Thu, 10 Sep 2015 09:59:23 +0530
8130888: Typos in nashorn sources
Reviewed-by: hannesw, mhaupt
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 */
26 package jdk.nashorn.internal.runtime.linker;
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;
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.LinkedHashMap;
60 import java.util.List;
61 import java.util.Map;
62 import java.util.Set;
63 import jdk.internal.org.objectweb.asm.ClassWriter;
64 import jdk.internal.org.objectweb.asm.Handle;
65 import jdk.internal.org.objectweb.asm.Label;
66 import jdk.internal.org.objectweb.asm.Opcodes;
67 import jdk.internal.org.objectweb.asm.Type;
68 import jdk.internal.org.objectweb.asm.commons.InstructionAdapter;
69 import jdk.nashorn.api.scripting.ScriptUtils;
70 import jdk.nashorn.internal.runtime.Context;
71 import jdk.nashorn.internal.runtime.JSType;
72 import jdk.nashorn.internal.runtime.ScriptFunction;
73 import jdk.nashorn.internal.runtime.ScriptObject;
74 import jdk.nashorn.internal.runtime.linker.AdaptationResult.Outcome;
75 import sun.reflect.CallerSensitive;
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) are not reflected in the adapter instance; the method implementations are bound to functions at
90 * constructor invocation time.
91 * {@code java.lang.Object} methods {@code equals}, {@code hashCode}, and {@code toString} can also be overridden. The
92 * only restriction is that since every JavaScript object already has a {@code toString} function through the
93 * {@code Object.prototype}, the {@code toString} in the adapter is only overridden if the passed ScriptObject has a
94 * {@code toString} function as its own property, and not inherited from a prototype. All other adapter methods can be
95 * implemented or overridden through a prototype-inherited function of the ScriptObject passed to the constructor too.
96 * </li>
97 * <li>
98 * If the original types collectively have only one abstract method, or have several of them, but all share the
99 * same name, an additional constructor for instance-level override adapter is provided for every original constructor;
100 * this one takes a ScriptFunction as its last argument preceded by original constructor arguments. This constructor
101 * will use the passed function as the implementation for all abstract methods. For consistency, any concrete methods
102 * sharing the single abstract method name will also be overridden by the function. When methods on the adapter instance
103 * are invoked, the ScriptFunction is invoked with UNDEFINED or Global as its "this" depending whether the function is
104 * strict or not.
105 * </li>
106 * <li>
107 * If the adapter being generated can have class-level overrides, constructors taking same arguments as the superclass
108 * constructors are created. These constructors simply delegate to the superclass constructor. They are simply used to
109 * create instances of the adapter class, with no instance-level overrides, as they don't have them. If the original
110 * class' constructor was variable arity, the adapter constructor will also be variable arity. Protected constructors
111 * are exposed as public.
112 * </li>
113 * </ul>
114 * </p><p>
115 * For adapter methods that return values, all the JavaScript-to-Java conversions supported by Nashorn will be in effect
116 * to coerce the JavaScript function return value to the expected Java return type.
117 * </p><p>
118 * Since we are adding a trailing argument to the generated constructors in the adapter class, they will never be
119 * declared as variable arity, even if the original constructor in the superclass was declared as variable arity. The
120 * reason we are passing the additional argument at the end of the argument list instead at the front is that the
121 * source-level script expression <code>new X(a, b) { ... }</code> (which is a proprietary syntax extension Nashorn uses
122 * to resemble Java anonymous classes) is actually equivalent to <code>new X(a, b, { ... })</code>.
123 * </p><p>
124 * It is possible to create two different adapter classes: those that can have class-level overrides, and those that can
125 * have instance-level overrides. When {@link JavaAdapterFactory#getAdapterClassFor(Class[], ScriptObject)} is invoked
126 * with non-null {@code classOverrides} parameter, an adapter class is created that can have class-level overrides, and
127 * the passed script object will be used as the implementations for its methods, just as in the above case of the
128 * constructor taking a script object. Note that in the case of class-level overrides, a new adapter class is created on
129 * every invocation, and the implementation object is bound to the class, not to any instance. All created instances
130 * will share these functions. If it is required to have both class-level overrides and instance-level overrides, the
131 * class-level override adapter class should be subclassed with an instance-override adapter. Since adapters delegate to
132 * super class when an overriding method handle is not specified, this will behave as expected. It is not possible to
133 * have both class-level and instance-level overrides in the same class for security reasons: adapter classes are
134 * defined with a protection domain of their creator code, and an adapter class that has both class and instance level
135 * overrides would need to have two potentially different protection domains: one for class-based behavior and one for
136 * instance-based behavior; since Java classes can only belong to a single protection domain, this could not be
137 * implemented securely.
138 */
139 final class JavaAdapterBytecodeGenerator {
140 private static final Type SCRIPTUTILS_TYPE = Type.getType(ScriptUtils.class);
141 private static final Type OBJECT_TYPE = Type.getType(Object.class);
142 private static final Type CLASS_TYPE = Type.getType(Class.class);
144 static final String OBJECT_TYPE_NAME = OBJECT_TYPE.getInternalName();
145 static final String SCRIPTUTILS_TYPE_NAME = SCRIPTUTILS_TYPE.getInternalName();
147 static final String INIT = "<init>";
149 static final String GLOBAL_FIELD_NAME = "global";
151 // "global" is declared as Object instead of Global - avoid static references to internal Nashorn classes when possible.
152 static final String GLOBAL_TYPE_DESCRIPTOR = OBJECT_TYPE.getDescriptor();
154 static final String SET_GLOBAL_METHOD_DESCRIPTOR = Type.getMethodDescriptor(Type.VOID_TYPE, OBJECT_TYPE);
155 static final String VOID_NOARG_METHOD_DESCRIPTOR = Type.getMethodDescriptor(Type.VOID_TYPE);
157 private static final Type SCRIPT_OBJECT_TYPE = Type.getType(ScriptObject.class);
158 private static final Type SCRIPT_FUNCTION_TYPE = Type.getType(ScriptFunction.class);
159 private static final Type STRING_TYPE = Type.getType(String.class);
160 private static final Type METHOD_TYPE_TYPE = Type.getType(MethodType.class);
161 private static final Type METHOD_HANDLE_TYPE = Type.getType(MethodHandle.class);
162 private static final String GET_HANDLE_OBJECT_DESCRIPTOR = Type.getMethodDescriptor(METHOD_HANDLE_TYPE,
163 OBJECT_TYPE, STRING_TYPE, METHOD_TYPE_TYPE);
164 private static final String GET_HANDLE_FUNCTION_DESCRIPTOR = Type.getMethodDescriptor(METHOD_HANDLE_TYPE,
165 SCRIPT_FUNCTION_TYPE, METHOD_TYPE_TYPE);
166 private static final String GET_CLASS_INITIALIZER_DESCRIPTOR = Type.getMethodDescriptor(OBJECT_TYPE);
167 private static final Type RUNTIME_EXCEPTION_TYPE = Type.getType(RuntimeException.class);
168 private static final Type THROWABLE_TYPE = Type.getType(Throwable.class);
169 private static final Type UNSUPPORTED_OPERATION_TYPE = Type.getType(UnsupportedOperationException.class);
171 private static final String SERVICES_CLASS_TYPE_NAME = Type.getInternalName(JavaAdapterServices.class);
172 private static final String RUNTIME_EXCEPTION_TYPE_NAME = RUNTIME_EXCEPTION_TYPE.getInternalName();
173 private static final String ERROR_TYPE_NAME = Type.getInternalName(Error.class);
174 private static final String THROWABLE_TYPE_NAME = THROWABLE_TYPE.getInternalName();
175 private static final String UNSUPPORTED_OPERATION_TYPE_NAME = UNSUPPORTED_OPERATION_TYPE.getInternalName();
177 private static final String METHOD_HANDLE_TYPE_DESCRIPTOR = METHOD_HANDLE_TYPE.getDescriptor();
178 private static final String GET_GLOBAL_METHOD_DESCRIPTOR = Type.getMethodDescriptor(OBJECT_TYPE);
179 private static final String GET_CLASS_METHOD_DESCRIPTOR = Type.getMethodDescriptor(CLASS_TYPE);
180 private static final String EXPORT_RETURN_VALUE_METHOD_DESCRIPTOR = Type.getMethodDescriptor(OBJECT_TYPE, OBJECT_TYPE);
181 private static final String UNWRAP_METHOD_DESCRIPTOR = Type.getMethodDescriptor(OBJECT_TYPE, OBJECT_TYPE);
182 private static final String GET_CONVERTER_METHOD_DESCRIPTOR = Type.getMethodDescriptor(METHOD_HANDLE_TYPE, CLASS_TYPE);
183 private static final String TO_CHAR_PRIMITIVE_METHOD_DESCRIPTOR = Type.getMethodDescriptor(Type.CHAR_TYPE, OBJECT_TYPE);
184 private static final String TO_STRING_METHOD_DESCRIPTOR = Type.getMethodDescriptor(STRING_TYPE, OBJECT_TYPE);
186 // Package used when the adapter can't be defined in the adaptee's package (either because it's sealed, or because
187 // it's a java.* package.
188 private static final String ADAPTER_PACKAGE_PREFIX = "jdk/nashorn/javaadapters/";
189 // Class name suffix used to append to the adaptee class name, when it can be defined in the adaptee's package.
190 private static final String ADAPTER_CLASS_NAME_SUFFIX = "$$NashornJavaAdapter";
191 private static final String JAVA_PACKAGE_PREFIX = "java/";
192 private static final int MAX_GENERATED_TYPE_NAME_LENGTH = 255;
194 private static final String CLASS_INIT = "<clinit>";
196 // Method name prefix for invoking super-methods
197 static final String SUPER_PREFIX = "super$";
199 /**
200 * Collection of methods we never override: Object.clone(), Object.finalize().
201 */
202 private static final Collection<MethodInfo> EXCLUDED = getExcludedMethods();
204 // This is the superclass for our generated adapter.
205 private final Class<?> superClass;
206 // Class loader used as the parent for the class loader we'll create to load the generated class. It will be a class
207 // loader that has the visibility of all original types (class to extend and interfaces to implement) and of the
208 // Nashorn classes.
209 private final ClassLoader commonLoader;
210 // Is this a generator for the version of the class that can have overrides on the class level?
211 private final boolean classOverride;
212 // Binary name of the superClass
213 private final String superClassName;
214 // Binary name of the generated class.
215 private final String generatedClassName;
216 private final Set<String> usedFieldNames = new HashSet<>();
217 private final Set<String> abstractMethodNames = new HashSet<>();
218 private final String samName;
219 private final Set<MethodInfo> finalMethods = new HashSet<>(EXCLUDED);
220 private final Set<MethodInfo> methodInfos = new HashSet<>();
221 private boolean autoConvertibleFromFunction = false;
222 private boolean hasExplicitFinalizer = false;
224 /**
225 * Names of static fields holding type converter method handles for return value conversion. We are emitting code
226 * for invoking these explicitly after the delegate handle is invoked, instead of doing an asType or
227 * filterReturnValue on the delegate handle, as that would create a new converter handle wrapping the function's
228 * handle for every instance of the adapter, causing the handle.invokeExact() call sites to become megamorphic.
229 */
230 private final Map<Class<?>, String> converterFields = new LinkedHashMap<>();
232 /**
233 * Subset of possible return types for all methods; namely, all possible return types of the SAM methods (we
234 * identify SAM types by having all of their abstract methods share a single name, so there can be multiple
235 * overloads with multiple return types. We use this set when emitting the constructor taking a ScriptFunction (the
236 * SAM initializer) to avoid populating converter fields that will never be used by SAM methods.
237 */
238 private final Set<Class<?>> samReturnTypes = new HashSet<>();
240 private final ClassWriter cw;
242 /**
243 * Creates a generator for the bytecode for the adapter for the specified superclass and interfaces.
244 * @param superClass the superclass the adapter will extend.
245 * @param interfaces the interfaces the adapter will implement.
246 * @param commonLoader the class loader that can see all of superClass, interfaces, and Nashorn classes.
247 * @param classOverride true to generate the bytecode for the adapter that has class-level overrides, false to
248 * generate the bytecode for the adapter that has instance-level overrides.
249 * @throws AdaptationException if the adapter can not be generated for some reason.
250 */
251 JavaAdapterBytecodeGenerator(final Class<?> superClass, final List<Class<?>> interfaces,
252 final ClassLoader commonLoader, final boolean classOverride) throws AdaptationException {
253 assert superClass != null && !superClass.isInterface();
254 assert interfaces != null;
256 this.superClass = superClass;
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);
270 cw.visit(Opcodes.V1_7, ACC_PUBLIC | ACC_SUPER, generatedClassName, null, superClassName, getInternalTypeNames(interfaces));
271 generateGlobalFields();
273 gatherMethods(superClass);
274 gatherMethods(interfaces);
275 samName = abstractMethodNames.size() == 1 ? abstractMethodNames.iterator().next() : null;
276 generateHandleFields();
277 generateConverterFields();
278 if(classOverride) {
279 generateClassInit();
280 }
281 generateConstructors();
282 generateMethods();
283 generateSuperMethods();
284 if (hasExplicitFinalizer) {
285 generateFinalizerMethods();
286 }
287 // }
288 cw.visitEnd();
289 }
291 private void generateGlobalFields() {
292 cw.visitField(ACC_PRIVATE | ACC_FINAL | (classOverride ? ACC_STATIC : 0), GLOBAL_FIELD_NAME, GLOBAL_TYPE_DESCRIPTOR, null, null).visitEnd();
293 usedFieldNames.add(GLOBAL_FIELD_NAME);
294 }
296 JavaAdapterClassLoader createAdapterClassLoader() {
297 return new JavaAdapterClassLoader(generatedClassName, cw.toByteArray());
298 }
300 boolean isAutoConvertibleFromFunction() {
301 return autoConvertibleFromFunction;
302 }
304 private static String getGeneratedClassName(final Class<?> superType, final List<Class<?>> interfaces) {
305 // The class we use to primarily name our adapter is either the superclass, or if it is Object (meaning we're
306 // just implementing interfaces or extending Object), then the first implemented interface or Object.
307 final Class<?> namingType = superType == Object.class ? (interfaces.isEmpty()? Object.class : interfaces.get(0)) : superType;
308 final Package pkg = namingType.getPackage();
309 final String namingTypeName = Type.getInternalName(namingType);
310 final StringBuilder buf = new StringBuilder();
311 if (namingTypeName.startsWith(JAVA_PACKAGE_PREFIX) || pkg == null || pkg.isSealed()) {
312 // Can't define new classes in java.* packages
313 buf.append(ADAPTER_PACKAGE_PREFIX).append(namingTypeName);
314 } else {
315 buf.append(namingTypeName).append(ADAPTER_CLASS_NAME_SUFFIX);
316 }
317 final Iterator<Class<?>> it = interfaces.iterator();
318 if(superType == Object.class && it.hasNext()) {
319 it.next(); // Skip first interface, it was used to primarily name the adapter
320 }
321 // Append interface names to the adapter name
322 while(it.hasNext()) {
323 buf.append("$$").append(it.next().getSimpleName());
324 }
325 return buf.toString().substring(0, Math.min(MAX_GENERATED_TYPE_NAME_LENGTH, buf.length()));
326 }
328 /**
329 * Given a list of class objects, return an array with their binary names. Used to generate the array of interface
330 * names to implement.
331 * @param classes the classes
332 * @return an array of names
333 */
334 private static String[] getInternalTypeNames(final List<Class<?>> classes) {
335 final int interfaceCount = classes.size();
336 final String[] interfaceNames = new String[interfaceCount];
337 for(int i = 0; i < interfaceCount; ++i) {
338 interfaceNames[i] = Type.getInternalName(classes.get(i));
339 }
340 return interfaceNames;
341 }
343 private void generateHandleFields() {
344 final int flags = ACC_PRIVATE | ACC_FINAL | (classOverride ? ACC_STATIC : 0);
345 for (final MethodInfo mi: methodInfos) {
346 cw.visitField(flags, mi.methodHandleFieldName, METHOD_HANDLE_TYPE_DESCRIPTOR, null, null).visitEnd();
347 }
348 }
350 private void generateConverterFields() {
351 final int flags = ACC_PRIVATE | ACC_FINAL | (classOverride ? ACC_STATIC : 0);
352 for (final MethodInfo mi: methodInfos) {
353 final Class<?> returnType = mi.type.returnType();
354 // Handle primitive types, Object, and String specially
355 if(!returnType.isPrimitive() && returnType != Object.class && returnType != String.class) {
356 if(!converterFields.containsKey(returnType)) {
357 final String name = nextName("convert");
358 converterFields.put(returnType, name);
359 if(mi.getName().equals(samName)) {
360 samReturnTypes.add(returnType);
361 }
362 cw.visitField(flags, name, METHOD_HANDLE_TYPE_DESCRIPTOR, null, null).visitEnd();
363 }
364 }
365 }
366 }
368 private void generateClassInit() {
369 final InstructionAdapter mv = new InstructionAdapter(cw.visitMethod(ACC_STATIC, CLASS_INIT,
370 Type.getMethodDescriptor(Type.VOID_TYPE), null, null));
372 mv.invokestatic(SERVICES_CLASS_TYPE_NAME, "getClassOverrides", GET_CLASS_INITIALIZER_DESCRIPTOR, false);
373 final Label initGlobal;
374 if(samName != null) {
375 // If the class is a SAM, allow having a ScriptFunction passed as class overrides
376 final Label notAFunction = new Label();
377 mv.dup();
378 mv.instanceOf(SCRIPT_FUNCTION_TYPE);
379 mv.ifeq(notAFunction);
380 mv.checkcast(SCRIPT_FUNCTION_TYPE);
382 // Assign MethodHandle fields through invoking getHandle() for a ScriptFunction, only assigning the SAM
383 // method(s).
384 for (final MethodInfo mi : methodInfos) {
385 if(mi.getName().equals(samName)) {
386 mv.dup();
387 loadMethodTypeAndGetHandle(mv, mi, GET_HANDLE_FUNCTION_DESCRIPTOR);
388 } else {
389 mv.visitInsn(ACONST_NULL);
390 }
391 mv.putstatic(generatedClassName, mi.methodHandleFieldName, METHOD_HANDLE_TYPE_DESCRIPTOR);
392 }
393 initGlobal = new Label();
394 mv.goTo(initGlobal);
395 mv.visitLabel(notAFunction);
396 } else {
397 initGlobal = null;
398 }
399 // Assign MethodHandle fields through invoking getHandle() for a ScriptObject
400 for (final MethodInfo mi : methodInfos) {
401 mv.dup();
402 mv.aconst(mi.getName());
403 loadMethodTypeAndGetHandle(mv, mi, GET_HANDLE_OBJECT_DESCRIPTOR);
404 mv.putstatic(generatedClassName, mi.methodHandleFieldName, METHOD_HANDLE_TYPE_DESCRIPTOR);
405 }
407 if(initGlobal != null) {
408 mv.visitLabel(initGlobal);
409 }
410 // Assign "global = Context.getGlobal()"
411 invokeGetGlobalWithNullCheck(mv);
412 mv.putstatic(generatedClassName, GLOBAL_FIELD_NAME, GLOBAL_TYPE_DESCRIPTOR);
414 generateConverterInit(mv, false);
415 endInitMethod(mv);
416 }
418 private void generateConverterInit(final InstructionAdapter mv, final boolean samOnly) {
419 assert !samOnly || !classOverride;
420 for(final Map.Entry<Class<?>, String> converterField: converterFields.entrySet()) {
421 final Class<?> returnType = converterField.getKey();
422 if(!classOverride) {
423 mv.visitVarInsn(ALOAD, 0);
424 }
426 if(samOnly && !samReturnTypes.contains(returnType)) {
427 mv.visitInsn(ACONST_NULL);
428 } else {
429 mv.aconst(Type.getType(converterField.getKey()));
430 mv.invokestatic(SERVICES_CLASS_TYPE_NAME, "getObjectConverter", GET_CONVERTER_METHOD_DESCRIPTOR, false);
431 }
433 if(classOverride) {
434 mv.putstatic(generatedClassName, converterField.getValue(), METHOD_HANDLE_TYPE_DESCRIPTOR);
435 } else {
436 mv.putfield(generatedClassName, converterField.getValue(), METHOD_HANDLE_TYPE_DESCRIPTOR);
437 }
438 }
439 }
441 private static void loadMethodTypeAndGetHandle(final InstructionAdapter mv, final MethodInfo mi, final String getHandleDescriptor) {
442 // NOTE: we're using generic() here because we'll be linking to the "generic" invoker version of
443 // the functions anyway, so we cut down on megamorphism in the invokeExact() calls in adapter
444 // bodies. Once we start linking to type-specializing invokers, this should be changed.
445 mv.aconst(Type.getMethodType(mi.type.generic().toMethodDescriptorString()));
446 mv.invokestatic(SERVICES_CLASS_TYPE_NAME, "getHandle", getHandleDescriptor, false);
447 }
449 private static void invokeGetGlobalWithNullCheck(final InstructionAdapter mv) {
450 invokeGetGlobal(mv);
451 mv.dup();
452 mv.invokevirtual(OBJECT_TYPE_NAME, "getClass", GET_CLASS_METHOD_DESCRIPTOR, false); // check against null Context
453 mv.pop();
454 }
456 private void generateConstructors() throws AdaptationException {
457 boolean gotCtor = false;
458 for (final Constructor<?> ctor: superClass.getDeclaredConstructors()) {
459 final int modifier = ctor.getModifiers();
460 if((modifier & (Modifier.PUBLIC | Modifier.PROTECTED)) != 0 && !isCallerSensitive(ctor)) {
461 generateConstructors(ctor);
462 gotCtor = true;
463 }
464 }
465 if(!gotCtor) {
466 throw new AdaptationException(ERROR_NO_ACCESSIBLE_CONSTRUCTOR, superClass.getCanonicalName());
467 }
468 }
470 private void generateConstructors(final Constructor<?> ctor) {
471 if(classOverride) {
472 // Generate a constructor that just delegates to ctor. This is used with class-level overrides, when we want
473 // to create instances without further per-instance overrides.
474 generateDelegatingConstructor(ctor);
475 } else {
476 // Generate a constructor that delegates to ctor, but takes an additional ScriptObject parameter at the
477 // beginning of its parameter list.
478 generateOverridingConstructor(ctor, false);
480 if (samName != null) {
481 if (!autoConvertibleFromFunction && ctor.getParameterTypes().length == 0) {
482 // If the original type only has a single abstract method name, as well as a default ctor, then it can
483 // be automatically converted from JS function.
484 autoConvertibleFromFunction = true;
485 }
486 // If all our abstract methods have a single name, generate an additional constructor, one that takes a
487 // ScriptFunction as its first parameter and assigns it as the implementation for all abstract methods.
488 generateOverridingConstructor(ctor, true);
489 }
490 }
491 }
493 private void generateDelegatingConstructor(final Constructor<?> ctor) {
494 final Type originalCtorType = Type.getType(ctor);
495 final Type[] argTypes = originalCtorType.getArgumentTypes();
497 // All constructors must be public, even if in the superclass they were protected.
498 final InstructionAdapter mv = new InstructionAdapter(cw.visitMethod(ACC_PUBLIC |
499 (ctor.isVarArgs() ? ACC_VARARGS : 0), INIT,
500 Type.getMethodDescriptor(originalCtorType.getReturnType(), argTypes), null, null));
502 mv.visitCode();
503 // Invoke super constructor with the same arguments.
504 mv.visitVarInsn(ALOAD, 0);
505 int offset = 1; // First arg is at position 1, after this.
506 for (final Type argType: argTypes) {
507 mv.load(offset, argType);
508 offset += argType.getSize();
509 }
510 mv.invokespecial(superClassName, INIT, originalCtorType.getDescriptor(), false);
512 endInitMethod(mv);
513 }
515 /**
516 * Generates a constructor for the instance adapter class. This constructor will take the same arguments as the supertype
517 * constructor passed as the argument here, and delegate to it. However, it will take an additional argument of
518 * either ScriptObject or ScriptFunction type (based on the value of the "fromFunction" parameter), and initialize
519 * all the method handle fields of the adapter instance with functions from the script object (or the script
520 * function itself, if that's what's passed). There is one method handle field in the adapter class for every method
521 * that can be implemented or overridden; the name of every field is same as the name of the method, with a number
522 * suffix that makes it unique in case of overloaded methods. The generated constructor will invoke
523 * {@link #getHandle(ScriptFunction, MethodType, boolean)} or {@link #getHandle(Object, String, MethodType,
524 * boolean)} to obtain the method handles; these methods make sure to add the necessary conversions and arity
525 * adjustments so that the resulting method handles can be invoked from generated methods using {@code invokeExact}.
526 * The constructor that takes a script function will only initialize the methods with the same name as the single
527 * abstract method. The constructor will also store the Nashorn global that was current at the constructor
528 * invocation time in a field named "global". The generated constructor will be public, regardless of whether the
529 * supertype constructor was public or protected. The generated constructor will not be variable arity, even if the
530 * supertype constructor was.
531 * @param ctor the supertype constructor that is serving as the base for the generated constructor.
532 * @param fromFunction true if we're generating a constructor that initializes SAM types from a single
533 * ScriptFunction passed to it, false if we're generating a constructor that initializes an arbitrary type from a
534 * ScriptObject passed to it.
535 */
536 private void generateOverridingConstructor(final Constructor<?> ctor, final boolean fromFunction) {
537 final Type originalCtorType = Type.getType(ctor);
538 final Type[] originalArgTypes = originalCtorType.getArgumentTypes();
539 final int argLen = originalArgTypes.length;
540 final Type[] newArgTypes = new Type[argLen + 1];
542 // Insert ScriptFunction|ScriptObject as the last argument to the constructor
543 final Type extraArgumentType = fromFunction ? SCRIPT_FUNCTION_TYPE : SCRIPT_OBJECT_TYPE;
544 newArgTypes[argLen] = extraArgumentType;
545 System.arraycopy(originalArgTypes, 0, newArgTypes, 0, argLen);
547 // All constructors must be public, even if in the superclass they were protected.
548 // Existing super constructor <init>(this, args...) triggers generating <init>(this, args..., scriptObj).
549 // Any variable arity constructors become fixed-arity with explicit array arguments.
550 final InstructionAdapter mv = new InstructionAdapter(cw.visitMethod(ACC_PUBLIC, INIT,
551 Type.getMethodDescriptor(originalCtorType.getReturnType(), newArgTypes), null, null));
553 mv.visitCode();
554 // First, invoke super constructor with original arguments. If the form of the constructor we're generating is
555 // <init>(this, args..., scriptFn), then we're invoking super.<init>(this, args...).
556 mv.visitVarInsn(ALOAD, 0);
557 final Class<?>[] argTypes = ctor.getParameterTypes();
558 int offset = 1; // First arg is at position 1, after this.
559 for (int i = 0; i < argLen; ++i) {
560 final Type argType = Type.getType(argTypes[i]);
561 mv.load(offset, argType);
562 offset += argType.getSize();
563 }
564 mv.invokespecial(superClassName, INIT, originalCtorType.getDescriptor(), false);
566 // Get a descriptor to the appropriate "JavaAdapterFactory.getHandle" method.
567 final String getHandleDescriptor = fromFunction ? GET_HANDLE_FUNCTION_DESCRIPTOR : GET_HANDLE_OBJECT_DESCRIPTOR;
569 // Assign MethodHandle fields through invoking getHandle()
570 for (final MethodInfo mi : methodInfos) {
571 mv.visitVarInsn(ALOAD, 0);
572 if (fromFunction && !mi.getName().equals(samName)) {
573 // Constructors initializing from a ScriptFunction only initialize methods with the SAM name.
574 // NOTE: if there's a concrete overloaded method sharing the SAM name, it'll be overridden too. This
575 // is a deliberate design choice. All other method handles are initialized to null.
576 mv.visitInsn(ACONST_NULL);
577 } else {
578 mv.visitVarInsn(ALOAD, offset);
579 if(!fromFunction) {
580 mv.aconst(mi.getName());
581 }
582 loadMethodTypeAndGetHandle(mv, mi, getHandleDescriptor);
583 }
584 mv.putfield(generatedClassName, mi.methodHandleFieldName, METHOD_HANDLE_TYPE_DESCRIPTOR);
585 }
587 // Assign "this.global = Context.getGlobal()"
588 mv.visitVarInsn(ALOAD, 0);
589 invokeGetGlobalWithNullCheck(mv);
590 mv.putfield(generatedClassName, GLOBAL_FIELD_NAME, GLOBAL_TYPE_DESCRIPTOR);
592 // Initialize converters
593 generateConverterInit(mv, fromFunction);
594 endInitMethod(mv);
596 if (! fromFunction) {
597 newArgTypes[argLen] = OBJECT_TYPE;
598 final InstructionAdapter mv2 = new InstructionAdapter(cw.visitMethod(ACC_PUBLIC, INIT,
599 Type.getMethodDescriptor(originalCtorType.getReturnType(), newArgTypes), null, null));
600 generateOverridingConstructorWithObjectParam(mv2, ctor, originalCtorType.getDescriptor());
601 }
602 }
604 // Object additional param accepting constructor - generated to handle null and undefined value
605 // for script adapters. This is effectively to throw TypeError on such script adapters. See
606 // JavaAdapterServices.getHandle as well.
607 private void generateOverridingConstructorWithObjectParam(final InstructionAdapter mv, final Constructor<?> ctor, final String ctorDescriptor) {
608 mv.visitCode();
609 mv.visitVarInsn(ALOAD, 0);
610 final Class<?>[] argTypes = ctor.getParameterTypes();
611 int offset = 1; // First arg is at position 1, after this.
612 for (int i = 0; i < argTypes.length; ++i) {
613 final Type argType = Type.getType(argTypes[i]);
614 mv.load(offset, argType);
615 offset += argType.getSize();
616 }
617 mv.invokespecial(superClassName, INIT, ctorDescriptor, false);
618 mv.visitVarInsn(ALOAD, offset);
619 mv.visitInsn(ACONST_NULL);
620 mv.visitInsn(ACONST_NULL);
621 mv.invokestatic(SERVICES_CLASS_TYPE_NAME, "getHandle", GET_HANDLE_OBJECT_DESCRIPTOR, false);
622 endInitMethod(mv);
623 }
625 private static void endInitMethod(final InstructionAdapter mv) {
626 mv.visitInsn(RETURN);
627 endMethod(mv);
628 }
630 private static void endMethod(final InstructionAdapter mv) {
631 mv.visitMaxs(0, 0);
632 mv.visitEnd();
633 }
635 private static void invokeGetGlobal(final InstructionAdapter mv) {
636 mv.invokestatic(SERVICES_CLASS_TYPE_NAME, "getGlobal", GET_GLOBAL_METHOD_DESCRIPTOR, false);
637 }
639 private static void invokeSetGlobal(final InstructionAdapter mv) {
640 mv.invokestatic(SERVICES_CLASS_TYPE_NAME, "setGlobal", SET_GLOBAL_METHOD_DESCRIPTOR, false);
641 }
643 /**
644 * Encapsulation of the information used to generate methods in the adapter classes. Basically, a wrapper around the
645 * reflective Method object, a cached MethodType, and the name of the field in the adapter class that will hold the
646 * method handle serving as the implementation of this method in adapter instances.
647 *
648 */
649 private static class MethodInfo {
650 private final Method method;
651 private final MethodType type;
652 private String methodHandleFieldName;
654 private MethodInfo(final Class<?> clazz, final String name, final Class<?>... argTypes) throws NoSuchMethodException {
655 this(clazz.getDeclaredMethod(name, argTypes));
656 }
658 private MethodInfo(final Method method) {
659 this.method = method;
660 this.type = MH.type(method.getReturnType(), method.getParameterTypes());
661 }
663 @Override
664 public boolean equals(final Object obj) {
665 return obj instanceof MethodInfo && equals((MethodInfo)obj);
666 }
668 private boolean equals(final MethodInfo other) {
669 // Only method name and type are used for comparison; method handle field name is not.
670 return getName().equals(other.getName()) && type.equals(other.type);
671 }
673 String getName() {
674 return method.getName();
675 }
677 @Override
678 public int hashCode() {
679 return getName().hashCode() ^ type.hashCode();
680 }
682 void setIsCanonical(final JavaAdapterBytecodeGenerator self) {
683 methodHandleFieldName = self.nextName(getName());
684 }
685 }
687 private String nextName(final String name) {
688 int i = 0;
689 String nextName = name;
690 while (!usedFieldNames.add(nextName)) {
691 final String ordinal = String.valueOf(i++);
692 final int maxNameLen = 255 - ordinal.length();
693 nextName = (name.length() <= maxNameLen ? name : name.substring(0, maxNameLen)).concat(ordinal);
694 }
695 return nextName;
696 }
698 private void generateMethods() {
699 for(final MethodInfo mi: methodInfos) {
700 generateMethod(mi);
701 }
702 }
704 /**
705 * Generates a method in the adapter class that adapts a method from the original class. The generated methods will
706 * inspect the method handle field assigned to them. If it is null (the JS object doesn't provide an implementation
707 * for the method) then it will either invoke its version in the supertype, or if it is abstract, throw an
708 * {@link UnsupportedOperationException}. Otherwise, if the method handle field's value is not null, the handle is
709 * invoked using invokeExact (signature polymorphic invocation as per JLS 15.12.3). Before the invocation, the
710 * current Nashorn {@link Context} is checked, and if it is different than the global used to create the adapter
711 * instance, the creating global is set to be the current global. In this case, the previously current global is
712 * restored after the invocation. If invokeExact results in a Throwable that is not one of the method's declared
713 * exceptions, and is not an unchecked throwable, then it is wrapped into a {@link RuntimeException} and the runtime
714 * exception is thrown. The method handle retrieved from the field is guaranteed to exactly match the signature of
715 * the method; this is guaranteed by the way constructors of the adapter class obtain them using
716 * {@link #getHandle(Object, String, MethodType, boolean)}.
717 * @param mi the method info describing the method to be generated.
718 */
719 private void generateMethod(final MethodInfo mi) {
720 final Method method = mi.method;
721 final Class<?>[] exceptions = method.getExceptionTypes();
722 final String[] exceptionNames = getExceptionNames(exceptions);
723 final MethodType type = mi.type;
724 final String methodDesc = type.toMethodDescriptorString();
725 final String name = mi.getName();
727 final Type asmType = Type.getMethodType(methodDesc);
728 final Type[] asmArgTypes = asmType.getArgumentTypes();
730 final InstructionAdapter mv = new InstructionAdapter(cw.visitMethod(getAccessModifiers(method), name,
731 methodDesc, null, exceptionNames));
732 mv.visitCode();
734 final Label handleDefined = new Label();
736 final Class<?> returnType = type.returnType();
737 final Type asmReturnType = Type.getType(returnType);
739 // See if we have overriding method handle defined
740 if(classOverride) {
741 mv.getstatic(generatedClassName, mi.methodHandleFieldName, METHOD_HANDLE_TYPE_DESCRIPTOR);
742 } else {
743 mv.visitVarInsn(ALOAD, 0);
744 mv.getfield(generatedClassName, mi.methodHandleFieldName, METHOD_HANDLE_TYPE_DESCRIPTOR);
745 }
746 // stack: [handle]
747 mv.visitInsn(DUP);
748 mv.visitJumpInsn(IFNONNULL, handleDefined);
750 // No handle is available, fall back to default behavior
751 if(Modifier.isAbstract(method.getModifiers())) {
752 // If the super method is abstract, throw an exception
753 mv.anew(UNSUPPORTED_OPERATION_TYPE);
754 mv.dup();
755 mv.invokespecial(UNSUPPORTED_OPERATION_TYPE_NAME, INIT, VOID_NOARG_METHOD_DESCRIPTOR, false);
756 mv.athrow();
757 } else {
758 mv.visitInsn(POP);
759 // If the super method is not abstract, delegate to it.
760 emitSuperCall(mv, method.getDeclaringClass(), name, methodDesc);
761 }
763 mv.visitLabel(handleDefined);
764 // Load the creatingGlobal object
765 if(classOverride) {
766 // If class handle is defined, load the static defining global
767 mv.getstatic(generatedClassName, GLOBAL_FIELD_NAME, GLOBAL_TYPE_DESCRIPTOR);
768 } else {
769 mv.visitVarInsn(ALOAD, 0);
770 mv.getfield(generatedClassName, GLOBAL_FIELD_NAME, GLOBAL_TYPE_DESCRIPTOR);
771 }
772 // stack: [creatingGlobal, handle]
773 final Label setupGlobal = new Label();
774 mv.visitLabel(setupGlobal);
776 // Determine the first index for a local variable
777 int nextLocalVar = 1; // "this" is at 0
778 for(final Type t: asmArgTypes) {
779 nextLocalVar += t.getSize();
780 }
781 // Set our local variable indices
782 final int currentGlobalVar = nextLocalVar++;
783 final int globalsDifferVar = nextLocalVar++;
785 mv.dup();
786 // stack: [creatingGlobal, creatingGlobal, handle]
788 // Emit code for switching to the creating global
789 // Global currentGlobal = Context.getGlobal();
790 invokeGetGlobal(mv);
791 mv.dup();
793 mv.visitVarInsn(ASTORE, currentGlobalVar);
794 // stack: [currentGlobal, creatingGlobal, creatingGlobal, handle]
795 // if(definingGlobal == currentGlobal) {
796 final Label globalsDiffer = new Label();
797 mv.ifacmpne(globalsDiffer);
798 // stack: [creatingGlobal, handle]
799 // globalsDiffer = false
800 mv.pop();
801 // stack: [handle]
802 mv.iconst(0); // false
803 // stack: [false, handle]
804 final Label invokeHandle = new Label();
805 mv.goTo(invokeHandle);
806 mv.visitLabel(globalsDiffer);
807 // } else {
808 // Context.setGlobal(definingGlobal);
809 // stack: [creatingGlobal, handle]
810 invokeSetGlobal(mv);
811 // stack: [handle]
812 // globalsDiffer = true
813 mv.iconst(1);
814 // stack: [true, handle]
816 mv.visitLabel(invokeHandle);
817 mv.visitVarInsn(ISTORE, globalsDifferVar);
818 // stack: [handle]
820 // Load all parameters back on stack for dynamic invocation. NOTE: since we're using a generic
821 // Object(Object, Object, ...) type signature for the method, we must box all arguments here.
822 int varOffset = 1;
823 for (final Type t : asmArgTypes) {
824 mv.load(varOffset, t);
825 boxStackTop(mv, t);
826 varOffset += t.getSize();
827 }
829 // Invoke the target method handle
830 final Label tryBlockStart = new Label();
831 mv.visitLabel(tryBlockStart);
832 emitInvokeExact(mv, type.generic());
833 convertReturnValue(mv, returnType, asmReturnType);
834 final Label tryBlockEnd = new Label();
835 mv.visitLabel(tryBlockEnd);
836 emitFinally(mv, currentGlobalVar, globalsDifferVar);
837 mv.areturn(asmReturnType);
839 // If Throwable is not declared, we need an adapter from Throwable to RuntimeException
840 final boolean throwableDeclared = isThrowableDeclared(exceptions);
841 final Label throwableHandler;
842 if (!throwableDeclared) {
843 // Add "throw new RuntimeException(Throwable)" handler for Throwable
844 throwableHandler = new Label();
845 mv.visitLabel(throwableHandler);
846 mv.anew(RUNTIME_EXCEPTION_TYPE);
847 mv.dupX1();
848 mv.swap();
849 mv.invokespecial(RUNTIME_EXCEPTION_TYPE_NAME, INIT, Type.getMethodDescriptor(Type.VOID_TYPE, THROWABLE_TYPE), false);
850 // Fall through to rethrow handler
851 } else {
852 throwableHandler = null;
853 }
854 final Label rethrowHandler = new Label();
855 mv.visitLabel(rethrowHandler);
856 // Rethrow handler for RuntimeException, Error, and all declared exception types
857 emitFinally(mv, currentGlobalVar, globalsDifferVar);
858 mv.athrow();
859 final Label methodEnd = new Label();
860 mv.visitLabel(methodEnd);
862 mv.visitLocalVariable("currentGlobal", GLOBAL_TYPE_DESCRIPTOR, null, setupGlobal, methodEnd, currentGlobalVar);
863 mv.visitLocalVariable("globalsDiffer", Type.BOOLEAN_TYPE.getDescriptor(), null, setupGlobal, methodEnd, globalsDifferVar);
865 if(throwableDeclared) {
866 mv.visitTryCatchBlock(tryBlockStart, tryBlockEnd, rethrowHandler, THROWABLE_TYPE_NAME);
867 assert throwableHandler == null;
868 } else {
869 mv.visitTryCatchBlock(tryBlockStart, tryBlockEnd, rethrowHandler, RUNTIME_EXCEPTION_TYPE_NAME);
870 mv.visitTryCatchBlock(tryBlockStart, tryBlockEnd, rethrowHandler, ERROR_TYPE_NAME);
871 for(final String excName: exceptionNames) {
872 mv.visitTryCatchBlock(tryBlockStart, tryBlockEnd, rethrowHandler, excName);
873 }
874 mv.visitTryCatchBlock(tryBlockStart, tryBlockEnd, throwableHandler, THROWABLE_TYPE_NAME);
875 }
876 endMethod(mv);
877 }
879 private void convertReturnValue(final InstructionAdapter mv, final Class<?> returnType, final Type asmReturnType) {
880 switch(asmReturnType.getSort()) {
881 case Type.VOID:
882 mv.pop();
883 break;
884 case Type.BOOLEAN:
885 JSType.TO_BOOLEAN.invoke(mv);
886 break;
887 case Type.BYTE:
888 JSType.TO_INT32.invoke(mv);
889 mv.visitInsn(Opcodes.I2B);
890 break;
891 case Type.SHORT:
892 JSType.TO_INT32.invoke(mv);
893 mv.visitInsn(Opcodes.I2S);
894 break;
895 case Type.CHAR:
896 // JSType doesn't have a TO_CHAR, so we have services supply us one.
897 mv.invokestatic(SERVICES_CLASS_TYPE_NAME, "toCharPrimitive", TO_CHAR_PRIMITIVE_METHOD_DESCRIPTOR, false);
898 break;
899 case Type.INT:
900 JSType.TO_INT32.invoke(mv);
901 break;
902 case Type.LONG:
903 JSType.TO_LONG.invoke(mv);
904 break;
905 case Type.FLOAT:
906 JSType.TO_NUMBER.invoke(mv);
907 mv.visitInsn(Opcodes.D2F);
908 break;
909 case Type.DOUBLE:
910 JSType.TO_NUMBER.invoke(mv);
911 break;
912 default:
913 if(asmReturnType.equals(OBJECT_TYPE)) {
914 // Must hide ConsString (and potentially other internal Nashorn types) from callers
915 mv.invokestatic(SERVICES_CLASS_TYPE_NAME, "exportReturnValue", EXPORT_RETURN_VALUE_METHOD_DESCRIPTOR, false);
916 } else if(asmReturnType.equals(STRING_TYPE)){
917 // Well-known conversion to String. Not using the JSType one as we want to preserve null as null instead
918 // of the string "n,u,l,l".
919 mv.invokestatic(SERVICES_CLASS_TYPE_NAME, "toString", TO_STRING_METHOD_DESCRIPTOR, false);
920 } else {
921 // Invoke converter method handle for everything else. Note that we could have just added an asType or
922 // filterReturnValue to the invoked handle instead, but then every instance would have the function
923 // method handle wrapped in a separate converter method handle, making handle.invokeExact() megamorphic.
924 if(classOverride) {
925 mv.getstatic(generatedClassName, converterFields.get(returnType), METHOD_HANDLE_TYPE_DESCRIPTOR);
926 } else {
927 mv.visitVarInsn(ALOAD, 0);
928 mv.getfield(generatedClassName, converterFields.get(returnType), METHOD_HANDLE_TYPE_DESCRIPTOR);
929 }
930 mv.swap();
931 emitInvokeExact(mv, MethodType.methodType(returnType, Object.class));
932 }
933 }
934 }
936 private static void emitInvokeExact(final InstructionAdapter mv, final MethodType type) {
937 mv.invokevirtual(METHOD_HANDLE_TYPE.getInternalName(), "invokeExact", type.toMethodDescriptorString(), false);
938 }
940 private static void boxStackTop(final InstructionAdapter mv, final Type t) {
941 switch(t.getSort()) {
942 case Type.BOOLEAN:
943 invokeValueOf(mv, "Boolean", 'Z');
944 break;
945 case Type.BYTE:
946 case Type.SHORT:
947 case Type.INT:
948 // bytes and shorts get boxed as integers
949 invokeValueOf(mv, "Integer", 'I');
950 break;
951 case Type.CHAR:
952 invokeValueOf(mv, "Character", 'C');
953 break;
954 case Type.FLOAT:
955 // floats get boxed as doubles
956 mv.visitInsn(Opcodes.F2D);
957 invokeValueOf(mv, "Double", 'D');
958 break;
959 case Type.LONG:
960 invokeValueOf(mv, "Long", 'J');
961 break;
962 case Type.DOUBLE:
963 invokeValueOf(mv, "Double", 'D');
964 break;
965 case Type.ARRAY:
966 case Type.METHOD:
967 // Already boxed
968 break;
969 case Type.OBJECT:
970 if(t.equals(OBJECT_TYPE)) {
971 mv.invokestatic(SCRIPTUTILS_TYPE_NAME, "unwrap", UNWRAP_METHOD_DESCRIPTOR, false);
972 }
973 break;
974 default:
975 // Not expecting anything else (e.g. VOID)
976 assert false;
977 break;
978 }
979 }
981 private static void invokeValueOf(final InstructionAdapter mv, final String boxedType, final char unboxedType) {
982 mv.invokestatic("java/lang/" + boxedType, "valueOf", "(" + unboxedType + ")Ljava/lang/" + boxedType + ";", false);
983 }
985 /**
986 * Emit code to restore the previous Nashorn Context when needed.
987 * @param mv the instruction adapter
988 * @param currentGlobalVar index of the local variable holding the reference to the current global at method
989 * entry.
990 * @param globalsDifferVar index of the boolean local variable that is true if the global needs to be restored.
991 */
992 private static void emitFinally(final InstructionAdapter mv, final int currentGlobalVar, final int globalsDifferVar) {
993 // Emit code to restore the previous Nashorn global if needed
994 mv.visitVarInsn(ILOAD, globalsDifferVar);
995 final Label skip = new Label();
996 mv.ifeq(skip);
997 mv.visitVarInsn(ALOAD, currentGlobalVar);
998 invokeSetGlobal(mv);
999 mv.visitLabel(skip);
1000 }
1002 private static boolean isThrowableDeclared(final Class<?>[] exceptions) {
1003 for (final Class<?> exception : exceptions) {
1004 if (exception == Throwable.class) {
1005 return true;
1006 }
1007 }
1008 return false;
1009 }
1011 private void generateSuperMethods() {
1012 for(final MethodInfo mi: methodInfos) {
1013 if(!Modifier.isAbstract(mi.method.getModifiers())) {
1014 generateSuperMethod(mi);
1015 }
1016 }
1017 }
1019 private void generateSuperMethod(final MethodInfo mi) {
1020 final Method method = mi.method;
1022 final String methodDesc = mi.type.toMethodDescriptorString();
1023 final String name = mi.getName();
1025 final InstructionAdapter mv = new InstructionAdapter(cw.visitMethod(getAccessModifiers(method),
1026 SUPER_PREFIX + name, methodDesc, null, getExceptionNames(method.getExceptionTypes())));
1027 mv.visitCode();
1029 emitSuperCall(mv, method.getDeclaringClass(), name, methodDesc);
1031 endMethod(mv);
1032 }
1034 private void emitSuperCall(final InstructionAdapter mv, final Class<?> owner, final String name, final String methodDesc) {
1035 mv.visitVarInsn(ALOAD, 0);
1036 int nextParam = 1;
1037 final Type methodType = Type.getMethodType(methodDesc);
1038 for(final Type t: methodType.getArgumentTypes()) {
1039 mv.load(nextParam, t);
1040 nextParam += t.getSize();
1041 }
1043 // default method - non-abstract, interface method
1044 if (Modifier.isInterface(owner.getModifiers())) {
1045 mv.invokespecial(Type.getInternalName(owner), name, methodDesc, false);
1046 } else {
1047 mv.invokespecial(superClassName, name, methodDesc, false);
1048 }
1049 mv.areturn(methodType.getReturnType());
1050 }
1052 private void generateFinalizerMethods() {
1053 final String finalizerDelegateName = nextName("access$");
1054 generateFinalizerDelegate(finalizerDelegateName);
1055 generateFinalizerOverride(finalizerDelegateName);
1056 }
1058 private void generateFinalizerDelegate(final String finalizerDelegateName) {
1059 // Generate a delegate that will be invoked from the no-permission trampoline. Note it can be private, as we'll
1060 // refer to it with a MethodHandle constant pool entry in the overridden finalize() method (see
1061 // generateFinalizerOverride()).
1062 final InstructionAdapter mv = new InstructionAdapter(cw.visitMethod(ACC_PRIVATE | ACC_STATIC,
1063 finalizerDelegateName, Type.getMethodDescriptor(Type.VOID_TYPE, OBJECT_TYPE), null, null));
1065 // Simply invoke super.finalize()
1066 mv.visitVarInsn(ALOAD, 0);
1067 mv.checkcast(Type.getType(generatedClassName));
1068 mv.invokespecial(superClassName, "finalize", Type.getMethodDescriptor(Type.VOID_TYPE), false);
1070 mv.visitInsn(RETURN);
1071 endMethod(mv);
1072 }
1074 private void generateFinalizerOverride(final String finalizerDelegateName) {
1075 final InstructionAdapter mv = new InstructionAdapter(cw.visitMethod(ACC_PUBLIC, "finalize",
1076 VOID_NOARG_METHOD_DESCRIPTOR, null, null));
1077 // Overridden finalizer will take a MethodHandle to the finalizer delegating method, ...
1078 mv.aconst(new Handle(Opcodes.H_INVOKESTATIC, generatedClassName, finalizerDelegateName,
1079 Type.getMethodDescriptor(Type.VOID_TYPE, OBJECT_TYPE)));
1080 mv.visitVarInsn(ALOAD, 0);
1081 // ...and invoke it through JavaAdapterServices.invokeNoPermissions
1082 mv.invokestatic(SERVICES_CLASS_TYPE_NAME, "invokeNoPermissions",
1083 Type.getMethodDescriptor(METHOD_HANDLE_TYPE, OBJECT_TYPE), false);
1084 mv.visitInsn(RETURN);
1085 endMethod(mv);
1086 }
1088 private static String[] getExceptionNames(final Class<?>[] exceptions) {
1089 final String[] exceptionNames = new String[exceptions.length];
1090 for (int i = 0; i < exceptions.length; ++i) {
1091 exceptionNames[i] = Type.getInternalName(exceptions[i]);
1092 }
1093 return exceptionNames;
1094 }
1096 private static int getAccessModifiers(final Method method) {
1097 return ACC_PUBLIC | (method.isVarArgs() ? ACC_VARARGS : 0);
1098 }
1100 /**
1101 * Gathers methods that can be implemented or overridden from the specified type into this factory's
1102 * {@link #methodInfos} set. It will add all non-final, non-static methods that are either public or protected from
1103 * the type if the type itself is public. If the type is a class, the method will recursively invoke itself for its
1104 * superclass and the interfaces it implements, and add further methods that were not directly declared on the
1105 * class.
1106 * @param type the type defining the methods.
1107 */
1108 private void gatherMethods(final Class<?> type) throws AdaptationException {
1109 if (Modifier.isPublic(type.getModifiers())) {
1110 final Method[] typeMethods = type.isInterface() ? type.getMethods() : type.getDeclaredMethods();
1112 for (final Method typeMethod: typeMethods) {
1113 final String name = typeMethod.getName();
1114 if(name.startsWith(SUPER_PREFIX)) {
1115 continue;
1116 }
1117 final int m = typeMethod.getModifiers();
1118 if (Modifier.isStatic(m)) {
1119 continue;
1120 }
1121 if (Modifier.isPublic(m) || Modifier.isProtected(m)) {
1122 // Is it a "finalize()"?
1123 if(name.equals("finalize") && typeMethod.getParameterCount() == 0) {
1124 if(type != Object.class) {
1125 hasExplicitFinalizer = true;
1126 if(Modifier.isFinal(m)) {
1127 // Must be able to override an explicit finalizer
1128 throw new AdaptationException(Outcome.ERROR_FINAL_FINALIZER, type.getCanonicalName());
1129 }
1130 }
1131 continue;
1132 }
1134 final MethodInfo mi = new MethodInfo(typeMethod);
1135 if (Modifier.isFinal(m) || isCallerSensitive(typeMethod)) {
1136 finalMethods.add(mi);
1137 } else if (!finalMethods.contains(mi) && methodInfos.add(mi)) {
1138 if (Modifier.isAbstract(m)) {
1139 abstractMethodNames.add(mi.getName());
1140 }
1141 mi.setIsCanonical(this);
1142 }
1143 }
1144 }
1145 }
1146 // If the type is a class, visit its superclasses and declared interfaces. If it's an interface, we're done.
1147 // Needing to invoke the method recursively for a non-interface Class object is the consequence of needing to
1148 // see all declared protected methods, and Class.getDeclaredMethods() doesn't provide those declared in a
1149 // superclass. For interfaces, we used Class.getMethods(), as we're only interested in public ones there, and
1150 // getMethods() does provide those declared in a superinterface.
1151 if (!type.isInterface()) {
1152 final Class<?> superType = type.getSuperclass();
1153 if (superType != null) {
1154 gatherMethods(superType);
1155 }
1156 for (final Class<?> itf: type.getInterfaces()) {
1157 gatherMethods(itf);
1158 }
1159 }
1160 }
1162 private void gatherMethods(final List<Class<?>> classes) throws AdaptationException {
1163 for(final Class<?> c: classes) {
1164 gatherMethods(c);
1165 }
1166 }
1168 private static final AccessControlContext GET_DECLARED_MEMBERS_ACC_CTXT = ClassAndLoader.createPermAccCtxt("accessDeclaredMembers");
1170 /**
1171 * Creates a collection of methods that are not final, but we still never allow them to be overridden in adapters,
1172 * as explicitly declaring them automatically is a bad idea. Currently, this means {@code Object.finalize()} and
1173 * {@code Object.clone()}.
1174 * @return a collection of method infos representing those methods that we never override in adapter classes.
1175 */
1176 private static Collection<MethodInfo> getExcludedMethods() {
1177 return AccessController.doPrivileged(new PrivilegedAction<Collection<MethodInfo>>() {
1178 @Override
1179 public Collection<MethodInfo> run() {
1180 try {
1181 return Arrays.asList(
1182 new MethodInfo(Object.class, "finalize"),
1183 new MethodInfo(Object.class, "clone"));
1184 } catch (final NoSuchMethodException e) {
1185 throw new AssertionError(e);
1186 }
1187 }
1188 }, GET_DECLARED_MEMBERS_ACC_CTXT);
1189 }
1191 private String getCommonSuperClass(final String type1, final String type2) {
1192 try {
1193 final Class<?> c1 = Class.forName(type1.replace('/', '.'), false, commonLoader);
1194 final Class<?> c2 = Class.forName(type2.replace('/', '.'), false, commonLoader);
1195 if (c1.isAssignableFrom(c2)) {
1196 return type1;
1197 }
1198 if (c2.isAssignableFrom(c1)) {
1199 return type2;
1200 }
1201 if (c1.isInterface() || c2.isInterface()) {
1202 return OBJECT_TYPE_NAME;
1203 }
1204 return assignableSuperClass(c1, c2).getName().replace('.', '/');
1205 } catch(final ClassNotFoundException e) {
1206 throw new RuntimeException(e);
1207 }
1208 }
1210 private static Class<?> assignableSuperClass(final Class<?> c1, final Class<?> c2) {
1211 final Class<?> superClass = c1.getSuperclass();
1212 return superClass.isAssignableFrom(c2) ? superClass : assignableSuperClass(superClass, c2);
1213 }
1215 private static boolean isCallerSensitive(final AccessibleObject e) {
1216 return e.isAnnotationPresent(CallerSensitive.class);
1217 }
1218 }