1 /*
2 * Copyright (c) 2008, 2022, 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 /*non-public*/
70 final class ResolvedMethodName {
71 //@Injected JVM_Method* vmtarget;
72 //@Injected Class<?> vmholder;
73 }
74
75 /*non-public*/
76 final class MemberName implements Member, Cloneable {
77 private Class<?> clazz; // class in which the member is defined
78 private String name; // may be null if not yet materialized
79 private Object type; // may be null if not yet materialized
80 private int flags; // modifier bits; see reflect.Modifier
81 private ResolvedMethodName method; // cached resolved method information
82 //@Injected intptr_t vmindex; // vtable index or offset of resolved member
83 Object resolution; // if null, this guy is resolved
84
85 /** Return the declaring class of this member.
86 * In the case of a bare name and type, the declaring class will be null.
87 */
88 public Class<?> getDeclaringClass() {
89 return clazz;
90 }
91
92 /** Utility method producing the class loader of the declaring class. */
93 public ClassLoader getClassLoader() {
94 return clazz.getClassLoader();
95 }
96
97 /** Return the simple name of this member.
98 * For a type, it is the same as {@link Class#getSimpleName}.
99 * For a method or field, it is the simple name of the member.
100 * For an identity object constructor, it is {@code "<init>"}.
101 * For a value class static factory method, it is {@code "<vnew>"}.
102 */
103 public String getName() {
104 if (name == null) {
105 expandFromVM();
106 if (name == null) {
107 return null;
108 }
109 }
110 return name;
111 }
112
113 public MethodType getMethodOrFieldType() {
114 if (isInvocable())
115 return getMethodType();
116 if (isGetter())
117 return MethodType.methodType(getFieldType());
118 if (isSetter())
119 return MethodType.methodType(void.class, getFieldType());
120 throw new InternalError("not a method or field: "+this);
121 }
122
123 /** Return the declared type of this member, which
124 * must be a method or constructor.
125 */
126 public MethodType getMethodType() {
127 if (type == null) {
128 expandFromVM();
129 if (type == null) {
130 return null;
131 }
132 }
133 if (!isInvocable()) {
134 throw newIllegalArgumentException("not invocable, no method type");
135 }
136
137 {
138 // Get a snapshot of type which doesn't get changed by racing threads.
139 final Object type = this.type;
140 if (type instanceof MethodType) {
141 return (MethodType) type;
142 }
143 }
144
145 // type is not a MethodType yet. Convert it thread-safely.
146 synchronized (this) {
147 if (type instanceof String sig) {
148 MethodType res = MethodType.fromDescriptor(sig, getClassLoader());
149 type = res;
150 } else if (type instanceof Object[] typeInfo) {
151 Class<?>[] ptypes = (Class<?>[]) typeInfo[1];
152 Class<?> rtype = (Class<?>) typeInfo[0];
153 MethodType res = MethodType.methodType(rtype, ptypes, true);
154 type = res;
155 }
156 // Make sure type is a MethodType for racing threads.
157 assert type instanceof MethodType : "bad method type " + type;
158 }
159 return (MethodType) type;
160 }
161
162 /** Return the descriptor of this member, which
163 * must be a method or constructor.
164 */
165 String getMethodDescriptor() {
166 if (type == null) {
167 expandFromVM();
168 if (type == null) {
169 return null;
170 }
171 }
172 if (!isInvocable()) {
173 throw newIllegalArgumentException("not invocable, no method type");
174 }
175
176 // Get a snapshot of type which doesn't get changed by racing threads.
177 final Object type = this.type;
178 if (type instanceof String) {
179 return (String) type;
180 } else {
181 return getMethodType().toMethodDescriptorString();
182 }
183 }
184
185 /** Return the actual type under which this method or constructor must be invoked.
186 * For non-static methods or constructors, this is the type with a leading parameter,
187 * a reference to declaring class. For static methods, it is the same as the declared type.
188 */
189 public MethodType getInvocationType() {
190 MethodType itype = getMethodOrFieldType();
191 Class<?> c = PrimitiveClass.isPrimitiveClass(clazz) ? PrimitiveClass.asValueType(clazz) : clazz;
192 if (isObjectConstructor() && getReferenceKind() == REF_newInvokeSpecial)
193 return itype.changeReturnType(c);
194 if (!isStatic())
195 return itype.insertParameterTypes(0, c);
196 return itype;
197 }
198
199 /** Return the declared type of this member, which
200 * must be a field or type.
201 * If it is a type member, that type itself is returned.
202 */
203 public Class<?> getFieldType() {
204 if (type == null) {
205 expandFromVM();
206 if (type == null) {
207 return null;
208 }
209 }
210 if (isInvocable()) {
211 throw newIllegalArgumentException("not a field or nested class, no simple type");
212 }
213
214 {
215 // Get a snapshot of type which doesn't get changed by racing threads.
216 final Object type = this.type;
217 if (type instanceof Class<?>) {
218 return (Class<?>) type;
219 }
220 }
221
222 // type is not a Class yet. Convert it thread-safely.
223 synchronized (this) {
224 if (type instanceof String sig) {
225 MethodType mtype = MethodType.fromDescriptor("()"+sig, getClassLoader());
226 Class<?> res = mtype.returnType();
227 type = res;
228 }
229 // Make sure type is a Class for racing threads.
230 assert type instanceof Class<?> : "bad field type " + type;
231 }
232 return (Class<?>) type;
233 }
234
235 /** Utility method to produce either the method type or field type of this member. */
236 public Object getType() {
237 return (isInvocable() ? getMethodType() : getFieldType());
238 }
239
240 /** Return the modifier flags of this member.
241 * @see java.lang.reflect.Modifier
242 */
243 public int getModifiers() {
244 return (flags & RECOGNIZED_MODIFIERS);
245 }
246
247 /** Return the reference kind of this member, or zero if none.
248 */
249 public byte getReferenceKind() {
250 return (byte) ((flags >>> MN_REFERENCE_KIND_SHIFT) & MN_REFERENCE_KIND_MASK);
251 }
252 private boolean referenceKindIsConsistent() {
253 byte refKind = getReferenceKind();
254 if (refKind == REF_NONE) return isType();
255 if (isField()) {
256 assert(staticIsConsistent());
257 assert(MethodHandleNatives.refKindIsField(refKind));
258 } else if (isObjectConstructor()) {
259 assert(refKind == REF_newInvokeSpecial || refKind == REF_invokeSpecial);
260 } else if (isMethod()) {
261 assert(staticIsConsistent());
262 assert(MethodHandleNatives.refKindIsMethod(refKind));
263 if (clazz.isInterface())
264 assert(refKind == REF_invokeInterface ||
265 refKind == REF_invokeStatic ||
266 refKind == REF_invokeSpecial ||
267 refKind == REF_invokeVirtual && isObjectPublicMethod());
268 } else {
269 assert(false);
270 }
271 return true;
272 }
273 private boolean isObjectPublicMethod() {
274 if (clazz == Object.class) return true;
275 MethodType mtype = getMethodType();
276 if (name.equals("toString") && mtype.returnType() == String.class && mtype.parameterCount() == 0)
277 return true;
278 if (name.equals("hashCode") && mtype.returnType() == int.class && mtype.parameterCount() == 0)
279 return true;
280 if (name.equals("equals") && mtype.returnType() == boolean.class && mtype.parameterCount() == 1 && mtype.parameterType(0) == Object.class)
281 return true;
282 return false;
283 }
284
285 /*non-public*/
286 boolean referenceKindIsConsistentWith(int originalRefKind) {
287 int refKind = getReferenceKind();
288 if (refKind == originalRefKind) return true;
289 if (getClass().desiredAssertionStatus()) {
290 switch (originalRefKind) {
291 case REF_invokeInterface -> {
292 // Looking up an interface method, can get (e.g.) Object.hashCode
293 assert (refKind == REF_invokeVirtual || refKind == REF_invokeSpecial) : this;
294 }
295 case REF_invokeVirtual, REF_newInvokeSpecial -> {
296 // Looked up a virtual, can get (e.g.) final String.hashCode.
297 assert (refKind == REF_invokeSpecial) : this;
298 }
299 default -> {
300 assert (false) : this + " != " + MethodHandleNatives.refKindName((byte) originalRefKind);
301 }
302 }
303 }
304 return true;
305 }
306 private boolean staticIsConsistent() {
307 byte refKind = getReferenceKind();
308 return MethodHandleNatives.refKindIsStatic(refKind) == isStatic() || getModifiers() == 0;
309 }
310 private boolean vminfoIsConsistent() {
311 byte refKind = getReferenceKind();
312 assert(isResolved()); // else don't call
313 Object vminfo = MethodHandleNatives.getMemberVMInfo(this);
314 assert(vminfo instanceof Object[]);
315 long vmindex = (Long) ((Object[])vminfo)[0];
316 Object vmtarget = ((Object[])vminfo)[1];
317 if (MethodHandleNatives.refKindIsField(refKind)) {
318 assert(vmindex >= 0) : vmindex + ":" + this;
319 assert(vmtarget instanceof Class);
320 } else {
321 if (MethodHandleNatives.refKindDoesDispatch(refKind))
322 assert(vmindex >= 0) : vmindex + ":" + this;
323 else
324 assert(vmindex < 0) : vmindex;
325 assert(vmtarget instanceof MemberName) : vmtarget + " in " + this;
326 }
327 return true;
328 }
329
330 private MemberName changeReferenceKind(byte refKind, byte oldKind) {
331 assert(getReferenceKind() == oldKind && MethodHandleNatives.refKindIsValid(refKind));
332 flags += (((int)refKind - oldKind) << MN_REFERENCE_KIND_SHIFT);
333 return this;
334 }
335
336 private boolean matchingFlagsSet(int mask, int flags) {
337 return (this.flags & mask) == flags;
338 }
339 private boolean allFlagsSet(int flags) {
340 return (this.flags & flags) == flags;
341 }
342 private boolean anyFlagSet(int flags) {
343 return (this.flags & flags) != 0;
344 }
345
346 /** Utility method to query if this member is a method handle invocation (invoke or invokeExact).
347 */
348 public boolean isMethodHandleInvoke() {
349 final int bits = MH_INVOKE_MODS &~ Modifier.PUBLIC;
350 final int negs = Modifier.STATIC;
351 if (matchingFlagsSet(bits | negs, bits) && clazz == MethodHandle.class) {
352 return isMethodHandleInvokeName(name);
353 }
354 return false;
355 }
356 public static boolean isMethodHandleInvokeName(String name) {
357 return switch (name) {
358 case "invoke", "invokeExact" -> true;
359 default -> false;
360 };
361 }
362 public boolean isVarHandleMethodInvoke() {
363 final int bits = MH_INVOKE_MODS &~ Modifier.PUBLIC;
364 final int negs = Modifier.STATIC;
365 if (matchingFlagsSet(bits | negs, bits) && clazz == VarHandle.class) {
366 return isVarHandleMethodInvokeName(name);
367 }
368 return false;
369 }
370 public static boolean isVarHandleMethodInvokeName(String name) {
371 try {
372 VarHandle.AccessMode.valueFromMethodName(name);
373 return true;
374 } catch (IllegalArgumentException e) {
375 return false;
376 }
377 }
378 private static final int MH_INVOKE_MODS = Modifier.NATIVE | Modifier.FINAL | Modifier.PUBLIC;
379
380 /** Utility method to query the modifier flags of this member. */
381 public boolean isStatic() {
382 return Modifier.isStatic(flags);
383 }
384 /** Utility method to query the modifier flags of this member. */
385 public boolean isPublic() {
386 return Modifier.isPublic(flags);
387 }
388 /** Utility method to query the modifier flags of this member. */
389 public boolean isPrivate() {
390 return Modifier.isPrivate(flags);
391 }
392 /** Utility method to query the modifier flags of this member. */
393 public boolean isProtected() {
394 return Modifier.isProtected(flags);
395 }
396 /** Utility method to query the modifier flags of this member. */
397 public boolean isFinal() {
398 // all fields declared in a value type are effectively final
399 assert(!clazz.isValue() || !isField() || Modifier.isFinal(flags));
400 return Modifier.isFinal(flags);
401 }
402 /** Utility method to query whether this member or its defining class is final. */
403 public boolean canBeStaticallyBound() {
404 return Modifier.isFinal(flags | clazz.getModifiers());
405 }
406 /** Utility method to query the modifier flags of this member. */
407 public boolean isVolatile() {
408 return Modifier.isVolatile(flags);
409 }
410 /** Utility method to query the modifier flags of this member. */
411 public boolean isAbstract() {
412 return Modifier.isAbstract(flags);
413 }
414 /** Utility method to query the modifier flags of this member. */
415 public boolean isNative() {
416 return Modifier.isNative(flags);
417 }
418 // let the rest (native, volatile, transient, etc.) be tested via Modifier.isFoo
419
420 // unofficial modifier flags, used by HotSpot:
421 static final int BRIDGE = 0x00000040;
422 static final int VARARGS = 0x00000080;
423 static final int SYNTHETIC = 0x00001000;
424 static final int ANNOTATION = 0x00002000;
425 static final int ENUM = 0x00004000;
426
427 /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
428 public boolean isBridge() {
429 return allFlagsSet(IS_METHOD | BRIDGE);
430 }
431 /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
432 public boolean isVarargs() {
433 return allFlagsSet(VARARGS) && isInvocable();
434 }
435 /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
436 public boolean isSynthetic() {
437 return allFlagsSet(SYNTHETIC);
438 }
439
440 /** Query whether this member is a flattened field */
441 public boolean isFlattened() { return (flags & MN_FLATTENED) == MN_FLATTENED; }
442
443 /** Query whether this member is a field of a primitive class. */
444 public boolean isInlineableField() {
445 if (isField()) {
446 Class<?> type = getFieldType();
447 return PrimitiveClass.isPrimitiveValueType(type) || (type.isValue() && !PrimitiveClass.isPrimitiveClass(type));
448 }
449 return false;
450 }
451
452 static final String CONSTRUCTOR_NAME = "<init>";
453 static final String VALUE_FACTORY_NAME = "<vnew>"; // the ever-popular
454
455 // modifiers exported by the JVM:
456 static final int RECOGNIZED_MODIFIERS = 0xFFFF;
457
458 // private flags, not part of RECOGNIZED_MODIFIERS:
459 static final int
460 IS_METHOD = MN_IS_METHOD, // method (not object constructor)
461 IS_OBJECT_CONSTRUCTOR = MN_IS_OBJECT_CONSTRUCTOR, // object constructor
462 IS_FIELD = MN_IS_FIELD, // field
463 IS_TYPE = MN_IS_TYPE, // nested type
464 CALLER_SENSITIVE = MN_CALLER_SENSITIVE, // @CallerSensitive annotation detected
465 TRUSTED_FINAL = MN_TRUSTED_FINAL; // trusted final field
466
467 static final int ALL_ACCESS = Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED;
468 static final int ALL_KINDS = IS_METHOD | IS_OBJECT_CONSTRUCTOR | IS_FIELD | IS_TYPE;
469 static final int IS_INVOCABLE = IS_METHOD | IS_OBJECT_CONSTRUCTOR;
470
471 /** Utility method to query whether this member is a method or constructor. */
472 public boolean isInvocable() {
473 return anyFlagSet(IS_INVOCABLE);
474 }
475 /** Query whether this member is a method. */
476 public boolean isMethod() {
477 return allFlagsSet(IS_METHOD);
478 }
479 /** Query whether this member is a constructor. */
480 public boolean isObjectConstructor() {
481 return allFlagsSet(IS_OBJECT_CONSTRUCTOR);
482 }
483 /** Query whether this member is an object constructor or static <init> factory */
484 public boolean isStaticValueFactoryMethod() {
485 return VALUE_FACTORY_NAME.equals(name) && isMethod();
486 }
487
488 /** Query whether this member is a field. */
489 public boolean isField() {
490 return allFlagsSet(IS_FIELD);
491 }
492 /** Query whether this member is a type. */
493 public boolean isType() {
494 return allFlagsSet(IS_TYPE);
495 }
496 /** Utility method to query whether this member is neither public, private, nor protected. */
497 public boolean isPackage() {
498 return !anyFlagSet(ALL_ACCESS);
499 }
500 /** Query whether this member has a CallerSensitive annotation. */
501 public boolean isCallerSensitive() {
502 return allFlagsSet(CALLER_SENSITIVE);
503 }
504 /** Query whether this member is a trusted final field. */
505 public boolean isTrustedFinalField() {
506 return allFlagsSet(TRUSTED_FINAL | IS_FIELD);
507 }
508
509 /**
510 * Check if MemberName is a call to a method named {@code name} in class {@code declaredClass}.
511 */
512 public boolean refersTo(Class<?> declc, String n) {
513 return clazz == declc && getName().equals(n);
514 }
515
516 /** Initialize a query. It is not resolved. */
517 private void init(Class<?> defClass, String name, Object type, int flags) {
518 // defining class is allowed to be null (for a naked name/type pair)
519 //name.toString(); // null check
520 //type.equals(type); // null check
521 // fill in fields:
522 this.clazz = defClass;
523 this.name = name;
524 this.type = type;
525 this.flags = flags;
526 assert(anyFlagSet(ALL_KINDS) && this.resolution == null); // nobody should have touched this yet
527 //assert(referenceKindIsConsistent()); // do this after resolution
528 }
529
530 /**
531 * Calls down to the VM to fill in the fields. This method is
532 * synchronized to avoid racing calls.
533 */
534 private void expandFromVM() {
535 if (type != null) {
536 return;
537 }
538 if (!isResolved()) {
539 return;
540 }
541 MethodHandleNatives.expand(this);
542 }
543
544 // Capturing information from the Core Reflection API:
545 private static int flagsMods(int flags, int mods, byte refKind) {
546 assert((flags & RECOGNIZED_MODIFIERS) == 0
547 && (mods & ~RECOGNIZED_MODIFIERS) == 0
548 && (refKind & ~MN_REFERENCE_KIND_MASK) == 0);
549 return flags | mods | (refKind << MN_REFERENCE_KIND_SHIFT);
550 }
551 /** Create a name for the given reflected method. The resulting name will be in a resolved state. */
552 public MemberName(Method m) {
553 this(m, false);
554 }
555 @SuppressWarnings("LeakingThisInConstructor")
556 public MemberName(Method m, boolean wantSpecial) {
557 Objects.requireNonNull(m);
558 // fill in vmtarget, vmindex while we have m in hand:
559 MethodHandleNatives.init(this, m);
560 if (clazz == null) { // MHN.init failed
561 if (m.getDeclaringClass() == MethodHandle.class &&
562 isMethodHandleInvokeName(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(MethodHandle.class, m.getName(), type, flags);
569 if (isMethodHandleInvoke())
570 return;
571 }
572 if (m.getDeclaringClass() == VarHandle.class &&
573 isVarHandleMethodInvokeName(m.getName())) {
574 // The JVM did not reify this signature-polymorphic instance.
575 // Need a special case here.
576 // See comments on MethodHandleNatives.linkMethod.
577 MethodType type = MethodType.methodType(m.getReturnType(), m.getParameterTypes());
578 int flags = flagsMods(IS_METHOD, m.getModifiers(), REF_invokeVirtual);
579 init(VarHandle.class, m.getName(), type, flags);
580 if (isVarHandleMethodInvoke())
581 return;
582 }
583 throw new LinkageError(m.toString());
584 }
585 assert(isResolved());
586 this.name = m.getName();
587 if (this.type == null)
588 this.type = new Object[] { m.getReturnType(), m.getParameterTypes() };
589 if (wantSpecial) {
590 if (isAbstract())
591 throw new AbstractMethodError(this.toString());
592 if (getReferenceKind() == REF_invokeVirtual)
593 changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual);
594 else if (getReferenceKind() == REF_invokeInterface)
595 // invokeSpecial on a default method
596 changeReferenceKind(REF_invokeSpecial, REF_invokeInterface);
597 }
598 }
599 public MemberName asSpecial() {
600 switch (getReferenceKind()) {
601 case REF_invokeSpecial: return this;
602 case REF_invokeVirtual: return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual);
603 case REF_invokeInterface: return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeInterface);
604 case REF_newInvokeSpecial: return clone().changeReferenceKind(REF_invokeSpecial, REF_newInvokeSpecial);
605 }
606 throw new IllegalArgumentException(this.toString());
607 }
608 /** If this MN is not REF_newInvokeSpecial, return a clone with that ref. kind.
609 * In that case it must already be REF_invokeSpecial.
610 */
611 public MemberName asObjectConstructor() {
612 switch (getReferenceKind()) {
613 case REF_invokeSpecial: return clone().changeReferenceKind(REF_newInvokeSpecial, REF_invokeSpecial);
614 case REF_newInvokeSpecial: return this;
615 }
616 throw new IllegalArgumentException(this.toString());
617 }
618 /** If this MN is a REF_invokeSpecial, return a clone with the "normal" kind
619 * REF_invokeVirtual; also switch either to REF_invokeInterface if clazz.isInterface.
620 * The end result is to get a fully virtualized version of the MN.
621 * (Note that resolving in the JVM will sometimes devirtualize, changing
622 * REF_invokeVirtual of a final to REF_invokeSpecial, and REF_invokeInterface
623 * in some corner cases to either of the previous two; this transform
624 * undoes that change under the assumption that it occurred.)
625 */
626 public MemberName asNormalOriginal() {
627 byte refKind = getReferenceKind();
628 byte newRefKind = switch (refKind) {
629 case REF_invokeInterface,
630 REF_invokeVirtual,
631 REF_invokeSpecial -> clazz.isInterface() ? REF_invokeInterface : REF_invokeVirtual;
632 default -> refKind;
633 };
634 if (newRefKind == refKind)
635 return this;
636 MemberName result = clone().changeReferenceKind(newRefKind, refKind);
637 assert(this.referenceKindIsConsistentWith(result.getReferenceKind()));
638 return result;
639 }
640 /** Create a name for the given reflected constructor. The resulting name will be in a resolved state. */
641 @SuppressWarnings("LeakingThisInConstructor")
642 public MemberName(Constructor<?> ctor) {
643 Objects.requireNonNull(ctor);
644 // fill in vmtarget, vmindex while we have ctor in hand:
645 MethodHandleNatives.init(this, ctor);
646 assert(isResolved() && this.clazz != null);
647 this.name = this.clazz.isValue() ? VALUE_FACTORY_NAME : CONSTRUCTOR_NAME;
648 if (this.type == null) {
649 Class<?> rtype = void.class;
650 if (isStatic()) { // a value class static factory, not a true constructor
651 rtype = getDeclaringClass();
652 }
653 this.type = new Object[] { rtype, ctor.getParameterTypes() };
654 }
655 }
656 /** Create a name for the given reflected field. The resulting name will be in a resolved state.
657 */
658 public MemberName(Field fld) {
659 this(fld, false);
660 }
661 static {
662 // the following MemberName constructor relies on these ranges matching up
663 assert((REF_putStatic - REF_getStatic) == (REF_putField - REF_getField));
664 }
665 @SuppressWarnings("LeakingThisInConstructor")
666 public MemberName(Field fld, boolean makeSetter) {
667 Objects.requireNonNull(fld);
668 // fill in vmtarget, vmindex while we have fld in hand:
669 MethodHandleNatives.init(this, fld);
670 assert(isResolved() && this.clazz != null);
671 this.name = fld.getName();
672 this.type = fld.getType();
673 byte refKind = this.getReferenceKind();
674 assert(refKind == (isStatic() ? REF_getStatic : REF_getField));
675 if (makeSetter) {
676 changeReferenceKind((byte)(refKind + (REF_putStatic - REF_getStatic)), refKind);
677 }
678 }
679 public boolean isGetter() {
680 return MethodHandleNatives.refKindIsGetter(getReferenceKind());
681 }
682 public boolean isSetter() {
683 return MethodHandleNatives.refKindIsSetter(getReferenceKind());
684 }
685
686 /** Create a name for the given class. The resulting name will be in a resolved state. */
687 public MemberName(Class<?> type) {
688 init(type.getDeclaringClass(), type.getSimpleName(), type,
689 flagsMods(IS_TYPE, type.getModifiers(), REF_NONE));
690 initResolved(true);
691 }
692
693 /**
694 * Create a name for a signature-polymorphic invoker.
695 * This is a placeholder for a signature-polymorphic instance
696 * (of MH.invokeExact, etc.) that the JVM does not reify.
697 * See comments on {@link MethodHandleNatives#linkMethod}.
698 */
699 static MemberName makeMethodHandleInvoke(String name, MethodType type) {
700 return makeMethodHandleInvoke(name, type, MH_INVOKE_MODS | SYNTHETIC);
701 }
702 static MemberName makeMethodHandleInvoke(String name, MethodType type, int mods) {
703 MemberName mem = new MemberName(MethodHandle.class, name, type, REF_invokeVirtual);
704 mem.flags |= mods; // it's not resolved, but add these modifiers anyway
705 assert(mem.isMethodHandleInvoke()) : mem;
706 return mem;
707 }
708
709 static MemberName makeVarHandleMethodInvoke(String name, MethodType type) {
710 return makeVarHandleMethodInvoke(name, type, MH_INVOKE_MODS | SYNTHETIC);
711 }
712 static MemberName makeVarHandleMethodInvoke(String name, MethodType type, int mods) {
713 MemberName mem = new MemberName(VarHandle.class, name, type, REF_invokeVirtual);
714 mem.flags |= mods; // it's not resolved, but add these modifiers anyway
715 assert(mem.isVarHandleMethodInvoke()) : mem;
716 return mem;
717 }
718
719 // bare-bones constructor; the JVM will fill it in
720 MemberName() { }
721
722 // locally useful cloner
723 @Override protected MemberName clone() {
724 try {
725 return (MemberName) super.clone();
726 } catch (CloneNotSupportedException ex) {
727 throw newInternalError(ex);
728 }
729 }
730
731 /** Get the definition of this member name.
732 * This may be in a super-class of the declaring class of this member.
733 */
734 public MemberName getDefinition() {
735 if (!isResolved()) throw new IllegalStateException("must be resolved: "+this);
736 if (isType()) return this;
737 MemberName res = this.clone();
738 res.clazz = null;
739 res.type = null;
740 res.name = null;
741 res.resolution = res;
742 res.expandFromVM();
743 assert(res.getName().equals(this.getName()));
744 return res;
745 }
746
747 @Override
748 @SuppressWarnings({"deprecation", "removal"})
749 public int hashCode() {
750 // Avoid autoboxing getReferenceKind(), since this is used early and will force
751 // early initialization of Byte$ByteCache
752 return Objects.hash(clazz, new Byte(getReferenceKind()), name, getType());
753 }
754
755 @Override
756 public boolean equals(Object that) {
757 return (that instanceof MemberName && this.equals((MemberName)that));
758 }
759
760 /** Decide if two member names have exactly the same symbolic content.
761 * Does not take into account any actual class members, so even if
762 * two member names resolve to the same actual member, they may
763 * be distinct references.
764 */
765 public boolean equals(MemberName that) {
766 if (this == that) return true;
767 if (that == null) return false;
768 return this.clazz == that.clazz
769 && this.getReferenceKind() == that.getReferenceKind()
770 && Objects.equals(this.name, that.name)
771 && Objects.equals(this.getType(), that.getType());
772 }
773
774 // Construction from symbolic parts, for queries:
775 /** Create a field or type name from the given components:
776 * Declaring class, name, type, reference kind.
777 * The declaring class may be supplied as null if this is to be a bare name and type.
778 * The resulting name will in an unresolved state.
779 */
780 public MemberName(Class<?> defClass, String name, Class<?> type, byte refKind) {
781 init(defClass, name, type, flagsMods(IS_FIELD, 0, refKind));
782 initResolved(false);
783 }
784 /** Create a method or constructor name from the given components:
785 * Declaring class, name, type, reference kind.
786 * It will be an object constructor if and only if the name is {@code "<init>"}.
787 * It will be a value class instance factory method if and only if the name is {@code "<vnew>"}.
788 * The declaring class may be supplied as null if this is to be a bare name and type.
789 * The last argument is optional, a boolean which requests REF_invokeSpecial.
790 * The resulting name will in an unresolved state.
791 */
792 public MemberName(Class<?> defClass, String name, MethodType type, byte refKind) {
793 int initFlags = CONSTRUCTOR_NAME.equals(name) ? IS_OBJECT_CONSTRUCTOR : IS_METHOD;
794 init(defClass, name, type, flagsMods(initFlags, 0, refKind));
795 initResolved(false);
796 }
797 /** Create a method, constructor, or field name from the given components:
798 * Reference kind, declaring class, name, type.
799 */
800 public MemberName(byte refKind, Class<?> defClass, String name, Object type) {
801 int kindFlags;
802 if (MethodHandleNatives.refKindIsField(refKind)) {
803 kindFlags = IS_FIELD;
804 if (!(type instanceof Class))
805 throw newIllegalArgumentException("not a field type");
806 } else if (MethodHandleNatives.refKindIsMethod(refKind)) {
807 kindFlags = IS_METHOD;
808 if (!(type instanceof MethodType))
809 throw newIllegalArgumentException("not a method type");
810 } else if (refKind == REF_newInvokeSpecial) {
811 kindFlags = IS_OBJECT_CONSTRUCTOR;
812 if (!(type instanceof MethodType) ||
813 !CONSTRUCTOR_NAME.equals(name))
814 throw newIllegalArgumentException("not a constructor type or name");
815 } else {
816 throw newIllegalArgumentException("bad reference kind "+refKind);
817 }
818 init(defClass, name, type, flagsMods(kindFlags, 0, refKind));
819 initResolved(false);
820 }
821
822 /** Query whether this member name is resolved.
823 * A resolved member name is one for which the JVM has found
824 * a method, constructor, field, or type binding corresponding exactly to the name.
825 * (Document?)
826 */
827 public boolean isResolved() {
828 return resolution == null;
829 }
830
831 void initResolved(boolean isResolved) {
832 assert(this.resolution == null); // not initialized yet!
833 if (!isResolved)
834 this.resolution = this;
835 assert(isResolved() == isResolved);
836 }
837
838 void checkForTypeAlias(Class<?> refc) {
839 if (isInvocable()) {
840 MethodType type;
841 if (this.type instanceof MethodType)
842 type = (MethodType) this.type;
843 else
844 this.type = type = getMethodType();
845 if (type.erase() == type) return;
846 if (VerifyAccess.isTypeVisible(type, refc)) return;
847 throw new LinkageError("bad method type alias: "+type+" not visible from "+refc);
848 } else {
849 Class<?> type;
850 if (this.type instanceof Class<?>)
851 type = (Class<?>) this.type;
852 else
853 this.type = type = getFieldType();
854 if (VerifyAccess.isTypeVisible(type, refc)) return;
855 throw new LinkageError("bad field type alias: "+type+" not visible from "+refc);
856 }
857 }
858
859
860 /** Produce a string form of this member name.
861 * For types, it is simply the type's own string (as reported by {@code toString}).
862 * For fields, it is {@code "DeclaringClass.name/type"}.
863 * For methods and constructors, it is {@code "DeclaringClass.name(ptype...)rtype"}.
864 * If the declaring class is null, the prefix {@code "DeclaringClass."} is omitted.
865 * If the member is unresolved, a prefix {@code "*."} is prepended.
866 */
867 @SuppressWarnings("LocalVariableHidesMemberVariable")
868 @Override
869 public String toString() {
870 if (isType())
871 return type.toString(); // class java.lang.String
872 // else it is a field, method, or constructor
873 StringBuilder buf = new StringBuilder();
874 if (getDeclaringClass() != null) {
875 buf.append(getName(clazz));
876 buf.append('.');
877 }
878 String name = this.name; // avoid expanding from VM
879 buf.append(name == null ? "*" : name);
880 Object type = this.type; // avoid expanding from VM
881 if (!isInvocable()) {
882 buf.append('/');
883 buf.append(type == null ? "*" : getName(type));
884 } else {
885 buf.append(type == null ? "(*)*" : getName(type));
886 }
887 byte refKind = getReferenceKind();
888 if (refKind != REF_NONE) {
889 buf.append('/');
890 buf.append(MethodHandleNatives.refKindName(refKind));
891 }
892 //buf.append("#").append(System.identityHashCode(this));
893 return buf.toString();
894 }
895 private static String getName(Object obj) {
896 if (obj instanceof Class<?>)
897 return ((Class<?>)obj).getName();
898 return String.valueOf(obj);
899 }
900
901 public IllegalAccessException makeAccessException(String message, Object from) {
902 message = message + ": " + this;
903 if (from != null) {
904 if (from == MethodHandles.publicLookup()) {
905 message += ", from public Lookup";
906 } else {
907 Module m;
908 Class<?> plc;
909 if (from instanceof MethodHandles.Lookup lookup) {
910 from = lookup.lookupClass();
911 m = lookup.lookupClass().getModule();
912 plc = lookup.previousLookupClass();
913 } else {
914 m = ((Class<?>)from).getModule();
915 plc = null;
916 }
917 message += ", from " + from + " (" + m + ")";
918 if (plc != null) {
919 message += ", previous lookup " +
920 plc.getName() + " (" + plc.getModule() + ")";
921 }
922 }
923 }
924 return new IllegalAccessException(message);
925 }
926 private String message() {
927 if (isResolved())
928 return "no access";
929 else if (isObjectConstructor())
930 return "no such constructor";
931 else if (isMethod())
932 return "no such method";
933 else
934 return "no such field";
935 }
936 public ReflectiveOperationException makeAccessException() {
937 String message = message() + ": " + this;
938 ReflectiveOperationException ex;
939 if (isResolved() || !(resolution instanceof NoSuchMethodError ||
940 resolution instanceof NoSuchFieldError))
941 ex = new IllegalAccessException(message);
942 else if (isObjectConstructor())
943 ex = new NoSuchMethodException(message);
944 else if (isMethod())
945 ex = new NoSuchMethodException(message);
946 else
947 ex = new NoSuchFieldException(message);
948 if (resolution instanceof Throwable)
949 ex.initCause((Throwable) resolution);
950 return ex;
951 }
952
953 /** Actually making a query requires an access check. */
954 /*non-public*/
955 static Factory getFactory() {
956 return Factory.INSTANCE;
957 }
958 /** A factory type for resolving member names with the help of the VM.
959 * TBD: Define access-safe public constructors for this factory.
960 */
961 /*non-public*/
962 static class Factory {
963 private Factory() { } // singleton pattern
964 static final Factory INSTANCE = new Factory();
965
966 /** Produce a resolved version of the given member.
967 * Super types are searched (for inherited members) if {@code searchSupers} is true.
968 * Access checking is performed on behalf of the given {@code lookupClass}.
969 * If lookup fails or access is not permitted, null is returned.
970 * Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
971 */
972 private MemberName resolve(byte refKind, MemberName ref, Class<?> lookupClass, int allowedModes,
973 boolean speculativeResolve) {
974 MemberName m = ref.clone(); // JVM will side-effect the ref
975 assert(refKind == m.getReferenceKind());
976 try {
977 // There are 4 entities in play here:
978 // * LC: lookupClass
979 // * REFC: symbolic reference class (MN.clazz before resolution);
980 // * DEFC: resolved method holder (MN.clazz after resolution);
981 // * PTYPES: parameter types (MN.type)
982 //
983 // What we care about when resolving a MemberName is consistency between DEFC and PTYPES.
984 // We do type alias (TA) checks on DEFC to ensure that. DEFC is not known until the JVM
985 // finishes the resolution, so do TA checks right after MHN.resolve() is over.
986 //
987 // All parameters passed by a caller are checked against MH type (PTYPES) on every invocation,
988 // so it is safe to call a MH from any context.
989 //
990 // REFC view on PTYPES doesn't matter, since it is used only as a starting point for resolution and doesn't
991 // participate in method selection.
992 m = MethodHandleNatives.resolve(m, lookupClass, allowedModes, speculativeResolve);
993 if (m == null && speculativeResolve) {
994 return null;
995 }
996 m.checkForTypeAlias(m.getDeclaringClass());
997 m.resolution = null;
998 } catch (ClassNotFoundException | LinkageError ex) {
999 // JVM reports that the "bytecode behavior" would get an error
1000 assert(!m.isResolved());
1001 m.resolution = ex;
1002 return m;
1003 }
1004 assert(m.referenceKindIsConsistent());
1005 m.initResolved(true);
1006 assert(m.vminfoIsConsistent());
1007 return m;
1008 }
1009 /** Produce a resolved version of the given member.
1010 * Super types are searched (for inherited members) if {@code searchSupers} is true.
1011 * Access checking is performed on behalf of the given {@code lookupClass}.
1012 * If lookup fails or access is not permitted, a {@linkplain ReflectiveOperationException} is thrown.
1013 * Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
1014 */
1015 public <NoSuchMemberException extends ReflectiveOperationException>
1016 MemberName resolveOrFail(byte refKind, MemberName m,
1017 Class<?> lookupClass, int allowedModes,
1018 Class<NoSuchMemberException> nsmClass)
1019 throws IllegalAccessException, NoSuchMemberException {
1020 assert lookupClass != null || allowedModes == LM_TRUSTED;
1021 MemberName result = resolve(refKind, m, lookupClass, allowedModes, false);
1022 if (result.isResolved())
1023 return result;
1024 ReflectiveOperationException ex = result.makeAccessException();
1025 if (ex instanceof IllegalAccessException) throw (IllegalAccessException) ex;
1026 throw nsmClass.cast(ex);
1027 }
1028 /** Produce a resolved version of the given member.
1029 * Super types are searched (for inherited members) if {@code searchSupers} is true.
1030 * Access checking is performed on behalf of the given {@code lookupClass}.
1031 * If lookup fails or access is not permitted, return null.
1032 * Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
1033 */
1034 public MemberName resolveOrNull(byte refKind, MemberName m, Class<?> lookupClass, int allowedModes) {
1035 assert lookupClass != null || allowedModes == LM_TRUSTED;
1036 MemberName result = resolve(refKind, m, lookupClass, allowedModes, true);
1037 if (result != null && result.isResolved())
1038 return result;
1039 return null;
1040 }
1041 }
1042 }