< prev index next >

src/java.base/share/classes/java/lang/runtime/SwitchBootstraps.java

Print this page

719               .with(StackMapTableAttribute.of(stackMapFrames));
720             DirectCodeBuilder.withMaxs(cb, 3, locals.size()); // enum labels use 3 stack, others use 2
721         };
722     }
723 
724     private static boolean isNotValidPair(Class<?> selectorType, Object caseLabel) {
725         return (selectorType == boolean.class && caseLabel != boolean.class && caseLabel != Boolean.class) ||
726                (selectorType != boolean.class && selectorType.isPrimitive() && (caseLabel == boolean.class || caseLabel == Boolean.class));
727     }
728 
729     /*
730      * Construct the method handle that represents the method int typeSwitch(Object, int, BiPredicate, List)
731      */
732     private static MethodHandle generateTypeSwitch(MethodHandles.Lookup caller, Class<?> selectorType, Object[] labelConstants) {
733         boolean addExtraInfo = needsExtraInfo(selectorType, labelConstants);
734         List<EnumDesc<?>> enumDescs = addExtraInfo ? new ArrayList<>() : null;
735         List<Class<?>> extraClassLabels = addExtraInfo ? new ArrayList<>() : null;
736 
737         byte[] classBytes = ClassFile.of(ClassFile.StackMapsOption.DROP_STACK_MAPS).build(ConstantUtils.binaryNameToDesc(typeSwitchClassName(caller.lookupClass())),
738                 clb -> {
739                     clb.withFlags(AccessFlag.FINAL, AccessFlag.SUPER, AccessFlag.SYNTHETIC)
740                        .withMethodBody("typeSwitch",
741                                        addExtraInfo ? MTD_TYPE_SWITCH_EXTRA : MTD_TYPE_SWITCH,
742                                        ClassFile.ACC_FINAL | ClassFile.ACC_PUBLIC | ClassFile.ACC_STATIC,
743                                        generateTypeSwitchSkeleton(selectorType, labelConstants, enumDescs, extraClassLabels));
744         });
745 
746         try {
747             // this class is linked at the indy callsite; so define a hidden nestmate
748             MethodHandles.Lookup lookup;
749             lookup = caller.defineHiddenClass(classBytes, true, NESTMATE, STRONG);
750             MethodHandle typeSwitch = lookup.findStatic(lookup.lookupClass(),
751                                                         "typeSwitch",
752                                                         addExtraInfo ? MT_TYPE_SWITCH_EXTRA : MT_TYPE_SWITCH);
753             if (addExtraInfo) {
754                 typeSwitch = MethodHandles.insertArguments(typeSwitch, 2, new ResolvedEnumLabels(caller, enumDescs.toArray(new EnumDesc<?>[0])),
755                         List.copyOf(extraClassLabels));
756             }
757             return typeSwitch;
758         } catch (Throwable t) {
759             throw new IllegalArgumentException(t);

719               .with(StackMapTableAttribute.of(stackMapFrames));
720             DirectCodeBuilder.withMaxs(cb, 3, locals.size()); // enum labels use 3 stack, others use 2
721         };
722     }
723 
724     private static boolean isNotValidPair(Class<?> selectorType, Object caseLabel) {
725         return (selectorType == boolean.class && caseLabel != boolean.class && caseLabel != Boolean.class) ||
726                (selectorType != boolean.class && selectorType.isPrimitive() && (caseLabel == boolean.class || caseLabel == Boolean.class));
727     }
728 
729     /*
730      * Construct the method handle that represents the method int typeSwitch(Object, int, BiPredicate, List)
731      */
732     private static MethodHandle generateTypeSwitch(MethodHandles.Lookup caller, Class<?> selectorType, Object[] labelConstants) {
733         boolean addExtraInfo = needsExtraInfo(selectorType, labelConstants);
734         List<EnumDesc<?>> enumDescs = addExtraInfo ? new ArrayList<>() : null;
735         List<Class<?>> extraClassLabels = addExtraInfo ? new ArrayList<>() : null;
736 
737         byte[] classBytes = ClassFile.of(ClassFile.StackMapsOption.DROP_STACK_MAPS).build(ConstantUtils.binaryNameToDesc(typeSwitchClassName(caller.lookupClass())),
738                 clb -> {
739                     clb.withFlags(AccessFlag.FINAL, (PreviewFeatures.isEnabled())  ? AccessFlag.IDENTITY : AccessFlag.SUPER, AccessFlag.SYNTHETIC)
740                        .withMethodBody("typeSwitch",
741                                        addExtraInfo ? MTD_TYPE_SWITCH_EXTRA : MTD_TYPE_SWITCH,
742                                        ClassFile.ACC_FINAL | ClassFile.ACC_PUBLIC | ClassFile.ACC_STATIC,
743                                        generateTypeSwitchSkeleton(selectorType, labelConstants, enumDescs, extraClassLabels));
744         });
745 
746         try {
747             // this class is linked at the indy callsite; so define a hidden nestmate
748             MethodHandles.Lookup lookup;
749             lookup = caller.defineHiddenClass(classBytes, true, NESTMATE, STRONG);
750             MethodHandle typeSwitch = lookup.findStatic(lookup.lookupClass(),
751                                                         "typeSwitch",
752                                                         addExtraInfo ? MT_TYPE_SWITCH_EXTRA : MT_TYPE_SWITCH);
753             if (addExtraInfo) {
754                 typeSwitch = MethodHandles.insertArguments(typeSwitch, 2, new ResolvedEnumLabels(caller, enumDescs.toArray(new EnumDesc<?>[0])),
755                         List.copyOf(extraClassLabels));
756             }
757             return typeSwitch;
758         } catch (Throwable t) {
759             throw new IllegalArgumentException(t);
< prev index next >