1 /*
2 * Copyright (c) 2012, 2024, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.lang.invoke;
27
28 import jdk.internal.constant.ClassOrInterfaceDescImpl;
29 import jdk.internal.misc.PreviewFeatures;
30 import jdk.internal.misc.CDS;
31 import jdk.internal.util.ClassFileDumper;
32 import sun.invoke.util.VerifyAccess;
33
34 import java.io.Serializable;
35 import java.lang.classfile.ClassBuilder;
36 import java.lang.classfile.ClassFile;
37 import java.lang.classfile.CodeBuilder;
38 import java.lang.classfile.MethodBuilder;
39 import java.lang.classfile.Opcode;
40 import java.lang.classfile.TypeKind;
41
42 import java.lang.constant.ClassDesc;
43 import java.lang.constant.ConstantDescs;
44 import java.lang.constant.MethodTypeDesc;
45 import java.lang.reflect.AccessFlag;
46 import java.lang.reflect.ClassFileFormatVersion;
47 import java.lang.reflect.Modifier;
48 import java.util.ArrayList;
49 import java.util.HashSet;
50 import java.util.LinkedHashSet;
51 import java.util.List;
52 import java.util.Set;
53 import java.util.function.Consumer;
54
55 import static java.lang.classfile.ClassFile.*;
56 import java.lang.classfile.attribute.ExceptionsAttribute;
57 import java.lang.classfile.attribute.LoadableDescriptorsAttribute;
58 import java.lang.classfile.constantpool.ClassEntry;
59 import java.lang.classfile.constantpool.ConstantPoolBuilder;
60 import java.lang.classfile.constantpool.Utf8Entry;
61
62 import static java.lang.constant.ConstantDescs.*;
63 import static java.lang.invoke.MethodHandleNatives.Constants.NESTMATE_CLASS;
64 import static java.lang.invoke.MethodHandleNatives.Constants.STRONG_LOADER_LINK;
65 import jdk.internal.constant.ConstantUtils;
66 import jdk.internal.constant.MethodTypeDescImpl;
67 import jdk.internal.vm.annotation.Stable;
68 import sun.invoke.util.Wrapper;
69
70 /**
71 * Lambda metafactory implementation which dynamically creates an
72 * inner-class-like class per lambda callsite.
73 *
74 * @see LambdaMetafactory
75 */
76 /* package */ final class InnerClassLambdaMetafactory extends AbstractValidatingLambdaMetafactory {
77 private static final String LAMBDA_INSTANCE_FIELD = "LAMBDA_INSTANCE$";
78 private static final @Stable String[] ARG_NAME_CACHE = {"arg$1", "arg$2", "arg$3", "arg$4", "arg$5", "arg$6", "arg$7", "arg$8"};
79 private static final ClassDesc[] EMPTY_CLASSDESC_ARRAY = ConstantUtils.EMPTY_CLASSDESC;
80
81 // For dumping generated classes to disk, for debugging purposes
82 private static final ClassFileDumper lambdaProxyClassFileDumper;
83
84 private static final boolean disableEagerInitialization;
85
86 static {
87 // To dump the lambda proxy classes, set this system property:
88 // -Djdk.invoke.LambdaMetafactory.dumpProxyClassFiles
89 // or -Djdk.invoke.LambdaMetafactory.dumpProxyClassFiles=true
90 final String dumpProxyClassesKey = "jdk.invoke.LambdaMetafactory.dumpProxyClassFiles";
91 lambdaProxyClassFileDumper = ClassFileDumper.getInstance(dumpProxyClassesKey, "DUMP_LAMBDA_PROXY_CLASS_FILES");
92
93 final String disableEagerInitializationKey = "jdk.internal.lambda.disableEagerInitialization";
94 disableEagerInitialization = Boolean.getBoolean(disableEagerInitializationKey);
95 }
96
97 // See context values in AbstractValidatingLambdaMetafactory
98 private final ClassDesc implMethodClassDesc; // Name of type containing implementation "CC"
99 private final String implMethodName; // Name of implementation method "impl"
100 private final MethodTypeDesc implMethodDesc; // Type descriptor for implementation methods "(I)Ljava/lang/String;"
101 private final MethodType constructorType; // Generated class constructor type "(CC)void"
102 private final MethodTypeDesc constructorTypeDesc;// Type descriptor for the generated class constructor type "(CC)void"
103 private final ClassDesc[] argDescs; // Type descriptors for the constructor arguments
104 private final String lambdaClassName; // Generated name for the generated class "X$$Lambda$1"
105 private final ConstantPoolBuilder pool = ConstantPoolBuilder.of();
106 private final ClassEntry lambdaClassEntry; // Class entry for the generated class "X$$Lambda$1"
107 private final boolean useImplMethodHandle; // use MethodHandle invocation instead of symbolic bytecode invocation
108
109 /**
110 * General meta-factory constructor, supporting both standard cases and
111 * allowing for uncommon options such as serialization or bridging.
112 *
113 * @param caller Stacked automatically by VM; represents a lookup context
114 * with the accessibility privileges of the caller.
115 * @param factoryType Stacked automatically by VM; the signature of the
116 * invoked method, which includes the expected static
117 * type of the returned lambda object, and the static
118 * types of the captured arguments for the lambda. In
119 * the event that the implementation method is an
120 * instance method, the first argument in the invocation
121 * signature will correspond to the receiver.
122 * @param interfaceMethodName Name of the method in the functional interface to
123 * which the lambda or method reference is being
124 * converted, represented as a String.
125 * @param interfaceMethodType Type of the method in the functional interface to
126 * which the lambda or method reference is being
127 * converted, represented as a MethodType.
128 * @param implementation The implementation method which should be called (with
129 * suitable adaptation of argument types, return types,
130 * and adjustment for captured arguments) when methods of
131 * the resulting functional interface instance are invoked.
132 * @param dynamicMethodType The signature of the primary functional
133 * interface method after type variables are
134 * substituted with their instantiation from
135 * the capture site
136 * @param isSerializable Should the lambda be made serializable? If set,
137 * either the target type or one of the additional SAM
138 * types must extend {@code Serializable}.
139 * @param altInterfaces Additional interfaces which the lambda object
140 * should implement.
141 * @param altMethods Method types for additional signatures to be
142 * implemented by invoking the implementation method
143 * @throws LambdaConversionException If any of the meta-factory protocol
144 * invariants are violated
145 */
146 public InnerClassLambdaMetafactory(MethodHandles.Lookup caller,
147 MethodType factoryType,
148 String interfaceMethodName,
149 MethodType interfaceMethodType,
150 MethodHandle implementation,
151 MethodType dynamicMethodType,
152 boolean isSerializable,
153 Class<?>[] altInterfaces,
154 MethodType[] altMethods)
155 throws LambdaConversionException {
156 super(caller, factoryType, interfaceMethodName, interfaceMethodType,
157 implementation, dynamicMethodType,
158 isSerializable, altInterfaces, altMethods);
159 implMethodClassDesc = implClassDesc(implClass);
160 implMethodName = implInfo.getName();
161 implMethodDesc = methodDesc(implInfo.getMethodType());
162 constructorType = factoryType.changeReturnType(Void.TYPE);
163 lambdaClassName = lambdaClassName(targetClass);
164 lambdaClassEntry = pool.classEntry(ConstantUtils.internalNameToDesc(lambdaClassName));
165 // If the target class invokes a protected method inherited from a
166 // superclass in a different package, or does 'invokespecial', the
167 // lambda class has no access to the resolved method, or does
168 // 'invokestatic' on a hidden class which cannot be resolved by name.
169 // Instead, we need to pass the live implementation method handle to
170 // the proxy class to invoke directly. (javac prefers to avoid this
171 // situation by generating bridges in the target class)
172 useImplMethodHandle = (Modifier.isProtected(implInfo.getModifiers()) &&
173 !VerifyAccess.isSamePackage(targetClass, implInfo.getDeclaringClass())) ||
174 implKind == MethodHandleInfo.REF_invokeSpecial ||
175 implKind == MethodHandleInfo.REF_invokeStatic && implClass.isHidden();
176 int parameterCount = factoryType.parameterCount();
177 ClassDesc[] argDescs;
178 MethodTypeDesc constructorTypeDesc;
179 if (parameterCount > 0) {
180 argDescs = new ClassDesc[parameterCount];
181 for (int i = 0; i < parameterCount; i++) {
182 argDescs[i] = classDesc(factoryType.parameterType(i));
183 }
184 constructorTypeDesc = MethodTypeDescImpl.ofValidated(CD_void, argDescs);
185 } else {
186 argDescs = EMPTY_CLASSDESC_ARRAY;
187 constructorTypeDesc = MTD_void;
188 }
189 this.argDescs = argDescs;
190 this.constructorTypeDesc = constructorTypeDesc;
191 }
192
193 private static String argName(int i) {
194 return i < ARG_NAME_CACHE.length ? ARG_NAME_CACHE[i] : "arg$" + (i + 1);
195 }
196
197 private static String sanitizedTargetClassName(Class<?> targetClass) {
198 String name = targetClass.getName();
199 if (targetClass.isHidden()) {
200 // use the original class name
201 name = name.replace('/', '_');
202 }
203 return name.replace('.', '/');
204 }
205
206 private static String lambdaClassName(Class<?> targetClass) {
207 return sanitizedTargetClassName(targetClass).concat("$$Lambda");
208 }
209
210 /**
211 * Build the CallSite. Generate a class file which implements the functional
212 * interface, define the class, if there are no parameters create an instance
213 * of the class which the CallSite will return, otherwise, generate handles
214 * which will call the class' constructor.
215 *
216 * @return a CallSite, which, when invoked, will return an instance of the
217 * functional interface
218 * @throws LambdaConversionException If properly formed functional interface
219 * is not found
220 */
221 @Override
222 CallSite buildCallSite() throws LambdaConversionException {
223 final Class<?> innerClass = spinInnerClass();
224 if (factoryType.parameterCount() == 0 && disableEagerInitialization) {
225 try {
226 return new ConstantCallSite(caller.findStaticGetter(innerClass, LAMBDA_INSTANCE_FIELD,
227 factoryType.returnType()));
228 } catch (ReflectiveOperationException e) {
229 throw new LambdaConversionException(
230 "Exception finding " + LAMBDA_INSTANCE_FIELD + " static field", e);
231 }
232 } else {
233 try {
234 MethodHandle mh = caller.findConstructor(innerClass, constructorType);
235 if (factoryType.parameterCount() == 0) {
236 // In the case of a non-capturing lambda, we optimize linkage by pre-computing a single instance
237 Object inst = mh.invokeBasic();
238 return new ConstantCallSite(MethodHandles.constant(interfaceClass, inst));
239 } else {
240 return new ConstantCallSite(mh.asType(factoryType));
241 }
242 } catch (ReflectiveOperationException e) {
243 throw new LambdaConversionException("Exception finding constructor", e);
244 } catch (Throwable e) {
245 throw new LambdaConversionException("Exception instantiating lambda object", e);
246 }
247 }
248 }
249
250 /**
251 * Spins the lambda proxy class.
252 *
253 * This first checks if a lambda proxy class can be loaded from CDS archive.
254 * Otherwise, generate the lambda proxy class. If CDS dumping is enabled, it
255 * registers the lambda proxy class for including into the CDS archive.
256 */
257 private Class<?> spinInnerClass() throws LambdaConversionException {
258 // CDS does not handle disableEagerInitialization or useImplMethodHandle
259 if (!disableEagerInitialization && !useImplMethodHandle) {
260 if (CDS.isUsingArchive()) {
261 // load from CDS archive if present
262 Class<?> innerClass = LambdaProxyClassArchive.find(targetClass,
263 interfaceMethodName,
264 factoryType,
265 interfaceMethodType,
266 implementation,
267 dynamicMethodType,
268 isSerializable,
269 altInterfaces,
270 altMethods);
271 if (innerClass != null) return innerClass;
272 }
273
274 // include lambda proxy class in CDS archive at dump time
275 if (CDS.isDumpingArchive()) {
276 Class<?> innerClass = generateInnerClass();
277 LambdaProxyClassArchive.register(targetClass,
278 interfaceMethodName,
279 factoryType,
280 interfaceMethodType,
281 implementation,
282 dynamicMethodType,
283 isSerializable,
284 altInterfaces,
285 altMethods,
286 innerClass);
287 return innerClass;
288 }
289
290 }
291 return generateInnerClass();
292 }
293
294 /**
295 * Generate a class file which implements the functional
296 * interface, define and return the class.
297 *
298 * @return a Class which implements the functional interface
299 * @throws LambdaConversionException If properly formed functional interface
300 * is not found
301 */
302 private Class<?> generateInnerClass() throws LambdaConversionException {
303 List<ClassDesc> interfaces;
304 ClassDesc interfaceDesc = classDesc(interfaceClass);
305 boolean accidentallySerializable = !isSerializable && Serializable.class.isAssignableFrom(interfaceClass);
306 if (altInterfaces.length == 0) {
307 interfaces = List.of(interfaceDesc);
308 } else {
309 // Assure no duplicate interfaces (ClassFormatError)
310 Set<ClassDesc> itfs = LinkedHashSet.newLinkedHashSet(altInterfaces.length + 1);
311 itfs.add(interfaceDesc);
312 for (Class<?> i : altInterfaces) {
313 itfs.add(classDesc(i));
314 accidentallySerializable |= !isSerializable && Serializable.class.isAssignableFrom(i);
315 }
316 interfaces = List.copyOf(itfs);
317 }
318 final boolean finalAccidentallySerializable = accidentallySerializable;
319 final byte[] classBytes = ClassFile.of().build(lambdaClassEntry, pool, new Consumer<ClassBuilder>() {
320 @Override
321 public void accept(ClassBuilder clb) {
322 clb.withVersion(ClassFileFormatVersion.latest().major(), (PreviewFeatures.isEnabled() ? 0xFFFF0000 : 0))
323 .withFlags(ACC_SUPER | ACC_FINAL | ACC_SYNTHETIC)
324 .withInterfaceSymbols(interfaces);
325
326 // generate LoadableDescriptors attribute if it references any value class
327 if (PreviewFeatures.isEnabled()) {
328 generateLoadableDescriptors(clb);
329 }
330
331 // Generate final fields to be filled in by constructor
332 for (int i = 0; i < argDescs.length; i++) {
333 clb.withField(argName(i), argDescs[i], ACC_PRIVATE | ACC_FINAL);
334 }
335
336 generateConstructor(clb);
337
338 if (factoryType.parameterCount() == 0 && disableEagerInitialization) {
339 generateClassInitializer(clb);
340 }
341
342 // Forward the SAM method
343 clb.withMethodBody(interfaceMethodName,
344 methodDesc(interfaceMethodType),
345 ACC_PUBLIC,
346 forwardingMethod(interfaceMethodType));
347
348 // Forward the bridges
349 if (altMethods != null) {
350 for (MethodType mt : altMethods) {
351 clb.withMethodBody(interfaceMethodName,
352 methodDesc(mt),
353 ACC_PUBLIC | ACC_BRIDGE,
354 forwardingMethod(mt));
355 }
356 }
357
358 if (isSerializable)
359 generateSerializationFriendlyMethods(clb);
360 else if (finalAccidentallySerializable)
361 generateSerializationHostileMethods(clb);
362 }
363 });
364
365 // Define the generated class in this VM.
366
367 try {
368 // this class is linked at the indy callsite; so define a hidden nestmate
369 var classdata = useImplMethodHandle? implementation : null;
370 return caller.makeHiddenClassDefiner(lambdaClassName, classBytes, lambdaProxyClassFileDumper, NESTMATE_CLASS | STRONG_LOADER_LINK)
371 .defineClass(!disableEagerInitialization, classdata);
372
373 } catch (Throwable t) {
374 throw new InternalError(t);
375 }
376 }
377
378 /**
379 * Generate a static field and a static initializer that sets this field to an instance of the lambda
380 */
381 private void generateClassInitializer(ClassBuilder clb) {
382 ClassDesc lambdaTypeDescriptor = classDesc(factoryType.returnType());
383
384 // Generate the static final field that holds the lambda singleton
385 clb.withField(LAMBDA_INSTANCE_FIELD, lambdaTypeDescriptor, ACC_PRIVATE | ACC_STATIC | ACC_FINAL);
386
387 // Instantiate the lambda and store it to the static final field
388 clb.withMethodBody(CLASS_INIT_NAME, MTD_void, ACC_STATIC, new Consumer<>() {
389 @Override
390 public void accept(CodeBuilder cob) {
391 assert factoryType.parameterCount() == 0;
392 cob.new_(lambdaClassEntry)
393 .dup()
394 .invokespecial(pool.methodRefEntry(lambdaClassEntry, pool.nameAndTypeEntry(INIT_NAME, constructorTypeDesc)))
395 .putstatic(pool.fieldRefEntry(lambdaClassEntry, pool.nameAndTypeEntry(LAMBDA_INSTANCE_FIELD, lambdaTypeDescriptor)))
396 .return_();
397 }
398 });
399 }
400
401 /**
402 * Generate the constructor for the class
403 */
404 private void generateConstructor(ClassBuilder clb) {
405 // Generate constructor
406 clb.withMethodBody(INIT_NAME, constructorTypeDesc, ACC_PRIVATE,
407 new Consumer<>() {
408 @Override
409 public void accept(CodeBuilder cob) {
410 cob.aload(0)
411 .invokespecial(CD_Object, INIT_NAME, MTD_void);
412 int parameterCount = factoryType.parameterCount();
413 for (int i = 0; i < parameterCount; i++) {
414 cob.aload(0)
415 .loadLocal(TypeKind.from(factoryType.parameterType(i)), cob.parameterSlot(i))
416 .putfield(pool.fieldRefEntry(lambdaClassEntry, pool.nameAndTypeEntry(argName(i), argDescs[i])));
417 }
418 cob.return_();
419 }
420 });
421 }
422
423 private static class SerializationSupport {
424 // Serialization support
425 private static final ClassDesc CD_SerializedLambda = ClassOrInterfaceDescImpl.ofValidated("Ljava/lang/invoke/SerializedLambda;");
426 private static final ClassDesc CD_ObjectOutputStream = ClassOrInterfaceDescImpl.ofValidated("Ljava/io/ObjectOutputStream;");
427 private static final ClassDesc CD_ObjectInputStream = ClassOrInterfaceDescImpl.ofValidated("Ljava/io/ObjectInputStream;");
428 private static final MethodTypeDesc MTD_Object = MethodTypeDescImpl.ofValidated(CD_Object);
429 private static final MethodTypeDesc MTD_void_ObjectOutputStream = MethodTypeDescImpl.ofValidated(CD_void, CD_ObjectOutputStream);
430 private static final MethodTypeDesc MTD_void_ObjectInputStream = MethodTypeDescImpl.ofValidated(CD_void, CD_ObjectInputStream);
431
432 private static final String NAME_METHOD_WRITE_REPLACE = "writeReplace";
433 private static final String NAME_METHOD_READ_OBJECT = "readObject";
434 private static final String NAME_METHOD_WRITE_OBJECT = "writeObject";
435
436 static final ClassDesc CD_NotSerializableException = ClassOrInterfaceDescImpl.ofValidated("Ljava/io/NotSerializableException;");
437 static final MethodTypeDesc MTD_CTOR_NOT_SERIALIZABLE_EXCEPTION = MethodTypeDescImpl.ofValidated(CD_void, CD_String);
438 static final MethodTypeDesc MTD_CTOR_SERIALIZED_LAMBDA = MethodTypeDescImpl.ofValidated(CD_void,
439 CD_Class, CD_String, CD_String, CD_String, CD_int, CD_String, CD_String, CD_String, CD_String, ConstantUtils.CD_Object_array);
440
441 }
442
443 /**
444 * Generate a writeReplace method that supports serialization
445 */
446 private void generateSerializationFriendlyMethods(ClassBuilder clb) {
447 clb.withMethodBody(SerializationSupport.NAME_METHOD_WRITE_REPLACE, SerializationSupport.MTD_Object, ACC_PRIVATE | ACC_FINAL,
448 new Consumer<>() {
449 @Override
450 public void accept(CodeBuilder cob) {
451 cob.new_(SerializationSupport.CD_SerializedLambda)
452 .dup()
453 .ldc(ClassDesc.ofInternalName(sanitizedTargetClassName(targetClass)))
454 .ldc(factoryType.returnType().getName().replace('.', '/'))
455 .ldc(interfaceMethodName)
456 .ldc(interfaceMethodType.toMethodDescriptorString())
457 .ldc(implInfo.getReferenceKind())
458 .ldc(implInfo.getDeclaringClass().getName().replace('.', '/'))
459 .ldc(implInfo.getName())
460 .ldc(implInfo.getMethodType().toMethodDescriptorString())
461 .ldc(dynamicMethodType.toMethodDescriptorString())
462 .loadConstant(argDescs.length)
463 .anewarray(CD_Object);
464 for (int i = 0; i < argDescs.length; i++) {
465 cob.dup()
466 .loadConstant(i)
467 .aload(0)
468 .getfield(pool.fieldRefEntry(lambdaClassEntry, pool.nameAndTypeEntry(argName(i), argDescs[i])));
469 TypeConvertingMethodAdapter.boxIfTypePrimitive(cob, TypeKind.from(argDescs[i]));
470 cob.aastore();
471 }
472 cob.invokespecial(SerializationSupport.CD_SerializedLambda, INIT_NAME,
473 SerializationSupport.MTD_CTOR_SERIALIZED_LAMBDA)
474 .areturn();
475 }
476 });
477 }
478
479 /**
480 * Generate a readObject/writeObject method that is hostile to serialization
481 */
482 private void generateSerializationHostileMethods(ClassBuilder clb) {
483 var hostileMethod = new Consumer<MethodBuilder>() {
484 @Override
485 public void accept(MethodBuilder mb) {
486 ConstantPoolBuilder cp = mb.constantPool();
487 ClassEntry nseCE = cp.classEntry(SerializationSupport.CD_NotSerializableException);
488 mb.with(ExceptionsAttribute.of(nseCE))
489 .withCode(new Consumer<CodeBuilder>() {
490 @Override
491 public void accept(CodeBuilder cob) {
492 cob.new_(nseCE)
493 .dup()
494 .ldc("Non-serializable lambda")
495 .invokespecial(cp.methodRefEntry(nseCE, cp.nameAndTypeEntry(INIT_NAME,
496 SerializationSupport.MTD_CTOR_NOT_SERIALIZABLE_EXCEPTION)))
497 .athrow();
498 }
499 });
500 }
501 };
502 clb.withMethod(SerializationSupport.NAME_METHOD_WRITE_OBJECT, SerializationSupport.MTD_void_ObjectOutputStream,
503 ACC_PRIVATE + ACC_FINAL, hostileMethod);
504 clb.withMethod(SerializationSupport.NAME_METHOD_READ_OBJECT, SerializationSupport.MTD_void_ObjectInputStream,
505 ACC_PRIVATE + ACC_FINAL, hostileMethod);
506 }
507
508 /**
509 * This method generates a method body which calls the lambda implementation
510 * method, converting arguments, as needed.
511 */
512 Consumer<CodeBuilder> forwardingMethod(MethodType methodType) {
513 return new Consumer<>() {
514 @Override
515 public void accept(CodeBuilder cob) {
516 if (implKind == MethodHandleInfo.REF_newInvokeSpecial) {
517 cob.new_(implMethodClassDesc)
518 .dup();
519 }
520 if (useImplMethodHandle) {
521 ConstantPoolBuilder cp = cob.constantPool();
522 cob.ldc(cp.constantDynamicEntry(cp.bsmEntry(cp.methodHandleEntry(BSM_CLASS_DATA), List.of()),
523 cp.nameAndTypeEntry(DEFAULT_NAME, CD_MethodHandle)));
524 }
525 for (int i = 0; i < argDescs.length; i++) {
526 cob.aload(0)
527 .getfield(pool.fieldRefEntry(lambdaClassEntry, pool.nameAndTypeEntry(argName(i), argDescs[i])));
528 }
529
530 convertArgumentTypes(cob, methodType);
531
532 if (useImplMethodHandle) {
533 MethodType mtype = implInfo.getMethodType();
534 if (implKind != MethodHandleInfo.REF_invokeStatic) {
535 mtype = mtype.insertParameterTypes(0, implClass);
536 }
537 cob.invokevirtual(CD_MethodHandle, "invokeExact", methodDesc(mtype));
538 } else {
539 // Invoke the method we want to forward to
540 cob.invoke(invocationOpcode(), implMethodClassDesc, implMethodName, implMethodDesc, implClass.isInterface());
541 }
542 // Convert the return value (if any) and return it
543 // Note: if adapting from non-void to void, the 'return'
544 // instruction will pop the unneeded result
545 Class<?> implReturnClass = implMethodType.returnType();
546 Class<?> samReturnClass = methodType.returnType();
547 TypeConvertingMethodAdapter.convertType(cob, implReturnClass, samReturnClass, samReturnClass);
548 cob.return_(TypeKind.from(samReturnClass));
549 }
550 };
551 }
552
553 private void convertArgumentTypes(CodeBuilder cob, MethodType samType) {
554 int samParametersLength = samType.parameterCount();
555 int captureArity = factoryType.parameterCount();
556 for (int i = 0; i < samParametersLength; i++) {
557 Class<?> argType = samType.parameterType(i);
558 cob.loadLocal(TypeKind.from(argType), cob.parameterSlot(i));
559 TypeConvertingMethodAdapter.convertType(cob, argType, implMethodType.parameterType(captureArity + i), dynamicMethodType.parameterType(i));
560 }
561 }
562
563 /*
564 * LoadableDescriptors attribute builder
565 */
566 static class LoadableDescriptorsAttributeBuilder {
567 private final Set<String> loadableDescriptors = new HashSet<>();
568 LoadableDescriptorsAttributeBuilder(Class<?> targetClass) {
569 if (requiresLoadableDescriptors(targetClass)) {
570 loadableDescriptors.add(targetClass.descriptorString());
571 }
572 }
573
574 /*
575 * Add the value types referenced in the given MethodType.
576 */
577 LoadableDescriptorsAttributeBuilder add(MethodType mt) {
578 // parameter types
579 for (Class<?> paramType : mt.ptypes()) {
580 if (requiresLoadableDescriptors(paramType)) {
581 loadableDescriptors.add(paramType.descriptorString());
582 }
583 }
584 // return type
585 if (requiresLoadableDescriptors(mt.returnType())) {
586 loadableDescriptors.add(mt.returnType().descriptorString());
587 }
588 return this;
589 }
590
591 LoadableDescriptorsAttributeBuilder add(MethodType... mtypes) {
592 for (MethodType mt : mtypes) {
593 add(mt);
594 }
595 return this;
596 }
597
598 boolean requiresLoadableDescriptors(Class<?> cls) {
599 return cls.isValue() && cls.accessFlags().contains(AccessFlag.FINAL);
600 }
601
602 boolean isEmpty() {
603 return loadableDescriptors.isEmpty();
604 }
605
606 void build(ClassBuilder clb) {
607 if (!isEmpty()) {
608 List<Utf8Entry> lds = new ArrayList<Utf8Entry>(loadableDescriptors.size());
609 for (String ld : loadableDescriptors) {
610 lds.add(clb.constantPool().utf8Entry(ld));
611 }
612 clb.with(LoadableDescriptorsAttribute.of(lds));
613 }
614 }
615 }
616
617 /**
618 * Generate LoadableDescriptors attribute if it references any value class
619 */
620 private void generateLoadableDescriptors(ClassBuilder clb) {
621 LoadableDescriptorsAttributeBuilder builder = new LoadableDescriptorsAttributeBuilder(targetClass);
622 builder.add(factoryType)
623 .add(interfaceMethodType)
624 .add(implMethodType)
625 .add(dynamicMethodType)
626 .add(altMethods)
627 .build(clb);
628 }
629
630 private Opcode invocationOpcode() throws InternalError {
631 return switch (implKind) {
632 case MethodHandleInfo.REF_invokeStatic -> Opcode.INVOKESTATIC;
633 case MethodHandleInfo.REF_newInvokeSpecial -> Opcode.INVOKESPECIAL;
634 case MethodHandleInfo.REF_invokeVirtual -> Opcode.INVOKEVIRTUAL;
635 case MethodHandleInfo.REF_invokeInterface -> Opcode.INVOKEINTERFACE;
636 case MethodHandleInfo.REF_invokeSpecial -> Opcode.INVOKESPECIAL;
637 default -> throw new InternalError("Unexpected invocation kind: " + implKind);
638 };
639 }
640
641 static ClassDesc implClassDesc(Class<?> cls) {
642 return cls.isHidden() ? null : ConstantUtils.referenceClassDesc(cls.descriptorString());
643 }
644
645 static ClassDesc classDesc(Class<?> cls) {
646 return cls.isPrimitive() ? Wrapper.forPrimitiveType(cls).basicClassDescriptor()
647 : ConstantUtils.referenceClassDesc(cls.descriptorString());
648 }
649
650 static MethodTypeDesc methodDesc(MethodType mt) {
651 var params = new ClassDesc[mt.parameterCount()];
652 for (int i = 0; i < params.length; i++) {
653 params[i] = classDesc(mt.parameterType(i));
654 }
655 return MethodTypeDescImpl.ofValidated(classDesc(mt.returnType()), params);
656 }
657 }