1 /*
2 * Copyright (c) 2008, 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.lang.invoke;
27
28 import sun.invoke.util.BytecodeDescriptor;
29 import sun.invoke.util.VerifyAccess;
30
31 import java.lang.reflect.Constructor;
32 import java.lang.reflect.Field;
33 import java.lang.reflect.Member;
34 import java.lang.reflect.Method;
35 import java.lang.reflect.Modifier;
36 import java.util.ArrayList;
37 import java.util.Collections;
38 import java.util.Iterator;
39 import java.util.List;
40 import java.util.Objects;
41
42 import static java.lang.invoke.MethodHandleNatives.Constants.*;
43 import static java.lang.invoke.MethodHandleStatics.newIllegalArgumentException;
44 import static java.lang.invoke.MethodHandleStatics.newInternalError;
45
46 /**
47 * A {@code MemberName} is a compact symbolic datum which fully characterizes
48 * a method or field reference.
49 * A member name refers to a field, method, constructor, or member type.
50 * Every member name has a simple name (a string) and a type (either a Class or MethodType).
51 * A member name may also have a non-null declaring class, or it may be simply
52 * a naked name/type pair.
53 * A member name may also have non-zero modifier flags.
54 * Finally, a member name may be either resolved or unresolved.
55 * If it is resolved, the existence of the named member has been determined by the JVM.
56 * <p>
57 * Whether resolved or not, a member name provides no access rights or
58 * invocation capability to its possessor. It is merely a compact
59 * representation of all symbolic information necessary to link to
60 * and properly use the named member.
61 * <p>
62 * When resolved, a member name's internal implementation may include references to JVM metadata.
63 * This representation is stateless and only descriptive.
64 * It provides no private information and no capability to use the member.
65 * <p>
66 * By contrast, a {@linkplain java.lang.reflect.Method} contains fuller information
67 * about the internals of a method (except its bytecodes) and also
68 * allows invocation. A MemberName is much lighter than a Method,
69 * since it contains about 7 fields to the 16 of Method (plus its sub-arrays),
70 * and those seven fields omit much of the information in Method.
71 * @author jrose
72 */
73 /*non-public*/ final class ResolvedMethodName {
74 //@Injected JVM_Method* vmtarget;
75 //@Injected Class<?> vmholder;
76 };
77
78 /*non-public*/ final class MemberName implements Member, Cloneable {
79 private Class<?> clazz; // class in which the member is defined
80 private String name; // may be null if not yet materialized
81 private Object type; // may be null if not yet materialized
82 private int flags; // modifier bits; see reflect.Modifier
83 private ResolvedMethodName method; // cached resolved method information
84 //@Injected intptr_t vmindex; // vtable index or offset of resolved member
85 Object resolution; // if null, this guy is resolved
86
87 /** Return the declaring class of this member.
88 * In the case of a bare name and type, the declaring class will be null.
89 */
90 public Class<?> getDeclaringClass() {
91 return clazz;
92 }
93
94 /** Utility method producing the class loader of the declaring class. */
95 public ClassLoader getClassLoader() {
96 return clazz.getClassLoader();
97 }
98
99 /** Return the simple name of this member.
100 * For a type, it is the same as {@link Class#getSimpleName}.
101 * For a method or field, it is the simple name of the member.
102 * For a constructor, it is always {@code "<init>"}.
103 */
104 public String getName() {
105 if (name == null) {
106 expandFromVM();
107 if (name == null) {
108 return null;
109 }
110 }
111 return name;
112 }
113
114 public MethodType getMethodOrFieldType() {
115 if (isInvocable())
116 return getMethodType();
117 if (isGetter())
118 return MethodType.methodType(getFieldType());
119 if (isSetter())
120 return MethodType.methodType(void.class, getFieldType());
121 throw new InternalError("not a method or field: "+this);
122 }
123
124 /** Return the declared type of this member, which
125 * must be a method or constructor.
126 */
127 public MethodType getMethodType() {
128 if (type == null) {
129 expandFromVM();
130 if (type == null) {
131 return null;
132 }
133 }
134 if (!isInvocable()) {
135 throw newIllegalArgumentException("not invocable, no method type");
136 }
137
138 {
139 // Get a snapshot of type which doesn't get changed by racing threads.
140 final Object type = this.type;
141 if (type instanceof MethodType) {
142 return (MethodType) type;
143 }
144 }
145
146 // type is not a MethodType yet. Convert it thread-safely.
147 synchronized (this) {
148 if (type instanceof String) {
149 String sig = (String) type;
150 MethodType res = MethodType.fromDescriptor(sig, getClassLoader());
151 type = res;
152 } else if (type instanceof Object[]) {
153 Object[] typeInfo = (Object[]) type;
154 Class<?>[] ptypes = (Class<?>[]) typeInfo[1];
155 Class<?> rtype = (Class<?>) typeInfo[0];
156 MethodType res = MethodType.makeImpl(rtype, ptypes, true);
157 type = res;
158 }
159 // Make sure type is a MethodType for racing threads.
160 assert type instanceof MethodType : "bad method type " + type;
161 }
162 return (MethodType) type;
163 }
164
165 /** Return the descriptor of this member, which
166 * must be a method or constructor.
167 */
168 String getMethodDescriptor() {
169 if (type == null) {
170 expandFromVM();
171 if (type == null) {
172 return null;
173 }
174 }
175 if (!isInvocable()) {
176 throw newIllegalArgumentException("not invocable, no method type");
177 }
178
179 // Get a snapshot of type which doesn't get changed by racing threads.
180 final Object type = this.type;
181 if (type instanceof String) {
182 return (String) type;
183 } else {
184 return getMethodType().toMethodDescriptorString();
185 }
186 }
187
188 /** Return the actual type under which this method or constructor must be invoked.
189 * For non-static methods or constructors, this is the type with a leading parameter,
190 * a reference to declaring class. For static methods, it is the same as the declared type.
191 */
192 public MethodType getInvocationType() {
193 MethodType itype = getMethodOrFieldType();
194 Class<?> c = clazz.isValue() ? clazz.asValueType() : clazz;
195 if (isConstructor() && getReferenceKind() == REF_newInvokeSpecial)
196 return itype.changeReturnType(c);
197 if (!isStatic())
198 return itype.insertParameterTypes(0, c);
199 return itype;
200 }
201
202 /** Utility method producing the parameter types of the method type. */
203 public Class<?>[] getParameterTypes() {
204 return getMethodType().parameterArray();
205 }
206
207 /** Utility method producing the return type of the method type. */
208 public Class<?> getReturnType() {
209 return getMethodType().returnType();
210 }
211
212 /** Return the declared type of this member, which
213 * must be a field or type.
214 * If it is a type member, that type itself is returned.
215 */
216 public Class<?> getFieldType() {
217 if (type == null) {
218 expandFromVM();
219 if (type == null) {
220 return null;
221 }
222 }
223 if (isInvocable()) {
224 throw newIllegalArgumentException("not a field or nested class, no simple type");
225 }
226
227 {
228 // Get a snapshot of type which doesn't get changed by racing threads.
229 final Object type = this.type;
230 if (type instanceof Class<?>) {
231 return (Class<?>) type;
232 }
233 }
234
235 // type is not a Class yet. Convert it thread-safely.
236 synchronized (this) {
237 if (type instanceof String) {
238 String sig = (String) type;
239 MethodType mtype = MethodType.fromDescriptor("()"+sig, getClassLoader());
240 Class<?> res = mtype.returnType();
241 type = res;
242 }
243 // Make sure type is a Class for racing threads.
244 assert type instanceof Class<?> : "bad field type " + type;
245 }
246 return (Class<?>) type;
247 }
248
249 /** Utility method to produce either the method type or field type of this member. */
250 public Object getType() {
251 return (isInvocable() ? getMethodType() : getFieldType());
252 }
253
254 /** Utility method to produce the signature of this member,
255 * used within the class file format to describe its type.
256 */
257 public String getSignature() {
258 if (type == null) {
259 expandFromVM();
260 if (type == null) {
261 return null;
262 }
263 }
264 if (isInvocable())
265 return BytecodeDescriptor.unparse(getMethodType());
266 else
267 return BytecodeDescriptor.unparse(getFieldType());
268 }
269
270 /** Return the modifier flags of this member.
271 * @see java.lang.reflect.Modifier
272 */
273 public int getModifiers() {
274 return (flags & RECOGNIZED_MODIFIERS);
275 }
276
277 /** Return the reference kind of this member, or zero if none.
278 */
279 public byte getReferenceKind() {
280 return (byte) ((flags >>> MN_REFERENCE_KIND_SHIFT) & MN_REFERENCE_KIND_MASK);
281 }
282 private boolean referenceKindIsConsistent() {
283 byte refKind = getReferenceKind();
284 if (refKind == REF_NONE) return isType();
285 if (isField()) {
286 assert(staticIsConsistent());
287 assert(MethodHandleNatives.refKindIsField(refKind));
288 } else if (isConstructor()) {
289 assert(refKind == REF_newInvokeSpecial || refKind == REF_invokeSpecial);
290 } else if (isMethod()) {
291 assert(staticIsConsistent());
292 assert(MethodHandleNatives.refKindIsMethod(refKind));
293 if (clazz.isInterface())
294 assert(refKind == REF_invokeInterface ||
295 refKind == REF_invokeStatic ||
296 refKind == REF_invokeSpecial ||
297 refKind == REF_invokeVirtual && isObjectPublicMethod());
298 } else {
299 assert(false);
300 }
301 return true;
302 }
303 private boolean isObjectPublicMethod() {
304 if (clazz == Object.class) return true;
305 MethodType mtype = getMethodType();
306 if (name.equals("toString") && mtype.returnType() == String.class && mtype.parameterCount() == 0)
307 return true;
308 if (name.equals("hashCode") && mtype.returnType() == int.class && mtype.parameterCount() == 0)
309 return true;
310 if (name.equals("equals") && mtype.returnType() == boolean.class && mtype.parameterCount() == 1 && mtype.parameterType(0) == Object.class)
311 return true;
312 return false;
313 }
314 /*non-public*/ boolean referenceKindIsConsistentWith(int originalRefKind) {
315 int refKind = getReferenceKind();
316 if (refKind == originalRefKind) return true;
317 switch (originalRefKind) {
318 case REF_invokeInterface:
319 // Looking up an interface method, can get (e.g.) Object.hashCode
320 assert(refKind == REF_invokeVirtual ||
321 refKind == REF_invokeSpecial) : this;
322 return true;
323 case REF_invokeVirtual:
324 case REF_newInvokeSpecial:
325 // Looked up a virtual, can get (e.g.) final String.hashCode.
326 assert(refKind == REF_invokeSpecial) : this;
327 return true;
328 }
329 assert(false) : this+" != "+MethodHandleNatives.refKindName((byte)originalRefKind);
330 return true;
331 }
332 private boolean staticIsConsistent() {
333 byte refKind = getReferenceKind();
334 return MethodHandleNatives.refKindIsStatic(refKind) == isStatic() || getModifiers() == 0;
335 }
336 private boolean vminfoIsConsistent() {
337 byte refKind = getReferenceKind();
338 assert(isResolved()); // else don't call
339 Object vminfo = MethodHandleNatives.getMemberVMInfo(this);
340 assert(vminfo instanceof Object[]);
341 long vmindex = (Long) ((Object[])vminfo)[0];
342 Object vmtarget = ((Object[])vminfo)[1];
343 if (MethodHandleNatives.refKindIsField(refKind)) {
344 assert(vmindex >= 0) : vmindex + ":" + this;
345 assert(vmtarget instanceof Class);
346 } else {
347 if (MethodHandleNatives.refKindDoesDispatch(refKind))
348 assert(vmindex >= 0) : vmindex + ":" + this;
349 else
350 assert(vmindex < 0) : vmindex;
351 assert(vmtarget instanceof MemberName) : vmtarget + " in " + this;
352 }
353 return true;
354 }
355
356 private MemberName changeReferenceKind(byte refKind, byte oldKind) {
357 assert(getReferenceKind() == oldKind);
358 assert(MethodHandleNatives.refKindIsValid(refKind));
359 flags += (((int)refKind - oldKind) << MN_REFERENCE_KIND_SHIFT);
360 return this;
361 }
362
363 private boolean testFlags(int mask, int value) {
364 return (flags & mask) == value;
365 }
366 private boolean testAllFlags(int mask) {
367 return testFlags(mask, mask);
368 }
369 private boolean testAnyFlags(int mask) {
370 return !testFlags(mask, 0);
371 }
372
373 /** Utility method to query if this member is a method handle invocation (invoke or invokeExact).
374 */
375 public boolean isMethodHandleInvoke() {
376 final int bits = MH_INVOKE_MODS &~ Modifier.PUBLIC;
377 final int negs = Modifier.STATIC;
378 if (testFlags(bits | negs, bits) &&
379 clazz == MethodHandle.class) {
380 return isMethodHandleInvokeName(name);
381 }
382 return false;
383 }
384 public static boolean isMethodHandleInvokeName(String name) {
385 switch (name) {
386 case "invoke":
387 case "invokeExact":
388 return true;
389 default:
390 return false;
391 }
392 }
393 public boolean isVarHandleMethodInvoke() {
394 final int bits = MH_INVOKE_MODS &~ Modifier.PUBLIC;
395 final int negs = Modifier.STATIC;
396 if (testFlags(bits | negs, bits) &&
397 clazz == VarHandle.class) {
398 return isVarHandleMethodInvokeName(name);
399 }
400 return false;
401 }
402 public static boolean isVarHandleMethodInvokeName(String name) {
403 try {
404 VarHandle.AccessMode.valueFromMethodName(name);
405 return true;
406 } catch (IllegalArgumentException e) {
407 return false;
408 }
409 }
410 private static final int MH_INVOKE_MODS = Modifier.NATIVE | Modifier.FINAL | Modifier.PUBLIC;
411
412 /** Utility method to query the modifier flags of this member. */
413 public boolean isStatic() {
414 return Modifier.isStatic(flags);
415 }
416 /** Utility method to query the modifier flags of this member. */
417 public boolean isPublic() {
418 return Modifier.isPublic(flags);
419 }
420 /** Utility method to query the modifier flags of this member. */
421 public boolean isPrivate() {
422 return Modifier.isPrivate(flags);
423 }
424 /** Utility method to query the modifier flags of this member. */
425 public boolean isProtected() {
426 return Modifier.isProtected(flags);
427 }
428 /** Utility method to query the modifier flags of this member. */
429 public boolean isFinal() {
430 // all fields declared in a value type are effectively final
431 assert(!clazz.isValue() || !isField() || Modifier.isFinal(flags));
432 return Modifier.isFinal(flags);
433 }
434 /** Utility method to query whether this member or its defining class is final. */
435 public boolean canBeStaticallyBound() {
436 return Modifier.isFinal(flags | clazz.getModifiers());
437 }
438 /** Utility method to query the modifier flags of this member. */
439 public boolean isVolatile() {
440 return Modifier.isVolatile(flags);
441 }
442 /** Utility method to query the modifier flags of this member. */
443 public boolean isAbstract() {
444 return Modifier.isAbstract(flags);
445 }
446 /** Utility method to query the modifier flags of this member. */
447 public boolean isNative() {
448 return Modifier.isNative(flags);
449 }
450 // let the rest (native, volatile, transient, etc.) be tested via Modifier.isFoo
451
452 // unofficial modifier flags, used by HotSpot:
453 static final int BRIDGE = 0x00000040;
454 static final int VARARGS = 0x00000080;
455 static final int SYNTHETIC = 0x00001000;
456 static final int ANNOTATION = 0x00002000;
457 static final int ENUM = 0x00004000;
458 static final int FLATTENABLE = 0x00000100;
459 static final int FLATTENED = 0x00008000;
460
461 /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
462 public boolean isBridge() {
463 return testAllFlags(IS_METHOD | BRIDGE);
464 }
465 /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
466 public boolean isVarargs() {
467 return testAllFlags(VARARGS) && isInvocable();
468 }
469 /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
470 public boolean isSynthetic() {
471 return testAllFlags(SYNTHETIC);
472 }
473
474 /*
475 * Query whether this member is a flattenable field.
476 *
477 * A flattenable field whose type must be of value class with ACC_FLATTENABLE flag set.
478 * A field of value type may or may not be flattenable.
479 */
480 public boolean isFlattenable() { return (flags & FLATTENABLE) == FLATTENABLE; }
481
482 /** Query whether this member is a flat value field */
483 public boolean isFlatValue() { return (flags & FLATTENED) == FLATTENED; }
484
485 /** Query whether this member can be assigned to null. */
486 public boolean canBeNull() { return !isFlattenable(); }
487
488 static final String CONSTRUCTOR_NAME = "<init>"; // the ever-popular
489
490 // modifiers exported by the JVM:
491 static final int RECOGNIZED_MODIFIERS = 0xFFFF;
492
493 // private flags, not part of RECOGNIZED_MODIFIERS:
494 static final int
495 IS_METHOD = MN_IS_METHOD, // method (not constructor)
496 IS_CONSTRUCTOR = MN_IS_CONSTRUCTOR, // constructor
497 IS_FIELD = MN_IS_FIELD, // field
498 IS_TYPE = MN_IS_TYPE, // nested type
499 CALLER_SENSITIVE = MN_CALLER_SENSITIVE; // @CallerSensitive annotation detected
500
501 static final int ALL_ACCESS = Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED;
502 static final int ALL_KINDS = IS_METHOD | IS_CONSTRUCTOR | IS_FIELD | IS_TYPE;
503 static final int IS_INVOCABLE = IS_METHOD | IS_CONSTRUCTOR;
504 static final int IS_FIELD_OR_METHOD = IS_METHOD | IS_FIELD;
505 static final int SEARCH_ALL_SUPERS = MN_SEARCH_SUPERCLASSES | MN_SEARCH_INTERFACES;
506
507 /** Utility method to query whether this member is a method or constructor. */
508 public boolean isInvocable() {
509 return testAnyFlags(IS_INVOCABLE);
510 }
511 /** Utility method to query whether this member is a method, constructor, or field. */
512 public boolean isFieldOrMethod() {
513 return testAnyFlags(IS_FIELD_OR_METHOD);
514 }
515 /** Query whether this member is a method. */
516 public boolean isMethod() {
517 return testAllFlags(IS_METHOD);
518 }
519 /** Query whether this member is a constructor. */
520 public boolean isConstructor() {
521 return testAllFlags(IS_CONSTRUCTOR);
522 }
523 /** Query whether this member is a field. */
524 public boolean isField() {
525 return testAllFlags(IS_FIELD);
526 }
527 /** Query whether this member is a type. */
528 public boolean isType() {
529 return testAllFlags(IS_TYPE);
530 }
531 /** Utility method to query whether this member is neither public, private, nor protected. */
532 public boolean isPackage() {
533 return !testAnyFlags(ALL_ACCESS);
534 }
535 /** Query whether this member has a CallerSensitive annotation. */
536 public boolean isCallerSensitive() {
537 return testAllFlags(CALLER_SENSITIVE);
538 }
539
540 /** Utility method to query whether this member is accessible from a given lookup class. */
541 public boolean isAccessibleFrom(Class<?> lookupClass) {
542 int mode = (ALL_ACCESS|MethodHandles.Lookup.PACKAGE|MethodHandles.Lookup.MODULE);
543 return VerifyAccess.isMemberAccessible(this.getDeclaringClass(), this.getDeclaringClass(), flags,
544 lookupClass, mode);
545 }
546
547 /**
548 * Check if MemberName is a call to a method named {@code name} in class {@code declaredClass}.
549 */
550 public boolean refersTo(Class<?> declc, String n) {
551 return clazz == declc && getName().equals(n);
552 }
553
554 /** Initialize a query. It is not resolved. */
555 private void init(Class<?> defClass, String name, Object type, int flags) {
556 // defining class is allowed to be null (for a naked name/type pair)
557 //name.toString(); // null check
558 //type.equals(type); // null check
559 // fill in fields:
560 this.clazz = defClass;
561 this.name = name;
562 this.type = type;
563 this.flags = flags;
564 assert(testAnyFlags(ALL_KINDS));
565 assert(this.resolution == null); // nobody should have touched this yet
566 //assert(referenceKindIsConsistent()); // do this after resolution
567 }
568
569 /**
570 * Calls down to the VM to fill in the fields. This method is
571 * synchronized to avoid racing calls.
572 */
573 private void expandFromVM() {
574 if (type != null) {
575 return;
576 }
577 if (!isResolved()) {
578 return;
579 }
580 MethodHandleNatives.expand(this);
581 }
582
583 // Capturing information from the Core Reflection API:
584 private static int flagsMods(int flags, int mods, byte refKind) {
585 assert((flags & RECOGNIZED_MODIFIERS) == 0);
586 assert((mods & ~RECOGNIZED_MODIFIERS) == 0);
587 assert((refKind & ~MN_REFERENCE_KIND_MASK) == 0);
588 return flags | mods | (refKind << MN_REFERENCE_KIND_SHIFT);
589 }
590 /** Create a name for the given reflected method. The resulting name will be in a resolved state. */
591 public MemberName(Method m) {
592 this(m, false);
593 }
594 @SuppressWarnings("LeakingThisInConstructor")
595 public MemberName(Method m, boolean wantSpecial) {
596 Objects.requireNonNull(m);
597 // fill in vmtarget, vmindex while we have m in hand:
598 MethodHandleNatives.init(this, m);
599 if (clazz == null) { // MHN.init failed
600 if (m.getDeclaringClass() == MethodHandle.class &&
601 isMethodHandleInvokeName(m.getName())) {
602 // The JVM did not reify this signature-polymorphic instance.
603 // Need a special case here.
604 // See comments on MethodHandleNatives.linkMethod.
605 MethodType type = MethodType.methodType(m.getReturnType(), m.getParameterTypes());
606 int flags = flagsMods(IS_METHOD, m.getModifiers(), REF_invokeVirtual);
607 init(MethodHandle.class, m.getName(), type, flags);
608 if (isMethodHandleInvoke())
609 return;
610 }
611 if (m.getDeclaringClass() == VarHandle.class &&
612 isVarHandleMethodInvokeName(m.getName())) {
613 // The JVM did not reify this signature-polymorphic instance.
614 // Need a special case here.
615 // See comments on MethodHandleNatives.linkMethod.
616 MethodType type = MethodType.methodType(m.getReturnType(), m.getParameterTypes());
617 int flags = flagsMods(IS_METHOD, m.getModifiers(), REF_invokeVirtual);
618 init(VarHandle.class, m.getName(), type, flags);
619 if (isVarHandleMethodInvoke())
620 return;
621 }
622 throw new LinkageError(m.toString());
623 }
624 assert(isResolved() && this.clazz != null);
625 this.name = m.getName();
626 if (this.type == null)
627 this.type = new Object[] { m.getReturnType(), m.getParameterTypes() };
628 if (wantSpecial) {
629 if (isAbstract())
630 throw new AbstractMethodError(this.toString());
631 if (getReferenceKind() == REF_invokeVirtual)
632 changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual);
633 else if (getReferenceKind() == REF_invokeInterface)
634 // invokeSpecial on a default method
635 changeReferenceKind(REF_invokeSpecial, REF_invokeInterface);
636 }
637 }
638 public MemberName asSpecial() {
639 switch (getReferenceKind()) {
640 case REF_invokeSpecial: return this;
641 case REF_invokeVirtual: return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual);
642 case REF_invokeInterface: return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeInterface);
643 case REF_newInvokeSpecial: return clone().changeReferenceKind(REF_invokeSpecial, REF_newInvokeSpecial);
644 }
645 throw new IllegalArgumentException(this.toString());
646 }
647 /** If this MN is not REF_newInvokeSpecial, return a clone with that ref. kind.
648 * In that case it must already be REF_invokeSpecial.
649 */
650 public MemberName asConstructor() {
651 switch (getReferenceKind()) {
652 case REF_invokeSpecial: return clone().changeReferenceKind(REF_newInvokeSpecial, REF_invokeSpecial);
653 case REF_newInvokeSpecial: return this;
654 }
655 throw new IllegalArgumentException(this.toString());
656 }
657 /** If this MN is a REF_invokeSpecial, return a clone with the "normal" kind
658 * REF_invokeVirtual; also switch either to REF_invokeInterface if clazz.isInterface.
659 * The end result is to get a fully virtualized version of the MN.
660 * (Note that resolving in the JVM will sometimes devirtualize, changing
661 * REF_invokeVirtual of a final to REF_invokeSpecial, and REF_invokeInterface
662 * in some corner cases to either of the previous two; this transform
663 * undoes that change under the assumption that it occurred.)
664 */
665 public MemberName asNormalOriginal() {
666 byte normalVirtual = clazz.isInterface() ? REF_invokeInterface : REF_invokeVirtual;
667 byte refKind = getReferenceKind();
668 byte newRefKind = refKind;
669 MemberName result = this;
670 switch (refKind) {
671 case REF_invokeInterface:
672 case REF_invokeVirtual:
673 case REF_invokeSpecial:
674 newRefKind = normalVirtual;
675 break;
676 }
677 if (newRefKind == refKind)
678 return this;
679 result = clone().changeReferenceKind(newRefKind, refKind);
680 assert(this.referenceKindIsConsistentWith(result.getReferenceKind()));
681 return result;
682 }
683 /** Create a name for the given reflected constructor. The resulting name will be in a resolved state. */
684 @SuppressWarnings("LeakingThisInConstructor")
685 public MemberName(Constructor<?> ctor) {
686 Objects.requireNonNull(ctor);
687 // fill in vmtarget, vmindex while we have ctor in hand:
688 MethodHandleNatives.init(this, ctor);
689 assert(isResolved() && this.clazz != null);
690 this.name = CONSTRUCTOR_NAME;
691 if (this.type == null)
692 this.type = new Object[] { void.class, ctor.getParameterTypes() };
693 }
694 /** Create a name for the given reflected field. The resulting name will be in a resolved state.
695 */
696 public MemberName(Field fld) {
697 this(fld, false);
698 }
699 @SuppressWarnings("LeakingThisInConstructor")
700 public MemberName(Field fld, boolean makeSetter) {
701 Objects.requireNonNull(fld);
702 // fill in vmtarget, vmindex while we have fld in hand:
703 MethodHandleNatives.init(this, fld);
704 assert(isResolved() && this.clazz != null);
705 this.name = fld.getName();
706 this.type = fld.getType();
707 assert((REF_putStatic - REF_getStatic) == (REF_putField - REF_getField));
708 byte refKind = this.getReferenceKind();
709 assert(refKind == (isStatic() ? REF_getStatic : REF_getField));
710 if (makeSetter) {
711 changeReferenceKind((byte)(refKind + (REF_putStatic - REF_getStatic)), refKind);
712 }
713 }
714 public boolean isGetter() {
715 return MethodHandleNatives.refKindIsGetter(getReferenceKind());
716 }
717 public boolean isSetter() {
718 return MethodHandleNatives.refKindIsSetter(getReferenceKind());
719 }
720 public MemberName asSetter() {
721 byte refKind = getReferenceKind();
722 assert(MethodHandleNatives.refKindIsGetter(refKind));
723 assert((REF_putStatic - REF_getStatic) == (REF_putField - REF_getField));
724 byte setterRefKind = (byte)(refKind + (REF_putField - REF_getField));
725 return clone().changeReferenceKind(setterRefKind, refKind);
726 }
727 /** Create a name for the given class. The resulting name will be in a resolved state. */
728 public MemberName(Class<?> type) {
729 init(type.getDeclaringClass(), type.getSimpleName(), type,
730 flagsMods(IS_TYPE, type.getModifiers(), REF_NONE));
731 initResolved(true);
732 }
733
734 /**
735 * Create a name for a signature-polymorphic invoker.
736 * This is a placeholder for a signature-polymorphic instance
737 * (of MH.invokeExact, etc.) that the JVM does not reify.
738 * See comments on {@link MethodHandleNatives#linkMethod}.
739 */
740 static MemberName makeMethodHandleInvoke(String name, MethodType type) {
741 return makeMethodHandleInvoke(name, type, MH_INVOKE_MODS | SYNTHETIC);
742 }
743 static MemberName makeMethodHandleInvoke(String name, MethodType type, int mods) {
744 MemberName mem = new MemberName(MethodHandle.class, name, type, REF_invokeVirtual);
745 mem.flags |= mods; // it's not resolved, but add these modifiers anyway
746 assert(mem.isMethodHandleInvoke()) : mem;
747 return mem;
748 }
749
750 static MemberName makeVarHandleMethodInvoke(String name, MethodType type) {
751 return makeVarHandleMethodInvoke(name, type, MH_INVOKE_MODS | SYNTHETIC);
752 }
753 static MemberName makeVarHandleMethodInvoke(String name, MethodType type, int mods) {
754 MemberName mem = new MemberName(VarHandle.class, name, type, REF_invokeVirtual);
755 mem.flags |= mods; // it's not resolved, but add these modifiers anyway
756 assert(mem.isVarHandleMethodInvoke()) : mem;
757 return mem;
758 }
759
760 // bare-bones constructor; the JVM will fill it in
761 MemberName() { }
762
763 // locally useful cloner
764 @Override protected MemberName clone() {
765 try {
766 return (MemberName) super.clone();
767 } catch (CloneNotSupportedException ex) {
768 throw newInternalError(ex);
769 }
770 }
771
772 /** Get the definition of this member name.
773 * This may be in a super-class of the declaring class of this member.
774 */
775 public MemberName getDefinition() {
776 if (!isResolved()) throw new IllegalStateException("must be resolved: "+this);
777 if (isType()) return this;
778 MemberName res = this.clone();
779 res.clazz = null;
780 res.type = null;
781 res.name = null;
782 res.resolution = res;
783 res.expandFromVM();
784 assert(res.getName().equals(this.getName()));
785 return res;
786 }
787
788 @Override
789 @SuppressWarnings("deprecation")
790 public int hashCode() {
791 // Avoid autoboxing getReferenceKind(), since this is used early and will force
792 // early initialization of Byte$ByteCache
793 return Objects.hash(clazz, new Byte(getReferenceKind()), name, getType());
794 }
795
796 @Override
797 public boolean equals(Object that) {
798 return (that instanceof MemberName && this.equals((MemberName)that));
799 }
800
801 /** Decide if two member names have exactly the same symbolic content.
802 * Does not take into account any actual class members, so even if
803 * two member names resolve to the same actual member, they may
804 * be distinct references.
805 */
806 public boolean equals(MemberName that) {
807 if (this == that) return true;
808 if (that == null) return false;
809 return this.clazz == that.clazz
810 && this.getReferenceKind() == that.getReferenceKind()
811 && Objects.equals(this.name, that.name)
812 && Objects.equals(this.getType(), that.getType());
813 }
814
815 // Construction from symbolic parts, for queries:
816 /** Create a field or type name from the given components:
817 * Declaring class, name, type, reference kind.
818 * The declaring class may be supplied as null if this is to be a bare name and type.
819 * The resulting name will in an unresolved state.
820 */
821 public MemberName(Class<?> defClass, String name, Class<?> type, byte refKind) {
822 init(defClass, name, type, flagsMods(IS_FIELD, 0, refKind));
823 initResolved(false);
824 }
825 /** Create a method or constructor name from the given components:
826 * Declaring class, name, type, reference kind.
827 * It will be a constructor if and only if the name is {@code "<init>"}.
828 * The declaring class may be supplied as null if this is to be a bare name and type.
829 * The last argument is optional, a boolean which requests REF_invokeSpecial.
830 * The resulting name will in an unresolved state.
831 */
832 public MemberName(Class<?> defClass, String name, MethodType type, byte refKind) {
833 int initFlags = (name != null && name.equals(CONSTRUCTOR_NAME) ? IS_CONSTRUCTOR : IS_METHOD);
834 init(defClass, name, type, flagsMods(initFlags, 0, refKind));
835 initResolved(false);
836 }
837 /** Create a method, constructor, or field name from the given components:
838 * Reference kind, declaring class, name, type.
839 */
840 public MemberName(byte refKind, Class<?> defClass, String name, Object type) {
841 int kindFlags;
842 if (MethodHandleNatives.refKindIsField(refKind)) {
843 kindFlags = IS_FIELD;
844 if (!(type instanceof Class))
845 throw newIllegalArgumentException("not a field type");
846 } else if (MethodHandleNatives.refKindIsMethod(refKind)) {
847 kindFlags = IS_METHOD;
848 if (!(type instanceof MethodType))
849 throw newIllegalArgumentException("not a method type");
850 } else if (refKind == REF_newInvokeSpecial) {
851 kindFlags = IS_CONSTRUCTOR;
852 if (!(type instanceof MethodType) ||
853 !CONSTRUCTOR_NAME.equals(name))
854 throw newIllegalArgumentException("not a constructor type or name");
855 } else {
856 throw newIllegalArgumentException("bad reference kind "+refKind);
857 }
858 init(defClass, name, type, flagsMods(kindFlags, 0, refKind));
859 initResolved(false);
860 }
861 /** Query whether this member name is resolved to a non-static, non-final method.
862 */
863 public boolean hasReceiverTypeDispatch() {
864 return MethodHandleNatives.refKindDoesDispatch(getReferenceKind());
865 }
866
867 /** Query whether this member name is resolved.
868 * A resolved member name is one for which the JVM has found
869 * a method, constructor, field, or type binding corresponding exactly to the name.
870 * (Document?)
871 */
872 public boolean isResolved() {
873 return resolution == null;
874 }
875
876 void initResolved(boolean isResolved) {
877 assert(this.resolution == null); // not initialized yet!
878 if (!isResolved)
879 this.resolution = this;
880 assert(isResolved() == isResolved);
881 }
882
883 void checkForTypeAlias(Class<?> refc) {
884 if (isInvocable()) {
885 MethodType type;
886 if (this.type instanceof MethodType)
887 type = (MethodType) this.type;
888 else
889 this.type = type = getMethodType();
890 if (type.erase() == type) return;
891 if (VerifyAccess.isTypeVisible(type, refc)) return;
892 throw new LinkageError("bad method type alias: "+type+" not visible from "+refc);
893 } else {
894 Class<?> type;
895 if (this.type instanceof Class<?>)
896 type = (Class<?>) this.type;
897 else
898 this.type = type = getFieldType();
899 if (VerifyAccess.isTypeVisible(type, refc)) return;
900 throw new LinkageError("bad field type alias: "+type+" not visible from "+refc);
901 }
902 }
903
904
905 /** Produce a string form of this member name.
906 * For types, it is simply the type's own string (as reported by {@code toString}).
907 * For fields, it is {@code "DeclaringClass.name/type"}.
908 * For methods and constructors, it is {@code "DeclaringClass.name(ptype...)rtype"}.
909 * If the declaring class is null, the prefix {@code "DeclaringClass."} is omitted.
910 * If the member is unresolved, a prefix {@code "*."} is prepended.
911 */
912 @SuppressWarnings("LocalVariableHidesMemberVariable")
913 @Override
914 public String toString() {
915 if (isType())
916 return type.toString(); // class java.lang.String
917 // else it is a field, method, or constructor
918 StringBuilder buf = new StringBuilder();
919 if (getDeclaringClass() != null) {
920 buf.append(getName(clazz));
921 buf.append('.');
922 }
923 String name = this.name; // avoid expanding from VM
924 buf.append(name == null ? "*" : name);
925 Object type = this.type; // avoid expanding from VM
926 if (!isInvocable()) {
927 buf.append('/');
928 buf.append(type == null ? "*" : getName(type));
929 } else {
930 buf.append(type == null ? "(*)*" : getName(type));
931 }
932 byte refKind = getReferenceKind();
933 if (refKind != REF_NONE) {
934 buf.append('/');
935 buf.append(MethodHandleNatives.refKindName(refKind));
936 }
937 //buf.append("#").append(System.identityHashCode(this));
938 return buf.toString();
939 }
940 private static String getName(Object obj) {
941 if (obj instanceof Class<?>)
942 return ((Class<?>)obj).getName();
943 return String.valueOf(obj);
944 }
945
946 public IllegalAccessException makeAccessException(String message, Object from) {
947 message = message + ": "+ toString();
948 if (from != null) {
949 if (from == MethodHandles.publicLookup()) {
950 message += ", from public Lookup";
951 } else {
952 Module m;
953 if (from instanceof MethodHandles.Lookup) {
954 MethodHandles.Lookup lookup = (MethodHandles.Lookup)from;
955 m = lookup.lookupClass().getModule();
956 } else {
957 m = from.getClass().getModule();
958 }
959 message += ", from " + from + " (" + m + ")";
960 }
961 }
962 return new IllegalAccessException(message);
963 }
964 private String message() {
965 if (isResolved())
966 return "no access";
967 else if (isConstructor())
968 return "no such constructor";
969 else if (isMethod())
970 return "no such method";
971 else
972 return "no such field";
973 }
974 public ReflectiveOperationException makeAccessException() {
975 String message = message() + ": "+ toString();
976 ReflectiveOperationException ex;
977 if (isResolved() || !(resolution instanceof NoSuchMethodError ||
978 resolution instanceof NoSuchFieldError))
979 ex = new IllegalAccessException(message);
980 else if (isConstructor())
981 ex = new NoSuchMethodException(message);
982 else if (isMethod())
983 ex = new NoSuchMethodException(message);
984 else
985 ex = new NoSuchFieldException(message);
986 if (resolution instanceof Throwable)
987 ex.initCause((Throwable) resolution);
988 return ex;
989 }
990
991 /** Actually making a query requires an access check. */
992 /*non-public*/ static Factory getFactory() {
993 return Factory.INSTANCE;
994 }
995 /** A factory type for resolving member names with the help of the VM.
996 * TBD: Define access-safe public constructors for this factory.
997 */
998 /*non-public*/ static class Factory {
999 private Factory() { } // singleton pattern
1000 static Factory INSTANCE = new Factory();
1001
1002 private static int ALLOWED_FLAGS = ALL_KINDS;
1003
1004 /// Queries
1005 List<MemberName> getMembers(Class<?> defc,
1006 String matchName, Object matchType,
1007 int matchFlags, Class<?> lookupClass) {
1008 matchFlags &= ALLOWED_FLAGS;
1009 String matchSig = null;
1010 if (matchType != null) {
1011 matchSig = BytecodeDescriptor.unparse(matchType);
1012 if (matchSig.startsWith("("))
1013 matchFlags &= ~(ALL_KINDS & ~IS_INVOCABLE);
1014 else
1015 matchFlags &= ~(ALL_KINDS & ~IS_FIELD);
1016 }
1017 final int BUF_MAX = 0x2000;
1018 int len1 = matchName == null ? 10 : matchType == null ? 4 : 1;
1019 MemberName[] buf = newMemberBuffer(len1);
1020 int totalCount = 0;
1021 ArrayList<MemberName[]> bufs = null;
1022 int bufCount = 0;
1023 for (;;) {
1024 bufCount = MethodHandleNatives.getMembers(defc,
1025 matchName, matchSig, matchFlags,
1026 lookupClass,
1027 totalCount, buf);
1028 if (bufCount <= buf.length) {
1029 if (bufCount < 0) bufCount = 0;
1030 totalCount += bufCount;
1031 break;
1032 }
1033 // JVM returned to us with an intentional overflow!
1034 totalCount += buf.length;
1035 int excess = bufCount - buf.length;
1036 if (bufs == null) bufs = new ArrayList<>(1);
1037 bufs.add(buf);
1038 int len2 = buf.length;
1039 len2 = Math.max(len2, excess);
1040 len2 = Math.max(len2, totalCount / 4);
1041 buf = newMemberBuffer(Math.min(BUF_MAX, len2));
1042 }
1043 ArrayList<MemberName> result = new ArrayList<>(totalCount);
1044 if (bufs != null) {
1045 for (MemberName[] buf0 : bufs) {
1046 Collections.addAll(result, buf0);
1047 }
1048 }
1049 for (int i = 0; i < bufCount; i++) {
1050 result.add(buf[i]);
1051 }
1052 // Signature matching is not the same as type matching, since
1053 // one signature might correspond to several types.
1054 // So if matchType is a Class or MethodType, refilter the results.
1055 if (matchType != null && matchType != matchSig) {
1056 for (Iterator<MemberName> it = result.iterator(); it.hasNext();) {
1057 MemberName m = it.next();
1058 if (!matchType.equals(m.getType()))
1059 it.remove();
1060 }
1061 }
1062 return result;
1063 }
1064 /** Produce a resolved version of the given member.
1065 * Super types are searched (for inherited members) if {@code searchSupers} is true.
1066 * Access checking is performed on behalf of the given {@code lookupClass}.
1067 * If lookup fails or access is not permitted, null is returned.
1068 * Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
1069 */
1070 private MemberName resolve(byte refKind, MemberName ref, Class<?> lookupClass,
1071 boolean speculativeResolve) {
1072 MemberName m = ref.clone(); // JVM will side-effect the ref
1073 assert(refKind == m.getReferenceKind());
1074 try {
1075 // There are 4 entities in play here:
1076 // * LC: lookupClass
1077 // * REFC: symbolic reference class (MN.clazz before resolution);
1078 // * DEFC: resolved method holder (MN.clazz after resolution);
1079 // * PTYPES: parameter types (MN.type)
1080 //
1081 // What we care about when resolving a MemberName is consistency between DEFC and PTYPES.
1082 // We do type alias (TA) checks on DEFC to ensure that. DEFC is not known until the JVM
1083 // finishes the resolution, so do TA checks right after MHN.resolve() is over.
1084 //
1085 // All parameters passed by a caller are checked against MH type (PTYPES) on every invocation,
1086 // so it is safe to call a MH from any context.
1087 //
1088 // REFC view on PTYPES doesn't matter, since it is used only as a starting point for resolution and doesn't
1089 // participate in method selection.
1090 m = MethodHandleNatives.resolve(m, lookupClass, speculativeResolve);
1091 if (m == null && speculativeResolve) {
1092 return null;
1093 }
1094 m.checkForTypeAlias(m.getDeclaringClass());
1095 m.resolution = null;
1096 } catch (ClassNotFoundException | LinkageError ex) {
1097 // JVM reports that the "bytecode behavior" would get an error
1098 assert(!m.isResolved());
1099 m.resolution = ex;
1100 return m;
1101 }
1102 assert(m.referenceKindIsConsistent());
1103 m.initResolved(true);
1104 assert(m.vminfoIsConsistent());
1105 return m;
1106 }
1107 /** Produce a resolved version of the given member.
1108 * Super types are searched (for inherited members) if {@code searchSupers} is true.
1109 * Access checking is performed on behalf of the given {@code lookupClass}.
1110 * If lookup fails or access is not permitted, a {@linkplain ReflectiveOperationException} is thrown.
1111 * Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
1112 */
1113 public
1114 <NoSuchMemberException extends ReflectiveOperationException>
1115 MemberName resolveOrFail(byte refKind, MemberName m, Class<?> lookupClass,
1116 Class<NoSuchMemberException> nsmClass)
1117 throws IllegalAccessException, NoSuchMemberException {
1118 MemberName result = resolve(refKind, m, lookupClass, false);
1119 if (result.isResolved())
1120 return result;
1121 ReflectiveOperationException ex = result.makeAccessException();
1122 if (ex instanceof IllegalAccessException) throw (IllegalAccessException) ex;
1123 throw nsmClass.cast(ex);
1124 }
1125 /** Produce a resolved version of the given member.
1126 * Super types are searched (for inherited members) if {@code searchSupers} is true.
1127 * Access checking is performed on behalf of the given {@code lookupClass}.
1128 * If lookup fails or access is not permitted, return null.
1129 * Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
1130 */
1131 public
1132 MemberName resolveOrNull(byte refKind, MemberName m, Class<?> lookupClass) {
1133 MemberName result = resolve(refKind, m, lookupClass, true);
1134 if (result != null && result.isResolved())
1135 return result;
1136 return null;
1137 }
1138 /** Return a list of all methods defined by the given class.
1139 * Super types are searched (for inherited members) if {@code searchSupers} is true.
1140 * Access checking is performed on behalf of the given {@code lookupClass}.
1141 * Inaccessible members are not added to the last.
1142 */
1143 public List<MemberName> getMethods(Class<?> defc, boolean searchSupers,
1144 Class<?> lookupClass) {
1145 return getMethods(defc, searchSupers, null, null, lookupClass);
1146 }
1147 /** Return a list of matching methods defined by the given class.
1148 * Super types are searched (for inherited members) if {@code searchSupers} is true.
1149 * Returned methods will match the name (if not null) and the type (if not null).
1150 * Access checking is performed on behalf of the given {@code lookupClass}.
1151 * Inaccessible members are not added to the last.
1152 */
1153 public List<MemberName> getMethods(Class<?> defc, boolean searchSupers,
1154 String name, MethodType type, Class<?> lookupClass) {
1155 int matchFlags = IS_METHOD | (searchSupers ? SEARCH_ALL_SUPERS : 0);
1156 return getMembers(defc, name, type, matchFlags, lookupClass);
1157 }
1158 /** Return a list of all constructors defined by the given class.
1159 * Access checking is performed on behalf of the given {@code lookupClass}.
1160 * Inaccessible members are not added to the last.
1161 */
1162 public List<MemberName> getConstructors(Class<?> defc, Class<?> lookupClass) {
1163 return getMembers(defc, null, null, IS_CONSTRUCTOR, lookupClass);
1164 }
1165 /** Return a list of all fields defined by the given class.
1166 * Super types are searched (for inherited members) if {@code searchSupers} is true.
1167 * Access checking is performed on behalf of the given {@code lookupClass}.
1168 * Inaccessible members are not added to the last.
1169 */
1170 public List<MemberName> getFields(Class<?> defc, boolean searchSupers,
1171 Class<?> lookupClass) {
1172 return getFields(defc, searchSupers, null, null, lookupClass);
1173 }
1174 /** Return a list of all fields defined by the given class.
1175 * Super types are searched (for inherited members) if {@code searchSupers} is true.
1176 * Returned fields will match the name (if not null) and the type (if not null).
1177 * Access checking is performed on behalf of the given {@code lookupClass}.
1178 * Inaccessible members are not added to the last.
1179 */
1180 public List<MemberName> getFields(Class<?> defc, boolean searchSupers,
1181 String name, Class<?> type, Class<?> lookupClass) {
1182 int matchFlags = IS_FIELD | (searchSupers ? SEARCH_ALL_SUPERS : 0);
1183 return getMembers(defc, name, type, matchFlags, lookupClass);
1184 }
1185 /** Return a list of all nested types defined by the given class.
1186 * Super types are searched (for inherited members) if {@code searchSupers} is true.
1187 * Access checking is performed on behalf of the given {@code lookupClass}.
1188 * Inaccessible members are not added to the last.
1189 */
1190 public List<MemberName> getNestedTypes(Class<?> defc, boolean searchSupers,
1191 Class<?> lookupClass) {
1192 int matchFlags = IS_TYPE | (searchSupers ? SEARCH_ALL_SUPERS : 0);
1193 return getMembers(defc, null, null, matchFlags, lookupClass);
1194 }
1195 private static MemberName[] newMemberBuffer(int length) {
1196 MemberName[] buf = new MemberName[length];
1197 // fill the buffer with dummy structs for the JVM to fill in
1198 for (int i = 0; i < length; i++)
1199 buf[i] = new MemberName();
1200 return buf;
1201 }
1202 }
1203 }