1/* 2 * Copyright (c) 2008, 2016, 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 26package java.lang.invoke; 27 28import sun.invoke.util.BytecodeDescriptor; 29import sun.invoke.util.VerifyAccess; 30 31import java.lang.reflect.Constructor; 32import java.lang.reflect.Field; 33import java.lang.reflect.Member; 34import java.lang.reflect.Method; 35import java.lang.reflect.Modifier; 36import java.util.ArrayList; 37import java.util.Collections; 38import java.util.Iterator; 39import java.util.List; 40import java.util.Objects; 41 42import static java.lang.invoke.MethodHandleNatives.Constants.*; 43import static java.lang.invoke.MethodHandleStatics.newIllegalArgumentException; 44import 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 MemberName implements Member, Cloneable { 74 private Class<?> clazz; // class in which the method is defined 75 private String name; // may be null if not yet materialized 76 private Object type; // may be null if not yet materialized 77 private int flags; // modifier bits; see reflect.Modifier 78 //@Injected JVM_Method* vmtarget; 79 //@Injected int vmindex; 80 Object resolution; // if null, this guy is resolved 81 82 /** Return the declaring class of this member. 83 * In the case of a bare name and type, the declaring class will be null. 84 */ 85 public Class<?> getDeclaringClass() { 86 return clazz; 87 } 88 89 /** Utility method producing the class loader of the declaring class. */ 90 public ClassLoader getClassLoader() { 91 return clazz.getClassLoader(); 92 } 93 94 /** Return the simple name of this member. 95 * For a type, it is the same as {@link Class#getSimpleName}. 96 * For a method or field, it is the simple name of the member. 97 * For a constructor, it is always {@code "<init>"}. 98 */ 99 public String getName() { 100 if (name == null) { 101 expandFromVM(); 102 if (name == null) { 103 return null; 104 } 105 } 106 return name; 107 } 108 109 public MethodType getMethodOrFieldType() { 110 if (isInvocable()) 111 return getMethodType(); 112 if (isGetter()) 113 return MethodType.methodType(getFieldType()); 114 if (isSetter()) 115 return MethodType.methodType(void.class, getFieldType()); 116 throw new InternalError("not a method or field: "+this); 117 } 118 119 /** Return the declared type of this member, which 120 * must be a method or constructor. 121 */ 122 public MethodType getMethodType() { 123 if (type == null) { 124 expandFromVM(); 125 if (type == null) { 126 return null; 127 } 128 } 129 if (!isInvocable()) { 130 throw newIllegalArgumentException("not invocable, no method type"); 131 } 132 133 { 134 // Get a snapshot of type which doesn't get changed by racing threads. 135 final Object type = this.type; 136 if (type instanceof MethodType) { 137 return (MethodType) type; 138 } 139 } 140 141 // type is not a MethodType yet. Convert it thread-safely. 142 synchronized (this) { 143 if (type instanceof String) { 144 String sig = (String) type; 145 MethodType res = MethodType.fromDescriptor(sig, getClassLoader()); 146 type = res; 147 } else if (type instanceof Object[]) { 148 Object[] typeInfo = (Object[]) type; 149 Class<?>[] ptypes = (Class<?>[]) typeInfo[1]; 150 Class<?> rtype = (Class<?>) typeInfo[0]; 151 MethodType res = MethodType.methodType(rtype, ptypes); 152 type = res; 153 } 154 // Make sure type is a MethodType for racing threads. 155 assert type instanceof MethodType : "bad method type " + type; 156 } 157 return (MethodType) type; 158 } 159 160 /** Return the actual type under which this method or constructor must be invoked. 161 * For non-static methods or constructors, this is the type with a leading parameter, 162 * a reference to declaring class. For static methods, it is the same as the declared type. 163 */ 164 public MethodType getInvocationType() { 165 MethodType itype = getMethodOrFieldType(); 166 if (isConstructor() && getReferenceKind() == REF_newInvokeSpecial) 167 return itype.changeReturnType(clazz); 168 if (!isStatic()) 169 return itype.insertParameterTypes(0, clazz); 170 return itype; 171 } 172 173 /** Utility method producing the parameter types of the method type. */ 174 public Class<?>[] getParameterTypes() { 175 return getMethodType().parameterArray(); 176 } 177 178 /** Utility method producing the return type of the method type. */ 179 public Class<?> getReturnType() { 180 return getMethodType().returnType(); 181 } 182 183 /** Return the declared type of this member, which 184 * must be a field or type. 185 * If it is a type member, that type itself is returned. 186 */ 187 public Class<?> getFieldType() { 188 if (type == null) { 189 expandFromVM(); 190 if (type == null) { 191 return null; 192 } 193 } 194 if (isInvocable()) { 195 throw newIllegalArgumentException("not a field or nested class, no simple type"); 196 } 197 198 { 199 // Get a snapshot of type which doesn't get changed by racing threads. 200 final Object type = this.type; 201 if (type instanceof Class<?>) { 202 return (Class<?>) type; 203 } 204 } 205 206 // type is not a Class yet. Convert it thread-safely. 207 synchronized (this) { 208 if (type instanceof String) { 209 String sig = (String) type; 210 MethodType mtype = MethodType.fromDescriptor("()"+sig, getClassLoader()); 211 Class<?> res = mtype.returnType(); 212 type = res; 213 } 214 // Make sure type is a Class for racing threads. 215 assert type instanceof Class<?> : "bad field type " + type; 216 } 217 return (Class<?>) type; 218 } 219 220 /** Utility method to produce either the method type or field type of this member. */ 221 public Object getType() { 222 return (isInvocable() ? getMethodType() : getFieldType()); 223 } 224 225 /** Utility method to produce the signature of this member, 226 * used within the class file format to describe its type. 227 */ 228 public String getSignature() { 229 if (type == null) { 230 expandFromVM(); 231 if (type == null) { 232 return null; 233 } 234 } 235 if (isInvocable()) 236 return BytecodeDescriptor.unparse(getMethodType()); 237 else 238 return BytecodeDescriptor.unparse(getFieldType()); 239 } 240 241 /** Return the modifier flags of this member. 242 * @see java.lang.reflect.Modifier 243 */ 244 public int getModifiers() { 245 return (flags & RECOGNIZED_MODIFIERS); 246 } 247 248 /** Return the reference kind of this member, or zero if none. 249 */ 250 public byte getReferenceKind() { 251 return (byte) ((flags >>> MN_REFERENCE_KIND_SHIFT) & MN_REFERENCE_KIND_MASK); 252 } 253 private boolean referenceKindIsConsistent() { 254 byte refKind = getReferenceKind(); 255 if (refKind == REF_NONE) return isType(); 256 if (isField()) { 257 assert(staticIsConsistent()); 258 assert(MethodHandleNatives.refKindIsField(refKind)); 259 } else if (isConstructor()) { 260 assert(refKind == REF_newInvokeSpecial || refKind == REF_invokeSpecial); 261 } else if (isMethod()) { 262 assert(staticIsConsistent()); 263 assert(MethodHandleNatives.refKindIsMethod(refKind)); 264 if (clazz.isInterface()) 265 assert(refKind == REF_invokeInterface || 266 refKind == REF_invokeStatic || 267 refKind == REF_invokeSpecial || 268 refKind == REF_invokeVirtual && isObjectPublicMethod()); 269 } else { 270 assert(false); 271 } 272 return true; 273 } 274 private boolean isObjectPublicMethod() { 275 if (clazz == Object.class) return true; 276 MethodType mtype = getMethodType(); 277 if (name.equals("toString") && mtype.returnType() == String.class && mtype.parameterCount() == 0) 278 return true; 279 if (name.equals("hashCode") && mtype.returnType() == int.class && mtype.parameterCount() == 0) 280 return true; 281 if (name.equals("equals") && mtype.returnType() == boolean.class && mtype.parameterCount() == 1 && mtype.parameterType(0) == Object.class) 282 return true; 283 return false; 284 } 285 /*non-public*/ boolean referenceKindIsConsistentWith(int originalRefKind) { 286 int refKind = getReferenceKind(); 287 if (refKind == originalRefKind) return true; 288 switch (originalRefKind) { 289 case REF_invokeInterface: 290 // Looking up an interface method, can get (e.g.) Object.hashCode 291 assert(refKind == REF_invokeVirtual || 292 refKind == REF_invokeSpecial) : this; 293 return true; 294 case REF_invokeVirtual: 295 case REF_newInvokeSpecial: 296 // Looked up a virtual, can get (e.g.) final String.hashCode. 297 assert(refKind == REF_invokeSpecial) : this; 298 return true; 299 } 300 assert(false) : this+" != "+MethodHandleNatives.refKindName((byte)originalRefKind); 301 return true; 302 } 303 private boolean staticIsConsistent() { 304 byte refKind = getReferenceKind(); 305 return MethodHandleNatives.refKindIsStatic(refKind) == isStatic() || getModifiers() == 0; 306 } 307 private boolean vminfoIsConsistent() { 308 byte refKind = getReferenceKind(); 309 assert(isResolved()); // else don't call 310 Object vminfo = MethodHandleNatives.getMemberVMInfo(this); 311 assert(vminfo instanceof Object[]); 312 long vmindex = (Long) ((Object[])vminfo)[0]; 313 Object vmtarget = ((Object[])vminfo)[1]; 314 if (MethodHandleNatives.refKindIsField(refKind)) { 315 assert(vmindex >= 0) : vmindex + ":" + this; 316 assert(vmtarget instanceof Class); 317 } else { 318 if (MethodHandleNatives.refKindDoesDispatch(refKind)) 319 assert(vmindex >= 0) : vmindex + ":" + this; 320 else 321 assert(vmindex < 0) : vmindex; 322 assert(vmtarget instanceof MemberName) : vmtarget + " in " + this; 323 } 324 return true; 325 } 326 327 private MemberName changeReferenceKind(byte refKind, byte oldKind) { 328 assert(getReferenceKind() == oldKind); 329 assert(MethodHandleNatives.refKindIsValid(refKind)); 330 flags += (((int)refKind - oldKind) << MN_REFERENCE_KIND_SHIFT); 331 return this; 332 } 333 334 private boolean testFlags(int mask, int value) { 335 return (flags & mask) == value; 336 } 337 private boolean testAllFlags(int mask) { 338 return testFlags(mask, mask); 339 } 340 private boolean testAnyFlags(int mask) { 341 return !testFlags(mask, 0); 342 } 343 344 /** Utility method to query if this member is a method handle invocation (invoke or invokeExact). 345 */ 346 public boolean isMethodHandleInvoke() { 347 final int bits = MH_INVOKE_MODS &~ Modifier.PUBLIC; 348 final int negs = Modifier.STATIC; 349 if (testFlags(bits | negs, bits) && 350 clazz == MethodHandle.class) { 351 return isMethodHandleInvokeName(name); 352 } 353 return false; 354 } 355 public static boolean isMethodHandleInvokeName(String name) { 356 switch (name) { 357 case "invoke": 358 case "invokeExact": 359 return true; 360 default: 361 return false; 362 } 363 } 364 public boolean isVarHandleMethodInvoke() { 365 final int bits = MH_INVOKE_MODS &~ Modifier.PUBLIC; 366 final int negs = Modifier.STATIC; 367 if (testFlags(bits | negs, bits) && 368 clazz == VarHandle.class) { 369 return isVarHandleMethodInvokeName(name); 370 } 371 return false; 372 } 373 public static boolean isVarHandleMethodInvokeName(String name) { 374 try { 375 VarHandle.AccessMode.valueFromMethodName(name); 376 return true; 377 } catch (IllegalArgumentException e) { 378 return false; 379 } 380 } 381 private static final int MH_INVOKE_MODS = Modifier.NATIVE | Modifier.FINAL | Modifier.PUBLIC; 382 383 /** Utility method to query the modifier flags of this member. */ 384 public boolean isStatic() { 385 return Modifier.isStatic(flags); 386 } 387 /** Utility method to query the modifier flags of this member. */ 388 public boolean isPublic() { 389 return Modifier.isPublic(flags); 390 } 391 /** Utility method to query the modifier flags of this member. */ 392 public boolean isPrivate() { 393 return Modifier.isPrivate(flags); 394 } 395 /** Utility method to query the modifier flags of this member. */ 396 public boolean isProtected() { 397 return Modifier.isProtected(flags); 398 } 399 /** Utility method to query the modifier flags of this member. */ 400 public boolean isFinal() { 401 return Modifier.isFinal(flags); 402 } 403 /** Utility method to query whether this member or its defining class is final. */ 404 public boolean canBeStaticallyBound() { 405 return Modifier.isFinal(flags | clazz.getModifiers()); 406 } 407 /** Utility method to query the modifier flags of this member. */ 408 public boolean isVolatile() { 409 return Modifier.isVolatile(flags); 410 } 411 /** Utility method to query the modifier flags of this member. */ 412 public boolean isAbstract() { 413 return Modifier.isAbstract(flags); 414 } 415 /** Utility method to query the modifier flags of this member. */ 416 public boolean isNative() { 417 return Modifier.isNative(flags); 418 } 419 // let the rest (native, volatile, transient, etc.) be tested via Modifier.isFoo 420 421 // unofficial modifier flags, used by HotSpot: 422 static final int BRIDGE = 0x00000040; 423 static final int VARARGS = 0x00000080; 424 static final int SYNTHETIC = 0x00001000; 425 static final int ANNOTATION= 0x00002000; 426 static final int ENUM = 0x00004000; 427 /** 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 testAllFlags(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 testAllFlags(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 testAllFlags(SYNTHETIC); 438 } 439 440 static final String CONSTRUCTOR_NAME = "<init>"; // the ever-popular 441 442 // modifiers exported by the JVM: 443 static final int RECOGNIZED_MODIFIERS = 0xFFFF; 444 445 // private flags, not part of RECOGNIZED_MODIFIERS: 446 static final int 447 IS_METHOD = MN_IS_METHOD, // method (not constructor) 448 IS_CONSTRUCTOR = MN_IS_CONSTRUCTOR, // constructor 449 IS_FIELD = MN_IS_FIELD, // field 450 IS_TYPE = MN_IS_TYPE, // nested type 451 CALLER_SENSITIVE = MN_CALLER_SENSITIVE; // @CallerSensitive annotation detected 452 453 static final int ALL_ACCESS = Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED; 454 static final int ALL_KINDS = IS_METHOD | IS_CONSTRUCTOR | IS_FIELD | IS_TYPE; 455 static final int IS_INVOCABLE = IS_METHOD | IS_CONSTRUCTOR; 456 static final int IS_FIELD_OR_METHOD = IS_METHOD | IS_FIELD; 457 static final int SEARCH_ALL_SUPERS = MN_SEARCH_SUPERCLASSES | MN_SEARCH_INTERFACES; 458 459 /** Utility method to query whether this member is a method or constructor. */ 460 public boolean isInvocable() { 461 return testAnyFlags(IS_INVOCABLE); 462 } 463 /** Utility method to query whether this member is a method, constructor, or field. */ 464 public boolean isFieldOrMethod() { 465 return testAnyFlags(IS_FIELD_OR_METHOD); 466 } 467 /** Query whether this member is a method. */ 468 public boolean isMethod() { 469 return testAllFlags(IS_METHOD); 470 } 471 /** Query whether this member is a constructor. */ 472 public boolean isConstructor() { 473 return testAllFlags(IS_CONSTRUCTOR); 474 } 475 /** Query whether this member is a field. */ 476 public boolean isField() { 477 return testAllFlags(IS_FIELD); 478 } 479 /** Query whether this member is a type. */ 480 public boolean isType() { 481 return testAllFlags(IS_TYPE); 482 } 483 /** Utility method to query whether this member is neither public, private, nor protected. */ 484 public boolean isPackage() { 485 return !testAnyFlags(ALL_ACCESS); 486 } 487 /** Query whether this member has a CallerSensitive annotation. */ 488 public boolean isCallerSensitive() { 489 return testAllFlags(CALLER_SENSITIVE); 490 } 491 492 /** Utility method to query whether this member is accessible from a given lookup class. */ 493 public boolean isAccessibleFrom(Class<?> lookupClass) { 494 int mode = (ALL_ACCESS|MethodHandles.Lookup.PACKAGE|MethodHandles.Lookup.MODULE); 495 return VerifyAccess.isMemberAccessible(this.getDeclaringClass(), this.getDeclaringClass(), flags, 496 lookupClass, mode); 497 } 498 499 /** 500 * Check if MemberName is a call to a method named {@code name} in class {@code declaredClass}. 501 */ 502 public boolean refersTo(Class<?> declc, String n) { 503 return clazz == declc && getName().equals(n); 504 } 505 506 /** Initialize a query. It is not resolved. */ 507 private void init(Class<?> defClass, String name, Object type, int flags) { 508 // defining class is allowed to be null (for a naked name/type pair) 509 //name.toString(); // null check 510 //type.equals(type); // null check 511 // fill in fields: 512 this.clazz = defClass; 513 this.name = name; 514 this.type = type; 515 this.flags = flags; 516 assert(testAnyFlags(ALL_KINDS)); 517 assert(this.resolution == null); // nobody should have touched this yet 518 //assert(referenceKindIsConsistent()); // do this after resolution 519 } 520 521 /** 522 * Calls down to the VM to fill in the fields. This method is 523 * synchronized to avoid racing calls. 524 */ 525 private void expandFromVM() { 526 if (type != null) { 527 return; 528 } 529 if (!isResolved()) { 530 return; 531 } 532 MethodHandleNatives.expand(this); 533 } 534 535 // Capturing information from the Core Reflection API: 536 private static int flagsMods(int flags, int mods, byte refKind) { 537 assert((flags & RECOGNIZED_MODIFIERS) == 0); 538 assert((mods & ~RECOGNIZED_MODIFIERS) == 0); 539 assert((refKind & ~MN_REFERENCE_KIND_MASK) == 0); 540 return flags | mods | (refKind << MN_REFERENCE_KIND_SHIFT); 541 } 542 /** Create a name for the given reflected method. The resulting name will be in a resolved state. */ 543 public MemberName(Method m) { 544 this(m, false); 545 } 546 @SuppressWarnings("LeakingThisInConstructor") 547 public MemberName(Method m, boolean wantSpecial) { 548 Objects.requireNonNull(m); 549 // fill in vmtarget, vmindex while we have m in hand: 550 MethodHandleNatives.init(this, m); 551 if (clazz == null) { // MHN.init failed 552 if (m.getDeclaringClass() == MethodHandle.class && 553 isMethodHandleInvokeName(m.getName())) { 554 // The JVM did not reify this signature-polymorphic instance. 555 // Need a special case here. 556 // See comments on MethodHandleNatives.linkMethod. 557 MethodType type = MethodType.methodType(m.getReturnType(), m.getParameterTypes()); 558 int flags = flagsMods(IS_METHOD, m.getModifiers(), REF_invokeVirtual); 559 init(MethodHandle.class, m.getName(), type, flags); 560 if (isMethodHandleInvoke()) 561 return; 562 } 563 if (m.getDeclaringClass() == VarHandle.class && 564 isVarHandleMethodInvokeName(m.getName())) { 565 // The JVM did not reify this signature-polymorphic instance. 566 // Need a special case here. 567 // See comments on MethodHandleNatives.linkMethod. 568 MethodType type = MethodType.methodType(m.getReturnType(), m.getParameterTypes()); 569 int flags = flagsMods(IS_METHOD, m.getModifiers(), REF_invokeVirtual); 570 init(VarHandle.class, m.getName(), type, flags); 571 if (isVarHandleMethodInvoke()) 572 return; 573 } 574 throw new LinkageError(m.toString()); 575 } 576 assert(isResolved() && this.clazz != null); 577 this.name = m.getName(); 578 if (this.type == null) 579 this.type = new Object[] { m.getReturnType(), m.getParameterTypes() }; 580 if (wantSpecial) { 581 if (isAbstract()) 582 throw new AbstractMethodError(this.toString()); 583 if (getReferenceKind() == REF_invokeVirtual) 584 changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual); 585 else if (getReferenceKind() == REF_invokeInterface) 586 // invokeSpecial on a default method 587 changeReferenceKind(REF_invokeSpecial, REF_invokeInterface); 588 } 589 } 590 public MemberName asSpecial() { 591 switch (getReferenceKind()) { 592 case REF_invokeSpecial: return this; 593 case REF_invokeVirtual: return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual); 594 case REF_invokeInterface: return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeInterface); 595 case REF_newInvokeSpecial: return clone().changeReferenceKind(REF_invokeSpecial, REF_newInvokeSpecial); 596 } 597 throw new IllegalArgumentException(this.toString()); 598 } 599 /** If this MN is not REF_newInvokeSpecial, return a clone with that ref. kind. 600 * In that case it must already be REF_invokeSpecial. 601 */ 602 public MemberName asConstructor() { 603 switch (getReferenceKind()) { 604 case REF_invokeSpecial: return clone().changeReferenceKind(REF_newInvokeSpecial, REF_invokeSpecial); 605 case REF_newInvokeSpecial: return this; 606 } 607 throw new IllegalArgumentException(this.toString()); 608 } 609 /** If this MN is a REF_invokeSpecial, return a clone with the "normal" kind 610 * REF_invokeVirtual; also switch either to REF_invokeInterface if clazz.isInterface. 611 * The end result is to get a fully virtualized version of the MN. 612 * (Note that resolving in the JVM will sometimes devirtualize, changing 613 * REF_invokeVirtual of a final to REF_invokeSpecial, and REF_invokeInterface 614 * in some corner cases to either of the previous two; this transform 615 * undoes that change under the assumption that it occurred.) 616 */ 617 public MemberName asNormalOriginal() { 618 byte normalVirtual = clazz.isInterface() ? REF_invokeInterface : REF_invokeVirtual; 619 byte refKind = getReferenceKind(); 620 byte newRefKind = refKind; 621 MemberName result = this; 622 switch (refKind) { 623 case REF_invokeInterface: 624 case REF_invokeVirtual: 625 case REF_invokeSpecial: 626 newRefKind = normalVirtual; 627 break; 628 } 629 if (newRefKind == refKind) 630 return this; 631 result = clone().changeReferenceKind(newRefKind, refKind); 632 assert(this.referenceKindIsConsistentWith(result.getReferenceKind())); 633 return result; 634 } 635 /** Create a name for the given reflected constructor. The resulting name will be in a resolved state. */ 636 @SuppressWarnings("LeakingThisInConstructor") 637 public MemberName(Constructor<?> ctor) { 638 Objects.requireNonNull(ctor); 639 // fill in vmtarget, vmindex while we have ctor in hand: 640 MethodHandleNatives.init(this, ctor); 641 assert(isResolved() && this.clazz != null); 642 this.name = CONSTRUCTOR_NAME; 643 if (this.type == null) 644 this.type = new Object[] { void.class, ctor.getParameterTypes() }; 645 } 646 /** Create a name for the given reflected field. The resulting name will be in a resolved state. 647 */ 648 public MemberName(Field fld) { 649 this(fld, false); 650 } 651 @SuppressWarnings("LeakingThisInConstructor") 652 public MemberName(Field fld, boolean makeSetter) { 653 Objects.requireNonNull(fld); 654 // fill in vmtarget, vmindex while we have fld in hand: 655 MethodHandleNatives.init(this, fld); 656 assert(isResolved() && this.clazz != null); 657 this.name = fld.getName(); 658 this.type = fld.getType(); 659 assert((REF_putStatic - REF_getStatic) == (REF_putField - REF_getField)); 660 byte refKind = this.getReferenceKind(); 661 assert(refKind == (isStatic() ? REF_getStatic : REF_getField)); 662 if (makeSetter) { 663 changeReferenceKind((byte)(refKind + (REF_putStatic - REF_getStatic)), refKind); 664 } 665 } 666 public boolean isGetter() { 667 return MethodHandleNatives.refKindIsGetter(getReferenceKind()); 668 } 669 public boolean isSetter() { 670 return MethodHandleNatives.refKindIsSetter(getReferenceKind()); 671 } 672 public MemberName asSetter() { 673 byte refKind = getReferenceKind(); 674 assert(MethodHandleNatives.refKindIsGetter(refKind)); 675 assert((REF_putStatic - REF_getStatic) == (REF_putField - REF_getField)); 676 byte setterRefKind = (byte)(refKind + (REF_putField - REF_getField)); 677 return clone().changeReferenceKind(setterRefKind, refKind); 678 } 679 /** Create a name for the given class. The resulting name will be in a resolved state. */ 680 public MemberName(Class<?> type) { 681 init(type.getDeclaringClass(), type.getSimpleName(), type, 682 flagsMods(IS_TYPE, type.getModifiers(), REF_NONE)); 683 initResolved(true); 684 } 685 686 /** 687 * Create a name for a signature-polymorphic invoker. 688 * This is a placeholder for a signature-polymorphic instance 689 * (of MH.invokeExact, etc.) that the JVM does not reify. 690 * See comments on {@link MethodHandleNatives#linkMethod}. 691 */ 692 static MemberName makeMethodHandleInvoke(String name, MethodType type) { 693 return makeMethodHandleInvoke(name, type, MH_INVOKE_MODS | SYNTHETIC); 694 } 695 static MemberName makeMethodHandleInvoke(String name, MethodType type, int mods) { 696 MemberName mem = new MemberName(MethodHandle.class, name, type, REF_invokeVirtual); 697 mem.flags |= mods; // it's not resolved, but add these modifiers anyway 698 assert(mem.isMethodHandleInvoke()) : mem; 699 return mem; 700 } 701 702 static MemberName makeVarHandleMethodInvoke(String name, MethodType type) { 703 return makeVarHandleMethodInvoke(name, type, MH_INVOKE_MODS | SYNTHETIC); 704 } 705 static MemberName makeVarHandleMethodInvoke(String name, MethodType type, int mods) { 706 MemberName mem = new MemberName(VarHandle.class, name, type, REF_invokeVirtual); 707 mem.flags |= mods; // it's not resolved, but add these modifiers anyway 708 assert(mem.isVarHandleMethodInvoke()) : mem; 709 return mem; 710 } 711 712 // bare-bones constructor; the JVM will fill it in 713 MemberName() { } 714 715 // locally useful cloner 716 @Override protected MemberName clone() { 717 try { 718 return (MemberName) super.clone(); 719 } catch (CloneNotSupportedException ex) { 720 throw newInternalError(ex); 721 } 722 } 723 724 /** Get the definition of this member name. 725 * This may be in a super-class of the declaring class of this member. 726 */ 727 public MemberName getDefinition() { 728 if (!isResolved()) throw new IllegalStateException("must be resolved: "+this); 729 if (isType()) return this; 730 MemberName res = this.clone(); 731 res.clazz = null; 732 res.type = null; 733 res.name = null; 734 res.resolution = res; 735 res.expandFromVM(); 736 assert(res.getName().equals(this.getName())); 737 return res; 738 } 739 740 @Override 741 @SuppressWarnings("deprecation") 742 public int hashCode() { 743 // Avoid autoboxing getReferenceKind(), since this is used early and will force 744 // early initialization of Byte$ByteCache 745 return Objects.hash(clazz, new Byte(getReferenceKind()), name, getType()); 746 } 747 748 @Override 749 public boolean equals(Object that) { 750 return (that instanceof MemberName && this.equals((MemberName)that)); 751 } 752 753 /** Decide if two member names have exactly the same symbolic content. 754 * Does not take into account any actual class members, so even if 755 * two member names resolve to the same actual member, they may 756 * be distinct references. 757 */ 758 public boolean equals(MemberName that) { 759 if (this == that) return true; 760 if (that == null) return false; 761 return this.clazz == that.clazz 762 && this.getReferenceKind() == that.getReferenceKind() 763 && Objects.equals(this.name, that.name) 764 && Objects.equals(this.getType(), that.getType()); 765 } 766 767 // Construction from symbolic parts, for queries: 768 /** Create a field or type name from the given components: 769 * Declaring class, name, type, reference kind. 770 * The declaring class may be supplied as null if this is to be a bare name and type. 771 * The resulting name will in an unresolved state. 772 */ 773 public MemberName(Class<?> defClass, String name, Class<?> type, byte refKind) { 774 init(defClass, name, type, flagsMods(IS_FIELD, 0, refKind)); 775 initResolved(false); 776 } 777 /** Create a method or constructor name from the given components: 778 * Declaring class, name, type, reference kind. 779 * It will be a constructor if and only if the name is {@code "<init>"}. 780 * The declaring class may be supplied as null if this is to be a bare name and type. 781 * The last argument is optional, a boolean which requests REF_invokeSpecial. 782 * The resulting name will in an unresolved state. 783 */ 784 public MemberName(Class<?> defClass, String name, MethodType type, byte refKind) { 785 int initFlags = (name != null && name.equals(CONSTRUCTOR_NAME) ? IS_CONSTRUCTOR : IS_METHOD); 786 init(defClass, name, type, flagsMods(initFlags, 0, refKind)); 787 initResolved(false); 788 } 789 /** Create a method, constructor, or field name from the given components: 790 * Reference kind, declaring class, name, type. 791 */ 792 public MemberName(byte refKind, Class<?> defClass, String name, Object type) { 793 int kindFlags; 794 if (MethodHandleNatives.refKindIsField(refKind)) { 795 kindFlags = IS_FIELD; 796 if (!(type instanceof Class)) 797 throw newIllegalArgumentException("not a field type"); 798 } else if (MethodHandleNatives.refKindIsMethod(refKind)) { 799 kindFlags = IS_METHOD; 800 if (!(type instanceof MethodType)) 801 throw newIllegalArgumentException("not a method type"); 802 } else if (refKind == REF_newInvokeSpecial) { 803 kindFlags = IS_CONSTRUCTOR; 804 if (!(type instanceof MethodType) || 805 !CONSTRUCTOR_NAME.equals(name)) 806 throw newIllegalArgumentException("not a constructor type or name"); 807 } else { 808 throw newIllegalArgumentException("bad reference kind "+refKind); 809 } 810 init(defClass, name, type, flagsMods(kindFlags, 0, refKind)); 811 initResolved(false); 812 } 813 /** Query whether this member name is resolved to a non-static, non-final method. 814 */ 815 public boolean hasReceiverTypeDispatch() { 816 return MethodHandleNatives.refKindDoesDispatch(getReferenceKind()); 817 } 818 819 /** Query whether this member name is resolved. 820 * A resolved member name is one for which the JVM has found 821 * a method, constructor, field, or type binding corresponding exactly to the name. 822 * (Document?) 823 */ 824 public boolean isResolved() { 825 return resolution == null; 826 } 827 828 void initResolved(boolean isResolved) { 829 assert(this.resolution == null); // not initialized yet! 830 if (!isResolved) 831 this.resolution = this; 832 assert(isResolved() == isResolved); 833 } 834 835 void checkForTypeAlias(Class<?> refc) { 836 if (isInvocable()) { 837 MethodType type; 838 if (this.type instanceof MethodType) 839 type = (MethodType) this.type; 840 else 841 this.type = type = getMethodType(); 842 if (type.erase() == type) return; 843 if (VerifyAccess.isTypeVisible(type, refc)) return; 844 throw new LinkageError("bad method type alias: "+type+" not visible from "+refc); 845 } else { 846 Class<?> type; 847 if (this.type instanceof Class<?>) 848 type = (Class<?>) this.type; 849 else 850 this.type = type = getFieldType(); 851 if (VerifyAccess.isTypeVisible(type, refc)) return; 852 throw new LinkageError("bad field type alias: "+type+" not visible from "+refc); 853 } 854 } 855 856 857 /** Produce a string form of this member name. 858 * For types, it is simply the type's own string (as reported by {@code toString}). 859 * For fields, it is {@code "DeclaringClass.name/type"}. 860 * For methods and constructors, it is {@code "DeclaringClass.name(ptype...)rtype"}. 861 * If the declaring class is null, the prefix {@code "DeclaringClass."} is omitted. 862 * If the member is unresolved, a prefix {@code "*."} is prepended. 863 */ 864 @SuppressWarnings("LocalVariableHidesMemberVariable") 865 @Override 866 public String toString() { 867 if (isType()) 868 return type.toString(); // class java.lang.String 869 // else it is a field, method, or constructor 870 StringBuilder buf = new StringBuilder(); 871 if (getDeclaringClass() != null) { 872 buf.append(getName(clazz)); 873 buf.append('.'); 874 } 875 String name = getName(); 876 buf.append(name == null ? "*" : name); 877 Object type = getType(); 878 if (!isInvocable()) { 879 buf.append('/'); 880 buf.append(type == null ? "*" : getName(type)); 881 } else { 882 buf.append(type == null ? "(*)*" : getName(type)); 883 } 884 byte refKind = getReferenceKind(); 885 if (refKind != REF_NONE) { 886 buf.append('/'); 887 buf.append(MethodHandleNatives.refKindName(refKind)); 888 } 889 //buf.append("#").append(System.identityHashCode(this)); 890 return buf.toString(); 891 } 892 private static String getName(Object obj) { 893 if (obj instanceof Class<?>) 894 return ((Class<?>)obj).getName(); 895 return String.valueOf(obj); 896 } 897 898 public IllegalAccessException makeAccessException(String message, Object from) { 899 message = message + ": "+ toString(); 900 if (from != null) { 901 if (from == MethodHandles.publicLookup()) { 902 message += ", from public Lookup"; 903 } else { 904 Module m; 905 if (from instanceof MethodHandles.Lookup) { 906 MethodHandles.Lookup lookup = (MethodHandles.Lookup)from; 907 m = lookup.lookupClass().getModule(); 908 } else { 909 m = from.getClass().getModule(); 910 } 911 message += ", from " + from + " (" + m + ")"; 912 } 913 } 914 return new IllegalAccessException(message); 915 } 916 private String message() { 917 if (isResolved()) 918 return "no access"; 919 else if (isConstructor()) 920 return "no such constructor"; 921 else if (isMethod()) 922 return "no such method"; 923 else 924 return "no such field"; 925 } 926 public ReflectiveOperationException makeAccessException() { 927 String message = message() + ": "+ toString(); 928 ReflectiveOperationException ex; 929 if (isResolved() || !(resolution instanceof NoSuchMethodError || 930 resolution instanceof NoSuchFieldError)) 931 ex = new IllegalAccessException(message); 932 else if (isConstructor()) 933 ex = new NoSuchMethodException(message); 934 else if (isMethod()) 935 ex = new NoSuchMethodException(message); 936 else 937 ex = new NoSuchFieldException(message); 938 if (resolution instanceof Throwable) 939 ex.initCause((Throwable) resolution); 940 return ex; 941 } 942 943 /** Actually making a query requires an access check. */ 944 /*non-public*/ static Factory getFactory() { 945 return Factory.INSTANCE; 946 } 947 /** A factory type for resolving member names with the help of the VM. 948 * TBD: Define access-safe public constructors for this factory. 949 */ 950 /*non-public*/ static class Factory { 951 private Factory() { } // singleton pattern 952 static Factory INSTANCE = new Factory(); 953 954 private static int ALLOWED_FLAGS = ALL_KINDS; 955 956 /// Queries 957 List<MemberName> getMembers(Class<?> defc, 958 String matchName, Object matchType, 959 int matchFlags, Class<?> lookupClass) { 960 matchFlags &= ALLOWED_FLAGS; 961 String matchSig = null; 962 if (matchType != null) { 963 matchSig = BytecodeDescriptor.unparse(matchType); 964 if (matchSig.startsWith("(")) 965 matchFlags &= ~(ALL_KINDS & ~IS_INVOCABLE); 966 else 967 matchFlags &= ~(ALL_KINDS & ~IS_FIELD); 968 } 969 final int BUF_MAX = 0x2000; 970 int len1 = matchName == null ? 10 : matchType == null ? 4 : 1; 971 MemberName[] buf = newMemberBuffer(len1); 972 int totalCount = 0; 973 ArrayList<MemberName[]> bufs = null; 974 int bufCount = 0; 975 for (;;) { 976 bufCount = MethodHandleNatives.getMembers(defc, 977 matchName, matchSig, matchFlags, 978 lookupClass, 979 totalCount, buf); 980 if (bufCount <= buf.length) { 981 if (bufCount < 0) bufCount = 0; 982 totalCount += bufCount; 983 break; 984 } 985 // JVM returned to us with an intentional overflow! 986 totalCount += buf.length; 987 int excess = bufCount - buf.length; 988 if (bufs == null) bufs = new ArrayList<>(1); 989 bufs.add(buf); 990 int len2 = buf.length; 991 len2 = Math.max(len2, excess); 992 len2 = Math.max(len2, totalCount / 4); 993 buf = newMemberBuffer(Math.min(BUF_MAX, len2)); 994 } 995 ArrayList<MemberName> result = new ArrayList<>(totalCount); 996 if (bufs != null) { 997 for (MemberName[] buf0 : bufs) { 998 Collections.addAll(result, buf0); 999 } 1000 } 1001 for (int i = 0; i < bufCount; i++) { 1002 result.add(buf[i]); 1003 } 1004 // Signature matching is not the same as type matching, since 1005 // one signature might correspond to several types. 1006 // So if matchType is a Class or MethodType, refilter the results. 1007 if (matchType != null && matchType != matchSig) { 1008 for (Iterator<MemberName> it = result.iterator(); it.hasNext();) { 1009 MemberName m = it.next(); 1010 if (!matchType.equals(m.getType())) 1011 it.remove(); 1012 } 1013 } 1014 return result; 1015 } 1016 /** Produce a resolved version of the given member. 1017 * Super types are searched (for inherited members) if {@code searchSupers} is true. 1018 * Access checking is performed on behalf of the given {@code lookupClass}. 1019 * If lookup fails or access is not permitted, null is returned. 1020 * Otherwise a fresh copy of the given member is returned, with modifier bits filled in. 1021 */ 1022 private MemberName resolve(byte refKind, MemberName ref, Class<?> lookupClass) { 1023 MemberName m = ref.clone(); // JVM will side-effect the ref 1024 assert(refKind == m.getReferenceKind()); 1025 try { 1026 // There are 4 entities in play here: 1027 // * LC: lookupClass 1028 // * REFC: symbolic reference class (MN.clazz before resolution); 1029 // * DEFC: resolved method holder (MN.clazz after resolution); 1030 // * PTYPES: parameter types (MN.type) 1031 // 1032 // What we care about when resolving a MemberName is consistency between DEFC and PTYPES. 1033 // We do type alias (TA) checks on DEFC to ensure that. DEFC is not known until the JVM 1034 // finishes the resolution, so do TA checks right after MHN.resolve() is over. 1035 // 1036 // All parameters passed by a caller are checked against MH type (PTYPES) on every invocation, 1037 // so it is safe to call a MH from any context. 1038 // 1039 // REFC view on PTYPES doesn't matter, since it is used only as a starting point for resolution and doesn't 1040 // participate in method selection. 1041 m = MethodHandleNatives.resolve(m, lookupClass); 1042 m.checkForTypeAlias(m.getDeclaringClass()); 1043 m.resolution = null; 1044 } catch (ClassNotFoundException | LinkageError ex) { 1045 // JVM reports that the "bytecode behavior" would get an error 1046 assert(!m.isResolved()); 1047 m.resolution = ex; 1048 return m; 1049 } 1050 assert(m.referenceKindIsConsistent()); 1051 m.initResolved(true); 1052 assert(m.vminfoIsConsistent()); 1053 return m; 1054 } 1055 /** Produce a resolved version of the given member. 1056 * Super types are searched (for inherited members) if {@code searchSupers} is true. 1057 * Access checking is performed on behalf of the given {@code lookupClass}. 1058 * If lookup fails or access is not permitted, a {@linkplain ReflectiveOperationException} is thrown. 1059 * Otherwise a fresh copy of the given member is returned, with modifier bits filled in. 1060 */ 1061 public 1062 <NoSuchMemberException extends ReflectiveOperationException> 1063 MemberName resolveOrFail(byte refKind, MemberName m, Class<?> lookupClass, 1064 Class<NoSuchMemberException> nsmClass) 1065 throws IllegalAccessException, NoSuchMemberException { 1066 MemberName result = resolve(refKind, m, lookupClass); 1067 if (result.isResolved()) 1068 return result; 1069 ReflectiveOperationException ex = result.makeAccessException(); 1070 if (ex instanceof IllegalAccessException) throw (IllegalAccessException) ex; 1071 throw nsmClass.cast(ex); 1072 } 1073 /** Produce a resolved version of the given member. 1074 * Super types are searched (for inherited members) if {@code searchSupers} is true. 1075 * Access checking is performed on behalf of the given {@code lookupClass}. 1076 * If lookup fails or access is not permitted, return null. 1077 * Otherwise a fresh copy of the given member is returned, with modifier bits filled in. 1078 */ 1079 public 1080 MemberName resolveOrNull(byte refKind, MemberName m, Class<?> lookupClass) { 1081 MemberName result = resolve(refKind, m, lookupClass); 1082 if (result.isResolved()) 1083 return result; 1084 return null; 1085 } 1086 /** Return a list of all methods defined by the given class. 1087 * Super types are searched (for inherited members) if {@code searchSupers} is true. 1088 * Access checking is performed on behalf of the given {@code lookupClass}. 1089 * Inaccessible members are not added to the last. 1090 */ 1091 public List<MemberName> getMethods(Class<?> defc, boolean searchSupers, 1092 Class<?> lookupClass) { 1093 return getMethods(defc, searchSupers, null, null, lookupClass); 1094 } 1095 /** Return a list of matching methods defined by the given class. 1096 * Super types are searched (for inherited members) if {@code searchSupers} is true. 1097 * Returned methods will match the name (if not null) and the type (if not null). 1098 * Access checking is performed on behalf of the given {@code lookupClass}. 1099 * Inaccessible members are not added to the last. 1100 */ 1101 public List<MemberName> getMethods(Class<?> defc, boolean searchSupers, 1102 String name, MethodType type, Class<?> lookupClass) { 1103 int matchFlags = IS_METHOD | (searchSupers ? SEARCH_ALL_SUPERS : 0); 1104 return getMembers(defc, name, type, matchFlags, lookupClass); 1105 } 1106 /** Return a list of all constructors defined by the given class. 1107 * Access checking is performed on behalf of the given {@code lookupClass}. 1108 * Inaccessible members are not added to the last. 1109 */ 1110 public List<MemberName> getConstructors(Class<?> defc, Class<?> lookupClass) { 1111 return getMembers(defc, null, null, IS_CONSTRUCTOR, lookupClass); 1112 } 1113 /** Return a list of all fields defined by the given class. 1114 * Super types are searched (for inherited members) if {@code searchSupers} is true. 1115 * Access checking is performed on behalf of the given {@code lookupClass}. 1116 * Inaccessible members are not added to the last. 1117 */ 1118 public List<MemberName> getFields(Class<?> defc, boolean searchSupers, 1119 Class<?> lookupClass) { 1120 return getFields(defc, searchSupers, null, null, lookupClass); 1121 } 1122 /** Return a list of all fields defined by the given class. 1123 * Super types are searched (for inherited members) if {@code searchSupers} is true. 1124 * Returned fields will match the name (if not null) and the type (if not null). 1125 * Access checking is performed on behalf of the given {@code lookupClass}. 1126 * Inaccessible members are not added to the last. 1127 */ 1128 public List<MemberName> getFields(Class<?> defc, boolean searchSupers, 1129 String name, Class<?> type, Class<?> lookupClass) { 1130 int matchFlags = IS_FIELD | (searchSupers ? SEARCH_ALL_SUPERS : 0); 1131 return getMembers(defc, name, type, matchFlags, lookupClass); 1132 } 1133 /** Return a list of all nested types defined by the given class. 1134 * Super types are searched (for inherited members) if {@code searchSupers} is true. 1135 * Access checking is performed on behalf of the given {@code lookupClass}. 1136 * Inaccessible members are not added to the last. 1137 */ 1138 public List<MemberName> getNestedTypes(Class<?> defc, boolean searchSupers, 1139 Class<?> lookupClass) { 1140 int matchFlags = IS_TYPE | (searchSupers ? SEARCH_ALL_SUPERS : 0); 1141 return getMembers(defc, null, null, matchFlags, lookupClass); 1142 } 1143 private static MemberName[] newMemberBuffer(int length) { 1144 MemberName[] buf = new MemberName[length]; 1145 // fill the buffer with dummy structs for the JVM to fill in 1146 for (int i = 0; i < length; i++) 1147 buf[i] = new MemberName(); 1148 return buf; 1149 } 1150 } 1151} 1152