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src/java.base/share/classes/java/lang/invoke/InnerClassLambdaMetafactory.java

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 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.util.ClassFileDumper;
 30 import sun.invoke.util.VerifyAccess;
 31 import sun.security.action.GetBooleanAction;
 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.FieldBuilder;
 38 import java.lang.classfile.MethodBuilder;
 39 import java.lang.classfile.Opcode;
 40 import java.lang.classfile.TypeKind;


 41 import java.lang.constant.ClassDesc;
 42 import java.lang.constant.DynamicConstantDesc;
 43 import java.lang.constant.MethodTypeDesc;



 44 import java.lang.reflect.Modifier;
 45 import java.util.LinkedHashSet;
 46 import java.util.List;


 47 import java.util.Set;
 48 import java.util.function.Consumer;
 49 
 50 import static java.lang.classfile.ClassFile.*;
 51 import java.lang.classfile.attribute.ExceptionsAttribute;
 52 import java.lang.classfile.constantpool.ClassEntry;
 53 import java.lang.classfile.constantpool.ConstantPoolBuilder;
 54 import java.lang.classfile.constantpool.MethodRefEntry;
 55 import static java.lang.constant.ConstantDescs.*;
 56 import static java.lang.invoke.MethodHandleNatives.Constants.NESTMATE_CLASS;
 57 import static java.lang.invoke.MethodHandleNatives.Constants.STRONG_LOADER_LINK;
 58 import static java.lang.invoke.MethodHandles.Lookup.ClassOption.NESTMATE;
 59 import static java.lang.invoke.MethodHandles.Lookup.ClassOption.STRONG;
 60 import static java.lang.invoke.MethodType.methodType;
 61 import jdk.internal.constant.ConstantUtils;
 62 import jdk.internal.constant.MethodTypeDescImpl;
 63 import jdk.internal.constant.ReferenceClassDescImpl;
 64 import sun.invoke.util.Wrapper;
 65 
 66 /**
 67  * Lambda metafactory implementation which dynamically creates an
 68  * inner-class-like class per lambda callsite.
 69  *
 70  * @see LambdaMetafactory
 71  */
 72 /* package */ final class InnerClassLambdaMetafactory extends AbstractValidatingLambdaMetafactory {
 73     private static final String LAMBDA_INSTANCE_FIELD = "LAMBDA_INSTANCE$";
 74     private static final String[] EMPTY_STRING_ARRAY = new String[0];
 75     private static final ClassDesc[] EMPTY_CLASSDESC_ARRAY = ConstantUtils.EMPTY_CLASSDESC;
 76 








 77     // For dumping generated classes to disk, for debugging purposes
 78     private static final ClassFileDumper lambdaProxyClassFileDumper;
 79 
 80     private static final boolean disableEagerInitialization;
 81 



 82     static {
 83         // To dump the lambda proxy classes, set this system property:
 84         //    -Djdk.invoke.LambdaMetafactory.dumpProxyClassFiles
 85         // or -Djdk.invoke.LambdaMetafactory.dumpProxyClassFiles=true
 86         final String dumpProxyClassesKey = "jdk.invoke.LambdaMetafactory.dumpProxyClassFiles";
 87         lambdaProxyClassFileDumper = ClassFileDumper.getInstance(dumpProxyClassesKey, "DUMP_LAMBDA_PROXY_CLASS_FILES");
 88 
 89         final String disableEagerInitializationKey = "jdk.internal.lambda.disableEagerInitialization";
 90         disableEagerInitialization = GetBooleanAction.privilegedGetProperty(disableEagerInitializationKey);
 91     }
 92 
 93     // See context values in AbstractValidatingLambdaMetafactory
 94     private final ClassDesc implMethodClassDesc;     // Name of type containing implementation "CC"
 95     private final String implMethodName;             // Name of implementation method "impl"
 96     private final MethodTypeDesc implMethodDesc;     // Type descriptor for implementation methods "(I)Ljava/lang/String;"
 97     private final MethodType constructorType;        // Generated class constructor type "(CC)void"
 98     private final MethodTypeDesc constructorTypeDesc;// Type descriptor for the generated class constructor type "(CC)void"
 99     private final String[] argNames;                 // Generated names for the constructor arguments
100     private final ClassDesc[] argDescs;              // Type descriptors for the constructor arguments
101     private final String lambdaClassName;            // Generated name for the generated class "X$$Lambda$1"

134      *                       either the target type or one of the additional SAM
135      *                       types must extend {@code Serializable}.
136      * @param altInterfaces Additional interfaces which the lambda object
137      *                      should implement.
138      * @param altMethods Method types for additional signatures to be
139      *                   implemented by invoking the implementation method
140      * @throws LambdaConversionException If any of the meta-factory protocol
141      *         invariants are violated
142      * @throws SecurityException If a security manager is present, and it
143      *         <a href="MethodHandles.Lookup.html#secmgr">denies access</a>
144      *         from {@code caller} to the package of {@code implementation}.
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(ReferenceClassDescImpl.ofValidated(ConstantUtils.concat("L", 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         if (parameterCount > 0) {
178             argNames = new String[parameterCount];

299             // Assure no duplicate interfaces (ClassFormatError)
300             Set<ClassDesc> itfs = LinkedHashSet.newLinkedHashSet(altInterfaces.length + 1);
301             itfs.add(interfaceDesc);
302             for (Class<?> i : altInterfaces) {
303                 itfs.add(classDesc(i));
304                 accidentallySerializable |= !isSerializable && Serializable.class.isAssignableFrom(i);
305             }
306             interfaces = List.copyOf(itfs);
307         }
308         final boolean finalAccidentallySerializable = accidentallySerializable;
309         final byte[] classBytes = ClassFile.of().build(lambdaClassEntry, pool, new Consumer<ClassBuilder>() {
310             @Override
311             public void accept(ClassBuilder clb) {
312                 clb.withFlags(ACC_SUPER | ACC_FINAL | ACC_SYNTHETIC)
313                    .withInterfaceSymbols(interfaces);
314                 // Generate final fields to be filled in by constructor
315                 for (int i = 0; i < argDescs.length; i++) {
316                     clb.withField(argNames[i], argDescs[i], ACC_PRIVATE | ACC_FINAL);
317                 }
318 





319                 generateConstructor(clb);
320 
321                 if (factoryType.parameterCount() == 0 && disableEagerInitialization) {
322                     generateClassInitializer(clb);
323                 }
324 
325                 // Forward the SAM method
326                 clb.withMethodBody(interfaceMethodName,
327                         methodDesc(interfaceMethodType),
328                         ACC_PUBLIC,
329                         forwardingMethod(interfaceMethodType));
330 
331                 // Forward the bridges
332                 if (altMethods != null) {
333                     for (MethodType mt : altMethods) {
334                         clb.withMethodBody(interfaceMethodName,
335                                 methodDesc(mt),
336                                 ACC_PUBLIC | ACC_BRIDGE,
337                                 forwardingMethod(mt));
338                     }
339                 }
340 
341                 if (isSerializable)
342                     generateSerializationFriendlyMethods(clb);
343                 else if (finalAccidentallySerializable)
344                     generateSerializationHostileMethods(clb);




345             }
346         });
347 
348         // Define the generated class in this VM.
349 
350         try {
351             // this class is linked at the indy callsite; so define a hidden nestmate
352             var classdata = useImplMethodHandle? implementation : null;







353             return caller.makeHiddenClassDefiner(lambdaClassName, classBytes, lambdaProxyClassFileDumper, NESTMATE_CLASS | STRONG_LOADER_LINK)
354                          .defineClass(!disableEagerInitialization, classdata);
355 
356         } catch (Throwable t) {
357             throw new InternalError(t);
358         }
359     }
360 
361     /**
362      * Generate a static field and a static initializer that sets this field to an instance of the lambda
363      */
364     private void generateClassInitializer(ClassBuilder clb) {
365         ClassDesc lambdaTypeDescriptor = classDesc(factoryType.returnType());
366 
367         // Generate the static final field that holds the lambda singleton
368         clb.withField(LAMBDA_INSTANCE_FIELD, lambdaTypeDescriptor, ACC_PRIVATE | ACC_STATIC | ACC_FINAL);
369 
370         // Instantiate the lambda and store it to the static final field
371         clb.withMethodBody(CLASS_INIT_NAME, MTD_void, ACC_STATIC, new Consumer<>() {
372             @Override

382     }
383 
384     /**
385      * Generate the constructor for the class
386      */
387     private void generateConstructor(ClassBuilder clb) {
388         // Generate constructor
389         clb.withMethodBody(INIT_NAME, constructorTypeDesc, ACC_PRIVATE,
390                 new Consumer<>() {
391                     @Override
392                     public void accept(CodeBuilder cob) {
393                         cob.aload(0)
394                            .invokespecial(CD_Object, INIT_NAME, MTD_void);
395                         int parameterCount = factoryType.parameterCount();
396                         for (int i = 0; i < parameterCount; i++) {
397                             cob.aload(0);
398                             Class<?> argType = factoryType.parameterType(i);
399                             cob.loadLocal(TypeKind.from(argType), cob.parameterSlot(i));
400                             cob.putfield(pool.fieldRefEntry(lambdaClassEntry, pool.nameAndTypeEntry(argNames[i], argDescs[i])));
401                         }



402                         cob.return_();
403                     }
404                 });
405     }
406 



































































407     private static class SerializationSupport {
408         // Serialization support
409         private static final ClassDesc CD_SerializedLambda = ReferenceClassDescImpl.ofValidated("Ljava/lang/invoke/SerializedLambda;");
410         private static final ClassDesc CD_ObjectOutputStream = ReferenceClassDescImpl.ofValidated("Ljava/io/ObjectOutputStream;");
411         private static final ClassDesc CD_ObjectInputStream = ReferenceClassDescImpl.ofValidated("Ljava/io/ObjectInputStream;");
412         private static final MethodTypeDesc MTD_Object = MethodTypeDescImpl.ofValidated(CD_Object);
413         private static final MethodTypeDesc MTD_void_ObjectOutputStream = MethodTypeDescImpl.ofValidated(CD_void, CD_ObjectOutputStream);
414         private static final MethodTypeDesc MTD_void_ObjectInputStream = MethodTypeDescImpl.ofValidated(CD_void, CD_ObjectInputStream);
415 
416         private static final String NAME_METHOD_WRITE_REPLACE = "writeReplace";
417         private static final String NAME_METHOD_READ_OBJECT = "readObject";
418         private static final String NAME_METHOD_WRITE_OBJECT = "writeObject";
419 
420         static final ClassDesc CD_NotSerializableException = ReferenceClassDescImpl.ofValidated("Ljava/io/NotSerializableException;");
421         static final MethodTypeDesc MTD_CTOR_NOT_SERIALIZABLE_EXCEPTION = MethodTypeDescImpl.ofValidated(CD_void, CD_String);
422         static final MethodTypeDesc MTD_CTOR_SERIALIZED_LAMBDA = MethodTypeDescImpl.ofValidated(CD_void,
423                 CD_Class, CD_String, CD_String, CD_String, CD_int, CD_String, CD_String, CD_String, CD_String, ReferenceClassDescImpl.ofValidated("[Ljava/lang/Object;"));
424 
425     }
426 

443                            .ldc(implInfo.getName())
444                            .ldc(implInfo.getMethodType().toMethodDescriptorString())
445                            .ldc(dynamicMethodType.toMethodDescriptorString())
446                            .loadConstant(argDescs.length)
447                            .anewarray(CD_Object);
448                         for (int i = 0; i < argDescs.length; i++) {
449                             cob.dup()
450                                .loadConstant(i)
451                                .aload(0)
452                                .getfield(pool.fieldRefEntry(lambdaClassEntry, pool.nameAndTypeEntry(argNames[i], argDescs[i])));
453                             TypeConvertingMethodAdapter.boxIfTypePrimitive(cob, TypeKind.from(argDescs[i]));
454                             cob.aastore();
455                         }
456                         cob.invokespecial(SerializationSupport.CD_SerializedLambda, INIT_NAME,
457                                           SerializationSupport.MTD_CTOR_SERIALIZED_LAMBDA)
458                            .areturn();
459                     }
460                 });
461     }
462 














463     /**
464      * Generate a readObject/writeObject method that is hostile to serialization
465      */
466     private void generateSerializationHostileMethods(ClassBuilder clb) {
467         var hostileMethod = new Consumer<MethodBuilder>() {
468             @Override
469             public void accept(MethodBuilder mb) {
470                 ConstantPoolBuilder cp = mb.constantPool();
471                 ClassEntry nseCE = cp.classEntry(SerializationSupport.CD_NotSerializableException);
472                 mb.with(ExceptionsAttribute.of(nseCE))
473                         .withCode(new Consumer<CodeBuilder>() {
474                             @Override
475                             public void accept(CodeBuilder cob) {
476                                 cob.new_(nseCE)
477                                         .dup()
478                                         .ldc("Non-serializable lambda")
479                                         .invokespecial(cp.methodRefEntry(nseCE, cp.nameAndTypeEntry(INIT_NAME,
480                                                 SerializationSupport.MTD_CTOR_NOT_SERIALIZABLE_EXCEPTION)))
481                                         .athrow();
482                             }

486         clb.withMethod(SerializationSupport.NAME_METHOD_WRITE_OBJECT, SerializationSupport.MTD_void_ObjectOutputStream,
487                 ACC_PRIVATE + ACC_FINAL, hostileMethod);
488         clb.withMethod(SerializationSupport.NAME_METHOD_READ_OBJECT, SerializationSupport.MTD_void_ObjectInputStream,
489                 ACC_PRIVATE + ACC_FINAL, hostileMethod);
490     }
491 
492     /**
493      * This method generates a method body which calls the lambda implementation
494      * method, converting arguments, as needed.
495      */
496     Consumer<CodeBuilder> forwardingMethod(MethodType methodType) {
497         return new Consumer<>() {
498             @Override
499             public void accept(CodeBuilder cob) {
500                 if (implKind == MethodHandleInfo.REF_newInvokeSpecial) {
501                     cob.new_(implMethodClassDesc)
502                        .dup();
503                 }
504                 if (useImplMethodHandle) {
505                     ConstantPoolBuilder cp = cob.constantPool();
506                     cob.ldc(cp.constantDynamicEntry(cp.bsmEntry(cp.methodHandleEntry(BSM_CLASS_DATA), List.of()),
507                                                     cp.nameAndTypeEntry(DEFAULT_NAME, CD_MethodHandle)));
508                 }
509                 for (int i = 0; i < argNames.length; i++) {
510                     cob.aload(0)
511                        .getfield(pool.fieldRefEntry(lambdaClassEntry, pool.nameAndTypeEntry(argNames[i], argDescs[i])));
512                 }
513 
514                 convertArgumentTypes(cob, methodType);
515 
516                 if (useImplMethodHandle) {
517                     MethodType mtype = implInfo.getMethodType();
518                     if (implKind != MethodHandleInfo.REF_invokeStatic) {
519                         mtype = mtype.insertParameterTypes(0, implClass);
520                     }
521                     cob.invokevirtual(CD_MethodHandle, "invokeExact", methodDesc(mtype));
522                 } else {
523                     // Invoke the method we want to forward to
524                     cob.invoke(invocationOpcode(), implMethodClassDesc, implMethodName, implMethodDesc, implClass.isInterface());
525                 }
526                 // Convert the return value (if any) and return it
527                 // Note: if adapting from non-void to void, the 'return'
528                 // instruction will pop the unneeded result
529                 Class<?> implReturnClass = implMethodType.returnType();

 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.util.ClassFileDumper;
 30 import sun.invoke.util.VerifyAccess;
 31 import sun.security.action.GetBooleanAction;
 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.FieldBuilder;
 38 import java.lang.classfile.MethodBuilder;
 39 import java.lang.classfile.Opcode;
 40 import java.lang.classfile.TypeKind;
 41 import java.lang.classfile.constantpool.MethodHandleEntry;
 42 import java.lang.classfile.constantpool.NameAndTypeEntry;
 43 import java.lang.constant.ClassDesc;
 44 import java.lang.constant.DynamicConstantDesc;
 45 import java.lang.constant.MethodTypeDesc;
 46 import java.lang.invoke.MethodHandles.Lookup;
 47 import java.lang.module.Configuration;
 48 import java.lang.module.ModuleFinder;
 49 import java.lang.reflect.Modifier;
 50 import java.util.LinkedHashSet;
 51 import java.util.List;
 52 import java.util.Optional;
 53 import java.util.ServiceLoader;
 54 import java.util.Set;
 55 import java.util.function.Consumer;
 56 
 57 import static java.lang.classfile.ClassFile.*;
 58 import java.lang.classfile.attribute.ExceptionsAttribute;
 59 import java.lang.classfile.constantpool.ClassEntry;
 60 import java.lang.classfile.constantpool.ConstantPoolBuilder;
 61 import java.lang.classfile.constantpool.MethodRefEntry;
 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 static java.lang.invoke.MethodHandles.Lookup.ClassOption.NESTMATE;
 66 import static java.lang.invoke.MethodHandles.Lookup.ClassOption.STRONG;
 67 import static java.lang.invoke.MethodType.methodType;
 68 import jdk.internal.constant.ConstantUtils;
 69 import jdk.internal.constant.MethodTypeDescImpl;
 70 import jdk.internal.constant.ReferenceClassDescImpl;
 71 import sun.invoke.util.Wrapper;
 72 
 73 /**
 74  * Lambda metafactory implementation which dynamically creates an
 75  * inner-class-like class per lambda callsite.
 76  *
 77  * @see LambdaMetafactory
 78  */
 79 /* package */ final class InnerClassLambdaMetafactory extends AbstractValidatingLambdaMetafactory {
 80     private static final String LAMBDA_INSTANCE_FIELD = "LAMBDA_INSTANCE$";
 81     private static final String[] EMPTY_STRING_ARRAY = new String[0];
 82     private static final ClassDesc[] EMPTY_CLASSDESC_ARRAY = ConstantUtils.EMPTY_CLASSDESC;
 83 
 84     // Static builders to avoid lambdas
 85     record MethodBody(Consumer<CodeBuilder> code) implements Consumer<MethodBuilder> {
 86         @Override
 87         public void accept(MethodBuilder mb) {
 88             mb.withCode(code);
 89         }
 90     };
 91 
 92     // For dumping generated classes to disk, for debugging purposes
 93     private static final ClassFileDumper lambdaProxyClassFileDumper;
 94 
 95     private static final boolean disableEagerInitialization;
 96 
 97     private static final String NAME_METHOD_QUOTED = "quoted";
 98     private static final String quotedInstanceFieldName = "quoted";
 99 
100     static {
101         // To dump the lambda proxy classes, set this system property:
102         //    -Djdk.invoke.LambdaMetafactory.dumpProxyClassFiles
103         // or -Djdk.invoke.LambdaMetafactory.dumpProxyClassFiles=true
104         final String dumpProxyClassesKey = "jdk.invoke.LambdaMetafactory.dumpProxyClassFiles";
105         lambdaProxyClassFileDumper = ClassFileDumper.getInstance(dumpProxyClassesKey, "DUMP_LAMBDA_PROXY_CLASS_FILES");
106 
107         final String disableEagerInitializationKey = "jdk.internal.lambda.disableEagerInitialization";
108         disableEagerInitialization = GetBooleanAction.privilegedGetProperty(disableEagerInitializationKey);
109     }
110 
111     // See context values in AbstractValidatingLambdaMetafactory
112     private final ClassDesc implMethodClassDesc;     // Name of type containing implementation "CC"
113     private final String implMethodName;             // Name of implementation method "impl"
114     private final MethodTypeDesc implMethodDesc;     // Type descriptor for implementation methods "(I)Ljava/lang/String;"
115     private final MethodType constructorType;        // Generated class constructor type "(CC)void"
116     private final MethodTypeDesc constructorTypeDesc;// Type descriptor for the generated class constructor type "(CC)void"
117     private final String[] argNames;                 // Generated names for the constructor arguments
118     private final ClassDesc[] argDescs;              // Type descriptors for the constructor arguments
119     private final String lambdaClassName;            // Generated name for the generated class "X$$Lambda$1"

152      *                       either the target type or one of the additional SAM
153      *                       types must extend {@code Serializable}.
154      * @param altInterfaces Additional interfaces which the lambda object
155      *                      should implement.
156      * @param altMethods Method types for additional signatures to be
157      *                   implemented by invoking the implementation method
158      * @throws LambdaConversionException If any of the meta-factory protocol
159      *         invariants are violated
160      * @throws SecurityException If a security manager is present, and it
161      *         <a href="MethodHandles.Lookup.html#secmgr">denies access</a>
162      *         from {@code caller} to the package of {@code implementation}.
163      */
164     public InnerClassLambdaMetafactory(MethodHandles.Lookup caller,
165                                        MethodType factoryType,
166                                        String interfaceMethodName,
167                                        MethodType interfaceMethodType,
168                                        MethodHandle implementation,
169                                        MethodType dynamicMethodType,
170                                        boolean isSerializable,
171                                        Class<?>[] altInterfaces,
172                                        MethodType[] altMethods,
173                                        MethodHandle reflectiveField)
174             throws LambdaConversionException {
175         super(caller, factoryType, interfaceMethodName, interfaceMethodType,
176               implementation, dynamicMethodType,
177               isSerializable, altInterfaces, altMethods, reflectiveField);
178         implMethodClassDesc = implClassDesc(implClass);
179         implMethodName = implInfo.getName();
180         implMethodDesc = methodDesc(implInfo.getMethodType());
181         constructorType = factoryType.changeReturnType(Void.TYPE);
182         lambdaClassName = lambdaClassName(targetClass);
183         lambdaClassEntry = pool.classEntry(ReferenceClassDescImpl.ofValidated(ConstantUtils.concat("L", lambdaClassName, ";")));
184         // If the target class invokes a protected method inherited from a
185         // superclass in a different package, or does 'invokespecial', the
186         // lambda class has no access to the resolved method, or does
187         // 'invokestatic' on a hidden class which cannot be resolved by name.
188         // Instead, we need to pass the live implementation method handle to
189         // the proxy class to invoke directly. (javac prefers to avoid this
190         // situation by generating bridges in the target class)
191         useImplMethodHandle = (Modifier.isProtected(implInfo.getModifiers()) &&
192                                !VerifyAccess.isSamePackage(targetClass, implInfo.getDeclaringClass())) ||
193                                implKind == MethodHandleInfo.REF_invokeSpecial ||
194                                implKind == MethodHandleInfo.REF_invokeStatic && implClass.isHidden();
195         int parameterCount = factoryType.parameterCount();
196         if (parameterCount > 0) {
197             argNames = new String[parameterCount];

318             // Assure no duplicate interfaces (ClassFormatError)
319             Set<ClassDesc> itfs = LinkedHashSet.newLinkedHashSet(altInterfaces.length + 1);
320             itfs.add(interfaceDesc);
321             for (Class<?> i : altInterfaces) {
322                 itfs.add(classDesc(i));
323                 accidentallySerializable |= !isSerializable && Serializable.class.isAssignableFrom(i);
324             }
325             interfaces = List.copyOf(itfs);
326         }
327         final boolean finalAccidentallySerializable = accidentallySerializable;
328         final byte[] classBytes = ClassFile.of().build(lambdaClassEntry, pool, new Consumer<ClassBuilder>() {
329             @Override
330             public void accept(ClassBuilder clb) {
331                 clb.withFlags(ACC_SUPER | ACC_FINAL | ACC_SYNTHETIC)
332                    .withInterfaceSymbols(interfaces);
333                 // Generate final fields to be filled in by constructor
334                 for (int i = 0; i < argDescs.length; i++) {
335                     clb.withField(argNames[i], argDescs[i], ACC_PRIVATE | ACC_FINAL);
336                 }
337 
338                 // if quotable, generate the field that will hold the value of quoted
339                 if (quotableOpField != null) {
340                     clb.withField(quotedInstanceFieldName, CodeReflectionSupport.CD_Quoted, ACC_PRIVATE + ACC_FINAL);
341                 }
342 
343                 generateConstructor(clb);
344 
345                 if (factoryType.parameterCount() == 0 && disableEagerInitialization) {
346                     generateClassInitializer(clb);
347                 }
348 
349                 // Forward the SAM method
350                 clb.withMethodBody(interfaceMethodName,
351                         methodDesc(interfaceMethodType),
352                         ACC_PUBLIC,
353                         forwardingMethod(interfaceMethodType));
354 
355                 // Forward the bridges
356                 if (altMethods != null) {
357                     for (MethodType mt : altMethods) {
358                         clb.withMethodBody(interfaceMethodName,
359                                 methodDesc(mt),
360                                 ACC_PUBLIC | ACC_BRIDGE,
361                                 forwardingMethod(mt));
362                     }
363                 }
364 
365                 if (isSerializable)
366                     generateSerializationFriendlyMethods(clb);
367                 else if (finalAccidentallySerializable)
368                     generateSerializationHostileMethods(clb);
369 
370                 if (quotableOpField != null) {
371                     generateQuotableMethod(clb);
372                 }
373             }
374         });
375 
376         // Define the generated class in this VM.
377 
378         try {
379             // this class is linked at the indy callsite; so define a hidden nestmate
380             List<?> classdata;
381             if (useImplMethodHandle || quotableOpField != null) {
382                 classdata = quotableOpField == null ?
383                         List.of(implementation) :
384                         List.of(implementation, quotableOpField, CodeReflectionSupport.HANDLE_MAKE_QUOTED);
385             } else {
386                 classdata = null;
387             }
388             return caller.makeHiddenClassDefiner(lambdaClassName, classBytes, lambdaProxyClassFileDumper, NESTMATE_CLASS | STRONG_LOADER_LINK)
389                          .defineClass(!disableEagerInitialization, classdata);
390 
391         } catch (Throwable t) {
392             throw new InternalError(t);
393         }
394     }
395 
396     /**
397      * Generate a static field and a static initializer that sets this field to an instance of the lambda
398      */
399     private void generateClassInitializer(ClassBuilder clb) {
400         ClassDesc lambdaTypeDescriptor = classDesc(factoryType.returnType());
401 
402         // Generate the static final field that holds the lambda singleton
403         clb.withField(LAMBDA_INSTANCE_FIELD, lambdaTypeDescriptor, ACC_PRIVATE | ACC_STATIC | ACC_FINAL);
404 
405         // Instantiate the lambda and store it to the static final field
406         clb.withMethodBody(CLASS_INIT_NAME, MTD_void, ACC_STATIC, new Consumer<>() {
407             @Override

417     }
418 
419     /**
420      * Generate the constructor for the class
421      */
422     private void generateConstructor(ClassBuilder clb) {
423         // Generate constructor
424         clb.withMethodBody(INIT_NAME, constructorTypeDesc, ACC_PRIVATE,
425                 new Consumer<>() {
426                     @Override
427                     public void accept(CodeBuilder cob) {
428                         cob.aload(0)
429                            .invokespecial(CD_Object, INIT_NAME, MTD_void);
430                         int parameterCount = factoryType.parameterCount();
431                         for (int i = 0; i < parameterCount; i++) {
432                             cob.aload(0);
433                             Class<?> argType = factoryType.parameterType(i);
434                             cob.loadLocal(TypeKind.from(argType), cob.parameterSlot(i));
435                             cob.putfield(pool.fieldRefEntry(lambdaClassEntry, pool.nameAndTypeEntry(argNames[i], argDescs[i])));
436                         }
437                         if (quotableOpField != null) {
438                             generateQuotedFieldInitializer(cob);
439                         }
440                         cob.return_();
441                     }
442                 });
443     }
444 
445     private void generateQuotedFieldInitializer(CodeBuilder cob) {
446         ConstantPoolBuilder cp = cob.constantPool();
447         MethodHandleEntry bsmDataAt = cp.methodHandleEntry(BSM_CLASS_DATA_AT);
448         NameAndTypeEntry natMH = cp.nameAndTypeEntry(DEFAULT_NAME, CD_MethodHandle);
449         // push the receiver on the stack for operand of put field instruction
450         cob.aload(0)
451            .ldc(cp.constantDynamicEntry(cp.bsmEntry(bsmDataAt, List.of(cp.intEntry(2))), natMH))
452         // load op string from field
453            .ldc(cp.constantDynamicEntry(cp.bsmEntry(bsmDataAt, List.of(cp.intEntry(1))), natMH));
454         MethodType mtype = quotableOpFieldInfo.getMethodType();
455         if (quotableOpFieldInfo.getReferenceKind() != MethodHandleInfo.REF_getStatic) {
456             mtype = mtype.insertParameterTypes(0, implClass);
457         }
458         cob.invokevirtual(CD_MethodHandle, "invokeExact", mtype.describeConstable().get());
459 
460         // load captured args in array
461 
462         int capturedArity = factoryType.parameterCount();
463         cob.loadConstant(capturedArity)
464            .anewarray(CD_Object);
465         // initialize quoted captures
466         for (int i = 0; i < capturedArity; i++) {
467             cob.dup()
468                .loadConstant(i)
469                .aload(0)
470                .getfield(lambdaClassEntry.asSymbol(), argNames[i], argDescs[i]);
471             TypeConvertingMethodAdapter.boxIfTypePrimitive(cob, TypeKind.from(argDescs[i]));
472             cob.aastore();
473         }
474 
475         // now create a Quoted from String and captured args Object[]
476 
477         cob.invokevirtual(CD_MethodHandle, "invokeExact", methodDesc(CodeReflectionSupport.HANDLE_MAKE_QUOTED.type()))
478            .putfield(lambdaClassEntry.asSymbol(), quotedInstanceFieldName, CodeReflectionSupport.CD_Quoted);
479     }
480 
481     static class CodeReflectionSupport {
482         static final Class<?> QUOTED_CLASS;
483         static final Class<?> QUOTABLE_CLASS;
484         static final MethodHandle HANDLE_MAKE_QUOTED;
485 
486         static {
487             try {
488                 // we know jdk.incubator code is there, no need to check
489                 ModuleLayer parent = ModuleLayer.boot();
490                 Configuration cf = parent.configuration()
491                         .resolve(ModuleFinder.of(), ModuleFinder.ofSystem(), Set.of("jdk.incubator.code"));
492                 ClassLoader scl = ClassLoader.getSystemClassLoader();
493                 ModuleLayer layer = parent.defineModulesWithOneLoader(cf, scl);
494                 QUOTED_CLASS = layer.findLoader("jdk.incubator.code")
495                         .loadClass("jdk.incubator.code.Quoted");
496                 QUOTABLE_CLASS = layer.findLoader("jdk.incubator.code")
497                         .loadClass("jdk.incubator.code.Quotable");
498                 Class<?> quotedHelper = layer.findLoader("jdk.incubator.code")
499                         .loadClass("jdk.incubator.code.internal.QuotedHelper");
500                 MethodHandle makeQuoted = Lookup.IMPL_LOOKUP.findStatic(quotedHelper, "makeQuoted",
501                         MethodType.methodType(QUOTED_CLASS, MethodHandles.Lookup.class, String.class, Object[].class));
502                 HANDLE_MAKE_QUOTED = makeQuoted.bindTo(Lookup.IMPL_LOOKUP);
503             } catch (Throwable ex) {
504                 throw new ExceptionInInitializerError(ex);
505             }
506         }
507 
508         static final ClassDesc CD_Quoted = QUOTED_CLASS.describeConstable().get();
509         static final MethodTypeDesc MTD_Quoted = MethodTypeDescImpl.ofValidated(CD_Quoted);
510     }
511 
512     private static class SerializationSupport {
513         // Serialization support
514         private static final ClassDesc CD_SerializedLambda = ReferenceClassDescImpl.ofValidated("Ljava/lang/invoke/SerializedLambda;");
515         private static final ClassDesc CD_ObjectOutputStream = ReferenceClassDescImpl.ofValidated("Ljava/io/ObjectOutputStream;");
516         private static final ClassDesc CD_ObjectInputStream = ReferenceClassDescImpl.ofValidated("Ljava/io/ObjectInputStream;");
517         private static final MethodTypeDesc MTD_Object = MethodTypeDescImpl.ofValidated(CD_Object);
518         private static final MethodTypeDesc MTD_void_ObjectOutputStream = MethodTypeDescImpl.ofValidated(CD_void, CD_ObjectOutputStream);
519         private static final MethodTypeDesc MTD_void_ObjectInputStream = MethodTypeDescImpl.ofValidated(CD_void, CD_ObjectInputStream);
520 
521         private static final String NAME_METHOD_WRITE_REPLACE = "writeReplace";
522         private static final String NAME_METHOD_READ_OBJECT = "readObject";
523         private static final String NAME_METHOD_WRITE_OBJECT = "writeObject";
524 
525         static final ClassDesc CD_NotSerializableException = ReferenceClassDescImpl.ofValidated("Ljava/io/NotSerializableException;");
526         static final MethodTypeDesc MTD_CTOR_NOT_SERIALIZABLE_EXCEPTION = MethodTypeDescImpl.ofValidated(CD_void, CD_String);
527         static final MethodTypeDesc MTD_CTOR_SERIALIZED_LAMBDA = MethodTypeDescImpl.ofValidated(CD_void,
528                 CD_Class, CD_String, CD_String, CD_String, CD_int, CD_String, CD_String, CD_String, CD_String, ReferenceClassDescImpl.ofValidated("[Ljava/lang/Object;"));
529 
530     }
531 

548                            .ldc(implInfo.getName())
549                            .ldc(implInfo.getMethodType().toMethodDescriptorString())
550                            .ldc(dynamicMethodType.toMethodDescriptorString())
551                            .loadConstant(argDescs.length)
552                            .anewarray(CD_Object);
553                         for (int i = 0; i < argDescs.length; i++) {
554                             cob.dup()
555                                .loadConstant(i)
556                                .aload(0)
557                                .getfield(pool.fieldRefEntry(lambdaClassEntry, pool.nameAndTypeEntry(argNames[i], argDescs[i])));
558                             TypeConvertingMethodAdapter.boxIfTypePrimitive(cob, TypeKind.from(argDescs[i]));
559                             cob.aastore();
560                         }
561                         cob.invokespecial(SerializationSupport.CD_SerializedLambda, INIT_NAME,
562                                           SerializationSupport.MTD_CTOR_SERIALIZED_LAMBDA)
563                            .areturn();
564                     }
565                 });
566     }
567 
568     /**
569      * Generate a writeReplace method that supports serialization
570      */
571     private void generateQuotableMethod(ClassBuilder clb) {
572         clb.withMethod(NAME_METHOD_QUOTED, CodeReflectionSupport.MTD_Quoted, ACC_PUBLIC + ACC_FINAL, new MethodBody(new Consumer<CodeBuilder>() {
573             @Override
574             public void accept(CodeBuilder cob) {
575                 cob.aload(0)
576                    .getfield(lambdaClassEntry.asSymbol(), quotedInstanceFieldName, CodeReflectionSupport.CD_Quoted)
577                    .areturn();
578             }
579         }));
580     }
581 
582     /**
583      * Generate a readObject/writeObject method that is hostile to serialization
584      */
585     private void generateSerializationHostileMethods(ClassBuilder clb) {
586         var hostileMethod = new Consumer<MethodBuilder>() {
587             @Override
588             public void accept(MethodBuilder mb) {
589                 ConstantPoolBuilder cp = mb.constantPool();
590                 ClassEntry nseCE = cp.classEntry(SerializationSupport.CD_NotSerializableException);
591                 mb.with(ExceptionsAttribute.of(nseCE))
592                         .withCode(new Consumer<CodeBuilder>() {
593                             @Override
594                             public void accept(CodeBuilder cob) {
595                                 cob.new_(nseCE)
596                                         .dup()
597                                         .ldc("Non-serializable lambda")
598                                         .invokespecial(cp.methodRefEntry(nseCE, cp.nameAndTypeEntry(INIT_NAME,
599                                                 SerializationSupport.MTD_CTOR_NOT_SERIALIZABLE_EXCEPTION)))
600                                         .athrow();
601                             }

605         clb.withMethod(SerializationSupport.NAME_METHOD_WRITE_OBJECT, SerializationSupport.MTD_void_ObjectOutputStream,
606                 ACC_PRIVATE + ACC_FINAL, hostileMethod);
607         clb.withMethod(SerializationSupport.NAME_METHOD_READ_OBJECT, SerializationSupport.MTD_void_ObjectInputStream,
608                 ACC_PRIVATE + ACC_FINAL, hostileMethod);
609     }
610 
611     /**
612      * This method generates a method body which calls the lambda implementation
613      * method, converting arguments, as needed.
614      */
615     Consumer<CodeBuilder> forwardingMethod(MethodType methodType) {
616         return new Consumer<>() {
617             @Override
618             public void accept(CodeBuilder cob) {
619                 if (implKind == MethodHandleInfo.REF_newInvokeSpecial) {
620                     cob.new_(implMethodClassDesc)
621                        .dup();
622                 }
623                 if (useImplMethodHandle) {
624                     ConstantPoolBuilder cp = cob.constantPool();
625                     cob.ldc(cp.constantDynamicEntry(cp.bsmEntry(cp.methodHandleEntry(BSM_CLASS_DATA_AT), List.of(cp.intEntry(0))),
626                                                     cp.nameAndTypeEntry(DEFAULT_NAME, CD_MethodHandle)));
627                 }
628                 for (int i = 0; i < argNames.length ; i++) {
629                     cob.aload(0)
630                        .getfield(pool.fieldRefEntry(lambdaClassEntry, pool.nameAndTypeEntry(argNames[i], argDescs[i])));
631                 }
632 
633                 convertArgumentTypes(cob, methodType);
634 
635                 if (useImplMethodHandle) {
636                     MethodType mtype = implInfo.getMethodType();
637                     if (implKind != MethodHandleInfo.REF_invokeStatic) {
638                         mtype = mtype.insertParameterTypes(0, implClass);
639                     }
640                     cob.invokevirtual(CD_MethodHandle, "invokeExact", methodDesc(mtype));
641                 } else {
642                     // Invoke the method we want to forward to
643                     cob.invoke(invocationOpcode(), implMethodClassDesc, implMethodName, implMethodDesc, implClass.isInterface());
644                 }
645                 // Convert the return value (if any) and return it
646                 // Note: if adapting from non-void to void, the 'return'
647                 // instruction will pop the unneeded result
648                 Class<?> implReturnClass = implMethodType.returnType();
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