FM / protobuf

/usr/include/google/protobuf

Name	Size	Mode	Actions
io/	-	0755	rm
stubs/	-	0755	rm
util/	-	0755	rm
any.h	6181	0644	edit dl rm
any.pb.h	17726	0644	edit dl rm
any.proto	5878	0644	edit dl rm
api.pb.h	64196	0644	edit dl rm
api.proto	7734	0644	edit dl rm
arena.h	31329	0644	edit dl rm
arenastring.h	14674	0644	edit dl rm
arena_impl.h	14316	0644	edit dl rm
descriptor.h	96357	0644	edit dl rm
descriptor.pb.h	587894	0644	edit dl rm
descriptor.proto	37986	0644	edit dl rm
descriptor_database.h	19379	0644	edit dl rm
duration.pb.h	9865	0644	edit dl rm
duration.proto	4888	0644	edit dl rm
dynamic_message.h	9986	0644	edit dl rm
empty.pb.h	7683	0644	edit dl rm
empty.proto	2422	0644	edit dl rm
extension_set.h	78461	0644	edit dl rm
extension_set_inl.h	12756	0644	edit dl rm
field_mask.pb.h	11825	0644	edit dl rm
field_mask.proto	8192	0644	edit dl rm
generated_enum_reflection.h	3954	0644	edit dl rm
generated_enum_util.h	3266	0644	edit dl rm
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generated_message_table_driven.h	12610	0644	edit dl rm
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has_bits.h	3528	0644	edit dl rm
implicit_weak_message.h	7014	0644	edit dl rm
inlined_string_field.h	9332	0644	edit dl rm
map.h	46287	0644	edit dl rm
map_entry.h	7276	0644	edit dl rm
map_entry_lite.h	26016	0644	edit dl rm
map_field.h	31208	0644	edit dl rm
map_field_inl.h	14512	0644	edit dl rm
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map_type_handler.h	39082	0644	edit dl rm
message.h	61613	0644	edit dl rm
message_lite.h	25964	0644	edit dl rm
metadata.h	1857	0644	edit dl rm
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parse_context.h	29812	0644	edit dl rm
port.h	2050	0644	edit dl rm
port_def.inc	17039	0644	edit dl rm
port_undef.inc	3498	0644	edit dl rm
reflection.h	22717	0644	edit dl rm
reflection_ops.h	3686	0644	edit dl rm
repeated_field.h	101032	0644	edit dl rm
service.h	13159	0644	edit dl rm
source_context.pb.h	12740	0644	edit dl rm
source_context.proto	2352	0644	edit dl rm
struct.pb.h	43629	0644	edit dl rm
struct.proto	3780	0644	edit dl rm
text_format.h	28948	0644	edit dl rm
timestamp.pb.h	9928	0644	edit dl rm
timestamp.proto	6200	0644	edit dl rm
type.pb.h	105722	0644	edit dl rm
type.proto	6129	0644	edit dl rm
unknown_field_set.h	14401	0644	edit dl rm
wire_format.h	17660	0644	edit dl rm
wire_format_lite.h	84033	0644	edit dl rm
wrappers.pb.h	61421	0644	edit dl rm
wrappers.proto	4035	0644	edit dl rm

Edit: /usr/include/google/protobuf/descriptor.h (96357B)

// 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 file contains classes which describe a type of protocol message.
// You can use a message's descriptor to learn at runtime what fields
// it contains and what the types of those fields are.  The Message
// interface also allows you to dynamically access and modify individual
// fields by passing the FieldDescriptor of the field you are interested
// in.
//
// Most users will not care about descriptors, because they will write
// code specific to certain protocol types and will simply use the classes
// generated by the protocol compiler directly.  Advanced users who want
// to operate on arbitrary types (not known at compile time) may want to
// read descriptors in order to learn about the contents of a message.
// A very small number of users will want to construct their own
// Descriptors, either because they are implementing Message manually or
// because they are writing something like the protocol compiler.
//
// For an example of how you might use descriptors, see the code example
// at the top of message.h.

#ifndef GOOGLE_PROTOBUF_DESCRIPTOR_H__
#define GOOGLE_PROTOBUF_DESCRIPTOR_H__

#include <map>
#include <memory>
#include <set>
#include <string>
#include <vector>

#include <google/protobuf/stubs/common.h>
#include <google/protobuf/stubs/mutex.h>
#include <google/protobuf/stubs/once.h>
#include <google/protobuf/port_def.inc>

// TYPE_BOOL is defined in the MacOS's ConditionalMacros.h.
#ifdef TYPE_BOOL
#undef TYPE_BOOL
#endif  // TYPE_BOOL

#ifdef SWIG
#define PROTOBUF_EXPORT
#endif

namespace google {
namespace protobuf {

// Defined in this file.
class Descriptor;
class FieldDescriptor;
class OneofDescriptor;
class EnumDescriptor;
class EnumValueDescriptor;
class ServiceDescriptor;
class MethodDescriptor;
class FileDescriptor;
class DescriptorDatabase;
class DescriptorPool;

// Defined in descriptor.proto
class DescriptorProto;
class DescriptorProto_ExtensionRange;
class FieldDescriptorProto;
class OneofDescriptorProto;
class EnumDescriptorProto;
class EnumValueDescriptorProto;
class ServiceDescriptorProto;
class MethodDescriptorProto;
class FileDescriptorProto;
class MessageOptions;
class FieldOptions;
class OneofOptions;
class EnumOptions;
class EnumValueOptions;
class ExtensionRangeOptions;
class ServiceOptions;
class MethodOptions;
class FileOptions;
class UninterpretedOption;
class SourceCodeInfo;

// Defined in message.h
class Message;
class Reflection;

// Defined in descriptor.cc
class DescriptorBuilder;
class FileDescriptorTables;
struct Symbol;

// Defined in unknown_field_set.h.
class UnknownField;

// Defined in command_line_interface.cc
namespace compiler {
class CommandLineInterface;
namespace cpp {
// Defined in helpers.h
class Formatter;
}  // namespace cpp
}  // namespace compiler

namespace descriptor_unittest {
class DescriptorTest;
}  // namespace descriptor_unittest

// Defined in printer.h
namespace io {
class Printer;
}  // namespace io

// NB, all indices are zero-based.
struct SourceLocation {
  int start_line;
  int end_line;
  int start_column;
  int end_column;

// Doc comments found at the source location.
  // See the comments in SourceCodeInfo.Location (descriptor.proto) for details.
  std::string leading_comments;
  std::string trailing_comments;
  std::vector<std::string> leading_detached_comments;
};

// Options when generating machine-parsable output from a descriptor with
// DebugString().
struct DebugStringOptions {
  // include original user comments as recorded in SourceLocation entries. N.B.
  // that this must be |false| by default: several other pieces of code (for
  // example, the C++ code generation for fields in the proto compiler) rely on
  // DebugString() output being unobstructed by user comments.
  bool include_comments;
  // If true, elide the braced body in the debug string.
  bool elide_group_body;
  bool elide_oneof_body;

DebugStringOptions()
      : include_comments(false),
        elide_group_body(false),
        elide_oneof_body(false) {
  }
};

// A class to handle the simplest cases of a lazily linked descriptor
// for a message type that isn't built at the time of cross linking,
// which is needed when a pool has lazily_build_dependencies_ set.
// Must be instantiated as mutable in a descriptor.
namespace internal {
class PROTOBUF_EXPORT LazyDescriptor {
 public:
  // Init function to be called at init time of a descriptor containing
  // a LazyDescriptor.
  void Init() {
    descriptor_ = nullptr;
    name_ = nullptr;
    once_ = nullptr;
    file_ = nullptr;
  }

// Sets the value of the descriptor if it is known during the descriptor
  // building process. Not thread safe, should only be called during the
  // descriptor build process. Should not be called after SetLazy has been
  // called.
  void Set(const Descriptor* descriptor);

// Sets the information needed to lazily cross link the descriptor at a later
  // time, SetLazy is not thread safe, should be called only once at descriptor
  // build time if the symbol wasn't found and building of the file containing
  // that type is delayed because lazily_build_dependencies_ is set on the pool.
  // Should not be called after Set() has been called.
  void SetLazy(const std::string& name, const FileDescriptor* file);

// Returns the current value of the descriptor, thread-safe. If SetLazy(...)
  // has been called, will do a one-time cross link of the type specified,
  // building the descriptor file that contains the type if necessary.
  inline const Descriptor* Get() {
    Once();
    return descriptor_;
  }

private:
  static void OnceStatic(LazyDescriptor* lazy);
  void OnceInternal();
  void Once();

const Descriptor* descriptor_;
  const std::string* name_;
  internal::once_flag* once_;
  const FileDescriptor* file_;
};
}  // namespace internal

// Describes a type of protocol message, or a particular group within a
// message.  To obtain the Descriptor for a given message object, call
// Message::GetDescriptor().  Generated message classes also have a
// static method called descriptor() which returns the type's descriptor.
// Use DescriptorPool to construct your own descriptors.
class PROTOBUF_EXPORT Descriptor {
 public:
  typedef DescriptorProto Proto;

// The name of the message type, not including its scope.
  const std::string& name() const;

// The fully-qualified name of the message type, scope delimited by
  // periods.  For example, message type "Foo" which is declared in package
  // "bar" has full name "bar.Foo".  If a type "Baz" is nested within
  // Foo, Baz's full_name is "bar.Foo.Baz".  To get only the part that
  // comes after the last '.', use name().
  const std::string& full_name() const;

// Index of this descriptor within the file or containing type's message
  // type array.
  int index() const;

// The .proto file in which this message type was defined.  Never nullptr.
  const FileDescriptor* file() const;

// If this Descriptor describes a nested type, this returns the type
  // in which it is nested.  Otherwise, returns nullptr.
  const Descriptor* containing_type() const;

// Get options for this message type.  These are specified in the .proto file
  // by placing lines like "option foo = 1234;" in the message definition.
  // Allowed options are defined by MessageOptions in descriptor.proto, and any
  // available extensions of that message.
  const MessageOptions& options() const;

// Write the contents of this Descriptor into the given DescriptorProto.
  // The target DescriptorProto must be clear before calling this; if it
  // isn't, the result may be garbage.
  void CopyTo(DescriptorProto* proto) const;

// Write the contents of this descriptor in a human-readable form. Output
  // will be suitable for re-parsing.
  std::string DebugString() const;

// Similar to DebugString(), but additionally takes options (e.g.,
  // include original user comments in output).
  std::string DebugStringWithOptions(const DebugStringOptions& options) const;

// Returns true if this is a placeholder for an unknown type. This will
  // only be the case if this descriptor comes from a DescriptorPool
  // with AllowUnknownDependencies() set.
  bool is_placeholder() const;

enum WellKnownType {
    WELLKNOWNTYPE_UNSPECIFIED,  // Not a well-known type.

// Wrapper types.
    WELLKNOWNTYPE_DOUBLEVALUE,  // google.protobuf.DoubleValue
    WELLKNOWNTYPE_FLOATVALUE,   // google.protobuf.FloatValue
    WELLKNOWNTYPE_INT64VALUE,   // google.protobuf.Int64Value
    WELLKNOWNTYPE_UINT64VALUE,  // google.protobuf.UInt64Value
    WELLKNOWNTYPE_INT32VALUE,   // google.protobuf.Int32Value
    WELLKNOWNTYPE_UINT32VALUE,  // google.protobuf.UInt32Value
    WELLKNOWNTYPE_STRINGVALUE,  // google.protobuf.StringValue
    WELLKNOWNTYPE_BYTESVALUE,   // google.protobuf.BytesValue
    WELLKNOWNTYPE_BOOLVALUE,    // google.protobuf.BoolValue

// Other well known types.
    WELLKNOWNTYPE_ANY,        // google.protobuf.Any
    WELLKNOWNTYPE_FIELDMASK,  // google.protobuf.FieldMask
    WELLKNOWNTYPE_DURATION,   // google.protobuf.Duration
    WELLKNOWNTYPE_TIMESTAMP,  // google.protobuf.Timestamp
    WELLKNOWNTYPE_VALUE,      // google.protobuf.Value
    WELLKNOWNTYPE_LISTVALUE,  // google.protobuf.ListValue
    WELLKNOWNTYPE_STRUCT,     // google.protobuf.Struct

// New well-known types may be added in the future.
    // Please make sure any switch() statements have a 'default' case.
    __WELLKNOWNTYPE__DO_NOT_USE__ADD_DEFAULT_INSTEAD__,
  };

WellKnownType well_known_type() const;

// Field stuff -----------------------------------------------------

// The number of fields in this message type.
  int field_count() const;
  // Gets a field by index, where 0 <= index < field_count().
  // These are returned in the order they were defined in the .proto file.
  const FieldDescriptor* field(int index) const;

// Looks up a field by declared tag number.  Returns nullptr if no such field
  // exists.
  const FieldDescriptor* FindFieldByNumber(int number) const;
  // Looks up a field by name.  Returns nullptr if no such field exists.
  const FieldDescriptor* FindFieldByName(const std::string& name) const;

// Looks up a field by lowercased name (as returned by lowercase_name()).
  // This lookup may be ambiguous if multiple field names differ only by case,
  // in which case the field returned is chosen arbitrarily from the matches.
  const FieldDescriptor* FindFieldByLowercaseName(
      const std::string& lowercase_name) const;

// Looks up a field by camel-case name (as returned by camelcase_name()).
  // This lookup may be ambiguous if multiple field names differ in a way that
  // leads them to have identical camel-case names, in which case the field
  // returned is chosen arbitrarily from the matches.
  const FieldDescriptor* FindFieldByCamelcaseName(
      const std::string& camelcase_name) const;

// The number of oneofs in this message type.
  int oneof_decl_count() const;
  // The number of oneofs in this message type, excluding synthetic oneofs.
  // Real oneofs always come first, so iterating up to real_oneof_decl_cout()
  // will yield all real oneofs.
  int real_oneof_decl_count() const;
  // Get a oneof by index, where 0 <= index < oneof_decl_count().
  // These are returned in the order they were defined in the .proto file.
  const OneofDescriptor* oneof_decl(int index) const;

// Looks up a oneof by name.  Returns nullptr if no such oneof exists.
  const OneofDescriptor* FindOneofByName(const std::string& name) const;

// Nested type stuff -----------------------------------------------

// The number of nested types in this message type.
  int nested_type_count() const;
  // Gets a nested type by index, where 0 <= index < nested_type_count().
  // These are returned in the order they were defined in the .proto file.
  const Descriptor* nested_type(int index) const;

// Looks up a nested type by name.  Returns nullptr if no such nested type
  // exists.
  const Descriptor* FindNestedTypeByName(const std::string& name) const;

// Enum stuff ------------------------------------------------------

// The number of enum types in this message type.
  int enum_type_count() const;
  // Gets an enum type by index, where 0 <= index < enum_type_count().
  // These are returned in the order they were defined in the .proto file.
  const EnumDescriptor* enum_type(int index) const;

// Looks up an enum type by name.  Returns nullptr if no such enum type
  // exists.
  const EnumDescriptor* FindEnumTypeByName(const std::string& name) const;

// Looks up an enum value by name, among all enum types in this message.
  // Returns nullptr if no such value exists.
  const EnumValueDescriptor* FindEnumValueByName(const std::string& name) const;

// Extensions ------------------------------------------------------

// A range of field numbers which are designated for third-party
  // extensions.
  struct ExtensionRange {
    typedef DescriptorProto_ExtensionRange Proto;

typedef ExtensionRangeOptions OptionsType;

// See Descriptor::CopyTo().
    void CopyTo(DescriptorProto_ExtensionRange* proto) const;

int start;  // inclusive
    int end;    // exclusive

const ExtensionRangeOptions* options_;
  };

// The number of extension ranges in this message type.
  int extension_range_count() const;
  // Gets an extension range by index, where 0 <= index <
  // extension_range_count(). These are returned in the order they were defined
  // in the .proto file.
  const ExtensionRange* extension_range(int index) const;

// Returns true if the number is in one of the extension ranges.
  bool IsExtensionNumber(int number) const;

// Returns nullptr if no extension range contains the given number.
  const ExtensionRange* FindExtensionRangeContainingNumber(int number) const;

// The number of extensions defined nested within this message type's scope.
  // See doc:
  // https://developers.google.com/protocol-buffers/docs/proto#nested-extensions
  //
  // Note that the extensions may be extending *other* messages.
  //
  // For example:
  // message M1 {
  //   extensions 1 to max;
  // }
  //
  // message M2 {
  //   extend M1 {
  //     optional int32 foo = 1;
  //   }
  // }
  //
  // In this case,
  // DescriptorPool::generated_pool()
  //     ->FindMessageTypeByName("M2")
  //     ->extension(0)
  // will return "foo", even though "foo" is an extension of M1.
  // To find all known extensions of a given message, instead use
  // DescriptorPool::FindAllExtensions.
  int extension_count() const;
  // Get an extension by index, where 0 <= index < extension_count().
  // These are returned in the order they were defined in the .proto file.
  const FieldDescriptor* extension(int index) const;

// Looks up a named extension (which extends some *other* message type)
  // defined within this message type's scope.
  const FieldDescriptor* FindExtensionByName(const std::string& name) const;

// Similar to FindFieldByLowercaseName(), but finds extensions defined within
  // this message type's scope.
  const FieldDescriptor* FindExtensionByLowercaseName(
      const std::string& name) const;

// Similar to FindFieldByCamelcaseName(), but finds extensions defined within
  // this message type's scope.
  const FieldDescriptor* FindExtensionByCamelcaseName(
      const std::string& name) const;

// Reserved fields -------------------------------------------------

// A range of reserved field numbers.
  struct ReservedRange {
    int start;  // inclusive
    int end;    // exclusive
  };

// The number of reserved ranges in this message type.
  int reserved_range_count() const;
  // Gets an reserved range by index, where 0 <= index <
  // reserved_range_count(). These are returned in the order they were defined
  // in the .proto file.
  const ReservedRange* reserved_range(int index) const;

// Returns true if the number is in one of the reserved ranges.
  bool IsReservedNumber(int number) const;

// Returns nullptr if no reserved range contains the given number.
  const ReservedRange* FindReservedRangeContainingNumber(int number) const;

// The number of reserved field names in this message type.
  int reserved_name_count() const;

// Gets a reserved name by index, where 0 <= index < reserved_name_count().
  const std::string& reserved_name(int index) const;

// Returns true if the field name is reserved.
  bool IsReservedName(const std::string& name) const;

// Source Location ---------------------------------------------------

// Updates |*out_location| to the source location of the complete
  // extent of this message declaration.  Returns false and leaves
  // |*out_location| unchanged iff location information was not available.
  bool GetSourceLocation(SourceLocation* out_location) const;

// Maps --------------------------------------------------------------

// Returns the FieldDescriptor for the "key" field. If this isn't a map entry
  // field, returns nullptr.
  const FieldDescriptor* map_key() const;

// Returns the FieldDescriptor for the "value" field. If this isn't a map
  // entry field, returns nullptr.
  const FieldDescriptor* map_value() const;

private:
  typedef MessageOptions OptionsType;

// Allows tests to test CopyTo(proto, true).
  friend class descriptor_unittest::DescriptorTest;

// Allows access to GetLocationPath for annotations.
  friend class io::Printer;
  friend class compiler::cpp::Formatter;

// Fill the json_name field of FieldDescriptorProto.
  void CopyJsonNameTo(DescriptorProto* proto) const;

// Internal version of DebugString; controls the level of indenting for
  // correct depth. Takes |options| to control debug-string options, and
  // |include_opening_clause| to indicate whether the "message ... " part of the
  // clause has already been generated (this varies depending on context).
  void DebugString(int depth, std::string* contents,
                   const DebugStringOptions& options,
                   bool include_opening_clause) const;

// Walks up the descriptor tree to generate the source location path
  // to this descriptor from the file root.
  void GetLocationPath(std::vector<int>* output) const;

const std::string* name_;
  const std::string* full_name_;
  const FileDescriptor* file_;
  const Descriptor* containing_type_;
  const MessageOptions* options_;

// These arrays are separated from their sizes to minimize padding on 64-bit.
  FieldDescriptor* fields_;
  OneofDescriptor* oneof_decls_;
  Descriptor* nested_types_;
  EnumDescriptor* enum_types_;
  ExtensionRange* extension_ranges_;
  FieldDescriptor* extensions_;
  ReservedRange* reserved_ranges_;
  const std::string** reserved_names_;

int field_count_;
  int oneof_decl_count_;
  int real_oneof_decl_count_;
  int nested_type_count_;
  int enum_type_count_;
  int extension_range_count_;
  int extension_count_;
  int reserved_range_count_;
  int reserved_name_count_;

// True if this is a placeholder for an unknown type.
  bool is_placeholder_;
  // True if this is a placeholder and the type name wasn't fully-qualified.
  bool is_unqualified_placeholder_;
  // Well known type.  Stored as char to conserve space.
  char well_known_type_;

// IMPORTANT:  If you add a new field, make sure to search for all instances
  // of Allocate<Descriptor>() and AllocateArray<Descriptor>() in descriptor.cc
  // and update them to initialize the field.

// Must be constructed using DescriptorPool.
  Descriptor() {}
  friend class DescriptorBuilder;
  friend class DescriptorPool;
  friend class EnumDescriptor;
  friend class FieldDescriptor;
  friend class OneofDescriptor;
  friend class MethodDescriptor;
  friend class FileDescriptor;
  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(Descriptor);
};

// Describes a single field of a message.  To get the descriptor for a given
// field, first get the Descriptor for the message in which it is defined,
// then call Descriptor::FindFieldByName().  To get a FieldDescriptor for
// an extension, do one of the following:
// - Get the Descriptor or FileDescriptor for its containing scope, then
//   call Descriptor::FindExtensionByName() or
//   FileDescriptor::FindExtensionByName().
// - Given a DescriptorPool, call DescriptorPool::FindExtensionByNumber() or
//   DescriptorPool::FindExtensionByPrintableName().
// Use DescriptorPool to construct your own descriptors.
class PROTOBUF_EXPORT FieldDescriptor {
 public:
  typedef FieldDescriptorProto Proto;

// Identifies a field type.  0 is reserved for errors.  The order is weird
  // for historical reasons.  Types 12 and up are new in proto2.
  enum Type {
    TYPE_DOUBLE = 1,    // double, exactly eight bytes on the wire.
    TYPE_FLOAT = 2,     // float, exactly four bytes on the wire.
    TYPE_INT64 = 3,     // int64, varint on the wire.  Negative numbers
                        // take 10 bytes.  Use TYPE_SINT64 if negative
                        // values are likely.
    TYPE_UINT64 = 4,    // uint64, varint on the wire.
    TYPE_INT32 = 5,     // int32, varint on the wire.  Negative numbers
                        // take 10 bytes.  Use TYPE_SINT32 if negative
                        // values are likely.
    TYPE_FIXED64 = 6,   // uint64, exactly eight bytes on the wire.
    TYPE_FIXED32 = 7,   // uint32, exactly four bytes on the wire.
    TYPE_BOOL = 8,      // bool, varint on the wire.
    TYPE_STRING = 9,    // UTF-8 text.
    TYPE_GROUP = 10,    // Tag-delimited message.  Deprecated.
    TYPE_MESSAGE = 11,  // Length-delimited message.

TYPE_BYTES = 12,     // Arbitrary byte array.
    TYPE_UINT32 = 13,    // uint32, varint on the wire
    TYPE_ENUM = 14,      // Enum, varint on the wire
    TYPE_SFIXED32 = 15,  // int32, exactly four bytes on the wire
    TYPE_SFIXED64 = 16,  // int64, exactly eight bytes on the wire
    TYPE_SINT32 = 17,    // int32, ZigZag-encoded varint on the wire
    TYPE_SINT64 = 18,    // int64, ZigZag-encoded varint on the wire

MAX_TYPE = 18,  // Constant useful for defining lookup tables
                    // indexed by Type.
  };

// Specifies the C++ data type used to represent the field.  There is a
  // fixed mapping from Type to CppType where each Type maps to exactly one
  // CppType.  0 is reserved for errors.
  enum CppType {
    CPPTYPE_INT32 = 1,     // TYPE_INT32, TYPE_SINT32, TYPE_SFIXED32
    CPPTYPE_INT64 = 2,     // TYPE_INT64, TYPE_SINT64, TYPE_SFIXED64
    CPPTYPE_UINT32 = 3,    // TYPE_UINT32, TYPE_FIXED32
    CPPTYPE_UINT64 = 4,    // TYPE_UINT64, TYPE_FIXED64
    CPPTYPE_DOUBLE = 5,    // TYPE_DOUBLE
    CPPTYPE_FLOAT = 6,     // TYPE_FLOAT
    CPPTYPE_BOOL = 7,      // TYPE_BOOL
    CPPTYPE_ENUM = 8,      // TYPE_ENUM
    CPPTYPE_STRING = 9,    // TYPE_STRING, TYPE_BYTES
    CPPTYPE_MESSAGE = 10,  // TYPE_MESSAGE, TYPE_GROUP

MAX_CPPTYPE = 10,  // Constant useful for defining lookup tables
                       // indexed by CppType.
  };

// Identifies whether the field is optional, required, or repeated.  0 is
  // reserved for errors.
  enum Label {
    LABEL_OPTIONAL = 1,  // optional
    LABEL_REQUIRED = 2,  // required
    LABEL_REPEATED = 3,  // repeated

MAX_LABEL = 3,  // Constant useful for defining lookup tables
                    // indexed by Label.
  };

// Valid field numbers are positive integers up to kMaxNumber.
  static const int kMaxNumber = (1 << 29) - 1;

// First field number reserved for the protocol buffer library implementation.
  // Users may not declare fields that use reserved numbers.
  static const int kFirstReservedNumber = 19000;
  // Last field number reserved for the protocol buffer library implementation.
  // Users may not declare fields that use reserved numbers.
  static const int kLastReservedNumber = 19999;

const std::string& name() const;  // Name of this field within the message.
  const std::string& full_name() const;  // Fully-qualified name of the field.
  const std::string& json_name() const;  // JSON name of this field.
  const FileDescriptor* file() const;  // File in which this field was defined.
  bool is_extension() const;           // Is this an extension field?
  int number() const;                  // Declared tag number.

// Same as name() except converted to lower-case.  This (and especially the
  // FindFieldByLowercaseName() method) can be useful when parsing formats
  // which prefer to use lowercase naming style.  (Although, technically
  // field names should be lowercased anyway according to the protobuf style
  // guide, so this only makes a difference when dealing with old .proto files
  // which do not follow the guide.)
  const std::string& lowercase_name() const;

// Same as name() except converted to camel-case.  In this conversion, any
  // time an underscore appears in the name, it is removed and the next
  // letter is capitalized.  Furthermore, the first letter of the name is
  // lower-cased.  Examples:
  //   FooBar -> fooBar
  //   foo_bar -> fooBar
  //   fooBar -> fooBar
  // This (and especially the FindFieldByCamelcaseName() method) can be useful
  // when parsing formats which prefer to use camel-case naming style.
  const std::string& camelcase_name() const;

Type type() const;                  // Declared type of this field.
  const char* type_name() const;      // Name of the declared type.
  CppType cpp_type() const;           // C++ type of this field.
  const char* cpp_type_name() const;  // Name of the C++ type.
  Label label() const;                // optional/required/repeated

bool is_required() const;  // shorthand for label() == LABEL_REQUIRED
  bool is_optional() const;  // shorthand for label() == LABEL_OPTIONAL
  bool is_repeated() const;  // shorthand for label() == LABEL_REPEATED
  bool is_packable() const;  // shorthand for is_repeated() &&
                             //               IsTypePackable(type())
  bool is_packed() const;    // shorthand for is_packable() &&
                             //               options().packed()
  bool is_map() const;       // shorthand for type() == TYPE_MESSAGE &&
                             // message_type()->options().map_entry()

// Returns true if this field was syntactically written with "optional" in the
  // .proto file. Excludes singular proto3 fields that do not have a label.
  bool has_optional_keyword() const;

// Returns true if this field tracks presence, ie. does the field
  // distinguish between "unset" and "present with default value."
  // This includes required, optional, and oneof fields. It excludes maps,
  // repeated fields, and singular proto3 fields without "optional".
  //
  // For fields where has_presence() == true, the return value of
  // Reflection::HasField() is semantically meaningful.
  bool has_presence() const;

// Index of this field within the message's field array, or the file or
  // extension scope's extensions array.
  int index() const;

// Does this field have an explicitly-declared default value?
  bool has_default_value() const;

// Whether the user has specified the json_name field option in the .proto
  // file.
  bool has_json_name() const;

// Get the field default value if cpp_type() == CPPTYPE_INT32.  If no
  // explicit default was defined, the default is 0.
  int32 default_value_int32() const;
  // Get the field default value if cpp_type() == CPPTYPE_INT64.  If no
  // explicit default was defined, the default is 0.
  int64 default_value_int64() const;
  // Get the field default value if cpp_type() == CPPTYPE_UINT32.  If no
  // explicit default was defined, the default is 0.
  uint32 default_value_uint32() const;
  // Get the field default value if cpp_type() == CPPTYPE_UINT64.  If no
  // explicit default was defined, the default is 0.
  uint64 default_value_uint64() const;
  // Get the field default value if cpp_type() == CPPTYPE_FLOAT.  If no
  // explicit default was defined, the default is 0.0.
  float default_value_float() const;
  // Get the field default value if cpp_type() == CPPTYPE_DOUBLE.  If no
  // explicit default was defined, the default is 0.0.
  double default_value_double() const;
  // Get the field default value if cpp_type() == CPPTYPE_BOOL.  If no
  // explicit default was defined, the default is false.
  bool default_value_bool() const;
  // Get the field default value if cpp_type() == CPPTYPE_ENUM.  If no
  // explicit default was defined, the default is the first value defined
  // in the enum type (all enum types are required to have at least one value).
  // This never returns nullptr.
  const EnumValueDescriptor* default_value_enum() const;
  // Get the field default value if cpp_type() == CPPTYPE_STRING.  If no
  // explicit default was defined, the default is the empty string.
  const std::string& default_value_string() const;

// The Descriptor for the message of which this is a field.  For extensions,
  // this is the extended type.  Never nullptr.
  const Descriptor* containing_type() const;

// If the field is a member of a oneof, this is the one, otherwise this is
  // nullptr.
  const OneofDescriptor* containing_oneof() const;

// If the field is a member of a non-synthetic oneof, returns the descriptor
  // for the oneof, otherwise returns nullptr.
  const OneofDescriptor* real_containing_oneof() const;

// If the field is a member of a oneof, returns the index in that oneof.
  int index_in_oneof() const;

// An extension may be declared within the scope of another message.  If this
  // field is an extension (is_extension() is true), then extension_scope()
  // returns that message, or nullptr if the extension was declared at global
  // scope.  If this is not an extension, extension_scope() is undefined (may
  // assert-fail).
  const Descriptor* extension_scope() const;

// If type is TYPE_MESSAGE or TYPE_GROUP, returns a descriptor for the
  // message or the group type.  Otherwise, returns null.
  const Descriptor* message_type() const;
  // If type is TYPE_ENUM, returns a descriptor for the enum.  Otherwise,
  // returns null.
  const EnumDescriptor* enum_type() const;

// Get the FieldOptions for this field.  This includes things listed in
  // square brackets after the field definition.  E.g., the field:
  //   optional string text = 1 [ctype=CORD];
  // has the "ctype" option set.  Allowed options are defined by FieldOptions in
  // descriptor.proto, and any available extensions of that message.
  const FieldOptions& options() const;

// See Descriptor::CopyTo().
  void CopyTo(FieldDescriptorProto* proto) const;

// See Descriptor::DebugString().
  std::string DebugString() const;

// See Descriptor::DebugStringWithOptions().
  std::string DebugStringWithOptions(const DebugStringOptions& options) const;

// Helper method to get the CppType for a particular Type.
  static CppType TypeToCppType(Type type);

// Helper method to get the name of a Type.
  static const char* TypeName(Type type);

// Helper method to get the name of a CppType.
  static const char* CppTypeName(CppType cpp_type);

// Return true iff [packed = true] is valid for fields of this type.
  static inline bool IsTypePackable(Type field_type);

// Returns full_name() except if the field is a MessageSet extension,
  // in which case it returns the full_name() of the containing message type
  // for backwards compatibility with proto1.
  //
  // A MessageSet extension is defined as an optional message extension
  // whose containing type has the message_set_wire_format option set.
  // This should be true of extensions of google.protobuf.bridge.MessageSet;
  // by convention, such extensions are named "message_set_extension".
  //
  // The opposite operation (looking up an extension's FieldDescriptor given
  // its printable name) can be accomplished with
  //     message->file()->pool()->FindExtensionByPrintableName(message, name)
  // where the extension extends "message".
  const std::string& PrintableNameForExtension() const;

// Source Location ---------------------------------------------------

// Updates |*out_location| to the source location of the complete
  // extent of this field declaration.  Returns false and leaves
  // |*out_location| unchanged iff location information was not available.
  bool GetSourceLocation(SourceLocation* out_location) const;

private:
  typedef FieldOptions OptionsType;

// Allows access to GetLocationPath for annotations.
  friend class io::Printer;
  friend class compiler::cpp::Formatter;

// Fill the json_name field of FieldDescriptorProto.
  void CopyJsonNameTo(FieldDescriptorProto* proto) const;

// See Descriptor::DebugString().
  void DebugString(int depth, std::string* contents,
                   const DebugStringOptions& options) const;

// formats the default value appropriately and returns it as a string.
  // Must have a default value to call this. If quote_string_type is true, then
  // types of CPPTYPE_STRING whill be surrounded by quotes and CEscaped.
  std::string DefaultValueAsString(bool quote_string_type) const;

// Helper function that returns the field type name for DebugString.
  std::string FieldTypeNameDebugString() const;

// Walks up the descriptor tree to generate the source location path
  // to this descriptor from the file root.
  void GetLocationPath(std::vector<int>* output) const;

// Returns true if this is a map message type.
  bool is_map_message_type() const;

const std::string* name_;
  const std::string* full_name_;
  const std::string* lowercase_name_;
  const std::string* camelcase_name_;
  // If has_json_name_ is true, it's the value specified by the user.
  // Otherwise, it has the same value as camelcase_name_.
  const std::string* json_name_;
  const FileDescriptor* file_;
  internal::once_flag* type_once_;
  static void TypeOnceInit(const FieldDescriptor* to_init);
  void InternalTypeOnceInit() const;
  mutable Type type_;
  Label label_;
  bool has_default_value_;
  bool proto3_optional_;
  // Whether the user has specified the json_name field option in the .proto
  // file.
  bool has_json_name_;
  bool is_extension_;
  int number_;
  int index_in_oneof_;
  const Descriptor* containing_type_;
  const OneofDescriptor* containing_oneof_;
  const Descriptor* extension_scope_;
  mutable const Descriptor* message_type_;
  mutable const EnumDescriptor* enum_type_;
  const FieldOptions* options_;
  const std::string* type_name_;
  const std::string* default_value_enum_name_;
  // IMPORTANT:  If you add a new field, make sure to search for all instances
  // of Allocate<FieldDescriptor>() and AllocateArray<FieldDescriptor>() in
  // descriptor.cc and update them to initialize the field.

union {
    int32 default_value_int32_;
    int64 default_value_int64_;
    uint32 default_value_uint32_;
    uint64 default_value_uint64_;
    float default_value_float_;
    double default_value_double_;
    bool default_value_bool_;

mutable const EnumValueDescriptor* default_value_enum_;
    const std::string* default_value_string_;
  };

static const CppType kTypeToCppTypeMap[MAX_TYPE + 1];

static const char* const kTypeToName[MAX_TYPE + 1];

static const char* const kCppTypeToName[MAX_CPPTYPE + 1];

static const char* const kLabelToName[MAX_LABEL + 1];

// Must be constructed using DescriptorPool.
  FieldDescriptor() {}
  friend class DescriptorBuilder;
  friend class FileDescriptor;
  friend class Descriptor;
  friend class OneofDescriptor;
  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(FieldDescriptor);
};

// Describes a oneof defined in a message type.
class PROTOBUF_EXPORT OneofDescriptor {
 public:
  typedef OneofDescriptorProto Proto;

const std::string& name() const;       // Name of this oneof.
  const std::string& full_name() const;  // Fully-qualified name of the oneof.

// Index of this oneof within the message's oneof array.
  int index() const;

// Returns whether this oneof was inserted by the compiler to wrap a proto3
  // optional field. If this returns true, code generators should *not* emit it.
  bool is_synthetic() const;

// The .proto file in which this oneof was defined.  Never nullptr.
  const FileDescriptor* file() const;
  // The Descriptor for the message containing this oneof.
  const Descriptor* containing_type() const;

// The number of (non-extension) fields which are members of this oneof.
  int field_count() const;
  // Get a member of this oneof, in the order in which they were declared in the
  // .proto file.  Does not include extensions.
  const FieldDescriptor* field(int index) const;

const OneofOptions& options() const;

// See Descriptor::CopyTo().
  void CopyTo(OneofDescriptorProto* proto) const;

// See Descriptor::DebugString().
  std::string DebugString() const;

// See Descriptor::DebugStringWithOptions().
  std::string DebugStringWithOptions(const DebugStringOptions& options) const;

// Source Location ---------------------------------------------------

// Updates |*out_location| to the source location of the complete
  // extent of this oneof declaration.  Returns false and leaves
  // |*out_location| unchanged iff location information was not available.
  bool GetSourceLocation(SourceLocation* out_location) const;

private:
  typedef OneofOptions OptionsType;

// Allows access to GetLocationPath for annotations.
  friend class io::Printer;
  friend class compiler::cpp::Formatter;

// See Descriptor::DebugString().
  void DebugString(int depth, std::string* contents,
                   const DebugStringOptions& options) const;

// Walks up the descriptor tree to generate the source location path
  // to this descriptor from the file root.
  void GetLocationPath(std::vector<int>* output) const;

const std::string* name_;
  const std::string* full_name_;
  const Descriptor* containing_type_;
  int field_count_;
  const FieldDescriptor** fields_;
  const OneofOptions* options_;

// IMPORTANT:  If you add a new field, make sure to search for all instances
  // of Allocate<OneofDescriptor>() and AllocateArray<OneofDescriptor>()
  // in descriptor.cc and update them to initialize the field.

// Must be constructed using DescriptorPool.
  OneofDescriptor() {}
  friend class DescriptorBuilder;
  friend class Descriptor;
  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(OneofDescriptor);
};

// Describes an enum type defined in a .proto file.  To get the EnumDescriptor
// for a generated enum type, call TypeName_descriptor().  Use DescriptorPool
// to construct your own descriptors.
class PROTOBUF_EXPORT EnumDescriptor {
 public:
  typedef EnumDescriptorProto Proto;

// The name of this enum type in the containing scope.
  const std::string& name() const;

// The fully-qualified name of the enum type, scope delimited by periods.
  const std::string& full_name() const;

// Index of this enum within the file or containing message's enum array.
  int index() const;

// The .proto file in which this enum type was defined.  Never nullptr.
  const FileDescriptor* file() const;

// The number of values for this EnumDescriptor.  Guaranteed to be greater
  // than zero.
  int value_count() const;
  // Gets a value by index, where 0 <= index < value_count().
  // These are returned in the order they were defined in the .proto file.
  const EnumValueDescriptor* value(int index) const;

// Looks up a value by name.  Returns nullptr if no such value exists.
  const EnumValueDescriptor* FindValueByName(const std::string& name) const;
  // Looks up a value by number.  Returns nullptr if no such value exists.  If
  // multiple values have this number, the first one defined is returned.
  const EnumValueDescriptor* FindValueByNumber(int number) const;

// If this enum type is nested in a message type, this is that message type.
  // Otherwise, nullptr.
  const Descriptor* containing_type() const;

// Get options for this enum type.  These are specified in the .proto file by
  // placing lines like "option foo = 1234;" in the enum definition.  Allowed
  // options are defined by EnumOptions in descriptor.proto, and any available
  // extensions of that message.
  const EnumOptions& options() const;

// See Descriptor::CopyTo().
  void CopyTo(EnumDescriptorProto* proto) const;

// See Descriptor::DebugString().
  std::string DebugString() const;

// See Descriptor::DebugStringWithOptions().
  std::string DebugStringWithOptions(const DebugStringOptions& options) const;

// Returns true if this is a placeholder for an unknown enum. This will
  // only be the case if this descriptor comes from a DescriptorPool
  // with AllowUnknownDependencies() set.
  bool is_placeholder() const;

// Reserved fields -------------------------------------------------

// A range of reserved field numbers.
  struct ReservedRange {
    int start;  // inclusive
    int end;    // inclusive
  };

// Returns true if the number is in one of the reserved ranges.
  bool IsReservedNumber(int number) const;

// Returns nullptr if no reserved range contains the given number.
  const EnumDescriptor::ReservedRange* FindReservedRangeContainingNumber(
      int number) const;

// The number of reserved field names in this message type.
  int reserved_name_count() const;

// Gets a reserved name by index, where 0 <= index < reserved_name_count().
  const std::string& reserved_name(int index) const;

// Returns true if the field name is reserved.
  bool IsReservedName(const std::string& name) const;

// Source Location ---------------------------------------------------

// Updates |*out_location| to the source location of the complete
  // extent of this enum declaration.  Returns false and leaves
  // |*out_location| unchanged iff location information was not available.
  bool GetSourceLocation(SourceLocation* out_location) const;

private:
  typedef EnumOptions OptionsType;

// Allows access to GetLocationPath for annotations.
  friend class io::Printer;
  friend class compiler::cpp::Formatter;

// Looks up a value by number.  If the value does not exist, dynamically
  // creates a new EnumValueDescriptor for that value, assuming that it was
  // unknown. If a new descriptor is created, this is done in a thread-safe way,
  // and future calls will return the same value descriptor pointer.
  //
  // This is private but is used by Reflection (which is friended below) to
  // return a valid EnumValueDescriptor from GetEnum() when this feature is
  // enabled.
  const EnumValueDescriptor* FindValueByNumberCreatingIfUnknown(
      int number) const;

// See Descriptor::DebugString().
  void DebugString(int depth, std::string* contents,
                   const DebugStringOptions& options) const;

// Walks up the descriptor tree to generate the source location path
  // to this descriptor from the file root.
  void GetLocationPath(std::vector<int>* output) const;

const std::string* name_;
  const std::string* full_name_;
  const FileDescriptor* file_;
  const Descriptor* containing_type_;
  const EnumOptions* options_;

// True if this is a placeholder for an unknown type.
  bool is_placeholder_;
  // True if this is a placeholder and the type name wasn't fully-qualified.
  bool is_unqualified_placeholder_;

int value_count_;
  EnumValueDescriptor* values_;

int reserved_range_count_;
  int reserved_name_count_;
  EnumDescriptor::ReservedRange* reserved_ranges_;
  const std::string** reserved_names_;

// IMPORTANT:  If you add a new field, make sure to search for all instances
  // of Allocate<EnumDescriptor>() and AllocateArray<EnumDescriptor>() in
  // descriptor.cc and update them to initialize the field.

// Must be constructed using DescriptorPool.
  EnumDescriptor() {}
  friend class DescriptorBuilder;
  friend class Descriptor;
  friend class FieldDescriptor;
  friend class EnumValueDescriptor;
  friend class FileDescriptor;
  friend class DescriptorPool;
  friend class Reflection;
  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(EnumDescriptor);
};

// Describes an individual enum constant of a particular type.  To get the
// EnumValueDescriptor for a given enum value, first get the EnumDescriptor
// for its type, then use EnumDescriptor::FindValueByName() or
// EnumDescriptor::FindValueByNumber().  Use DescriptorPool to construct
// your own descriptors.
class PROTOBUF_EXPORT EnumValueDescriptor {
 public:
  typedef EnumValueDescriptorProto Proto;

const std::string& name() const;  // Name of this enum constant.
  int index() const;                // Index within the enums's Descriptor.
  int number() const;               // Numeric value of this enum constant.

// The full_name of an enum value is a sibling symbol of the enum type.
  // e.g. the full name of FieldDescriptorProto::TYPE_INT32 is actually
  // "google.protobuf.FieldDescriptorProto.TYPE_INT32", NOT
  // "google.protobuf.FieldDescriptorProto.Type.TYPE_INT32".  This is to conform
  // with C++ scoping rules for enums.
  const std::string& full_name() const;

// The .proto file in which this value was defined.  Never nullptr.
  const FileDescriptor* file() const;
  // The type of this value.  Never nullptr.
  const EnumDescriptor* type() const;

// Get options for this enum value.  These are specified in the .proto file by
  // adding text like "[foo = 1234]" after an enum value definition.  Allowed
  // options are defined by EnumValueOptions in descriptor.proto, and any
  // available extensions of that message.
  const EnumValueOptions& options() const;

// See Descriptor::CopyTo().
  void CopyTo(EnumValueDescriptorProto* proto) const;

// See Descriptor::DebugString().
  std::string DebugString() const;

// See Descriptor::DebugStringWithOptions().
  std::string DebugStringWithOptions(const DebugStringOptions& options) const;

// Source Location ---------------------------------------------------

// Updates |*out_location| to the source location of the complete
  // extent of this enum value declaration.  Returns false and leaves
  // |*out_location| unchanged iff location information was not available.
  bool GetSourceLocation(SourceLocation* out_location) const;

private:
  typedef EnumValueOptions OptionsType;

// Allows access to GetLocationPath for annotations.
  friend class io::Printer;
  friend class compiler::cpp::Formatter;

// See Descriptor::DebugString().
  void DebugString(int depth, std::string* contents,
                   const DebugStringOptions& options) const;

// Walks up the descriptor tree to generate the source location path
  // to this descriptor from the file root.
  void GetLocationPath(std::vector<int>* output) const;

const std::string* name_;
  const std::string* full_name_;
  int number_;
  const EnumDescriptor* type_;
  const EnumValueOptions* options_;
  // IMPORTANT:  If you add a new field, make sure to search for all instances
  // of Allocate<EnumValueDescriptor>() and AllocateArray<EnumValueDescriptor>()
  // in descriptor.cc and update them to initialize the field.

// Must be constructed using DescriptorPool.
  EnumValueDescriptor() {}
  friend class DescriptorBuilder;
  friend class EnumDescriptor;
  friend class DescriptorPool;
  friend class FileDescriptorTables;
  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(EnumValueDescriptor);
};

// Describes an RPC service. Use DescriptorPool to construct your own
// descriptors.
class PROTOBUF_EXPORT ServiceDescriptor {
 public:
  typedef ServiceDescriptorProto Proto;

// The name of the service, not including its containing scope.
  const std::string& name() const;
  // The fully-qualified name of the service, scope delimited by periods.
  const std::string& full_name() const;
  // Index of this service within the file's services array.
  int index() const;

// The .proto file in which this service was defined.  Never nullptr.
  const FileDescriptor* file() const;

// Get options for this service type.  These are specified in the .proto file
  // by placing lines like "option foo = 1234;" in the service definition.
  // Allowed options are defined by ServiceOptions in descriptor.proto, and any
  // available extensions of that message.
  const ServiceOptions& options() const;

// The number of methods this service defines.
  int method_count() const;
  // Gets a MethodDescriptor by index, where 0 <= index < method_count().
  // These are returned in the order they were defined in the .proto file.
  const MethodDescriptor* method(int index) const;

// Look up a MethodDescriptor by name.
  const MethodDescriptor* FindMethodByName(const std::string& name) const;
  // See Descriptor::CopyTo().
  void CopyTo(ServiceDescriptorProto* proto) const;

// See Descriptor::DebugString().
  std::string DebugString() const;

// See Descriptor::DebugStringWithOptions().
  std::string DebugStringWithOptions(const DebugStringOptions& options) const;

// Source Location ---------------------------------------------------

// Updates |*out_location| to the source location of the complete
  // extent of this service declaration.  Returns false and leaves
  // |*out_location| unchanged iff location information was not available.
  bool GetSourceLocation(SourceLocation* out_location) const;

private:
  typedef ServiceOptions OptionsType;

// Allows access to GetLocationPath for annotations.
  friend class io::Printer;
  friend class compiler::cpp::Formatter;

// See Descriptor::DebugString().
  void DebugString(std::string* contents,
                   const DebugStringOptions& options) const;

// Walks up the descriptor tree to generate the source location path
  // to this descriptor from the file root.
  void GetLocationPath(std::vector<int>* output) const;

const std::string* name_;
  const std::string* full_name_;
  const FileDescriptor* file_;
  const ServiceOptions* options_;
  MethodDescriptor* methods_;
  int method_count_;
  // IMPORTANT:  If you add a new field, make sure to search for all instances
  // of Allocate<ServiceDescriptor>() and AllocateArray<ServiceDescriptor>() in
  // descriptor.cc and update them to initialize the field.

// Must be constructed using DescriptorPool.
  ServiceDescriptor() {}
  friend class DescriptorBuilder;
  friend class FileDescriptor;
  friend class MethodDescriptor;
  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(ServiceDescriptor);
};

// Describes an individual service method.  To obtain a MethodDescriptor given
// a service, first get its ServiceDescriptor, then call
// ServiceDescriptor::FindMethodByName().  Use DescriptorPool to construct your
// own descriptors.
class PROTOBUF_EXPORT MethodDescriptor {
 public:
  typedef MethodDescriptorProto Proto;

// Name of this method, not including containing scope.
  const std::string& name() const;
  // The fully-qualified name of the method, scope delimited by periods.
  const std::string& full_name() const;
  // Index within the service's Descriptor.
  int index() const;

// The .proto file in which this method was defined.  Never nullptr.
  const FileDescriptor* file() const;
  // Gets the service to which this method belongs.  Never nullptr.
  const ServiceDescriptor* service() const;

// Gets the type of protocol message which this method accepts as input.
  const Descriptor* input_type() const;
  // Gets the type of protocol message which this message produces as output.
  const Descriptor* output_type() const;

// Gets whether the client streams multiple requests.
  bool client_streaming() const;
  // Gets whether the server streams multiple responses.
  bool server_streaming() const;

// Get options for this method.  These are specified in the .proto file by
  // placing lines like "option foo = 1234;" in curly-braces after a method
  // declaration.  Allowed options are defined by MethodOptions in
  // descriptor.proto, and any available extensions of that message.
  const MethodOptions& options() const;

// See Descriptor::CopyTo().
  void CopyTo(MethodDescriptorProto* proto) const;

// See Descriptor::DebugString().
  std::string DebugString() const;

// See Descriptor::DebugStringWithOptions().
  std::string DebugStringWithOptions(const DebugStringOptions& options) const;

// Source Location ---------------------------------------------------

// Updates |*out_location| to the source location of the complete
  // extent of this method declaration.  Returns false and leaves
  // |*out_location| unchanged iff location information was not available.
  bool GetSourceLocation(SourceLocation* out_location) const;

private:
  typedef MethodOptions OptionsType;

// Allows access to GetLocationPath for annotations.
  friend class io::Printer;
  friend class compiler::cpp::Formatter;

// See Descriptor::DebugString().
  void DebugString(int depth, std::string* contents,
                   const DebugStringOptions& options) const;

// Walks up the descriptor tree to generate the source location path
  // to this descriptor from the file root.
  void GetLocationPath(std::vector<int>* output) const;

const std::string* name_;
  const std::string* full_name_;
  const ServiceDescriptor* service_;
  mutable internal::LazyDescriptor input_type_;
  mutable internal::LazyDescriptor output_type_;
  const MethodOptions* options_;
  bool client_streaming_;
  bool server_streaming_;
  // IMPORTANT:  If you add a new field, make sure to search for all instances
  // of Allocate<MethodDescriptor>() and AllocateArray<MethodDescriptor>() in
  // descriptor.cc and update them to initialize the field.

// Must be constructed using DescriptorPool.
  MethodDescriptor() {}
  friend class DescriptorBuilder;
  friend class ServiceDescriptor;
  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(MethodDescriptor);
};

// Describes a whole .proto file.  To get the FileDescriptor for a compiled-in
// file, get the descriptor for something defined in that file and call
// descriptor->file().  Use DescriptorPool to construct your own descriptors.
class PROTOBUF_EXPORT FileDescriptor {
 public:
  typedef FileDescriptorProto Proto;

// The filename, relative to the source tree.
  // e.g. "foo/bar/baz.proto"
  const std::string& name() const;

// The package, e.g. "google.protobuf.compiler".
  const std::string& package() const;

// The DescriptorPool in which this FileDescriptor and all its contents were
  // allocated.  Never nullptr.
  const DescriptorPool* pool() const;

// The number of files imported by this one.
  int dependency_count() const;
  // Gets an imported file by index, where 0 <= index < dependency_count().
  // These are returned in the order they were defined in the .proto file.
  const FileDescriptor* dependency(int index) const;

// The number of files public imported by this one.
  // The public dependency list is a subset of the dependency list.
  int public_dependency_count() const;
  // Gets a public imported file by index, where 0 <= index <
  // public_dependency_count().
  // These are returned in the order they were defined in the .proto file.
  const FileDescriptor* public_dependency(int index) const;

// The number of files that are imported for weak fields.
  // The weak dependency list is a subset of the dependency list.
  int weak_dependency_count() const;
  // Gets a weak imported file by index, where 0 <= index <
  // weak_dependency_count().
  // These are returned in the order they were defined in the .proto file.
  const FileDescriptor* weak_dependency(int index) const;

// Number of top-level message types defined in this file.  (This does not
  // include nested types.)
  int message_type_count() const;
  // Gets a top-level message type, where 0 <= index < message_type_count().
  // These are returned in the order they were defined in the .proto file.
  const Descriptor* message_type(int index) const;

// Number of top-level enum types defined in this file.  (This does not
  // include nested types.)
  int enum_type_count() const;
  // Gets a top-level enum type, where 0 <= index < enum_type_count().
  // These are returned in the order they were defined in the .proto file.
  const EnumDescriptor* enum_type(int index) const;

// Number of services defined in this file.
  int service_count() const;
  // Gets a service, where 0 <= index < service_count().
  // These are returned in the order they were defined in the .proto file.
  const ServiceDescriptor* service(int index) const;

// Number of extensions defined at file scope.  (This does not include
  // extensions nested within message types.)
  int extension_count() const;
  // Gets an extension's descriptor, where 0 <= index < extension_count().
  // These are returned in the order they were defined in the .proto file.
  const FieldDescriptor* extension(int index) const;

// Get options for this file.  These are specified in the .proto file by
  // placing lines like "option foo = 1234;" at the top level, outside of any
  // other definitions.  Allowed options are defined by FileOptions in
  // descriptor.proto, and any available extensions of that message.
  const FileOptions& options() const;

// Syntax of this file.
  enum Syntax {
    SYNTAX_UNKNOWN = 0,
    SYNTAX_PROTO2 = 2,
    SYNTAX_PROTO3 = 3,
  };
  Syntax syntax() const;
  static const char* SyntaxName(Syntax syntax);

// Find a top-level message type by name.  Returns nullptr if not found.
  const Descriptor* FindMessageTypeByName(const std::string& name) const;
  // Find a top-level enum type by name.  Returns nullptr if not found.
  const EnumDescriptor* FindEnumTypeByName(const std::string& name) const;
  // Find an enum value defined in any top-level enum by name.  Returns nullptr
  // if not found.
  const EnumValueDescriptor* FindEnumValueByName(const std::string& name) const;
  // Find a service definition by name.  Returns nullptr if not found.
  const ServiceDescriptor* FindServiceByName(const std::string& name) const;
  // Find a top-level extension definition by name.  Returns nullptr if not
  // found.
  const FieldDescriptor* FindExtensionByName(const std::string& name) const;
  // Similar to FindExtensionByName(), but searches by lowercased-name.  See
  // Descriptor::FindFieldByLowercaseName().
  const FieldDescriptor* FindExtensionByLowercaseName(
      const std::string& name) const;
  // Similar to FindExtensionByName(), but searches by camelcased-name.  See
  // Descriptor::FindFieldByCamelcaseName().
  const FieldDescriptor* FindExtensionByCamelcaseName(
      const std::string& name) const;

// See Descriptor::CopyTo().
  // Notes:
  // - This method does NOT copy source code information since it is relatively
  //   large and rarely needed.  See CopySourceCodeInfoTo() below.
  void CopyTo(FileDescriptorProto* proto) const;
  // Write the source code information of this FileDescriptor into the given
  // FileDescriptorProto.  See CopyTo() above.
  void CopySourceCodeInfoTo(FileDescriptorProto* proto) const;
  // Fill the json_name field of FieldDescriptorProto for all fields. Can only
  // be called after CopyTo().
  void CopyJsonNameTo(FileDescriptorProto* proto) const;

// See Descriptor::DebugString().
  std::string DebugString() const;

// See Descriptor::DebugStringWithOptions().
  std::string DebugStringWithOptions(const DebugStringOptions& options) const;

// Returns true if this is a placeholder for an unknown file. This will
  // only be the case if this descriptor comes from a DescriptorPool
  // with AllowUnknownDependencies() set.
  bool is_placeholder() const;

// Updates |*out_location| to the source location of the complete extent of
  // this file declaration (namely, the empty path).
  bool GetSourceLocation(SourceLocation* out_location) const;

// Updates |*out_location| to the source location of the complete
  // extent of the declaration or declaration-part denoted by |path|.
  // Returns false and leaves |*out_location| unchanged iff location
  // information was not available.  (See SourceCodeInfo for
  // description of path encoding.)
  bool GetSourceLocation(const std::vector<int>& path,
                         SourceLocation* out_location) const;

private:
  typedef FileOptions OptionsType;

const std::string* name_;
  const std::string* package_;
  const DescriptorPool* pool_;
  internal::once_flag* dependencies_once_;
  static void DependenciesOnceInit(const FileDescriptor* to_init);
  void InternalDependenciesOnceInit() const;

// These are arranged to minimize padding on 64-bit.
  int dependency_count_;
  int public_dependency_count_;
  int weak_dependency_count_;
  int message_type_count_;
  int enum_type_count_;
  int service_count_;
  int extension_count_;
  Syntax syntax_;
  bool is_placeholder_;

// Indicates the FileDescriptor is completed building. Used to verify
  // that type accessor functions that can possibly build a dependent file
  // aren't called during the process of building the file.
  bool finished_building_;

mutable const FileDescriptor** dependencies_;
  const std::string** dependencies_names_;
  int* public_dependencies_;
  int* weak_dependencies_;
  Descriptor* message_types_;
  EnumDescriptor* enum_types_;
  ServiceDescriptor* services_;
  FieldDescriptor* extensions_;
  const FileOptions* options_;

const FileDescriptorTables* tables_;
  const SourceCodeInfo* source_code_info_;

// IMPORTANT:  If you add a new field, make sure to search for all instances
  // of Allocate<FileDescriptor>() and AllocateArray<FileDescriptor>() in
  // descriptor.cc and update them to initialize the field.

FileDescriptor() {}
  friend class DescriptorBuilder;
  friend class DescriptorPool;
  friend class Descriptor;
  friend class FieldDescriptor;
  friend class internal::LazyDescriptor;
  friend class OneofDescriptor;
  friend class EnumDescriptor;
  friend class EnumValueDescriptor;
  friend class MethodDescriptor;
  friend class ServiceDescriptor;
  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(FileDescriptor);
};

// ===================================================================

// Used to construct descriptors.
//
// Normally you won't want to build your own descriptors.  Message classes
// constructed by the protocol compiler will provide them for you.  However,
// if you are implementing Message on your own, or if you are writing a
// program which can operate on totally arbitrary types and needs to load
// them from some sort of database, you might need to.
//
// Since Descriptors are composed of a whole lot of cross-linked bits of
// data that would be a pain to put together manually, the
// DescriptorPool class is provided to make the process easier.  It can
// take a FileDescriptorProto (defined in descriptor.proto), validate it,
// and convert it to a set of nicely cross-linked Descriptors.
//
// DescriptorPool also helps with memory management.  Descriptors are
// composed of many objects containing static data and pointers to each
// other.  In all likelihood, when it comes time to delete this data,
// you'll want to delete it all at once.  In fact, it is not uncommon to
// have a whole pool of descriptors all cross-linked with each other which
// you wish to delete all at once.  This class represents such a pool, and
// handles the memory management for you.
//
// You can also search for descriptors within a DescriptorPool by name, and
// extensions by number.
class PROTOBUF_EXPORT DescriptorPool {
 public:
  // Create a normal, empty DescriptorPool.
  DescriptorPool();

// Constructs a DescriptorPool that, when it can't find something among the
  // descriptors already in the pool, looks for it in the given
  // DescriptorDatabase.
  // Notes:
  // - If a DescriptorPool is constructed this way, its BuildFile*() methods
  //   must not be called (they will assert-fail).  The only way to populate
  //   the pool with descriptors is to call the Find*By*() methods.
  // - The Find*By*() methods may block the calling thread if the
  //   DescriptorDatabase blocks.  This in turn means that parsing messages
  //   may block if they need to look up extensions.
  // - The Find*By*() methods will use mutexes for thread-safety, thus making
  //   them slower even when they don't have to fall back to the database.
  //   In fact, even the Find*By*() methods of descriptor objects owned by
  //   this pool will be slower, since they will have to obtain locks too.
  // - An ErrorCollector may optionally be given to collect validation errors
  //   in files loaded from the database.  If not given, errors will be printed
  //   to GOOGLE_LOG(ERROR).  Remember that files are built on-demand, so this
  //   ErrorCollector may be called from any thread that calls one of the
  //   Find*By*() methods.
  // - The DescriptorDatabase must not be mutated during the lifetime of
  //   the DescriptorPool. Even if the client takes care to avoid data races,
  //   changes to the content of the DescriptorDatabase may not be reflected
  //   in subsequent lookups in the DescriptorPool.
  class ErrorCollector;
  explicit DescriptorPool(DescriptorDatabase* fallback_database,
                          ErrorCollector* error_collector = nullptr);

~DescriptorPool();

// Get a pointer to the generated pool.  Generated protocol message classes
  // which are compiled into the binary will allocate their descriptors in
  // this pool.  Do not add your own descriptors to this pool.
  static const DescriptorPool* generated_pool();

// Find a FileDescriptor in the pool by file name.  Returns nullptr if not
  // found.
  const FileDescriptor* FindFileByName(const std::string& name) const;

// Find the FileDescriptor in the pool which defines the given symbol.
  // If any of the Find*ByName() methods below would succeed, then this is
  // equivalent to calling that method and calling the result's file() method.
  // Otherwise this returns nullptr.
  const FileDescriptor* FindFileContainingSymbol(
      const std::string& symbol_name) const;

// Looking up descriptors ------------------------------------------
  // These find descriptors by fully-qualified name.  These will find both
  // top-level descriptors and nested descriptors.  They return nullptr if not
  // found.

const Descriptor* FindMessageTypeByName(const std::string& name) const;
  const FieldDescriptor* FindFieldByName(const std::string& name) const;
  const FieldDescriptor* FindExtensionByName(const std::string& name) const;
  const OneofDescriptor* FindOneofByName(const std::string& name) const;
  const EnumDescriptor* FindEnumTypeByName(const std::string& name) const;
  const EnumValueDescriptor* FindEnumValueByName(const std::string& name) const;
  const ServiceDescriptor* FindServiceByName(const std::string& name) const;
  const MethodDescriptor* FindMethodByName(const std::string& name) const;

// Finds an extension of the given type by number.  The extendee must be
  // a member of this DescriptorPool or one of its underlays.
  const FieldDescriptor* FindExtensionByNumber(const Descriptor* extendee,
                                               int number) const;

// Finds an extension of the given type by its printable name.
  // See comments above PrintableNameForExtension() for the definition of
  // "printable name".  The extendee must be a member of this DescriptorPool
  // or one of its underlays.  Returns nullptr if there is no known message
  // extension with the given printable name.
  const FieldDescriptor* FindExtensionByPrintableName(
      const Descriptor* extendee, const std::string& printable_name) const;

// Finds extensions of extendee. The extensions will be appended to
  // out in an undefined order. Only extensions defined directly in
  // this DescriptorPool or one of its underlays are guaranteed to be
  // found: extensions defined in the fallback database might not be found
  // depending on the database implementation.
  void FindAllExtensions(const Descriptor* extendee,
                         std::vector<const FieldDescriptor*>* out) const;

// Building descriptors --------------------------------------------

// When converting a FileDescriptorProto to a FileDescriptor, various
  // errors might be detected in the input.  The caller may handle these
  // programmatically by implementing an ErrorCollector.
  class PROTOBUF_EXPORT ErrorCollector {
   public:
    inline ErrorCollector() {}
    virtual ~ErrorCollector();

// These constants specify what exact part of the construct is broken.
    // This is useful e.g. for mapping the error back to an exact location
    // in a .proto file.
    enum ErrorLocation {
      NAME,           // the symbol name, or the package name for files
      NUMBER,         // field or extension range number
      TYPE,           // field type
      EXTENDEE,       // field extendee
      DEFAULT_VALUE,  // field default value
      INPUT_TYPE,     // method input type
      OUTPUT_TYPE,    // method output type
      OPTION_NAME,    // name in assignment
      OPTION_VALUE,   // value in option assignment
      IMPORT,         // import error
      OTHER           // some other problem
    };

// Reports an error in the FileDescriptorProto. Use this function if the
    // problem occurred should interrupt building the FileDescriptorProto.
    virtual void AddError(
        const std::string& filename,  // File name in which the error occurred.
        const std::string& element_name,  // Full name of the erroneous element.
        const Message* descriptor,  // Descriptor of the erroneous element.
        ErrorLocation location,     // One of the location constants, above.
        const std::string& message  // Human-readable error message.
        ) = 0;

// Reports a warning in the FileDescriptorProto. Use this function if the
    // problem occurred should NOT interrupt building the FileDescriptorProto.
    virtual void AddWarning(
        const std::string& /*filename*/,      // File name in which the error
                                              // occurred.
        const std::string& /*element_name*/,  // Full name of the erroneous
                                              // element.
        const Message* /*descriptor*/,  // Descriptor of the erroneous element.
        ErrorLocation /*location*/,     // One of the location constants, above.
        const std::string& /*message*/  // Human-readable error message.
    ) {}

private:
    GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(ErrorCollector);
  };

// Convert the FileDescriptorProto to real descriptors and place them in
  // this DescriptorPool.  All dependencies of the file must already be in
  // the pool.  Returns the resulting FileDescriptor, or nullptr if there were
  // problems with the input (e.g. the message was invalid, or dependencies
  // were missing).  Details about the errors are written to GOOGLE_LOG(ERROR).
  const FileDescriptor* BuildFile(const FileDescriptorProto& proto);

// Same as BuildFile() except errors are sent to the given ErrorCollector.
  const FileDescriptor* BuildFileCollectingErrors(
      const FileDescriptorProto& proto, ErrorCollector* error_collector);

// By default, it is an error if a FileDescriptorProto contains references
  // to types or other files that are not found in the DescriptorPool (or its
  // backing DescriptorDatabase, if any).  If you call
  // AllowUnknownDependencies(), however, then unknown types and files
  // will be replaced by placeholder descriptors (which can be identified by
  // the is_placeholder() method).  This can allow you to
  // perform some useful operations with a .proto file even if you do not
  // have access to other .proto files on which it depends.  However, some
  // heuristics must be used to fill in the gaps in information, and these
  // can lead to descriptors which are inaccurate.  For example, the
  // DescriptorPool may be forced to guess whether an unknown type is a message
  // or an enum, as well as what package it resides in.  Furthermore,
  // placeholder types will not be discoverable via FindMessageTypeByName()
  // and similar methods, which could confuse some descriptor-based algorithms.
  // Generally, the results of this option should be handled with extreme care.
  void AllowUnknownDependencies() { allow_unknown_ = true; }

// By default, weak imports are allowed to be missing, in which case we will
  // use a placeholder for the dependency and convert the field to be an Empty
  // message field. If you call EnforceWeakDependencies(true), however, the
  // DescriptorPool will report a import not found error.
  void EnforceWeakDependencies(bool enforce) { enforce_weak_ = enforce; }

// Internal stuff --------------------------------------------------
  // These methods MUST NOT be called from outside the proto2 library.
  // These methods may contain hidden pitfalls and may be removed in a
  // future library version.

// Create a DescriptorPool which is overlaid on top of some other pool.
  // If you search for a descriptor in the overlay and it is not found, the
  // underlay will be searched as a backup.  If the underlay has its own
  // underlay, that will be searched next, and so on.  This also means that
  // files built in the overlay will be cross-linked with the underlay's
  // descriptors if necessary.  The underlay remains property of the caller;
  // it must remain valid for the lifetime of the newly-constructed pool.
  //
  // Example:  Say you want to parse a .proto file at runtime in order to use
  // its type with a DynamicMessage.  Say this .proto file has dependencies,
  // but you know that all the dependencies will be things that are already
  // compiled into the binary.  For ease of use, you'd like to load the types
  // right out of generated_pool() rather than have to parse redundant copies
  // of all these .protos and runtime.  But, you don't want to add the parsed
  // types directly into generated_pool(): this is not allowed, and would be
  // bad design anyway.  So, instead, you could use generated_pool() as an
  // underlay for a new DescriptorPool in which you add only the new file.
  //
  // WARNING:  Use of underlays can lead to many subtle gotchas.  Instead,
  //   try to formulate what you want to do in terms of DescriptorDatabases.
  explicit DescriptorPool(const DescriptorPool* underlay);

// Called by generated classes at init time to add their descriptors to
  // generated_pool.  Do NOT call this in your own code!  filename must be a
  // permanent string (e.g. a string literal).
  static void InternalAddGeneratedFile(const void* encoded_file_descriptor,
                                       int size);

// Disallow [enforce_utf8 = false] in .proto files.
  void DisallowEnforceUtf8() { disallow_enforce_utf8_ = true; }

// For internal use only:  Gets a non-const pointer to the generated pool.
  // This is called at static-initialization time only, so thread-safety is
  // not a concern.  If both an underlay and a fallback database are present,
  // the underlay takes precedence.
  static DescriptorPool* internal_generated_pool();

// For internal use only:  Changes the behavior of BuildFile() such that it
  // allows the file to make reference to message types declared in other files
  // which it did not officially declare as dependencies.
  void InternalDontEnforceDependencies();

// For internal use only: Enables lazy building of dependencies of a file.
  // Delay the building of dependencies of a file descriptor until absolutely
  // necessary, like when message_type() is called on a field that is defined
  // in that dependency's file. This will cause functional issues if a proto
  // or one of it's dependencies has errors. Should only be enabled for the
  // generated_pool_ (because no descriptor build errors are guaranteed by
  // the compilation generation process), testing, or if a lack of descriptor
  // build errors can be guaranteed for a pool.
  void InternalSetLazilyBuildDependencies() {
    lazily_build_dependencies_ = true;
    // This needs to be set when lazily building dependencies, as it breaks
    // dependency checking.
    InternalDontEnforceDependencies();
  }

// For internal use only.
  void internal_set_underlay(const DescriptorPool* underlay) {
    underlay_ = underlay;
  }

// For internal (unit test) use only:  Returns true if a FileDescriptor has
  // been constructed for the given file, false otherwise.  Useful for testing
  // lazy descriptor initialization behavior.
  bool InternalIsFileLoaded(const std::string& filename) const;

// Add a file to unused_import_track_files_. DescriptorBuilder will log
  // warnings or errors for those files if there is any unused import.
  void AddUnusedImportTrackFile(const std::string& file_name,
                                bool is_error = false);
  void ClearUnusedImportTrackFiles();

private:
  friend class Descriptor;
  friend class internal::LazyDescriptor;
  friend class FieldDescriptor;
  friend class EnumDescriptor;
  friend class ServiceDescriptor;
  friend class MethodDescriptor;
  friend class FileDescriptor;
  friend class StreamDescriptor;
  friend class DescriptorBuilder;
  friend class FileDescriptorTables;

// Return true if the given name is a sub-symbol of any non-package
  // descriptor that already exists in the descriptor pool.  (The full
  // definition of such types is already known.)
  bool IsSubSymbolOfBuiltType(const std::string& name) const;

// Tries to find something in the fallback database and link in the
  // corresponding proto file.  Returns true if successful, in which case
  // the caller should search for the thing again.  These are declared
  // const because they are called by (semantically) const methods.
  bool TryFindFileInFallbackDatabase(const std::string& name) const;
  bool TryFindSymbolInFallbackDatabase(const std::string& name) const;
  bool TryFindExtensionInFallbackDatabase(const Descriptor* containing_type,
                                          int field_number) const;

// This internal find extension method only check with its table and underlay
  // descriptor_pool's table. It does not check with fallback DB and no
  // additional proto file will be build in this method.
  const FieldDescriptor* InternalFindExtensionByNumberNoLock(
      const Descriptor* extendee, int number) const;

// Like BuildFile() but called internally when the file has been loaded from
  // fallback_database_.  Declared const because it is called by (semantically)
  // const methods.
  const FileDescriptor* BuildFileFromDatabase(
      const FileDescriptorProto& proto) const;

// Helper for when lazily_build_dependencies_ is set, can look up a symbol
  // after the file's descriptor is built, and can build the file where that
  // symbol is defined if necessary. Will create a placeholder if the type
  // doesn't exist in the fallback database, or the file doesn't build
  // successfully.
  Symbol CrossLinkOnDemandHelper(const std::string& name,
                                 bool expecting_enum) const;

// Create a placeholder FileDescriptor of the specified name
  FileDescriptor* NewPlaceholderFile(const std::string& name) const;
  FileDescriptor* NewPlaceholderFileWithMutexHeld(
      const std::string& name) const;

enum PlaceholderType {
    PLACEHOLDER_MESSAGE,
    PLACEHOLDER_ENUM,
    PLACEHOLDER_EXTENDABLE_MESSAGE
  };
  // Create a placeholder Descriptor of the specified name
  Symbol NewPlaceholder(const std::string& name,
                        PlaceholderType placeholder_type) const;
  Symbol NewPlaceholderWithMutexHeld(const std::string& name,
                                     PlaceholderType placeholder_type) const;

// If fallback_database_ is nullptr, this is nullptr.  Otherwise, this is a
  // mutex which must be locked while accessing tables_.
  internal::WrappedMutex* mutex_;

// See constructor.
  DescriptorDatabase* fallback_database_;
  ErrorCollector* default_error_collector_;
  const DescriptorPool* underlay_;

// This class contains a lot of hash maps with complicated types that
  // we'd like to keep out of the header.
  class Tables;
  std::unique_ptr<Tables> tables_;

bool enforce_dependencies_;
  bool lazily_build_dependencies_;
  bool allow_unknown_;
  bool enforce_weak_;
  bool disallow_enforce_utf8_;

// Set of files to track for unused imports. The bool value when true means
  // unused imports are treated as errors (and as warnings when false).
  std::map<std::string, bool> unused_import_track_files_;

GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(DescriptorPool);
};

// inline methods ====================================================

// These macros makes this repetitive code more readable.
#define PROTOBUF_DEFINE_ACCESSOR(CLASS, FIELD, TYPE) \
  inline TYPE CLASS::FIELD() const { return FIELD##_; }

// Strings fields are stored as pointers but returned as const references.
#define PROTOBUF_DEFINE_STRING_ACCESSOR(CLASS, FIELD) \
  inline const std::string& CLASS::FIELD() const { return *FIELD##_; }

// Arrays take an index parameter, obviously.
#define PROTOBUF_DEFINE_ARRAY_ACCESSOR(CLASS, FIELD, TYPE) \
  inline TYPE CLASS::FIELD(int index) const { return FIELD##s_ + index; }

#define PROTOBUF_DEFINE_OPTIONS_ACCESSOR(CLASS, TYPE) \
  inline const TYPE& CLASS::options() const { return *options_; }

PROTOBUF_DEFINE_STRING_ACCESSOR(Descriptor, name)
PROTOBUF_DEFINE_STRING_ACCESSOR(Descriptor, full_name)
PROTOBUF_DEFINE_ACCESSOR(Descriptor, file, const FileDescriptor*)
PROTOBUF_DEFINE_ACCESSOR(Descriptor, containing_type, const Descriptor*)

PROTOBUF_DEFINE_ACCESSOR(Descriptor, field_count, int)
PROTOBUF_DEFINE_ACCESSOR(Descriptor, oneof_decl_count, int)
PROTOBUF_DEFINE_ACCESSOR(Descriptor, real_oneof_decl_count, int)
PROTOBUF_DEFINE_ACCESSOR(Descriptor, nested_type_count, int)
PROTOBUF_DEFINE_ACCESSOR(Descriptor, enum_type_count, int)

PROTOBUF_DEFINE_ARRAY_ACCESSOR(Descriptor, field, const FieldDescriptor*)
PROTOBUF_DEFINE_ARRAY_ACCESSOR(Descriptor, oneof_decl, const OneofDescriptor*)
PROTOBUF_DEFINE_ARRAY_ACCESSOR(Descriptor, nested_type, const Descriptor*)
PROTOBUF_DEFINE_ARRAY_ACCESSOR(Descriptor, enum_type, const EnumDescriptor*)

PROTOBUF_DEFINE_ACCESSOR(Descriptor, extension_range_count, int)
PROTOBUF_DEFINE_ACCESSOR(Descriptor, extension_count, int)
PROTOBUF_DEFINE_ARRAY_ACCESSOR(Descriptor, extension_range,
                               const Descriptor::ExtensionRange*)
PROTOBUF_DEFINE_ARRAY_ACCESSOR(Descriptor, extension, const FieldDescriptor*)

PROTOBUF_DEFINE_ACCESSOR(Descriptor, reserved_range_count, int)
PROTOBUF_DEFINE_ARRAY_ACCESSOR(Descriptor, reserved_range,
                               const Descriptor::ReservedRange*)
PROTOBUF_DEFINE_ACCESSOR(Descriptor, reserved_name_count, int)

PROTOBUF_DEFINE_OPTIONS_ACCESSOR(Descriptor, MessageOptions)
PROTOBUF_DEFINE_ACCESSOR(Descriptor, is_placeholder, bool)

PROTOBUF_DEFINE_STRING_ACCESSOR(FieldDescriptor, name)
PROTOBUF_DEFINE_STRING_ACCESSOR(FieldDescriptor, full_name)
PROTOBUF_DEFINE_STRING_ACCESSOR(FieldDescriptor, json_name)
PROTOBUF_DEFINE_STRING_ACCESSOR(FieldDescriptor, lowercase_name)
PROTOBUF_DEFINE_STRING_ACCESSOR(FieldDescriptor, camelcase_name)
PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, file, const FileDescriptor*)
PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, number, int)
PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, is_extension, bool)
PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, label, FieldDescriptor::Label)
PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, containing_type, const Descriptor*)
PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, containing_oneof,
                         const OneofDescriptor*)
PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, index_in_oneof, int)
PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, extension_scope, const Descriptor*)
PROTOBUF_DEFINE_OPTIONS_ACCESSOR(FieldDescriptor, FieldOptions)
PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, has_default_value, bool)
PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, has_json_name, bool)
PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, default_value_int32, int32)
PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, default_value_int64, int64)
PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, default_value_uint32, uint32)
PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, default_value_uint64, uint64)
PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, default_value_float, float)
PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, default_value_double, double)
PROTOBUF_DEFINE_ACCESSOR(FieldDescriptor, default_value_bool, bool)
PROTOBUF_DEFINE_STRING_ACCESSOR(FieldDescriptor, default_value_string)

PROTOBUF_DEFINE_STRING_ACCESSOR(OneofDescriptor, name)
PROTOBUF_DEFINE_STRING_ACCESSOR(OneofDescriptor, full_name)
PROTOBUF_DEFINE_ACCESSOR(OneofDescriptor, containing_type, const Descriptor*)
PROTOBUF_DEFINE_ACCESSOR(OneofDescriptor, field_count, int)
PROTOBUF_DEFINE_OPTIONS_ACCESSOR(OneofDescriptor, OneofOptions)

PROTOBUF_DEFINE_STRING_ACCESSOR(EnumDescriptor, name)
PROTOBUF_DEFINE_STRING_ACCESSOR(EnumDescriptor, full_name)
PROTOBUF_DEFINE_ACCESSOR(EnumDescriptor, file, const FileDescriptor*)
PROTOBUF_DEFINE_ACCESSOR(EnumDescriptor, containing_type, const Descriptor*)
PROTOBUF_DEFINE_ACCESSOR(EnumDescriptor, value_count, int)
PROTOBUF_DEFINE_ARRAY_ACCESSOR(EnumDescriptor, value,
                               const EnumValueDescriptor*)
PROTOBUF_DEFINE_OPTIONS_ACCESSOR(EnumDescriptor, EnumOptions)
PROTOBUF_DEFINE_ACCESSOR(EnumDescriptor, is_placeholder, bool)
PROTOBUF_DEFINE_ACCESSOR(EnumDescriptor, reserved_range_count, int)
PROTOBUF_DEFINE_ARRAY_ACCESSOR(EnumDescriptor, reserved_range,
                               const EnumDescriptor::ReservedRange*)
PROTOBUF_DEFINE_ACCESSOR(EnumDescriptor, reserved_name_count, int)

PROTOBUF_DEFINE_STRING_ACCESSOR(EnumValueDescriptor, name)
PROTOBUF_DEFINE_STRING_ACCESSOR(EnumValueDescriptor, full_name)
PROTOBUF_DEFINE_ACCESSOR(EnumValueDescriptor, number, int)
PROTOBUF_DEFINE_ACCESSOR(EnumValueDescriptor, type, const EnumDescriptor*)
PROTOBUF_DEFINE_OPTIONS_ACCESSOR(EnumValueDescriptor, EnumValueOptions)

PROTOBUF_DEFINE_STRING_ACCESSOR(ServiceDescriptor, name)
PROTOBUF_DEFINE_STRING_ACCESSOR(ServiceDescriptor, full_name)
PROTOBUF_DEFINE_ACCESSOR(ServiceDescriptor, file, const FileDescriptor*)
PROTOBUF_DEFINE_ACCESSOR(ServiceDescriptor, method_count, int)
PROTOBUF_DEFINE_ARRAY_ACCESSOR(ServiceDescriptor, method,
                               const MethodDescriptor*)
PROTOBUF_DEFINE_OPTIONS_ACCESSOR(ServiceDescriptor, ServiceOptions)

PROTOBUF_DEFINE_STRING_ACCESSOR(MethodDescriptor, name)
PROTOBUF_DEFINE_STRING_ACCESSOR(MethodDescriptor, full_name)
PROTOBUF_DEFINE_ACCESSOR(MethodDescriptor, service, const ServiceDescriptor*)
PROTOBUF_DEFINE_OPTIONS_ACCESSOR(MethodDescriptor, MethodOptions)
PROTOBUF_DEFINE_ACCESSOR(MethodDescriptor, client_streaming, bool)
PROTOBUF_DEFINE_ACCESSOR(MethodDescriptor, server_streaming, bool)

PROTOBUF_DEFINE_STRING_ACCESSOR(FileDescriptor, name)
PROTOBUF_DEFINE_STRING_ACCESSOR(FileDescriptor, package)
PROTOBUF_DEFINE_ACCESSOR(FileDescriptor, pool, const DescriptorPool*)
PROTOBUF_DEFINE_ACCESSOR(FileDescriptor, dependency_count, int)
PROTOBUF_DEFINE_ACCESSOR(FileDescriptor, public_dependency_count, int)
PROTOBUF_DEFINE_ACCESSOR(FileDescriptor, weak_dependency_count, int)
PROTOBUF_DEFINE_ACCESSOR(FileDescriptor, message_type_count, int)
PROTOBUF_DEFINE_ACCESSOR(FileDescriptor, enum_type_count, int)
PROTOBUF_DEFINE_ACCESSOR(FileDescriptor, service_count, int)
PROTOBUF_DEFINE_ACCESSOR(FileDescriptor, extension_count, int)
PROTOBUF_DEFINE_OPTIONS_ACCESSOR(FileDescriptor, FileOptions)
PROTOBUF_DEFINE_ACCESSOR(FileDescriptor, is_placeholder, bool)

PROTOBUF_DEFINE_ARRAY_ACCESSOR(FileDescriptor, message_type, const Descriptor*)
PROTOBUF_DEFINE_ARRAY_ACCESSOR(FileDescriptor, enum_type, const EnumDescriptor*)
PROTOBUF_DEFINE_ARRAY_ACCESSOR(FileDescriptor, service,
                               const ServiceDescriptor*)
PROTOBUF_DEFINE_ARRAY_ACCESSOR(FileDescriptor, extension,
                               const FieldDescriptor*)

#undef PROTOBUF_DEFINE_ACCESSOR
#undef PROTOBUF_DEFINE_STRING_ACCESSOR
#undef PROTOBUF_DEFINE_ARRAY_ACCESSOR

// A few accessors differ from the macros...

inline Descriptor::WellKnownType Descriptor::well_known_type() const {
  return static_cast<Descriptor::WellKnownType>(well_known_type_);
}

inline bool Descriptor::IsExtensionNumber(int number) const {
  return FindExtensionRangeContainingNumber(number) != nullptr;
}

inline bool Descriptor::IsReservedNumber(int number) const {
  return FindReservedRangeContainingNumber(number) != nullptr;
}

inline bool Descriptor::IsReservedName(const std::string& name) const {
  for (int i = 0; i < reserved_name_count(); i++) {
    if (name == reserved_name(i)) {
      return true;
    }
  }
  return false;
}

// Can't use PROTOBUF_DEFINE_ARRAY_ACCESSOR because reserved_names_ is actually
// an array of pointers rather than the usual array of objects.
inline const std::string& Descriptor::reserved_name(int index) const {
  return *reserved_names_[index];
}

inline bool EnumDescriptor::IsReservedNumber(int number) const {
  return FindReservedRangeContainingNumber(number) != nullptr;
}

inline bool EnumDescriptor::IsReservedName(const std::string& name) const {
  for (int i = 0; i < reserved_name_count(); i++) {
    if (name == reserved_name(i)) {
      return true;
    }
  }
  return false;
}

// Can't use PROTOBUF_DEFINE_ARRAY_ACCESSOR because reserved_names_ is actually
// an array of pointers rather than the usual array of objects.
inline const std::string& EnumDescriptor::reserved_name(int index) const {
  return *reserved_names_[index];
}

inline FieldDescriptor::Type FieldDescriptor::type() const {
  if (type_once_) {
    internal::call_once(*type_once_, &FieldDescriptor::TypeOnceInit, this);
  }
  return type_;
}

inline bool FieldDescriptor::is_required() const {
  return label() == LABEL_REQUIRED;
}

inline bool FieldDescriptor::is_optional() const {
  return label() == LABEL_OPTIONAL;
}

inline bool FieldDescriptor::is_repeated() const {
  return label() == LABEL_REPEATED;
}

inline bool FieldDescriptor::is_packable() const {
  return is_repeated() && IsTypePackable(type());
}

inline bool FieldDescriptor::is_map() const {
  return type() == TYPE_MESSAGE && is_map_message_type();
}

inline bool FieldDescriptor::has_optional_keyword() const {
  return proto3_optional_ ||
         (file()->syntax() == FileDescriptor::SYNTAX_PROTO2 && is_optional() &&
          !containing_oneof());
}

inline const OneofDescriptor* FieldDescriptor::real_containing_oneof() const {
  return containing_oneof_ && !containing_oneof_->is_synthetic()
             ? containing_oneof_
             : nullptr;
}

inline bool FieldDescriptor::has_presence() const {
  if (is_repeated()) return false;
  return cpp_type() == CPPTYPE_MESSAGE || containing_oneof() ||
         file()->syntax() == FileDescriptor::SYNTAX_PROTO2;
}

// To save space, index() is computed by looking at the descriptor's position
// in the parent's array of children.
inline int FieldDescriptor::index() const {
  if (!is_extension_) {
    return static_cast<int>(this - containing_type()->fields_);
  } else if (extension_scope_ != nullptr) {
    return static_cast<int>(this - extension_scope_->extensions_);
  } else {
    return static_cast<int>(this - file_->extensions_);
  }
}

inline int Descriptor::index() const {
  if (containing_type_ == nullptr) {
    return static_cast<int>(this - file_->message_types_);
  } else {
    return static_cast<int>(this - containing_type_->nested_types_);
  }
}

inline const FileDescriptor* OneofDescriptor::file() const {
  return containing_type()->file();
}

inline int OneofDescriptor::index() const {
  return static_cast<int>(this - containing_type_->oneof_decls_);
}

inline bool OneofDescriptor::is_synthetic() const {
  return field_count() == 1 && field(0)->proto3_optional_;
}

inline int EnumDescriptor::index() const {
  if (containing_type_ == nullptr) {
    return static_cast<int>(this - file_->enum_types_);
  } else {
    return static_cast<int>(this - containing_type_->enum_types_);
  }
}

inline const FileDescriptor* EnumValueDescriptor::file() const {
  return type()->file();
}

inline int EnumValueDescriptor::index() const {
  return static_cast<int>(this - type_->values_);
}

inline int ServiceDescriptor::index() const {
  return static_cast<int>(this - file_->services_);
}

inline const FileDescriptor* MethodDescriptor::file() const {
  return service()->file();
}

inline int MethodDescriptor::index() const {
  return static_cast<int>(this - service_->methods_);
}

inline const char* FieldDescriptor::type_name() const {
  return kTypeToName[type()];
}

inline FieldDescriptor::CppType FieldDescriptor::cpp_type() const {
  return kTypeToCppTypeMap[type()];
}

inline const char* FieldDescriptor::cpp_type_name() const {
  return kCppTypeToName[kTypeToCppTypeMap[type()]];
}

inline FieldDescriptor::CppType FieldDescriptor::TypeToCppType(Type type) {
  return kTypeToCppTypeMap[type];
}

inline const char* FieldDescriptor::TypeName(Type type) {
  return kTypeToName[type];
}

inline const char* FieldDescriptor::CppTypeName(CppType cpp_type) {
  return kCppTypeToName[cpp_type];
}

inline bool FieldDescriptor::IsTypePackable(Type field_type) {
  return (field_type != FieldDescriptor::TYPE_STRING &&
          field_type != FieldDescriptor::TYPE_GROUP &&
          field_type != FieldDescriptor::TYPE_MESSAGE &&
          field_type != FieldDescriptor::TYPE_BYTES);
}

inline const FileDescriptor* FileDescriptor::public_dependency(
    int index) const {
  return dependency(public_dependencies_[index]);
}

inline const FileDescriptor* FileDescriptor::weak_dependency(int index) const {
  return dependency(weak_dependencies_[index]);
}

inline FileDescriptor::Syntax FileDescriptor::syntax() const { return syntax_; }

// Can't use PROTOBUF_DEFINE_ARRAY_ACCESSOR because fields_ is actually an array
// of pointers rather than the usual array of objects.
inline const FieldDescriptor* OneofDescriptor::field(int index) const {
  return fields_[index];
}

}  // namespace protobuf
}  // namespace google

#include <google/protobuf/port_undef.inc>

#endif  // GOOGLE_PROTOBUF_DESCRIPTOR_H__

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