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

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  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 
 48 import static java.lang.classfile.ClassFile.*;
 49 import java.lang.classfile.attribute.ExceptionsAttribute;
 50 import java.lang.classfile.constantpool.ClassEntry;
 51 import java.lang.classfile.constantpool.ConstantPoolBuilder;
 52 
 53 import static java.lang.constant.ConstantDescs.*;
 54 import static java.lang.invoke.MethodHandleNatives.Constants.NESTMATE_CLASS;
 55 import static java.lang.invoke.MethodHandleNatives.Constants.STRONG_LOADER_LINK;
 56 import jdk.internal.constant.ConstantUtils;
 57 import jdk.internal.constant.MethodTypeDescImpl;
 58 import jdk.internal.vm.annotation.Stable;
 59 import sun.invoke.util.Wrapper;
 60 
 61 /**
 62  * Lambda metafactory implementation which dynamically creates an
 63  * inner-class-like class per lambda callsite.
 64  *
 65  * @see LambdaMetafactory
 66  */
 67 /* package */ final class InnerClassLambdaMetafactory extends AbstractValidatingLambdaMetafactory {
 68     private static final String LAMBDA_INSTANCE_FIELD = "LAMBDA_INSTANCE$";
 69     private static final @Stable String[] ARG_NAME_CACHE = {"arg$1", "arg$2", "arg$3", "arg$4", "arg$5", "arg$6", "arg$7", "arg$8"};
 70     private static final ClassDesc[] EMPTY_CLASSDESC_ARRAY = ConstantUtils.EMPTY_CLASSDESC;
 71 








 72     // For dumping generated classes to disk, for debugging purposes
 73     private static final ClassFileDumper lambdaProxyClassFileDumper;
 74 
 75     private static final boolean disableEagerInitialization;
 76 




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

125      *                          substituted with their instantiation from
126      *                          the capture site
127      * @param isSerializable Should the lambda be made serializable?  If set,
128      *                       either the target type or one of the additional SAM
129      *                       types must extend {@code Serializable}.
130      * @param altInterfaces Additional interfaces which the lambda object
131      *                      should implement.
132      * @param altMethods Method types for additional signatures to be
133      *                   implemented by invoking the implementation method
134      * @throws LambdaConversionException If any of the meta-factory protocol
135      *         invariants are violated
136      */
137     public InnerClassLambdaMetafactory(MethodHandles.Lookup caller,
138                                        MethodType factoryType,
139                                        String interfaceMethodName,
140                                        MethodType interfaceMethodType,
141                                        MethodHandle implementation,
142                                        MethodType dynamicMethodType,
143                                        boolean isSerializable,
144                                        Class<?>[] altInterfaces,
145                                        MethodType[] altMethods)

146             throws LambdaConversionException {
147         super(caller, factoryType, interfaceMethodName, interfaceMethodType,
148               implementation, dynamicMethodType,
149               isSerializable, altInterfaces, altMethods);
150         implMethodClassDesc = implClassDesc(implClass);
151         implMethodName = implInfo.getName();
152         implMethodDesc = methodDesc(implInfo.getMethodType());
153         constructorType = factoryType.changeReturnType(Void.TYPE);
154         lambdaClassName = lambdaClassName(targetClass);
155         lambdaClassEntry = pool.classEntry(ConstantUtils.internalNameToDesc(lambdaClassName));
156         // If the target class invokes a protected method inherited from a
157         // superclass in a different package, or does 'invokespecial', the
158         // lambda class has no access to the resolved method, or does
159         // 'invokestatic' on a hidden class which cannot be resolved by name.
160         // Instead, we need to pass the live implementation method handle to
161         // the proxy class to invoke directly. (javac prefers to avoid this
162         // situation by generating bridges in the target class)
163         useImplMethodHandle = (Modifier.isProtected(implInfo.getModifiers()) &&
164                                !VerifyAccess.isSamePackage(targetClass, implInfo.getDeclaringClass())) ||
165                                implKind == MethodHandleInfo.REF_invokeSpecial ||
166                                implKind == MethodHandleInfo.REF_invokeStatic && implClass.isHidden();
167         int parameterCount = factoryType.parameterCount();
168         ClassDesc[] argDescs;
169         MethodTypeDesc constructorTypeDesc;

300             // Assure no duplicate interfaces (ClassFormatError)
301             Set<ClassDesc> itfs = LinkedHashSet.newLinkedHashSet(altInterfaces.length + 1);
302             itfs.add(interfaceDesc);
303             for (Class<?> i : altInterfaces) {
304                 itfs.add(classDesc(i));
305                 accidentallySerializable |= !isSerializable && Serializable.class.isAssignableFrom(i);
306             }
307             interfaces = List.copyOf(itfs);
308         }
309         final boolean finalAccidentallySerializable = accidentallySerializable;
310         final byte[] classBytes = ClassFile.of().build(lambdaClassEntry, pool, new Consumer<ClassBuilder>() {
311             @Override
312             public void accept(ClassBuilder clb) {
313                 clb.withFlags(ACC_SUPER | ACC_FINAL | ACC_SYNTHETIC)
314                    .withInterfaceSymbols(interfaces);
315                 // Generate final fields to be filled in by constructor
316                 for (int i = 0; i < argDescs.length; i++) {
317                     clb.withField(argName(i), argDescs[i], ACC_PRIVATE | ACC_FINAL);
318                 }
319 








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




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







354             return caller.makeHiddenClassDefiner(lambdaClassName, classBytes, lambdaProxyClassFileDumper, NESTMATE_CLASS | STRONG_LOADER_LINK)
355                          .defineClass(!disableEagerInitialization, classdata);
356 
357         } catch (Throwable t) {
358             throw new InternalError(t);
359         }
360     }
361 
362     /**
363      * Generate a static field and a static initializer that sets this field to an instance of the lambda
364      */
365     private void generateClassInitializer(ClassBuilder clb) {
366         ClassDesc lambdaTypeDescriptor = classDesc(factoryType.returnType());
367 
368         // Generate the static final field that holds the lambda singleton
369         clb.withField(LAMBDA_INSTANCE_FIELD, lambdaTypeDescriptor, ACC_PRIVATE | ACC_STATIC | ACC_FINAL);
370 
371         // Instantiate the lambda and store it to the static final field
372         clb.withMethodBody(CLASS_INIT_NAME, MTD_void, ACC_STATIC, new Consumer<>() {
373             @Override
374             public void accept(CodeBuilder cob) {
375                 assert factoryType.parameterCount() == 0;
376                 cob.new_(lambdaClassEntry)
377                    .dup()
378                    .invokespecial(pool.methodRefEntry(lambdaClassEntry, pool.nameAndTypeEntry(INIT_NAME, constructorTypeDesc)))
379                    .putstatic(pool.fieldRefEntry(lambdaClassEntry, pool.nameAndTypeEntry(LAMBDA_INSTANCE_FIELD, lambdaTypeDescriptor)))
380                    .return_();




381             }
382         });
383     }
384 
385     /**
386      * Generate the constructor for the class
387      */
388     private void generateConstructor(ClassBuilder clb) {
389         // Generate constructor
390         clb.withMethodBody(INIT_NAME, constructorTypeDesc, ACC_PRIVATE,
391                 new Consumer<>() {
392                     @Override
393                     public void accept(CodeBuilder cob) {
394                         cob.aload(0)
395                            .invokespecial(CD_Object, INIT_NAME, MTD_void);
396                         int parameterCount = factoryType.parameterCount();
397                         for (int i = 0; i < parameterCount; i++) {
398                             cob.aload(0)
399                                .loadLocal(TypeKind.from(factoryType.parameterType(i)), cob.parameterSlot(i))
400                                .putfield(pool.fieldRefEntry(lambdaClassEntry, pool.nameAndTypeEntry(argName(i), argDescs[i])));

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(argName(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 < argDescs.length; i++) {
510                     cob.aload(0)
511                        .getfield(pool.fieldRefEntry(lambdaClassEntry, pool.nameAndTypeEntry(argName(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

  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.access.JavaLangInvokeAccess.ReflectableLambdaInfo;
 29 import jdk.internal.constant.ClassOrInterfaceDescImpl;
 30 import jdk.internal.misc.CDS;
 31 import jdk.internal.util.ClassFileDumper;
 32 import sun.invoke.util.VerifyAccess;
 33 
 34 import java.io.Serializable;
 35 import java.lang.classfile.ClassBuilder;
 36 import java.lang.classfile.ClassFile;
 37 import java.lang.classfile.CodeBuilder;
 38 import java.lang.classfile.Label;
 39 import java.lang.classfile.MethodBuilder;
 40 import java.lang.classfile.Opcode;
 41 import java.lang.classfile.TypeKind;
 42 import java.lang.classfile.constantpool.MethodHandleEntry;
 43 import java.lang.classfile.constantpool.NameAndTypeEntry;
 44 import java.lang.constant.ClassDesc;
 45 import java.lang.constant.MethodTypeDesc;
 46 import java.lang.reflect.Modifier;
 47 import java.util.LinkedHashSet;
 48 import java.util.List;
 49 import java.util.Set;
 50 import java.util.function.Consumer;
 51 
 52 import static java.lang.classfile.ClassFile.*;
 53 import java.lang.classfile.attribute.ExceptionsAttribute;
 54 import java.lang.classfile.constantpool.ClassEntry;
 55 import java.lang.classfile.constantpool.ConstantPoolBuilder;
 56 
 57 import static java.lang.constant.ConstantDescs.*;
 58 import static java.lang.invoke.MethodHandleNatives.Constants.NESTMATE_CLASS;
 59 import static java.lang.invoke.MethodHandleNatives.Constants.STRONG_LOADER_LINK;
 60 import jdk.internal.constant.ConstantUtils;
 61 import jdk.internal.constant.MethodTypeDescImpl;
 62 import jdk.internal.vm.annotation.Stable;
 63 import sun.invoke.util.Wrapper;
 64 
 65 /**
 66  * Lambda metafactory implementation which dynamically creates an
 67  * inner-class-like class per lambda callsite.
 68  *
 69  * @see LambdaMetafactory
 70  */
 71 /* package */ final class InnerClassLambdaMetafactory extends AbstractValidatingLambdaMetafactory {
 72     private static final String LAMBDA_INSTANCE_FIELD = "LAMBDA_INSTANCE$";
 73     private static final @Stable String[] ARG_NAME_CACHE = {"arg$1", "arg$2", "arg$3", "arg$4", "arg$5", "arg$6", "arg$7", "arg$8"};
 74     private static final ClassDesc[] EMPTY_CLASSDESC_ARRAY = ConstantUtils.EMPTY_CLASSDESC;
 75 
 76     // Static builders to avoid lambdas
 77     record MethodBody(Consumer<CodeBuilder> code) implements Consumer<MethodBuilder> {
 78         @Override
 79         public void accept(MethodBuilder mb) {
 80             mb.withCode(code);
 81         }
 82     };
 83 
 84     // For dumping generated classes to disk, for debugging purposes
 85     private static final ClassFileDumper lambdaProxyClassFileDumper;
 86 
 87     private static final boolean disableEagerInitialization;
 88 
 89     private static final String NAME_METHOD_QUOTED = "__internal_quoted";
 90     private static final String QUOTED_FIELD_NAME = "quoted";
 91     private static final String MODEL_FIELD_NAME = "model";
 92 
 93     static {
 94         // To dump the lambda proxy classes, set this system property:
 95         //    -Djdk.invoke.LambdaMetafactory.dumpProxyClassFiles
 96         // or -Djdk.invoke.LambdaMetafactory.dumpProxyClassFiles=true
 97         final String dumpProxyClassesKey = "jdk.invoke.LambdaMetafactory.dumpProxyClassFiles";
 98         lambdaProxyClassFileDumper = ClassFileDumper.getInstance(dumpProxyClassesKey, "DUMP_LAMBDA_PROXY_CLASS_FILES");
 99 
100         final String disableEagerInitializationKey = "jdk.internal.lambda.disableEagerInitialization";
101         disableEagerInitialization = Boolean.getBoolean(disableEagerInitializationKey);
102     }
103 
104     // See context values in AbstractValidatingLambdaMetafactory
105     private final ClassDesc implMethodClassDesc;     // Name of type containing implementation "CC"
106     private final String implMethodName;             // Name of implementation method "impl"
107     private final MethodTypeDesc implMethodDesc;     // Type descriptor for implementation methods "(I)Ljava/lang/String;"
108     private final MethodType constructorType;        // Generated class constructor type "(CC)void"
109     private final MethodTypeDesc constructorTypeDesc;// Type descriptor for the generated class constructor type "(CC)void"
110     private final ClassDesc[] argDescs;              // Type descriptors for the constructor arguments
111     private final String lambdaClassName;            // Generated name for the generated class "X$$Lambda$1"
112     private final ConstantPoolBuilder pool = ConstantPoolBuilder.of();

141      *                          substituted with their instantiation from
142      *                          the capture site
143      * @param isSerializable Should the lambda be made serializable?  If set,
144      *                       either the target type or one of the additional SAM
145      *                       types must extend {@code Serializable}.
146      * @param altInterfaces Additional interfaces which the lambda object
147      *                      should implement.
148      * @param altMethods Method types for additional signatures to be
149      *                   implemented by invoking the implementation method
150      * @throws LambdaConversionException If any of the meta-factory protocol
151      *         invariants are violated
152      */
153     public InnerClassLambdaMetafactory(MethodHandles.Lookup caller,
154                                        MethodType factoryType,
155                                        String interfaceMethodName,
156                                        MethodType interfaceMethodType,
157                                        MethodHandle implementation,
158                                        MethodType dynamicMethodType,
159                                        boolean isSerializable,
160                                        Class<?>[] altInterfaces,
161                                        MethodType[] altMethods,
162                                        ReflectableLambdaInfo reflectableLambdaInfo)
163             throws LambdaConversionException {
164         super(caller, factoryType, interfaceMethodName, interfaceMethodType,
165               implementation, dynamicMethodType,
166               isSerializable, altInterfaces, altMethods, reflectableLambdaInfo);
167         implMethodClassDesc = implClassDesc(implClass);
168         implMethodName = implInfo.getName();
169         implMethodDesc = methodDesc(implInfo.getMethodType());
170         constructorType = factoryType.changeReturnType(Void.TYPE);
171         lambdaClassName = lambdaClassName(targetClass);
172         lambdaClassEntry = pool.classEntry(ConstantUtils.internalNameToDesc(lambdaClassName));
173         // If the target class invokes a protected method inherited from a
174         // superclass in a different package, or does 'invokespecial', the
175         // lambda class has no access to the resolved method, or does
176         // 'invokestatic' on a hidden class which cannot be resolved by name.
177         // Instead, we need to pass the live implementation method handle to
178         // the proxy class to invoke directly. (javac prefers to avoid this
179         // situation by generating bridges in the target class)
180         useImplMethodHandle = (Modifier.isProtected(implInfo.getModifiers()) &&
181                                !VerifyAccess.isSamePackage(targetClass, implInfo.getDeclaringClass())) ||
182                                implKind == MethodHandleInfo.REF_invokeSpecial ||
183                                implKind == MethodHandleInfo.REF_invokeStatic && implClass.isHidden();
184         int parameterCount = factoryType.parameterCount();
185         ClassDesc[] argDescs;
186         MethodTypeDesc constructorTypeDesc;

317             // Assure no duplicate interfaces (ClassFormatError)
318             Set<ClassDesc> itfs = LinkedHashSet.newLinkedHashSet(altInterfaces.length + 1);
319             itfs.add(interfaceDesc);
320             for (Class<?> i : altInterfaces) {
321                 itfs.add(classDesc(i));
322                 accidentallySerializable |= !isSerializable && Serializable.class.isAssignableFrom(i);
323             }
324             interfaces = List.copyOf(itfs);
325         }
326         final boolean finalAccidentallySerializable = accidentallySerializable;
327         final byte[] classBytes = ClassFile.of().build(lambdaClassEntry, pool, new Consumer<ClassBuilder>() {
328             @Override
329             public void accept(ClassBuilder clb) {
330                 clb.withFlags(ACC_SUPER | ACC_FINAL | ACC_SYNTHETIC)
331                    .withInterfaceSymbols(interfaces);
332                 // Generate final fields to be filled in by constructor
333                 for (int i = 0; i < argDescs.length; i++) {
334                     clb.withField(argName(i), argDescs[i], ACC_PRIVATE | ACC_FINAL);
335                 }
336 
337                 if (reflectableLambdaInfo != null) {
338                     // the field that will hold the quoted instance
339                     clb.withField(QUOTED_FIELD_NAME, reflectableLambdaInfo.quotedClass(), ACC_PRIVATE);
340                     // the field that will hold the model
341                     clb.withField(MODEL_FIELD_NAME, reflectableLambdaInfo.funcOpClass(),
342                             ACC_PRIVATE | ACC_STATIC);
343                 }
344 
345                 generateConstructor(clb);
346 
347                 generateClassInitializationMethod(clb);
348 

349 
350                 // Forward the SAM method
351                 clb.withMethodBody(interfaceMethodName,
352                         methodDesc(interfaceMethodType),
353                         ACC_PUBLIC,
354                         forwardingMethod(interfaceMethodType));
355 
356                 // Forward the bridges
357                 if (altMethods != null) {
358                     for (MethodType mt : altMethods) {
359                         clb.withMethodBody(interfaceMethodName,
360                                 methodDesc(mt),
361                                 ACC_PUBLIC | ACC_BRIDGE,
362                                 forwardingMethod(mt));
363                     }
364                 }
365 
366                 if (isSerializable)
367                     generateSerializationFriendlyMethods(clb);
368                 else if (finalAccidentallySerializable)
369                     generateSerializationHostileMethods(clb);
370 
371                 if (reflectableLambdaInfo != null) {
372                     generateQuotedMethod(clb);
373                 }
374             }
375         });
376 
377         // Define the generated class in this VM.
378 
379         try {
380             // this class is linked at the indy callsite; so define a hidden nestmate
381             List<?> classdata;
382             if (useImplMethodHandle || reflectableLambdaInfo != null) {
383                 classdata = reflectableLambdaInfo == null ?
384                         List.of(implementation) :
385                         List.of(implementation, reflectableLambdaInfo.opHandle(), reflectableLambdaInfo.extractOpHandle());
386             } else {
387                 classdata = null;
388             }
389             return caller.makeHiddenClassDefiner(lambdaClassName, classBytes, lambdaProxyClassFileDumper, NESTMATE_CLASS | STRONG_LOADER_LINK)
390                          .defineClass(!disableEagerInitialization, classdata);
391 
392         } catch (Throwable t) {
393             throw new InternalError(t);
394         }
395     }
396 
397     private void generateClassInitializationMethod(ClassBuilder clb) {
398         if (!(factoryType.parameterCount() == 0 && disableEagerInitialization) && reflectableLambdaInfo == null) {
399             return;
400         }
401         clb.withMethodBody(CLASS_INIT_NAME, MTD_void, ACC_STATIC, new Consumer<CodeBuilder>() {






402             @Override
403             public void accept(CodeBuilder cob) {
404                 if (factoryType.parameterCount() == 0 && disableEagerInitialization) {
405                     ClassDesc lambdaTypeDescriptor = classDesc(factoryType.returnType());
406                     // Generate the static final field that holds the lambda singleton
407                     clb.withField(LAMBDA_INSTANCE_FIELD, lambdaTypeDescriptor, ACC_PRIVATE | ACC_STATIC | ACC_FINAL);
408                     cob.new_(lambdaClassEntry)
409                             .dup()
410                             .invokespecial(pool.methodRefEntry(lambdaClassEntry, pool.nameAndTypeEntry(INIT_NAME, constructorTypeDesc)))
411                             .putstatic(pool.fieldRefEntry(lambdaClassEntry, pool.nameAndTypeEntry(LAMBDA_INSTANCE_FIELD, lambdaTypeDescriptor)));
412                 }
413                 cob.return_();
414             }
415         });
416     }
417 
418     /**
419      * Generate the constructor for the class
420      */
421     private void generateConstructor(ClassBuilder clb) {
422         // Generate constructor
423         clb.withMethodBody(INIT_NAME, constructorTypeDesc, ACC_PRIVATE,
424                 new Consumer<>() {
425                     @Override
426                     public void accept(CodeBuilder cob) {
427                         cob.aload(0)
428                            .invokespecial(CD_Object, INIT_NAME, MTD_void);
429                         int parameterCount = factoryType.parameterCount();
430                         for (int i = 0; i < parameterCount; i++) {
431                             cob.aload(0)
432                                .loadLocal(TypeKind.from(factoryType.parameterType(i)), cob.parameterSlot(i))
433                                .putfield(pool.fieldRefEntry(lambdaClassEntry, pool.nameAndTypeEntry(argName(i), argDescs[i])));

476                            .ldc(implInfo.getName())
477                            .ldc(implInfo.getMethodType().toMethodDescriptorString())
478                            .ldc(dynamicMethodType.toMethodDescriptorString())
479                            .loadConstant(argDescs.length)
480                            .anewarray(CD_Object);
481                         for (int i = 0; i < argDescs.length; i++) {
482                             cob.dup()
483                                .loadConstant(i)
484                                .aload(0)
485                                .getfield(pool.fieldRefEntry(lambdaClassEntry, pool.nameAndTypeEntry(argName(i), argDescs[i])));
486                             TypeConvertingMethodAdapter.boxIfTypePrimitive(cob, TypeKind.from(argDescs[i]));
487                             cob.aastore();
488                         }
489                         cob.invokespecial(SerializationSupport.CD_SerializedLambda, INIT_NAME,
490                                           SerializationSupport.MTD_CTOR_SERIALIZED_LAMBDA)
491                            .areturn();
492                     }
493                 });
494     }
495 
496     /**
497     * Generate method #__internal_quoted()
498      */
499     private void generateQuotedMethod(ClassBuilder clb) {
500         clb.withMethod(NAME_METHOD_QUOTED, MethodTypeDesc.of(reflectableLambdaInfo.quotedClass()), ACC_PRIVATE, new MethodBody(new Consumer<CodeBuilder>() {
501             @Override
502             public void accept(CodeBuilder cob) {
503                 cob.aload(0)
504                         .invokevirtual(lambdaClassEntry.asSymbol(), "getQuoted", MethodTypeDesc.of(reflectableLambdaInfo.quotedClass()))
505                         .areturn();
506             }
507         }));
508         // generate helper methods
509         /*
510         synchronized Quoted getQuoted() {
511             Quoted v = quoted;
512             if (v == null) {
513                 v = quoted = Quoted.extractOp(getModel(), captures);
514             }
515             return v;
516         }
517         * */
518         clb.withMethod("getQuoted", MethodTypeDesc.of(reflectableLambdaInfo.quotedClass()),
519                 ACC_PRIVATE + ACC_SYNCHRONIZED,
520                 new MethodBody(new Consumer<CodeBuilder>() {
521                     @Override
522                     public void accept(CodeBuilder cob) {
523                         cob.aload(0)
524                                 .getfield(lambdaClassEntry.asSymbol(), QUOTED_FIELD_NAME, reflectableLambdaInfo.quotedClass())
525                                 .astore(1)
526                                 .aload(1)
527                                 .ifThen(Opcode.IFNULL, bcb -> {
528                                     bcb.aload(0); // will be used by putfield
529 
530                                     // load class data: MH to Quoted.extractOp
531                                     ConstantPoolBuilder cp = bcb.constantPool();
532                                     MethodHandleEntry bsmDataAt = cp.methodHandleEntry(BSM_CLASS_DATA_AT);
533                                     NameAndTypeEntry natMH = cp.nameAndTypeEntry(DEFAULT_NAME, CD_MethodHandle);
534                                     bcb.ldc(cp.constantDynamicEntry(cp.bsmEntry(bsmDataAt, List.of(cp.intEntry(2))), natMH));
535 
536                                     bcb.invokestatic(lambdaClassEntry.asSymbol(), "getModel", MethodTypeDesc.of(reflectableLambdaInfo.funcOpClass()));
537 
538                                     // load captured args in array
539                                     int capturedArity = factoryType.parameterCount();
540                                     bcb.loadConstant(capturedArity)
541                                             .anewarray(CD_Object);
542                                     for (int i = 0; i < capturedArity; i++) {
543                                         bcb.dup()
544                                                 .loadConstant(i)
545                                                 .aload(0)
546                                                 .getfield(lambdaClassEntry.asSymbol(), argName(i), argDescs[i]);
547                                         TypeConvertingMethodAdapter.boxIfTypePrimitive(bcb, TypeKind.from(argDescs[i]));
548                                         bcb.aastore();
549                                     }
550 
551                                     // invoke Quoted.extractOp
552                                     bcb.invokevirtual(CD_MethodHandle, "invokeExact", methodDesc(reflectableLambdaInfo.extractOpHandle().type()))
553                                             .dup_x1()
554                                             .putfield(lambdaClassEntry.asSymbol(), QUOTED_FIELD_NAME, reflectableLambdaInfo.quotedClass())
555                                             .astore(1);
556 
557                                 })
558                                 .aload(1)
559                                 .areturn();
560                     }
561                 }));
562 
563         /*
564         private static synchronized CoreOp.FuncOp getModel() {
565             FuncOp v = model;
566             if (v == null) {
567                 v = model = ...invoke lambda op building method...
568             }
569             return v;
570         }
571         * */
572         clb.withMethod("getModel", MethodTypeDesc.of(reflectableLambdaInfo.funcOpClass()),
573                 ACC_PRIVATE + ACC_STATIC + ACC_SYNCHRONIZED,
574                 new MethodBody(new Consumer<CodeBuilder>() {
575                     @Override
576                     public void accept(CodeBuilder cob) {
577                         ClassDesc funcOpClassDesc = reflectableLambdaInfo.funcOpClass();
578                         cob.getstatic(lambdaClassEntry.asSymbol(), MODEL_FIELD_NAME, funcOpClassDesc)
579                                 .astore(0)
580                                 .aload(0)
581                                 .ifThen(Opcode.IFNULL, bcb -> {
582                                     // load class data: MH to op building method
583                                     ConstantPoolBuilder cp = pool;
584                                     MethodHandleEntry bsmDataAt = cp.methodHandleEntry(BSM_CLASS_DATA_AT);
585                                     NameAndTypeEntry natMH = cp.nameAndTypeEntry(DEFAULT_NAME, CD_MethodHandle);
586                                     cob.ldc(cp.constantDynamicEntry(cp.bsmEntry(bsmDataAt, List.of(cp.intEntry(1))), natMH));
587                                     MethodType mtype = quotableOpGetterInfo.getMethodType();
588                                     cob.invokevirtual(CD_MethodHandle, "invokeExact", mtype.describeConstable().get())
589                                             .checkcast(funcOpClassDesc)
590                                             .dup()
591                                             .putstatic(lambdaClassEntry.asSymbol(), MODEL_FIELD_NAME, funcOpClassDesc)
592                                             .astore(0);
593                                 })
594                                 .aload(0)
595                                 .areturn();
596                     }
597                 }));
598     }
599 
600     /**
601      * Generate a readObject/writeObject method that is hostile to serialization
602      */
603     private void generateSerializationHostileMethods(ClassBuilder clb) {
604         var hostileMethod = new Consumer<MethodBuilder>() {
605             @Override
606             public void accept(MethodBuilder mb) {
607                 ConstantPoolBuilder cp = mb.constantPool();
608                 ClassEntry nseCE = cp.classEntry(SerializationSupport.CD_NotSerializableException);
609                 mb.with(ExceptionsAttribute.of(nseCE))
610                         .withCode(new Consumer<CodeBuilder>() {
611                             @Override
612                             public void accept(CodeBuilder cob) {
613                                 cob.new_(nseCE)
614                                         .dup()
615                                         .ldc("Non-serializable lambda")
616                                         .invokespecial(cp.methodRefEntry(nseCE, cp.nameAndTypeEntry(INIT_NAME,
617                                                 SerializationSupport.MTD_CTOR_NOT_SERIALIZABLE_EXCEPTION)))
618                                         .athrow();
619                             }

623         clb.withMethod(SerializationSupport.NAME_METHOD_WRITE_OBJECT, SerializationSupport.MTD_void_ObjectOutputStream,
624                 ACC_PRIVATE + ACC_FINAL, hostileMethod);
625         clb.withMethod(SerializationSupport.NAME_METHOD_READ_OBJECT, SerializationSupport.MTD_void_ObjectInputStream,
626                 ACC_PRIVATE + ACC_FINAL, hostileMethod);
627     }
628 
629     /**
630      * This method generates a method body which calls the lambda implementation
631      * method, converting arguments, as needed.
632      */
633     Consumer<CodeBuilder> forwardingMethod(MethodType methodType) {
634         return new Consumer<>() {
635             @Override
636             public void accept(CodeBuilder cob) {
637                 if (implKind == MethodHandleInfo.REF_newInvokeSpecial) {
638                     cob.new_(implMethodClassDesc)
639                        .dup();
640                 }
641                 if (useImplMethodHandle) {
642                     ConstantPoolBuilder cp = cob.constantPool();
643                     cob.ldc(cp.constantDynamicEntry(cp.bsmEntry(cp.methodHandleEntry(BSM_CLASS_DATA_AT), List.of(cp.intEntry(0))),
644                                                     cp.nameAndTypeEntry(DEFAULT_NAME, CD_MethodHandle)));
645                 }
646                 for (int i = 0; i < argDescs.length; i++) {
647                     cob.aload(0)
648                        .getfield(pool.fieldRefEntry(lambdaClassEntry, pool.nameAndTypeEntry(argName(i), argDescs[i])));
649                 }
650 
651                 convertArgumentTypes(cob, methodType);
652 
653                 if (useImplMethodHandle) {
654                     MethodType mtype = implInfo.getMethodType();
655                     if (implKind != MethodHandleInfo.REF_invokeStatic) {
656                         mtype = mtype.insertParameterTypes(0, implClass);
657                     }
658                     cob.invokevirtual(CD_MethodHandle, "invokeExact", methodDesc(mtype));
659                 } else {
660                     // Invoke the method we want to forward to
661                     cob.invoke(invocationOpcode(), implMethodClassDesc, implMethodName, implMethodDesc, implClass.isInterface());
662                 }
663                 // Convert the return value (if any) and return it
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