lookup = (MethodHandles.Lookup)from;
 935                     m = lookup.lookupClass().getModule();
 936                 } else {
 937                     m = from.getClass().getModule();
 938                 }
 939                 message += ", from " + from + " (" + m + ")";
 940             }
 941         }
 942         return new IllegalAccessException(message);
 943     }
 944     private String message() {
 945         if (isResolved())
 946             return "no access";
 947         else if (isConstructor())
 948             return "no such constructor";
 949         else if (isMethod())
 950             return "no such method";
 951         else
 952             return "no such field";
 953     }
 954     public ReflectiveOperationException makeAccessException() {
 955         String message = message() + ": "+ toString();
 956         ReflectiveOperationException ex;
 957         if (isResolved() || !(resolution instanceof NoSuchMethodError ||
 958                               resolution instanceof NoSuchFieldError))
 959             ex = new IllegalAccessException(message);
 960         else if (isConstructor())
 961             ex = new NoSuchMethodException(message);
 962         else if (isMethod())
 963             ex = new NoSuchMethodException(message);
 964         else
 965             ex = new NoSuchFieldException(message);
 966         if (resolution instanceof Throwable)
 967             ex.initCause((Throwable) resolution);
 968         return ex;
 969     }
 970 
 971     /** Actually making a query requires an access check. */
 972     /*non-public*/ static Factory getFactory() {
 973         return Factory.INSTANCE;
 974     }
 975     /** A factory type for resolving member names with the help of the VM.
 976      *  TBD: Define access-safe public constructors for this factory.
 977      */
 978     /*non-public*/ static class Factory {
 979         private Factory() { } // singleton pattern
 980         static Factory INSTANCE = new Factory();
 981 
 982         private static int ALLOWED_FLAGS = ALL_KINDS;
 983 
 984         /// Queries
 985         List<MemberName> getMembers(Class<?> defc,
 986                 String matchName, Object matchType,
 987                 int matchFlags, Class<?> lookupClass) {
 988             matchFlags &= ALLOWED_FLAGS;
 989             String matchSig = null;
 990             if (matchType != null) {
 991                 matchSig = BytecodeDescriptor.unparse(matchType);
 992                 if (matchSig.startsWith("("))
 993                     matchFlags &= ~(ALL_KINDS & ~IS_INVOCABLE);
 994                 else
 995                     matchFlags &= ~(ALL_KINDS & ~IS_FIELD);
 996             }
 997             final int BUF_MAX = 0x2000;
 998             int len1 = matchName == null ? 10 : matchType == null ? 4 : 1;
 999             MemberName[] buf = newMemberBuffer(len1);
1000             int totalCount = 0;
1001             ArrayList<MemberName[]> bufs = null;
1002             int bufCount = 0;
1003             for (;;) {
1004                 bufCount = MethodHandleNatives.getMembers(defc,
1005                         matchName, matchSig, matchFlags,
1006                         lookupClass,
1007                         totalCount, buf);
1008                 if (bufCount <= buf.length) {
1009                     if (bufCount < 0)  bufCount = 0;
1010                     totalCount += bufCount;
1011                     break;
1012                 }
1013                 // JVM returned to us with an intentional overflow!
1014                 totalCount += buf.length;
1015                 int excess = bufCount - buf.length;
1016                 if (bufs == null)  bufs = new ArrayList<>(1);
1017                 bufs.add(buf);
1018                 int len2 = buf.length;
1019                 len2 = Math.max(len2, excess);
1020                 len2 = Math.max(len2, totalCount / 4);
1021                 buf = newMemberBuffer(Math.min(BUF_MAX, len2));
1022             }
1023             ArrayList<MemberName> result = new ArrayList<>(totalCount);
1024             if (bufs != null) {
1025                 for (MemberName[] buf0 : bufs) {
1026                     Collections.addAll(result, buf0);
1027                 }
1028             }
1029             for (int i = 0; i < bufCount; i++) {
1030                 result.add(buf[i]);
1031             }
1032             // Signature matching is not the same as type matching, since
1033             // one signature might correspond to several types.
1034             // So if matchType is a Class or MethodType, refilter the results.
1035             if (matchType != null && matchType != matchSig) {
1036                 for (Iterator<MemberName> it = result.iterator(); it.hasNext();) {
1037                     MemberName m = it.next();
1038                     if (!matchType.equals(m.getType()))
1039                         it.remove();
1040                 }
1041             }
1042             return result;
1043         }
1044         /** Produce a resolved version of the given member.
1045          *  Super types are searched (for inherited members) if {@code searchSupers} is true.
1046          *  Access checking is performed on behalf of the given {@code lookupClass}.
1047          *  If lookup fails or access is not permitted, null is returned.
1048          *  Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
1049          */
1050         private MemberName resolve(byte refKind, MemberName ref, Class<?> lookupClass,
1051                                    boolean speculativeResolve) {
1052             MemberName m = ref.clone();  // JVM will side-effect the ref
1053             assert(refKind == m.getReferenceKind());
1054             try {
1055                 // There are 4 entities in play here:
1056                 //   * LC: lookupClass
1057                 //   * REFC: symbolic reference class (MN.clazz before resolution);
1058                 //   * DEFC: resolved method holder (MN.clazz after resolution);
1059                 //   * PTYPES: parameter types (MN.type)
1060                 //
1061                 // What we care about when resolving a MemberName is consistency between DEFC and PTYPES.
1062                 // We do type alias (TA) checks on DEFC to ensure that. DEFC is not known until the JVM
1063                 // finishes the resolution, so do TA checks right after MHN.resolve() is over.
1064                 //
1065                 // All parameters passed by a caller are checked against MH type (PTYPES) on every invocation,
1066                 // so it is safe to call a MH from any context.
1067                 //
1068                 // REFC view on PTYPES doesn't matter, since it is used only as a starting point for resolution and doesn't
1069                 // participate in method selection.
1070                 m = MethodHandleNatives.resolve(m, lookupClass, speculativeResolve);
1071                 if (m == null && speculativeResolve) {
1072                     return null;
1073                 }
1074                 m.checkForTypeAlias(m.getDeclaringClass());
1075                 m.resolution = null;
1076             } catch (ClassNotFoundException | LinkageError ex) {
1077                 // JVM reports that the "bytecode behavior" would get an error
1078                 assert(!m.isResolved());
1079                 m.resolution = ex;
1080                 return m;
1081             }
1082             assert(m.referenceKindIsConsistent());
1083             m.initResolved(true);
1084             assert(m.vminfoIsConsistent());
1085             return m;
1086         }
1087         /** Produce a resolved version of the given member.
1088          *  Super types are searched (for inherited members) if {@code searchSupers} is true.
1089          *  Access checking is performed on behalf of the given {@code lookupClass}.
1090          *  If lookup fails or access is not permitted, a {@linkplain ReflectiveOperationException} is thrown.
1091          *  Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
1092          */
1093         public
1094         <NoSuchMemberException extends ReflectiveOperationException>
1095         MemberName resolveOrFail(byte refKind, MemberName m, Class<?> lookupClass,
1096                                  Class<NoSuchMemberException> nsmClass)
1097                 throws IllegalAccessException, NoSuchMemberException {
1098             MemberName result = resolve(refKind, m, lookupClass, false);
1099             if (result.isResolved())
1100                 return result;
1101             ReflectiveOperationException ex = result.makeAccessException();
1102             if (ex instanceof IllegalAccessException)  throw (IllegalAccessException) ex;
1103             throw nsmClass.cast(ex);
1104         }
1105         /** Produce a resolved version of the given member.
1106          *  Super types are searched (for inherited members) if {@code searchSupers} is true.
1107          *  Access checking is performed on behalf of the given {@code lookupClass}.
1108          *  If lookup fails or access is not permitted, return null.
1109          *  Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
1110          */
1111         public
1112         MemberName resolveOrNull(byte refKind, MemberName m, Class<?> lookupClass) {
1113             MemberName result = resolve(refKind, m, lookupClass, true);
1114             if (result != null && result.isResolved())
1115                 return result;
1116             return null;
1117         }
1118         /** Return a list of all methods defined by the given class.
1119          *  Super types are searched (for inherited members) if {@code searchSupers} is true.
1120          *  Access checking is performed on behalf of the given {@code lookupClass}.
1121          *  Inaccessible members are not added to the last.
1122          */
1123         public List<MemberName> getMethods(Class<?> defc, boolean searchSupers,
1124                 Class<?> lookupClass) {
1125             return getMethods(defc, searchSupers, null, null, lookupClass);
1126         }
1127         /** Return a list of matching methods defined by the given class.
1128          *  Super types are searched (for inherited members) if {@code searchSupers} is true.
1129          *  Returned methods will match the name (if not null) and the type (if not null).
1130          *  Access checking is performed on behalf of the given {@code lookupClass}.
1131          *  Inaccessible members are not added to the last.
1132          */
1133         public List<MemberName> getMethods(Class<?> defc, boolean searchSupers,
1134                 String name, MethodType type, Class<?> lookupClass) {
1135             int matchFlags = IS_METHOD | (searchSupers ? SEARCH_ALL_SUPERS : 0);
1136             return getMembers(defc, name, type, matchFlags, lookupClass);
1137         }
1138         /** Return a list of all constructors defined by the given class.
1139          *  Access checking is performed on behalf of the given {@code lookupClass}.
1140          *  Inaccessible members are not added to the last.
1141          */
1142         public List<MemberName> getConstructors(Class<?> defc, Class<?> lookupClass) {
1143             return getMembers(defc, null, null, IS_CONSTRUCTOR, lookupClass);
1144         }
1145         /** Return a list of all fields defined by the given class.
1146          *  Super types are searched (for inherited members) if {@code searchSupers} is true.
1147          *  Access checking is performed on behalf of the given {@code lookupClass}.
1148          *  Inaccessible members are not added to the last.
1149          */
1150         public List<MemberName> getFields(Class<?> defc, boolean searchSupers,
1151                 Class<?> lookupClass) {
1152             return getFields(defc, searchSupers, null, null, lookupClass);
1153         }
1154         /** Return a list of all fields defined by the given class.
1155          *  Super types are searched (for inherited members) if {@code searchSupers} is true.
1156          *  Returned fields will match the name (if not null) and the type (if not null).
1157          *  Access checking is performed on behalf of the given {@code lookupClass}.
1158          *  Inaccessible members are not added to the last.
1159          */
1160         public List<MemberName> getFields(Class<?> defc, boolean searchSupers,
1161                 String name, Class<?> type, Class<?> lookupClass) {
1162             int matchFlags = IS_FIELD | (searchSupers ? SEARCH_ALL_SUPERS : 0);
1163             return getMembers(defc, name, type, matchFlags, lookupClass);
1164         }
1165         /** Return a list of all nested types defined by the given class.
1166          *  Super types are searched (for inherited members) if {@code searchSupers} is true.
1167          *  Access checking is performed on behalf of the given {@code lookupClass}.
1168          *  Inaccessible members are not added to the last.
1169          */
1170         public List<MemberName> getNestedTypes(Class<?> defc, boolean searchSupers,
1171                 Class<?> lookupClass) {
1172             int matchFlags = IS_TYPE | (searchSupers ? SEARCH_ALL_SUPERS : 0);
1173             return getMembers(defc, null, null, matchFlags, lookupClass);
1174         }
1175         private static MemberName[] newMemberBuffer(int length) {
1176             MemberName[] buf = new MemberName[length];
1177             // fill the buffer with dummy structs for the JVM to fill in
1178             for (int i = 0; i < length; i++)
1179                 buf[i] = new MemberName();
1180             return buf;
1181         }
1182     }
1183 }