mojo::Serialize*_() calls now propogate/return validation errors.

mojo/public/cpp/bindings/lib/array_serialization.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MOJO_PUBLIC_CPP_BINDINGS_LIB_ARRAY_SERIALIZATION_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_LIB_ARRAY_SERIALIZATION_H_
 
 #include <string.h>  // For |memcpy()|.
 #include <vector>
 
@@ skipping 27 matching lines @@
 
 // Handles serialization and deserialization of arrays of pod types.
 template <typename E, typename F>
 struct ArraySerializer<E, F, false> {
   static_assert(sizeof(E) == sizeof(F), "Incorrect array serializer");
   static size_t GetSerializedSize(const Array<E>& input) {
     return sizeof(Array_Data<F>) + Align(input.size() * sizeof(E));
   }
 
   template <typename Iterator>
-  static void SerializeElements(Iterator it,
-                                size_t num_elements,
-                                Buffer* buf,
-                                Array_Data<F>* output,
-                                const ArrayValidateParams* validate_params) {
+  static ValidationError SerializeElements(
+      Iterator it,
+      size_t num_elements,
+      Buffer* buf,
+      Array_Data<F>* output,
+      const ArrayValidateParams* validate_params) {
     MOJO_DCHECK(!validate_params->element_is_nullable)
         << "Primitive type should be non-nullable";
     MOJO_DCHECK(!validate_params->element_validate_params)
         << "Primitive type should not have array validate params";
     for (size_t i = 0; i < num_elements; ++i, ++it)
       output->at(i) = *it;
+
+    return ValidationError::VALIDATION_ERROR_NONE;

[viettrungluu, 2015/10/06 16:40:06]

Since ValidationError is (not yet!) a class enum, the ValidationError:: is
redundant.

On the other hand, feel free to change it to a class enum, in which case the
value names should be named like NONE (hence ValidationError::NONE) instead of
VALIDATION_ERROR_NONE.

[vardhan, 2015/10/06 22:57:14]

That was my plan, but since ValidationError is used in bunch of other files too,
I was thinking of doing a follow up CL to fix those.  I'll do the rename too.

[viettrungluu, 2015/10/08 15:51:25]

OK, but for now, ValidationError::VALIDATION_ERROR_NONE is weird and redundant.
Just writing VALIDATION_ERROR_NONE will make future search-and-replace easier
too.

[vardhan, 2015/10/08 20:53:51]

Done.

   }
 
   // We can optimize serializing PODs by |memcpy|ing directly.
   // Note that this has precedence over its templated sibling defined above.
-  static void SerializeElements(typename Array<E>::Iterator it,
-                                size_t num_elements,
-                                Buffer* buf,
-                                Array_Data<F>* output,
-                                const ArrayValidateParams* validate_params) {
+  static ValidationError SerializeElements(
+      typename Array<E>::Iterator it,
+      size_t num_elements,
+      Buffer* buf,
+      Array_Data<F>* output,
+      const ArrayValidateParams* validate_params) {
     MOJO_DCHECK(!validate_params->element_is_nullable)
         << "Primitive type should be non-nullable";
     MOJO_DCHECK(!validate_params->element_validate_params)
         << "Primitive type should not have array validate params";
     if (num_elements)
       memcpy(output->storage(), &(*it), num_elements * sizeof(E));
+
+    return ValidationError::VALIDATION_ERROR_NONE;
   }
 
   static void DeserializeElements(Array_Data<F>* input, Array<E>* output) {
     std::vector<E> result(input->size());
     if (input->size())
       memcpy(&result[0], input->storage(), input->size() * sizeof(E));
     output->Swap(&result);
   }
 };
 
 // Serializes and deserializes arrays of bools.
 template <>
 struct ArraySerializer<bool, bool, false> {
   static size_t GetSerializedSize(const Array<bool>& input) {
     return sizeof(Array_Data<bool>) + Align((input.size() + 7) / 8);
   }
 
   template <typename Iterator>
-  static void SerializeElements(Iterator it,
-                                size_t num_elements,
-                                Buffer* buf,
-                                Array_Data<bool>* output,
-                                const ArrayValidateParams* validate_params) {
+  static ValidationError SerializeElements(
+      Iterator it,
+      size_t num_elements,
+      Buffer* buf,
+      Array_Data<bool>* output,
+      const ArrayValidateParams* validate_params) {
     MOJO_DCHECK(!validate_params->element_is_nullable)
         << "Primitive type should be non-nullable";
     MOJO_DCHECK(!validate_params->element_validate_params)
         << "Primitive type should not have array validate params";
 
     // TODO(darin): Can this be a memcpy somehow instead of a bit-by-bit copy?
     for (size_t i = 0; i < num_elements; ++i, ++it)
       output->at(i) = *it;
+
+    return ValidationError::VALIDATION_ERROR_NONE;
   }
 
   static void DeserializeElements(Array_Data<bool>* input,
                                   Array<bool>* output) {
     Array<bool> result(input->size());
     // TODO(darin): Can this be a memcpy somehow instead of a bit-by-bit copy?
     for (size_t i = 0; i < input->size(); ++i)
       result.at(i) = input->at(i);
     output->Swap(&result);
   }
 };
 
 // Serializes and deserializes arrays of handles.
 template <typename H>
 struct ArraySerializer<ScopedHandleBase<H>, H, false> {
   static size_t GetSerializedSize(const Array<ScopedHandleBase<H>>& input) {
     return sizeof(Array_Data<H>) + Align(input.size() * sizeof(H));
   }
 
   template <typename Iterator>
-  static void SerializeElements(Iterator it,
-                                size_t num_elements,
-                                Buffer* buf,
-                                Array_Data<H>* output,
-                                const ArrayValidateParams* validate_params) {
+  static ValidationError SerializeElements(
+      Iterator it,
+      size_t num_elements,
+      Buffer* buf,
+      Array_Data<H>* output,
+      const ArrayValidateParams* validate_params) {
     MOJO_DCHECK(!validate_params->element_validate_params)
         << "Handle type should not have array validate params";
 
     for (size_t i = 0; i < num_elements; ++i, ++it) {
       // Transfer ownership of the handle.
       output->at(i) = it->release();
-      MOJO_INTERNAL_DLOG_SERIALIZATION_WARNING(
+      MOJO_INTERNAL_SERIALIZATION_CHECK_AND_RETURN(
           !validate_params->element_is_nullable && !output->at(i).is_valid(),
-          VALIDATION_ERROR_UNEXPECTED_INVALID_HANDLE,
+          ValidationError::VALIDATION_ERROR_UNEXPECTED_INVALID_HANDLE,
           MakeMessageWithArrayIndex(
               "invalid handle in array expecting valid handles", num_elements,
               i));
     }
+
+    return ValidationError::VALIDATION_ERROR_NONE;
   }
 
   static void DeserializeElements(Array_Data<H>* input,
                                   Array<ScopedHandleBase<H>>* output) {
     Array<ScopedHandleBase<H>> result(input->size());
     for (size_t i = 0; i < input->size(); ++i)
       result.at(i) = MakeScopedHandle(FetchAndReset(&input->at(i)));
     output->Swap(&result);
   }
 };
@@ skipping 11 matching lines @@
       typename RemovePointer<typename WrapperTraits<S>::DataType>::type S_Data;
   static size_t GetSerializedSize(const Array<S>& input) {
     size_t size = sizeof(Array_Data<S_Data*>) +
                   input.size() * sizeof(StructPointer<S_Data>);
     for (size_t i = 0; i < input.size(); ++i)
       size += GetSerializedSize_(*(UnwrapConstStructPtr<S>::value(input[i])));
     return size;
   }
 
   template <typename Iterator>
-  static void SerializeElements(Iterator it,
-                                size_t num_elements,
-                                Buffer* buf,
-                                Array_Data<S_Data*>* output,
-                                const ArrayValidateParams* validate_params) {
+  static ValidationError SerializeElements(
+      Iterator it,
+      size_t num_elements,
+      Buffer* buf,
+      Array_Data<S_Data*>* output,
+      const ArrayValidateParams* validate_params) {
     for (size_t i = 0; i < num_elements; ++i, ++it) {
       S_Data* element;
-      SerializeCaller::Run(&(*it), buf, &element,
-                           validate_params->element_validate_params);
+      auto retval = SerializeCaller::Run(
+          &(*it), buf, &element, validate_params->element_validate_params);
+      if (retval != ValidationError::VALIDATION_ERROR_NONE)
+        return retval;
+
       output->at(i) = element;
-      MOJO_INTERNAL_DLOG_SERIALIZATION_WARNING(
+      MOJO_INTERNAL_SERIALIZATION_CHECK_AND_RETURN(
           !validate_params->element_is_nullable && !element,
-          VALIDATION_ERROR_UNEXPECTED_NULL_POINTER,
+          ValidationError::VALIDATION_ERROR_UNEXPECTED_NULL_POINTER,
           MakeMessageWithArrayIndex("null in array expecting valid pointers",
                                     num_elements, i));
     }
+
+    return ValidationError::VALIDATION_ERROR_NONE;
   }
 
   static void DeserializeElements(Array_Data<S_Data*>* input,
                                   Array<S>* output) {
     Array<S> result(input->size());
     for (size_t i = 0; i < input->size(); ++i) {
       DeserializeCaller::Run(input->at(i), &result[i]);
     }
     output->Swap(&result);
   }
 
  private:
   // SerializeCaller template is used by |ArraySerializer| to dispatch a
   // serialize call on a non-POD type.  This template is defined outside
   // |ArraySerializer| since you cannot specialize a struct within a class
   // definition.
   struct SerializeCaller {
     // This template needs to be suppressed if |T| is |String|, otherwise it
     // takes precedence over the |String|-overloaded Run() below.
     template <typename T,
               typename = typename EnableIf<!IsSame<T, String>::value, T>::type>
-    static void Run(T* input,
-                    Buffer* buf,
-                    typename WrapperTraits<T>::DataType* output,
-                    const ArrayValidateParams* validate_params) {
+    static ValidationError Run(T* input,
+                               Buffer* buf,
+                               typename WrapperTraits<T>::DataType* output,
+                               const ArrayValidateParams* validate_params) {
       MOJO_DCHECK(!validate_params)
           << "Struct type should not have array validate params";
-      Serialize_(UnwrapStructPtr<T>::value(*input), buf, output);
+      return Serialize_(UnwrapStructPtr<T>::value(*input), buf, output);
     }
 
-    static void Run(const String* input,
-                    Buffer* buf,
-                    String_Data** output,
-                    const ArrayValidateParams* validate_params) {
+    static ValidationError Run(const String* input,
+                               Buffer* buf,
+                               String_Data** output,
+                               const ArrayValidateParams* validate_params) {
       MOJO_DCHECK(validate_params &&
                   !validate_params->element_validate_params &&
                   !validate_params->element_is_nullable &&
                   validate_params->expected_num_elements == 0)
           << "String type has unexpected array validate params";
       SerializeString_(*input, buf, output);
+      return ValidationError::VALIDATION_ERROR_NONE;
     }
 
     template <typename T>
-    static void Run(Array<T>* input,
-                    Buffer* buf,
-                    typename Array<T>::Data_** output,
-                    const ArrayValidateParams* validate_params) {
-      SerializeArray_(input, buf, output, validate_params);
+    static ValidationError Run(Array<T>* input,
+                               Buffer* buf,
+                               typename Array<T>::Data_** output,
+                               const ArrayValidateParams* validate_params) {
+      return SerializeArray_(input, buf, output, validate_params);
     }
 
     template <typename Key, typename Value>
-    static void Run(Map<Key, Value>* input,
-                    Buffer* buf,
-                    typename Map<Key, Value>::Data_** output,
-                    const ArrayValidateParams* validate_params) {
-      SerializeMap_(input, buf, output, validate_params);
+    static ValidationError Run(Map<Key, Value>* input,
+                               Buffer* buf,
+                               typename Map<Key, Value>::Data_** output,
+                               const ArrayValidateParams* validate_params) {
+      return SerializeMap_(input, buf, output, validate_params);
     }
   };
 
   struct DeserializeCaller {
     template <typename T>
     static void Run(typename WrapperTraits<T>::DataType input, T* output) {
       Deserialize_(input, output);
     }
 
     // Since Deserialize_ takes in a |Struct*| (not |StructPtr|), we need to
@@ skipping 24 matching lines @@
     size_t size = sizeof(Array_Data<U_Data>);
     for (size_t i = 0; i < input.size(); ++i) {
       // GetSerializedSize_ will account for both the data in the union and the
       // space in the array used to hold the union.
       size += GetSerializedSize_(input[i], false);
     }
     return size;
   }
 
   template <typename Iterator>
-  static void SerializeElements(Iterator it,
-                                size_t num_elements,
-                                Buffer* buf,
-                                Array_Data<U_Data>* output,
-                                const ArrayValidateParams* validate_params) {
+  static ValidationError SerializeElements(
+      Iterator it,
+      size_t num_elements,
+      Buffer* buf,
+      Array_Data<U_Data>* output,
+      const ArrayValidateParams* validate_params) {
     for (size_t i = 0; i < num_elements; ++i, ++it) {
       U_Data* result = output->storage() + i;
-      SerializeUnion_(it->get(), buf, &result, true);
-      MOJO_INTERNAL_DLOG_SERIALIZATION_WARNING(
+      auto retval = SerializeUnion_(it->get(), buf, &result, true);
+      if (retval != ValidationError::VALIDATION_ERROR_NONE)
+        return retval;
+      MOJO_INTERNAL_SERIALIZATION_CHECK_AND_RETURN(
           !validate_params->element_is_nullable && output->at(i).is_null(),
-          VALIDATION_ERROR_UNEXPECTED_NULL_POINTER,
+          ValidationError::VALIDATION_ERROR_UNEXPECTED_NULL_POINTER,
           MakeMessageWithArrayIndex("null in array expecting valid unions",
                                     num_elements, i));
     }
+
+    return ValidationError::VALIDATION_ERROR_NONE;
   }
 
   static void DeserializeElements(Array_Data<U_Data>* input, Array<U>* output) {
     Array<U> result(input->size());
     for (size_t i = 0; i < input->size(); ++i) {
       auto& elem = input->at(i);
       if (!elem.is_null()) {
         using UnwrapedUnionType = typename RemoveStructPtr<U>::type;
         result[i] = UnwrapedUnionType::New();
         Deserialize_(&elem, result[i].get());
       }
     }
     output->Swap(&result);
   }
 };
 
 }  // namespace internal
 
 template <typename E>
 inline size_t GetSerializedSize_(const Array<E>& input) {
   if (!input)
     return 0;
   typedef typename internal::WrapperTraits<E>::DataType F;
   return internal::ArraySerializer<E, F>::GetSerializedSize(input);
 }
 
 template <typename E, typename F>
-inline void SerializeArray_(
+inline internal::ValidationError SerializeArray_(
     Array<E>* input,
     internal::Buffer* buf,
     internal::Array_Data<F>** output,
     const internal::ArrayValidateParams* validate_params) {
   MOJO_DCHECK(input);
   if (*input) {
-    MOJO_INTERNAL_DLOG_SERIALIZATION_WARNING(
+    MOJO_INTERNAL_SERIALIZATION_CHECK_AND_RETURN(
         validate_params->expected_num_elements != 0 &&
             input->size() != validate_params->expected_num_elements,
-        internal::VALIDATION_ERROR_UNEXPECTED_ARRAY_HEADER,
+        internal::ValidationError::VALIDATION_ERROR_UNEXPECTED_ARRAY_HEADER,
         internal::MakeMessageWithExpectedArraySize(
             "fixed-size array has wrong number of elements", input->size(),
             validate_params->expected_num_elements));
 
     internal::Array_Data<F>* result =
         internal::Array_Data<F>::New(input->size(), buf);
     if (result) {
-      internal::ArraySerializer<E, F>::SerializeElements(
+      auto retval = internal::ArraySerializer<E, F>::SerializeElements(
           input->begin(), input->size(), buf, result, validate_params);
+      if (retval != internal::ValidationError::VALIDATION_ERROR_NONE) {
+        return retval;
+      }
     }
     *output = result;
   } else {
+    // It is up to the caller to make the given |Array| is not null if it is
+    // not nullable.
     *output = nullptr;
   }
+
+  return internal::ValidationError::VALIDATION_ERROR_NONE;
 }
 
 template <typename E, typename F>
 inline void Deserialize_(internal::Array_Data<F>* input, Array<E>* output) {
   if (input) {
     internal::ArraySerializer<E, F>::DeserializeElements(input, output);
   } else {
     output->reset();
   }
 }
 
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_LIB_ARRAY_SERIALIZATION_H_