1 /*
2 * Copyright (c) 2008, 2023, 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 jdk.internal.value.PrimitiveClass;
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.Objects;
37
38 import static java.lang.invoke.MethodHandleNatives.Constants.*;
39 import static java.lang.invoke.MethodHandleStatics.newIllegalArgumentException;
40 import static java.lang.invoke.MethodHandleStatics.newInternalError;
41
42 /**
43 * A {@code MemberName} is a compact symbolic datum which fully characterizes
44 * a method or field reference.
45 * A member name refers to a field, method, constructor, or member type.
46 * Every member name has a simple name (a string) and a type (either a Class or MethodType).
47 * A member name may also have a non-null declaring class, or it may be simply
48 * a naked name/type pair.
49 * A member name may also have non-zero modifier flags.
50 * Finally, a member name may be either resolved or unresolved.
51 * If it is resolved, the existence of the named member has been determined by the JVM.
52 * <p>
53 * Whether resolved or not, a member name provides no access rights or
54 * invocation capability to its possessor. It is merely a compact
55 * representation of all symbolic information necessary to link to
56 * and properly use the named member.
57 * <p>
58 * When resolved, a member name's internal implementation may include references to JVM metadata.
59 * This representation is stateless and only descriptive.
60 * It provides no private information and no capability to use the member.
61 * <p>
62 * By contrast, a {@linkplain java.lang.reflect.Method} contains fuller information
63 * about the internals of a method (except its bytecodes) and also
64 * allows invocation. A MemberName is much lighter than a Method,
65 * since it contains about 7 fields to the 16 of Method (plus its sub-arrays),
66 * and those seven fields omit much of the information in Method.
67 * @author jrose
68 */
69
70 /*non-public*/
71 final class MemberName implements Member, Cloneable {
72 private Class<?> clazz; // class in which the member is defined
73 private String name; // may be null if not yet materialized
74 private Object type; // may be null if not yet materialized
75 private int flags; // modifier bits; see reflect.Modifier
76 private ResolvedMethodName method; // cached resolved method information
77 //@Injected intptr_t vmindex; // vtable index or offset of resolved member
78 Object resolution; // if null, this guy is resolved
79
80 /** Return the declaring class of this member.
81 * In the case of a bare name and type, the declaring class will be null.
82 */
83 public Class<?> getDeclaringClass() {
84 return clazz;
85 }
86
87 /** Utility method producing the class loader of the declaring class. */
88 public ClassLoader getClassLoader() {
89 return clazz.getClassLoader();
90 }
91
92 /** Return the simple name of this member.
93 * For a type, it is the same as {@link Class#getSimpleName}.
94 * For a method or field, it is the simple name of the member.
95 * For an identity object constructor, it is {@code "<init>"}.
96 * For a value class static factory method, it is {@code "<vnew>"}.
97 */
98 public String getName() {
99 if (name == null) {
100 expandFromVM();
101 if (name == null) {
102 return null;
103 }
104 }
105 return name;
106 }
107
108 public MethodType getMethodOrFieldType() {
109 if (isInvocable())
110 return getMethodType();
111 if (isGetter())
112 return MethodType.methodType(getFieldType());
113 if (isSetter())
114 return MethodType.methodType(void.class, getFieldType());
115 throw new InternalError("not a method or field: "+this);
116 }
117
118 /** Return the declared type of this member, which
119 * must be a method or constructor.
120 */
121 public MethodType getMethodType() {
122 if (type == null) {
123 expandFromVM();
124 if (type == null) {
125 return null;
126 }
127 }
128 if (!isInvocable()) {
129 throw newIllegalArgumentException("not invocable, no method type");
130 }
131
132 {
133 // Get a snapshot of type which doesn't get changed by racing threads.
134 final Object type = this.type;
135 if (type instanceof MethodType mt) {
136 return mt;
137 }
138 }
139
140 // type is not a MethodType yet. Convert it thread-safely.
141 synchronized (this) {
142 if (type instanceof String sig) {
143 MethodType res = MethodType.fromDescriptor(sig, getClassLoader());
144 type = res;
145 } else if (type instanceof Object[] typeInfo) {
146 Class<?>[] ptypes = (Class<?>[]) typeInfo[1];
147 Class<?> rtype = (Class<?>) typeInfo[0];
148 MethodType res = MethodType.methodType(rtype, ptypes, true);
149 type = res;
150 }
151 // Make sure type is a MethodType for racing threads.
152 assert type instanceof MethodType : "bad method type " + type;
153 }
154 return (MethodType) type;
155 }
156
157 /** Return the descriptor of this member, which
158 * must be a method or constructor.
159 */
160 String getMethodDescriptor() {
161 if (type == null) {
162 expandFromVM();
163 if (type == null) {
164 return null;
165 }
166 }
167 if (!isInvocable()) {
168 throw newIllegalArgumentException("not invocable, no method type");
169 }
170
171 // Get a snapshot of type which doesn't get changed by racing threads.
172 final Object type = this.type;
173 if (type instanceof String str) {
174 return str;
175 } else {
176 return getMethodType().toMethodDescriptorString();
177 }
178 }
179
180 /** Return the actual type under which this method or constructor must be invoked.
181 * For non-static methods or constructors, this is the type with a leading parameter,
182 * a reference to declaring class. For static methods, it is the same as the declared type.
183 */
184 public MethodType getInvocationType() {
185 MethodType itype = getMethodOrFieldType();
186 Class<?> c = PrimitiveClass.isPrimitiveClass(clazz) ? PrimitiveClass.asValueType(clazz) : clazz;
187 if (isObjectConstructor() && getReferenceKind() == REF_newInvokeSpecial)
188 return itype.changeReturnType(c);
189 if (!isStatic())
190 return itype.insertParameterTypes(0, c);
191 return itype;
192 }
193
194 /** Return the declared type of this member, which
195 * must be a field or type.
196 * If it is a type member, that type itself is returned.
197 */
198 public Class<?> getFieldType() {
199 if (type == null) {
200 expandFromVM();
201 if (type == null) {
202 return null;
203 }
204 }
205 if (isInvocable()) {
206 throw newIllegalArgumentException("not a field or nested class, no simple type");
207 }
208
209 {
210 // Get a snapshot of type which doesn't get changed by racing threads.
211 final Object type = this.type;
212 if (type instanceof Class<?> cl) {
213 return cl;
214 }
215 }
216
217 // type is not a Class yet. Convert it thread-safely.
218 synchronized (this) {
219 if (type instanceof String sig) {
220 MethodType mtype = MethodType.fromDescriptor("()"+sig, getClassLoader());
221 Class<?> res = mtype.returnType();
222 type = res;
223 }
224 // Make sure type is a Class for racing threads.
225 assert type instanceof Class<?> : "bad field type " + type;
226 }
227 return (Class<?>) type;
228 }
229
230 /** Utility method to produce either the method type or field type of this member. */
231 public Object getType() {
232 return (isInvocable() ? getMethodType() : getFieldType());
233 }
234
235 /** Return the modifier flags of this member.
236 * @see java.lang.reflect.Modifier
237 */
238 public int getModifiers() {
239 return (flags & RECOGNIZED_MODIFIERS);
240 }
241
242 /** Return the reference kind of this member, or zero if none.
243 */
244 public byte getReferenceKind() {
245 return (byte) ((flags >>> MN_REFERENCE_KIND_SHIFT) & MN_REFERENCE_KIND_MASK);
246 }
247 private boolean referenceKindIsConsistent() {
248 byte refKind = getReferenceKind();
249 if (refKind == REF_NONE) return isType();
250 if (isField()) {
251 assert(staticIsConsistent());
252 assert(MethodHandleNatives.refKindIsField(refKind));
253 } else if (isObjectConstructor()) {
254 assert(refKind == REF_newInvokeSpecial || refKind == REF_invokeSpecial);
255 } else if (isMethod()) {
256 assert(staticIsConsistent());
257 assert(MethodHandleNatives.refKindIsMethod(refKind));
258 if (clazz.isInterface())
259 assert(refKind == REF_invokeInterface ||
260 refKind == REF_invokeStatic ||
261 refKind == REF_invokeSpecial ||
262 refKind == REF_invokeVirtual && isObjectPublicMethod());
263 } else {
264 assert(false);
265 }
266 return true;
267 }
268 private boolean isObjectPublicMethod() {
269 if (clazz == Object.class) return true;
270 MethodType mtype = getMethodType();
271 if (name.equals("toString") && mtype.returnType() == String.class && mtype.parameterCount() == 0)
272 return true;
273 if (name.equals("hashCode") && mtype.returnType() == int.class && mtype.parameterCount() == 0)
274 return true;
275 if (name.equals("equals") && mtype.returnType() == boolean.class && mtype.parameterCount() == 1 && mtype.parameterType(0) == Object.class)
276 return true;
277 return false;
278 }
279
280 /*non-public*/
281 boolean referenceKindIsConsistentWith(int originalRefKind) {
282 int refKind = getReferenceKind();
283 if (refKind == originalRefKind) return true;
284 if (getClass().desiredAssertionStatus()) {
285 switch (originalRefKind) {
286 case REF_invokeInterface -> {
287 // Looking up an interface method, can get (e.g.) Object.hashCode
288 assert (refKind == REF_invokeVirtual || refKind == REF_invokeSpecial) : this;
289 }
290 case REF_invokeVirtual, REF_newInvokeSpecial -> {
291 // Looked up a virtual, can get (e.g.) final String.hashCode.
292 assert (refKind == REF_invokeSpecial) : this;
293 }
294 default -> {
295 assert (false) : this + " != " + MethodHandleNatives.refKindName((byte) originalRefKind);
296 }
297 }
298 }
299 return true;
300 }
301 private boolean staticIsConsistent() {
302 byte refKind = getReferenceKind();
303 return MethodHandleNatives.refKindIsStatic(refKind) == isStatic() || getModifiers() == 0;
304 }
305 private boolean vminfoIsConsistent() {
306 byte refKind = getReferenceKind();
307 assert(isResolved()); // else don't call
308 Object vminfo = MethodHandleNatives.getMemberVMInfo(this);
309 assert(vminfo instanceof Object[]);
310 long vmindex = (Long) ((Object[])vminfo)[0];
311 Object vmtarget = ((Object[])vminfo)[1];
312 if (MethodHandleNatives.refKindIsField(refKind)) {
313 assert(vmindex >= 0) : vmindex + ":" + this;
314 assert(vmtarget instanceof Class);
315 } else {
316 if (MethodHandleNatives.refKindDoesDispatch(refKind))
317 assert(vmindex >= 0) : vmindex + ":" + this;
318 else
319 assert(vmindex < 0) : vmindex;
320 assert(vmtarget instanceof MemberName) : vmtarget + " in " + this;
321 }
322 return true;
323 }
324
325 private MemberName changeReferenceKind(byte refKind, byte oldKind) {
326 assert(getReferenceKind() == oldKind && MethodHandleNatives.refKindIsValid(refKind));
327 flags += (((int)refKind - oldKind) << MN_REFERENCE_KIND_SHIFT);
328 return this;
329 }
330
331 private boolean matchingFlagsSet(int mask, int flags) {
332 return (this.flags & mask) == flags;
333 }
334 private boolean allFlagsSet(int flags) {
335 return (this.flags & flags) == flags;
336 }
337 private boolean anyFlagSet(int flags) {
338 return (this.flags & flags) != 0;
339 }
340
341 /** Utility method to query if this member is a method handle invocation (invoke or invokeExact).
342 */
343 public boolean isMethodHandleInvoke() {
344 final int bits = MH_INVOKE_MODS &~ Modifier.PUBLIC;
345 final int negs = Modifier.STATIC;
346 if (matchingFlagsSet(bits | negs, bits) && clazz == MethodHandle.class) {
347 return isMethodHandleInvokeName(name);
348 }
349 return false;
350 }
351 public static boolean isMethodHandleInvokeName(String name) {
352 return switch (name) {
353 case "invoke", "invokeExact" -> true;
354 default -> false;
355 };
356 }
357 public boolean isVarHandleMethodInvoke() {
358 final int bits = MH_INVOKE_MODS &~ Modifier.PUBLIC;
359 final int negs = Modifier.STATIC;
360 if (matchingFlagsSet(bits | negs, bits) && clazz == VarHandle.class) {
361 return isVarHandleMethodInvokeName(name);
362 }
363 return false;
364 }
365 public static boolean isVarHandleMethodInvokeName(String name) {
366 try {
367 VarHandle.AccessMode.valueFromMethodName(name);
368 return true;
369 } catch (IllegalArgumentException e) {
370 return false;
371 }
372 }
373 private static final int MH_INVOKE_MODS = Modifier.NATIVE | Modifier.FINAL | Modifier.PUBLIC;
374
375 /** Utility method to query the modifier flags of this member. */
376 public boolean isStatic() {
377 return Modifier.isStatic(flags);
378 }
379 /** Utility method to query the modifier flags of this member. */
380 public boolean isPublic() {
381 return Modifier.isPublic(flags);
382 }
383 /** Utility method to query the modifier flags of this member. */
384 public boolean isPrivate() {
385 return Modifier.isPrivate(flags);
386 }
387 /** Utility method to query the modifier flags of this member. */
388 public boolean isProtected() {
389 return Modifier.isProtected(flags);
390 }
391 /** Utility method to query the modifier flags of this member. */
392 public boolean isFinal() {
393 // all fields declared in a value type are effectively final
394 assert(!clazz.isValue() || !isField() || Modifier.isFinal(flags));
395 return Modifier.isFinal(flags);
396 }
397 /** Utility method to query whether this member or its defining class is final. */
398 public boolean canBeStaticallyBound() {
399 return Modifier.isFinal(flags | clazz.getModifiers());
400 }
401 /** Utility method to query the modifier flags of this member. */
402 public boolean isVolatile() {
403 return Modifier.isVolatile(flags);
404 }
405 /** Utility method to query the modifier flags of this member. */
406 public boolean isAbstract() {
407 return Modifier.isAbstract(flags);
408 }
409 /** Utility method to query the modifier flags of this member. */
410 public boolean isNative() {
411 return Modifier.isNative(flags);
412 }
413 // let the rest (native, volatile, transient, etc.) be tested via Modifier.isFoo
414
415 // unofficial modifier flags, used by HotSpot:
416 static final int BRIDGE = 0x00000040;
417 static final int VARARGS = 0x00000080;
418 static final int SYNTHETIC = 0x00001000;
419 static final int ANNOTATION = 0x00002000;
420 static final int ENUM = 0x00004000;
421
422 /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
423 public boolean isBridge() {
424 return allFlagsSet(IS_METHOD | BRIDGE);
425 }
426 /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
427 public boolean isVarargs() {
428 return allFlagsSet(VARARGS) && isInvocable();
429 }
430 /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
431 public boolean isSynthetic() {
432 return allFlagsSet(SYNTHETIC);
433 }
434
435 /** Query whether this member is a flattened field */
436 public boolean isFlattened() { return (flags & MN_FLATTENED) == MN_FLATTENED; }
437
438 /** Query whether this member is a field of a primitive class. */
439 public boolean isInlineableField() {
440 if (isField()) {
441 Class<?> type = getFieldType();
442 return PrimitiveClass.isPrimitiveValueType(type) || (type.isValue() && !PrimitiveClass.isPrimitiveClass(type));
443 }
444 return false;
445 }
446
447 static final String CONSTRUCTOR_NAME = "<init>";
448 static final String VALUE_FACTORY_NAME = "<vnew>"; // the ever-popular
449
450 // modifiers exported by the JVM:
451 static final int RECOGNIZED_MODIFIERS = 0xFFFF;
452
453 // private flags, not part of RECOGNIZED_MODIFIERS:
454 static final int
455 IS_METHOD = MN_IS_METHOD, // method (not object constructor)
456 IS_OBJECT_CONSTRUCTOR = MN_IS_OBJECT_CONSTRUCTOR, // object constructor
457 IS_FIELD = MN_IS_FIELD, // field
458 IS_TYPE = MN_IS_TYPE, // nested type
459 CALLER_SENSITIVE = MN_CALLER_SENSITIVE, // @CallerSensitive annotation detected
460 TRUSTED_FINAL = MN_TRUSTED_FINAL; // trusted final field
461
462 static final int ALL_ACCESS = Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED;
463 static final int ALL_KINDS = IS_METHOD | IS_OBJECT_CONSTRUCTOR | IS_FIELD | IS_TYPE;
464 static final int IS_INVOCABLE = IS_METHOD | IS_OBJECT_CONSTRUCTOR;
465
466 /** Utility method to query whether this member is a method or constructor. */
467 public boolean isInvocable() {
468 return anyFlagSet(IS_INVOCABLE);
469 }
470 /** Query whether this member is a method. */
471 public boolean isMethod() {
472 return allFlagsSet(IS_METHOD);
473 }
474 /** Query whether this member is a constructor. */
475 public boolean isObjectConstructor() {
476 return allFlagsSet(IS_OBJECT_CONSTRUCTOR);
477 }
478 /** Query whether this member is an object constructor or static <init> factory */
479 public boolean isStaticValueFactoryMethod() {
480 return VALUE_FACTORY_NAME.equals(name) && isMethod();
481 }
482
483 /** Query whether this member is a field. */
484 public boolean isField() {
485 return allFlagsSet(IS_FIELD);
486 }
487 /** Query whether this member is a type. */
488 public boolean isType() {
489 return allFlagsSet(IS_TYPE);
490 }
491 /** Utility method to query whether this member is neither public, private, nor protected. */
492 public boolean isPackage() {
493 return !anyFlagSet(ALL_ACCESS);
494 }
495 /** Query whether this member has a CallerSensitive annotation. */
496 public boolean isCallerSensitive() {
497 return allFlagsSet(CALLER_SENSITIVE);
498 }
499 /** Query whether this member is a trusted final field. */
500 public boolean isTrustedFinalField() {
501 return allFlagsSet(TRUSTED_FINAL | IS_FIELD);
502 }
503
504 /**
505 * Check if MemberName is a call to a method named {@code name} in class {@code declaredClass}.
506 */
507 public boolean refersTo(Class<?> declc, String n) {
508 return clazz == declc && getName().equals(n);
509 }
510
511 /** Initialize a query. It is not resolved. */
512 private void init(Class<?> defClass, String name, Object type, int flags) {
513 // defining class is allowed to be null (for a naked name/type pair)
514 //name.toString(); // null check
515 //type.equals(type); // null check
516 // fill in fields:
517 this.clazz = defClass;
518 this.name = name;
519 this.type = type;
520 this.flags = flags;
521 assert(anyFlagSet(ALL_KINDS) && this.resolution == null); // nobody should have touched this yet
522 //assert(referenceKindIsConsistent()); // do this after resolution
523 }
524
525 /**
526 * Calls down to the VM to fill in the fields. This method is
527 * synchronized to avoid racing calls.
528 */
529 private void expandFromVM() {
530 if (type != null) {
531 return;
532 }
533 if (!isResolved()) {
534 return;
535 }
536 MethodHandleNatives.expand(this);
537 }
538
539 // Capturing information from the Core Reflection API:
540 private static int flagsMods(int flags, int mods, byte refKind) {
541 assert((flags & RECOGNIZED_MODIFIERS) == 0
542 && (mods & ~RECOGNIZED_MODIFIERS) == 0
543 && (refKind & ~MN_REFERENCE_KIND_MASK) == 0);
544 return flags | mods | (refKind << MN_REFERENCE_KIND_SHIFT);
545 }
546 /** Create a name for the given reflected method. The resulting name will be in a resolved state. */
547 public MemberName(Method m) {
548 this(m, false);
549 }
550 @SuppressWarnings("LeakingThisInConstructor")
551 public MemberName(Method m, boolean wantSpecial) {
552 Objects.requireNonNull(m);
553 // fill in vmtarget, vmindex while we have m in hand:
554 MethodHandleNatives.init(this, m);
555 if (clazz == null) { // MHN.init failed
556 if (m.getDeclaringClass() == MethodHandle.class &&
557 isMethodHandleInvokeName(m.getName())) {
558 // The JVM did not reify this signature-polymorphic instance.
559 // Need a special case here.
560 // See comments on MethodHandleNatives.linkMethod.
561 MethodType type = MethodType.methodType(m.getReturnType(), m.getParameterTypes());
562 int flags = flagsMods(IS_METHOD, m.getModifiers(), REF_invokeVirtual);
563 init(MethodHandle.class, m.getName(), type, flags);
564 if (isMethodHandleInvoke())
565 return;
566 }
567 if (m.getDeclaringClass() == VarHandle.class &&
568 isVarHandleMethodInvokeName(m.getName())) {
569 // The JVM did not reify this signature-polymorphic instance.
570 // Need a special case here.
571 // See comments on MethodHandleNatives.linkMethod.
572 MethodType type = MethodType.methodType(m.getReturnType(), m.getParameterTypes());
573 int flags = flagsMods(IS_METHOD, m.getModifiers(), REF_invokeVirtual);
574 init(VarHandle.class, m.getName(), type, flags);
575 if (isVarHandleMethodInvoke())
576 return;
577 }
578 throw new LinkageError(m.toString());
579 }
580 assert(isResolved());
581 this.name = m.getName();
582 if (this.type == null)
583 this.type = new Object[] { m.getReturnType(), m.getParameterTypes() };
584 if (wantSpecial) {
585 if (isAbstract())
586 throw new AbstractMethodError(this.toString());
587 if (getReferenceKind() == REF_invokeVirtual)
588 changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual);
589 else if (getReferenceKind() == REF_invokeInterface)
590 // invokeSpecial on a default method
591 changeReferenceKind(REF_invokeSpecial, REF_invokeInterface);
592 }
593 }
594 public MemberName asSpecial() {
595 switch (getReferenceKind()) {
596 case REF_invokeSpecial: return this;
597 case REF_invokeVirtual: return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual);
598 case REF_invokeInterface: return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeInterface);
599 case REF_newInvokeSpecial: return clone().changeReferenceKind(REF_invokeSpecial, REF_newInvokeSpecial);
600 }
601 throw new IllegalArgumentException(this.toString());
602 }
603 /** If this MN is not REF_newInvokeSpecial, return a clone with that ref. kind.
604 * In that case it must already be REF_invokeSpecial.
605 */
606 public MemberName asObjectConstructor() {
607 switch (getReferenceKind()) {
608 case REF_invokeSpecial: return clone().changeReferenceKind(REF_newInvokeSpecial, REF_invokeSpecial);
609 case REF_newInvokeSpecial: return this;
610 }
611 throw new IllegalArgumentException(this.toString());
612 }
613 /** If this MN is a REF_invokeSpecial, return a clone with the "normal" kind
614 * REF_invokeVirtual; also switch either to REF_invokeInterface if clazz.isInterface.
615 * The end result is to get a fully virtualized version of the MN.
616 * (Note that resolving in the JVM will sometimes devirtualize, changing
617 * REF_invokeVirtual of a final to REF_invokeSpecial, and REF_invokeInterface
618 * in some corner cases to either of the previous two; this transform
619 * undoes that change under the assumption that it occurred.)
620 */
621 public MemberName asNormalOriginal() {
622 byte refKind = getReferenceKind();
623 byte newRefKind = switch (refKind) {
624 case REF_invokeInterface,
625 REF_invokeVirtual,
626 REF_invokeSpecial -> clazz.isInterface() ? REF_invokeInterface : REF_invokeVirtual;
627 default -> refKind;
628 };
629 if (newRefKind == refKind)
630 return this;
631 MemberName result = clone().changeReferenceKind(newRefKind, refKind);
632 assert(this.referenceKindIsConsistentWith(result.getReferenceKind()));
633 return result;
634 }
635 /** Create a name for the given reflected constructor. The resulting name will be in a resolved state. */
636 @SuppressWarnings("LeakingThisInConstructor")
637 public MemberName(Constructor<?> ctor) {
638 Objects.requireNonNull(ctor);
639 // fill in vmtarget, vmindex while we have ctor in hand:
640 MethodHandleNatives.init(this, ctor);
641 assert(isResolved() && this.clazz != null);
642 this.name = this.clazz.isValue() ? VALUE_FACTORY_NAME : CONSTRUCTOR_NAME;
643 if (this.type == null) {
644 Class<?> rtype = void.class;
645 if (isStatic()) { // a value class static factory, not a true constructor
646 rtype = getDeclaringClass();
647 }
648 this.type = new Object[] { rtype, ctor.getParameterTypes() };
649 }
650 }
651 /** Create a name for the given reflected field. The resulting name will be in a resolved state.
652 */
653 public MemberName(Field fld) {
654 this(fld, false);
655 }
656 static {
657 // the following MemberName constructor relies on these ranges matching up
658 assert((REF_putStatic - REF_getStatic) == (REF_putField - REF_getField));
659 }
660 @SuppressWarnings("LeakingThisInConstructor")
661 public MemberName(Field fld, boolean makeSetter) {
662 Objects.requireNonNull(fld);
663 // fill in vmtarget, vmindex while we have fld in hand:
664 MethodHandleNatives.init(this, fld);
665 assert(isResolved() && this.clazz != null);
666 this.name = fld.getName();
667 this.type = fld.getType();
668 byte refKind = this.getReferenceKind();
669 assert(refKind == (isStatic() ? REF_getStatic : REF_getField));
670 if (makeSetter) {
671 changeReferenceKind((byte)(refKind + (REF_putStatic - REF_getStatic)), refKind);
672 }
673 }
674 public boolean isGetter() {
675 return MethodHandleNatives.refKindIsGetter(getReferenceKind());
676 }
677 public boolean isSetter() {
678 return MethodHandleNatives.refKindIsSetter(getReferenceKind());
679 }
680
681 /** Create a name for the given class. The resulting name will be in a resolved state. */
682 public MemberName(Class<?> type) {
683 init(type.getDeclaringClass(), type.getSimpleName(), type,
684 flagsMods(IS_TYPE, type.getModifiers(), REF_NONE));
685 initResolved(true);
686 }
687
688 /**
689 * Create a name for a signature-polymorphic invoker.
690 * This is a placeholder for a signature-polymorphic instance
691 * (of MH.invokeExact, etc.) that the JVM does not reify.
692 * See comments on {@link MethodHandleNatives#linkMethod}.
693 */
694 static MemberName makeMethodHandleInvoke(String name, MethodType type) {
695 return makeMethodHandleInvoke(name, type, MH_INVOKE_MODS | SYNTHETIC);
696 }
697 static MemberName makeMethodHandleInvoke(String name, MethodType type, int mods) {
698 MemberName mem = new MemberName(MethodHandle.class, name, type, REF_invokeVirtual);
699 mem.flags |= mods; // it's not resolved, but add these modifiers anyway
700 assert(mem.isMethodHandleInvoke()) : mem;
701 return mem;
702 }
703
704 static MemberName makeVarHandleMethodInvoke(String name, MethodType type) {
705 return makeVarHandleMethodInvoke(name, type, MH_INVOKE_MODS | SYNTHETIC);
706 }
707 static MemberName makeVarHandleMethodInvoke(String name, MethodType type, int mods) {
708 MemberName mem = new MemberName(VarHandle.class, name, type, REF_invokeVirtual);
709 mem.flags |= mods; // it's not resolved, but add these modifiers anyway
710 assert(mem.isVarHandleMethodInvoke()) : mem;
711 return mem;
712 }
713
714 // bare-bones constructor; the JVM will fill it in
715 MemberName() { }
716
717 // locally useful cloner
718 @Override protected MemberName clone() {
719 try {
720 return (MemberName) super.clone();
721 } catch (CloneNotSupportedException ex) {
722 throw newInternalError(ex);
723 }
724 }
725
726 /** Get the definition of this member name.
727 * This may be in a super-class of the declaring class of this member.
728 */
729 public MemberName getDefinition() {
730 if (!isResolved()) throw new IllegalStateException("must be resolved: "+this);
731 if (isType()) return this;
732 MemberName res = this.clone();
733 res.clazz = null;
734 res.type = null;
735 res.name = null;
736 res.resolution = res;
737 res.expandFromVM();
738 assert(res.getName().equals(this.getName()));
739 return res;
740 }
741
742 @Override
743 @SuppressWarnings({"deprecation", "removal"})
744 public int hashCode() {
745 // Avoid autoboxing getReferenceKind(), since this is used early and will force
746 // early initialization of Byte$ByteCache
747 return Objects.hash(clazz, new Byte(getReferenceKind()), name, getType());
748 }
749
750 @Override
751 public boolean equals(Object that) {
752 return that instanceof MemberName mn && this.equals(mn);
753 }
754
755 /** Decide if two member names have exactly the same symbolic content.
756 * Does not take into account any actual class members, so even if
757 * two member names resolve to the same actual member, they may
758 * be distinct references.
759 */
760 public boolean equals(MemberName that) {
761 if (this == that) return true;
762 if (that == null) return false;
763 return this.clazz == that.clazz
764 && this.getReferenceKind() == that.getReferenceKind()
765 && Objects.equals(this.name, that.name)
766 && Objects.equals(this.getType(), that.getType());
767 }
768
769 // Construction from symbolic parts, for queries:
770 /** Create a field or type name from the given components:
771 * Declaring class, name, type, reference kind.
772 * The declaring class may be supplied as null if this is to be a bare name and type.
773 * The resulting name will in an unresolved state.
774 */
775 public MemberName(Class<?> defClass, String name, Class<?> type, byte refKind) {
776 init(defClass, name, type, flagsMods(IS_FIELD, 0, refKind));
777 initResolved(false);
778 }
779 /** Create a method or constructor name from the given components:
780 * Declaring class, name, type, reference kind.
781 * It will be an object constructor if and only if the name is {@code "<init>"}.
782 * It will be a value class instance factory method if and only if the name is {@code "<vnew>"}.
783 * The declaring class may be supplied as null if this is to be a bare name and type.
784 * The last argument is optional, a boolean which requests REF_invokeSpecial.
785 * The resulting name will in an unresolved state.
786 */
787 public MemberName(Class<?> defClass, String name, MethodType type, byte refKind) {
788 int initFlags = CONSTRUCTOR_NAME.equals(name) ? IS_OBJECT_CONSTRUCTOR : IS_METHOD;
789 init(defClass, name, type, flagsMods(initFlags, 0, refKind));
790 initResolved(false);
791 }
792 /** Create a method, constructor, or field name from the given components:
793 * Reference kind, declaring class, name, type.
794 */
795 public MemberName(byte refKind, Class<?> defClass, String name, Object type) {
796 int kindFlags;
797 if (MethodHandleNatives.refKindIsField(refKind)) {
798 kindFlags = IS_FIELD;
799 if (!(type instanceof Class))
800 throw newIllegalArgumentException("not a field type");
801 } else if (MethodHandleNatives.refKindIsMethod(refKind)) {
802 kindFlags = IS_METHOD;
803 if (!(type instanceof MethodType))
804 throw newIllegalArgumentException("not a method type");
805 } else if (refKind == REF_newInvokeSpecial) {
806 kindFlags = IS_OBJECT_CONSTRUCTOR;
807 if (!(type instanceof MethodType) ||
808 !CONSTRUCTOR_NAME.equals(name))
809 throw newIllegalArgumentException("not a constructor type or name");
810 } else {
811 throw newIllegalArgumentException("bad reference kind "+refKind);
812 }
813 init(defClass, name, type, flagsMods(kindFlags, 0, refKind));
814 initResolved(false);
815 }
816
817 /** Query whether this member name is resolved.
818 * A resolved member name is one for which the JVM has found
819 * a method, constructor, field, or type binding corresponding exactly to the name.
820 * (Document?)
821 */
822 public boolean isResolved() {
823 return resolution == null;
824 }
825
826 void initResolved(boolean isResolved) {
827 assert(this.resolution == null); // not initialized yet!
828 if (!isResolved)
829 this.resolution = this;
830 assert(isResolved() == isResolved);
831 }
832
833 void checkForTypeAlias(Class<?> refc) {
834 if (isInvocable()) {
835 MethodType type;
836 if (this.type instanceof MethodType mt)
837 type = mt;
838 else
839 this.type = type = getMethodType();
840 if (type.erase() == type) return;
841 if (VerifyAccess.isTypeVisible(type, refc)) return;
842 throw new LinkageError("bad method type alias: "+type+" not visible from "+refc);
843 } else {
844 Class<?> type;
845 if (this.type instanceof Class<?> cl)
846 type = cl;
847 else
848 this.type = type = getFieldType();
849 if (VerifyAccess.isTypeVisible(type, refc)) return;
850 throw new LinkageError("bad field type alias: "+type+" not visible from "+refc);
851 }
852 }
853
854
855 /** Produce a string form of this member name.
856 * For types, it is simply the type's own string (as reported by {@code toString}).
857 * For fields, it is {@code "DeclaringClass.name/type"}.
858 * For methods and constructors, it is {@code "DeclaringClass.name(ptype...)rtype"}.
859 * If the declaring class is null, the prefix {@code "DeclaringClass."} is omitted.
860 * If the member is unresolved, a prefix {@code "*."} is prepended.
861 */
862 @SuppressWarnings("LocalVariableHidesMemberVariable")
863 @Override
864 public String toString() {
865 if (isType())
866 return type.toString(); // class java.lang.String
867 // else it is a field, method, or constructor
868 StringBuilder buf = new StringBuilder();
869 if (getDeclaringClass() != null) {
870 buf.append(getName(clazz));
871 buf.append('.');
872 }
873 String name = this.name; // avoid expanding from VM
874 buf.append(name == null ? "*" : name);
875 Object type = this.type; // avoid expanding from VM
876 if (!isInvocable()) {
877 buf.append('/');
878 buf.append(type == null ? "*" : getName(type));
879 } else {
880 buf.append(type == null ? "(*)*" : getName(type));
881 }
882 byte refKind = getReferenceKind();
883 if (refKind != REF_NONE) {
884 buf.append('/');
885 buf.append(MethodHandleNatives.refKindName(refKind));
886 }
887 //buf.append("#").append(System.identityHashCode(this));
888 return buf.toString();
889 }
890 private static String getName(Object obj) {
891 if (obj instanceof Class<?> cl)
892 return cl.getName();
893 return String.valueOf(obj);
894 }
895
896 public IllegalAccessException makeAccessException(String message, Object from) {
897 message = message + ": " + this;
898 if (from != null) {
899 if (from == MethodHandles.publicLookup()) {
900 message += ", from public Lookup";
901 } else {
902 Module m;
903 Class<?> plc;
904 if (from instanceof MethodHandles.Lookup lookup) {
905 from = lookup.lookupClass();
906 m = lookup.lookupClass().getModule();
907 plc = lookup.previousLookupClass();
908 } else {
909 m = ((Class<?>)from).getModule();
910 plc = null;
911 }
912 message += ", from " + from + " (" + m + ")";
913 if (plc != null) {
914 message += ", previous lookup " +
915 plc.getName() + " (" + plc.getModule() + ")";
916 }
917 }
918 }
919 return new IllegalAccessException(message);
920 }
921 private String message() {
922 if (isResolved())
923 return "no access";
924 else if (isObjectConstructor())
925 return "no such constructor";
926 else if (isMethod())
927 return "no such method";
928 else
929 return "no such field";
930 }
931 public ReflectiveOperationException makeAccessException() {
932 String message = message() + ": " + this;
933 ReflectiveOperationException ex;
934 if (isResolved() || !(resolution instanceof NoSuchMethodError ||
935 resolution instanceof NoSuchFieldError))
936 ex = new IllegalAccessException(message);
937 else if (isObjectConstructor())
938 ex = new NoSuchMethodException(message);
939 else if (isMethod())
940 ex = new NoSuchMethodException(message);
941 else
942 ex = new NoSuchFieldException(message);
943 if (resolution instanceof Throwable res)
944 ex.initCause(res);
945 return ex;
946 }
947
948 /** Actually making a query requires an access check. */
949 /*non-public*/
950 static Factory getFactory() {
951 return Factory.INSTANCE;
952 }
953 /** A factory type for resolving member names with the help of the VM.
954 * TBD: Define access-safe public constructors for this factory.
955 */
956 /*non-public*/
957 static class Factory {
958 private Factory() { } // singleton pattern
959 static final Factory INSTANCE = new Factory();
960
961 /** Produce a resolved version of the given member.
962 * Super types are searched (for inherited members) if {@code searchSupers} is true.
963 * Access checking is performed on behalf of the given {@code lookupClass}.
964 * If lookup fails or access is not permitted, null is returned.
965 * Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
966 */
967 private MemberName resolve(byte refKind, MemberName ref, Class<?> lookupClass, int allowedModes,
968 boolean speculativeResolve) {
969 MemberName m = ref.clone(); // JVM will side-effect the ref
970 assert(refKind == m.getReferenceKind());
971 try {
972 // There are 4 entities in play here:
973 // * LC: lookupClass
974 // * REFC: symbolic reference class (MN.clazz before resolution);
975 // * DEFC: resolved method holder (MN.clazz after resolution);
976 // * PTYPES: parameter types (MN.type)
977 //
978 // What we care about when resolving a MemberName is consistency between DEFC and PTYPES.
979 // We do type alias (TA) checks on DEFC to ensure that. DEFC is not known until the JVM
980 // finishes the resolution, so do TA checks right after MHN.resolve() is over.
981 //
982 // All parameters passed by a caller are checked against MH type (PTYPES) on every invocation,
983 // so it is safe to call a MH from any context.
984 //
985 // REFC view on PTYPES doesn't matter, since it is used only as a starting point for resolution and doesn't
986 // participate in method selection.
987 m = MethodHandleNatives.resolve(m, lookupClass, allowedModes, speculativeResolve);
988 if (m == null && speculativeResolve) {
989 return null;
990 }
991 m.checkForTypeAlias(m.getDeclaringClass());
992 m.resolution = null;
993 } catch (ClassNotFoundException | LinkageError ex) {
994 // JVM reports that the "bytecode behavior" would get an error
995 assert(!m.isResolved());
996 m.resolution = ex;
997 return m;
998 }
999 assert(m.referenceKindIsConsistent());
1000 m.initResolved(true);
1001 assert(m.vminfoIsConsistent());
1002 return m;
1003 }
1004 /** Produce a resolved version of the given member.
1005 * Super types are searched (for inherited members) if {@code searchSupers} is true.
1006 * Access checking is performed on behalf of the given {@code lookupClass}.
1007 * If lookup fails or access is not permitted, a {@linkplain ReflectiveOperationException} is thrown.
1008 * Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
1009 */
1010 public <NoSuchMemberException extends ReflectiveOperationException>
1011 MemberName resolveOrFail(byte refKind, MemberName m,
1012 Class<?> lookupClass, int allowedModes,
1013 Class<NoSuchMemberException> nsmClass)
1014 throws IllegalAccessException, NoSuchMemberException {
1015 assert lookupClass != null || allowedModes == LM_TRUSTED;
1016 MemberName result = resolve(refKind, m, lookupClass, allowedModes, false);
1017 if (result.isResolved())
1018 return result;
1019 ReflectiveOperationException ex = result.makeAccessException();
1020 if (ex instanceof IllegalAccessException iae) throw iae;
1021 throw nsmClass.cast(ex);
1022 }
1023 /** Produce a resolved version of the given member.
1024 * Super types are searched (for inherited members) if {@code searchSupers} is true.
1025 * Access checking is performed on behalf of the given {@code lookupClass}.
1026 * If lookup fails or access is not permitted, return null.
1027 * Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
1028 */
1029 public MemberName resolveOrNull(byte refKind, MemberName m, Class<?> lookupClass, int allowedModes) {
1030 assert lookupClass != null || allowedModes == LM_TRUSTED;
1031 MemberName result = resolve(refKind, m, lookupClass, allowedModes, true);
1032 if (result != null && result.isResolved())
1033 return result;
1034 return null;
1035 }
1036 }
1037 }