cpp_message.h

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// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc.  All rights reserved.
// https://developers.google.com/protocol-buffers/
//
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//
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// 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
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// Author: kenton@google.com (Kenton Varda)
//  Based on original Protocol Buffers design by
//  Sanjay Ghemawat, Jeff Dean, and others.

#ifndef GOOGLE_PROTOBUF_COMPILER_CPP_MESSAGE_H__
#define GOOGLE_PROTOBUF_COMPILER_CPP_MESSAGE_H__

#include <memory>
#ifndef _SHARED_PTR_H
#include <google/protobuf/stubs/shared_ptr.h>
#endif
#include <set>
#include <string>
#include <google/protobuf/compiler/cpp/cpp_field.h>
#include <google/protobuf/compiler/cpp/cpp_options.h>

namespace google {
namespace protobuf {
  namespace io {
    class Printer;             // printer.h
  }
}

namespace protobuf {
namespace compiler {
namespace cpp {

class EnumGenerator;           // enum.h
class ExtensionGenerator;      // extension.h

class MessageGenerator {
 public:
  // See generator.cc for the meaning of dllexport_decl.
  MessageGenerator(const Descriptor* descriptor, const Options& options);
  ~MessageGenerator();

  // Header stuff.

  // Return names for foward declarations of this class and all its nested
  // types. A given key in {class,enum}_names will map from a class name to the
  // descriptor that was responsible for its inclusion in the map. This can be
  // used to associate the descriptor with the code generated for it.
  void FillMessageForwardDeclarations(
      map<string, const Descriptor*>* class_names);
  void FillEnumForwardDeclarations(
      map<string, const EnumDescriptor*>* enum_names);

  // Generate definitions of all nested enums (must come before class
  // definitions because those classes use the enums definitions).
  void GenerateEnumDefinitions(io::Printer* printer);

  // Generate specializations of GetEnumDescriptor<MyEnum>().
  // Precondition: in ::google::protobuf namespace.
  void GenerateGetEnumDescriptorSpecializations(io::Printer* printer);

  // Generate definitions for this class and all its nested types.
  void GenerateClassDefinition(io::Printer* printer);

  // Generate definitions of inline methods (placed at the end of the header
  // file).
  void GenerateInlineMethods(io::Printer* printer, bool is_inline);

  // Dependent methods are always inline.
  void GenerateDependentInlineMethods(io::Printer* printer);

  // Source file stuff.

  // Generate code which declares all the global descriptor pointers which
  // will be initialized by the methods below.
  void GenerateDescriptorDeclarations(io::Printer* printer);

  // Generate code that initializes the global variable storing the message's
  // descriptor.
  void GenerateDescriptorInitializer(io::Printer* printer, int index);

  // Generate code that calls MessageFactory::InternalRegisterGeneratedMessage()
  // for all types.
  void GenerateTypeRegistrations(io::Printer* printer);

  // Generates code that allocates the message's default instance.
  void GenerateDefaultInstanceAllocator(io::Printer* printer);

  // Generates code that initializes the message's default instance.  This
  // is separate from allocating because all default instances must be
  // allocated before any can be initialized.
  void GenerateDefaultInstanceInitializer(io::Printer* printer);

  // Generates code that should be run when ShutdownProtobufLibrary() is called,
  // to delete all dynamically-allocated objects.
  void GenerateShutdownCode(io::Printer* printer);

  // Generate all non-inline methods for this class.
  void GenerateClassMethods(io::Printer* printer);

 private:
  // Generate declarations and definitions of accessors for fields.
  void GenerateDependentBaseClassDefinition(io::Printer* printer);
  void GenerateDependentFieldAccessorDeclarations(io::Printer* printer);
  void GenerateFieldAccessorDeclarations(io::Printer* printer);
  void GenerateDependentFieldAccessorDefinitions(io::Printer* printer);
  void GenerateFieldAccessorDefinitions(io::Printer* printer, bool is_inline);

  // Generate the field offsets array.
  void GenerateOffsets(io::Printer* printer);

  // Generate constructors and destructor.
  void GenerateStructors(io::Printer* printer);

  // The compiler typically generates multiple copies of each constructor and
  // destructor: http://gcc.gnu.org/bugs.html#nonbugs_cxx
  // Placing common code in a separate method reduces the generated code size.
  //
  // Generate the shared constructor code.
  void GenerateSharedConstructorCode(io::Printer* printer);
  // Generate the shared destructor code.
  void GenerateSharedDestructorCode(io::Printer* printer);
  // Generate the arena-specific destructor code.
  void GenerateArenaDestructorCode(io::Printer* printer);

  // Generate standard Message methods.
  void GenerateClear(io::Printer* printer);
  void GenerateOneofClear(io::Printer* printer);
  void GenerateMergeFromCodedStream(io::Printer* printer);
  void GenerateSerializeWithCachedSizes(io::Printer* printer);
  void GenerateSerializeWithCachedSizesToArray(io::Printer* printer);
  void GenerateSerializeWithCachedSizesBody(io::Printer* printer,
                                            bool to_array);
  void GenerateByteSize(io::Printer* printer);
  void GenerateMergeFrom(io::Printer* printer);
  void GenerateCopyFrom(io::Printer* printer);
  void GenerateSwap(io::Printer* printer);
  void GenerateIsInitialized(io::Printer* printer);

  // Helpers for GenerateSerializeWithCachedSizes().
  void GenerateSerializeOneField(io::Printer* printer,
                                 const FieldDescriptor* field,
                                 bool unbounded);
  void GenerateSerializeOneExtensionRange(
      io::Printer* printer, const Descriptor::ExtensionRange* range,
      bool unbounded);


  // Generates has_foo() functions and variables for singular field has-bits.
  void GenerateSingularFieldHasBits(const FieldDescriptor* field,
                                    map<string, string> vars,
                                    io::Printer* printer);
  // Generates has_foo() functions and variables for oneof field has-bits.
  void GenerateOneofHasBits(io::Printer* printer, bool is_inline);
  // Generates has_foo_bar() functions for oneof members.
  void GenerateOneofMemberHasBits(const FieldDescriptor* field,
                                  const map<string, string>& vars,
                                  io::Printer* printer);
  // Generates the clear_foo() method for a field.
  void GenerateFieldClear(const FieldDescriptor* field,
                          const map<string, string>& vars,
                          io::Printer* printer);

  const Descriptor* descriptor_;
  string classname_;
  Options options_;
  FieldGeneratorMap field_generators_;
  vector< vector<string> > runs_of_fields_;  // that might be trivially cleared
  google::protobuf::scoped_array<google::protobuf::scoped_ptr<MessageGenerator> > nested_generators_;
  google::protobuf::scoped_array<google::protobuf::scoped_ptr<EnumGenerator> > enum_generators_;
  google::protobuf::scoped_array<google::protobuf::scoped_ptr<ExtensionGenerator> > extension_generators_;
  int num_required_fields_;
  bool uses_string_;
  bool use_dependent_base_;

  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(MessageGenerator);
};

}  // namespace cpp
}  // namespace compiler
}  // namespace protobuf

}  // namespace google
#endif  // GOOGLE_PROTOBUF_COMPILER_CPP_MESSAGE_H__