1 /* 2 * Copyright (c) 2010, 2013, 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 jdk.nashorn.internal.runtime.linker; 27 28 import static jdk.internal.org.objectweb.asm.Opcodes.ACC_FINAL; 29 import static jdk.internal.org.objectweb.asm.Opcodes.ACC_PRIVATE; 30 import static jdk.internal.org.objectweb.asm.Opcodes.ACC_PUBLIC; 31 import static jdk.internal.org.objectweb.asm.Opcodes.ACC_STATIC; 32 import static jdk.internal.org.objectweb.asm.Opcodes.ACC_SUPER; 33 import static jdk.internal.org.objectweb.asm.Opcodes.ACC_VARARGS; 34 import static jdk.internal.org.objectweb.asm.Opcodes.ACONST_NULL; 35 import static jdk.internal.org.objectweb.asm.Opcodes.ALOAD; 36 import static jdk.internal.org.objectweb.asm.Opcodes.ASTORE; 37 import static jdk.internal.org.objectweb.asm.Opcodes.DUP; 38 import static jdk.internal.org.objectweb.asm.Opcodes.IFNONNULL; 39 import static jdk.internal.org.objectweb.asm.Opcodes.ILOAD; 40 import static jdk.internal.org.objectweb.asm.Opcodes.ISTORE; 41 import static jdk.internal.org.objectweb.asm.Opcodes.POP; 42 import static jdk.internal.org.objectweb.asm.Opcodes.RETURN; 43 import static jdk.nashorn.internal.lookup.Lookup.MH; 44 import static jdk.nashorn.internal.runtime.linker.AdaptationResult.Outcome.ERROR_NO_ACCESSIBLE_CONSTRUCTOR; 45 46 import java.lang.invoke.MethodHandle; 47 import java.lang.invoke.MethodType; 48 import java.lang.reflect.AccessibleObject; 49 import java.lang.reflect.Constructor; 50 import java.lang.reflect.Method; 51 import java.lang.reflect.Modifier; 52 import java.security.AccessControlContext; 53 import java.security.AccessController; 54 import java.security.PrivilegedAction; 55 import java.util.Arrays; 56 import java.util.Collection; 57 import java.util.HashSet; 58 import java.util.Iterator; 59 import java.util.List; 60 import java.util.Set; 61 import jdk.internal.org.objectweb.asm.ClassWriter; 62 import jdk.internal.org.objectweb.asm.Handle; 63 import jdk.internal.org.objectweb.asm.Label; 64 import jdk.internal.org.objectweb.asm.Opcodes; 65 import jdk.internal.org.objectweb.asm.Type; 66 import jdk.internal.org.objectweb.asm.commons.InstructionAdapter; 67 import jdk.nashorn.internal.runtime.Context; 68 import jdk.nashorn.internal.runtime.ScriptFunction; 69 import jdk.nashorn.internal.runtime.ScriptObject; 70 import jdk.nashorn.internal.runtime.linker.AdaptationResult.Outcome; 71 import sun.reflect.CallerSensitive; 72 73 /** 74 * Generates bytecode for a Java adapter class. Used by the {@link JavaAdapterFactory}. 75 * </p><p> 76 * For every protected or public constructor in the extended class, the adapter class will have either one or two 77 * public constructors (visibility of protected constructors in the extended class is promoted to public). 78 * <li> 79 * <li>For adapter classes with instance-level overrides, a constructor taking a trailing ScriptObject argument preceded 80 * by original constructor arguments is always created on the adapter class. When such a constructor is invoked, the 81 * passed ScriptObject's member functions are used to implement and/or override methods on the original class, 82 * dispatched by name. A single JavaScript function will act as the implementation for all overloaded methods of the 83 * same name. When methods on an adapter instance are invoked, the functions are invoked having the ScriptObject passed 84 * in the instance constructor as their "this". Subsequent changes to the ScriptObject (reassignment or removal of its 85 * functions) are not reflected in the adapter instance; the method implementations are bound to functions at 86 * constructor invocation time. 87 * {@code java.lang.Object} methods {@code equals}, {@code hashCode}, and {@code toString} can also be overridden. The 88 * only restriction is that since every JavaScript object already has a {@code toString} function through the 89 * {@code Object.prototype}, the {@code toString} in the adapter is only overridden if the passed ScriptObject has a 90 * {@code toString} function as its own property, and not inherited from a prototype. All other adapter methods can be 91 * implemented or overridden through a prototype-inherited function of the ScriptObject passed to the constructor too. 92 * </li> 93 * <li> 94 * If the original types collectively have only one abstract method, or have several of them, but all share the 95 * same name, an additional constructor for instance-level override adapter is provided for every original constructor; 96 * this one takes a ScriptFunction as its last argument preceded by original constructor arguments. This constructor 97 * will use the passed function as the implementation for all abstract methods. For consistency, any concrete methods 98 * sharing the single abstract method name will also be overridden by the function. When methods on the adapter instance 99 * are invoked, the ScriptFunction is invoked with UNDEFINED or Global as its "this" depending whether the function is 100 * strict or not. 101 * </li> 102 * <li> 103 * If the adapter being generated can have class-level overrides, constructors taking same arguments as the superclass 104 * constructors are created. These constructors simply delegate to the superclass constructor. They are simply used to 105 * create instances of the adapter class, with no instance-level overrides, as they don't have them. 106 * </li> 107 * </ul> 108 * </p><p> 109 * For adapter methods that return values, all the JavaScript-to-Java conversions supported by Nashorn will be in effect 110 * to coerce the JavaScript function return value to the expected Java return type. 111 * </p><p> 112 * Since we are adding a trailing argument to the generated constructors in the adapter class, they will never be 113 * declared as variable arity, even if the original constructor in the superclass was declared as variable arity. The 114 * reason we are passing the additional argument at the end of the argument list instead at the front is that the 115 * source-level script expression <code>new X(a, b) { ... }</code> (which is a proprietary syntax extension Nashorn uses 116 * to resemble Java anonymous classes) is actually equivalent to <code>new X(a, b, { ... })</code>. 117 * </p><p> 118 * It is possible to create two different adapter classes: those that can have class-level overrides, and those that can 119 * have instance-level overrides. When {@link JavaAdapterFactory#getAdapterClassFor(Class[], ScriptObject)} is invoked 120 * with non-null {@code classOverrides} parameter, an adapter class is created that can have class-level overrides, and 121 * the passed script object will be used as the implementations for its methods, just as in the above case of the 122 * constructor taking a script object. Note that in the case of class-level overrides, a new adapter class is created on 123 * every invocation, and the implementation object is bound to the class, not to any instance. All created instances 124 * will share these functions. If it is required to have both class-level overrides and instance-level overrides, the 125 * class-level override adapter class should be subclassed with an instance-override adapter. Since adapters delegate to 126 * super class when an overriding method handle is not specified, this will behave as expected. It is not possible to 127 * have both class-level and instance-level overrides in the same class for security reasons: adapter classes are 128 * defined with a protection domain of their creator code, and an adapter class that has both class and instance level 129 * overrides would need to have two potentially different protection domains: one for class-based behavior and one for 130 * instance-based behavior; since Java classes can only belong to a single protection domain, this could not be 131 * implemented securely. 132 */ 133 final class JavaAdapterBytecodeGenerator { 134 static final Type CONTEXT_TYPE = Type.getType(Context.class); 135 static final Type OBJECT_TYPE = Type.getType(Object.class); 136 static final Type SCRIPT_OBJECT_TYPE = Type.getType(ScriptObject.class); 137 138 static final String CONTEXT_TYPE_NAME = CONTEXT_TYPE.getInternalName(); 139 static final String OBJECT_TYPE_NAME = OBJECT_TYPE.getInternalName(); 140 141 static final String INIT = "<init>"; 142 143 static final String GLOBAL_FIELD_NAME = "global"; 144 145 static final String SCRIPT_OBJECT_TYPE_DESCRIPTOR = SCRIPT_OBJECT_TYPE.getDescriptor(); 146 147 static final String SET_GLOBAL_METHOD_DESCRIPTOR = Type.getMethodDescriptor(Type.VOID_TYPE, SCRIPT_OBJECT_TYPE); 148 static final String VOID_NOARG_METHOD_DESCRIPTOR = Type.getMethodDescriptor(Type.VOID_TYPE); 149 150 private static final Type SCRIPT_FUNCTION_TYPE = Type.getType(ScriptFunction.class); 151 private static final Type STRING_TYPE = Type.getType(String.class); 152 private static final Type METHOD_TYPE_TYPE = Type.getType(MethodType.class); 153 private static final Type METHOD_HANDLE_TYPE = Type.getType(MethodHandle.class); 154 private static final String GET_HANDLE_OBJECT_DESCRIPTOR = Type.getMethodDescriptor(METHOD_HANDLE_TYPE, 155 OBJECT_TYPE, STRING_TYPE, METHOD_TYPE_TYPE); 156 private static final String GET_HANDLE_FUNCTION_DESCRIPTOR = Type.getMethodDescriptor(METHOD_HANDLE_TYPE, 157 SCRIPT_FUNCTION_TYPE, METHOD_TYPE_TYPE); 158 private static final String GET_CLASS_INITIALIZER_DESCRIPTOR = Type.getMethodDescriptor(SCRIPT_OBJECT_TYPE); 159 private static final Type RUNTIME_EXCEPTION_TYPE = Type.getType(RuntimeException.class); 160 private static final Type THROWABLE_TYPE = Type.getType(Throwable.class); 161 private static final Type UNSUPPORTED_OPERATION_TYPE = Type.getType(UnsupportedOperationException.class); 162 163 private static final String SERVICES_CLASS_TYPE_NAME = Type.getInternalName(JavaAdapterServices.class); 164 private static final String RUNTIME_EXCEPTION_TYPE_NAME = RUNTIME_EXCEPTION_TYPE.getInternalName(); 165 private static final String ERROR_TYPE_NAME = Type.getInternalName(Error.class); 166 private static final String THROWABLE_TYPE_NAME = THROWABLE_TYPE.getInternalName(); 167 private static final String UNSUPPORTED_OPERATION_TYPE_NAME = UNSUPPORTED_OPERATION_TYPE.getInternalName(); 168 169 private static final String METHOD_HANDLE_TYPE_DESCRIPTOR = METHOD_HANDLE_TYPE.getDescriptor(); 170 private static final String GET_GLOBAL_METHOD_DESCRIPTOR = Type.getMethodDescriptor(SCRIPT_OBJECT_TYPE); 171 private static final String GET_CLASS_METHOD_DESCRIPTOR = Type.getMethodDescriptor(Type.getType(Class.class)); 172 173 // Package used when the adapter can't be defined in the adaptee's package (either because it's sealed, or because 174 // it's a java.* package. 175 private static final String ADAPTER_PACKAGE_PREFIX = "jdk/nashorn/javaadapters/"; 176 // Class name suffix used to append to the adaptee class name, when it can be defined in the adaptee's package. 177 private static final String ADAPTER_CLASS_NAME_SUFFIX = "$$NashornJavaAdapter"; 178 private static final String JAVA_PACKAGE_PREFIX = "java/"; 179 private static final int MAX_GENERATED_TYPE_NAME_LENGTH = 255; 180 181 private static final String CLASS_INIT = "<clinit>"; 182 183 // Method name prefix for invoking super-methods 184 static final String SUPER_PREFIX = "super$"; 185 186 /** 187 * Collection of methods we never override: Object.clone(), Object.finalize(). 188 */ 189 private static final Collection<MethodInfo> EXCLUDED = getExcludedMethods(); 190 191 // This is the superclass for our generated adapter. 192 private final Class<?> superClass; 193 // Class loader used as the parent for the class loader we'll create to load the generated class. It will be a class 194 // loader that has the visibility of all original types (class to extend and interfaces to implement) and of the 195 // Nashorn classes. 196 private final ClassLoader commonLoader; 197 // Is this a generator for the version of the class that can have overrides on the class level? 198 private final boolean classOverride; 199 // Binary name of the superClass 200 private final String superClassName; 201 // Binary name of the generated class. 202 private final String generatedClassName; 203 private final Set<String> usedFieldNames = new HashSet<>(); 204 private final Set<String> abstractMethodNames = new HashSet<>(); 205 private final String samName; 206 private final Set<MethodInfo> finalMethods = new HashSet<>(EXCLUDED); 207 private final Set<MethodInfo> methodInfos = new HashSet<>(); 208 private boolean autoConvertibleFromFunction = false; 209 private boolean hasExplicitFinalizer = false; 210 211 private final ClassWriter cw; 212 213 /** 214 * Creates a generator for the bytecode for the adapter for the specified superclass and interfaces. 215 * @param superClass the superclass the adapter will extend. 216 * @param interfaces the interfaces the adapter will implement. 217 * @param commonLoader the class loader that can see all of superClass, interfaces, and Nashorn classes. 218 * @param classOverride true to generate the bytecode for the adapter that has class-level overrides, false to 219 * generate the bytecode for the adapter that has instance-level overrides. 220 * @throws AdaptationException if the adapter can not be generated for some reason. 221 */ 222 JavaAdapterBytecodeGenerator(final Class<?> superClass, final List<Class<?>> interfaces, 223 final ClassLoader commonLoader, final boolean classOverride) throws AdaptationException { 224 assert superClass != null && !superClass.isInterface(); 225 assert interfaces != null; 226 227 this.superClass = superClass; 228 this.classOverride = classOverride; 229 this.commonLoader = commonLoader; 230 cw = new ClassWriter(ClassWriter.COMPUTE_FRAMES | ClassWriter.COMPUTE_MAXS) { 231 @Override 232 protected String getCommonSuperClass(final String type1, final String type2) { 233 // We need to override ClassWriter.getCommonSuperClass to use this factory's commonLoader as a class 234 // loader to find the common superclass of two types when needed. 235 return JavaAdapterBytecodeGenerator.this.getCommonSuperClass(type1, type2); 236 } 237 }; 238 superClassName = Type.getInternalName(superClass); 239 generatedClassName = getGeneratedClassName(superClass, interfaces); 240 241 cw.visit(Opcodes.V1_7, ACC_PUBLIC | ACC_SUPER, generatedClassName, null, superClassName, getInternalTypeNames(interfaces)); 242 generateGlobalFields(); 243 244 gatherMethods(superClass); 245 gatherMethods(interfaces); 246 samName = abstractMethodNames.size() == 1 ? abstractMethodNames.iterator().next() : null; 247 generateHandleFields(); 248 if(classOverride) { 249 generateClassInit(); 250 } 251 generateConstructors(); 252 generateMethods(); 253 generateSuperMethods(); 254 if (hasExplicitFinalizer) { 255 generateFinalizerMethods(); 256 } 257 // } 258 cw.visitEnd(); 259 } 260 261 private void generateGlobalFields() { 262 cw.visitField(ACC_PRIVATE | ACC_FINAL | (classOverride ? ACC_STATIC : 0), GLOBAL_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR, null, null).visitEnd(); 263 usedFieldNames.add(GLOBAL_FIELD_NAME); 264 } 265 266 JavaAdapterClassLoader createAdapterClassLoader() { 267 return new JavaAdapterClassLoader(generatedClassName, cw.toByteArray()); 268 } 269 270 boolean isAutoConvertibleFromFunction() { 271 return autoConvertibleFromFunction; 272 } 273 274 private static String getGeneratedClassName(final Class<?> superType, final List<Class<?>> interfaces) { 275 // The class we use to primarily name our adapter is either the superclass, or if it is Object (meaning we're 276 // just implementing interfaces or extending Object), then the first implemented interface or Object. 277 final Class<?> namingType = superType == Object.class ? (interfaces.isEmpty()? Object.class : interfaces.get(0)) : superType; 278 final Package pkg = namingType.getPackage(); 279 final String namingTypeName = Type.getInternalName(namingType); 280 final StringBuilder buf = new StringBuilder(); 281 if (namingTypeName.startsWith(JAVA_PACKAGE_PREFIX) || pkg == null || pkg.isSealed()) { 282 // Can't define new classes in java.* packages 283 buf.append(ADAPTER_PACKAGE_PREFIX).append(namingTypeName); 284 } else { 285 buf.append(namingTypeName).append(ADAPTER_CLASS_NAME_SUFFIX); 286 } 287 final Iterator<Class<?>> it = interfaces.iterator(); 288 if(superType == Object.class && it.hasNext()) { 289 it.next(); // Skip first interface, it was used to primarily name the adapter 290 } 291 // Append interface names to the adapter name 292 while(it.hasNext()) { 293 buf.append("$$").append(it.next().getSimpleName()); 294 } 295 return buf.toString().substring(0, Math.min(MAX_GENERATED_TYPE_NAME_LENGTH, buf.length())); 296 } 297 298 /** 299 * Given a list of class objects, return an array with their binary names. Used to generate the array of interface 300 * names to implement. 301 * @param classes the classes 302 * @return an array of names 303 */ 304 private static String[] getInternalTypeNames(final List<Class<?>> classes) { 305 final int interfaceCount = classes.size(); 306 final String[] interfaceNames = new String[interfaceCount]; 307 for(int i = 0; i < interfaceCount; ++i) { 308 interfaceNames[i] = Type.getInternalName(classes.get(i)); 309 } 310 return interfaceNames; 311 } 312 313 private void generateHandleFields() { 314 final int flags = ACC_PRIVATE | ACC_FINAL | (classOverride ? ACC_STATIC : 0); 315 for (final MethodInfo mi: methodInfos) { 316 cw.visitField(flags, mi.methodHandleFieldName, METHOD_HANDLE_TYPE_DESCRIPTOR, null, null).visitEnd(); 317 } 318 } 319 320 private void generateClassInit() { 321 final InstructionAdapter mv = new InstructionAdapter(cw.visitMethod(ACC_STATIC, CLASS_INIT, 322 Type.getMethodDescriptor(Type.VOID_TYPE), null, null)); 323 324 mv.invokestatic(SERVICES_CLASS_TYPE_NAME, "getClassOverrides", GET_CLASS_INITIALIZER_DESCRIPTOR, false); 325 final Label initGlobal; 326 if(samName != null) { 327 // If the class is a SAM, allow having a ScriptFunction passed as class overrides 328 final Label notAFunction = new Label(); 329 mv.dup(); 330 mv.instanceOf(SCRIPT_FUNCTION_TYPE); 331 mv.ifeq(notAFunction); 332 mv.checkcast(SCRIPT_FUNCTION_TYPE); 333 334 // Assign MethodHandle fields through invoking getHandle() for a ScriptFunction, only assigning the SAM 335 // method(s). 336 for (final MethodInfo mi : methodInfos) { 337 if(mi.getName().equals(samName)) { 338 mv.dup(); 339 mv.aconst(Type.getMethodType(mi.type.toMethodDescriptorString())); 340 mv.invokestatic(SERVICES_CLASS_TYPE_NAME, "getHandle", GET_HANDLE_FUNCTION_DESCRIPTOR, false); 341 } else { 342 mv.visitInsn(ACONST_NULL); 343 } 344 mv.putstatic(generatedClassName, mi.methodHandleFieldName, METHOD_HANDLE_TYPE_DESCRIPTOR); 345 } 346 initGlobal = new Label(); 347 mv.goTo(initGlobal); 348 mv.visitLabel(notAFunction); 349 } else { 350 initGlobal = null; 351 } 352 // Assign MethodHandle fields through invoking getHandle() for a ScriptObject 353 for (final MethodInfo mi : methodInfos) { 354 mv.dup(); 355 mv.aconst(mi.getName()); 356 mv.aconst(Type.getMethodType(mi.type.toMethodDescriptorString())); 357 mv.invokestatic(SERVICES_CLASS_TYPE_NAME, "getHandle", GET_HANDLE_OBJECT_DESCRIPTOR, false); 358 mv.putstatic(generatedClassName, mi.methodHandleFieldName, METHOD_HANDLE_TYPE_DESCRIPTOR); 359 } 360 361 if(initGlobal != null) { 362 mv.visitLabel(initGlobal); 363 } 364 // Assign "global = Context.getGlobal()" 365 invokeGetGlobalWithNullCheck(mv); 366 mv.putstatic(generatedClassName, GLOBAL_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR); 367 368 endInitMethod(mv); 369 } 370 371 private static void invokeGetGlobalWithNullCheck(final InstructionAdapter mv) { 372 invokeGetGlobal(mv); 373 mv.dup(); 374 mv.invokevirtual(OBJECT_TYPE_NAME, "getClass", GET_CLASS_METHOD_DESCRIPTOR, false); // check against null Context 375 mv.pop(); 376 } 377 378 private void generateConstructors() throws AdaptationException { 379 boolean gotCtor = false; 380 for (final Constructor<?> ctor: superClass.getDeclaredConstructors()) { 381 final int modifier = ctor.getModifiers(); 382 if((modifier & (Modifier.PUBLIC | Modifier.PROTECTED)) != 0 && !isCallerSensitive(ctor)) { 383 generateConstructors(ctor); 384 gotCtor = true; 385 } 386 } 387 if(!gotCtor) { 388 throw new AdaptationException(ERROR_NO_ACCESSIBLE_CONSTRUCTOR, superClass.getCanonicalName()); 389 } 390 } 391 392 private void generateConstructors(final Constructor<?> ctor) { 393 if(classOverride) { 394 // Generate a constructor that just delegates to ctor. This is used with class-level overrides, when we want 395 // to create instances without further per-instance overrides. 396 generateDelegatingConstructor(ctor); 397 } else { 398 // Generate a constructor that delegates to ctor, but takes an additional ScriptObject parameter at the 399 // beginning of its parameter list. 400 generateOverridingConstructor(ctor, false); 401 402 if (samName != null) { 403 if (!autoConvertibleFromFunction && ctor.getParameterTypes().length == 0) { 404 // If the original type only has a single abstract method name, as well as a default ctor, then it can 405 // be automatically converted from JS function. 406 autoConvertibleFromFunction = true; 407 } 408 // If all our abstract methods have a single name, generate an additional constructor, one that takes a 409 // ScriptFunction as its first parameter and assigns it as the implementation for all abstract methods. 410 generateOverridingConstructor(ctor, true); 411 } 412 } 413 } 414 415 private void generateDelegatingConstructor(final Constructor<?> ctor) { 416 final Type originalCtorType = Type.getType(ctor); 417 final Type[] argTypes = originalCtorType.getArgumentTypes(); 418 419 // All constructors must be public, even if in the superclass they were protected. 420 final InstructionAdapter mv = new InstructionAdapter(cw.visitMethod(ACC_PUBLIC, INIT, 421 Type.getMethodDescriptor(originalCtorType.getReturnType(), argTypes), null, null)); 422 423 mv.visitCode(); 424 // Invoke super constructor with the same arguments. 425 mv.visitVarInsn(ALOAD, 0); 426 int offset = 1; // First arg is at position 1, after this. 427 for (Type argType: argTypes) { 428 mv.load(offset, argType); 429 offset += argType.getSize(); 430 } 431 mv.invokespecial(superClassName, INIT, originalCtorType.getDescriptor(), false); 432 433 endInitMethod(mv); 434 } 435 436 /** 437 * Generates a constructor for the instance adapter class. This constructor will take the same arguments as the supertype 438 * constructor passed as the argument here, and delegate to it. However, it will take an additional argument of 439 * either ScriptObject or ScriptFunction type (based on the value of the "fromFunction" parameter), and initialize 440 * all the method handle fields of the adapter instance with functions from the script object (or the script 441 * function itself, if that's what's passed). There is one method handle field in the adapter class for every method 442 * that can be implemented or overridden; the name of every field is same as the name of the method, with a number 443 * suffix that makes it unique in case of overloaded methods. The generated constructor will invoke 444 * {@link #getHandle(ScriptFunction, MethodType, boolean)} or {@link #getHandle(Object, String, MethodType, 445 * boolean)} to obtain the method handles; these methods make sure to add the necessary conversions and arity 446 * adjustments so that the resulting method handles can be invoked from generated methods using {@code invokeExact}. 447 * The constructor that takes a script function will only initialize the methods with the same name as the single 448 * abstract method. The constructor will also store the Nashorn global that was current at the constructor 449 * invocation time in a field named "global". The generated constructor will be public, regardless of whether the 450 * supertype constructor was public or protected. The generated constructor will not be variable arity, even if the 451 * supertype constructor was. 452 * @param ctor the supertype constructor that is serving as the base for the generated constructor. 453 * @param fromFunction true if we're generating a constructor that initializes SAM types from a single 454 * ScriptFunction passed to it, false if we're generating a constructor that initializes an arbitrary type from a 455 * ScriptObject passed to it. 456 */ 457 private void generateOverridingConstructor(final Constructor<?> ctor, final boolean fromFunction) { 458 final Type originalCtorType = Type.getType(ctor); 459 final Type[] originalArgTypes = originalCtorType.getArgumentTypes(); 460 final int argLen = originalArgTypes.length; 461 final Type[] newArgTypes = new Type[argLen + 1]; 462 463 // Insert ScriptFunction|Object as the last argument to the constructor 464 final Type extraArgumentType = fromFunction ? SCRIPT_FUNCTION_TYPE : OBJECT_TYPE; 465 newArgTypes[argLen] = extraArgumentType; 466 System.arraycopy(originalArgTypes, 0, newArgTypes, 0, argLen); 467 468 // All constructors must be public, even if in the superclass they were protected. 469 // Existing super constructor <init>(this, args...) triggers generating <init>(this, scriptObj, args...). 470 final InstructionAdapter mv = new InstructionAdapter(cw.visitMethod(ACC_PUBLIC, INIT, 471 Type.getMethodDescriptor(originalCtorType.getReturnType(), newArgTypes), null, null)); 472 473 mv.visitCode(); 474 // First, invoke super constructor with original arguments. If the form of the constructor we're generating is 475 // <init>(this, args..., scriptFn), then we're invoking super.<init>(this, args...). 476 mv.visitVarInsn(ALOAD, 0); 477 final Class<?>[] argTypes = ctor.getParameterTypes(); 478 int offset = 1; // First arg is at position 1, after this. 479 for (int i = 0; i < argLen; ++i) { 480 final Type argType = Type.getType(argTypes[i]); 481 mv.load(offset, argType); 482 offset += argType.getSize(); 483 } 484 mv.invokespecial(superClassName, INIT, originalCtorType.getDescriptor(), false); 485 486 // Get a descriptor to the appropriate "JavaAdapterFactory.getHandle" method. 487 final String getHandleDescriptor = fromFunction ? GET_HANDLE_FUNCTION_DESCRIPTOR : GET_HANDLE_OBJECT_DESCRIPTOR; 488 489 // Assign MethodHandle fields through invoking getHandle() 490 for (final MethodInfo mi : methodInfos) { 491 mv.visitVarInsn(ALOAD, 0); 492 if (fromFunction && !mi.getName().equals(samName)) { 493 // Constructors initializing from a ScriptFunction only initialize methods with the SAM name. 494 // NOTE: if there's a concrete overloaded method sharing the SAM name, it'll be overriden too. This 495 // is a deliberate design choice. All other method handles are initialized to null. 496 mv.visitInsn(ACONST_NULL); 497 } else { 498 mv.visitVarInsn(ALOAD, offset); 499 if(!fromFunction) { 500 mv.aconst(mi.getName()); 501 } 502 mv.aconst(Type.getMethodType(mi.type.toMethodDescriptorString())); 503 mv.invokestatic(SERVICES_CLASS_TYPE_NAME, "getHandle", getHandleDescriptor, false); 504 } 505 mv.putfield(generatedClassName, mi.methodHandleFieldName, METHOD_HANDLE_TYPE_DESCRIPTOR); 506 } 507 508 // Assign "this.global = Context.getGlobal()" 509 mv.visitVarInsn(ALOAD, 0); 510 invokeGetGlobalWithNullCheck(mv); 511 mv.putfield(generatedClassName, GLOBAL_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR); 512 513 endInitMethod(mv); 514 } 515 516 private static void endInitMethod(final InstructionAdapter mv) { 517 mv.visitInsn(RETURN); 518 endMethod(mv); 519 } 520 521 private static void endMethod(final InstructionAdapter mv) { 522 mv.visitMaxs(0, 0); 523 mv.visitEnd(); 524 } 525 526 private static void invokeGetGlobal(final InstructionAdapter mv) { 527 mv.invokestatic(CONTEXT_TYPE_NAME, "getGlobal", GET_GLOBAL_METHOD_DESCRIPTOR, false); 528 } 529 530 private static void invokeSetGlobal(final InstructionAdapter mv) { 531 mv.invokestatic(CONTEXT_TYPE_NAME, "setGlobal", SET_GLOBAL_METHOD_DESCRIPTOR, false); 532 } 533 534 /** 535 * Encapsulation of the information used to generate methods in the adapter classes. Basically, a wrapper around the 536 * reflective Method object, a cached MethodType, and the name of the field in the adapter class that will hold the 537 * method handle serving as the implementation of this method in adapter instances. 538 * 539 */ 540 private static class MethodInfo { 541 private final Method method; 542 private final MethodType type; 543 private String methodHandleFieldName; 544 545 private MethodInfo(final Class<?> clazz, final String name, final Class<?>... argTypes) throws NoSuchMethodException { 546 this(clazz.getDeclaredMethod(name, argTypes)); 547 } 548 549 private MethodInfo(final Method method) { 550 this.method = method; 551 this.type = MH.type(method.getReturnType(), method.getParameterTypes()); 552 } 553 554 @Override 555 public boolean equals(final Object obj) { 556 return obj instanceof MethodInfo && equals((MethodInfo)obj); 557 } 558 559 private boolean equals(final MethodInfo other) { 560 // Only method name and type are used for comparison; method handle field name is not. 561 return getName().equals(other.getName()) && type.equals(other.type); 562 } 563 564 String getName() { 565 return method.getName(); 566 } 567 568 @Override 569 public int hashCode() { 570 return getName().hashCode() ^ type.hashCode(); 571 } 572 573 void setIsCanonical(final JavaAdapterBytecodeGenerator self) { 574 methodHandleFieldName = self.nextName(getName()); 575 } 576 } 577 578 private String nextName(final String name) { 579 int i = 0; 580 String nextName = name; 581 while (!usedFieldNames.add(nextName)) { 582 final String ordinal = String.valueOf(i++); 583 final int maxNameLen = 255 - ordinal.length(); 584 nextName = (name.length() <= maxNameLen ? name : name.substring(0, maxNameLen)).concat(ordinal); 585 } 586 return nextName; 587 } 588 589 private void generateMethods() { 590 for(final MethodInfo mi: methodInfos) { 591 generateMethod(mi); 592 } 593 } 594 595 /** 596 * Generates a method in the adapter class that adapts a method from the original class. The generated methods will 597 * inspect the method handle field assigned to them. If it is null (the JS object doesn't provide an implementation 598 * for the method) then it will either invoke its version in the supertype, or if it is abstract, throw an 599 * {@link UnsupportedOperationException}. Otherwise, if the method handle field's value is not null, the handle is 600 * invoked using invokeExact (signature polymorphic invocation as per JLS 15.12.3). Before the invocation, the 601 * current Nashorn {@link Context} is checked, and if it is different than the global used to create the adapter 602 * instance, the creating global is set to be the current global. In this case, the previously current global is 603 * restored after the invocation. If invokeExact results in a Throwable that is not one of the method's declared 604 * exceptions, and is not an unchecked throwable, then it is wrapped into a {@link RuntimeException} and the runtime 605 * exception is thrown. The method handle retrieved from the field is guaranteed to exactly match the signature of 606 * the method; this is guaranteed by the way constructors of the adapter class obtain them using 607 * {@link #getHandle(Object, String, MethodType, boolean)}. 608 * @param mi the method info describing the method to be generated. 609 */ 610 private void generateMethod(final MethodInfo mi) { 611 final Method method = mi.method; 612 final Class<?>[] exceptions = method.getExceptionTypes(); 613 final String[] exceptionNames = getExceptionNames(exceptions); 614 final MethodType type = mi.type; 615 final String methodDesc = type.toMethodDescriptorString(); 616 final String name = mi.getName(); 617 618 final Type asmType = Type.getMethodType(methodDesc); 619 final Type[] asmArgTypes = asmType.getArgumentTypes(); 620 621 final InstructionAdapter mv = new InstructionAdapter(cw.visitMethod(getAccessModifiers(method), name, 622 methodDesc, null, exceptionNames)); 623 mv.visitCode(); 624 625 final Label handleDefined = new Label(); 626 627 final Type asmReturnType = Type.getType(type.returnType()); 628 629 // See if we have overriding method handle defined 630 if(classOverride) { 631 mv.getstatic(generatedClassName, mi.methodHandleFieldName, METHOD_HANDLE_TYPE_DESCRIPTOR); 632 } else { 633 mv.visitVarInsn(ALOAD, 0); 634 mv.getfield(generatedClassName, mi.methodHandleFieldName, METHOD_HANDLE_TYPE_DESCRIPTOR); 635 } 636 // stack: [handle] 637 jumpIfNonNullKeepOperand(mv, handleDefined); 638 639 // No handle is available, fall back to default behavior 640 if(Modifier.isAbstract(method.getModifiers())) { 641 // If the super method is abstract, throw an exception 642 mv.anew(UNSUPPORTED_OPERATION_TYPE); 643 mv.dup(); 644 mv.invokespecial(UNSUPPORTED_OPERATION_TYPE_NAME, INIT, VOID_NOARG_METHOD_DESCRIPTOR, false); 645 mv.athrow(); 646 } else { 647 // If the super method is not abstract, delegate to it. 648 emitSuperCall(mv, method.getDeclaringClass(), name, methodDesc); 649 } 650 651 mv.visitLabel(handleDefined); 652 // Load the creatingGlobal object 653 if(classOverride) { 654 // If class handle is defined, load the static defining global 655 mv.getstatic(generatedClassName, GLOBAL_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR); 656 } else { 657 mv.visitVarInsn(ALOAD, 0); 658 mv.getfield(generatedClassName, GLOBAL_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR); 659 } 660 // stack: [creatingGlobal, handle] 661 final Label setupGlobal = new Label(); 662 mv.visitLabel(setupGlobal); 663 664 // Determine the first index for a local variable 665 int nextLocalVar = 1; // "this" is at 0 666 for(final Type t: asmArgTypes) { 667 nextLocalVar += t.getSize(); 668 } 669 // Set our local variable indices 670 final int currentGlobalVar = nextLocalVar++; 671 final int globalsDifferVar = nextLocalVar++; 672 673 mv.dup(); 674 // stack: [creatingGlobal, creatingGlobal, handle] 675 676 // Emit code for switching to the creating global 677 // ScriptObject currentGlobal = Context.getGlobal(); 678 invokeGetGlobal(mv); 679 mv.dup(); 680 681 mv.visitVarInsn(ASTORE, currentGlobalVar); 682 // stack: [currentGlobal, creatingGlobal, creatingGlobal, handle] 683 // if(definingGlobal == currentGlobal) { 684 final Label globalsDiffer = new Label(); 685 mv.ifacmpne(globalsDiffer); 686 // stack: [creatingGlobal, handle] 687 // globalsDiffer = false 688 mv.pop(); 689 // stack: [handle] 690 mv.iconst(0); // false 691 // stack: [false, handle] 692 final Label invokeHandle = new Label(); 693 mv.goTo(invokeHandle); 694 mv.visitLabel(globalsDiffer); 695 // } else { 696 // Context.setGlobal(definingGlobal); 697 // stack: [creatingGlobal, handle] 698 invokeSetGlobal(mv); 699 // stack: [handle] 700 // globalsDiffer = true 701 mv.iconst(1); 702 // stack: [true, handle] 703 704 mv.visitLabel(invokeHandle); 705 mv.visitVarInsn(ISTORE, globalsDifferVar); 706 // stack: [handle] 707 708 // Load all parameters back on stack for dynamic invocation. 709 int varOffset = 1; 710 for (final Type t : asmArgTypes) { 711 mv.load(varOffset, t); 712 varOffset += t.getSize(); 713 } 714 715 // Invoke the target method handle 716 final Label tryBlockStart = new Label(); 717 mv.visitLabel(tryBlockStart); 718 mv.invokevirtual(METHOD_HANDLE_TYPE.getInternalName(), "invokeExact", type.toMethodDescriptorString(), false); 719 final Label tryBlockEnd = new Label(); 720 mv.visitLabel(tryBlockEnd); 721 emitFinally(mv, currentGlobalVar, globalsDifferVar); 722 mv.areturn(asmReturnType); 723 724 // If Throwable is not declared, we need an adapter from Throwable to RuntimeException 725 final boolean throwableDeclared = isThrowableDeclared(exceptions); 726 final Label throwableHandler; 727 if (!throwableDeclared) { 728 // Add "throw new RuntimeException(Throwable)" handler for Throwable 729 throwableHandler = new Label(); 730 mv.visitLabel(throwableHandler); 731 mv.anew(RUNTIME_EXCEPTION_TYPE); 732 mv.dupX1(); 733 mv.swap(); 734 mv.invokespecial(RUNTIME_EXCEPTION_TYPE_NAME, INIT, Type.getMethodDescriptor(Type.VOID_TYPE, THROWABLE_TYPE), false); 735 // Fall through to rethrow handler 736 } else { 737 throwableHandler = null; 738 } 739 final Label rethrowHandler = new Label(); 740 mv.visitLabel(rethrowHandler); 741 // Rethrow handler for RuntimeException, Error, and all declared exception types 742 emitFinally(mv, currentGlobalVar, globalsDifferVar); 743 mv.athrow(); 744 final Label methodEnd = new Label(); 745 mv.visitLabel(methodEnd); 746 747 mv.visitLocalVariable("currentGlobal", SCRIPT_OBJECT_TYPE_DESCRIPTOR, null, setupGlobal, methodEnd, currentGlobalVar); 748 mv.visitLocalVariable("globalsDiffer", Type.INT_TYPE.getDescriptor(), null, setupGlobal, methodEnd, globalsDifferVar); 749 750 if(throwableDeclared) { 751 mv.visitTryCatchBlock(tryBlockStart, tryBlockEnd, rethrowHandler, THROWABLE_TYPE_NAME); 752 assert throwableHandler == null; 753 } else { 754 mv.visitTryCatchBlock(tryBlockStart, tryBlockEnd, rethrowHandler, RUNTIME_EXCEPTION_TYPE_NAME); 755 mv.visitTryCatchBlock(tryBlockStart, tryBlockEnd, rethrowHandler, ERROR_TYPE_NAME); 756 for(final String excName: exceptionNames) { 757 mv.visitTryCatchBlock(tryBlockStart, tryBlockEnd, rethrowHandler, excName); 758 } 759 mv.visitTryCatchBlock(tryBlockStart, tryBlockEnd, throwableHandler, THROWABLE_TYPE_NAME); 760 } 761 endMethod(mv); 762 } 763 764 /** 765 * Emits code for jumping to a label if the top stack operand is not null. The operand is kept on the stack if it 766 * is not null (so is available to code at the jump address) and is popped if it is null. 767 * @param mv the instruction adapter being used to emit code 768 * @param label the label to jump to 769 */ 770 private static void jumpIfNonNullKeepOperand(final InstructionAdapter mv, final Label label) { 771 mv.visitInsn(DUP); 772 mv.visitJumpInsn(IFNONNULL, label); 773 mv.visitInsn(POP); 774 } 775 776 /** 777 * Emit code to restore the previous Nashorn Context when needed. 778 * @param mv the instruction adapter 779 * @param currentGlobalVar index of the local variable holding the reference to the current global at method 780 * entry. 781 * @param globalsDifferVar index of the boolean local variable that is true if the global needs to be restored. 782 */ 783 private static void emitFinally(final InstructionAdapter mv, final int currentGlobalVar, final int globalsDifferVar) { 784 // Emit code to restore the previous Nashorn global if needed 785 mv.visitVarInsn(ILOAD, globalsDifferVar); 786 final Label skip = new Label(); 787 mv.ifeq(skip); 788 mv.visitVarInsn(ALOAD, currentGlobalVar); 789 invokeSetGlobal(mv); 790 mv.visitLabel(skip); 791 } 792 793 private static boolean isThrowableDeclared(final Class<?>[] exceptions) { 794 for (final Class<?> exception : exceptions) { 795 if (exception == Throwable.class) { 796 return true; 797 } 798 } 799 return false; 800 } 801 802 private void generateSuperMethods() { 803 for(final MethodInfo mi: methodInfos) { 804 if(!Modifier.isAbstract(mi.method.getModifiers())) { 805 generateSuperMethod(mi); 806 } 807 } 808 } 809 810 private void generateSuperMethod(MethodInfo mi) { 811 final Method method = mi.method; 812 813 final String methodDesc = mi.type.toMethodDescriptorString(); 814 final String name = mi.getName(); 815 816 final InstructionAdapter mv = new InstructionAdapter(cw.visitMethod(getAccessModifiers(method), 817 SUPER_PREFIX + name, methodDesc, null, getExceptionNames(method.getExceptionTypes()))); 818 mv.visitCode(); 819 820 emitSuperCall(mv, method.getDeclaringClass(), name, methodDesc); 821 822 endMethod(mv); 823 } 824 825 private void emitSuperCall(final InstructionAdapter mv, final Class<?> owner, final String name, final String methodDesc) { 826 mv.visitVarInsn(ALOAD, 0); 827 int nextParam = 1; 828 final Type methodType = Type.getMethodType(methodDesc); 829 for(final Type t: methodType.getArgumentTypes()) { 830 mv.load(nextParam, t); 831 nextParam += t.getSize(); 832 } 833 834 // default method - non-abstract, interface method 835 if (Modifier.isInterface(owner.getModifiers())) { 836 mv.invokespecial(Type.getInternalName(owner), name, methodDesc, false); 837 } else { 838 mv.invokespecial(superClassName, name, methodDesc, false); 839 } 840 mv.areturn(methodType.getReturnType()); 841 } 842 843 private void generateFinalizerMethods() { 844 final String finalizerDelegateName = nextName("access$"); 845 generateFinalizerDelegate(finalizerDelegateName); 846 generateFinalizerOverride(finalizerDelegateName); 847 } 848 849 private void generateFinalizerDelegate(final String finalizerDelegateName) { 850 // Generate a delegate that will be invoked from the no-permission trampoline. Note it can be private, as we'll 851 // refer to it with a MethodHandle constant pool entry in the overridden finalize() method (see 852 // generateFinalizerOverride()). 853 final InstructionAdapter mv = new InstructionAdapter(cw.visitMethod(ACC_PRIVATE | ACC_STATIC, 854 finalizerDelegateName, Type.getMethodDescriptor(Type.VOID_TYPE, OBJECT_TYPE), null, null)); 855 856 // Simply invoke super.finalize() 857 mv.visitVarInsn(ALOAD, 0); 858 mv.checkcast(Type.getType(generatedClassName)); 859 mv.invokespecial(superClassName, "finalize", Type.getMethodDescriptor(Type.VOID_TYPE), false); 860 861 mv.visitInsn(RETURN); 862 endMethod(mv); 863 } 864 865 private void generateFinalizerOverride(final String finalizerDelegateName) { 866 final InstructionAdapter mv = new InstructionAdapter(cw.visitMethod(ACC_PUBLIC, "finalize", 867 VOID_NOARG_METHOD_DESCRIPTOR, null, null)); 868 // Overridden finalizer will take a MethodHandle to the finalizer delegating method, ... 869 mv.aconst(new Handle(Opcodes.H_INVOKESTATIC, generatedClassName, finalizerDelegateName, 870 Type.getMethodDescriptor(Type.VOID_TYPE, OBJECT_TYPE))); 871 mv.visitVarInsn(ALOAD, 0); 872 // ...and invoke it through JavaAdapterServices.invokeNoPermissions 873 mv.invokestatic(SERVICES_CLASS_TYPE_NAME, "invokeNoPermissions", 874 Type.getMethodDescriptor(METHOD_HANDLE_TYPE, OBJECT_TYPE), false); 875 mv.visitInsn(RETURN); 876 endMethod(mv); 877 } 878 879 private static String[] getExceptionNames(final Class<?>[] exceptions) { 880 final String[] exceptionNames = new String[exceptions.length]; 881 for (int i = 0; i < exceptions.length; ++i) { 882 exceptionNames[i] = Type.getInternalName(exceptions[i]); 883 } 884 return exceptionNames; 885 } 886 887 private static int getAccessModifiers(final Method method) { 888 return ACC_PUBLIC | (method.isVarArgs() ? ACC_VARARGS : 0); 889 } 890 891 /** 892 * Gathers methods that can be implemented or overridden from the specified type into this factory's 893 * {@link #methodInfos} set. It will add all non-final, non-static methods that are either public or protected from 894 * the type if the type itself is public. If the type is a class, the method will recursively invoke itself for its 895 * superclass and the interfaces it implements, and add further methods that were not directly declared on the 896 * class. 897 * @param type the type defining the methods. 898 */ 899 private void gatherMethods(final Class<?> type) throws AdaptationException { 900 if (Modifier.isPublic(type.getModifiers())) { 901 final Method[] typeMethods = type.isInterface() ? type.getMethods() : type.getDeclaredMethods(); 902 903 for (final Method typeMethod: typeMethods) { 904 final String name = typeMethod.getName(); 905 if(name.startsWith(SUPER_PREFIX)) { 906 continue; 907 } 908 final int m = typeMethod.getModifiers(); 909 if (Modifier.isStatic(m)) { 910 continue; 911 } 912 if (Modifier.isPublic(m) || Modifier.isProtected(m)) { 913 // Is it a "finalize()"? 914 if(name.equals("finalize") && typeMethod.getParameterCount() == 0) { 915 if(type != Object.class) { 916 hasExplicitFinalizer = true; 917 if(Modifier.isFinal(m)) { 918 // Must be able to override an explicit finalizer 919 throw new AdaptationException(Outcome.ERROR_FINAL_FINALIZER, type.getCanonicalName()); 920 } 921 } 922 continue; 923 } 924 925 final MethodInfo mi = new MethodInfo(typeMethod); 926 if (Modifier.isFinal(m) || isCallerSensitive(typeMethod)) { 927 finalMethods.add(mi); 928 } else if (!finalMethods.contains(mi) && methodInfos.add(mi)) { 929 if (Modifier.isAbstract(m)) { 930 abstractMethodNames.add(mi.getName()); 931 } 932 mi.setIsCanonical(this); 933 } 934 } 935 } 936 } 937 // If the type is a class, visit its superclasses and declared interfaces. If it's an interface, we're done. 938 // Needing to invoke the method recursively for a non-interface Class object is the consequence of needing to 939 // see all declared protected methods, and Class.getDeclaredMethods() doesn't provide those declared in a 940 // superclass. For interfaces, we used Class.getMethods(), as we're only interested in public ones there, and 941 // getMethods() does provide those declared in a superinterface. 942 if (!type.isInterface()) { 943 final Class<?> superType = type.getSuperclass(); 944 if (superType != null) { 945 gatherMethods(superType); 946 } 947 for (final Class<?> itf: type.getInterfaces()) { 948 gatherMethods(itf); 949 } 950 } 951 } 952 953 private void gatherMethods(final List<Class<?>> classes) throws AdaptationException { 954 for(final Class<?> c: classes) { 955 gatherMethods(c); 956 } 957 } 958 959 private static final AccessControlContext GET_DECLARED_MEMBERS_ACC_CTXT = ClassAndLoader.createPermAccCtxt("accessDeclaredMembers"); 960 961 /** 962 * Creates a collection of methods that are not final, but we still never allow them to be overridden in adapters, 963 * as explicitly declaring them automatically is a bad idea. Currently, this means {@code Object.finalize()} and 964 * {@code Object.clone()}. 965 * @return a collection of method infos representing those methods that we never override in adapter classes. 966 */ 967 private static Collection<MethodInfo> getExcludedMethods() { 968 return AccessController.doPrivileged(new PrivilegedAction<Collection<MethodInfo>>() { 969 @Override 970 public Collection<MethodInfo> run() { 971 try { 972 return Arrays.asList( 973 new MethodInfo(Object.class, "finalize"), 974 new MethodInfo(Object.class, "clone")); 975 } catch (final NoSuchMethodException e) { 976 throw new AssertionError(e); 977 } 978 } 979 }, GET_DECLARED_MEMBERS_ACC_CTXT); 980 } 981 982 private String getCommonSuperClass(final String type1, final String type2) { 983 try { 984 final Class<?> c1 = Class.forName(type1.replace('/', '.'), false, commonLoader); 985 final Class<?> c2 = Class.forName(type2.replace('/', '.'), false, commonLoader); 986 if (c1.isAssignableFrom(c2)) { 987 return type1; 988 } 989 if (c2.isAssignableFrom(c1)) { 990 return type2; 991 } 992 if (c1.isInterface() || c2.isInterface()) { 993 return OBJECT_TYPE_NAME; 994 } 995 return assignableSuperClass(c1, c2).getName().replace('.', '/'); 996 } catch(final ClassNotFoundException e) { 997 throw new RuntimeException(e); 998 } 999 } 1000 1001 private static Class<?> assignableSuperClass(final Class<?> c1, final Class<?> c2) { 1002 final Class<?> superClass = c1.getSuperclass(); 1003 return superClass.isAssignableFrom(c2) ? superClass : assignableSuperClass(superClass, c2); 1004 } 1005 1006 private static boolean isCallerSensitive(final AccessibleObject e) { 1007 return e.isAnnotationPresent(CallerSensitive.class); 1008 } 1009 }