1 /* 2 * Copyright (c) 2008, 2022, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package java.lang.invoke; 27 28 import jdk.internal.value.PrimitiveClass; 29 import sun.invoke.util.VerifyAccess; 30 31 import java.lang.reflect.Constructor; 32 import java.lang.reflect.Field; 33 import java.lang.reflect.Member; 34 import java.lang.reflect.Method; 35 import java.lang.reflect.Modifier; 36 import java.util.Objects; 37 38 import static java.lang.invoke.MethodHandleNatives.Constants.*; 39 import static java.lang.invoke.MethodHandleStatics.newIllegalArgumentException; 40 import static java.lang.invoke.MethodHandleStatics.newInternalError; 41 42 /** 43 * A {@code MemberName} is a compact symbolic datum which fully characterizes 44 * a method or field reference. 45 * A member name refers to a field, method, constructor, or member type. 46 * Every member name has a simple name (a string) and a type (either a Class or MethodType). 47 * A member name may also have a non-null declaring class, or it may be simply 48 * a naked name/type pair. 49 * A member name may also have non-zero modifier flags. 50 * Finally, a member name may be either resolved or unresolved. 51 * If it is resolved, the existence of the named member has been determined by the JVM. 52 * <p> 53 * Whether resolved or not, a member name provides no access rights or 54 * invocation capability to its possessor. It is merely a compact 55 * representation of all symbolic information necessary to link to 56 * and properly use the named member. 57 * <p> 58 * When resolved, a member name's internal implementation may include references to JVM metadata. 59 * This representation is stateless and only descriptive. 60 * It provides no private information and no capability to use the member. 61 * <p> 62 * By contrast, a {@linkplain java.lang.reflect.Method} contains fuller information 63 * about the internals of a method (except its bytecodes) and also 64 * allows invocation. A MemberName is much lighter than a Method, 65 * since it contains about 7 fields to the 16 of Method (plus its sub-arrays), 66 * and those seven fields omit much of the information in Method. 67 * @author jrose 68 */ 69 /*non-public*/ 70 final class ResolvedMethodName { 71 //@Injected JVM_Method* vmtarget; 72 //@Injected Class<?> vmholder; 73 } 74 75 /*non-public*/ 76 final class MemberName implements Member, Cloneable { 77 private Class<?> clazz; // class in which the member is defined 78 private String name; // may be null if not yet materialized 79 private Object type; // may be null if not yet materialized 80 private int flags; // modifier bits; see reflect.Modifier 81 private ResolvedMethodName method; // cached resolved method information 82 //@Injected intptr_t vmindex; // vtable index or offset of resolved member 83 Object resolution; // if null, this guy is resolved 84 85 /** Return the declaring class of this member. 86 * In the case of a bare name and type, the declaring class will be null. 87 */ 88 public Class<?> getDeclaringClass() { 89 return clazz; 90 } 91 92 /** Utility method producing the class loader of the declaring class. */ 93 public ClassLoader getClassLoader() { 94 return clazz.getClassLoader(); 95 } 96 97 /** Return the simple name of this member. 98 * For a type, it is the same as {@link Class#getSimpleName}. 99 * For a method or field, it is the simple name of the member. 100 * For an identity object constructor, it is {@code "<init>"}. 101 * For a value class static factory method, it is {@code "<vnew>"}. 102 */ 103 public String getName() { 104 if (name == null) { 105 expandFromVM(); 106 if (name == null) { 107 return null; 108 } 109 } 110 return name; 111 } 112 113 public MethodType getMethodOrFieldType() { 114 if (isInvocable()) 115 return getMethodType(); 116 if (isGetter()) 117 return MethodType.methodType(getFieldType()); 118 if (isSetter()) 119 return MethodType.methodType(void.class, getFieldType()); 120 throw new InternalError("not a method or field: "+this); 121 } 122 123 /** Return the declared type of this member, which 124 * must be a method or constructor. 125 */ 126 public MethodType getMethodType() { 127 if (type == null) { 128 expandFromVM(); 129 if (type == null) { 130 return null; 131 } 132 } 133 if (!isInvocable()) { 134 throw newIllegalArgumentException("not invocable, no method type"); 135 } 136 137 { 138 // Get a snapshot of type which doesn't get changed by racing threads. 139 final Object type = this.type; 140 if (type instanceof MethodType) { 141 return (MethodType) type; 142 } 143 } 144 145 // type is not a MethodType yet. Convert it thread-safely. 146 synchronized (this) { 147 if (type instanceof String sig) { 148 MethodType res = MethodType.fromDescriptor(sig, getClassLoader()); 149 type = res; 150 } else if (type instanceof Object[] typeInfo) { 151 Class<?>[] ptypes = (Class<?>[]) typeInfo[1]; 152 Class<?> rtype = (Class<?>) typeInfo[0]; 153 MethodType res = MethodType.methodType(rtype, ptypes, true); 154 type = res; 155 } 156 // Make sure type is a MethodType for racing threads. 157 assert type instanceof MethodType : "bad method type " + type; 158 } 159 return (MethodType) type; 160 } 161 162 /** Return the descriptor of this member, which 163 * must be a method or constructor. 164 */ 165 String getMethodDescriptor() { 166 if (type == null) { 167 expandFromVM(); 168 if (type == null) { 169 return null; 170 } 171 } 172 if (!isInvocable()) { 173 throw newIllegalArgumentException("not invocable, no method type"); 174 } 175 176 // Get a snapshot of type which doesn't get changed by racing threads. 177 final Object type = this.type; 178 if (type instanceof String) { 179 return (String) type; 180 } else { 181 return getMethodType().toMethodDescriptorString(); 182 } 183 } 184 185 /** Return the actual type under which this method or constructor must be invoked. 186 * For non-static methods or constructors, this is the type with a leading parameter, 187 * a reference to declaring class. For static methods, it is the same as the declared type. 188 */ 189 public MethodType getInvocationType() { 190 MethodType itype = getMethodOrFieldType(); 191 Class<?> c = PrimitiveClass.isPrimitiveClass(clazz) ? PrimitiveClass.asValueType(clazz) : clazz; 192 if (isObjectConstructor() && getReferenceKind() == REF_newInvokeSpecial) 193 return itype.changeReturnType(c); 194 if (!isStatic()) 195 return itype.insertParameterTypes(0, c); 196 return itype; 197 } 198 199 /** Return the declared type of this member, which 200 * must be a field or type. 201 * If it is a type member, that type itself is returned. 202 */ 203 public Class<?> getFieldType() { 204 if (type == null) { 205 expandFromVM(); 206 if (type == null) { 207 return null; 208 } 209 } 210 if (isInvocable()) { 211 throw newIllegalArgumentException("not a field or nested class, no simple type"); 212 } 213 214 { 215 // Get a snapshot of type which doesn't get changed by racing threads. 216 final Object type = this.type; 217 if (type instanceof Class<?>) { 218 return (Class<?>) type; 219 } 220 } 221 222 // type is not a Class yet. Convert it thread-safely. 223 synchronized (this) { 224 if (type instanceof String sig) { 225 MethodType mtype = MethodType.fromDescriptor("()"+sig, getClassLoader()); 226 Class<?> res = mtype.returnType(); 227 type = res; 228 } 229 // Make sure type is a Class for racing threads. 230 assert type instanceof Class<?> : "bad field type " + type; 231 } 232 return (Class<?>) type; 233 } 234 235 /** Utility method to produce either the method type or field type of this member. */ 236 public Object getType() { 237 return (isInvocable() ? getMethodType() : getFieldType()); 238 } 239 240 /** Return the modifier flags of this member. 241 * @see java.lang.reflect.Modifier 242 */ 243 public int getModifiers() { 244 return (flags & RECOGNIZED_MODIFIERS); 245 } 246 247 /** Return the reference kind of this member, or zero if none. 248 */ 249 public byte getReferenceKind() { 250 return (byte) ((flags >>> MN_REFERENCE_KIND_SHIFT) & MN_REFERENCE_KIND_MASK); 251 } 252 private boolean referenceKindIsConsistent() { 253 byte refKind = getReferenceKind(); 254 if (refKind == REF_NONE) return isType(); 255 if (isField()) { 256 assert(staticIsConsistent()); 257 assert(MethodHandleNatives.refKindIsField(refKind)); 258 } else if (isObjectConstructor()) { 259 assert(refKind == REF_newInvokeSpecial || refKind == REF_invokeSpecial); 260 } else if (isMethod()) { 261 assert(staticIsConsistent()); 262 assert(MethodHandleNatives.refKindIsMethod(refKind)); 263 if (clazz.isInterface()) 264 assert(refKind == REF_invokeInterface || 265 refKind == REF_invokeStatic || 266 refKind == REF_invokeSpecial || 267 refKind == REF_invokeVirtual && isObjectPublicMethod()); 268 } else { 269 assert(false); 270 } 271 return true; 272 } 273 private boolean isObjectPublicMethod() { 274 if (clazz == Object.class) return true; 275 MethodType mtype = getMethodType(); 276 if (name.equals("toString") && mtype.returnType() == String.class && mtype.parameterCount() == 0) 277 return true; 278 if (name.equals("hashCode") && mtype.returnType() == int.class && mtype.parameterCount() == 0) 279 return true; 280 if (name.equals("equals") && mtype.returnType() == boolean.class && mtype.parameterCount() == 1 && mtype.parameterType(0) == Object.class) 281 return true; 282 return false; 283 } 284 285 /*non-public*/ 286 boolean referenceKindIsConsistentWith(int originalRefKind) { 287 int refKind = getReferenceKind(); 288 if (refKind == originalRefKind) return true; 289 if (getClass().desiredAssertionStatus()) { 290 switch (originalRefKind) { 291 case REF_invokeInterface -> { 292 // Looking up an interface method, can get (e.g.) Object.hashCode 293 assert (refKind == REF_invokeVirtual || refKind == REF_invokeSpecial) : this; 294 } 295 case REF_invokeVirtual, REF_newInvokeSpecial -> { 296 // Looked up a virtual, can get (e.g.) final String.hashCode. 297 assert (refKind == REF_invokeSpecial) : this; 298 } 299 default -> { 300 assert (false) : this + " != " + MethodHandleNatives.refKindName((byte) originalRefKind); 301 } 302 } 303 } 304 return true; 305 } 306 private boolean staticIsConsistent() { 307 byte refKind = getReferenceKind(); 308 return MethodHandleNatives.refKindIsStatic(refKind) == isStatic() || getModifiers() == 0; 309 } 310 private boolean vminfoIsConsistent() { 311 byte refKind = getReferenceKind(); 312 assert(isResolved()); // else don't call 313 Object vminfo = MethodHandleNatives.getMemberVMInfo(this); 314 assert(vminfo instanceof Object[]); 315 long vmindex = (Long) ((Object[])vminfo)[0]; 316 Object vmtarget = ((Object[])vminfo)[1]; 317 if (MethodHandleNatives.refKindIsField(refKind)) { 318 assert(vmindex >= 0) : vmindex + ":" + this; 319 assert(vmtarget instanceof Class); 320 } else { 321 if (MethodHandleNatives.refKindDoesDispatch(refKind)) 322 assert(vmindex >= 0) : vmindex + ":" + this; 323 else 324 assert(vmindex < 0) : vmindex; 325 assert(vmtarget instanceof MemberName) : vmtarget + " in " + this; 326 } 327 return true; 328 } 329 330 private MemberName changeReferenceKind(byte refKind, byte oldKind) { 331 assert(getReferenceKind() == oldKind && MethodHandleNatives.refKindIsValid(refKind)); 332 flags += (((int)refKind - oldKind) << MN_REFERENCE_KIND_SHIFT); 333 return this; 334 } 335 336 private boolean matchingFlagsSet(int mask, int flags) { 337 return (this.flags & mask) == flags; 338 } 339 private boolean allFlagsSet(int flags) { 340 return (this.flags & flags) == flags; 341 } 342 private boolean anyFlagSet(int flags) { 343 return (this.flags & flags) != 0; 344 } 345 346 /** Utility method to query if this member is a method handle invocation (invoke or invokeExact). 347 */ 348 public boolean isMethodHandleInvoke() { 349 final int bits = MH_INVOKE_MODS &~ Modifier.PUBLIC; 350 final int negs = Modifier.STATIC; 351 if (matchingFlagsSet(bits | negs, bits) && clazz == MethodHandle.class) { 352 return isMethodHandleInvokeName(name); 353 } 354 return false; 355 } 356 public static boolean isMethodHandleInvokeName(String name) { 357 return switch (name) { 358 case "invoke", "invokeExact" -> true; 359 default -> false; 360 }; 361 } 362 public boolean isVarHandleMethodInvoke() { 363 final int bits = MH_INVOKE_MODS &~ Modifier.PUBLIC; 364 final int negs = Modifier.STATIC; 365 if (matchingFlagsSet(bits | negs, bits) && clazz == VarHandle.class) { 366 return isVarHandleMethodInvokeName(name); 367 } 368 return false; 369 } 370 public static boolean isVarHandleMethodInvokeName(String name) { 371 try { 372 VarHandle.AccessMode.valueFromMethodName(name); 373 return true; 374 } catch (IllegalArgumentException e) { 375 return false; 376 } 377 } 378 private static final int MH_INVOKE_MODS = Modifier.NATIVE | Modifier.FINAL | Modifier.PUBLIC; 379 380 /** Utility method to query the modifier flags of this member. */ 381 public boolean isStatic() { 382 return Modifier.isStatic(flags); 383 } 384 /** Utility method to query the modifier flags of this member. */ 385 public boolean isPublic() { 386 return Modifier.isPublic(flags); 387 } 388 /** Utility method to query the modifier flags of this member. */ 389 public boolean isPrivate() { 390 return Modifier.isPrivate(flags); 391 } 392 /** Utility method to query the modifier flags of this member. */ 393 public boolean isProtected() { 394 return Modifier.isProtected(flags); 395 } 396 /** Utility method to query the modifier flags of this member. */ 397 public boolean isFinal() { 398 // all fields declared in a value type are effectively final 399 assert(!clazz.isValue() || !isField() || Modifier.isFinal(flags)); 400 return Modifier.isFinal(flags); 401 } 402 /** Utility method to query whether this member or its defining class is final. */ 403 public boolean canBeStaticallyBound() { 404 return Modifier.isFinal(flags | clazz.getModifiers()); 405 } 406 /** Utility method to query the modifier flags of this member. */ 407 public boolean isVolatile() { 408 return Modifier.isVolatile(flags); 409 } 410 /** Utility method to query the modifier flags of this member. */ 411 public boolean isAbstract() { 412 return Modifier.isAbstract(flags); 413 } 414 /** Utility method to query the modifier flags of this member. */ 415 public boolean isNative() { 416 return Modifier.isNative(flags); 417 } 418 // let the rest (native, volatile, transient, etc.) be tested via Modifier.isFoo 419 420 // unofficial modifier flags, used by HotSpot: 421 static final int BRIDGE = 0x00000040; 422 static final int VARARGS = 0x00000080; 423 static final int SYNTHETIC = 0x00001000; 424 static final int ANNOTATION = 0x00002000; 425 static final int ENUM = 0x00004000; 426 427 /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */ 428 public boolean isBridge() { 429 return allFlagsSet(IS_METHOD | BRIDGE); 430 } 431 /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */ 432 public boolean isVarargs() { 433 return allFlagsSet(VARARGS) && isInvocable(); 434 } 435 /** Utility method to query the modifier flags of this member; returns false if the member is not a method. */ 436 public boolean isSynthetic() { 437 return allFlagsSet(SYNTHETIC); 438 } 439 440 /** Query whether this member is a flattened field */ 441 public boolean isFlattened() { return (flags & MN_FLATTENED) == MN_FLATTENED; } 442 443 /** Query whether this member is a field of a primitive class. */ 444 public boolean isInlineableField() { 445 if (isField()) { 446 Class<?> type = getFieldType(); 447 return PrimitiveClass.isPrimitiveValueType(type) || (type.isValue() && !PrimitiveClass.isPrimitiveClass(type)); 448 } 449 return false; 450 } 451 452 static final String CONSTRUCTOR_NAME = "<init>"; 453 static final String VALUE_FACTORY_NAME = "<vnew>"; // the ever-popular 454 455 // modifiers exported by the JVM: 456 static final int RECOGNIZED_MODIFIERS = 0xFFFF; 457 458 // private flags, not part of RECOGNIZED_MODIFIERS: 459 static final int 460 IS_METHOD = MN_IS_METHOD, // method (not object constructor) 461 IS_OBJECT_CONSTRUCTOR = MN_IS_OBJECT_CONSTRUCTOR, // object constructor 462 IS_FIELD = MN_IS_FIELD, // field 463 IS_TYPE = MN_IS_TYPE, // nested type 464 CALLER_SENSITIVE = MN_CALLER_SENSITIVE, // @CallerSensitive annotation detected 465 TRUSTED_FINAL = MN_TRUSTED_FINAL; // trusted final field 466 467 static final int ALL_ACCESS = Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED; 468 static final int ALL_KINDS = IS_METHOD | IS_OBJECT_CONSTRUCTOR | IS_FIELD | IS_TYPE; 469 static final int IS_INVOCABLE = IS_METHOD | IS_OBJECT_CONSTRUCTOR; 470 471 /** Utility method to query whether this member is a method or constructor. */ 472 public boolean isInvocable() { 473 return anyFlagSet(IS_INVOCABLE); 474 } 475 /** Query whether this member is a method. */ 476 public boolean isMethod() { 477 return allFlagsSet(IS_METHOD); 478 } 479 /** Query whether this member is a constructor. */ 480 public boolean isObjectConstructor() { 481 return allFlagsSet(IS_OBJECT_CONSTRUCTOR); 482 } 483 /** Query whether this member is an object constructor or static <init> factory */ 484 public boolean isStaticValueFactoryMethod() { 485 return VALUE_FACTORY_NAME.equals(name) && isMethod(); 486 } 487 488 /** Query whether this member is a field. */ 489 public boolean isField() { 490 return allFlagsSet(IS_FIELD); 491 } 492 /** Query whether this member is a type. */ 493 public boolean isType() { 494 return allFlagsSet(IS_TYPE); 495 } 496 /** Utility method to query whether this member is neither public, private, nor protected. */ 497 public boolean isPackage() { 498 return !anyFlagSet(ALL_ACCESS); 499 } 500 /** Query whether this member has a CallerSensitive annotation. */ 501 public boolean isCallerSensitive() { 502 return allFlagsSet(CALLER_SENSITIVE); 503 } 504 /** Query whether this member is a trusted final field. */ 505 public boolean isTrustedFinalField() { 506 return allFlagsSet(TRUSTED_FINAL | IS_FIELD); 507 } 508 509 /** 510 * Check if MemberName is a call to a method named {@code name} in class {@code declaredClass}. 511 */ 512 public boolean refersTo(Class<?> declc, String n) { 513 return clazz == declc && getName().equals(n); 514 } 515 516 /** Initialize a query. It is not resolved. */ 517 private void init(Class<?> defClass, String name, Object type, int flags) { 518 // defining class is allowed to be null (for a naked name/type pair) 519 //name.toString(); // null check 520 //type.equals(type); // null check 521 // fill in fields: 522 this.clazz = defClass; 523 this.name = name; 524 this.type = type; 525 this.flags = flags; 526 assert(anyFlagSet(ALL_KINDS) && this.resolution == null); // nobody should have touched this yet 527 //assert(referenceKindIsConsistent()); // do this after resolution 528 } 529 530 /** 531 * Calls down to the VM to fill in the fields. This method is 532 * synchronized to avoid racing calls. 533 */ 534 private void expandFromVM() { 535 if (type != null) { 536 return; 537 } 538 if (!isResolved()) { 539 return; 540 } 541 MethodHandleNatives.expand(this); 542 } 543 544 // Capturing information from the Core Reflection API: 545 private static int flagsMods(int flags, int mods, byte refKind) { 546 assert((flags & RECOGNIZED_MODIFIERS) == 0 547 && (mods & ~RECOGNIZED_MODIFIERS) == 0 548 && (refKind & ~MN_REFERENCE_KIND_MASK) == 0); 549 return flags | mods | (refKind << MN_REFERENCE_KIND_SHIFT); 550 } 551 /** Create a name for the given reflected method. The resulting name will be in a resolved state. */ 552 public MemberName(Method m) { 553 this(m, false); 554 } 555 @SuppressWarnings("LeakingThisInConstructor") 556 public MemberName(Method m, boolean wantSpecial) { 557 Objects.requireNonNull(m); 558 // fill in vmtarget, vmindex while we have m in hand: 559 MethodHandleNatives.init(this, m); 560 if (clazz == null) { // MHN.init failed 561 if (m.getDeclaringClass() == MethodHandle.class && 562 isMethodHandleInvokeName(m.getName())) { 563 // The JVM did not reify this signature-polymorphic instance. 564 // Need a special case here. 565 // See comments on MethodHandleNatives.linkMethod. 566 MethodType type = MethodType.methodType(m.getReturnType(), m.getParameterTypes()); 567 int flags = flagsMods(IS_METHOD, m.getModifiers(), REF_invokeVirtual); 568 init(MethodHandle.class, m.getName(), type, flags); 569 if (isMethodHandleInvoke()) 570 return; 571 } 572 if (m.getDeclaringClass() == VarHandle.class && 573 isVarHandleMethodInvokeName(m.getName())) { 574 // The JVM did not reify this signature-polymorphic instance. 575 // Need a special case here. 576 // See comments on MethodHandleNatives.linkMethod. 577 MethodType type = MethodType.methodType(m.getReturnType(), m.getParameterTypes()); 578 int flags = flagsMods(IS_METHOD, m.getModifiers(), REF_invokeVirtual); 579 init(VarHandle.class, m.getName(), type, flags); 580 if (isVarHandleMethodInvoke()) 581 return; 582 } 583 throw new LinkageError(m.toString()); 584 } 585 assert(isResolved()); 586 this.name = m.getName(); 587 if (this.type == null) 588 this.type = new Object[] { m.getReturnType(), m.getParameterTypes() }; 589 if (wantSpecial) { 590 if (isAbstract()) 591 throw new AbstractMethodError(this.toString()); 592 if (getReferenceKind() == REF_invokeVirtual) 593 changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual); 594 else if (getReferenceKind() == REF_invokeInterface) 595 // invokeSpecial on a default method 596 changeReferenceKind(REF_invokeSpecial, REF_invokeInterface); 597 } 598 } 599 public MemberName asSpecial() { 600 switch (getReferenceKind()) { 601 case REF_invokeSpecial: return this; 602 case REF_invokeVirtual: return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual); 603 case REF_invokeInterface: return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeInterface); 604 case REF_newInvokeSpecial: return clone().changeReferenceKind(REF_invokeSpecial, REF_newInvokeSpecial); 605 } 606 throw new IllegalArgumentException(this.toString()); 607 } 608 /** If this MN is not REF_newInvokeSpecial, return a clone with that ref. kind. 609 * In that case it must already be REF_invokeSpecial. 610 */ 611 public MemberName asObjectConstructor() { 612 switch (getReferenceKind()) { 613 case REF_invokeSpecial: return clone().changeReferenceKind(REF_newInvokeSpecial, REF_invokeSpecial); 614 case REF_newInvokeSpecial: return this; 615 } 616 throw new IllegalArgumentException(this.toString()); 617 } 618 /** If this MN is a REF_invokeSpecial, return a clone with the "normal" kind 619 * REF_invokeVirtual; also switch either to REF_invokeInterface if clazz.isInterface. 620 * The end result is to get a fully virtualized version of the MN. 621 * (Note that resolving in the JVM will sometimes devirtualize, changing 622 * REF_invokeVirtual of a final to REF_invokeSpecial, and REF_invokeInterface 623 * in some corner cases to either of the previous two; this transform 624 * undoes that change under the assumption that it occurred.) 625 */ 626 public MemberName asNormalOriginal() { 627 byte refKind = getReferenceKind(); 628 byte newRefKind = switch (refKind) { 629 case REF_invokeInterface, 630 REF_invokeVirtual, 631 REF_invokeSpecial -> clazz.isInterface() ? REF_invokeInterface : REF_invokeVirtual; 632 default -> refKind; 633 }; 634 if (newRefKind == refKind) 635 return this; 636 MemberName result = clone().changeReferenceKind(newRefKind, refKind); 637 assert(this.referenceKindIsConsistentWith(result.getReferenceKind())); 638 return result; 639 } 640 /** Create a name for the given reflected constructor. The resulting name will be in a resolved state. */ 641 @SuppressWarnings("LeakingThisInConstructor") 642 public MemberName(Constructor<?> ctor) { 643 Objects.requireNonNull(ctor); 644 // fill in vmtarget, vmindex while we have ctor in hand: 645 MethodHandleNatives.init(this, ctor); 646 assert(isResolved() && this.clazz != null); 647 this.name = this.clazz.isValue() ? VALUE_FACTORY_NAME : CONSTRUCTOR_NAME; 648 if (this.type == null) { 649 Class<?> rtype = void.class; 650 if (isStatic()) { // a value class static factory, not a true constructor 651 rtype = getDeclaringClass(); 652 } 653 this.type = new Object[] { rtype, ctor.getParameterTypes() }; 654 } 655 } 656 /** Create a name for the given reflected field. The resulting name will be in a resolved state. 657 */ 658 public MemberName(Field fld) { 659 this(fld, false); 660 } 661 static { 662 // the following MemberName constructor relies on these ranges matching up 663 assert((REF_putStatic - REF_getStatic) == (REF_putField - REF_getField)); 664 } 665 @SuppressWarnings("LeakingThisInConstructor") 666 public MemberName(Field fld, boolean makeSetter) { 667 Objects.requireNonNull(fld); 668 // fill in vmtarget, vmindex while we have fld in hand: 669 MethodHandleNatives.init(this, fld); 670 assert(isResolved() && this.clazz != null); 671 this.name = fld.getName(); 672 this.type = fld.getType(); 673 byte refKind = this.getReferenceKind(); 674 assert(refKind == (isStatic() ? REF_getStatic : REF_getField)); 675 if (makeSetter) { 676 changeReferenceKind((byte)(refKind + (REF_putStatic - REF_getStatic)), refKind); 677 } 678 } 679 public boolean isGetter() { 680 return MethodHandleNatives.refKindIsGetter(getReferenceKind()); 681 } 682 public boolean isSetter() { 683 return MethodHandleNatives.refKindIsSetter(getReferenceKind()); 684 } 685 686 /** Create a name for the given class. The resulting name will be in a resolved state. */ 687 public MemberName(Class<?> type) { 688 init(type.getDeclaringClass(), type.getSimpleName(), type, 689 flagsMods(IS_TYPE, type.getModifiers(), REF_NONE)); 690 initResolved(true); 691 } 692 693 /** 694 * Create a name for a signature-polymorphic invoker. 695 * This is a placeholder for a signature-polymorphic instance 696 * (of MH.invokeExact, etc.) that the JVM does not reify. 697 * See comments on {@link MethodHandleNatives#linkMethod}. 698 */ 699 static MemberName makeMethodHandleInvoke(String name, MethodType type) { 700 return makeMethodHandleInvoke(name, type, MH_INVOKE_MODS | SYNTHETIC); 701 } 702 static MemberName makeMethodHandleInvoke(String name, MethodType type, int mods) { 703 MemberName mem = new MemberName(MethodHandle.class, name, type, REF_invokeVirtual); 704 mem.flags |= mods; // it's not resolved, but add these modifiers anyway 705 assert(mem.isMethodHandleInvoke()) : mem; 706 return mem; 707 } 708 709 static MemberName makeVarHandleMethodInvoke(String name, MethodType type) { 710 return makeVarHandleMethodInvoke(name, type, MH_INVOKE_MODS | SYNTHETIC); 711 } 712 static MemberName makeVarHandleMethodInvoke(String name, MethodType type, int mods) { 713 MemberName mem = new MemberName(VarHandle.class, name, type, REF_invokeVirtual); 714 mem.flags |= mods; // it's not resolved, but add these modifiers anyway 715 assert(mem.isVarHandleMethodInvoke()) : mem; 716 return mem; 717 } 718 719 // bare-bones constructor; the JVM will fill it in 720 MemberName() { } 721 722 // locally useful cloner 723 @Override protected MemberName clone() { 724 try { 725 return (MemberName) super.clone(); 726 } catch (CloneNotSupportedException ex) { 727 throw newInternalError(ex); 728 } 729 } 730 731 /** Get the definition of this member name. 732 * This may be in a super-class of the declaring class of this member. 733 */ 734 public MemberName getDefinition() { 735 if (!isResolved()) throw new IllegalStateException("must be resolved: "+this); 736 if (isType()) return this; 737 MemberName res = this.clone(); 738 res.clazz = null; 739 res.type = null; 740 res.name = null; 741 res.resolution = res; 742 res.expandFromVM(); 743 assert(res.getName().equals(this.getName())); 744 return res; 745 } 746 747 @Override 748 @SuppressWarnings({"deprecation", "removal"}) 749 public int hashCode() { 750 // Avoid autoboxing getReferenceKind(), since this is used early and will force 751 // early initialization of Byte$ByteCache 752 return Objects.hash(clazz, new Byte(getReferenceKind()), name, getType()); 753 } 754 755 @Override 756 public boolean equals(Object that) { 757 return (that instanceof MemberName && this.equals((MemberName)that)); 758 } 759 760 /** Decide if two member names have exactly the same symbolic content. 761 * Does not take into account any actual class members, so even if 762 * two member names resolve to the same actual member, they may 763 * be distinct references. 764 */ 765 public boolean equals(MemberName that) { 766 if (this == that) return true; 767 if (that == null) return false; 768 return this.clazz == that.clazz 769 && this.getReferenceKind() == that.getReferenceKind() 770 && Objects.equals(this.name, that.name) 771 && Objects.equals(this.getType(), that.getType()); 772 } 773 774 // Construction from symbolic parts, for queries: 775 /** Create a field or type name from the given components: 776 * Declaring class, name, type, reference kind. 777 * The declaring class may be supplied as null if this is to be a bare name and type. 778 * The resulting name will in an unresolved state. 779 */ 780 public MemberName(Class<?> defClass, String name, Class<?> type, byte refKind) { 781 init(defClass, name, type, flagsMods(IS_FIELD, 0, refKind)); 782 initResolved(false); 783 } 784 /** Create a method or constructor name from the given components: 785 * Declaring class, name, type, reference kind. 786 * It will be an object constructor if and only if the name is {@code "<init>"}. 787 * It will be a value class instance factory method if and only if the name is {@code "<vnew>"}. 788 * The declaring class may be supplied as null if this is to be a bare name and type. 789 * The last argument is optional, a boolean which requests REF_invokeSpecial. 790 * The resulting name will in an unresolved state. 791 */ 792 public MemberName(Class<?> defClass, String name, MethodType type, byte refKind) { 793 int initFlags = CONSTRUCTOR_NAME.equals(name) ? IS_OBJECT_CONSTRUCTOR : IS_METHOD; 794 init(defClass, name, type, flagsMods(initFlags, 0, refKind)); 795 initResolved(false); 796 } 797 /** Create a method, constructor, or field name from the given components: 798 * Reference kind, declaring class, name, type. 799 */ 800 public MemberName(byte refKind, Class<?> defClass, String name, Object type) { 801 int kindFlags; 802 if (MethodHandleNatives.refKindIsField(refKind)) { 803 kindFlags = IS_FIELD; 804 if (!(type instanceof Class)) 805 throw newIllegalArgumentException("not a field type"); 806 } else if (MethodHandleNatives.refKindIsMethod(refKind)) { 807 kindFlags = IS_METHOD; 808 if (!(type instanceof MethodType)) 809 throw newIllegalArgumentException("not a method type"); 810 } else if (refKind == REF_newInvokeSpecial) { 811 kindFlags = IS_OBJECT_CONSTRUCTOR; 812 if (!(type instanceof MethodType) || 813 !CONSTRUCTOR_NAME.equals(name)) 814 throw newIllegalArgumentException("not a constructor type or name"); 815 } else { 816 throw newIllegalArgumentException("bad reference kind "+refKind); 817 } 818 init(defClass, name, type, flagsMods(kindFlags, 0, refKind)); 819 initResolved(false); 820 } 821 822 /** Query whether this member name is resolved. 823 * A resolved member name is one for which the JVM has found 824 * a method, constructor, field, or type binding corresponding exactly to the name. 825 * (Document?) 826 */ 827 public boolean isResolved() { 828 return resolution == null; 829 } 830 831 void initResolved(boolean isResolved) { 832 assert(this.resolution == null); // not initialized yet! 833 if (!isResolved) 834 this.resolution = this; 835 assert(isResolved() == isResolved); 836 } 837 838 void checkForTypeAlias(Class<?> refc) { 839 if (isInvocable()) { 840 MethodType type; 841 if (this.type instanceof MethodType) 842 type = (MethodType) this.type; 843 else 844 this.type = type = getMethodType(); 845 if (type.erase() == type) return; 846 if (VerifyAccess.isTypeVisible(type, refc)) return; 847 throw new LinkageError("bad method type alias: "+type+" not visible from "+refc); 848 } else { 849 Class<?> type; 850 if (this.type instanceof Class<?>) 851 type = (Class<?>) this.type; 852 else 853 this.type = type = getFieldType(); 854 if (VerifyAccess.isTypeVisible(type, refc)) return; 855 throw new LinkageError("bad field type alias: "+type+" not visible from "+refc); 856 } 857 } 858 859 860 /** Produce a string form of this member name. 861 * For types, it is simply the type's own string (as reported by {@code toString}). 862 * For fields, it is {@code "DeclaringClass.name/type"}. 863 * For methods and constructors, it is {@code "DeclaringClass.name(ptype...)rtype"}. 864 * If the declaring class is null, the prefix {@code "DeclaringClass."} is omitted. 865 * If the member is unresolved, a prefix {@code "*."} is prepended. 866 */ 867 @SuppressWarnings("LocalVariableHidesMemberVariable") 868 @Override 869 public String toString() { 870 if (isType()) 871 return type.toString(); // class java.lang.String 872 // else it is a field, method, or constructor 873 StringBuilder buf = new StringBuilder(); 874 if (getDeclaringClass() != null) { 875 buf.append(getName(clazz)); 876 buf.append('.'); 877 } 878 String name = this.name; // avoid expanding from VM 879 buf.append(name == null ? "*" : name); 880 Object type = this.type; // avoid expanding from VM 881 if (!isInvocable()) { 882 buf.append('/'); 883 buf.append(type == null ? "*" : getName(type)); 884 } else { 885 buf.append(type == null ? "(*)*" : getName(type)); 886 } 887 byte refKind = getReferenceKind(); 888 if (refKind != REF_NONE) { 889 buf.append('/'); 890 buf.append(MethodHandleNatives.refKindName(refKind)); 891 } 892 //buf.append("#").append(System.identityHashCode(this)); 893 return buf.toString(); 894 } 895 private static String getName(Object obj) { 896 if (obj instanceof Class<?>) 897 return ((Class<?>)obj).getName(); 898 return String.valueOf(obj); 899 } 900 901 public IllegalAccessException makeAccessException(String message, Object from) { 902 message = message + ": " + this; 903 if (from != null) { 904 if (from == MethodHandles.publicLookup()) { 905 message += ", from public Lookup"; 906 } else { 907 Module m; 908 Class<?> plc; 909 if (from instanceof MethodHandles.Lookup lookup) { 910 from = lookup.lookupClass(); 911 m = lookup.lookupClass().getModule(); 912 plc = lookup.previousLookupClass(); 913 } else { 914 m = ((Class<?>)from).getModule(); 915 plc = null; 916 } 917 message += ", from " + from + " (" + m + ")"; 918 if (plc != null) { 919 message += ", previous lookup " + 920 plc.getName() + " (" + plc.getModule() + ")"; 921 } 922 } 923 } 924 return new IllegalAccessException(message); 925 } 926 private String message() { 927 if (isResolved()) 928 return "no access"; 929 else if (isObjectConstructor()) 930 return "no such constructor"; 931 else if (isMethod()) 932 return "no such method"; 933 else 934 return "no such field"; 935 } 936 public ReflectiveOperationException makeAccessException() { 937 String message = message() + ": " + this; 938 ReflectiveOperationException ex; 939 if (isResolved() || !(resolution instanceof NoSuchMethodError || 940 resolution instanceof NoSuchFieldError)) 941 ex = new IllegalAccessException(message); 942 else if (isObjectConstructor()) 943 ex = new NoSuchMethodException(message); 944 else if (isMethod()) 945 ex = new NoSuchMethodException(message); 946 else 947 ex = new NoSuchFieldException(message); 948 if (resolution instanceof Throwable) 949 ex.initCause((Throwable) resolution); 950 return ex; 951 } 952 953 /** Actually making a query requires an access check. */ 954 /*non-public*/ 955 static Factory getFactory() { 956 return Factory.INSTANCE; 957 } 958 /** A factory type for resolving member names with the help of the VM. 959 * TBD: Define access-safe public constructors for this factory. 960 */ 961 /*non-public*/ 962 static class Factory { 963 private Factory() { } // singleton pattern 964 static final Factory INSTANCE = new Factory(); 965 966 /** Produce a resolved version of the given member. 967 * Super types are searched (for inherited members) if {@code searchSupers} is true. 968 * Access checking is performed on behalf of the given {@code lookupClass}. 969 * If lookup fails or access is not permitted, null is returned. 970 * Otherwise a fresh copy of the given member is returned, with modifier bits filled in. 971 */ 972 private MemberName resolve(byte refKind, MemberName ref, Class<?> lookupClass, int allowedModes, 973 boolean speculativeResolve) { 974 MemberName m = ref.clone(); // JVM will side-effect the ref 975 assert(refKind == m.getReferenceKind()); 976 try { 977 // There are 4 entities in play here: 978 // * LC: lookupClass 979 // * REFC: symbolic reference class (MN.clazz before resolution); 980 // * DEFC: resolved method holder (MN.clazz after resolution); 981 // * PTYPES: parameter types (MN.type) 982 // 983 // What we care about when resolving a MemberName is consistency between DEFC and PTYPES. 984 // We do type alias (TA) checks on DEFC to ensure that. DEFC is not known until the JVM 985 // finishes the resolution, so do TA checks right after MHN.resolve() is over. 986 // 987 // All parameters passed by a caller are checked against MH type (PTYPES) on every invocation, 988 // so it is safe to call a MH from any context. 989 // 990 // REFC view on PTYPES doesn't matter, since it is used only as a starting point for resolution and doesn't 991 // participate in method selection. 992 m = MethodHandleNatives.resolve(m, lookupClass, allowedModes, speculativeResolve); 993 if (m == null && speculativeResolve) { 994 return null; 995 } 996 m.checkForTypeAlias(m.getDeclaringClass()); 997 m.resolution = null; 998 } catch (ClassNotFoundException | LinkageError ex) { 999 // JVM reports that the "bytecode behavior" would get an error 1000 assert(!m.isResolved()); 1001 m.resolution = ex; 1002 return m; 1003 } 1004 assert(m.referenceKindIsConsistent()); 1005 m.initResolved(true); 1006 assert(m.vminfoIsConsistent()); 1007 return m; 1008 } 1009 /** Produce a resolved version of the given member. 1010 * Super types are searched (for inherited members) if {@code searchSupers} is true. 1011 * Access checking is performed on behalf of the given {@code lookupClass}. 1012 * If lookup fails or access is not permitted, a {@linkplain ReflectiveOperationException} is thrown. 1013 * Otherwise a fresh copy of the given member is returned, with modifier bits filled in. 1014 */ 1015 public <NoSuchMemberException extends ReflectiveOperationException> 1016 MemberName resolveOrFail(byte refKind, MemberName m, 1017 Class<?> lookupClass, int allowedModes, 1018 Class<NoSuchMemberException> nsmClass) 1019 throws IllegalAccessException, NoSuchMemberException { 1020 assert lookupClass != null || allowedModes == LM_TRUSTED; 1021 MemberName result = resolve(refKind, m, lookupClass, allowedModes, false); 1022 if (result.isResolved()) 1023 return result; 1024 ReflectiveOperationException ex = result.makeAccessException(); 1025 if (ex instanceof IllegalAccessException) throw (IllegalAccessException) ex; 1026 throw nsmClass.cast(ex); 1027 } 1028 /** Produce a resolved version of the given member. 1029 * Super types are searched (for inherited members) if {@code searchSupers} is true. 1030 * Access checking is performed on behalf of the given {@code lookupClass}. 1031 * If lookup fails or access is not permitted, return null. 1032 * Otherwise a fresh copy of the given member is returned, with modifier bits filled in. 1033 */ 1034 public MemberName resolveOrNull(byte refKind, MemberName m, Class<?> lookupClass, int allowedModes) { 1035 assert lookupClass != null || allowedModes == LM_TRUSTED; 1036 MemberName result = resolve(refKind, m, lookupClass, allowedModes, true); 1037 if (result != null && result.isResolved()) 1038 return result; 1039 return null; 1040 } 1041 } 1042 }