1 /*
2 * Copyright (c) 2008, 2012, 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.Method;
34 import java.lang.reflect.Member;
35 import java.lang.reflect.Modifier;
36 import java.util.ArrayList;
37 import java.util.Arrays;
38 import java.util.Collections;
39 import java.util.Iterator;
40 import java.util.List;
41 import static java.lang.invoke.MethodHandleNatives.Constants.*;
42 import static java.lang.invoke.MethodHandleStatics.*;
43 import java.util.Objects;
44
45 /**
46 * A {@code MemberName} is a compact symbolic datum which fully characterizes
47 * a method or field reference.
48 * A member name refers to a field, method, constructor, or member type.
49 * Every member name has a simple name (a string) and a type (either a Class or MethodType).
50 * A member name may also have a non-null declaring class, or it may be simply
51 * a naked name/type pair.
52 * A member name may also have non-zero modifier flags.
53 * Finally, a member name may be either resolved or unresolved.
54 * If it is resolved, the existence of the named
55 * <p>
56 * Whether resolved or not, a member name provides no access rights or
57 * invocation capability to its possessor. It is merely a compact
58 * representation of all symbolic information necessary to link to
59 * and properly use the named member.
60 * <p>
61 * When resolved, a member name's internal implementation may include references to JVM metadata.
62 * This representation is stateless and only decriptive.
63 * It provides no private information and no capability to use the member.
64 * <p>
65 * By contrast, a {@linkplain java.lang.reflect.Method} contains fuller information
66 * about the internals of a method (except its bytecodes) and also
67 * allows invocation. A MemberName is much lighter than a Method,
68 * since it contains about 7 fields to the 16 of Method (plus its sub-arrays),
69 * and those seven fields omit much of the information in Method.
70 * @author jrose
71 */
72 /*non-public*/ final class MemberName implements Member, Cloneable {
73 private Class<?> clazz; // class in which the method is defined
74 private String name; // may be null if not yet materialized
75 private Object type; // may be null if not yet materialized
76 private int flags; // modifier bits; see reflect.Modifier
77 //@Injected JVM_Method* vmtarget;
78 //@Injected int vmindex;
79 private Object resolution; // if null, this guy is resolved
80
81 /** Return the declaring class of this member.
82 * In the case of a bare name and type, the declaring class will be null.
83 */
84 public Class<?> getDeclaringClass() {
85 return clazz;
86 }
87
88 /** Utility method producing the class loader of the declaring class. */
89 public ClassLoader getClassLoader() {
90 return clazz.getClassLoader();
91 }
92
93 /** Return the simple name of this member.
94 * For a type, it is the same as {@link Class#getSimpleName}.
95 * For a method or field, it is the simple name of the member.
96 * For a constructor, it is always {@code "<init>"}.
97 */
98 public String getName() {
99 if (name == null) {
100 expandFromVM();
101 if (name == null) return null;
102 }
103 return name;
104 }
105
106 public MethodType getMethodOrFieldType() {
107 if (isInvocable())
108 return getMethodType();
109 if (isGetter())
110 return MethodType.methodType(getFieldType());
111 if (isSetter())
112 return MethodType.methodType(void.class, getFieldType());
113 throw new InternalError("not a method or field: "+this);
114 }
115
116 /** Return the declared type of this member, which
117 * must be a method or constructor.
118 */
119 public MethodType getMethodType() {
120 if (type == null) {
121 expandFromVM();
122 if (type == null) return null;
123 }
124 if (!isInvocable())
125 throw newIllegalArgumentException("not invocable, no method type");
126 if (type instanceof MethodType) {
127 return (MethodType) type;
128 }
129 if (type instanceof String) {
130 String sig = (String) type;
131 MethodType res = MethodType.fromMethodDescriptorString(sig, getClassLoader());
132 this.type = res;
133 return res;
134 }
135 if (type instanceof Object[]) {
136 Object[] typeInfo = (Object[]) type;
137 Class<?>[] ptypes = (Class<?>[]) typeInfo[1];
138 Class<?> rtype = (Class<?>) typeInfo[0];
139 MethodType res = MethodType.methodType(rtype, ptypes);
140 this.type = res;
141 return res;
142 }
143 throw new InternalError("bad method type "+type);
144 }
145
146 /** Return the actual type under which this method or constructor must be invoked.
147 * For non-static methods or constructors, this is the type with a leading parameter,
148 * a reference to declaring class. For static methods, it is the same as the declared type.
149 */
150 public MethodType getInvocationType() {
151 MethodType itype = getMethodOrFieldType();
152 if (isConstructor() && getReferenceKind() == REF_newInvokeSpecial)
153 return itype.changeReturnType(clazz);
154 if (!isStatic())
155 return itype.insertParameterTypes(0, clazz);
156 return itype;
157 }
158
159 /** Utility method producing the parameter types of the method type. */
160 public Class<?>[] getParameterTypes() {
161 return getMethodType().parameterArray();
162 }
163
164 /** Utility method producing the return type of the method type. */
165 public Class<?> getReturnType() {
166 return getMethodType().returnType();
167 }
168
169 /** Return the declared type of this member, which
170 * must be a field or type.
171 * If it is a type member, that type itself is returned.
172 */
173 public Class<?> getFieldType() {
174 if (type == null) {
175 expandFromVM();
176 if (type == null) return null;
177 }
178 if (isInvocable())
179 throw newIllegalArgumentException("not a field or nested class, no simple type");
180 if (type instanceof Class<?>) {
181 return (Class<?>) type;
182 }
183 if (type instanceof String) {
184 String sig = (String) type;
185 MethodType mtype = MethodType.fromMethodDescriptorString("()"+sig, getClassLoader());
186 Class<?> res = mtype.returnType();
187 this.type = res;
188 return res;
189 }
190 throw new InternalError("bad field type "+type);
191 }
192
193 /** Utility method to produce either the method type or field type of this member. */
194 public Object getType() {
195 return (isInvocable() ? getMethodType() : getFieldType());
196 }
197
198 /** Utility method to produce the signature of this member,
199 * used within the class file format to describe its type.
200 */
201 public String getSignature() {
202 if (type == null) {
203 expandFromVM();
204 if (type == null) return null;
205 }
206 if (type instanceof String)
207 return (String) type;
208 if (isInvocable())
209 return BytecodeDescriptor.unparse(getMethodType());
210 else
211 return BytecodeDescriptor.unparse(getFieldType());
212 }
213
214 /** Return the modifier flags of this member.
215 * @see java.lang.reflect.Modifier
216 */
217 public int getModifiers() {
218 return (flags & RECOGNIZED_MODIFIERS);
219 }
220
221 /** Return the reference kind of this member, or zero if none.
222 */
223 public byte getReferenceKind() {
224 return (byte) ((flags >>> MN_REFERENCE_KIND_SHIFT) & MN_REFERENCE_KIND_MASK);
225 }
226 private boolean referenceKindIsConsistent() {
227 byte refKind = getReferenceKind();
228 if (refKind == REF_NONE) return isType();
229 if (isField()) {
230 assert(staticIsConsistent());
231 assert(MethodHandleNatives.refKindIsField(refKind));
232 } else if (isConstructor()) {
233 assert(refKind == REF_newInvokeSpecial || refKind == REF_invokeSpecial);
234 } else if (isMethod()) {
235 assert(staticIsConsistent());
236 assert(MethodHandleNatives.refKindIsMethod(refKind));
237 if (clazz.isInterface())
238 assert(refKind == REF_invokeInterface ||
239 refKind == REF_invokeStatic ||
240 refKind == REF_invokeSpecial ||
241 refKind == REF_invokeVirtual && isObjectPublicMethod());
242 } else {
243 assert(false);
244 }
245 return true;
246 }
247 private boolean isObjectPublicMethod() {
248 if (clazz == Object.class) return true;
249 MethodType mtype = getMethodType();
250 if (name.equals("toString") && mtype.returnType() == String.class && mtype.parameterCount() == 0)
251 return true;
252 if (name.equals("hashCode") && mtype.returnType() == int.class && mtype.parameterCount() == 0)
253 return true;
254 if (name.equals("equals") && mtype.returnType() == boolean.class && mtype.parameterCount() == 1 && mtype.parameterType(0) == Object.class)
255 return true;
256 return false;
257 }
258 /*non-public*/ boolean referenceKindIsConsistentWith(int originalRefKind) {
259 int refKind = getReferenceKind();
260 if (refKind == originalRefKind) return true;
261 switch (originalRefKind) {
262 case REF_invokeInterface:
263 // Looking up an interface method, can get (e.g.) Object.hashCode
264 assert(refKind == REF_invokeVirtual ||
265 refKind == REF_invokeSpecial) : this;
266 return true;
267 case REF_invokeVirtual:
268 case REF_newInvokeSpecial:
269 // Looked up a virtual, can get (e.g.) final String.hashCode.
270 assert(refKind == REF_invokeSpecial) : this;
271 return true;
272 }
273 assert(false) : this+" != "+MethodHandleNatives.refKindName((byte)originalRefKind);
274 return true;
275 }
276 private boolean staticIsConsistent() {
277 byte refKind = getReferenceKind();
278 return MethodHandleNatives.refKindIsStatic(refKind) == isStatic() || getModifiers() == 0;
279 }
280 private boolean vminfoIsConsistent() {
281 byte refKind = getReferenceKind();
282 assert(isResolved()); // else don't call
283 Object vminfo = MethodHandleNatives.getMemberVMInfo(this);
284 assert(vminfo instanceof Object[]);
285 long vmindex = (Long) ((Object[])vminfo)[0];
286 Object vmtarget = ((Object[])vminfo)[1];
287 if (MethodHandleNatives.refKindIsField(refKind)) {
288 assert(vmindex >= 0) : vmindex + ":" + this;
289 assert(vmtarget instanceof Class);
290 } else {
291 if (MethodHandleNatives.refKindDoesDispatch(refKind))
292 assert(vmindex >= 0) : vmindex + ":" + this;
293 else
294 assert(vmindex < 0) : vmindex;
295 assert(vmtarget instanceof MemberName) : vmtarget + " in " + this;
296 }
297 return true;
298 }
299
300 private MemberName changeReferenceKind(byte refKind, byte oldKind) {
301 assert(getReferenceKind() == oldKind);
302 assert(MethodHandleNatives.refKindIsValid(refKind));
303 flags += (((int)refKind - oldKind) << MN_REFERENCE_KIND_SHIFT);
304 // if (isConstructor() && refKind != REF_newInvokeSpecial)
305 // flags += (IS_METHOD - IS_CONSTRUCTOR);
306 // else if (refKind == REF_newInvokeSpecial && isMethod())
307 // flags += (IS_CONSTRUCTOR - IS_METHOD);
308 return this;
309 }
310
311 private boolean testFlags(int mask, int value) {
312 return (flags & mask) == value;
313 }
314 private boolean testAllFlags(int mask) {
315 return testFlags(mask, mask);
316 }
317 private boolean testAnyFlags(int mask) {
318 return !testFlags(mask, 0);
319 }
320
321 /** Utility method to query if this member is a method handle invocation (invoke or invokeExact). */
322 public boolean isMethodHandleInvoke() {
323 final int bits = Modifier.NATIVE | Modifier.FINAL;
324 final int negs = Modifier.STATIC;
325 if (testFlags(bits | negs, bits) &&
326 clazz == MethodHandle.class) {
327 return name.equals("invoke") || name.equals("invokeExact");
328 }
329 return false;
330 }
331
332 /** Utility method to query the modifier flags of this member. */
333 public boolean isStatic() {
334 return Modifier.isStatic(flags);
335 }
336 /** Utility method to query the modifier flags of this member. */
337 public boolean isPublic() {
338 return Modifier.isPublic(flags);
339 }
340 /** Utility method to query the modifier flags of this member. */
341 public boolean isPrivate() {
342 return Modifier.isPrivate(flags);
343 }
344 /** Utility method to query the modifier flags of this member. */
345 public boolean isProtected() {
346 return Modifier.isProtected(flags);
347 }
348 /** Utility method to query the modifier flags of this member. */
349 public boolean isFinal() {
350 return Modifier.isFinal(flags);
351 }
352 /** Utility method to query whether this member or its defining class is final. */
353 public boolean canBeStaticallyBound() {
354 return Modifier.isFinal(flags | clazz.getModifiers());
355 }
356 /** Utility method to query the modifier flags of this member. */
357 public boolean isVolatile() {
358 return Modifier.isVolatile(flags);
359 }
360 /** Utility method to query the modifier flags of this member. */
361 public boolean isAbstract() {
362 return Modifier.isAbstract(flags);
363 }
364 /** Utility method to query the modifier flags of this member. */
365 public boolean isNative() {
366 return Modifier.isNative(flags);
367 }
368 // let the rest (native, volatile, transient, etc.) be tested via Modifier.isFoo
369
370 // unofficial modifier flags, used by HotSpot:
371 static final int BRIDGE = 0x00000040;
372 static final int VARARGS = 0x00000080;
373 static final int SYNTHETIC = 0x00001000;
374 static final int ANNOTATION= 0x00002000;
375 static final int ENUM = 0x00004000;
376 /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
377 public boolean isBridge() {
378 return testAllFlags(IS_METHOD | BRIDGE);
379 }
380 /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
381 public boolean isVarargs() {
382 return testAllFlags(VARARGS) && isInvocable();
383 }
384 /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
385 public boolean isSynthetic() {
386 return testAllFlags(SYNTHETIC);
387 }
388
389 static final String CONSTRUCTOR_NAME = "<init>"; // the ever-popular
390
391 // modifiers exported by the JVM:
392 static final int RECOGNIZED_MODIFIERS = 0xFFFF;
393
394 // private flags, not part of RECOGNIZED_MODIFIERS:
395 static final int
396 IS_METHOD = MN_IS_METHOD, // method (not constructor)
397 IS_CONSTRUCTOR = MN_IS_CONSTRUCTOR, // constructor
398 IS_FIELD = MN_IS_FIELD, // field
399 IS_TYPE = MN_IS_TYPE, // nested type
400 CALLER_SENSITIVE = MN_CALLER_SENSITIVE; // @CallerSensitive annotation detected
401
402 static final int ALL_ACCESS = Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED;
403 static final int ALL_KINDS = IS_METHOD | IS_CONSTRUCTOR | IS_FIELD | IS_TYPE;
404 static final int IS_INVOCABLE = IS_METHOD | IS_CONSTRUCTOR;
405 static final int IS_FIELD_OR_METHOD = IS_METHOD | IS_FIELD;
406 static final int SEARCH_ALL_SUPERS = MN_SEARCH_SUPERCLASSES | MN_SEARCH_INTERFACES;
407
408 /** Utility method to query whether this member is a method or constructor. */
409 public boolean isInvocable() {
410 return testAnyFlags(IS_INVOCABLE);
411 }
412 /** Utility method to query whether this member is a method, constructor, or field. */
413 public boolean isFieldOrMethod() {
414 return testAnyFlags(IS_FIELD_OR_METHOD);
415 }
416 /** Query whether this member is a method. */
417 public boolean isMethod() {
418 return testAllFlags(IS_METHOD);
419 }
420 /** Query whether this member is a constructor. */
421 public boolean isConstructor() {
422 return testAllFlags(IS_CONSTRUCTOR);
423 }
424 /** Query whether this member is a field. */
425 public boolean isField() {
426 return testAllFlags(IS_FIELD);
427 }
428 /** Query whether this member is a type. */
429 public boolean isType() {
430 return testAllFlags(IS_TYPE);
431 }
432 /** Utility method to query whether this member is neither public, private, nor protected. */
433 public boolean isPackage() {
434 return !testAnyFlags(ALL_ACCESS);
435 }
436 /** Query whether this member has a CallerSensitive annotation. */
437 public boolean isCallerSensitive() {
438 return testAllFlags(CALLER_SENSITIVE);
439 }
440
441 /** Utility method to query whether this member is accessible from a given lookup class. */
442 public boolean isAccessibleFrom(Class<?> lookupClass) {
443 return VerifyAccess.isMemberAccessible(this.getDeclaringClass(), this.getDeclaringClass(), flags,
444 lookupClass, ALL_ACCESS|MethodHandles.Lookup.PACKAGE);
445 }
446
447 /** Initialize a query. It is not resolved. */
448 private void init(Class<?> defClass, String name, Object type, int flags) {
449 // defining class is allowed to be null (for a naked name/type pair)
450 //name.toString(); // null check
451 //type.equals(type); // null check
452 // fill in fields:
453 this.clazz = defClass;
454 this.name = name;
455 this.type = type;
456 this.flags = flags;
457 assert(testAnyFlags(ALL_KINDS));
458 assert(this.resolution == null); // nobody should have touched this yet
459 //assert(referenceKindIsConsistent()); // do this after resolution
460 }
461
462 private void expandFromVM() {
463 if (!isResolved()) return;
464 if (type instanceof Object[])
465 type = null; // don't saddle JVM w/ typeInfo
466 MethodHandleNatives.expand(this);
467 }
468
469 // Capturing information from the Core Reflection API:
470 private static int flagsMods(int flags, int mods, byte refKind) {
471 assert((flags & RECOGNIZED_MODIFIERS) == 0);
472 assert((mods & ~RECOGNIZED_MODIFIERS) == 0);
473 assert((refKind & ~MN_REFERENCE_KIND_MASK) == 0);
474 return flags | mods | (refKind << MN_REFERENCE_KIND_SHIFT);
475 }
476 /** Create a name for the given reflected method. The resulting name will be in a resolved state. */
477 public MemberName(Method m) {
478 this(m, false);
479 }
480 @SuppressWarnings("LeakingThisInConstructor")
481 public MemberName(Method m, boolean wantSpecial) {
482 m.getClass(); // NPE check
483 // fill in vmtarget, vmindex while we have m in hand:
484 MethodHandleNatives.init(this, m);
485 assert(isResolved() && this.clazz != null);
486 this.name = m.getName();
487 if (this.type == null)
488 this.type = new Object[] { m.getReturnType(), m.getParameterTypes() };
489 if (wantSpecial) {
490 assert(!isAbstract()) : this;
491 if (getReferenceKind() == REF_invokeVirtual)
492 changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual);
493 else if (getReferenceKind() == REF_invokeInterface)
494 // invokeSpecial on a default method
495 changeReferenceKind(REF_invokeSpecial, REF_invokeInterface);
496 }
497 }
498 public MemberName asSpecial() {
499 switch (getReferenceKind()) {
500 case REF_invokeSpecial: return this;
501 case REF_invokeVirtual: return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual);
502 case REF_invokeInterface: return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeInterface);
503 case REF_newInvokeSpecial: return clone().changeReferenceKind(REF_invokeSpecial, REF_newInvokeSpecial);
504 }
505 throw new IllegalArgumentException(this.toString());
506 }
507 public MemberName asConstructor() {
508 switch (getReferenceKind()) {
509 case REF_invokeSpecial: return clone().changeReferenceKind(REF_newInvokeSpecial, REF_invokeSpecial);
510 case REF_newInvokeSpecial: return this;
511 }
512 throw new IllegalArgumentException(this.toString());
513 }
514 /** Create a name for the given reflected constructor. The resulting name will be in a resolved state. */
515 @SuppressWarnings("LeakingThisInConstructor")
516 public MemberName(Constructor<?> ctor) {
517 ctor.getClass(); // NPE check
518 // fill in vmtarget, vmindex while we have ctor in hand:
519 MethodHandleNatives.init(this, ctor);
520 assert(isResolved() && this.clazz != null);
521 this.name = CONSTRUCTOR_NAME;
522 if (this.type == null)
523 this.type = new Object[] { void.class, ctor.getParameterTypes() };
524 }
525 /** Create a name for the given reflected field. The resulting name will be in a resolved state.
526 */
527 public MemberName(Field fld) {
528 this(fld, false);
529 }
530 @SuppressWarnings("LeakingThisInConstructor")
531 public MemberName(Field fld, boolean makeSetter) {
532 fld.getClass(); // NPE check
533 // fill in vmtarget, vmindex while we have fld in hand:
534 MethodHandleNatives.init(this, fld);
535 assert(isResolved() && this.clazz != null);
536 this.name = fld.getName();
537 this.type = fld.getType();
538 assert((REF_putStatic - REF_getStatic) == (REF_putField - REF_getField));
539 byte refKind = this.getReferenceKind();
540 assert(refKind == (isStatic() ? REF_getStatic : REF_getField));
541 if (makeSetter) {
542 changeReferenceKind((byte)(refKind + (REF_putStatic - REF_getStatic)), refKind);
543 }
544 }
545 public boolean isGetter() {
546 return MethodHandleNatives.refKindIsGetter(getReferenceKind());
547 }
548 public boolean isSetter() {
549 return MethodHandleNatives.refKindIsSetter(getReferenceKind());
550 }
551 public MemberName asSetter() {
552 byte refKind = getReferenceKind();
553 assert(MethodHandleNatives.refKindIsGetter(refKind));
554 assert((REF_putStatic - REF_getStatic) == (REF_putField - REF_getField));
555 byte setterRefKind = (byte)(refKind + (REF_putField - REF_getField));
556 return clone().changeReferenceKind(setterRefKind, refKind);
557 }
558 /** Create a name for the given class. The resulting name will be in a resolved state. */
559 public MemberName(Class<?> type) {
560 init(type.getDeclaringClass(), type.getSimpleName(), type,
561 flagsMods(IS_TYPE, type.getModifiers(), REF_NONE));
562 initResolved(true);
563 }
564
565 // bare-bones constructor; the JVM will fill it in
566 MemberName() { }
567
568 // locally useful cloner
569 @Override protected MemberName clone() {
570 try {
571 return (MemberName) super.clone();
572 } catch (CloneNotSupportedException ex) {
573 throw newInternalError(ex);
574 }
575 }
576
577 /** Get the definition of this member name.
578 * This may be in a super-class of the declaring class of this member.
579 */
580 public MemberName getDefinition() {
581 if (!isResolved()) throw new IllegalStateException("must be resolved: "+this);
582 if (isType()) return this;
583 MemberName res = this.clone();
584 res.clazz = null;
585 res.type = null;
586 res.name = null;
587 res.resolution = res;
588 res.expandFromVM();
589 assert(res.getName().equals(this.getName()));
590 return res;
591 }
592
593 @Override
594 public int hashCode() {
595 return Objects.hash(clazz, flags, name, getType());
596 }
597 @Override
598 public boolean equals(Object that) {
599 return (that instanceof MemberName && this.equals((MemberName)that));
600 }
601
602 /** Decide if two member names have exactly the same symbolic content.
603 * Does not take into account any actual class members, so even if
604 * two member names resolve to the same actual member, they may
605 * be distinct references.
606 */
607 public boolean equals(MemberName that) {
608 if (this == that) return true;
609 if (that == null) return false;
610 return this.clazz == that.clazz
611 && this.flags == that.flags
612 && Objects.equals(this.name, that.name)
613 && Objects.equals(this.getType(), that.getType());
614 }
615
616 // Construction from symbolic parts, for queries:
617 /** Create a field or type name from the given components: Declaring class, name, type, reference kind.
618 * The declaring class may be supplied as null if this is to be a bare name and type.
619 * The resulting name will in an unresolved state.
620 */
621 public MemberName(Class<?> defClass, String name, Class<?> type, byte refKind) {
622 init(defClass, name, type, flagsMods(IS_FIELD, 0, refKind));
623 initResolved(false);
624 }
625 /** Create a field or type name from the given components: Declaring class, name, type.
626 * The declaring class may be supplied as null if this is to be a bare name and type.
627 * The modifier flags default to zero.
628 * The resulting name will in an unresolved state.
629 */
630 public MemberName(Class<?> defClass, String name, Class<?> type, Void unused) {
631 this(defClass, name, type, REF_NONE);
632 initResolved(false);
633 }
634 /** Create a method or constructor name from the given components: Declaring class, name, type, modifiers.
635 * It will be a constructor if and only if the name is {@code "<init>"}.
636 * The declaring class may be supplied as null if this is to be a bare name and type.
637 * The last argument is optional, a boolean which requests REF_invokeSpecial.
638 * The resulting name will in an unresolved state.
639 */
640 public MemberName(Class<?> defClass, String name, MethodType type, byte refKind) {
641 @SuppressWarnings("LocalVariableHidesMemberVariable")
642 int flags = (name != null && name.equals(CONSTRUCTOR_NAME) ? IS_CONSTRUCTOR : IS_METHOD);
643 init(defClass, name, type, flagsMods(flags, 0, refKind));
644 initResolved(false);
645 }
646 // /** Create a method or constructor name from the given components: Declaring class, name, type, modifiers.
647 // * It will be a constructor if and only if the name is {@code "<init>"}.
648 // * The declaring class may be supplied as null if this is to be a bare name and type.
649 // * The modifier flags default to zero.
650 // * The resulting name will in an unresolved state.
651 // */
652 // public MemberName(Class<?> defClass, String name, MethodType type, Void unused) {
653 // this(defClass, name, type, REF_NONE);
654 // }
655
656 /** Query whether this member name is resolved to a non-static, non-final method.
657 */
658 public boolean hasReceiverTypeDispatch() {
659 return MethodHandleNatives.refKindDoesDispatch(getReferenceKind());
660 }
661
662 /** Query whether this member name is resolved.
663 * A resolved member name is one for which the JVM has found
664 * a method, constructor, field, or type binding corresponding exactly to the name.
665 * (Document?)
666 */
667 public boolean isResolved() {
668 return resolution == null;
669 }
670
671 private void initResolved(boolean isResolved) {
672 assert(this.resolution == null); // not initialized yet!
673 if (!isResolved)
674 this.resolution = this;
675 assert(isResolved() == isResolved);
676 }
677
678 void checkForTypeAlias() {
679 if (isInvocable()) {
680 MethodType type;
681 if (this.type instanceof MethodType)
682 type = (MethodType) this.type;
683 else
684 this.type = type = getMethodType();
685 if (type.erase() == type) return;
686 if (VerifyAccess.isTypeVisible(type, clazz)) return;
687 throw new LinkageError("bad method type alias: "+type+" not visible from "+clazz);
688 } else {
689 Class<?> type;
690 if (this.type instanceof Class<?>)
691 type = (Class<?>) this.type;
692 else
693 this.type = type = getFieldType();
694 if (VerifyAccess.isTypeVisible(type, clazz)) return;
695 throw new LinkageError("bad field type alias: "+type+" not visible from "+clazz);
696 }
697 }
698
699
700 /** Produce a string form of this member name.
701 * For types, it is simply the type's own string (as reported by {@code toString}).
702 * For fields, it is {@code "DeclaringClass.name/type"}.
703 * For methods and constructors, it is {@code "DeclaringClass.name(ptype...)rtype"}.
704 * If the declaring class is null, the prefix {@code "DeclaringClass."} is omitted.
705 * If the member is unresolved, a prefix {@code "*."} is prepended.
706 */
707 @SuppressWarnings("LocalVariableHidesMemberVariable")
708 @Override
709 public String toString() {
710 if (isType())
711 return type.toString(); // class java.lang.String
712 // else it is a field, method, or constructor
713 StringBuilder buf = new StringBuilder();
714 if (getDeclaringClass() != null) {
715 buf.append(getName(clazz));
716 buf.append('.');
717 }
718 String name = getName();
719 buf.append(name == null ? "*" : name);
720 Object type = getType();
721 if (!isInvocable()) {
722 buf.append('/');
723 buf.append(type == null ? "*" : getName(type));
724 } else {
725 buf.append(type == null ? "(*)*" : getName(type));
726 }
727 byte refKind = getReferenceKind();
728 if (refKind != REF_NONE) {
729 buf.append('/');
730 buf.append(MethodHandleNatives.refKindName(refKind));
731 }
732 //buf.append("#").append(System.identityHashCode(this));
733 return buf.toString();
734 }
735 private static String getName(Object obj) {
736 if (obj instanceof Class<?>)
737 return ((Class<?>)obj).getName();
738 return String.valueOf(obj);
739 }
740
741 public IllegalAccessException makeAccessException(String message, Object from) {
742 message = message + ": "+ toString();
743 if (from != null) message += ", from " + from;
744 return new IllegalAccessException(message);
745 }
746 private String message() {
747 if (isResolved())
748 return "no access";
749 else if (isConstructor())
750 return "no such constructor";
751 else if (isMethod())
752 return "no such method";
753 else
754 return "no such field";
755 }
756 public ReflectiveOperationException makeAccessException() {
757 String message = message() + ": "+ toString();
758 ReflectiveOperationException ex;
759 if (isResolved() || !(resolution instanceof NoSuchMethodError ||
760 resolution instanceof NoSuchFieldError))
761 ex = new IllegalAccessException(message);
762 else if (isConstructor())
763 ex = new NoSuchMethodException(message);
764 else if (isMethod())
765 ex = new NoSuchMethodException(message);
766 else
767 ex = new NoSuchFieldException(message);
768 if (resolution instanceof Throwable)
769 ex.initCause((Throwable) resolution);
770 return ex;
771 }
772
773 /** Actually making a query requires an access check. */
774 /*non-public*/ static Factory getFactory() {
775 return Factory.INSTANCE;
776 }
777 /** A factory type for resolving member names with the help of the VM.
778 * TBD: Define access-safe public constructors for this factory.
779 */
780 /*non-public*/ static class Factory {
781 private Factory() { } // singleton pattern
782 static Factory INSTANCE = new Factory();
783
784 private static int ALLOWED_FLAGS = ALL_KINDS;
785
786 /// Queries
787 List<MemberName> getMembers(Class<?> defc,
788 String matchName, Object matchType,
789 int matchFlags, Class<?> lookupClass) {
790 matchFlags &= ALLOWED_FLAGS;
791 String matchSig = null;
792 if (matchType != null) {
793 matchSig = BytecodeDescriptor.unparse(matchType);
794 if (matchSig.startsWith("("))
795 matchFlags &= ~(ALL_KINDS & ~IS_INVOCABLE);
796 else
797 matchFlags &= ~(ALL_KINDS & ~IS_FIELD);
798 }
799 final int BUF_MAX = 0x2000;
800 int len1 = matchName == null ? 10 : matchType == null ? 4 : 1;
801 MemberName[] buf = newMemberBuffer(len1);
802 int totalCount = 0;
803 ArrayList<MemberName[]> bufs = null;
804 int bufCount = 0;
805 for (;;) {
806 bufCount = MethodHandleNatives.getMembers(defc,
807 matchName, matchSig, matchFlags,
808 lookupClass,
809 totalCount, buf);
810 if (bufCount <= buf.length) {
811 if (bufCount < 0) bufCount = 0;
812 totalCount += bufCount;
813 break;
814 }
815 // JVM returned to us with an intentional overflow!
816 totalCount += buf.length;
817 int excess = bufCount - buf.length;
818 if (bufs == null) bufs = new ArrayList<>(1);
819 bufs.add(buf);
820 int len2 = buf.length;
821 len2 = Math.max(len2, excess);
822 len2 = Math.max(len2, totalCount / 4);
823 buf = newMemberBuffer(Math.min(BUF_MAX, len2));
824 }
825 ArrayList<MemberName> result = new ArrayList<>(totalCount);
826 if (bufs != null) {
827 for (MemberName[] buf0 : bufs) {
828 Collections.addAll(result, buf0);
829 }
830 }
831 result.addAll(Arrays.asList(buf).subList(0, bufCount));
832 // Signature matching is not the same as type matching, since
833 // one signature might correspond to several types.
834 // So if matchType is a Class or MethodType, refilter the results.
835 if (matchType != null && matchType != matchSig) {
836 for (Iterator<MemberName> it = result.iterator(); it.hasNext();) {
837 MemberName m = it.next();
838 if (!matchType.equals(m.getType()))
839 it.remove();
840 }
841 }
842 return result;
843 }
844 /** Produce a resolved version of the given member.
845 * Super types are searched (for inherited members) if {@code searchSupers} is true.
846 * Access checking is performed on behalf of the given {@code lookupClass}.
847 * If lookup fails or access is not permitted, null is returned.
848 * Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
849 */
850 private MemberName resolve(byte refKind, MemberName ref, Class<?> lookupClass) {
851 MemberName m = ref.clone(); // JVM will side-effect the ref
852 assert(refKind == m.getReferenceKind());
853 try {
854 m = MethodHandleNatives.resolve(m, lookupClass);
855 m.checkForTypeAlias();
856 m.resolution = null;
857 } catch (LinkageError ex) {
858 // JVM reports that the "bytecode behavior" would get an error
859 assert(!m.isResolved());
860 m.resolution = ex;
861 return m;
862 }
863 assert(m.referenceKindIsConsistent());
864 m.initResolved(true);
865 assert(m.vminfoIsConsistent());
866 return m;
867 }
868 /** Produce a resolved version of the given member.
869 * Super types are searched (for inherited members) if {@code searchSupers} is true.
870 * Access checking is performed on behalf of the given {@code lookupClass}.
871 * If lookup fails or access is not permitted, a {@linkplain ReflectiveOperationException} is thrown.
872 * Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
873 */
874 public
875 <NoSuchMemberException extends ReflectiveOperationException>
876 MemberName resolveOrFail(byte refKind, MemberName m, Class<?> lookupClass,
877 Class<NoSuchMemberException> nsmClass)
878 throws IllegalAccessException, NoSuchMemberException {
879 MemberName result = resolve(refKind, m, lookupClass);
880 if (result.isResolved())
881 return result;
882 ReflectiveOperationException ex = result.makeAccessException();
883 if (ex instanceof IllegalAccessException) throw (IllegalAccessException) ex;
884 throw nsmClass.cast(ex);
885 }
886 /** Produce a resolved version of the given member.
887 * Super types are searched (for inherited members) if {@code searchSupers} is true.
888 * Access checking is performed on behalf of the given {@code lookupClass}.
889 * If lookup fails or access is not permitted, return null.
890 * Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
891 */
892 public
893 MemberName resolveOrNull(byte refKind, MemberName m, Class<?> lookupClass) {
894 MemberName result = resolve(refKind, m, lookupClass);
895 if (result.isResolved())
896 return result;
897 return null;
898 }
899 /** Return a list of all methods defined by the given class.
900 * Super types are searched (for inherited members) if {@code searchSupers} is true.
901 * Access checking is performed on behalf of the given {@code lookupClass}.
902 * Inaccessible members are not added to the last.
903 */
904 public List<MemberName> getMethods(Class<?> defc, boolean searchSupers,
905 Class<?> lookupClass) {
906 return getMethods(defc, searchSupers, null, null, lookupClass);
907 }
908 /** Return a list of matching methods defined by the given class.
909 * Super types are searched (for inherited members) if {@code searchSupers} is true.
910 * Returned methods will match the name (if not null) and the type (if not null).
911 * Access checking is performed on behalf of the given {@code lookupClass}.
912 * Inaccessible members are not added to the last.
913 */
914 public List<MemberName> getMethods(Class<?> defc, boolean searchSupers,
915 String name, MethodType type, Class<?> lookupClass) {
916 int matchFlags = IS_METHOD | (searchSupers ? SEARCH_ALL_SUPERS : 0);
917 return getMembers(defc, name, type, matchFlags, lookupClass);
918 }
919 /** Return a list of all constructors defined by the given class.
920 * Access checking is performed on behalf of the given {@code lookupClass}.
921 * Inaccessible members are not added to the last.
922 */
923 public List<MemberName> getConstructors(Class<?> defc, Class<?> lookupClass) {
924 return getMembers(defc, null, null, IS_CONSTRUCTOR, lookupClass);
925 }
926 /** Return a list of all fields defined by the given class.
927 * Super types are searched (for inherited members) if {@code searchSupers} is true.
928 * Access checking is performed on behalf of the given {@code lookupClass}.
929 * Inaccessible members are not added to the last.
930 */
931 public List<MemberName> getFields(Class<?> defc, boolean searchSupers,
932 Class<?> lookupClass) {
933 return getFields(defc, searchSupers, null, null, lookupClass);
934 }
935 /** Return a list of all fields defined by the given class.
936 * Super types are searched (for inherited members) if {@code searchSupers} is true.
937 * Returned fields will match the name (if not null) and the type (if not null).
938 * Access checking is performed on behalf of the given {@code lookupClass}.
939 * Inaccessible members are not added to the last.
940 */
941 public List<MemberName> getFields(Class<?> defc, boolean searchSupers,
942 String name, Class<?> type, Class<?> lookupClass) {
943 int matchFlags = IS_FIELD | (searchSupers ? SEARCH_ALL_SUPERS : 0);
944 return getMembers(defc, name, type, matchFlags, lookupClass);
945 }
946 /** Return a list of all nested types defined by the given class.
947 * Super types are searched (for inherited members) if {@code searchSupers} is true.
948 * Access checking is performed on behalf of the given {@code lookupClass}.
949 * Inaccessible members are not added to the last.
950 */
951 public List<MemberName> getNestedTypes(Class<?> defc, boolean searchSupers,
952 Class<?> lookupClass) {
953 int matchFlags = IS_TYPE | (searchSupers ? SEARCH_ALL_SUPERS : 0);
954 return getMembers(defc, null, null, matchFlags, lookupClass);
955 }
956 private static MemberName[] newMemberBuffer(int length) {
957 MemberName[] buf = new MemberName[length];
958 // fill the buffer with dummy structs for the JVM to fill in
959 for (int i = 0; i < length; i++)
960 buf[i] = new MemberName();
961 return buf;
962 }
963 }
964
965 // static {
966 // System.out.println("Hello world! My methods are:");
967 // System.out.println(Factory.INSTANCE.getMethods(MemberName.class, true, null));
968 // }
969 }