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.CheckedType;
29 import jdk.internal.value.NormalCheckedType;
30 import jdk.internal.value.NullRestrictedCheckedType;
31 import sun.invoke.util.VerifyAccess;
32
33 import java.lang.reflect.Constructor;
34 import java.lang.reflect.Field;
35 import java.lang.reflect.Member;
36 import java.lang.reflect.Method;
37 import java.lang.reflect.Modifier;
38 import java.util.Objects;
39
40 import static java.lang.invoke.MethodHandleNatives.Constants.*;
41 import static java.lang.invoke.MethodHandleStatics.newIllegalArgumentException;
42 import static java.lang.invoke.MethodHandleStatics.newInternalError;
43
44 /**
45 * A {@code MemberName} is a compact symbolic datum which fully characterizes
46 * a method or field reference.
47 * A member name refers to a field, method, constructor, or member type.
48 * Every member name has a simple name (a string) and a type (either a Class or MethodType).
49 * A member name may also have a non-null declaring class, or it may be simply
50 * a naked name/type pair.
51 * A member name may also have non-zero modifier flags.
52 * Finally, a member name may be either resolved or unresolved.
53 * If it is resolved, the existence of the named member has been determined by the JVM.
54 * <p>
55 * Whether resolved or not, a member name provides no access rights or
56 * invocation capability to its possessor. It is merely a compact
57 * representation of all symbolic information necessary to link to
58 * and properly use the named member.
59 * <p>
60 * When resolved, a member name's internal implementation may include references to JVM metadata.
61 * This representation is stateless and only descriptive.
62 * It provides no private information and no capability to use the member.
63 * <p>
64 * By contrast, a {@linkplain java.lang.reflect.Method} contains fuller information
65 * about the internals of a method (except its bytecodes) and also
66 * allows invocation. A MemberName is much lighter than a Method,
67 * since it contains about 7 fields to the 16 of Method (plus its sub-arrays),
68 * and those seven fields omit much of the information in Method.
69 * @author jrose
70 */
71
72 /*non-public*/
73 final class MemberName implements Member, Cloneable {
74 private Class<?> clazz; // class in which the member is defined
75 private String name; // may be null if not yet materialized
76 private Object type; // may be null if not yet materialized
77 private int flags; // modifier bits; see reflect.Modifier
78 private ResolvedMethodName method; // cached resolved method information
79 //@Injected intptr_t vmindex; // vtable index or offset of resolved member
80 Object resolution; // if null, this guy is resolved
81
82 /** Return the declaring class of this member.
83 * In the case of a bare name and type, the declaring class will be null.
84 */
85 public Class<?> getDeclaringClass() {
86 return clazz;
87 }
88
89 /** Utility method producing the class loader of the declaring class. */
90 public ClassLoader getClassLoader() {
91 return clazz.getClassLoader();
92 }
93
94 /** Return the simple name of this member.
95 * For a type, it is the same as {@link Class#getSimpleName}.
96 * For a method or field, it is the simple name of the member.
97 * For a constructor, it is always {@code "<init>"}.
98 */
99 public String getName() {
100 if (name == null) {
101 expandFromVM();
102 if (name == null) {
103 return null;
104 }
105 }
106 return name;
107 }
108
109 public MethodType getMethodOrFieldType() {
110 if (isInvocable())
111 return getMethodType();
112 if (isGetter())
113 return MethodType.methodType(getFieldType());
114 if (isSetter())
115 return MethodType.methodType(void.class, getFieldType());
116 throw new InternalError("not a method or field: "+this);
117 }
118
119 /** Return the declared type of this member, which
120 * must be a method or constructor.
121 */
122 public MethodType getMethodType() {
123 if (type == null) {
124 expandFromVM();
125 if (type == null) {
126 return null;
127 }
128 }
129 if (!isInvocable()) {
130 throw newIllegalArgumentException("not invocable, no method type");
131 }
132
133 {
134 // Get a snapshot of type which doesn't get changed by racing threads.
135 final Object type = this.type;
136 if (type instanceof MethodType mt) {
137 return mt;
138 }
139 }
140
141 // type is not a MethodType yet. Convert it thread-safely.
142 synchronized (this) {
143 if (type instanceof String sig) {
144 MethodType res = MethodType.fromDescriptor(sig, getClassLoader());
145 type = res;
146 } else if (type instanceof Object[] typeInfo) {
147 Class<?>[] ptypes = (Class<?>[]) typeInfo[1];
148 Class<?> rtype = (Class<?>) typeInfo[0];
149 MethodType res = MethodType.methodType(rtype, ptypes, true);
150 type = res;
151 }
152 // Make sure type is a MethodType for racing threads.
153 assert type instanceof MethodType : "bad method type " + type;
154 }
155 return (MethodType) type;
156 }
157
158 /** Return the descriptor of this member, which
159 * must be a method or constructor.
160 */
161 String getMethodDescriptor() {
162 if (type == null) {
163 expandFromVM();
164 if (type == null) {
165 return null;
166 }
167 }
168 if (!isInvocable()) {
169 throw newIllegalArgumentException("not invocable, no method type");
170 }
171
172 // Get a snapshot of type which doesn't get changed by racing threads.
173 final Object type = this.type;
174 if (type instanceof String str) {
175 return str;
176 } else {
177 return getMethodType().toMethodDescriptorString();
178 }
179 }
180
181 /** Return the actual type under which this method or constructor must be invoked.
182 * For non-static methods or constructors, this is the type with a leading parameter,
183 * a reference to declaring class. For static methods, it is the same as the declared type.
184 */
185 public MethodType getInvocationType() {
186 MethodType itype = getMethodOrFieldType();
187 if (isConstructor() && getReferenceKind() == REF_newInvokeSpecial)
188 return itype.changeReturnType(clazz);
189 if (!isStatic())
190 return itype.insertParameterTypes(0, clazz);
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 /**
231 * Return {@code CheckedType} representing the type of this member.
232 */
233 public CheckedType getCheckedFieldType() {
234 return isNullRestricted() ? NullRestrictedCheckedType.of(getFieldType())
235 : NormalCheckedType.of(getFieldType());
236 }
237
238 /** Utility method to produce either the method type or field type of this member. */
239 public Object getType() {
240 return (isInvocable() ? getMethodType() : getFieldType());
241 }
242
243 /** Return the modifier flags of this member.
244 * @see java.lang.reflect.Modifier
245 */
246 public int getModifiers() {
247 return (flags & RECOGNIZED_MODIFIERS);
248 }
249
250 /** Return the reference kind of this member, or zero if none.
251 */
252 public byte getReferenceKind() {
253 return (byte) ((flags >>> MN_REFERENCE_KIND_SHIFT) & MN_REFERENCE_KIND_MASK);
254 }
255 private boolean referenceKindIsConsistent() {
256 byte refKind = getReferenceKind();
257 if (refKind == REF_NONE) return isType();
258 if (isField()) {
259 assert(staticIsConsistent());
260 assert(MethodHandleNatives.refKindIsField(refKind));
261 } else if (isConstructor()) {
262 assert(refKind == REF_newInvokeSpecial || refKind == REF_invokeSpecial);
263 } else if (isMethod()) {
264 assert(staticIsConsistent());
265 assert(MethodHandleNatives.refKindIsMethod(refKind));
266 if (clazz.isInterface())
267 assert(refKind == REF_invokeInterface ||
268 refKind == REF_invokeStatic ||
269 refKind == REF_invokeSpecial ||
270 refKind == REF_invokeVirtual && isObjectPublicMethod());
271 } else {
272 assert(false);
273 }
274 return true;
275 }
276 private boolean isObjectPublicMethod() {
277 if (clazz == Object.class) return true;
278 MethodType mtype = getMethodType();
279 if (name.equals("toString") && mtype.returnType() == String.class && mtype.parameterCount() == 0)
280 return true;
281 if (name.equals("hashCode") && mtype.returnType() == int.class && mtype.parameterCount() == 0)
282 return true;
283 if (name.equals("equals") && mtype.returnType() == boolean.class && mtype.parameterCount() == 1 && mtype.parameterType(0) == Object.class)
284 return true;
285 return false;
286 }
287
288 /*non-public*/
289 boolean referenceKindIsConsistentWith(int originalRefKind) {
290 int refKind = getReferenceKind();
291 if (refKind == originalRefKind) return true;
292 if (getClass().desiredAssertionStatus()) {
293 switch (originalRefKind) {
294 case REF_invokeInterface -> {
295 // Looking up an interface method, can get (e.g.) Object.hashCode
296 assert (refKind == REF_invokeVirtual || refKind == REF_invokeSpecial) : this;
297 }
298 case REF_invokeVirtual, REF_newInvokeSpecial -> {
299 // Looked up a virtual, can get (e.g.) final String.hashCode.
300 assert (refKind == REF_invokeSpecial) : this;
301 }
302 default -> {
303 assert (false) : this + " != " + MethodHandleNatives.refKindName((byte) originalRefKind);
304 }
305 }
306 }
307 return true;
308 }
309 private boolean staticIsConsistent() {
310 byte refKind = getReferenceKind();
311 return MethodHandleNatives.refKindIsStatic(refKind) == isStatic() || getModifiers() == 0;
312 }
313 private boolean vminfoIsConsistent() {
314 byte refKind = getReferenceKind();
315 assert(isResolved()); // else don't call
316 Object vminfo = MethodHandleNatives.getMemberVMInfo(this);
317 assert(vminfo instanceof Object[]);
318 long vmindex = (Long) ((Object[])vminfo)[0];
319 Object vmtarget = ((Object[])vminfo)[1];
320 if (MethodHandleNatives.refKindIsField(refKind)) {
321 assert(vmindex >= 0) : vmindex + ":" + this;
322 assert(vmtarget instanceof Class);
323 } else {
324 if (MethodHandleNatives.refKindDoesDispatch(refKind))
325 assert(vmindex >= 0) : vmindex + ":" + this;
326 else
327 assert(vmindex < 0) : vmindex;
328 assert(vmtarget instanceof MemberName) : vmtarget + " in " + this;
329 }
330 return true;
331 }
332
333 private MemberName changeReferenceKind(byte refKind, byte oldKind) {
334 assert(getReferenceKind() == oldKind && MethodHandleNatives.refKindIsValid(refKind));
335 flags += (((int)refKind - oldKind) << MN_REFERENCE_KIND_SHIFT);
336 return this;
337 }
338
339 private boolean matchingFlagsSet(int mask, int flags) {
340 return (this.flags & mask) == flags;
341 }
342 private boolean allFlagsSet(int flags) {
343 return (this.flags & flags) == flags;
344 }
345 private boolean anyFlagSet(int flags) {
346 return (this.flags & flags) != 0;
347 }
348
349 /** Utility method to query if this member is a method handle invocation (invoke or invokeExact).
350 */
351 public boolean isMethodHandleInvoke() {
352 final int bits = MH_INVOKE_MODS &~ Modifier.PUBLIC;
353 final int negs = Modifier.STATIC;
354 if (matchingFlagsSet(bits | negs, bits) && clazz == MethodHandle.class) {
355 return isMethodHandleInvokeName(name);
356 }
357 return false;
358 }
359 public static boolean isMethodHandleInvokeName(String name) {
360 return switch (name) {
361 case "invoke", "invokeExact" -> true;
362 default -> false;
363 };
364 }
365 public boolean isVarHandleMethodInvoke() {
366 final int bits = MH_INVOKE_MODS &~ Modifier.PUBLIC;
367 final int negs = Modifier.STATIC;
368 if (matchingFlagsSet(bits | negs, bits) && clazz == VarHandle.class) {
369 return isVarHandleMethodInvokeName(name);
370 }
371 return false;
372 }
373 public static boolean isVarHandleMethodInvokeName(String name) {
374 try {
375 VarHandle.AccessMode.valueFromMethodName(name);
376 return true;
377 } catch (IllegalArgumentException e) {
378 return false;
379 }
380 }
381 private static final int MH_INVOKE_MODS = Modifier.NATIVE | Modifier.FINAL | Modifier.PUBLIC;
382
383 /** Utility method to query the modifier flags of this member. */
384 public boolean isStatic() {
385 return Modifier.isStatic(flags);
386 }
387 /** Utility method to query the modifier flags of this member. */
388 public boolean isPublic() {
389 return Modifier.isPublic(flags);
390 }
391 /** Utility method to query the modifier flags of this member. */
392 public boolean isPrivate() {
393 return Modifier.isPrivate(flags);
394 }
395 /** Utility method to query the modifier flags of this member. */
396 public boolean isProtected() {
397 return Modifier.isProtected(flags);
398 }
399 /** Utility method to query the modifier flags of this member. */
400 public boolean isFinal() {
401 return Modifier.isFinal(flags);
402 }
403 /** Utility method to query whether this member or its defining class is final. */
404 public boolean canBeStaticallyBound() {
405 return Modifier.isFinal(flags | clazz.getModifiers());
406 }
407 /** Utility method to query the modifier flags of this member. */
408 public boolean isVolatile() {
409 return Modifier.isVolatile(flags);
410 }
411 /** Utility method to query the modifier flags of this member. */
412 public boolean isAbstract() {
413 return Modifier.isAbstract(flags);
414 }
415 /** Utility method to query the modifier flags of this member. */
416 public boolean isNative() {
417 return Modifier.isNative(flags);
418 }
419 // let the rest (native, volatile, transient, etc.) be tested via Modifier.isFoo
420
421 // unofficial modifier flags, used by HotSpot:
422 static final int BRIDGE = 0x00000040;
423 static final int VARARGS = 0x00000080;
424 static final int SYNTHETIC = 0x00001000;
425 static final int ANNOTATION = 0x00002000;
426 static final int ENUM = 0x00004000;
427
428 /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
429 public boolean isBridge() {
430 return allFlagsSet(IS_METHOD | BRIDGE);
431 }
432 /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
433 public boolean isVarargs() {
434 return allFlagsSet(VARARGS) && isInvocable();
435 }
436 /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
437 public boolean isSynthetic() {
438 return allFlagsSet(SYNTHETIC);
439 }
440
441 /** Query whether this member is a flat field */
442 public boolean isFlat() { return (flags & MN_FLAT_FIELD) == MN_FLAT_FIELD; }
443
444 /** Query whether this member is a null-restricted field */
445 public boolean isNullRestricted() { return (flags & MN_NULL_RESTRICTED) == MN_NULL_RESTRICTED; }
446
447 static final String CONSTRUCTOR_NAME = "<init>";
448
449 // modifiers exported by the JVM:
450 static final int RECOGNIZED_MODIFIERS = 0xFFFF;
451
452 // private flags, not part of RECOGNIZED_MODIFIERS:
453 static final int
454 IS_METHOD = MN_IS_METHOD, // method (not constructor)
455 IS_CONSTRUCTOR = MN_IS_CONSTRUCTOR, // constructor
456 IS_FIELD = MN_IS_FIELD, // field
457 IS_TYPE = MN_IS_TYPE, // nested type
458 CALLER_SENSITIVE = MN_CALLER_SENSITIVE, // @CallerSensitive annotation detected
459 TRUSTED_FINAL = MN_TRUSTED_FINAL; // trusted final field
460
461 static final int ALL_ACCESS = Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED;
462 static final int ALL_KINDS = IS_METHOD | IS_CONSTRUCTOR | IS_FIELD | IS_TYPE;
463 static final int IS_INVOCABLE = IS_METHOD | IS_CONSTRUCTOR;
464
465 /** Utility method to query whether this member is a method or constructor. */
466 public boolean isInvocable() {
467 return anyFlagSet(IS_INVOCABLE);
468 }
469 /** Query whether this member is a method. */
470 public boolean isMethod() {
471 return allFlagsSet(IS_METHOD);
472 }
473 /** Query whether this member is a constructor. */
474 public boolean isConstructor() {
475 return allFlagsSet(IS_CONSTRUCTOR);
476 }
477 /** Query whether this member is a field. */
478 public boolean isField() {
479 return allFlagsSet(IS_FIELD);
480 }
481 /** Query whether this member is a type. */
482 public boolean isType() {
483 return allFlagsSet(IS_TYPE);
484 }
485 /** Utility method to query whether this member is neither public, private, nor protected. */
486 public boolean isPackage() {
487 return !anyFlagSet(ALL_ACCESS);
488 }
489 /** Query whether this member has a CallerSensitive annotation. */
490 public boolean isCallerSensitive() {
491 return allFlagsSet(CALLER_SENSITIVE);
492 }
493 /** Query whether this member is a trusted final field. */
494 public boolean isTrustedFinalField() {
495 return allFlagsSet(TRUSTED_FINAL | IS_FIELD);
496 }
497
498 /**
499 * Check if MemberName is a call to a method named {@code name} in class {@code declaredClass}.
500 */
501 public boolean refersTo(Class<?> declc, String n) {
502 return clazz == declc && getName().equals(n);
503 }
504
505 /** Initialize a query. It is not resolved. */
506 private void init(Class<?> defClass, String name, Object type, int flags) {
507 // defining class is allowed to be null (for a naked name/type pair)
508 //name.toString(); // null check
509 //type.equals(type); // null check
510 // fill in fields:
511 this.clazz = defClass;
512 this.name = name;
513 this.type = type;
514 this.flags = flags;
515 assert(anyFlagSet(ALL_KINDS) && this.resolution == null); // nobody should have touched this yet
516 //assert(referenceKindIsConsistent()); // do this after resolution
517 }
518
519 /**
520 * Calls down to the VM to fill in the fields. This method is
521 * synchronized to avoid racing calls.
522 */
523 private void expandFromVM() {
524 if (type != null) {
525 return;
526 }
527 if (!isResolved()) {
528 return;
529 }
530 MethodHandleNatives.expand(this);
531 }
532
533 // Capturing information from the Core Reflection API:
534 private static int flagsMods(int flags, int mods, byte refKind) {
535 assert((flags & RECOGNIZED_MODIFIERS) == 0
536 && (mods & ~RECOGNIZED_MODIFIERS) == 0
537 && (refKind & ~MN_REFERENCE_KIND_MASK) == 0);
538 return flags | mods | (refKind << MN_REFERENCE_KIND_SHIFT);
539 }
540 /** Create a name for the given reflected method. The resulting name will be in a resolved state. */
541 public MemberName(Method m) {
542 this(m, false);
543 }
544 @SuppressWarnings("LeakingThisInConstructor")
545 public MemberName(Method m, boolean wantSpecial) {
546 Objects.requireNonNull(m);
547 // fill in vmtarget, vmindex while we have m in hand:
548 MethodHandleNatives.init(this, m);
549 if (clazz == null) { // MHN.init failed
550 if (m.getDeclaringClass() == MethodHandle.class &&
551 isMethodHandleInvokeName(m.getName())) {
552 // The JVM did not reify this signature-polymorphic instance.
553 // Need a special case here.
554 // See comments on MethodHandleNatives.linkMethod.
555 MethodType type = MethodType.methodType(m.getReturnType(), m.getParameterTypes());
556 int flags = flagsMods(IS_METHOD, m.getModifiers(), REF_invokeVirtual);
557 init(MethodHandle.class, m.getName(), type, flags);
558 if (isMethodHandleInvoke())
559 return;
560 }
561 if (m.getDeclaringClass() == VarHandle.class &&
562 isVarHandleMethodInvokeName(m.getName())) {
563 // The JVM did not reify this signature-polymorphic instance.
564 // Need a special case here.
565 // See comments on MethodHandleNatives.linkMethod.
566 MethodType type = MethodType.methodType(m.getReturnType(), m.getParameterTypes());
567 int flags = flagsMods(IS_METHOD, m.getModifiers(), REF_invokeVirtual);
568 init(VarHandle.class, m.getName(), type, flags);
569 if (isVarHandleMethodInvoke())
570 return;
571 }
572 throw new LinkageError(m.toString());
573 }
574 assert(isResolved());
575 this.name = m.getName();
576 if (this.type == null)
577 this.type = new Object[] { m.getReturnType(), m.getParameterTypes() };
578 if (wantSpecial) {
579 if (isAbstract())
580 throw new AbstractMethodError(this.toString());
581 if (getReferenceKind() == REF_invokeVirtual)
582 changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual);
583 else if (getReferenceKind() == REF_invokeInterface)
584 // invokeSpecial on a default method
585 changeReferenceKind(REF_invokeSpecial, REF_invokeInterface);
586 }
587 }
588 public MemberName asSpecial() {
589 switch (getReferenceKind()) {
590 case REF_invokeSpecial: return this;
591 case REF_invokeVirtual: return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual);
592 case REF_invokeInterface: return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeInterface);
593 case REF_newInvokeSpecial: return clone().changeReferenceKind(REF_invokeSpecial, REF_newInvokeSpecial);
594 }
595 throw new IllegalArgumentException(this.toString());
596 }
597 /** If this MN is not REF_newInvokeSpecial, return a clone with that ref. kind.
598 * In that case it must already be REF_invokeSpecial.
599 */
600 public MemberName asConstructor() {
601 switch (getReferenceKind()) {
602 case REF_invokeSpecial: return clone().changeReferenceKind(REF_newInvokeSpecial, REF_invokeSpecial);
603 case REF_newInvokeSpecial: return this;
604 }
605 throw new IllegalArgumentException(this.toString());
606 }
607 /** If this MN is a REF_invokeSpecial, return a clone with the "normal" kind
608 * REF_invokeVirtual; also switch either to REF_invokeInterface if clazz.isInterface.
609 * The end result is to get a fully virtualized version of the MN.
610 * (Note that resolving in the JVM will sometimes devirtualize, changing
611 * REF_invokeVirtual of a final to REF_invokeSpecial, and REF_invokeInterface
612 * in some corner cases to either of the previous two; this transform
613 * undoes that change under the assumption that it occurred.)
614 */
615 public MemberName asNormalOriginal() {
616 byte refKind = getReferenceKind();
617 byte newRefKind = switch (refKind) {
618 case REF_invokeInterface,
619 REF_invokeVirtual,
620 REF_invokeSpecial -> clazz.isInterface() ? REF_invokeInterface : REF_invokeVirtual;
621 default -> refKind;
622 };
623 if (newRefKind == refKind)
624 return this;
625 MemberName result = clone().changeReferenceKind(newRefKind, refKind);
626 assert(this.referenceKindIsConsistentWith(result.getReferenceKind()));
627 return result;
628 }
629 /** Create a name for the given reflected constructor. The resulting name will be in a resolved state. */
630 @SuppressWarnings("LeakingThisInConstructor")
631 public MemberName(Constructor<?> ctor) {
632 Objects.requireNonNull(ctor);
633 // fill in vmtarget, vmindex while we have ctor in hand:
634 MethodHandleNatives.init(this, ctor);
635 assert(isResolved() && this.clazz != null);
636 this.name = CONSTRUCTOR_NAME;
637 if (this.type == null)
638 this.type = new Object[] { void.class, ctor.getParameterTypes() };
639 }
640 /** Create a name for the given reflected field. The resulting name will be in a resolved state.
641 */
642 public MemberName(Field fld) {
643 this(fld, false);
644 }
645 static {
646 // the following MemberName constructor relies on these ranges matching up
647 assert((REF_putStatic - REF_getStatic) == (REF_putField - REF_getField));
648 }
649 @SuppressWarnings("LeakingThisInConstructor")
650 public MemberName(Field fld, boolean makeSetter) {
651 Objects.requireNonNull(fld);
652 // fill in vmtarget, vmindex while we have fld in hand:
653 MethodHandleNatives.init(this, fld);
654 assert(isResolved() && this.clazz != null);
655 this.name = fld.getName();
656 this.type = fld.getType();
657 byte refKind = this.getReferenceKind();
658 assert(refKind == (isStatic() ? REF_getStatic : REF_getField));
659 if (makeSetter) {
660 changeReferenceKind((byte)(refKind + (REF_putStatic - REF_getStatic)), refKind);
661 }
662 }
663 public boolean isGetter() {
664 return MethodHandleNatives.refKindIsGetter(getReferenceKind());
665 }
666 public boolean isSetter() {
667 return MethodHandleNatives.refKindIsSetter(getReferenceKind());
668 }
669
670 /** Create a name for the given class. The resulting name will be in a resolved state. */
671 public MemberName(Class<?> type) {
672 init(type.getDeclaringClass(), type.getSimpleName(), type,
673 flagsMods(IS_TYPE, type.getModifiers(), REF_NONE));
674 initResolved(true);
675 }
676
677 /**
678 * Create a name for a signature-polymorphic invoker.
679 * This is a placeholder for a signature-polymorphic instance
680 * (of MH.invokeExact, etc.) that the JVM does not reify.
681 * See comments on {@link MethodHandleNatives#linkMethod}.
682 */
683 static MemberName makeMethodHandleInvoke(String name, MethodType type) {
684 return makeMethodHandleInvoke(name, type, MH_INVOKE_MODS | SYNTHETIC);
685 }
686 static MemberName makeMethodHandleInvoke(String name, MethodType type, int mods) {
687 MemberName mem = new MemberName(MethodHandle.class, name, type, REF_invokeVirtual);
688 mem.flags |= mods; // it's not resolved, but add these modifiers anyway
689 assert(mem.isMethodHandleInvoke()) : mem;
690 return mem;
691 }
692
693 static MemberName makeVarHandleMethodInvoke(String name, MethodType type) {
694 return makeVarHandleMethodInvoke(name, type, MH_INVOKE_MODS | SYNTHETIC);
695 }
696 static MemberName makeVarHandleMethodInvoke(String name, MethodType type, int mods) {
697 MemberName mem = new MemberName(VarHandle.class, name, type, REF_invokeVirtual);
698 mem.flags |= mods; // it's not resolved, but add these modifiers anyway
699 assert(mem.isVarHandleMethodInvoke()) : mem;
700 return mem;
701 }
702
703 // bare-bones constructor; the JVM will fill it in
704 MemberName() { }
705
706 // locally useful cloner
707 @Override protected MemberName clone() {
708 try {
709 return (MemberName) super.clone();
710 } catch (CloneNotSupportedException ex) {
711 throw newInternalError(ex);
712 }
713 }
714
715 /** Get the definition of this member name.
716 * This may be in a super-class of the declaring class of this member.
717 */
718 public MemberName getDefinition() {
719 if (!isResolved()) throw new IllegalStateException("must be resolved: "+this);
720 if (isType()) return this;
721 MemberName res = this.clone();
722 res.clazz = null;
723 res.type = null;
724 res.name = null;
725 res.resolution = res;
726 res.expandFromVM();
727 assert(res.getName().equals(this.getName()));
728 return res;
729 }
730
731 @Override
732 @SuppressWarnings({"deprecation", "removal"})
733 public int hashCode() {
734 // Avoid autoboxing getReferenceKind(), since this is used early and will force
735 // early initialization of Byte$ByteCache
736 return Objects.hash(clazz, new Byte(getReferenceKind()), name, getType());
737 }
738
739 @Override
740 public boolean equals(Object that) {
741 return that instanceof MemberName mn && this.equals(mn);
742 }
743
744 /** Decide if two member names have exactly the same symbolic content.
745 * Does not take into account any actual class members, so even if
746 * two member names resolve to the same actual member, they may
747 * be distinct references.
748 */
749 public boolean equals(MemberName that) {
750 if (this == that) return true;
751 if (that == null) return false;
752 return this.clazz == that.clazz
753 && this.getReferenceKind() == that.getReferenceKind()
754 && Objects.equals(this.name, that.name)
755 && Objects.equals(this.getType(), that.getType());
756 }
757
758 // Construction from symbolic parts, for queries:
759 /** Create a field or type name from the given components:
760 * Declaring class, name, type, reference kind.
761 * The declaring class may be supplied as null if this is to be a bare name and type.
762 * The resulting name will in an unresolved state.
763 */
764 public MemberName(Class<?> defClass, String name, Class<?> type, byte refKind) {
765 init(defClass, name, type, flagsMods(IS_FIELD, 0, refKind));
766 initResolved(false);
767 }
768 /** Create a method or constructor name from the given components:
769 * Declaring class, name, type, reference kind.
770 * It will be a constructor if and only if the name is {@code "<init>"}.
771 * The declaring class may be supplied as null if this is to be a bare name and type.
772 * The last argument is optional, a boolean which requests REF_invokeSpecial.
773 * The resulting name will in an unresolved state.
774 */
775 public MemberName(Class<?> defClass, String name, MethodType type, byte refKind) {
776 int initFlags = CONSTRUCTOR_NAME.equals(name) ? IS_CONSTRUCTOR : IS_METHOD;
777 init(defClass, name, type, flagsMods(initFlags, 0, refKind));
778 initResolved(false);
779 }
780 /** Create a method, constructor, or field name from the given components:
781 * Reference kind, declaring class, name, type.
782 */
783 public MemberName(byte refKind, Class<?> defClass, String name, Object type) {
784 int kindFlags;
785 if (MethodHandleNatives.refKindIsField(refKind)) {
786 kindFlags = IS_FIELD;
787 if (!(type instanceof Class))
788 throw newIllegalArgumentException("not a field type");
789 } else if (MethodHandleNatives.refKindIsMethod(refKind)) {
790 kindFlags = IS_METHOD;
791 if (!(type instanceof MethodType))
792 throw newIllegalArgumentException("not a method type");
793 } else if (refKind == REF_newInvokeSpecial) {
794 kindFlags = IS_CONSTRUCTOR;
795 if (!(type instanceof MethodType) ||
796 !CONSTRUCTOR_NAME.equals(name))
797 throw newIllegalArgumentException("not a constructor type or name");
798 } else {
799 throw newIllegalArgumentException("bad reference kind "+refKind);
800 }
801 init(defClass, name, type, flagsMods(kindFlags, 0, refKind));
802 initResolved(false);
803 }
804
805 /** Query whether this member name is resolved.
806 * A resolved member name is one for which the JVM has found
807 * a method, constructor, field, or type binding corresponding exactly to the name.
808 * (Document?)
809 */
810 public boolean isResolved() {
811 return resolution == null;
812 }
813
814 void initResolved(boolean isResolved) {
815 assert(this.resolution == null); // not initialized yet!
816 if (!isResolved)
817 this.resolution = this;
818 assert(isResolved() == isResolved);
819 }
820
821 void ensureTypeVisible(Class<?> refc) {
822 if (isInvocable()) {
823 MethodType type;
824 if (this.type instanceof MethodType mt)
825 type = mt;
826 else
827 this.type = type = getMethodType();
828 if (type.erase() == type) return;
829 if (VerifyAccess.ensureTypeVisible(type, refc)) return;
830 throw new LinkageError("bad method type alias: "+type+" not visible from "+refc);
831 } else {
832 Class<?> type;
833 if (this.type instanceof Class<?> cl)
834 type = cl;
835 else
836 this.type = type = getFieldType();
837 if (VerifyAccess.ensureTypeVisible(type, refc)) return;
838 throw new LinkageError("bad field type alias: "+type+" not visible from "+refc);
839 }
840 }
841
842
843 /** Produce a string form of this member name.
844 * For types, it is simply the type's own string (as reported by {@code toString}).
845 * For fields, it is {@code "DeclaringClass.name/type"}.
846 * For methods and constructors, it is {@code "DeclaringClass.name(ptype...)rtype"}.
847 * If the declaring class is null, the prefix {@code "DeclaringClass."} is omitted.
848 * If the member is unresolved, a prefix {@code "*."} is prepended.
849 */
850 @SuppressWarnings("LocalVariableHidesMemberVariable")
851 @Override
852 public String toString() {
853 if (isType())
854 return type.toString(); // class java.lang.String
855 // else it is a field, method, or constructor
856 StringBuilder buf = new StringBuilder();
857 if (getDeclaringClass() != null) {
858 buf.append(getName(clazz));
859 buf.append('.');
860 }
861 String name = this.name; // avoid expanding from VM
862 buf.append(name == null ? "*" : name);
863 Object type = this.type; // avoid expanding from VM
864 if (!isInvocable()) {
865 buf.append('/');
866 buf.append(type == null ? "*" : getName(type));
867 } else {
868 buf.append(type == null ? "(*)*" : getName(type));
869 }
870 byte refKind = getReferenceKind();
871 if (refKind != REF_NONE) {
872 buf.append('/');
873 buf.append(MethodHandleNatives.refKindName(refKind));
874 }
875 //buf.append("#").append(System.identityHashCode(this));
876 return buf.toString();
877 }
878 private static String getName(Object obj) {
879 if (obj instanceof Class<?> cl)
880 return cl.getName();
881 return String.valueOf(obj);
882 }
883
884 public IllegalAccessException makeAccessException(String message, Object from) {
885 message = message + ": " + this;
886 if (from != null) {
887 if (from == MethodHandles.publicLookup()) {
888 message += ", from public Lookup";
889 } else {
890 Module m;
891 Class<?> plc;
892 if (from instanceof MethodHandles.Lookup lookup) {
893 from = lookup.lookupClass();
894 m = lookup.lookupClass().getModule();
895 plc = lookup.previousLookupClass();
896 } else {
897 m = ((Class<?>)from).getModule();
898 plc = null;
899 }
900 message += ", from " + from + " (" + m + ")";
901 if (plc != null) {
902 message += ", previous lookup " +
903 plc.getName() + " (" + plc.getModule() + ")";
904 }
905 }
906 }
907 return new IllegalAccessException(message);
908 }
909 private String message() {
910 if (isResolved())
911 return "no access";
912 else if (isConstructor())
913 return "no such constructor";
914 else if (isMethod())
915 return "no such method";
916 else
917 return "no such field";
918 }
919 public ReflectiveOperationException makeAccessException() {
920 String message = message() + ": " + this;
921 ReflectiveOperationException ex;
922 if (isResolved() || !(resolution instanceof NoSuchMethodError ||
923 resolution instanceof NoSuchFieldError))
924 ex = new IllegalAccessException(message);
925 else if (isConstructor())
926 ex = new NoSuchMethodException(message);
927 else if (isMethod())
928 ex = new NoSuchMethodException(message);
929 else
930 ex = new NoSuchFieldException(message);
931 if (resolution instanceof Throwable res)
932 ex.initCause(res);
933 return ex;
934 }
935
936 /** Actually making a query requires an access check. */
937 /*non-public*/
938 static Factory getFactory() {
939 return Factory.INSTANCE;
940 }
941 /** A factory type for resolving member names with the help of the VM.
942 * TBD: Define access-safe public constructors for this factory.
943 */
944 /*non-public*/
945 static class Factory {
946 private Factory() { } // singleton pattern
947 static final Factory INSTANCE = new Factory();
948
949 /** Produce a resolved version of the given member.
950 * Super types are searched (for inherited members) if {@code searchSupers} is true.
951 * Access checking is performed on behalf of the given {@code lookupClass}.
952 * If lookup fails or access is not permitted, null is returned.
953 * Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
954 */
955 private MemberName resolve(byte refKind, MemberName ref, Class<?> lookupClass, int allowedModes,
956 boolean speculativeResolve) {
957 MemberName m = ref.clone(); // JVM will side-effect the ref
958 assert(refKind == m.getReferenceKind());
959 try {
960 // There are 4 entities in play here:
961 // * LC: lookupClass
962 // * REFC: symbolic reference class (MN.clazz before resolution);
963 // * DEFC: resolved method holder (MN.clazz after resolution);
964 // * PTYPES: parameter types (MN.type)
965 //
966 // What we care about when resolving a MemberName is consistency between DEFC and PTYPES.
967 // We do type alias (TA) checks on DEFC to ensure that. DEFC is not known until the JVM
968 // finishes the resolution, so do TA checks right after MHN.resolve() is over.
969 //
970 // All parameters passed by a caller are checked against MH type (PTYPES) on every invocation,
971 // so it is safe to call a MH from any context.
972 //
973 // REFC view on PTYPES doesn't matter, since it is used only as a starting point for resolution and doesn't
974 // participate in method selection.
975 m = MethodHandleNatives.resolve(m, lookupClass, allowedModes, speculativeResolve);
976 if (m == null && speculativeResolve) {
977 return null;
978 }
979 m.ensureTypeVisible(m.getDeclaringClass());
980 m.resolution = null;
981 } catch (ClassNotFoundException | LinkageError ex) {
982 // JVM reports that the "bytecode behavior" would get an error
983 assert(!m.isResolved());
984 m.resolution = ex;
985 return m;
986 }
987 assert(m.referenceKindIsConsistent());
988 m.initResolved(true);
989 assert(m.vminfoIsConsistent());
990 return m;
991 }
992 /** Produce a resolved version of the given member.
993 * Super types are searched (for inherited members) if {@code searchSupers} is true.
994 * Access checking is performed on behalf of the given {@code lookupClass}.
995 * If lookup fails or access is not permitted, a {@linkplain ReflectiveOperationException} is thrown.
996 * Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
997 */
998 public <NoSuchMemberException extends ReflectiveOperationException>
999 MemberName resolveOrFail(byte refKind, MemberName m,
1000 Class<?> lookupClass, int allowedModes,
1001 Class<NoSuchMemberException> nsmClass)
1002 throws IllegalAccessException, NoSuchMemberException {
1003 assert lookupClass != null || allowedModes == LM_TRUSTED;
1004 MemberName result = resolve(refKind, m, lookupClass, allowedModes, false);
1005 if (result.isResolved())
1006 return result;
1007 ReflectiveOperationException ex = result.makeAccessException();
1008 if (ex instanceof IllegalAccessException iae) throw iae;
1009 throw nsmClass.cast(ex);
1010 }
1011 /** Produce a resolved version of the given member.
1012 * Super types are searched (for inherited members) if {@code searchSupers} is true.
1013 * Access checking is performed on behalf of the given {@code lookupClass}.
1014 * If lookup fails or access is not permitted, return null.
1015 * Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
1016 */
1017 public MemberName resolveOrNull(byte refKind, MemberName m, Class<?> lookupClass, int allowedModes) {
1018 assert lookupClass != null || allowedModes == LM_TRUSTED;
1019 MemberName result = resolve(refKind, m, lookupClass, allowedModes, true);
1020 if (result != null && result.isResolved())
1021 return result;
1022 return null;
1023 }
1024 }
1025 }