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 // all fields declared in a value type are effectively final
402 assert(!clazz.isValue() || !isField() || Modifier.isFinal(flags));
403 return Modifier.isFinal(flags);
404 }
405 /** Utility method to query whether this member or its defining class is final. */
406 public boolean canBeStaticallyBound() {
407 return Modifier.isFinal(flags | clazz.getModifiers());
408 }
409 /** Utility method to query the modifier flags of this member. */
410 public boolean isVolatile() {
411 return Modifier.isVolatile(flags);
412 }
413 /** Utility method to query the modifier flags of this member. */
414 public boolean isAbstract() {
415 return Modifier.isAbstract(flags);
416 }
417 /** Utility method to query the modifier flags of this member. */
418 public boolean isNative() {
419 return Modifier.isNative(flags);
420 }
421 // let the rest (native, volatile, transient, etc.) be tested via Modifier.isFoo
422
423 // unofficial modifier flags, used by HotSpot:
424 static final int BRIDGE = 0x00000040;
425 static final int VARARGS = 0x00000080;
426 static final int SYNTHETIC = 0x00001000;
427 static final int ANNOTATION = 0x00002000;
428 static final int ENUM = 0x00004000;
429
430 /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
431 public boolean isBridge() {
432 return allFlagsSet(IS_METHOD | BRIDGE);
433 }
434 /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
435 public boolean isVarargs() {
436 return allFlagsSet(VARARGS) && isInvocable();
437 }
438 /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
439 public boolean isSynthetic() {
440 return allFlagsSet(SYNTHETIC);
441 }
442
443 /** Query whether this member is a flattened field */
444 public boolean isFlat() { return (flags & MN_FLAT_FIELD) == MN_FLAT_FIELD; }
445
446 /** Query whether this member is a null-restricted field */
447 public boolean isNullRestricted() { return (flags & MN_NULL_RESTRICTED) == MN_NULL_RESTRICTED; }
448
449 static final String CONSTRUCTOR_NAME = "<init>";
450
451 // modifiers exported by the JVM:
452 static final int RECOGNIZED_MODIFIERS = 0xFFFF;
453
454 // private flags, not part of RECOGNIZED_MODIFIERS:
455 static final int
456 IS_METHOD = MN_IS_METHOD, // method (not constructor)
457 IS_CONSTRUCTOR = MN_IS_CONSTRUCTOR, // constructor
458 IS_FIELD = MN_IS_FIELD, // field
459 IS_TYPE = MN_IS_TYPE, // nested type
460 CALLER_SENSITIVE = MN_CALLER_SENSITIVE, // @CallerSensitive annotation detected
461 TRUSTED_FINAL = MN_TRUSTED_FINAL; // trusted final field
462
463 static final int ALL_ACCESS = Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED;
464 static final int ALL_KINDS = IS_METHOD | IS_CONSTRUCTOR | IS_FIELD | IS_TYPE;
465 static final int IS_INVOCABLE = IS_METHOD | IS_CONSTRUCTOR;
466
467 /** Utility method to query whether this member is a method or constructor. */
468 public boolean isInvocable() {
469 return anyFlagSet(IS_INVOCABLE);
470 }
471 /** Query whether this member is a method. */
472 public boolean isMethod() {
473 return allFlagsSet(IS_METHOD);
474 }
475 /** Query whether this member is a constructor. */
476 public boolean isConstructor() {
477 return allFlagsSet(IS_CONSTRUCTOR);
478 }
479 /** Query whether this member is a field. */
480 public boolean isField() {
481 return allFlagsSet(IS_FIELD);
482 }
483 /** Query whether this member is a type. */
484 public boolean isType() {
485 return allFlagsSet(IS_TYPE);
486 }
487 /** Utility method to query whether this member is neither public, private, nor protected. */
488 public boolean isPackage() {
489 return !anyFlagSet(ALL_ACCESS);
490 }
491 /** Query whether this member has a CallerSensitive annotation. */
492 public boolean isCallerSensitive() {
493 return allFlagsSet(CALLER_SENSITIVE);
494 }
495 /** Query whether this member is a trusted final field. */
496 public boolean isTrustedFinalField() {
497 return allFlagsSet(TRUSTED_FINAL | IS_FIELD);
498 }
499
500 /**
501 * Check if MemberName is a call to a method named {@code name} in class {@code declaredClass}.
502 */
503 public boolean refersTo(Class<?> declc, String n) {
504 return clazz == declc && getName().equals(n);
505 }
506
507 /** Initialize a query. It is not resolved. */
508 private void init(Class<?> defClass, String name, Object type, int flags) {
509 // defining class is allowed to be null (for a naked name/type pair)
510 //name.toString(); // null check
511 //type.equals(type); // null check
512 // fill in fields:
513 this.clazz = defClass;
514 this.name = name;
515 this.type = type;
516 this.flags = flags;
517 assert(anyFlagSet(ALL_KINDS) && this.resolution == null); // nobody should have touched this yet
518 //assert(referenceKindIsConsistent()); // do this after resolution
519 }
520
521 /**
522 * Calls down to the VM to fill in the fields. This method is
523 * synchronized to avoid racing calls.
524 */
525 private void expandFromVM() {
526 if (type != null) {
527 return;
528 }
529 if (!isResolved()) {
530 return;
531 }
532 MethodHandleNatives.expand(this);
533 }
534
535 // Capturing information from the Core Reflection API:
536 private static int flagsMods(int flags, int mods, byte refKind) {
537 assert((flags & RECOGNIZED_MODIFIERS) == 0
538 && (mods & ~RECOGNIZED_MODIFIERS) == 0
539 && (refKind & ~MN_REFERENCE_KIND_MASK) == 0);
540 return flags | mods | (refKind << MN_REFERENCE_KIND_SHIFT);
541 }
542 /** Create a name for the given reflected method. The resulting name will be in a resolved state. */
543 public MemberName(Method m) {
544 this(m, false);
545 }
546 @SuppressWarnings("LeakingThisInConstructor")
547 public MemberName(Method m, boolean wantSpecial) {
548 Objects.requireNonNull(m);
549 // fill in vmtarget, vmindex while we have m in hand:
550 MethodHandleNatives.init(this, m);
551 if (clazz == null) { // MHN.init failed
552 if (m.getDeclaringClass() == MethodHandle.class &&
553 isMethodHandleInvokeName(m.getName())) {
554 // The JVM did not reify this signature-polymorphic instance.
555 // Need a special case here.
556 // See comments on MethodHandleNatives.linkMethod.
557 MethodType type = MethodType.methodType(m.getReturnType(), m.getParameterTypes());
558 int flags = flagsMods(IS_METHOD, m.getModifiers(), REF_invokeVirtual);
559 init(MethodHandle.class, m.getName(), type, flags);
560 if (isMethodHandleInvoke())
561 return;
562 }
563 if (m.getDeclaringClass() == VarHandle.class &&
564 isVarHandleMethodInvokeName(m.getName())) {
565 // The JVM did not reify this signature-polymorphic instance.
566 // Need a special case here.
567 // See comments on MethodHandleNatives.linkMethod.
568 MethodType type = MethodType.methodType(m.getReturnType(), m.getParameterTypes());
569 int flags = flagsMods(IS_METHOD, m.getModifiers(), REF_invokeVirtual);
570 init(VarHandle.class, m.getName(), type, flags);
571 if (isVarHandleMethodInvoke())
572 return;
573 }
574 throw new LinkageError(m.toString());
575 }
576 assert(isResolved());
577 this.name = m.getName();
578 if (this.type == null)
579 this.type = new Object[] { m.getReturnType(), m.getParameterTypes() };
580 if (wantSpecial) {
581 if (isAbstract())
582 throw new AbstractMethodError(this.toString());
583 if (getReferenceKind() == REF_invokeVirtual)
584 changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual);
585 else if (getReferenceKind() == REF_invokeInterface)
586 // invokeSpecial on a default method
587 changeReferenceKind(REF_invokeSpecial, REF_invokeInterface);
588 }
589 }
590 public MemberName asSpecial() {
591 switch (getReferenceKind()) {
592 case REF_invokeSpecial: return this;
593 case REF_invokeVirtual: return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual);
594 case REF_invokeInterface: return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeInterface);
595 case REF_newInvokeSpecial: return clone().changeReferenceKind(REF_invokeSpecial, REF_newInvokeSpecial);
596 }
597 throw new IllegalArgumentException(this.toString());
598 }
599 /** If this MN is not REF_newInvokeSpecial, return a clone with that ref. kind.
600 * In that case it must already be REF_invokeSpecial.
601 */
602 public MemberName asConstructor() {
603 switch (getReferenceKind()) {
604 case REF_invokeSpecial: return clone().changeReferenceKind(REF_newInvokeSpecial, REF_invokeSpecial);
605 case REF_newInvokeSpecial: return this;
606 }
607 throw new IllegalArgumentException(this.toString());
608 }
609 /** If this MN is a REF_invokeSpecial, return a clone with the "normal" kind
610 * REF_invokeVirtual; also switch either to REF_invokeInterface if clazz.isInterface.
611 * The end result is to get a fully virtualized version of the MN.
612 * (Note that resolving in the JVM will sometimes devirtualize, changing
613 * REF_invokeVirtual of a final to REF_invokeSpecial, and REF_invokeInterface
614 * in some corner cases to either of the previous two; this transform
615 * undoes that change under the assumption that it occurred.)
616 */
617 public MemberName asNormalOriginal() {
618 byte refKind = getReferenceKind();
619 byte newRefKind = switch (refKind) {
620 case REF_invokeInterface,
621 REF_invokeVirtual,
622 REF_invokeSpecial -> clazz.isInterface() ? REF_invokeInterface : REF_invokeVirtual;
623 default -> refKind;
624 };
625 if (newRefKind == refKind)
626 return this;
627 MemberName result = clone().changeReferenceKind(newRefKind, refKind);
628 assert(this.referenceKindIsConsistentWith(result.getReferenceKind()));
629 return result;
630 }
631 /** Create a name for the given reflected constructor. The resulting name will be in a resolved state. */
632 @SuppressWarnings("LeakingThisInConstructor")
633 public MemberName(Constructor<?> ctor) {
634 Objects.requireNonNull(ctor);
635 // fill in vmtarget, vmindex while we have ctor in hand:
636 MethodHandleNatives.init(this, ctor);
637 assert(isResolved() && this.clazz != null);
638 this.name = CONSTRUCTOR_NAME;
639 if (this.type == null)
640 this.type = new Object[] { void.class, ctor.getParameterTypes() };
641 }
642 /** Create a name for the given reflected field. The resulting name will be in a resolved state.
643 */
644 public MemberName(Field fld) {
645 this(fld, false);
646 }
647 static {
648 // the following MemberName constructor relies on these ranges matching up
649 assert((REF_putStatic - REF_getStatic) == (REF_putField - REF_getField));
650 }
651 @SuppressWarnings("LeakingThisInConstructor")
652 public MemberName(Field fld, boolean makeSetter) {
653 Objects.requireNonNull(fld);
654 // fill in vmtarget, vmindex while we have fld in hand:
655 MethodHandleNatives.init(this, fld);
656 assert(isResolved() && this.clazz != null);
657 this.name = fld.getName();
658 this.type = fld.getType();
659 byte refKind = this.getReferenceKind();
660 assert(refKind == (isStatic() ? REF_getStatic : REF_getField));
661 if (makeSetter) {
662 changeReferenceKind((byte)(refKind + (REF_putStatic - REF_getStatic)), refKind);
663 }
664 }
665 public boolean isGetter() {
666 return MethodHandleNatives.refKindIsGetter(getReferenceKind());
667 }
668 public boolean isSetter() {
669 return MethodHandleNatives.refKindIsSetter(getReferenceKind());
670 }
671
672 /** Create a name for the given class. The resulting name will be in a resolved state. */
673 public MemberName(Class<?> type) {
674 init(type.getDeclaringClass(), type.getSimpleName(), type,
675 flagsMods(IS_TYPE, type.getModifiers(), REF_NONE));
676 initResolved(true);
677 }
678
679 /**
680 * Create a name for a signature-polymorphic invoker.
681 * This is a placeholder for a signature-polymorphic instance
682 * (of MH.invokeExact, etc.) that the JVM does not reify.
683 * See comments on {@link MethodHandleNatives#linkMethod}.
684 */
685 static MemberName makeMethodHandleInvoke(String name, MethodType type) {
686 return makeMethodHandleInvoke(name, type, MH_INVOKE_MODS | SYNTHETIC);
687 }
688 static MemberName makeMethodHandleInvoke(String name, MethodType type, int mods) {
689 MemberName mem = new MemberName(MethodHandle.class, name, type, REF_invokeVirtual);
690 mem.flags |= mods; // it's not resolved, but add these modifiers anyway
691 assert(mem.isMethodHandleInvoke()) : mem;
692 return mem;
693 }
694
695 static MemberName makeVarHandleMethodInvoke(String name, MethodType type) {
696 return makeVarHandleMethodInvoke(name, type, MH_INVOKE_MODS | SYNTHETIC);
697 }
698 static MemberName makeVarHandleMethodInvoke(String name, MethodType type, int mods) {
699 MemberName mem = new MemberName(VarHandle.class, name, type, REF_invokeVirtual);
700 mem.flags |= mods; // it's not resolved, but add these modifiers anyway
701 assert(mem.isVarHandleMethodInvoke()) : mem;
702 return mem;
703 }
704
705 // bare-bones constructor; the JVM will fill it in
706 MemberName() { }
707
708 // locally useful cloner
709 @Override protected MemberName clone() {
710 try {
711 return (MemberName) super.clone();
712 } catch (CloneNotSupportedException ex) {
713 throw newInternalError(ex);
714 }
715 }
716
717 /** Get the definition of this member name.
718 * This may be in a super-class of the declaring class of this member.
719 */
720 public MemberName getDefinition() {
721 if (!isResolved()) throw new IllegalStateException("must be resolved: "+this);
722 if (isType()) return this;
723 MemberName res = this.clone();
724 res.clazz = null;
725 res.type = null;
726 res.name = null;
727 res.resolution = res;
728 res.expandFromVM();
729 assert(res.getName().equals(this.getName()));
730 return res;
731 }
732
733 @Override
734 @SuppressWarnings({"deprecation", "removal"})
735 public int hashCode() {
736 // Avoid autoboxing getReferenceKind(), since this is used early and will force
737 // early initialization of Byte$ByteCache
738 return Objects.hash(clazz, new Byte(getReferenceKind()), name, getType());
739 }
740
741 @Override
742 public boolean equals(Object that) {
743 return that instanceof MemberName mn && this.equals(mn);
744 }
745
746 /** Decide if two member names have exactly the same symbolic content.
747 * Does not take into account any actual class members, so even if
748 * two member names resolve to the same actual member, they may
749 * be distinct references.
750 */
751 public boolean equals(MemberName that) {
752 if (this == that) return true;
753 if (that == null) return false;
754 return this.clazz == that.clazz
755 && this.getReferenceKind() == that.getReferenceKind()
756 && Objects.equals(this.name, that.name)
757 && Objects.equals(this.getType(), that.getType());
758 }
759
760 // Construction from symbolic parts, for queries:
761 /** Create a field or type name from the given components:
762 * Declaring class, name, type, reference kind.
763 * The declaring class may be supplied as null if this is to be a bare name and type.
764 * The resulting name will in an unresolved state.
765 */
766 public MemberName(Class<?> defClass, String name, Class<?> type, byte refKind) {
767 init(defClass, name, type, flagsMods(IS_FIELD, 0, refKind));
768 initResolved(false);
769 }
770 /** Create a method or constructor name from the given components:
771 * Declaring class, name, type, reference kind.
772 * It will be a constructor if and only if the name is {@code "<init>"}.
773 * The declaring class may be supplied as null if this is to be a bare name and type.
774 * The last argument is optional, a boolean which requests REF_invokeSpecial.
775 * The resulting name will in an unresolved state.
776 */
777 public MemberName(Class<?> defClass, String name, MethodType type, byte refKind) {
778 int initFlags = CONSTRUCTOR_NAME.equals(name) ? IS_CONSTRUCTOR : IS_METHOD;
779 init(defClass, name, type, flagsMods(initFlags, 0, refKind));
780 initResolved(false);
781 }
782 /** Create a method, constructor, or field name from the given components:
783 * Reference kind, declaring class, name, type.
784 */
785 public MemberName(byte refKind, Class<?> defClass, String name, Object type) {
786 int kindFlags;
787 if (MethodHandleNatives.refKindIsField(refKind)) {
788 kindFlags = IS_FIELD;
789 if (!(type instanceof Class))
790 throw newIllegalArgumentException("not a field type");
791 } else if (MethodHandleNatives.refKindIsMethod(refKind)) {
792 kindFlags = IS_METHOD;
793 if (!(type instanceof MethodType))
794 throw newIllegalArgumentException("not a method type");
795 } else if (refKind == REF_newInvokeSpecial) {
796 kindFlags = IS_CONSTRUCTOR;
797 if (!(type instanceof MethodType) ||
798 !CONSTRUCTOR_NAME.equals(name))
799 throw newIllegalArgumentException("not a constructor type or name");
800 } else {
801 throw newIllegalArgumentException("bad reference kind "+refKind);
802 }
803 init(defClass, name, type, flagsMods(kindFlags, 0, refKind));
804 initResolved(false);
805 }
806
807 /** Query whether this member name is resolved.
808 * A resolved member name is one for which the JVM has found
809 * a method, constructor, field, or type binding corresponding exactly to the name.
810 * (Document?)
811 */
812 public boolean isResolved() {
813 return resolution == null;
814 }
815
816 void initResolved(boolean isResolved) {
817 assert(this.resolution == null); // not initialized yet!
818 if (!isResolved)
819 this.resolution = this;
820 assert(isResolved() == isResolved);
821 }
822
823 void checkForTypeAlias(Class<?> refc) {
824 if (isInvocable()) {
825 MethodType type;
826 if (this.type instanceof MethodType mt)
827 type = mt;
828 else
829 this.type = type = getMethodType();
830 if (type.erase() == type) return;
831 if (VerifyAccess.isTypeVisible(type, refc)) return;
832 throw new LinkageError("bad method type alias: "+type+" not visible from "+refc);
833 } else {
834 Class<?> type;
835 if (this.type instanceof Class<?> cl)
836 type = cl;
837 else
838 this.type = type = getFieldType();
839 if (VerifyAccess.isTypeVisible(type, refc)) return;
840 throw new LinkageError("bad field type alias: "+type+" not visible from "+refc);
841 }
842 }
843
844
845 /** Produce a string form of this member name.
846 * For types, it is simply the type's own string (as reported by {@code toString}).
847 * For fields, it is {@code "DeclaringClass.name/type"}.
848 * For methods and constructors, it is {@code "DeclaringClass.name(ptype...)rtype"}.
849 * If the declaring class is null, the prefix {@code "DeclaringClass."} is omitted.
850 * If the member is unresolved, a prefix {@code "*."} is prepended.
851 */
852 @SuppressWarnings("LocalVariableHidesMemberVariable")
853 @Override
854 public String toString() {
855 if (isType())
856 return type.toString(); // class java.lang.String
857 // else it is a field, method, or constructor
858 StringBuilder buf = new StringBuilder();
859 if (getDeclaringClass() != null) {
860 buf.append(getName(clazz));
861 buf.append('.');
862 }
863 String name = this.name; // avoid expanding from VM
864 buf.append(name == null ? "*" : name);
865 Object type = this.type; // avoid expanding from VM
866 if (!isInvocable()) {
867 buf.append('/');
868 buf.append(type == null ? "*" : getName(type));
869 } else {
870 buf.append(type == null ? "(*)*" : getName(type));
871 }
872 byte refKind = getReferenceKind();
873 if (refKind != REF_NONE) {
874 buf.append('/');
875 buf.append(MethodHandleNatives.refKindName(refKind));
876 }
877 //buf.append("#").append(System.identityHashCode(this));
878 return buf.toString();
879 }
880 private static String getName(Object obj) {
881 if (obj instanceof Class<?> cl)
882 return cl.getName();
883 return String.valueOf(obj);
884 }
885
886 public IllegalAccessException makeAccessException(String message, Object from) {
887 message = message + ": " + this;
888 if (from != null) {
889 if (from == MethodHandles.publicLookup()) {
890 message += ", from public Lookup";
891 } else {
892 Module m;
893 Class<?> plc;
894 if (from instanceof MethodHandles.Lookup lookup) {
895 from = lookup.lookupClass();
896 m = lookup.lookupClass().getModule();
897 plc = lookup.previousLookupClass();
898 } else {
899 m = ((Class<?>)from).getModule();
900 plc = null;
901 }
902 message += ", from " + from + " (" + m + ")";
903 if (plc != null) {
904 message += ", previous lookup " +
905 plc.getName() + " (" + plc.getModule() + ")";
906 }
907 }
908 }
909 return new IllegalAccessException(message);
910 }
911 private String message() {
912 if (isResolved())
913 return "no access";
914 else if (isConstructor())
915 return "no such constructor";
916 else if (isMethod())
917 return "no such method";
918 else
919 return "no such field";
920 }
921 public ReflectiveOperationException makeAccessException() {
922 String message = message() + ": " + this;
923 ReflectiveOperationException ex;
924 if (isResolved() || !(resolution instanceof NoSuchMethodError ||
925 resolution instanceof NoSuchFieldError))
926 ex = new IllegalAccessException(message);
927 else if (isConstructor())
928 ex = new NoSuchMethodException(message);
929 else if (isMethod())
930 ex = new NoSuchMethodException(message);
931 else
932 ex = new NoSuchFieldException(message);
933 if (resolution instanceof Throwable res)
934 ex.initCause(res);
935 return ex;
936 }
937
938 /** Actually making a query requires an access check. */
939 /*non-public*/
940 static Factory getFactory() {
941 return Factory.INSTANCE;
942 }
943 /** A factory type for resolving member names with the help of the VM.
944 * TBD: Define access-safe public constructors for this factory.
945 */
946 /*non-public*/
947 static class Factory {
948 private Factory() { } // singleton pattern
949 static final Factory INSTANCE = new Factory();
950
951 /** Produce a resolved version of the given member.
952 * Super types are searched (for inherited members) if {@code searchSupers} is true.
953 * Access checking is performed on behalf of the given {@code lookupClass}.
954 * If lookup fails or access is not permitted, null is returned.
955 * Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
956 */
957 private MemberName resolve(byte refKind, MemberName ref, Class<?> lookupClass, int allowedModes,
958 boolean speculativeResolve) {
959 MemberName m = ref.clone(); // JVM will side-effect the ref
960 assert(refKind == m.getReferenceKind());
961 try {
962 // There are 4 entities in play here:
963 // * LC: lookupClass
964 // * REFC: symbolic reference class (MN.clazz before resolution);
965 // * DEFC: resolved method holder (MN.clazz after resolution);
966 // * PTYPES: parameter types (MN.type)
967 //
968 // What we care about when resolving a MemberName is consistency between DEFC and PTYPES.
969 // We do type alias (TA) checks on DEFC to ensure that. DEFC is not known until the JVM
970 // finishes the resolution, so do TA checks right after MHN.resolve() is over.
971 //
972 // All parameters passed by a caller are checked against MH type (PTYPES) on every invocation,
973 // so it is safe to call a MH from any context.
974 //
975 // REFC view on PTYPES doesn't matter, since it is used only as a starting point for resolution and doesn't
976 // participate in method selection.
977 m = MethodHandleNatives.resolve(m, lookupClass, allowedModes, speculativeResolve);
978 if (m == null && speculativeResolve) {
979 return null;
980 }
981 m.checkForTypeAlias(m.getDeclaringClass());
982 m.resolution = null;
983 } catch (ClassNotFoundException | LinkageError ex) {
984 // JVM reports that the "bytecode behavior" would get an error
985 assert(!m.isResolved());
986 m.resolution = ex;
987 return m;
988 }
989 assert(m.referenceKindIsConsistent());
990 m.initResolved(true);
991 assert(m.vminfoIsConsistent());
992 return m;
993 }
994 /** Produce a resolved version of the given member.
995 * Super types are searched (for inherited members) if {@code searchSupers} is true.
996 * Access checking is performed on behalf of the given {@code lookupClass}.
997 * If lookup fails or access is not permitted, a {@linkplain ReflectiveOperationException} is thrown.
998 * Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
999 */
1000 public <NoSuchMemberException extends ReflectiveOperationException>
1001 MemberName resolveOrFail(byte refKind, MemberName m,
1002 Class<?> lookupClass, int allowedModes,
1003 Class<NoSuchMemberException> nsmClass)
1004 throws IllegalAccessException, NoSuchMemberException {
1005 assert lookupClass != null || allowedModes == LM_TRUSTED;
1006 MemberName result = resolve(refKind, m, lookupClass, allowedModes, false);
1007 if (result.isResolved())
1008 return result;
1009 ReflectiveOperationException ex = result.makeAccessException();
1010 if (ex instanceof IllegalAccessException iae) throw iae;
1011 throw nsmClass.cast(ex);
1012 }
1013 /** Produce a resolved version of the given member.
1014 * Super types are searched (for inherited members) if {@code searchSupers} is true.
1015 * Access checking is performed on behalf of the given {@code lookupClass}.
1016 * If lookup fails or access is not permitted, return null.
1017 * Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
1018 */
1019 public MemberName resolveOrNull(byte refKind, MemberName m, Class<?> lookupClass, int allowedModes) {
1020 assert lookupClass != null || allowedModes == LM_TRUSTED;
1021 MemberName result = resolve(refKind, m, lookupClass, allowedModes, true);
1022 if (result != null && result.isResolved())
1023 return result;
1024 return null;
1025 }
1026 }
1027 }