1 /*
2 * Copyright (c) 2012, 2026, 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.CDS;
30 import jdk.internal.util.ClassFileDumper;
31 import sun.invoke.util.VerifyAccess;
32
33 import java.io.Serializable;
34 import java.lang.classfile.ClassBuilder;
35 import java.lang.classfile.ClassFile;
36 import java.lang.classfile.CodeBuilder;
37 import java.lang.classfile.MethodBuilder;
38 import java.lang.classfile.Opcode;
39 import java.lang.classfile.TypeKind;
40 import java.lang.constant.ClassDesc;
41 import java.lang.constant.MethodTypeDesc;
42 import java.lang.reflect.Modifier;
43 import java.util.LinkedHashSet;
44 import java.util.List;
45 import java.util.Set;
46 import java.util.function.Consumer;
47 import java.util.function.Function;
48
49 import static java.lang.classfile.ClassFile.*;
50 import java.lang.classfile.attribute.ExceptionsAttribute;
51 import java.lang.classfile.constantpool.ClassEntry;
52 import java.lang.classfile.constantpool.ConstantPoolBuilder;
53
54 import static java.lang.constant.ConstantDescs.*;
55 import static java.lang.invoke.MethodHandleNatives.Constants.NESTMATE_CLASS;
56 import static java.lang.invoke.MethodHandleNatives.Constants.STRONG_LOADER_LINK;
57 import java.util.ArrayList;
58 import jdk.internal.constant.ConstantUtils;
59 import jdk.internal.constant.MethodTypeDescImpl;
60 import jdk.internal.vm.annotation.Stable;
61 import sun.invoke.util.Wrapper;
62
63 /**
64 * Lambda metafactory implementation which dynamically creates an
65 * inner-class-like class per lambda callsite.
66 *
67 * @see LambdaMetafactory
68 */
69 /* package */ final class InnerClassLambdaMetafactory extends AbstractValidatingLambdaMetafactory {
70 private static final String LAMBDA_INSTANCE_FIELD = "LAMBDA_INSTANCE$";
71 private static final @Stable String[] ARG_NAME_CACHE = {"arg$1", "arg$2", "arg$3", "arg$4", "arg$5", "arg$6", "arg$7", "arg$8"};
72 private static final ClassDesc[] EMPTY_CLASSDESC_ARRAY = ConstantUtils.EMPTY_CLASSDESC;
73
74 // For dumping generated classes to disk, for debugging purposes
75 private static final ClassFileDumper lambdaProxyClassFileDumper;
76
77 private static final boolean disableEagerInitialization;
78
79 static {
80 // To dump the lambda proxy classes, set this system property:
81 // -Djdk.invoke.LambdaMetafactory.dumpProxyClassFiles
82 // or -Djdk.invoke.LambdaMetafactory.dumpProxyClassFiles=true
83 final String dumpProxyClassesKey = "jdk.invoke.LambdaMetafactory.dumpProxyClassFiles";
84 lambdaProxyClassFileDumper = ClassFileDumper.getInstance(dumpProxyClassesKey, "DUMP_LAMBDA_PROXY_CLASS_FILES");
85
86 final String disableEagerInitializationKey = "jdk.internal.lambda.disableEagerInitialization";
87 disableEagerInitialization = Boolean.getBoolean(disableEagerInitializationKey);
88 }
89
90 // See context values in AbstractValidatingLambdaMetafactory
91 private final ClassDesc implMethodClassDesc; // Name of type containing implementation "CC"
92 private final String implMethodName; // Name of implementation method "impl"
93 private final MethodTypeDesc implMethodDesc; // Type descriptor for implementation methods "(I)Ljava/lang/String;"
94 private final MethodType constructorType; // Generated class constructor type "(CC)void"
95 private final MethodTypeDesc constructorTypeDesc;// Type descriptor for the generated class constructor type "(CC)void"
96 private final ClassDesc[] argDescs; // Type descriptors for the constructor arguments
97 private final String lambdaClassName; // Generated name for the generated class "X$$Lambda$1"
98 private final ConstantPoolBuilder pool = ConstantPoolBuilder.of();
99 private final ClassEntry lambdaClassEntry; // Class entry for the generated class "X$$Lambda$1"
100 private final boolean useImplMethodHandle; // use MethodHandle invocation instead of symbolic bytecode invocation
101
102 /**
103 * General meta-factory constructor, supporting both standard cases and
104 * allowing for uncommon options such as serialization or bridging.
105 *
106 * @param caller Stacked automatically by VM; represents a lookup context
107 * with the accessibility privileges of the caller.
108 * @param factoryType Stacked automatically by VM; the signature of the
109 * invoked method, which includes the expected static
110 * type of the returned lambda object, and the static
111 * types of the captured arguments for the lambda. In
112 * the event that the implementation method is an
113 * instance method, the first argument in the invocation
114 * signature will correspond to the receiver.
115 * @param interfaceMethodName Name of the method in the functional interface to
116 * which the lambda or method reference is being
117 * converted, represented as a String.
118 * @param interfaceMethodType Type of the method in the functional interface to
119 * which the lambda or method reference is being
120 * converted, represented as a MethodType.
121 * @param implementation The implementation method which should be called (with
122 * suitable adaptation of argument types, return types,
123 * and adjustment for captured arguments) when methods of
124 * the resulting functional interface instance are invoked.
125 * @param dynamicMethodType The signature of the primary functional
126 * interface method after type variables are
127 * substituted with their instantiation from
128 * the capture site
129 * @param isSerializable Should the lambda be made serializable? If set,
130 * either the target type or one of the additional SAM
131 * types must extend {@code Serializable}.
132 * @param altInterfaces Additional interfaces which the lambda object
133 * should implement.
134 * @param altMethods Method types for additional signatures to be
135 * implemented by invoking the implementation method
136 * @param finisher Function called at the end of the lambda class build process
137 * that returns an additional object to append to the class data,
138 * may be (@code null}, may return {@code null}.
139 * @throws LambdaConversionException If any of the meta-factory protocol
140 * invariants are violated
141 */
142 public InnerClassLambdaMetafactory(MethodHandles.Lookup caller,
143 MethodType factoryType,
144 String interfaceMethodName,
145 MethodType interfaceMethodType,
146 MethodHandle implementation,
147 MethodType dynamicMethodType,
148 boolean isSerializable,
149 Class<?>[] altInterfaces,
150 MethodType[] altMethods,
151 Function<ClassBuilder, Object> finisher)
152 throws LambdaConversionException {
153 super(caller, factoryType, interfaceMethodName, interfaceMethodType,
154 implementation, dynamicMethodType,
155 isSerializable, altInterfaces, altMethods, finisher);
156 implMethodClassDesc = implClassDesc(implClass);
157 implMethodName = implInfo.getName();
158 implMethodDesc = methodDesc(implInfo.getMethodType());
159 constructorType = factoryType.changeReturnType(Void.TYPE);
160 lambdaClassName = lambdaClassName(targetClass);
161 lambdaClassEntry = pool.classEntry(ConstantUtils.internalNameToDesc(lambdaClassName));
162 // If the target class invokes a protected method inherited from a
163 // superclass in a different package, or does 'invokespecial', the
164 // lambda class has no access to the resolved method, or does
165 // 'invokestatic' on a hidden class which cannot be resolved by name.
166 // Instead, we need to pass the live implementation method handle to
167 // the proxy class to invoke directly. (javac prefers to avoid this
168 // situation by generating bridges in the target class)
169 useImplMethodHandle = (Modifier.isProtected(implInfo.getModifiers()) &&
170 !VerifyAccess.isSamePackage(targetClass, implInfo.getDeclaringClass())) ||
171 implKind == MethodHandleInfo.REF_invokeSpecial ||
172 implKind == MethodHandleInfo.REF_invokeStatic && implClass.isHidden();
173 int parameterCount = factoryType.parameterCount();
174 ClassDesc[] argDescs;
175 MethodTypeDesc constructorTypeDesc;
176 if (parameterCount > 0) {
177 argDescs = new ClassDesc[parameterCount];
178 for (int i = 0; i < parameterCount; i++) {
179 argDescs[i] = classDesc(factoryType.parameterType(i));
180 }
181 constructorTypeDesc = MethodTypeDescImpl.ofValidated(CD_void, argDescs);
182 } else {
183 argDescs = EMPTY_CLASSDESC_ARRAY;
184 constructorTypeDesc = MTD_void;
185 }
186 this.argDescs = argDescs;
187 this.constructorTypeDesc = constructorTypeDesc;
188 }
189
190 private static String argName(int i) {
191 return i < ARG_NAME_CACHE.length ? ARG_NAME_CACHE[i] : "arg$" + (i + 1);
192 }
193
194 private static String sanitizedTargetClassName(Class<?> targetClass) {
195 String name = targetClass.getName();
196 if (targetClass.isHidden()) {
197 // use the original class name
198 name = name.replace('/', '_');
199 }
200 return name.replace('.', '/');
201 }
202
203 private static String lambdaClassName(Class<?> targetClass) {
204 return sanitizedTargetClassName(targetClass).concat("$$Lambda");
205 }
206
207 /**
208 * Build the CallSite. Generate a class file which implements the functional
209 * interface, define the class, if there are no parameters create an instance
210 * of the class which the CallSite will return, otherwise, generate handles
211 * which will call the class' constructor.
212 *
213 * @return a CallSite, which, when invoked, will return an instance of the
214 * functional interface
215 * @throws LambdaConversionException If properly formed functional interface
216 * is not found
217 */
218 @Override
219 CallSite buildCallSite() throws LambdaConversionException {
220 final Class<?> innerClass = spinInnerClass();
221 if (factoryType.parameterCount() == 0 && disableEagerInitialization) {
222 try {
223 return new ConstantCallSite(caller.findStaticGetter(innerClass, LAMBDA_INSTANCE_FIELD,
224 factoryType.returnType()));
225 } catch (ReflectiveOperationException e) {
226 throw new LambdaConversionException(
227 "Exception finding " + LAMBDA_INSTANCE_FIELD + " static field", e);
228 }
229 } else {
230 try {
231 MethodHandle mh = caller.findConstructor(innerClass, constructorType);
232 if (factoryType.parameterCount() == 0) {
233 // In the case of a non-capturing lambda, we optimize linkage by pre-computing a single instance
234 Object inst = mh.invokeBasic();
235 return new ConstantCallSite(MethodHandles.constant(interfaceClass, inst));
236 } else {
237 return new ConstantCallSite(mh.asType(factoryType));
238 }
239 } catch (ReflectiveOperationException e) {
240 throw new LambdaConversionException("Exception finding constructor", e);
241 } catch (Throwable e) {
242 throw new LambdaConversionException("Exception instantiating lambda object", e);
243 }
244 }
245 }
246
247 /**
248 * Spins the lambda proxy class.
249 *
250 * This first checks if a lambda proxy class can be loaded from CDS archive.
251 * Otherwise, generate the lambda proxy class. If CDS dumping is enabled, it
252 * registers the lambda proxy class for including into the CDS archive.
253 */
254 private Class<?> spinInnerClass() throws LambdaConversionException {
255 // CDS does not handle disableEagerInitialization or useImplMethodHandle
256 if (!disableEagerInitialization && !useImplMethodHandle) {
257 if (CDS.isUsingArchive()) {
258 // load from CDS archive if present
259 Class<?> innerClass = LambdaProxyClassArchive.find(targetClass,
260 interfaceMethodName,
261 factoryType,
262 interfaceMethodType,
263 implementation,
264 dynamicMethodType,
265 isSerializable,
266 altInterfaces,
267 altMethods);
268 if (innerClass != null) return innerClass;
269 }
270
271 // include lambda proxy class in CDS archive at dump time
272 if (CDS.isDumpingArchive()) {
273 Class<?> innerClass = generateInnerClass();
274 LambdaProxyClassArchive.register(targetClass,
275 interfaceMethodName,
276 factoryType,
277 interfaceMethodType,
278 implementation,
279 dynamicMethodType,
280 isSerializable,
281 altInterfaces,
282 altMethods,
283 innerClass);
284 return innerClass;
285 }
286
287 }
288 return generateInnerClass();
289 }
290
291 /**
292 * Generate a class file which implements the functional
293 * interface, define and return the class.
294 *
295 * @return a Class which implements the functional interface
296 * @throws LambdaConversionException If properly formed functional interface
297 * is not found
298 */
299 private Class<?> generateInnerClass() throws LambdaConversionException {
300 List<ClassDesc> interfaces;
301 ClassDesc interfaceDesc = classDesc(interfaceClass);
302 boolean accidentallySerializable = !isSerializable && Serializable.class.isAssignableFrom(interfaceClass);
303 if (altInterfaces.length == 0) {
304 interfaces = List.of(interfaceDesc);
305 } else {
306 // Assure no duplicate interfaces (ClassFormatError)
307 Set<ClassDesc> itfs = LinkedHashSet.newLinkedHashSet(altInterfaces.length + 1);
308 itfs.add(interfaceDesc);
309 for (Class<?> i : altInterfaces) {
310 itfs.add(classDesc(i));
311 accidentallySerializable |= !isSerializable && Serializable.class.isAssignableFrom(i);
312 }
313 interfaces = List.copyOf(itfs);
314 }
315 final boolean finalAccidentallySerializable = accidentallySerializable;
316 final Object[] additionalClassDataHolder = new Object[1];
317 final byte[] classBytes = ClassFile.of().build(lambdaClassEntry, pool, new Consumer<ClassBuilder>() {
318 @Override
319 public void accept(ClassBuilder clb) {
320 clb.withFlags(ACC_SUPER | ACC_FINAL | ACC_SYNTHETIC)
321 .withInterfaceSymbols(interfaces);
322 // All Classes in the BSM argument method types are loaded; no need for LoadableDescriptors
323
324 // Generate final fields to be filled in by constructor
325 for (int i = 0; i < argDescs.length; i++) {
326 clb.withField(argName(i), argDescs[i], ACC_PRIVATE | ACC_FINAL);
327 }
328
329 generateConstructor(clb);
330
331 if (factoryType.parameterCount() == 0 && disableEagerInitialization) {
332 generateClassInitializer(clb);
333 }
334
335 // Forward the SAM method
336 clb.withMethodBody(interfaceMethodName,
337 methodDesc(interfaceMethodType),
338 ACC_PUBLIC,
339 forwardingMethod(interfaceMethodType));
340
341 // Forward the bridges
342 if (altMethods != null) {
343 for (MethodType mt : altMethods) {
344 clb.withMethodBody(interfaceMethodName,
345 methodDesc(mt),
346 ACC_PUBLIC | ACC_BRIDGE,
347 forwardingMethod(mt));
348 }
349 }
350
351 if (isSerializable)
352 generateSerializationFriendlyMethods(clb);
353 else if (finalAccidentallySerializable)
354 generateSerializationHostileMethods(clb);
355
356 if (finisher != null) {
357 additionalClassDataHolder[0] = finisher.apply(clb);
358 }
359 }
360 });
361
362 // Define the generated class in this VM.
363
364 try {
365 // this class is linked at the indy callsite; so define a hidden nestmate
366 var additionalClassData = additionalClassDataHolder[0];
367 var classdata = additionalClassData == null
368 ? useImplMethodHandle ? List.of(implementation) : null
369 : useImplMethodHandle ? List.of(implementation, additionalClassData) : List.of(additionalClassData);
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 int parameterCount = factoryType.parameterCount();
411 for (int i = 0; i < parameterCount; i++) {
412 cob.aload(0)
413 .loadLocal(TypeKind.from(factoryType.parameterType(i)), cob.parameterSlot(i))
414 .putfield(pool.fieldRefEntry(lambdaClassEntry, pool.nameAndTypeEntry(argName(i), argDescs[i])));
415 }
416 cob.aload(0)
417 .invokespecial(CD_Object, INIT_NAME, MTD_void)
418 .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_AT), List.of(cp.intEntry(0))),
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 private Opcode invocationOpcode() throws InternalError {
564 return switch (implKind) {
565 case MethodHandleInfo.REF_invokeStatic -> Opcode.INVOKESTATIC;
566 case MethodHandleInfo.REF_newInvokeSpecial -> Opcode.INVOKESPECIAL;
567 case MethodHandleInfo.REF_invokeVirtual -> Opcode.INVOKEVIRTUAL;
568 case MethodHandleInfo.REF_invokeInterface -> Opcode.INVOKEINTERFACE;
569 case MethodHandleInfo.REF_invokeSpecial -> Opcode.INVOKESPECIAL;
570 default -> throw new InternalError("Unexpected invocation kind: " + implKind);
571 };
572 }
573
574 static ClassDesc implClassDesc(Class<?> cls) {
575 return cls.isHidden() ? null : ConstantUtils.referenceClassDesc(cls.descriptorString());
576 }
577
578 static ClassDesc classDesc(Class<?> cls) {
579 return cls.isPrimitive() ? Wrapper.forPrimitiveType(cls).basicClassDescriptor()
580 : ConstantUtils.referenceClassDesc(cls.descriptorString());
581 }
582
583 static MethodTypeDesc methodDesc(MethodType mt) {
584 var params = new ClassDesc[mt.parameterCount()];
585 for (int i = 0; i < params.length; i++) {
586 params[i] = classDesc(mt.parameterType(i));
587 }
588 return MethodTypeDescImpl.ofValidated(classDesc(mt.returnType()), params);
589 }
590 }