JavaAdapterBytecodeGenerator.java revision 1643:133ea8746b37
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 26package jdk.nashorn.internal.runtime.linker; 27 28import static jdk.internal.org.objectweb.asm.Opcodes.ACC_FINAL; 29import static jdk.internal.org.objectweb.asm.Opcodes.ACC_PRIVATE; 30import static jdk.internal.org.objectweb.asm.Opcodes.ACC_PUBLIC; 31import static jdk.internal.org.objectweb.asm.Opcodes.ACC_STATIC; 32import static jdk.internal.org.objectweb.asm.Opcodes.ACC_SUPER; 33import static jdk.internal.org.objectweb.asm.Opcodes.ACC_VARARGS; 34import static jdk.internal.org.objectweb.asm.Opcodes.ALOAD; 35import static jdk.internal.org.objectweb.asm.Opcodes.ASTORE; 36import static jdk.internal.org.objectweb.asm.Opcodes.D2F; 37import static jdk.internal.org.objectweb.asm.Opcodes.H_INVOKESTATIC; 38import static jdk.internal.org.objectweb.asm.Opcodes.I2B; 39import static jdk.internal.org.objectweb.asm.Opcodes.I2S; 40import static jdk.internal.org.objectweb.asm.Opcodes.RETURN; 41import static jdk.nashorn.internal.codegen.CompilerConstants.interfaceCallNoLookup; 42import static jdk.nashorn.internal.codegen.CompilerConstants.staticCallNoLookup; 43import static jdk.nashorn.internal.lookup.Lookup.MH; 44import static jdk.nashorn.internal.runtime.linker.AdaptationResult.Outcome.ERROR_NO_ACCESSIBLE_CONSTRUCTOR; 45 46import java.lang.invoke.CallSite; 47import java.lang.invoke.MethodHandle; 48import java.lang.invoke.MethodHandles.Lookup; 49import java.lang.invoke.MethodType; 50import java.lang.reflect.AccessibleObject; 51import java.lang.reflect.Constructor; 52import java.lang.reflect.Method; 53import java.lang.reflect.Modifier; 54import java.lang.reflect.Module; 55import java.security.AccessControlContext; 56import java.security.AccessController; 57import java.security.PrivilegedAction; 58import java.util.Arrays; 59import java.util.Collection; 60import java.util.HashSet; 61import java.util.Iterator; 62import java.util.List; 63import java.util.Set; 64import jdk.internal.org.objectweb.asm.ClassWriter; 65import jdk.internal.org.objectweb.asm.Handle; 66import jdk.internal.org.objectweb.asm.Label; 67import jdk.internal.org.objectweb.asm.Opcodes; 68import jdk.internal.org.objectweb.asm.Type; 69import jdk.internal.org.objectweb.asm.commons.InstructionAdapter; 70import jdk.nashorn.api.scripting.ScriptUtils; 71import jdk.nashorn.internal.codegen.CompilerConstants.Call; 72import jdk.nashorn.internal.runtime.ScriptFunction; 73import jdk.nashorn.internal.runtime.ScriptObject; 74import jdk.nashorn.internal.runtime.linker.AdaptationResult.Outcome; 75import sun.reflect.CallerSensitive; 76 77/** 78 * Generates bytecode for a Java adapter class. Used by the {@link JavaAdapterFactory}. 79 * </p><p> 80 * For every protected or public constructor in the extended class, the adapter class will have either one or two 81 * public constructors (visibility of protected constructors in the extended class is promoted to public). 82 * <li> 83 * <li>For adapter classes with instance-level overrides, a constructor taking a trailing ScriptObject argument preceded 84 * by original constructor arguments is always created on the adapter class. When such a constructor is invoked, the 85 * passed ScriptObject's member functions are used to implement and/or override methods on the original class, 86 * dispatched by name. A single JavaScript function will act as the implementation for all overloaded methods of the 87 * same name. When methods on an adapter instance are invoked, the functions are invoked having the ScriptObject passed 88 * in the instance constructor as their "this". Subsequent changes to the ScriptObject (reassignment or removal of its 89 * functions) will be reflected in the adapter instance as it is live dispatching to its members on every method invocation. 90 * {@code java.lang.Object} methods {@code equals}, {@code hashCode}, and {@code toString} can also be overridden. The 91 * only restriction is that since every JavaScript object already has a {@code toString} function through the 92 * {@code Object.prototype}, the {@code toString} in the adapter is only overridden if the passed ScriptObject has a 93 * {@code toString} function as its own property, and not inherited from a prototype. All other adapter methods can be 94 * implemented or overridden through a prototype-inherited function of the ScriptObject passed to the constructor too. 95 * </li> 96 * <li> 97 * If the original types collectively have only one abstract method, or have several of them, but all share the 98 * same name, an additional constructor for instance-level override adapter is provided for every original constructor; 99 * this one takes a ScriptFunction as its last argument preceded by original constructor arguments. This constructor 100 * will use the passed function as the implementation for all abstract methods. For consistency, any concrete methods 101 * sharing the single abstract method name will also be overridden by the function. When methods on the adapter instance 102 * are invoked, the ScriptFunction is invoked with UNDEFINED or Global as its "this" depending whether the function is 103 * strict or not. 104 * </li> 105 * <li> 106 * If the adapter being generated has class-level overrides, constructors taking same arguments as the superclass 107 * constructors are created. These constructors simply delegate to the superclass constructor. They are simply used to 108 * create instances of the adapter class, with no instance-level overrides, as they don't have them. If the original 109 * class' constructor was variable arity, the adapter constructor will also be variable arity. Protected constructors 110 * are exposed as public. 111 * </li> 112 * </ul> 113 * </p><p> 114 * For adapter methods that return values, all the JavaScript-to-Java conversions supported by Nashorn will be in effect 115 * to coerce the JavaScript function return value to the expected Java return type. 116 * </p><p> 117 * Since we are adding a trailing argument to the generated constructors in the adapter class with instance-level overrides, they will never be 118 * declared as variable arity, even if the original constructor in the superclass was declared as variable arity. The 119 * reason we are passing the additional argument at the end of the argument list instead at the front is that the 120 * source-level script expression <code>new X(a, b) { ... }</code> (which is a proprietary syntax extension Nashorn uses 121 * to resemble Java anonymous classes) is actually equivalent to <code>new X(a, b, { ... })</code>. 122 * </p><p> 123 * It is possible to create two different adapter classes: those that can have class-level overrides, and those that can 124 * have instance-level overrides. When {@link JavaAdapterFactory#getAdapterClassFor(Class[], ScriptObject)} is invoked 125 * with non-null {@code classOverrides} parameter, an adapter class is created that can have class-level overrides, and 126 * the passed script object will be used as the implementations for its methods, just as in the above case of the 127 * constructor taking a script object. Note that in the case of class-level overrides, a new adapter class is created on 128 * every invocation, and the implementation object is bound to the class, not to any instance. All created instances 129 * will share these functions. If it is required to have both class-level overrides and instance-level overrides, the 130 * class-level override adapter class should be subclassed with an instance-override adapter. Since adapters delegate to 131 * super class when an overriding method handle is not specified, this will behave as expected. It is not possible to 132 * have both class-level and instance-level overrides in the same class for security reasons: adapter classes are 133 * defined with a protection domain of their creator code, and an adapter class that has both class and instance level 134 * overrides would need to have two potentially different protection domains: one for class-based behavior and one for 135 * instance-based behavior; since Java classes can only belong to a single protection domain, this could not be 136 * implemented securely. 137 */ 138final class JavaAdapterBytecodeGenerator { 139 // Field names in adapters 140 private static final String GLOBAL_FIELD_NAME = "global"; 141 private static final String DELEGATE_FIELD_NAME = "delegate"; 142 private static final String IS_FUNCTION_FIELD_NAME = "isFunction"; 143 private static final String CALL_THIS_FIELD_NAME = "callThis"; 144 145 // Initializer names 146 private static final String INIT = "<init>"; 147 private static final String CLASS_INIT = "<clinit>"; 148 149 // Types often used in generated bytecode 150 private static final Type OBJECT_TYPE = Type.getType(Object.class); 151 private static final Type SCRIPT_OBJECT_TYPE = Type.getType(ScriptObject.class); 152 private static final Type SCRIPT_FUNCTION_TYPE = Type.getType(ScriptFunction.class); 153 154 // JavaAdapterServices methods used in generated bytecode 155 private static final Call CHECK_FUNCTION = lookupServiceMethod("checkFunction", ScriptFunction.class, Object.class, String.class); 156 private static final Call EXPORT_RETURN_VALUE = lookupServiceMethod("exportReturnValue", Object.class, Object.class); 157 private static final Call GET_CALL_THIS = lookupServiceMethod("getCallThis", Object.class, ScriptFunction.class, Object.class); 158 private static final Call GET_CLASS_OVERRIDES = lookupServiceMethod("getClassOverrides", ScriptObject.class); 159 private static final Call GET_NON_NULL_GLOBAL = lookupServiceMethod("getNonNullGlobal", ScriptObject.class); 160 private static final Call HAS_OWN_TO_STRING = lookupServiceMethod("hasOwnToString", boolean.class, ScriptObject.class); 161 private static final Call INVOKE_NO_PERMISSIONS = lookupServiceMethod("invokeNoPermissions", void.class, MethodHandle.class, Object.class); 162 private static final Call NOT_AN_OBJECT = lookupServiceMethod("notAnObject", void.class, Object.class); 163 private static final Call SET_GLOBAL = lookupServiceMethod("setGlobal", Runnable.class, ScriptObject.class); 164 private static final Call TO_CHAR_PRIMITIVE = lookupServiceMethod("toCharPrimitive", char.class, Object.class); 165 private static final Call UNSUPPORTED = lookupServiceMethod("unsupported", UnsupportedOperationException.class); 166 private static final Call WRAP_THROWABLE = lookupServiceMethod("wrapThrowable", RuntimeException.class, Throwable.class); 167 168 // Other methods invoked by the generated bytecode 169 private static final Call UNWRAP = staticCallNoLookup(ScriptUtils.class, "unwrap", Object.class, Object.class); 170 private static final Call CHAR_VALUE_OF = staticCallNoLookup(Character.class, "valueOf", Character.class, char.class); 171 private static final Call DOUBLE_VALUE_OF = staticCallNoLookup(Double.class, "valueOf", Double.class, double.class); 172 private static final Call LONG_VALUE_OF = staticCallNoLookup(Long.class, "valueOf", Long.class, long.class); 173 private static final Call RUN = interfaceCallNoLookup(Runnable.class, "run", void.class); 174 175 // ASM handle to the bootstrap method 176 private static final Handle BOOTSTRAP_HANDLE = new Handle(H_INVOKESTATIC, 177 Type.getInternalName(JavaAdapterServices.class), "bootstrap", 178 MethodType.methodType(CallSite.class, Lookup.class, String.class, 179 MethodType.class, int.class).toMethodDescriptorString()); 180 181 // ASM handle to the bootstrap method for array populator 182 private static final Handle CREATE_ARRAY_BOOTSTRAP_HANDLE = new Handle(H_INVOKESTATIC, 183 Type.getInternalName(JavaAdapterServices.class), "createArrayBootstrap", 184 MethodType.methodType(CallSite.class, Lookup.class, String.class, 185 MethodType.class).toMethodDescriptorString()); 186 187 // Field type names used in the generated bytecode 188 private static final String SCRIPT_OBJECT_TYPE_DESCRIPTOR = SCRIPT_OBJECT_TYPE.getDescriptor(); 189 private static final String OBJECT_TYPE_DESCRIPTOR = OBJECT_TYPE.getDescriptor(); 190 private static final String BOOLEAN_TYPE_DESCRIPTOR = Type.BOOLEAN_TYPE.getDescriptor(); 191 192 // Throwable names used in the generated bytecode 193 private static final String RUNTIME_EXCEPTION_TYPE_NAME = Type.getInternalName(RuntimeException.class); 194 private static final String ERROR_TYPE_NAME = Type.getInternalName(Error.class); 195 private static final String THROWABLE_TYPE_NAME = Type.getInternalName(Throwable.class); 196 197 // Some more frequently used method descriptors 198 private static final String GET_METHOD_PROPERTY_METHOD_DESCRIPTOR = Type.getMethodDescriptor(OBJECT_TYPE, SCRIPT_OBJECT_TYPE); 199 private static final String VOID_METHOD_DESCRIPTOR = Type.getMethodDescriptor(Type.VOID_TYPE); 200 201 static final String ADAPTER_PACKAGE_INTERNAL = "jdk/nashorn/javaadapters/"; 202 static final String ADAPTER_PACKAGE = "jdk.nashorn.javaadapters"; 203 private static final int MAX_GENERATED_TYPE_NAME_LENGTH = 255; 204 205 // Method name prefix for invoking super-methods 206 static final String SUPER_PREFIX = "super$"; 207 208 // Method name and type for the no-privilege finalizer delegate 209 private static final String FINALIZER_DELEGATE_NAME = "$$nashornFinalizerDelegate"; 210 private static final String FINALIZER_DELEGATE_METHOD_DESCRIPTOR = Type.getMethodDescriptor(Type.VOID_TYPE, OBJECT_TYPE); 211 212 /** 213 * Collection of methods we never override: Object.clone(), Object.finalize(). 214 */ 215 private static final Collection<MethodInfo> EXCLUDED = getExcludedMethods(); 216 217 // This is the superclass for our generated adapter. 218 private final Class<?> superClass; 219 // Interfaces implemented by our generated adapter. 220 private final List<Class<?>> interfaces; 221 // Class loader used as the parent for the class loader we'll create to load the generated class. It will be a class 222 // loader that has the visibility of all original types (class to extend and interfaces to implement) and of the 223 // Nashorn classes. 224 private final ClassLoader commonLoader; 225 // Is this a generator for the version of the class that can have overrides on the class level? 226 private final boolean classOverride; 227 // Binary name of the superClass 228 private final String superClassName; 229 // Binary name of the generated class. 230 private final String generatedClassName; 231 private final Set<String> abstractMethodNames = new HashSet<>(); 232 private final String samName; 233 private final Set<MethodInfo> finalMethods = new HashSet<>(EXCLUDED); 234 private final Set<MethodInfo> methodInfos = new HashSet<>(); 235 private final boolean autoConvertibleFromFunction; 236 private boolean hasExplicitFinalizer = false; 237 private final Set<Module> accessedModules = new HashSet<>(); 238 239 private final ClassWriter cw; 240 241 /** 242 * Creates a generator for the bytecode for the adapter for the specified superclass and interfaces. 243 * @param superClass the superclass the adapter will extend. 244 * @param interfaces the interfaces the adapter will implement. 245 * @param commonLoader the class loader that can see all of superClass, interfaces, and Nashorn classes. 246 * @param classOverride true to generate the bytecode for the adapter that has class-level overrides, false to 247 * generate the bytecode for the adapter that has instance-level overrides. 248 * @throws AdaptationException if the adapter can not be generated for some reason. 249 */ 250 JavaAdapterBytecodeGenerator(final Class<?> superClass, final List<Class<?>> interfaces, 251 final ClassLoader commonLoader, final boolean classOverride) throws AdaptationException { 252 assert superClass != null && !superClass.isInterface(); 253 assert interfaces != null; 254 255 this.superClass = superClass; 256 this.interfaces = interfaces; 257 this.classOverride = classOverride; 258 this.commonLoader = commonLoader; 259 cw = new ClassWriter(ClassWriter.COMPUTE_FRAMES | ClassWriter.COMPUTE_MAXS) { 260 @Override 261 protected String getCommonSuperClass(final String type1, final String type2) { 262 // We need to override ClassWriter.getCommonSuperClass to use this factory's commonLoader as a class 263 // loader to find the common superclass of two types when needed. 264 return JavaAdapterBytecodeGenerator.this.getCommonSuperClass(type1, type2); 265 } 266 }; 267 superClassName = Type.getInternalName(superClass); 268 generatedClassName = getGeneratedClassName(superClass, interfaces); 269 270 cw.visit(Opcodes.V1_7, ACC_PUBLIC | ACC_SUPER, generatedClassName, null, superClassName, getInternalTypeNames(interfaces)); 271 generateField(GLOBAL_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR); 272 generateField(DELEGATE_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR); 273 274 gatherMethods(superClass); 275 gatherMethods(interfaces); 276 if (abstractMethodNames.size() == 1) { 277 samName = abstractMethodNames.iterator().next(); 278 generateField(CALL_THIS_FIELD_NAME, OBJECT_TYPE_DESCRIPTOR); 279 generateField(IS_FUNCTION_FIELD_NAME, BOOLEAN_TYPE_DESCRIPTOR); 280 } else { 281 samName = null; 282 } 283 if(classOverride) { 284 generateClassInit(); 285 } 286 autoConvertibleFromFunction = generateConstructors(); 287 generateMethods(); 288 generateSuperMethods(); 289 if (hasExplicitFinalizer) { 290 generateFinalizerMethods(); 291 } 292 // } 293 cw.visitEnd(); 294 } 295 296 private void generateField(final String name, final String fieldDesc) { 297 cw.visitField(ACC_PRIVATE | ACC_FINAL | (classOverride ? ACC_STATIC : 0), name, fieldDesc, null, null).visitEnd(); 298 } 299 300 JavaAdapterClassLoader createAdapterClassLoader() { 301 return new JavaAdapterClassLoader(generatedClassName, cw.toByteArray(), accessedModules); 302 } 303 304 boolean isAutoConvertibleFromFunction() { 305 return autoConvertibleFromFunction; 306 } 307 308 private static String getGeneratedClassName(final Class<?> superType, final List<Class<?>> interfaces) { 309 // The class we use to primarily name our adapter is either the superclass, or if it is Object (meaning we're 310 // just implementing interfaces or extending Object), then the first implemented interface or Object. 311 final Class<?> namingType = superType == Object.class ? (interfaces.isEmpty()? Object.class : interfaces.get(0)) : superType; 312 final Package pkg = namingType.getPackage(); 313 final String namingTypeName = Type.getInternalName(namingType); 314 final StringBuilder buf = new StringBuilder(); 315 buf.append(ADAPTER_PACKAGE_INTERNAL).append(namingTypeName.replace('/', '_')); 316 final Iterator<Class<?>> it = interfaces.iterator(); 317 if(superType == Object.class && it.hasNext()) { 318 it.next(); // Skip first interface, it was used to primarily name the adapter 319 } 320 // Append interface names to the adapter name 321 while(it.hasNext()) { 322 buf.append("$$").append(it.next().getSimpleName()); 323 } 324 return buf.toString().substring(0, Math.min(MAX_GENERATED_TYPE_NAME_LENGTH, buf.length())); 325 } 326 327 /** 328 * Given a list of class objects, return an array with their binary names. Used to generate the array of interface 329 * names to implement. 330 * @param classes the classes 331 * @return an array of names 332 */ 333 private static String[] getInternalTypeNames(final List<Class<?>> classes) { 334 final int interfaceCount = classes.size(); 335 final String[] interfaceNames = new String[interfaceCount]; 336 for(int i = 0; i < interfaceCount; ++i) { 337 interfaceNames[i] = Type.getInternalName(classes.get(i)); 338 } 339 return interfaceNames; 340 } 341 342 private void generateClassInit() { 343 final InstructionAdapter mv = new InstructionAdapter(cw.visitMethod(ACC_STATIC, CLASS_INIT, 344 VOID_METHOD_DESCRIPTOR, null, null)); 345 346 // Assign "global = Context.getGlobal()" 347 GET_NON_NULL_GLOBAL.invoke(mv); 348 mv.putstatic(generatedClassName, GLOBAL_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR); 349 350 GET_CLASS_OVERRIDES.invoke(mv); 351 if(samName != null) { 352 // If the class is a SAM, allow having ScriptFunction passed as class overrides 353 mv.dup(); 354 mv.instanceOf(SCRIPT_FUNCTION_TYPE); 355 mv.dup(); 356 mv.putstatic(generatedClassName, IS_FUNCTION_FIELD_NAME, BOOLEAN_TYPE_DESCRIPTOR); 357 final Label notFunction = new Label(); 358 mv.ifeq(notFunction); 359 mv.dup(); 360 mv.checkcast(SCRIPT_FUNCTION_TYPE); 361 emitInitCallThis(mv); 362 mv.visitLabel(notFunction); 363 } 364 mv.putstatic(generatedClassName, DELEGATE_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR); 365 366 endInitMethod(mv); 367 } 368 369 /** 370 * Emit bytecode for initializing the "callThis" field. 371 */ 372 private void emitInitCallThis(final InstructionAdapter mv) { 373 loadField(mv, GLOBAL_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR); 374 GET_CALL_THIS.invoke(mv); 375 if(classOverride) { 376 mv.putstatic(generatedClassName, CALL_THIS_FIELD_NAME, OBJECT_TYPE_DESCRIPTOR); 377 } else { 378 // It is presumed ALOAD 0 was already executed 379 mv.putfield(generatedClassName, CALL_THIS_FIELD_NAME, OBJECT_TYPE_DESCRIPTOR); 380 } 381 } 382 383 private boolean generateConstructors() throws AdaptationException { 384 boolean gotCtor = false; 385 boolean canBeAutoConverted = false; 386 for (final Constructor<?> ctor: superClass.getDeclaredConstructors()) { 387 final int modifier = ctor.getModifiers(); 388 if((modifier & (Modifier.PUBLIC | Modifier.PROTECTED)) != 0 && !isCallerSensitive(ctor)) { 389 canBeAutoConverted = generateConstructors(ctor) | canBeAutoConverted; 390 gotCtor = true; 391 } 392 } 393 if(!gotCtor) { 394 throw new AdaptationException(ERROR_NO_ACCESSIBLE_CONSTRUCTOR, superClass.getCanonicalName()); 395 } 396 return canBeAutoConverted; 397 } 398 399 private boolean generateConstructors(final Constructor<?> ctor) { 400 for (final Class<?> pt : ctor.getParameterTypes()) { 401 if (pt.isPrimitive()) continue; 402 final Module ptMod = pt.getModule(); 403 if (ptMod != null) { 404 accessedModules.add(ptMod); 405 } 406 } 407 408 if(classOverride) { 409 // Generate a constructor that just delegates to ctor. This is used with class-level overrides, when we want 410 // to create instances without further per-instance overrides. 411 generateDelegatingConstructor(ctor); 412 return false; 413 } 414 415 // Generate a constructor that delegates to ctor, but takes an additional ScriptObject parameter at the 416 // beginning of its parameter list. 417 generateOverridingConstructor(ctor, false); 418 419 if (samName == null) { 420 return false; 421 } 422 // If all our abstract methods have a single name, generate an additional constructor, one that takes a 423 // ScriptFunction as its first parameter and assigns it as the implementation for all abstract methods. 424 generateOverridingConstructor(ctor, true); 425 // If the original type only has a single abstract method name, as well as a default ctor, then it can 426 // be automatically converted from JS function. 427 return ctor.getParameterTypes().length == 0; 428 } 429 430 private void generateDelegatingConstructor(final Constructor<?> ctor) { 431 final Type originalCtorType = Type.getType(ctor); 432 final Type[] argTypes = originalCtorType.getArgumentTypes(); 433 434 // All constructors must be public, even if in the superclass they were protected. 435 final InstructionAdapter mv = new InstructionAdapter(cw.visitMethod(ACC_PUBLIC | 436 (ctor.isVarArgs() ? ACC_VARARGS : 0), INIT, 437 Type.getMethodDescriptor(originalCtorType.getReturnType(), argTypes), null, null)); 438 439 mv.visitCode(); 440 emitSuperConstructorCall(mv, originalCtorType.getDescriptor()); 441 442 endInitMethod(mv); 443 } 444 445 /** 446 * Generates a constructor for the instance adapter class. This constructor will take the same arguments as the supertype 447 * constructor passed as the argument here, and delegate to it. However, it will take an additional argument of 448 * either ScriptObject or ScriptFunction type (based on the value of the "fromFunction" parameter), and initialize 449 * all the method handle fields of the adapter instance with functions from the script object (or the script 450 * function itself, if that's what's passed). There is one method handle field in the adapter class for every method 451 * that can be implemented or overridden; the name of every field is same as the name of the method, with a number 452 * suffix that makes it unique in case of overloaded methods. The generated constructor will invoke 453 * {@link #getHandle(ScriptFunction, MethodType, boolean)} or {@link #getHandle(Object, String, MethodType, 454 * boolean)} to obtain the method handles; these methods make sure to add the necessary conversions and arity 455 * adjustments so that the resulting method handles can be invoked from generated methods using {@code invokeExact}. 456 * The constructor that takes a script function will only initialize the methods with the same name as the single 457 * abstract method. The constructor will also store the Nashorn global that was current at the constructor 458 * invocation time in a field named "global". The generated constructor will be public, regardless of whether the 459 * supertype constructor was public or protected. The generated constructor will not be variable arity, even if the 460 * supertype constructor was. 461 * @param ctor the supertype constructor that is serving as the base for the generated constructor. 462 * @param fromFunction true if we're generating a constructor that initializes SAM types from a single 463 * ScriptFunction passed to it, false if we're generating a constructor that initializes an arbitrary type from a 464 * ScriptObject passed to it. 465 */ 466 private void generateOverridingConstructor(final Constructor<?> ctor, final boolean fromFunction) { 467 final Type originalCtorType = Type.getType(ctor); 468 final Type[] originalArgTypes = originalCtorType.getArgumentTypes(); 469 final int argLen = originalArgTypes.length; 470 final Type[] newArgTypes = new Type[argLen + 1]; 471 472 // Insert ScriptFunction|ScriptObject as the last argument to the constructor 473 final Type extraArgumentType = fromFunction ? SCRIPT_FUNCTION_TYPE : SCRIPT_OBJECT_TYPE; 474 newArgTypes[argLen] = extraArgumentType; 475 System.arraycopy(originalArgTypes, 0, newArgTypes, 0, argLen); 476 477 // All constructors must be public, even if in the superclass they were protected. 478 // Existing super constructor <init>(this, args...) triggers generating <init>(this, args..., delegate). 479 // Any variable arity constructors become fixed-arity with explicit array arguments. 480 final InstructionAdapter mv = new InstructionAdapter(cw.visitMethod(ACC_PUBLIC, INIT, 481 Type.getMethodDescriptor(originalCtorType.getReturnType(), newArgTypes), null, null)); 482 483 mv.visitCode(); 484 // First, invoke super constructor with original arguments. 485 final int extraArgOffset = emitSuperConstructorCall(mv, originalCtorType.getDescriptor()); 486 487 // Assign "this.global = Context.getGlobal()" 488 mv.visitVarInsn(ALOAD, 0); 489 GET_NON_NULL_GLOBAL.invoke(mv); 490 mv.putfield(generatedClassName, GLOBAL_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR); 491 492 // Assign "this.delegate = delegate" 493 mv.visitVarInsn(ALOAD, 0); 494 mv.visitVarInsn(ALOAD, extraArgOffset); 495 mv.putfield(generatedClassName, DELEGATE_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR); 496 497 if (fromFunction) { 498 // Assign "isFunction = true" 499 mv.visitVarInsn(ALOAD, 0); 500 mv.iconst(1); 501 mv.putfield(generatedClassName, IS_FUNCTION_FIELD_NAME, BOOLEAN_TYPE_DESCRIPTOR); 502 503 mv.visitVarInsn(ALOAD, 0); 504 mv.visitVarInsn(ALOAD, extraArgOffset); 505 emitInitCallThis(mv); 506 } 507 508 endInitMethod(mv); 509 510 if (! fromFunction) { 511 newArgTypes[argLen] = OBJECT_TYPE; 512 final InstructionAdapter mv2 = new InstructionAdapter(cw.visitMethod(ACC_PUBLIC, INIT, 513 Type.getMethodDescriptor(originalCtorType.getReturnType(), newArgTypes), null, null)); 514 generateOverridingConstructorWithObjectParam(mv2, originalCtorType.getDescriptor()); 515 } 516 } 517 518 // Object additional param accepting constructor - generated to handle null and undefined value 519 // for script adapters. This is effectively to throw TypeError on such script adapters. See 520 // JavaAdapterServices.getHandle as well. 521 private void generateOverridingConstructorWithObjectParam(final InstructionAdapter mv, final String ctorDescriptor) { 522 mv.visitCode(); 523 final int extraArgOffset = emitSuperConstructorCall(mv, ctorDescriptor); 524 mv.visitVarInsn(ALOAD, extraArgOffset); 525 NOT_AN_OBJECT.invoke(mv); 526 endInitMethod(mv); 527 } 528 529 private static void endInitMethod(final InstructionAdapter mv) { 530 mv.visitInsn(RETURN); 531 endMethod(mv); 532 } 533 534 private static void endMethod(final InstructionAdapter mv) { 535 mv.visitMaxs(0, 0); 536 mv.visitEnd(); 537 } 538 539 /** 540 * Encapsulation of the information used to generate methods in the adapter classes. Basically, a wrapper around the 541 * reflective Method object, a cached MethodType, and the name of the field in the adapter class that will hold the 542 * method handle serving as the implementation of this method in adapter instances. 543 * 544 */ 545 private static class MethodInfo { 546 private final Method method; 547 private final MethodType type; 548 549 private MethodInfo(final Class<?> clazz, final String name, final Class<?>... argTypes) throws NoSuchMethodException { 550 this(clazz.getDeclaredMethod(name, argTypes)); 551 } 552 553 private MethodInfo(final Method method) { 554 this.method = method; 555 this.type = MH.type(method.getReturnType(), method.getParameterTypes()); 556 } 557 558 @Override 559 public boolean equals(final Object obj) { 560 return obj instanceof MethodInfo && equals((MethodInfo)obj); 561 } 562 563 private boolean equals(final MethodInfo other) { 564 // Only method name and type are used for comparison; method handle field name is not. 565 return getName().equals(other.getName()) && type.equals(other.type); 566 } 567 568 String getName() { 569 return method.getName(); 570 } 571 572 @Override 573 public int hashCode() { 574 return getName().hashCode() ^ type.hashCode(); 575 } 576 } 577 578 private void generateMethods() { 579 for(final MethodInfo mi: methodInfos) { 580 generateMethod(mi); 581 } 582 } 583 584 /** 585 * Generates a method in the adapter class that adapts a method from the 586 * original class. The generated method will either invoke the delegate 587 * using a CALL dynamic operation call site (if it is a SAM method and the 588 * delegate is a ScriptFunction), or invoke GET_METHOD_PROPERTY dynamic 589 * operation with the method name as the argument and then invoke the 590 * returned ScriptFunction using the CALL dynamic operation. If 591 * GET_METHOD_PROPERTY returns null or undefined (that is, the JS object 592 * doesn't provide an implementation for the method) then the method will 593 * either do a super invocation to base class, or if the method is abstract, 594 * throw an {@link UnsupportedOperationException}. Finally, if 595 * GET_METHOD_PROPERTY returns something other than a ScriptFunction, null, 596 * or undefined, a TypeError is thrown. The current Global is checked before 597 * the dynamic operations, and if it is different than the Global used to 598 * create the adapter, the creating Global is set to be the current Global. 599 * In this case, the previously current Global is restored after the 600 * invocation. If CALL results in a Throwable that is not one of the 601 * method's declared exceptions, and is not an unchecked throwable, then it 602 * is wrapped into a {@link RuntimeException} and the runtime exception is 603 * thrown. 604 * @param mi the method info describing the method to be generated. 605 */ 606 private void generateMethod(final MethodInfo mi) { 607 final Method method = mi.method; 608 final Class<?>[] exceptions = method.getExceptionTypes(); 609 final String[] exceptionNames = getExceptionNames(exceptions); 610 final MethodType type = mi.type; 611 final String methodDesc = type.toMethodDescriptorString(); 612 final String name = mi.getName(); 613 614 final Type asmType = Type.getMethodType(methodDesc); 615 final Type[] asmArgTypes = asmType.getArgumentTypes(); 616 617 final InstructionAdapter mv = new InstructionAdapter(cw.visitMethod(getAccessModifiers(method), name, 618 methodDesc, null, exceptionNames)); 619 mv.visitCode(); 620 621 final Class<?> returnType = type.returnType(); 622 final Type asmReturnType = Type.getType(returnType); 623 624 // Determine the first index for a local variable 625 int nextLocalVar = 1; // "this" is at 0 626 for(final Type t: asmArgTypes) { 627 nextLocalVar += t.getSize(); 628 } 629 // Set our local variable index 630 final int globalRestoringRunnableVar = nextLocalVar++; 631 632 // Load the creatingGlobal object 633 loadField(mv, GLOBAL_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR); 634 635 // stack: [creatingGlobal] 636 SET_GLOBAL.invoke(mv); 637 // stack: [runnable] 638 mv.visitVarInsn(ASTORE, globalRestoringRunnableVar); 639 // stack: [] 640 641 final Label tryBlockStart = new Label(); 642 mv.visitLabel(tryBlockStart); 643 644 final Label callCallee = new Label(); 645 final Label defaultBehavior = new Label(); 646 // If this is a SAM type... 647 if (samName != null) { 648 // ...every method will be checking whether we're initialized with a 649 // function. 650 loadField(mv, IS_FUNCTION_FIELD_NAME, BOOLEAN_TYPE_DESCRIPTOR); 651 // stack: [isFunction] 652 if (name.equals(samName)) { 653 final Label notFunction = new Label(); 654 mv.ifeq(notFunction); 655 // stack: [] 656 // If it's a SAM method, it'll load delegate as the "callee" and 657 // "callThis" as "this" for the call if delegate is a function. 658 loadField(mv, DELEGATE_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR); 659 // NOTE: if we added "mv.checkcast(SCRIPT_FUNCTION_TYPE);" here 660 // we could emit the invokedynamic CALL instruction with signature 661 // (ScriptFunction, Object, ...) instead of (Object, Object, ...). 662 // We could combine this with an optimization in 663 // ScriptFunction.findCallMethod where it could link a call with a 664 // thinner guard when the call site statically guarantees that the 665 // callee argument is a ScriptFunction. Additionally, we could use 666 // a "ScriptFunction function" field in generated classes instead 667 // of a "boolean isFunction" field to avoid the checkcast. 668 loadField(mv, CALL_THIS_FIELD_NAME, OBJECT_TYPE_DESCRIPTOR); 669 // stack: [callThis, delegate] 670 mv.goTo(callCallee); 671 mv.visitLabel(notFunction); 672 } else { 673 // If it's not a SAM method, and the delegate is a function, 674 // it'll fall back to default behavior 675 mv.ifne(defaultBehavior); 676 // stack: [] 677 } 678 } 679 680 // At this point, this is either not a SAM method or the delegate is 681 // not a ScriptFunction. We need to emit a GET_METHOD_PROPERTY Nashorn 682 // invokedynamic. 683 684 if(name.equals("toString")) { 685 // Since every JS Object has a toString, we only override 686 // "String toString()" it if it's explicitly specified on the object. 687 loadField(mv, DELEGATE_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR); 688 // stack: [delegate] 689 HAS_OWN_TO_STRING.invoke(mv); 690 // stack: [hasOwnToString] 691 mv.ifeq(defaultBehavior); 692 } 693 694 loadField(mv, DELEGATE_FIELD_NAME, SCRIPT_OBJECT_TYPE_DESCRIPTOR); 695 mv.dup(); 696 // stack: [delegate, delegate] 697 final String encodedName = NameCodec.encode(name); 698 mv.visitInvokeDynamicInsn(encodedName, 699 GET_METHOD_PROPERTY_METHOD_DESCRIPTOR, BOOTSTRAP_HANDLE, 700 NashornCallSiteDescriptor.GET_METHOD_PROPERTY); 701 // stack: [callee, delegate] 702 mv.visitLdcInsn(name); 703 // stack: [name, callee, delegate] 704 CHECK_FUNCTION.invoke(mv); 705 // stack: [fnCalleeOrNull, delegate] 706 final Label hasFunction = new Label(); 707 mv.dup(); 708 // stack: [fnCalleeOrNull, fnCalleeOrNull, delegate] 709 mv.ifnonnull(hasFunction); 710 // stack: [null, delegate] 711 // If it's null or undefined, clear stack and fall back to default 712 // behavior. 713 mv.pop2(); 714 // stack: [] 715 716 // We can also arrive here from check for "delegate instanceof ScriptFunction" 717 // in a non-SAM method as well as from a check for "hasOwnToString(delegate)" 718 // for a toString delegate. 719 mv.visitLabel(defaultBehavior); 720 final Runnable emitFinally = ()->emitFinally(mv, globalRestoringRunnableVar); 721 final Label normalFinally = new Label(); 722 if(Modifier.isAbstract(method.getModifiers())) { 723 // If the super method is abstract, throw UnsupportedOperationException 724 UNSUPPORTED.invoke(mv); 725 // NOTE: no need to invoke emitFinally.run() as we're inside the 726 // tryBlockStart/tryBlockEnd range, so throwing this exception will 727 // transfer control to the rethrow handler and the finally block in it 728 // will execute. 729 mv.athrow(); 730 } else { 731 // If the super method is not abstract, delegate to it. 732 emitSuperCall(mv, method.getDeclaringClass(), name, methodDesc); 733 mv.goTo(normalFinally); 734 } 735 736 mv.visitLabel(hasFunction); 737 // stack: [callee, delegate] 738 mv.swap(); 739 // stack [delegate, callee] 740 mv.visitLabel(callCallee); 741 742 743 // Load all parameters back on stack for dynamic invocation. 744 745 int varOffset = 1; 746 // If the param list length is more than 253 slots, we can't invoke it 747 // directly as with (callee, this) it'll exceed 255. 748 final boolean isVarArgCall = getParamListLengthInSlots(asmArgTypes) > 253; 749 for (final Type t : asmArgTypes) { 750 mv.load(varOffset, t); 751 convertParam(mv, t, isVarArgCall); 752 varOffset += t.getSize(); 753 } 754 // stack: [args..., callee, delegate] 755 756 // If the resulting parameter list length is too long... 757 if (isVarArgCall) { 758 // ... we pack the parameters (except callee and this) into an array 759 // and use Nashorn vararg invocation. 760 mv.visitInvokeDynamicInsn(NameCodec.EMPTY_NAME, 761 getArrayCreatorMethodType(type).toMethodDescriptorString(), 762 CREATE_ARRAY_BOOTSTRAP_HANDLE); 763 } 764 765 // Invoke the target method handle 766 mv.visitInvokeDynamicInsn(encodedName, 767 getCallMethodType(isVarArgCall, type).toMethodDescriptorString(), 768 BOOTSTRAP_HANDLE, NashornCallSiteDescriptor.CALL); 769 // stack: [returnValue] 770 convertReturnValue(mv, returnType); 771 mv.visitLabel(normalFinally); 772 emitFinally.run(); 773 mv.areturn(asmReturnType); 774 775 // If Throwable is not declared, we need an adapter from Throwable to RuntimeException 776 final boolean throwableDeclared = isThrowableDeclared(exceptions); 777 final Label throwableHandler; 778 if (!throwableDeclared) { 779 // Add "throw new RuntimeException(Throwable)" handler for Throwable 780 throwableHandler = new Label(); 781 mv.visitLabel(throwableHandler); 782 WRAP_THROWABLE.invoke(mv); 783 // Fall through to rethrow handler 784 } else { 785 throwableHandler = null; 786 } 787 final Label rethrowHandler = new Label(); 788 mv.visitLabel(rethrowHandler); 789 // Rethrow handler for RuntimeException, Error, and all declared exception types 790 emitFinally.run(); 791 mv.athrow(); 792 793 if(throwableDeclared) { 794 mv.visitTryCatchBlock(tryBlockStart, normalFinally, rethrowHandler, THROWABLE_TYPE_NAME); 795 assert throwableHandler == null; 796 } else { 797 mv.visitTryCatchBlock(tryBlockStart, normalFinally, rethrowHandler, RUNTIME_EXCEPTION_TYPE_NAME); 798 mv.visitTryCatchBlock(tryBlockStart, normalFinally, rethrowHandler, ERROR_TYPE_NAME); 799 for(final String excName: exceptionNames) { 800 mv.visitTryCatchBlock(tryBlockStart, normalFinally, rethrowHandler, excName); 801 } 802 mv.visitTryCatchBlock(tryBlockStart, normalFinally, throwableHandler, THROWABLE_TYPE_NAME); 803 } 804 endMethod(mv); 805 } 806 807 private static MethodType getCallMethodType(final boolean isVarArgCall, final MethodType type) { 808 final Class<?>[] callParamTypes; 809 if (isVarArgCall) { 810 // Variable arity calls are always (Object callee, Object this, Object[] params) 811 callParamTypes = new Class<?>[] { Object.class, Object.class, Object[].class }; 812 } else { 813 // Adjust invocation type signature for conversions we instituted in 814 // convertParam; also, byte and short get passed as ints. 815 final Class<?>[] origParamTypes = type.parameterArray(); 816 callParamTypes = new Class<?>[origParamTypes.length + 2]; 817 callParamTypes[0] = Object.class; // callee; could be ScriptFunction.class ostensibly 818 callParamTypes[1] = Object.class; // this 819 for(int i = 0; i < origParamTypes.length; ++i) { 820 callParamTypes[i + 2] = getNashornParamType(origParamTypes[i], false); 821 } 822 } 823 return MethodType.methodType(getNashornReturnType(type.returnType()), callParamTypes); 824 } 825 826 private static MethodType getArrayCreatorMethodType(final MethodType type) { 827 final Class<?>[] callParamTypes = type.parameterArray(); 828 for(int i = 0; i < callParamTypes.length; ++i) { 829 callParamTypes[i] = getNashornParamType(callParamTypes[i], true); 830 } 831 return MethodType.methodType(Object[].class, callParamTypes); 832 } 833 834 private static Class<?> getNashornParamType(final Class<?> clazz, final boolean varArg) { 835 if (clazz == byte.class || clazz == short.class) { 836 return int.class; 837 } else if (clazz == float.class) { 838 // If using variable arity, we'll pass a Double instead of double 839 // so that floats don't extend the length of the parameter list. 840 // We return Object.class instead of Double.class though as the 841 // array collector will anyway operate on Object. 842 return varArg ? Object.class : double.class; 843 } else if (!clazz.isPrimitive() || clazz == long.class || clazz == char.class) { 844 return Object.class; 845 } 846 return clazz; 847 } 848 849 private static Class<?> getNashornReturnType(final Class<?> clazz) { 850 if (clazz == byte.class || clazz == short.class) { 851 return int.class; 852 } else if (clazz == float.class) { 853 return double.class; 854 } else if (clazz == void.class || clazz == char.class) { 855 return Object.class; 856 } 857 return clazz; 858 } 859 860 861 private void loadField(final InstructionAdapter mv, final String name, final String desc) { 862 if(classOverride) { 863 mv.getstatic(generatedClassName, name, desc); 864 } else { 865 mv.visitVarInsn(ALOAD, 0); 866 mv.getfield(generatedClassName, name, desc); 867 } 868 } 869 870 private static void convertReturnValue(final InstructionAdapter mv, final Class<?> origReturnType) { 871 if (origReturnType == void.class) { 872 mv.pop(); 873 } else if (origReturnType == Object.class) { 874 // Must hide ConsString (and potentially other internal Nashorn types) from callers 875 EXPORT_RETURN_VALUE.invoke(mv); 876 } else if (origReturnType == byte.class) { 877 mv.visitInsn(I2B); 878 } else if (origReturnType == short.class) { 879 mv.visitInsn(I2S); 880 } else if (origReturnType == float.class) { 881 mv.visitInsn(D2F); 882 } else if (origReturnType == char.class) { 883 TO_CHAR_PRIMITIVE.invoke(mv); 884 } 885 } 886 887 /** 888 * Emits instruction for converting a parameter on the top of the stack to 889 * a type that is understood by Nashorn. 890 * @param mv the current method visitor 891 * @param t the type on the top of the stack 892 * @param varArg if the invocation will be variable arity 893 */ 894 private static void convertParam(final InstructionAdapter mv, final Type t, final boolean varArg) { 895 // We perform conversions of some primitives to accommodate types that 896 // Nashorn can handle. 897 switch(t.getSort()) { 898 case Type.CHAR: 899 // Chars are boxed, as we don't know if the JS code wants to treat 900 // them as an effective "unsigned short" or as a single-char string. 901 CHAR_VALUE_OF.invoke(mv); 902 break; 903 case Type.FLOAT: 904 // Floats are widened to double. 905 mv.visitInsn(Opcodes.F2D); 906 if (varArg) { 907 // We'll be boxing everything anyway for the vararg invocation, 908 // so we might as well do it proactively here and thus not cause 909 // a widening in the number of slots, as that could even make 910 // the array creation invocation go over 255 param slots. 911 DOUBLE_VALUE_OF.invoke(mv); 912 } 913 break; 914 case Type.LONG: 915 // Longs are boxed as Nashorn can't represent them precisely as a 916 // primitive number. 917 LONG_VALUE_OF.invoke(mv); 918 break; 919 case Type.OBJECT: 920 if(t.equals(OBJECT_TYPE)) { 921 // Object can carry a ScriptObjectMirror and needs to be unwrapped 922 // before passing into a Nashorn function. 923 UNWRAP.invoke(mv); 924 } 925 break; 926 } 927 } 928 929 private static int getParamListLengthInSlots(final Type[] paramTypes) { 930 int len = paramTypes.length; 931 for(final Type t: paramTypes) { 932 final int sort = t.getSort(); 933 if (sort == Type.FLOAT || sort == Type.DOUBLE) { 934 // Floats are widened to double, so they'll take up two slots. 935 // Longs on the other hand are always boxed, so their width 936 // becomes 1 and thus they don't contribute an extra slot here. 937 ++len; 938 } 939 } 940 return len; 941 } 942 /** 943 * Emit code to restore the previous Nashorn Context when needed. 944 * @param mv the instruction adapter 945 * @param globalRestoringRunnableVar index of the local variable holding the reference to the global restoring Runnable 946 */ 947 private static void emitFinally(final InstructionAdapter mv, final int globalRestoringRunnableVar) { 948 mv.visitVarInsn(ALOAD, globalRestoringRunnableVar); 949 RUN.invoke(mv); 950 } 951 952 private static boolean isThrowableDeclared(final Class<?>[] exceptions) { 953 for (final Class<?> exception : exceptions) { 954 if (exception == Throwable.class) { 955 return true; 956 } 957 } 958 return false; 959 } 960 961 private void generateSuperMethods() { 962 for(final MethodInfo mi: methodInfos) { 963 if(!Modifier.isAbstract(mi.method.getModifiers())) { 964 generateSuperMethod(mi); 965 } 966 } 967 } 968 969 private void generateSuperMethod(final MethodInfo mi) { 970 final Method method = mi.method; 971 972 final String methodDesc = mi.type.toMethodDescriptorString(); 973 final String name = mi.getName(); 974 975 final InstructionAdapter mv = new InstructionAdapter(cw.visitMethod(getAccessModifiers(method), 976 SUPER_PREFIX + name, methodDesc, null, getExceptionNames(method.getExceptionTypes()))); 977 mv.visitCode(); 978 979 emitSuperCall(mv, method.getDeclaringClass(), name, methodDesc); 980 mv.areturn(Type.getType(mi.type.returnType())); 981 endMethod(mv); 982 } 983 984 // find the appropriate super type to use for invokespecial on the given interface 985 private Class<?> findInvokespecialOwnerFor(final Class<?> cl) { 986 assert Modifier.isInterface(cl.getModifiers()) : cl + " is not an interface"; 987 988 if (cl.isAssignableFrom(superClass)) { 989 return superClass; 990 } 991 992 for (final Class<?> iface : interfaces) { 993 if (cl.isAssignableFrom(iface)) { 994 return iface; 995 } 996 } 997 998 // we better that interface that extends the given interface! 999 throw new AssertionError("can't find the class/interface that extends " + cl); 1000 } 1001 1002 private int emitSuperConstructorCall(final InstructionAdapter mv, final String methodDesc) { 1003 return emitSuperCall(mv, null, INIT, methodDesc, true); 1004 } 1005 1006 private int emitSuperCall(final InstructionAdapter mv, final Class<?> owner, final String name, final String methodDesc) { 1007 return emitSuperCall(mv, owner, name, methodDesc, false); 1008 } 1009 1010 private int emitSuperCall(final InstructionAdapter mv, final Class<?> owner, final String name, final String methodDesc, final boolean constructor) { 1011 mv.visitVarInsn(ALOAD, 0); 1012 int nextParam = 1; 1013 final Type methodType = Type.getMethodType(methodDesc); 1014 for(final Type t: methodType.getArgumentTypes()) { 1015 mv.load(nextParam, t); 1016 nextParam += t.getSize(); 1017 } 1018 1019 // default method - non-abstract, interface method 1020 if (!constructor && Modifier.isInterface(owner.getModifiers())) { 1021 // we should call default method on the immediate "super" type - not on (possibly) 1022 // the indirectly inherited interface class! 1023 mv.invokespecial(Type.getInternalName(findInvokespecialOwnerFor(owner)), name, methodDesc, false); 1024 } else { 1025 mv.invokespecial(superClassName, name, methodDesc, false); 1026 } 1027 return nextParam; 1028 } 1029 1030 private void generateFinalizerMethods() { 1031 generateFinalizerDelegate(); 1032 generateFinalizerOverride(); 1033 } 1034 1035 private void generateFinalizerDelegate() { 1036 // Generate a delegate that will be invoked from the no-permission trampoline. Note it can be private, as we'll 1037 // refer to it with a MethodHandle constant pool entry in the overridden finalize() method (see 1038 // generateFinalizerOverride()). 1039 final InstructionAdapter mv = new InstructionAdapter(cw.visitMethod(ACC_PRIVATE | ACC_STATIC, 1040 FINALIZER_DELEGATE_NAME, FINALIZER_DELEGATE_METHOD_DESCRIPTOR, null, null)); 1041 1042 // Simply invoke super.finalize() 1043 mv.visitVarInsn(ALOAD, 0); 1044 mv.checkcast(Type.getType(generatedClassName)); 1045 mv.invokespecial(superClassName, "finalize", VOID_METHOD_DESCRIPTOR, false); 1046 1047 mv.visitInsn(RETURN); 1048 endMethod(mv); 1049 } 1050 1051 private void generateFinalizerOverride() { 1052 final InstructionAdapter mv = new InstructionAdapter(cw.visitMethod(ACC_PUBLIC, "finalize", 1053 VOID_METHOD_DESCRIPTOR, null, null)); 1054 // Overridden finalizer will take a MethodHandle to the finalizer delegating method, ... 1055 mv.aconst(new Handle(Opcodes.H_INVOKESTATIC, generatedClassName, FINALIZER_DELEGATE_NAME, 1056 FINALIZER_DELEGATE_METHOD_DESCRIPTOR)); 1057 mv.visitVarInsn(ALOAD, 0); 1058 // ...and invoke it through JavaAdapterServices.invokeNoPermissions 1059 INVOKE_NO_PERMISSIONS.invoke(mv); 1060 mv.visitInsn(RETURN); 1061 endMethod(mv); 1062 } 1063 1064 private static String[] getExceptionNames(final Class<?>[] exceptions) { 1065 final String[] exceptionNames = new String[exceptions.length]; 1066 for (int i = 0; i < exceptions.length; ++i) { 1067 exceptionNames[i] = Type.getInternalName(exceptions[i]); 1068 } 1069 return exceptionNames; 1070 } 1071 1072 private static int getAccessModifiers(final Method method) { 1073 return ACC_PUBLIC | (method.isVarArgs() ? ACC_VARARGS : 0); 1074 } 1075 1076 /** 1077 * Gathers methods that can be implemented or overridden from the specified type into this factory's 1078 * {@link #methodInfos} set. It will add all non-final, non-static methods that are either public or protected from 1079 * the type if the type itself is public. If the type is a class, the method will recursively invoke itself for its 1080 * superclass and the interfaces it implements, and add further methods that were not directly declared on the 1081 * class. 1082 * @param type the type defining the methods. 1083 */ 1084 private void gatherMethods(final Class<?> type) throws AdaptationException { 1085 if (Modifier.isPublic(type.getModifiers())) { 1086 final Module module = type.getModule(); 1087 if (module != null) { 1088 accessedModules.add(module); 1089 } 1090 1091 final Method[] typeMethods = type.isInterface() ? type.getMethods() : type.getDeclaredMethods(); 1092 1093 for (final Method typeMethod: typeMethods) { 1094 final String name = typeMethod.getName(); 1095 if(name.startsWith(SUPER_PREFIX)) { 1096 continue; 1097 } 1098 final int m = typeMethod.getModifiers(); 1099 if (Modifier.isStatic(m)) { 1100 continue; 1101 } 1102 if (Modifier.isPublic(m) || Modifier.isProtected(m)) { 1103 // Is it a "finalize()"? 1104 if(name.equals("finalize") && typeMethod.getParameterCount() == 0) { 1105 if(type != Object.class) { 1106 hasExplicitFinalizer = true; 1107 if(Modifier.isFinal(m)) { 1108 // Must be able to override an explicit finalizer 1109 throw new AdaptationException(Outcome.ERROR_FINAL_FINALIZER, type.getCanonicalName()); 1110 } 1111 } 1112 continue; 1113 } 1114 1115 for (final Class<?> pt : typeMethod.getParameterTypes()) { 1116 if (pt.isPrimitive()) continue; 1117 final Module ptMod = pt.getModule(); 1118 if (ptMod != null) { 1119 accessedModules.add(ptMod); 1120 } 1121 } 1122 1123 final Class<?> rt = typeMethod.getReturnType(); 1124 if (!rt.isPrimitive()) { 1125 final Module rtMod = rt.getModule(); 1126 if (rtMod != null) accessedModules.add(rtMod); 1127 } 1128 1129 final MethodInfo mi = new MethodInfo(typeMethod); 1130 if (Modifier.isFinal(m) || isCallerSensitive(typeMethod)) { 1131 finalMethods.add(mi); 1132 } else if (!finalMethods.contains(mi) && methodInfos.add(mi) && Modifier.isAbstract(m)) { 1133 abstractMethodNames.add(mi.getName()); 1134 } 1135 } 1136 } 1137 } 1138 // If the type is a class, visit its superclasses and declared interfaces. If it's an interface, we're done. 1139 // Needing to invoke the method recursively for a non-interface Class object is the consequence of needing to 1140 // see all declared protected methods, and Class.getDeclaredMethods() doesn't provide those declared in a 1141 // superclass. For interfaces, we used Class.getMethods(), as we're only interested in public ones there, and 1142 // getMethods() does provide those declared in a superinterface. 1143 if (!type.isInterface()) { 1144 final Class<?> superType = type.getSuperclass(); 1145 if (superType != null) { 1146 gatherMethods(superType); 1147 } 1148 for (final Class<?> itf: type.getInterfaces()) { 1149 gatherMethods(itf); 1150 } 1151 } 1152 } 1153 1154 private void gatherMethods(final List<Class<?>> classes) throws AdaptationException { 1155 for(final Class<?> c: classes) { 1156 gatherMethods(c); 1157 } 1158 } 1159 1160 private static final AccessControlContext GET_DECLARED_MEMBERS_ACC_CTXT = ClassAndLoader.createPermAccCtxt("accessDeclaredMembers"); 1161 1162 /** 1163 * Creates a collection of methods that are not final, but we still never allow them to be overridden in adapters, 1164 * as explicitly declaring them automatically is a bad idea. Currently, this means {@code Object.finalize()} and 1165 * {@code Object.clone()}. 1166 * @return a collection of method infos representing those methods that we never override in adapter classes. 1167 */ 1168 private static Collection<MethodInfo> getExcludedMethods() { 1169 return AccessController.doPrivileged(new PrivilegedAction<Collection<MethodInfo>>() { 1170 @Override 1171 public Collection<MethodInfo> run() { 1172 try { 1173 return Arrays.asList( 1174 new MethodInfo(Object.class, "finalize"), 1175 new MethodInfo(Object.class, "clone")); 1176 } catch (final NoSuchMethodException e) { 1177 throw new AssertionError(e); 1178 } 1179 } 1180 }, GET_DECLARED_MEMBERS_ACC_CTXT); 1181 } 1182 1183 private String getCommonSuperClass(final String type1, final String type2) { 1184 try { 1185 final Class<?> c1 = Class.forName(type1.replace('/', '.'), false, commonLoader); 1186 final Class<?> c2 = Class.forName(type2.replace('/', '.'), false, commonLoader); 1187 if (c1.isAssignableFrom(c2)) { 1188 return type1; 1189 } 1190 if (c2.isAssignableFrom(c1)) { 1191 return type2; 1192 } 1193 if (c1.isInterface() || c2.isInterface()) { 1194 return OBJECT_TYPE.getInternalName(); 1195 } 1196 return assignableSuperClass(c1, c2).getName().replace('.', '/'); 1197 } catch(final ClassNotFoundException e) { 1198 throw new RuntimeException(e); 1199 } 1200 } 1201 1202 private static Class<?> assignableSuperClass(final Class<?> c1, final Class<?> c2) { 1203 final Class<?> superClass = c1.getSuperclass(); 1204 return superClass.isAssignableFrom(c2) ? superClass : assignableSuperClass(superClass, c2); 1205 } 1206 1207 private static boolean isCallerSensitive(final AccessibleObject e) { 1208 return e.isAnnotationPresent(CallerSensitive.class); 1209 } 1210 1211 private static final Call lookupServiceMethod(final String name, final Class<?> rtype, final Class<?>... ptypes) { 1212 return staticCallNoLookup(JavaAdapterServices.class, name, rtype, ptypes); 1213 } 1214} 1215