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// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc. All rights reserved.
// https://developers.google.com/protocol-buffers/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// Author: kenton@google.com (Kenton Varda)
// Based on original Protocol Buffers design by
// Sanjay Ghemawat, Jeff Dean, and others.
//
// This header is logically internal, but is made public because it is used
// from protocol-compiler-generated code, which may reside in other components.
#ifndef GOOGLE_PROTOBUF_GENERATED_MESSAGE_REFLECTION_H__
#define GOOGLE_PROTOBUF_GENERATED_MESSAGE_REFLECTION_H__
#include <string>
#include <vector>
#include <google/protobuf/stubs/casts.h>
#include <google/protobuf/stubs/common.h>
// TODO(jasonh): Remove this once the compiler change to directly include this
// is released to components.
#include <google/protobuf/generated_enum_reflection.h>
#include <google/protobuf/message.h>
#include <google/protobuf/metadata.h>
#include <google/protobuf/unknown_field_set.h>
namespace google {
namespace upb {
namespace google_opensource {
class GMR_Handlers;
} // namespace google_opensource
} // namespace upb
namespace protobuf {
class DescriptorPool;
class MapKey;
class MapValueRef;
}
namespace protobuf {
namespace internal {
class DefaultEmptyOneof;
// Defined in this file.
class GeneratedMessageReflection;
// Defined in other files.
class ExtensionSet; // extension_set.h
// THIS CLASS IS NOT INTENDED FOR DIRECT USE. It is intended for use
// by generated code. This class is just a big hack that reduces code
// size.
//
// A GeneratedMessageReflection is an implementation of Reflection
// which expects all fields to be backed by simple variables located in
// memory. The locations are given using a base pointer and a set of
// offsets.
//
// It is required that the user represents fields of each type in a standard
// way, so that GeneratedMessageReflection can cast the void* pointer to
// the appropriate type. For primitive fields and string fields, each field
// should be represented using the obvious C++ primitive type. Enums and
// Messages are different:
// - Singular Message fields are stored as a pointer to a Message. These
// should start out NULL, except for in the default instance where they
// should start out pointing to other default instances.
// - Enum fields are stored as an int. This int must always contain
// a valid value, such that EnumDescriptor::FindValueByNumber() would
// not return NULL.
// - Repeated fields are stored as RepeatedFields or RepeatedPtrFields
// of whatever type the individual field would be. Strings and
// Messages use RepeatedPtrFields while everything else uses
// RepeatedFields.
class LIBPROTOBUF_EXPORT GeneratedMessageReflection : public Reflection {
public:
// Constructs a GeneratedMessageReflection.
// Parameters:
// descriptor: The descriptor for the message type being implemented.
// default_instance: The default instance of the message. This is only
// used to obtain pointers to default instances of embedded
// messages, which GetMessage() will return if the particular
// sub-message has not been initialized yet. (Thus, all
// embedded message fields *must* have non-NULL pointers
// in the default instance.)
// offsets: An array of ints giving the byte offsets, relative to
// the start of the message object, of each field. These can
// be computed at compile time using the
// GOOGLE_PROTOBUF_GENERATED_MESSAGE_FIELD_OFFSET() macro, defined
// below.
// has_bits_offset: Offset in the message of an array of uint32s of size
// descriptor->field_count()/32, rounded up. This is a
// bitfield where each bit indicates whether or not the
// corresponding field of the message has been initialized.
// The bit for field index i is obtained by the expression:
// has_bits[i / 32] & (1 << (i % 32))
// unknown_fields_offset: Offset in the message of the UnknownFieldSet for
// the message.
// extensions_offset: Offset in the message of the ExtensionSet for the
// message, or -1 if the message type has no extension
// ranges.
// pool: DescriptorPool to search for extension definitions. Only
// used by FindKnownExtensionByName() and
// FindKnownExtensionByNumber().
// factory: MessageFactory to use to construct extension messages.
// object_size: The size of a message object of this type, as measured
// by sizeof().
GeneratedMessageReflection(const Descriptor* descriptor,
const Message* default_instance,
const int offsets[],
int has_bits_offset,
int unknown_fields_offset,
int extensions_offset,
const DescriptorPool* pool,
MessageFactory* factory,
int object_size,
int arena_offset,
int is_default_instance_offset = -1);
// Similar with the construction above. Call this construction if the
// message has oneof definition.
// Parameters:
// offsets: An array of ints giving the byte offsets.
// For each oneof field, the offset is relative to the
// default_oneof_instance. These can be computed at compile
// time using the
// PROTO2_GENERATED_DEFAULT_ONEOF_FIELD_OFFSET() macro.
// For each none oneof field, the offset is related to
// the start of the message object. These can be computed
// at compile time using the
// GOOGLE_PROTOBUF_GENERATED_MESSAGE_FIELD_OFFSET() macro.
// Besides offsets for all fields, this array also contains
// offsets for oneof unions. The offset of the i-th oneof
// union is offsets[descriptor->field_count() + i].
// default_oneof_instance: The default instance of the oneofs. It is a
// struct holding the default value of all oneof fields
// for this message. It is only used to obtain pointers
// to default instances of oneof fields, which Get
// methods will return if the field is not set.
// oneof_case_offset: Offset in the message of an array of uint32s of
// size descriptor->oneof_decl_count(). Each uint32
// indicates what field is set for each oneof.
// other parameters are the same with the construction above.
GeneratedMessageReflection(const Descriptor* descriptor,
const Message* default_instance,
const int offsets[],
int has_bits_offset,
int unknown_fields_offset,
int extensions_offset,
const void* default_oneof_instance,
int oneof_case_offset,
const DescriptorPool* pool,
MessageFactory* factory,
int object_size,
int arena_offset,
int is_default_instance_offset = -1);
~GeneratedMessageReflection();
// Shorter-to-call helpers for the above two constructions that work if the
// pool and factory are the usual, namely, DescriptorPool::generated_pool()
// and MessageFactory::generated_factory().
static GeneratedMessageReflection* NewGeneratedMessageReflection(
const Descriptor* descriptor,
const Message* default_instance,
const int offsets[],
int has_bits_offset,
int unknown_fields_offset,
int extensions_offset,
const void* default_oneof_instance,
int oneof_case_offset,
int object_size,
int arena_offset,
int is_default_instance_offset = -1);
static GeneratedMessageReflection* NewGeneratedMessageReflection(
const Descriptor* descriptor,
const Message* default_instance,
const int offsets[],
int has_bits_offset,
int unknown_fields_offset,
int extensions_offset,
int object_size,
int arena_offset,
int is_default_instance_offset = -1);
// implements Reflection -------------------------------------------
const UnknownFieldSet& GetUnknownFields(const Message& message) const;
UnknownFieldSet* MutableUnknownFields(Message* message) const;
int SpaceUsed(const Message& message) const;
bool HasField(const Message& message, const FieldDescriptor* field) const;
int FieldSize(const Message& message, const FieldDescriptor* field) const;
void ClearField(Message* message, const FieldDescriptor* field) const;
bool HasOneof(const Message& message,
const OneofDescriptor* oneof_descriptor) const;
void ClearOneof(Message* message, const OneofDescriptor* field) const;
void RemoveLast(Message* message, const FieldDescriptor* field) const;
Message* ReleaseLast(Message* message, const FieldDescriptor* field) const;
void Swap(Message* message1, Message* message2) const;
void SwapFields(Message* message1, Message* message2,
const vector<const FieldDescriptor*>& fields) const;
void SwapElements(Message* message, const FieldDescriptor* field,
int index1, int index2) const;
void ListFields(const Message& message,
vector<const FieldDescriptor*>* output) const;
int32 GetInt32 (const Message& message,
const FieldDescriptor* field) const;
int64 GetInt64 (const Message& message,
const FieldDescriptor* field) const;
uint32 GetUInt32(const Message& message,
const FieldDescriptor* field) const;
uint64 GetUInt64(const Message& message,
const FieldDescriptor* field) const;
float GetFloat (const Message& message,
const FieldDescriptor* field) const;
double GetDouble(const Message& message,
const FieldDescriptor* field) const;
bool GetBool (const Message& message,
const FieldDescriptor* field) const;
string GetString(const Message& message,
const FieldDescriptor* field) const;
const string& GetStringReference(const Message& message,
const FieldDescriptor* field,
string* scratch) const;
const EnumValueDescriptor* GetEnum(const Message& message,
const FieldDescriptor* field) const;
int GetEnumValue(const Message& message,
const FieldDescriptor* field) const;
const Message& GetMessage(const Message& message,
const FieldDescriptor* field,
MessageFactory* factory = NULL) const;
const FieldDescriptor* GetOneofFieldDescriptor(
const Message& message,
const OneofDescriptor* oneof_descriptor) const;
private:
bool ContainsMapKey(const Message& message,
const FieldDescriptor* field,
const MapKey& key) const;
bool InsertOrLookupMapValue(Message* message,
const FieldDescriptor* field,
const MapKey& key,
MapValueRef* val) const;
bool DeleteMapValue(Message* message,
const FieldDescriptor* field,
const MapKey& key) const;
MapIterator MapBegin(
Message* message,
const FieldDescriptor* field) const;
MapIterator MapEnd(
Message* message,
const FieldDescriptor* field) const;
int MapSize(const Message& message, const FieldDescriptor* field) const;
public:
void SetInt32 (Message* message,
const FieldDescriptor* field, int32 value) const;
void SetInt64 (Message* message,
const FieldDescriptor* field, int64 value) const;
void SetUInt32(Message* message,
const FieldDescriptor* field, uint32 value) const;
void SetUInt64(Message* message,
const FieldDescriptor* field, uint64 value) const;
void SetFloat (Message* message,
const FieldDescriptor* field, float value) const;
void SetDouble(Message* message,
const FieldDescriptor* field, double value) const;
void SetBool (Message* message,
const FieldDescriptor* field, bool value) const;
void SetString(Message* message,
const FieldDescriptor* field,
const string& value) const;
void SetEnum (Message* message, const FieldDescriptor* field,
const EnumValueDescriptor* value) const;
void SetEnumValue(Message* message, const FieldDescriptor* field,
int value) const;
Message* MutableMessage(Message* message, const FieldDescriptor* field,
MessageFactory* factory = NULL) const;
void SetAllocatedMessage(Message* message,
Message* sub_message,
const FieldDescriptor* field) const;
Message* ReleaseMessage(Message* message, const FieldDescriptor* field,
MessageFactory* factory = NULL) const;
int32 GetRepeatedInt32 (const Message& message,
const FieldDescriptor* field, int index) const;
int64 GetRepeatedInt64 (const Message& message,
const FieldDescriptor* field, int index) const;
uint32 GetRepeatedUInt32(const Message& message,
const FieldDescriptor* field, int index) const;
uint64 GetRepeatedUInt64(const Message& message,
const FieldDescriptor* field, int index) const;
float GetRepeatedFloat (const Message& message,
const FieldDescriptor* field, int index) const;
double GetRepeatedDouble(const Message& message,
const FieldDescriptor* field, int index) const;
bool GetRepeatedBool (const Message& message,
const FieldDescriptor* field, int index) const;
string GetRepeatedString(const Message& message,
const FieldDescriptor* field, int index) const;
const string& GetRepeatedStringReference(const Message& message,
const FieldDescriptor* field,
int index, string* scratch) const;
const EnumValueDescriptor* GetRepeatedEnum(const Message& message,
const FieldDescriptor* field,
int index) const;
int GetRepeatedEnumValue(const Message& message,
const FieldDescriptor* field,
int index) const;
const Message& GetRepeatedMessage(const Message& message,
const FieldDescriptor* field,
int index) const;
// Set the value of a field.
void SetRepeatedInt32 (Message* message,
const FieldDescriptor* field, int index, int32 value) const;
void SetRepeatedInt64 (Message* message,
const FieldDescriptor* field, int index, int64 value) const;
void SetRepeatedUInt32(Message* message,
const FieldDescriptor* field, int index, uint32 value) const;
void SetRepeatedUInt64(Message* message,
const FieldDescriptor* field, int index, uint64 value) const;
void SetRepeatedFloat (Message* message,
const FieldDescriptor* field, int index, float value) const;
void SetRepeatedDouble(Message* message,
const FieldDescriptor* field, int index, double value) const;
void SetRepeatedBool (Message* message,
const FieldDescriptor* field, int index, bool value) const;
void SetRepeatedString(Message* message,
const FieldDescriptor* field, int index,
const string& value) const;
void SetRepeatedEnum(Message* message, const FieldDescriptor* field,
int index, const EnumValueDescriptor* value) const;
void SetRepeatedEnumValue(Message* message, const FieldDescriptor* field,
int index, int value) const;
// Get a mutable pointer to a field with a message type.
Message* MutableRepeatedMessage(Message* message,
const FieldDescriptor* field,
int index) const;
void AddInt32 (Message* message,
const FieldDescriptor* field, int32 value) const;
void AddInt64 (Message* message,
const FieldDescriptor* field, int64 value) const;
void AddUInt32(Message* message,
const FieldDescriptor* field, uint32 value) const;
void AddUInt64(Message* message,
const FieldDescriptor* field, uint64 value) const;
void AddFloat (Message* message,
const FieldDescriptor* field, float value) const;
void AddDouble(Message* message,
const FieldDescriptor* field, double value) const;
void AddBool (Message* message,
const FieldDescriptor* field, bool value) const;
void AddString(Message* message,
const FieldDescriptor* field, const string& value) const;
void AddEnum(Message* message,
const FieldDescriptor* field,
const EnumValueDescriptor* value) const;
void AddEnumValue(Message* message,
const FieldDescriptor* field,
int value) const;
Message* AddMessage(Message* message, const FieldDescriptor* field,
MessageFactory* factory = NULL) const;
void AddAllocatedMessage(
Message* message, const FieldDescriptor* field,
Message* new_entry) const;
const FieldDescriptor* FindKnownExtensionByName(const string& name) const;
const FieldDescriptor* FindKnownExtensionByNumber(int number) const;
bool SupportsUnknownEnumValues() const;
// This value for arena_offset_ indicates that there is no arena pointer in
// this message (e.g., old generated code).
static const int kNoArenaPointer = -1;
// This value for unknown_field_offset_ indicates that there is no
// UnknownFieldSet in this message, and that instead, we are using the
// Zero-Overhead Arena Pointer trick. When this is the case, arena_offset_
// actually indexes to an InternalMetadataWithArena instance, which can return
// either an arena pointer or an UnknownFieldSet or both. It is never the case
// that unknown_field_offset_ == kUnknownFieldSetInMetadata && arena_offset_
// == kNoArenaPointer.
static const int kUnknownFieldSetInMetadata = -1;
protected:
void* MutableRawRepeatedField(
Message* message, const FieldDescriptor* field, FieldDescriptor::CppType,
int ctype, const Descriptor* desc) const;
const void* GetRawRepeatedField(
const Message& message, const FieldDescriptor* field,
FieldDescriptor::CppType, int ctype,
const Descriptor* desc) const;
virtual MessageFactory* GetMessageFactory() const;
virtual void* RepeatedFieldData(
Message* message, const FieldDescriptor* field,
FieldDescriptor::CppType cpp_type,
const Descriptor* message_type) const;
private:
friend class GeneratedMessage;
// To parse directly into a proto2 generated class, the class GMR_Handlers
// needs access to member offsets and hasbits.
friend class upb::google_opensource::GMR_Handlers;
const Descriptor* descriptor_;
const Message* default_instance_;
const void* default_oneof_instance_;
const int* offsets_;
int has_bits_offset_;
int oneof_case_offset_;
int unknown_fields_offset_;
int extensions_offset_;
int arena_offset_;
int is_default_instance_offset_;
int object_size_;
static const int kHasNoDefaultInstanceField = -1;
const DescriptorPool* descriptor_pool_;
MessageFactory* message_factory_;
template <typename Type>
inline const Type& GetRaw(const Message& message,
const FieldDescriptor* field) const;
template <typename Type>
inline Type* MutableRaw(Message* message,
const FieldDescriptor* field) const;
template <typename Type>
inline const Type& DefaultRaw(const FieldDescriptor* field) const;
template <typename Type>
inline const Type& DefaultOneofRaw(const FieldDescriptor* field) const;
inline const uint32* GetHasBits(const Message& message) const;
inline uint32* MutableHasBits(Message* message) const;
inline uint32 GetOneofCase(
const Message& message,
const OneofDescriptor* oneof_descriptor) const;
inline uint32* MutableOneofCase(
Message* message,
const OneofDescriptor* oneof_descriptor) const;
inline const ExtensionSet& GetExtensionSet(const Message& message) const;
inline ExtensionSet* MutableExtensionSet(Message* message) const;
inline Arena* GetArena(Message* message) const;
inline const internal::InternalMetadataWithArena&
GetInternalMetadataWithArena(const Message& message) const;
inline internal::InternalMetadataWithArena*
MutableInternalMetadataWithArena(Message* message) const;
inline bool GetIsDefaultInstance(const Message& message) const;
inline bool HasBit(const Message& message,
const FieldDescriptor* field) const;
inline void SetBit(Message* message,
const FieldDescriptor* field) const;
inline void ClearBit(Message* message,
const FieldDescriptor* field) const;
inline void SwapBit(Message* message1,
Message* message2,
const FieldDescriptor* field) const;
// This function only swaps the field. Should swap corresponding has_bit
// before or after using this function.
void SwapField(Message* message1,
Message* message2,
const FieldDescriptor* field) const;
void SwapOneofField(Message* message1,
Message* message2,
const OneofDescriptor* oneof_descriptor) const;
inline bool HasOneofField(const Message& message,
const FieldDescriptor* field) const;
inline void SetOneofCase(Message* message,
const FieldDescriptor* field) const;
inline void ClearOneofField(Message* message,
const FieldDescriptor* field) const;
template <typename Type>
inline const Type& GetField(const Message& message,
const FieldDescriptor* field) const;
template <typename Type>
inline void SetField(Message* message,
const FieldDescriptor* field, const Type& value) const;
template <typename Type>
inline Type* MutableField(Message* message,
const FieldDescriptor* field) const;
template <typename Type>
inline const Type& GetRepeatedField(const Message& message,
const FieldDescriptor* field,
int index) const;
template <typename Type>
inline const Type& GetRepeatedPtrField(const Message& message,
const FieldDescriptor* field,
int index) const;
template <typename Type>
inline void SetRepeatedField(Message* message,
const FieldDescriptor* field, int index,
Type value) const;
template <typename Type>
inline Type* MutableRepeatedField(Message* message,
const FieldDescriptor* field,
int index) const;
template <typename Type>
inline void AddField(Message* message,
const FieldDescriptor* field, const Type& value) const;
template <typename Type>
inline Type* AddField(Message* message,
const FieldDescriptor* field) const;
int GetExtensionNumberOrDie(const Descriptor* type) const;
// Internal versions of EnumValue API perform no checking. Called after checks
// by public methods.
void SetEnumValueInternal(Message* message,
const FieldDescriptor* field,
int value) const;
void SetRepeatedEnumValueInternal(Message* message,
const FieldDescriptor* field,
int index,
int value) const;
void AddEnumValueInternal(Message* message,
const FieldDescriptor* field,
int value) const;
Message* UnsafeArenaReleaseMessage(Message* message,
const FieldDescriptor* field,
MessageFactory* factory = NULL) const;
void UnsafeArenaSetAllocatedMessage(Message* message,
Message* sub_message,
const FieldDescriptor* field) const;
internal::MapFieldBase* MapData(
Message* message, const FieldDescriptor* field) const;
GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(GeneratedMessageReflection);
};
// Returns the offset of the given field within the given aggregate type.
// This is equivalent to the ANSI C offsetof() macro. However, according
// to the C++ standard, offsetof() only works on POD types, and GCC
// enforces this requirement with a warning. In practice, this rule is
// unnecessarily strict; there is probably no compiler or platform on
// which the offsets of the direct fields of a class are non-constant.
// Fields inherited from superclasses *can* have non-constant offsets,
// but that's not what this macro will be used for.
#if defined(__clang__)
// For Clang we use __builtin_offsetof() and suppress the warning,
// to avoid Control Flow Integrity and UBSan vptr sanitizers from
// crashing while trying to validate the invalid reinterpet_casts.
#define GOOGLE_PROTOBUF_GENERATED_MESSAGE_FIELD_OFFSET(TYPE, FIELD) \
_Pragma("clang diagnostic push") \
_Pragma("clang diagnostic ignored \"-Winvalid-offsetof\"") \
__builtin_offsetof(TYPE, FIELD) \
_Pragma("clang diagnostic pop")
#else
// Note that we calculate relative to the pointer value 16 here since if we
// just use zero, GCC complains about dereferencing a NULL pointer. We
// choose 16 rather than some other number just in case the compiler would
// be confused by an unaligned pointer.
#define GOOGLE_PROTOBUF_GENERATED_MESSAGE_FIELD_OFFSET(TYPE, FIELD) \
static_cast<int>( \
reinterpret_cast<const char*>( \
&reinterpret_cast<const TYPE*>(16)->FIELD) - \
reinterpret_cast<const char*>(16))
#endif
#define PROTO2_GENERATED_DEFAULT_ONEOF_FIELD_OFFSET(ONEOF, FIELD) \
static_cast<int>( \
reinterpret_cast<const char*>(&(ONEOF->FIELD)) \
- reinterpret_cast<const char*>(ONEOF))
// There are some places in proto2 where dynamic_cast would be useful as an
// optimization. For example, take Message::MergeFrom(const Message& other).
// For a given generated message FooMessage, we generate these two methods:
// void MergeFrom(const FooMessage& other);
// void MergeFrom(const Message& other);
// The former method can be implemented directly in terms of FooMessage's
// inline accessors, but the latter method must work with the reflection
// interface. However, if the parameter to the latter method is actually of
// type FooMessage, then we'd like to be able to just call the other method
// as an optimization. So, we use dynamic_cast to check this.
//
// That said, dynamic_cast requires RTTI, which many people like to disable
// for performance and code size reasons. When RTTI is not available, we
// still need to produce correct results. So, in this case we have to fall
// back to using reflection, which is what we would have done anyway if the
// objects were not of the exact same class.
//
// dynamic_cast_if_available() implements this logic. If RTTI is
// enabled, it does a dynamic_cast. If RTTI is disabled, it just returns
// NULL.
//
// If you need to compile without RTTI, simply #define GOOGLE_PROTOBUF_NO_RTTI.
// On MSVC, this should be detected automatically.
template<typename To, typename From>
inline To dynamic_cast_if_available(From from) {
#if defined(GOOGLE_PROTOBUF_NO_RTTI) || defined(__GXX_RTTI) || \
(defined(_MSC_VER)&&!defined(_CPPRTTI))
return NULL;
#else
return dynamic_cast<To>(from);
#endif
}
// Tries to downcast this message to a generated message type.
// Returns NULL if this class is not an instance of T.
//
// This is like dynamic_cast_if_available, except it works even when
// dynamic_cast is not available by using Reflection. However it only works
// with Message objects.
//
// TODO(haberman): can we remove dynamic_cast_if_available in favor of this?
template <typename T>
T* DynamicCastToGenerated(const Message* from) {
// Compile-time assert that T is a generated type that has a
// default_instance() accessor, but avoid actually calling it.
const T&(*get_default_instance)() = &T::default_instance;
(void)get_default_instance;
// Compile-time assert that T is a subclass of google::protobuf::Message.
const Message* unused = static_cast<T*>(NULL);
(void)unused;
#if defined(GOOGLE_PROTOBUF_NO_RTTI) || defined(__GXX_RTTI) || \
(defined(_MSC_VER)&&!defined(_CPPRTTI))
bool ok = &T::default_instance() ==
from->GetReflection()->GetMessageFactory()->GetPrototype(
from->GetDescriptor());
return ok ? down_cast<T*>(from) : NULL;
#else
return dynamic_cast<T*>(from);
#endif
}
template <typename T>
T* DynamicCastToGenerated(Message* from) {
const Message* message_const = from;
return const_cast<T*>(DynamicCastToGenerated<const T>(message_const));
}
} // namespace internal
} // namespace protobuf
} // namespace google
#endif // GOOGLE_PROTOBUF_GENERATED_MESSAGE_REFLECTION_H__