private void validateClass(Class<?> source, ValidationProblemCollector problems) {
    int modifiers = source.getModifiers();

    if (Modifier.isInterface(modifiers)) {
      problems.add("Must be a class, not an interface");
    }

    if (source.getEnclosingClass() != null) {
      if (Modifier.isStatic(modifiers)) {
        if (Modifier.isPrivate(modifiers)) {
          problems.add("Class cannot be private");
        }
      } else {
        problems.add("Enclosed classes must be static and non private");
      }
    }

    Constructor<?>[] constructors = source.getDeclaredConstructors();
    for (Constructor<?> constructor : constructors) {
      if (constructor.getParameterTypes().length > 0) {
        problems.add("Cannot declare a constructor that takes arguments");
        break;
      }
    }

    Field[] fields = source.getDeclaredFields();
    for (Field field : fields) {
      int fieldModifiers = field.getModifiers();
      if (!field.isSynthetic()
          && !(Modifier.isStatic(fieldModifiers) && Modifier.isFinal(fieldModifiers))) {
        problems.add(field, "Fields must be static final.");
      }
    }
  }
  private void writeSetter(ClassVisitor visitor, Type generatedType, ModelProperty<?> property) {
    WeaklyTypeReferencingMethod<?, Void> weakSetter = property.getSetter();
    // There is no setter for this property
    if (weakSetter == null) {
      return;
    }

    String propertyName = property.getName();
    Class<?> propertyClass = property.getType().getConcreteClass();
    Type propertyType = Type.getType(propertyClass);
    Label calledOutsideOfConstructor = new Label();

    Method setter = weakSetter.getMethod();

    // the regular typed setter
    String methodDescriptor = Type.getMethodDescriptor(Type.VOID_TYPE, propertyType);
    MethodVisitor methodVisitor =
        declareMethod(
            visitor, setter.getName(), methodDescriptor, AsmClassGeneratorUtils.signature(setter));

    putCanCallSettersFieldValueOnStack(methodVisitor, generatedType);
    jumpToLabelIfStackEvaluatesToTrue(methodVisitor, calledOutsideOfConstructor);
    throwExceptionBecauseCalledOnItself(methodVisitor);

    methodVisitor.visitLabel(calledOutsideOfConstructor);
    putStateFieldValueOnStack(methodVisitor, generatedType);
    putConstantOnStack(methodVisitor, propertyName);
    putFirstMethodArgumentOnStack(methodVisitor, propertyType);
    if (propertyClass.isPrimitive()) {
      boxType(methodVisitor, propertyClass);
    }
    invokeStateSetMethod(methodVisitor);

    finishVisitingMethod(methodVisitor);
  }
  private <T> CachedRuleSource doExtract(final Class<T> source) {
    final ModelType<T> type = ModelType.of(source);
    DefaultMethodModelRuleExtractionContext context =
        new DefaultMethodModelRuleExtractionContext(type, this);

    // TODO - exceptions thrown here should point to some extensive documentation on the concept of
    // class rule sources

    StructSchema<T> schema = getSchema(source, context);
    if (schema == null) {
      throw new InvalidModelRuleDeclarationException(context.problems.format());
    }

    // sort for determinism
    Set<Method> methods = new TreeSet<Method>(Ordering.usingToString());
    methods.addAll(Arrays.asList(source.getDeclaredMethods()));

    ImmutableList.Builder<ModelProperty<?>> implicitInputs = ImmutableList.builder();
    ModelProperty<?> target = null;
    for (ModelProperty<?> property : schema.getProperties()) {
      if (property.isAnnotationPresent(RuleTarget.class)) {
        target = property;
      } else if (property.isAnnotationPresent(RuleInput.class)
          && !(property.getSchema() instanceof ScalarValueSchema)) {
        implicitInputs.add(property);
      }
      for (WeaklyTypeReferencingMethod<?, ?> method : property.getAccessors()) {
        methods.remove(method.getMethod());
      }
    }

    ImmutableList.Builder<ExtractedRuleDetails> rules = ImmutableList.builder();
    for (Method method : methods) {
      MethodRuleDefinition<?, ?> ruleDefinition =
          DefaultMethodRuleDefinition.create(source, method);
      ExtractedModelRule rule = getMethodHandler(ruleDefinition, method, context);
      if (rule != null) {
        rules.add(new ExtractedRuleDetails(ruleDefinition, rule));
      }
    }

    if (context.hasProblems()) {
      throw new InvalidModelRuleDeclarationException(context.problems.format());
    }

    StructBindings<T> bindings = structBindingsStore.getBindings(schema);

    if (schema.getProperties().isEmpty()) {
      return new StatelessRuleSource(
          rules.build(),
          Modifier.isAbstract(source.getModifiers())
              ? new AbstractRuleSourceFactory<T>(schema, bindings, proxyFactory)
              : new ConcreteRuleSourceFactory<T>(type));
    } else {
      return new ParameterizedRuleSource(
          rules.build(), target, implicitInputs.build(), schema, bindings, proxyFactory);
    }
  }
 @Override
 public T create() {
   Class<T> concreteClass = type.getConcreteClass();
   try {
     Constructor<T> declaredConstructor = concreteClass.getDeclaredConstructor();
     declaredConstructor.setAccessible(true);
     return declaredConstructor.newInstance();
   } catch (InvocationTargetException e) {
     throw UncheckedException.throwAsUncheckedException(e.getTargetException());
   } catch (Exception e) {
     throw UncheckedException.throwAsUncheckedException(e);
   }
 }
  // the overload of type Object for Groovy coercions:  public void setFoo(Object foo)
  private void createTypeConvertingSetter(
      ClassVisitor visitor, Type generatedType, ModelProperty<?> property) {
    if (!property.isWritable() || !(property.getSchema() instanceof ScalarValueSchema)) {
      return;
    }

    Class<?> propertyClass = property.getType().getConcreteClass();
    Type propertyType = Type.getType(propertyClass);
    Class<?> boxedClass =
        propertyClass.isPrimitive() ? BOXED_TYPES.get(propertyClass) : propertyClass;
    Type boxedType = Type.getType(boxedClass);

    Method setter = property.getSetter().getMethod();
    MethodVisitor methodVisitor =
        declareMethod(
            visitor,
            setter.getName(),
            SET_OBJECT_PROPERTY_DESCRIPTOR,
            SET_OBJECT_PROPERTY_DESCRIPTOR);

    putThisOnStack(methodVisitor);
    putTypeConverterFieldValueOnStack(methodVisitor, generatedType);

    // Object converted = $typeConverter.convert(foo, Float.class, false);
    methodVisitor.visitVarInsn(ALOAD, 1); // put var #1 ('foo') on the stack
    methodVisitor.visitLdcInsn(boxedType); // push the constant Class onto the stack
    methodVisitor.visitInsn(
        propertyClass.isPrimitive()
            ? ICONST_1
            : ICONST_0); // push int 1 or 0 (interpreted as true or false) onto the stack
    methodVisitor.visitMethodInsn(
        INVOKEINTERFACE,
        TYPE_CONVERTER_TYPE.getInternalName(),
        "convert",
        COERCE_TO_SCALAR_DESCRIPTOR,
        true);
    methodVisitor.visitTypeInsn(CHECKCAST, boxedType.getInternalName());

    if (propertyClass.isPrimitive()) {
      unboxType(methodVisitor, propertyClass);
    }

    // invoke the typed setter, popping 'this' and 'converted' from the stack
    methodVisitor.visitMethodInsn(
        INVOKEVIRTUAL,
        generatedType.getInternalName(),
        setter.getName(),
        Type.getMethodDescriptor(Type.VOID_TYPE, propertyType),
        false);
    finishVisitingMethod(methodVisitor);
  }
 private void castFirstStackElement(MethodVisitor methodVisitor, Class<?> returnType) {
   if (returnType.isPrimitive()) {
     unboxType(methodVisitor, returnType);
   } else {
     methodVisitor.visitTypeInsn(CHECKCAST, Type.getInternalName(returnType));
   }
 }
 private Method getToStringMethod(Class<?> managedTypeClass) {
   try {
     return managedTypeClass.getMethod("toString");
   } catch (NoSuchMethodException e) {
     return null;
   }
 }
  private void writeDelegateMethods(
      final ClassVisitor visitor,
      final Type generatedType,
      StructSchema<?> delegateSchema,
      Set<Class<?>> typesToDelegate) {
    Class<?> delegateClass = delegateSchema.getType().getConcreteClass();
    Type delegateType = Type.getType(delegateClass);
    Map<Equivalence.Wrapper<Method>, Map<Class<?>, Method>> methodsToDelegate = Maps.newHashMap();
    for (Class<?> typeToDelegate : typesToDelegate) {
      for (Method methodToDelegate : typeToDelegate.getMethods()) {
        if (ModelSchemaUtils.isIgnoredMethod(methodToDelegate)) {
          continue;
        }
        Equivalence.Wrapper<Method> methodKey = METHOD_EQUIVALENCE.wrap(methodToDelegate);
        Map<Class<?>, Method> methodsByReturnType = methodsToDelegate.get(methodKey);
        if (methodsByReturnType == null) {
          methodsByReturnType = Maps.newHashMap();
          methodsToDelegate.put(methodKey, methodsByReturnType);
        }
        methodsByReturnType.put(methodToDelegate.getReturnType(), methodToDelegate);
      }
    }
    Set<Equivalence.Wrapper<Method>> delegateMethodKeys =
        ImmutableSet.copyOf(
            Iterables.transform(
                Arrays.asList(delegateClass.getMethods()),
                new Function<Method, Equivalence.Wrapper<Method>>() {
                  @Override
                  public Equivalence.Wrapper<Method> apply(Method method) {
                    return METHOD_EQUIVALENCE.wrap(method);
                  }
                }));
    for (Map.Entry<Equivalence.Wrapper<Method>, Map<Class<?>, Method>> entry :
        methodsToDelegate.entrySet()) {
      Equivalence.Wrapper<Method> methodKey = entry.getKey();
      if (!delegateMethodKeys.contains(methodKey)) {
        continue;
      }

      Map<Class<?>, Method> methodsByReturnType = entry.getValue();
      for (Method methodToDelegate : methodsByReturnType.values()) {
        writeDelegatedMethod(visitor, generatedType, delegateType, methodToDelegate);
      }
    }
  }
  private <T> StructSchema<T> getSchema(
      Class<T> source, DefaultMethodModelRuleExtractionContext context) {
    if (!RuleSource.class.isAssignableFrom(source)
        || !source.getSuperclass().equals(RuleSource.class)) {
      context.add("Rule source classes must directly extend " + RuleSource.class.getName());
    }

    ModelSchema<T> schema = schemaStore.getSchema(source);
    if (!(schema instanceof StructSchema)) {
      return null;
    }

    validateClass(source, context);
    return (StructSchema<T>) schema;
  }
 private void unboxType(MethodVisitor methodVisitor, Class<?> primitiveClass) {
   // Float f = (Float) tmp
   // f==null?0:f.floatValue()
   Class<?> boxedType = BOXED_TYPES.get(primitiveClass);
   Type primitiveType = Type.getType(primitiveClass);
   methodVisitor.visitTypeInsn(CHECKCAST, Type.getInternalName(boxedType));
   methodVisitor.visitInsn(DUP);
   Label exit = new Label();
   Label elseValue = new Label();
   methodVisitor.visitJumpInsn(IFNONNULL, elseValue);
   methodVisitor.visitInsn(POP);
   pushDefaultValue(methodVisitor, primitiveClass);
   methodVisitor.visitJumpInsn(GOTO, exit);
   methodVisitor.visitLabel(elseValue);
   methodVisitor.visitMethodInsn(
       INVOKEVIRTUAL,
       Type.getInternalName(boxedType),
       primitiveClass.getSimpleName() + "Value",
       Type.getMethodDescriptor(primitiveType),
       false);
   methodVisitor.visitLabel(exit);
 }
 private static boolean isManagedCollection(ModelType<?> type) {
   Class<?> concreteClass = type.getConcreteClass();
   return concreteClass.equals(ModelMap.class) || concreteClass.equals(ModelSet.class);
 }
 private void putClassOnStack(MethodVisitor methodVisitor, Class<?> managedTypeClass) {
   putConstantOnStack(methodVisitor, managedTypeClass.getName());
   methodVisitor.visitMethodInsn(
       INVOKESTATIC, CLASS_INTERNAL_NAME, "forName", FOR_NAME_METHOD_DESCRIPTOR, false);
 }
  /**
   * Generates an implementation of the given managed type.
   *
   * <p>The generated class will implement/extend the managed type and will:
   *
   * <ul>
   *   <li>provide implementations for abstract getters and setters that delegate to model nodes
   *   <li>provide a `toString()` implementation
   *   <li>mix-in implementation of {@link ManagedInstance}
   *   <li>provide a constructor that accepts a {@link ModelElementState}, which will be used to
   *       implement the above.
   * </ul>
   *
   * In case a delegate schema is supplied, the generated class will also have:
   *
   * <ul>
   *   <li>a constructor that also takes a delegate instance
   *   <li>methods that call through to the delegate instance
   * </ul>
   */
  public <T, M extends T, D extends T> Class<? extends M> generate(
      StructSchema<M> viewSchema, @Nullable StructSchema<D> delegateSchema) {
    if (delegateSchema != null
        && Modifier.isAbstract(delegateSchema.getType().getConcreteClass().getModifiers())) {
      throw new IllegalArgumentException("Delegate type must be null or a non-abstract type");
    }
    ClassWriter visitor = new ClassWriter(ClassWriter.COMPUTE_MAXS | ClassWriter.COMPUTE_FRAMES);

    ModelType<M> viewType = viewSchema.getType();

    StringBuilder generatedTypeNameBuilder = new StringBuilder(viewType.getName());
    if (delegateSchema != null) {
      generatedTypeNameBuilder
          .append("$BackedBy_")
          .append(delegateSchema.getType().getName().replaceAll("\\.", "_"));
    } else {
      generatedTypeNameBuilder.append("$Impl");
    }

    String generatedTypeName = generatedTypeNameBuilder.toString();
    Type generatedType = Type.getType("L" + generatedTypeName.replaceAll("\\.", "/") + ";");

    Class<M> viewClass = viewType.getConcreteClass();
    Class<?> superclass;
    final ImmutableSet.Builder<String> interfacesToImplement = ImmutableSet.builder();
    final ImmutableSet.Builder<Class<?>> typesToDelegate = ImmutableSet.builder();
    typesToDelegate.add(viewClass);
    interfacesToImplement.add(MANAGED_INSTANCE_TYPE);
    if (viewClass.isInterface()) {
      superclass = Object.class;
      interfacesToImplement.add(Type.getInternalName(viewClass));
    } else {
      superclass = viewClass;
    }
    // TODO:LPTR This should be removed once BinaryContainer is a ModelMap
    // We need to also implement all the interfaces of the delegate type because otherwise
    // BinaryContainer won't recognize managed binaries as BinarySpecInternal
    if (delegateSchema != null) {
      ModelSchemaUtils.walkTypeHierarchy(
          delegateSchema.getType().getConcreteClass(),
          new ModelSchemaUtils.TypeVisitor<D>() {
            @Override
            public void visitType(Class<? super D> type) {
              if (type.isInterface()) {
                typesToDelegate.add(type);
                interfacesToImplement.add(Type.getInternalName(type));
              }
            }
          });
    }

    generateProxyClass(
        visitor,
        viewSchema,
        delegateSchema,
        interfacesToImplement.build(),
        typesToDelegate.build(),
        generatedType,
        Type.getType(superclass));

    ClassLoader targetClassLoader = viewClass.getClassLoader();
    if (delegateSchema != null) {
      // TODO - remove this once the above is removed
      try {
        viewClass.getClassLoader().loadClass(delegateSchema.getType().getConcreteClass().getName());
      } catch (ClassNotFoundException e) {
        // Delegate class is not visible to managed view type -> view type is more general than
        // delegate type, so use the delegate classloader instead
        targetClassLoader = delegateSchema.getType().getConcreteClass().getClassLoader();
      }
    }

    return defineClass(visitor, targetClassLoader, generatedTypeName);
  }