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.misc.CDS;
29 import jdk.internal.org.objectweb.asm.*;
30 import jdk.internal.util.ClassFileDumper;
31 import sun.invoke.util.BytecodeDescriptor;
32 import sun.invoke.util.VerifyAccess;
33 import sun.security.action.GetBooleanAction;
34
35 import java.io.Serializable;
36 import java.lang.constant.ConstantDescs;
37 import java.lang.reflect.Modifier;
38 import java.util.LinkedHashSet;
39 import java.util.Set;
40
41 import static java.lang.invoke.MethodHandleStatics.CLASSFILE_VERSION;
42 import static java.lang.invoke.MethodHandles.Lookup.ClassOption.NESTMATE;
43 import static java.lang.invoke.MethodHandles.Lookup.ClassOption.STRONG;
44 import static java.lang.invoke.MethodType.methodType;
45 import static jdk.internal.org.objectweb.asm.Opcodes.*;
46
47 /**
48 * Lambda metafactory implementation which dynamically creates an
49 * inner-class-like class per lambda callsite.
50 *
51 * @see LambdaMetafactory
52 */
53 /* package */ final class InnerClassLambdaMetafactory extends AbstractValidatingLambdaMetafactory {
54 private static final String METHOD_DESCRIPTOR_VOID = Type.getMethodDescriptor(Type.VOID_TYPE);
55 private static final String JAVA_LANG_OBJECT = "java/lang/Object";
56 private static final String NAME_CTOR = "<init>";
57 private static final String LAMBDA_INSTANCE_FIELD = "LAMBDA_INSTANCE$";
58
59 //Serialization support
60 private static final String NAME_SERIALIZED_LAMBDA = "java/lang/invoke/SerializedLambda";
61 private static final String NAME_NOT_SERIALIZABLE_EXCEPTION = "java/io/NotSerializableException";
62 private static final String DESCR_METHOD_WRITE_REPLACE = "()Ljava/lang/Object;";
63 private static final String DESCR_METHOD_WRITE_OBJECT = "(Ljava/io/ObjectOutputStream;)V";
64 private static final String DESCR_METHOD_READ_OBJECT = "(Ljava/io/ObjectInputStream;)V";
65
66 private static final String NAME_METHOD_WRITE_REPLACE = "writeReplace";
67 private static final String NAME_METHOD_READ_OBJECT = "readObject";
68 private static final String NAME_METHOD_WRITE_OBJECT = "writeObject";
69
70 private static final String DESCR_CLASS = "Ljava/lang/Class;";
71 private static final String DESCR_STRING = "Ljava/lang/String;";
72 private static final String DESCR_OBJECT = "Ljava/lang/Object;";
73 private static final String DESCR_CTOR_SERIALIZED_LAMBDA
74 = "(" + DESCR_CLASS + DESCR_STRING + DESCR_STRING + DESCR_STRING + "I"
75 + DESCR_STRING + DESCR_STRING + DESCR_STRING + DESCR_STRING + "[" + DESCR_OBJECT + ")V";
76
77 private static final String DESCR_CTOR_NOT_SERIALIZABLE_EXCEPTION = "(Ljava/lang/String;)V";
78 private static final String[] SER_HOSTILE_EXCEPTIONS = new String[] {NAME_NOT_SERIALIZABLE_EXCEPTION};
79
80 private static final String[] EMPTY_STRING_ARRAY = new String[0];
81
82 // For dumping generated classes to disk, for debugging purposes
83 private static final ClassFileDumper lambdaProxyClassFileDumper;
84
85 private static final boolean disableEagerInitialization;
86
87 // condy to load implMethod from class data
88 private static final ConstantDynamic implMethodCondy;
89
90 static {
91 // To dump the lambda proxy classes, set this system property:
92 // -Djdk.invoke.LambdaMetafactory.dumpProxyClassFiles
93 // or -Djdk.invoke.LambdaMetafactory.dumpProxyClassFiles=true
94 final String dumpProxyClassesKey = "jdk.invoke.LambdaMetafactory.dumpProxyClassFiles";
95 lambdaProxyClassFileDumper = ClassFileDumper.getInstance(dumpProxyClassesKey, "DUMP_LAMBDA_PROXY_CLASS_FILES");
96
97 final String disableEagerInitializationKey = "jdk.internal.lambda.disableEagerInitialization";
98 disableEagerInitialization = GetBooleanAction.privilegedGetProperty(disableEagerInitializationKey);
99
100 // condy to load implMethod from class data
101 MethodType classDataMType = methodType(Object.class, MethodHandles.Lookup.class, String.class, Class.class);
102 Handle classDataBsm = new Handle(H_INVOKESTATIC, Type.getInternalName(MethodHandles.class), "classData",
103 classDataMType.descriptorString(), false);
104 implMethodCondy = new ConstantDynamic(ConstantDescs.DEFAULT_NAME, MethodHandle.class.descriptorString(), classDataBsm);
105 }
106
107 // See context values in AbstractValidatingLambdaMetafactory
108 private final String implMethodClassName; // Name of type containing implementation "CC"
109 private final String implMethodName; // Name of implementation method "impl"
110 private final String implMethodDesc; // Type descriptor for implementation methods "(I)Ljava/lang/String;"
111 private final MethodType constructorType; // Generated class constructor type "(CC)void"
112 private final ClassWriter cw; // ASM class writer
113 private final String[] argNames; // Generated names for the constructor arguments
114 private final String[] argDescs; // Type descriptors for the constructor arguments
115 private final String lambdaClassName; // Generated name for the generated class "X$$Lambda"
116 private final boolean useImplMethodHandle; // use MethodHandle invocation instead of symbolic bytecode invocation
117
118 /**
119 * General meta-factory constructor, supporting both standard cases and
120 * allowing for uncommon options such as serialization or bridging.
121 *
122 * @param caller Stacked automatically by VM; represents a lookup context
123 * with the accessibility privileges of the caller.
124 * @param factoryType Stacked automatically by VM; the signature of the
125 * invoked method, which includes the expected static
126 * type of the returned lambda object, and the static
127 * types of the captured arguments for the lambda. In
128 * the event that the implementation method is an
129 * instance method, the first argument in the invocation
130 * signature will correspond to the receiver.
131 * @param interfaceMethodName Name of the method in the functional interface to
132 * which the lambda or method reference is being
133 * converted, represented as a String.
134 * @param interfaceMethodType Type of the method in the functional interface to
135 * which the lambda or method reference is being
136 * converted, represented as a MethodType.
137 * @param implementation The implementation method which should be called (with
138 * suitable adaptation of argument types, return types,
139 * and adjustment for captured arguments) when methods of
140 * the resulting functional interface instance are invoked.
141 * @param dynamicMethodType The signature of the primary functional
142 * interface method after type variables are
143 * substituted with their instantiation from
144 * the capture site
145 * @param isSerializable Should the lambda be made serializable? If set,
146 * either the target type or one of the additional SAM
147 * types must extend {@code Serializable}.
148 * @param altInterfaces Additional interfaces which the lambda object
149 * should implement.
150 * @param altMethods Method types for additional signatures to be
151 * implemented by invoking the implementation method
152 * @throws LambdaConversionException If any of the meta-factory protocol
153 * invariants are violated
154 * @throws SecurityException If a security manager is present, and it
155 * <a href="MethodHandles.Lookup.html#secmgr">denies access</a>
156 * from {@code caller} to the package of {@code implementation}.
157 */
158 public InnerClassLambdaMetafactory(MethodHandles.Lookup caller,
159 MethodType factoryType,
160 String interfaceMethodName,
161 MethodType interfaceMethodType,
162 MethodHandle implementation,
163 MethodType dynamicMethodType,
164 boolean isSerializable,
165 Class<?>[] altInterfaces,
166 MethodType[] altMethods)
167 throws LambdaConversionException {
168 super(caller, factoryType, interfaceMethodName, interfaceMethodType,
169 implementation, dynamicMethodType,
170 isSerializable, altInterfaces, altMethods);
171 implMethodClassName = implClass.getName().replace('.', '/');
172 implMethodName = implInfo.getName();
173 implMethodDesc = implInfo.getMethodType().toMethodDescriptorString();
174 constructorType = factoryType.changeReturnType(Void.TYPE);
175 lambdaClassName = lambdaClassName(targetClass);
176 // If the target class invokes a protected method inherited from a
177 // superclass in a different package, or does 'invokespecial', the
178 // lambda class has no access to the resolved method, or does
179 // 'invokestatic' on a hidden class which cannot be resolved by name.
180 // Instead, we need to pass the live implementation method handle to
181 // the proxy class to invoke directly. (javac prefers to avoid this
182 // situation by generating bridges in the target class)
183 useImplMethodHandle = (Modifier.isProtected(implInfo.getModifiers()) &&
184 !VerifyAccess.isSamePackage(targetClass, implInfo.getDeclaringClass())) ||
185 implKind == H_INVOKESPECIAL ||
186 implKind == H_INVOKESTATIC && implClass.isHidden();
187 cw = new ClassWriter(ClassWriter.COMPUTE_MAXS);
188 int parameterCount = factoryType.parameterCount();
189 if (parameterCount > 0) {
190 argNames = new String[parameterCount];
191 argDescs = new String[parameterCount];
192 for (int i = 0; i < parameterCount; i++) {
193 argNames[i] = "arg$" + (i + 1);
194 argDescs[i] = BytecodeDescriptor.unparse(factoryType.parameterType(i));
195 }
196 } else {
197 argNames = argDescs = EMPTY_STRING_ARRAY;
198 }
199 }
200
201 private static String lambdaClassName(Class<?> targetClass) {
202 String name = targetClass.getName();
203 if (targetClass.isHidden()) {
204 // use the original class name
205 name = name.replace('/', '_');
206 }
207 return name.replace('.', '/') + "$$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.asType(methodType(Object.class)).invokeExact();
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 String[] interfaceNames;
304 String interfaceName = interfaceClass.getName().replace('.', '/');
305 boolean accidentallySerializable = !isSerializable && Serializable.class.isAssignableFrom(interfaceClass);
306 if (altInterfaces.length == 0) {
307 interfaceNames = new String[]{interfaceName};
308 } else {
309 // Assure no duplicate interfaces (ClassFormatError)
310 Set<String> itfs = LinkedHashSet.newLinkedHashSet(altInterfaces.length + 1);
311 itfs.add(interfaceName);
312 for (Class<?> i : altInterfaces) {
313 itfs.add(i.getName().replace('.', '/'));
314 accidentallySerializable |= !isSerializable && Serializable.class.isAssignableFrom(i);
315 }
316 interfaceNames = itfs.toArray(new String[itfs.size()]);
317 }
318
319 cw.visit(CLASSFILE_VERSION, ACC_SUPER + ACC_FINAL + ACC_SYNTHETIC,
320 lambdaClassName, null,
321 JAVA_LANG_OBJECT, interfaceNames);
322
323 // Generate final fields to be filled in by constructor
324 for (int i = 0; i < argDescs.length; i++) {
325 FieldVisitor fv = cw.visitField(ACC_PRIVATE + ACC_FINAL,
326 argNames[i],
327 argDescs[i],
328 null, null);
329 fv.visitEnd();
330 }
331
332 generateConstructor();
333
334 if (factoryType.parameterCount() == 0 && disableEagerInitialization) {
335 generateClassInitializer();
336 }
337
338 // Forward the SAM method
339 MethodVisitor mv = cw.visitMethod(ACC_PUBLIC, interfaceMethodName,
340 interfaceMethodType.toMethodDescriptorString(), null, null);
341 new ForwardingMethodGenerator(mv).generate(interfaceMethodType);
342
343 // Forward the altMethods
344 if (altMethods != null) {
345 for (MethodType mt : altMethods) {
346 mv = cw.visitMethod(ACC_PUBLIC, interfaceMethodName,
347 mt.toMethodDescriptorString(), null, null);
348 new ForwardingMethodGenerator(mv).generate(mt);
349 }
350 }
351
352 if (isSerializable)
353 generateSerializationFriendlyMethods();
354 else if (accidentallySerializable)
355 generateSerializationHostileMethods();
356
357 cw.visitEnd();
358
359 // Define the generated class in this VM.
360
361 final byte[] classBytes = cw.toByteArray();
362 try {
363 // this class is linked at the indy callsite; so define a hidden nestmate
364 var classdata = useImplMethodHandle? implementation : null;
365 return caller.makeHiddenClassDefiner(lambdaClassName, classBytes, Set.of(NESTMATE, STRONG), lambdaProxyClassFileDumper)
366 .defineClass(!disableEagerInitialization, classdata);
367
368 } catch (Throwable t) {
369 throw new InternalError(t);
370 }
371 }
372
373 /**
374 * Generate a static field and a static initializer that sets this field to an instance of the lambda
375 */
376 private void generateClassInitializer() {
377 String lambdaTypeDescriptor = factoryType.returnType().descriptorString();
378
379 // Generate the static final field that holds the lambda singleton
380 FieldVisitor fv = cw.visitField(ACC_PRIVATE | ACC_STATIC | ACC_FINAL,
381 LAMBDA_INSTANCE_FIELD, lambdaTypeDescriptor, null, null);
382 fv.visitEnd();
383
384 // Instantiate the lambda and store it to the static final field
385 MethodVisitor clinit = cw.visitMethod(ACC_STATIC, "<clinit>", "()V", null, null);
386 clinit.visitCode();
387
388 clinit.visitTypeInsn(NEW, lambdaClassName);
389 clinit.visitInsn(Opcodes.DUP);
390 assert factoryType.parameterCount() == 0;
391 clinit.visitMethodInsn(INVOKESPECIAL, lambdaClassName, NAME_CTOR, constructorType.toMethodDescriptorString(), false);
392 clinit.visitFieldInsn(PUTSTATIC, lambdaClassName, LAMBDA_INSTANCE_FIELD, lambdaTypeDescriptor);
393
394 clinit.visitInsn(RETURN);
395 clinit.visitMaxs(-1, -1);
396 clinit.visitEnd();
397 }
398
399 /**
400 * Generate the constructor for the class
401 */
402 private void generateConstructor() {
403 // Generate constructor
404 MethodVisitor ctor = cw.visitMethod(ACC_PRIVATE, NAME_CTOR,
405 constructorType.toMethodDescriptorString(), null, null);
406 ctor.visitCode();
407 ctor.visitVarInsn(ALOAD, 0);
408 ctor.visitMethodInsn(INVOKESPECIAL, JAVA_LANG_OBJECT, NAME_CTOR,
409 METHOD_DESCRIPTOR_VOID, false);
410 int parameterCount = factoryType.parameterCount();
411 for (int i = 0, lvIndex = 0; i < parameterCount; i++) {
412 ctor.visitVarInsn(ALOAD, 0);
413 Class<?> argType = factoryType.parameterType(i);
414 ctor.visitVarInsn(getLoadOpcode(argType), lvIndex + 1);
415 lvIndex += getParameterSize(argType);
416 ctor.visitFieldInsn(PUTFIELD, lambdaClassName, argNames[i], argDescs[i]);
417 }
418 ctor.visitInsn(RETURN);
419 // Maxs computed by ClassWriter.COMPUTE_MAXS, these arguments ignored
420 ctor.visitMaxs(-1, -1);
421 ctor.visitEnd();
422 }
423
424 /**
425 * Generate a writeReplace method that supports serialization
426 */
427 private void generateSerializationFriendlyMethods() {
428 TypeConvertingMethodAdapter mv
429 = new TypeConvertingMethodAdapter(
430 cw.visitMethod(ACC_PRIVATE + ACC_FINAL,
431 NAME_METHOD_WRITE_REPLACE, DESCR_METHOD_WRITE_REPLACE,
432 null, null));
433
434 mv.visitCode();
435 mv.visitTypeInsn(NEW, NAME_SERIALIZED_LAMBDA);
436 mv.visitInsn(DUP);
437 mv.visitLdcInsn(Type.getType(targetClass));
438 mv.visitLdcInsn(factoryType.returnType().getName().replace('.', '/'));
439 mv.visitLdcInsn(interfaceMethodName);
440 mv.visitLdcInsn(interfaceMethodType.toMethodDescriptorString());
441 mv.visitLdcInsn(implInfo.getReferenceKind());
442 mv.visitLdcInsn(implInfo.getDeclaringClass().getName().replace('.', '/'));
443 mv.visitLdcInsn(implInfo.getName());
444 mv.visitLdcInsn(implInfo.getMethodType().toMethodDescriptorString());
445 mv.visitLdcInsn(dynamicMethodType.toMethodDescriptorString());
446 mv.iconst(argDescs.length);
447 mv.visitTypeInsn(ANEWARRAY, JAVA_LANG_OBJECT);
448 for (int i = 0; i < argDescs.length; i++) {
449 mv.visitInsn(DUP);
450 mv.iconst(i);
451 mv.visitVarInsn(ALOAD, 0);
452 mv.visitFieldInsn(GETFIELD, lambdaClassName, argNames[i], argDescs[i]);
453 mv.boxIfTypePrimitive(Type.getType(argDescs[i]));
454 mv.visitInsn(AASTORE);
455 }
456 mv.visitMethodInsn(INVOKESPECIAL, NAME_SERIALIZED_LAMBDA, NAME_CTOR,
457 DESCR_CTOR_SERIALIZED_LAMBDA, false);
458 mv.visitInsn(ARETURN);
459 // Maxs computed by ClassWriter.COMPUTE_MAXS, these arguments ignored
460 mv.visitMaxs(-1, -1);
461 mv.visitEnd();
462 }
463
464 /**
465 * Generate a readObject/writeObject method that is hostile to serialization
466 */
467 private void generateSerializationHostileMethods() {
468 MethodVisitor mv = cw.visitMethod(ACC_PRIVATE + ACC_FINAL,
469 NAME_METHOD_WRITE_OBJECT, DESCR_METHOD_WRITE_OBJECT,
470 null, SER_HOSTILE_EXCEPTIONS);
471 mv.visitCode();
472 mv.visitTypeInsn(NEW, NAME_NOT_SERIALIZABLE_EXCEPTION);
473 mv.visitInsn(DUP);
474 mv.visitLdcInsn("Non-serializable lambda");
475 mv.visitMethodInsn(INVOKESPECIAL, NAME_NOT_SERIALIZABLE_EXCEPTION, NAME_CTOR,
476 DESCR_CTOR_NOT_SERIALIZABLE_EXCEPTION, false);
477 mv.visitInsn(ATHROW);
478 mv.visitMaxs(-1, -1);
479 mv.visitEnd();
480
481 mv = cw.visitMethod(ACC_PRIVATE + ACC_FINAL,
482 NAME_METHOD_READ_OBJECT, DESCR_METHOD_READ_OBJECT,
483 null, SER_HOSTILE_EXCEPTIONS);
484 mv.visitCode();
485 mv.visitTypeInsn(NEW, NAME_NOT_SERIALIZABLE_EXCEPTION);
486 mv.visitInsn(DUP);
487 mv.visitLdcInsn("Non-serializable lambda");
488 mv.visitMethodInsn(INVOKESPECIAL, NAME_NOT_SERIALIZABLE_EXCEPTION, NAME_CTOR,
489 DESCR_CTOR_NOT_SERIALIZABLE_EXCEPTION, false);
490 mv.visitInsn(ATHROW);
491 mv.visitMaxs(-1, -1);
492 mv.visitEnd();
493 }
494
495 /**
496 * This class generates a method body which calls the lambda implementation
497 * method, converting arguments, as needed.
498 */
499 private class ForwardingMethodGenerator extends TypeConvertingMethodAdapter {
500
501 ForwardingMethodGenerator(MethodVisitor mv) {
502 super(mv);
503 }
504
505 void generate(MethodType methodType) {
506 visitCode();
507
508 if (implKind == MethodHandleInfo.REF_newInvokeSpecial) {
509 visitTypeInsn(NEW, implMethodClassName);
510 visitInsn(DUP);
511 }
512 if (useImplMethodHandle) {
513 visitLdcInsn(implMethodCondy);
514 }
515 for (int i = 0; i < argNames.length; i++) {
516 visitVarInsn(ALOAD, 0);
517 visitFieldInsn(GETFIELD, lambdaClassName, argNames[i], argDescs[i]);
518 }
519
520 convertArgumentTypes(methodType);
521
522 if (useImplMethodHandle) {
523 MethodType mtype = implInfo.getMethodType();
524 if (implKind != MethodHandleInfo.REF_invokeStatic) {
525 mtype = mtype.insertParameterTypes(0, implClass);
526 }
527 visitMethodInsn(INVOKEVIRTUAL, "java/lang/invoke/MethodHandle",
528 "invokeExact", mtype.descriptorString(), false);
529 } else {
530 // Invoke the method we want to forward to
531 visitMethodInsn(invocationOpcode(), implMethodClassName,
532 implMethodName, implMethodDesc,
533 implClass.isInterface());
534 }
535 // Convert the return value (if any) and return it
536 // Note: if adapting from non-void to void, the 'return'
537 // instruction will pop the unneeded result
538 Class<?> implReturnClass = implMethodType.returnType();
539 Class<?> samReturnClass = methodType.returnType();
540 convertType(implReturnClass, samReturnClass, samReturnClass);
541 visitInsn(getReturnOpcode(samReturnClass));
542 // Maxs computed by ClassWriter.COMPUTE_MAXS,these arguments ignored
543 visitMaxs(-1, -1);
544 visitEnd();
545 }
546
547 private void convertArgumentTypes(MethodType samType) {
548 int lvIndex = 0;
549 int samParametersLength = samType.parameterCount();
550 int captureArity = factoryType.parameterCount();
551 for (int i = 0; i < samParametersLength; i++) {
552 Class<?> argType = samType.parameterType(i);
553 visitVarInsn(getLoadOpcode(argType), lvIndex + 1);
554 lvIndex += getParameterSize(argType);
555 convertType(argType, implMethodType.parameterType(captureArity + i), dynamicMethodType.parameterType(i));
556 }
557 }
558
559 private int invocationOpcode() throws InternalError {
560 return switch (implKind) {
561 case MethodHandleInfo.REF_invokeStatic -> INVOKESTATIC;
562 case MethodHandleInfo.REF_newInvokeSpecial -> INVOKESPECIAL;
563 case MethodHandleInfo.REF_invokeVirtual -> INVOKEVIRTUAL;
564 case MethodHandleInfo.REF_invokeInterface -> INVOKEINTERFACE;
565 case MethodHandleInfo.REF_invokeSpecial -> INVOKESPECIAL;
566 default -> throw new InternalError("Unexpected invocation kind: " + implKind);
567 };
568 }
569 }
570
571 static int getParameterSize(Class<?> c) {
572 if (c == Void.TYPE) {
573 return 0;
574 } else if (c == Long.TYPE || c == Double.TYPE) {
575 return 2;
576 }
577 return 1;
578 }
579
580 static int getLoadOpcode(Class<?> c) {
581 if(c == Void.TYPE) {
582 throw new InternalError("Unexpected void type of load opcode");
583 }
584 return ILOAD + getOpcodeOffset(c);
585 }
586
587 static int getReturnOpcode(Class<?> c) {
588 if(c == Void.TYPE) {
589 return RETURN;
590 }
591 return IRETURN + getOpcodeOffset(c);
592 }
593
594 private static int getOpcodeOffset(Class<?> c) {
595 if (c.isPrimitive()) {
596 if (c == Long.TYPE) {
597 return 1;
598 } else if (c == Float.TYPE) {
599 return 2;
600 } else if (c == Double.TYPE) {
601 return 3;
602 }
603 return 0;
604 } else {
605 return 4;
606 }
607 }
608
609 }