third_party/protobuf/src/google/protobuf/compiler/cpp/cpp

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
PrintFieldComment
SortFieldsByNumber
ShouldIgnoreRequiredFieldCheck
HasRequiredFields
HasRequiredFields
EstimateAlignmentSize
fields_
Append
SetPreferredLocation
fields
OptimizePadding
extension_generators_
GenerateForwardDeclaration
GenerateEnumDefinitions
GenerateGetEnumDescriptorSpecializations
GenerateFieldAccessorDeclarations
GenerateFieldAccessorDefinitions
GenerateClassDefinition
GenerateInlineMethods
GenerateDescriptorDeclarations
GenerateDescriptorInitializer
GenerateTypeRegistrations
GenerateDefaultInstanceAllocator
GenerateDefaultInstanceInitializer
GenerateShutdownCode
GenerateClassMethods
GenerateOffsets
GenerateSharedConstructorCode
GenerateSharedDestructorCode
GenerateStructors
GenerateClear
GenerateSwap
GenerateMergeFrom
GenerateCopyFrom
GenerateMergeFromCodedStream
GenerateSerializeOneField
GenerateSerializeOneExtensionRange
GenerateSerializeWithCachedSizes
GenerateSerializeWithCachedSizesToArray
GenerateSerializeWithCachedSizesBody
GenerateByteSize
GenerateIsInitialized
// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc.  All rights reserved.
// http://code.google.com/p/protobuf/
//
// 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.

#include <algorithm>
#include <google/protobuf/stubs/hash.h>
#include <map>
#include <utility>
#include <vector>
#include <google/protobuf/compiler/cpp/cpp_message.h>
#include <google/protobuf/compiler/cpp/cpp_field.h>
#include <google/protobuf/compiler/cpp/cpp_enum.h>
#include <google/protobuf/compiler/cpp/cpp_extension.h>
#include <google/protobuf/compiler/cpp/cpp_helpers.h>
#include <google/protobuf/stubs/strutil.h>
#include <google/protobuf/io/printer.h>
#include <google/protobuf/io/coded_stream.h>
#include <google/protobuf/wire_format.h>
#include <google/protobuf/descriptor.pb.h>


namespace google {
namespace protobuf {
namespace compiler {
namespace cpp {

using internal::WireFormat;
using internal::WireFormatLite;

namespace {

void PrintFieldComment(io::Printer* printer, const FieldDescriptor* field) {
  // Print the field's proto-syntax definition as a comment.  We don't want to
  // print group bodies so we cut off after the first line.
  string def = field->DebugString();
  printer->Print("// $def$\n",
    "def", def.substr(0, def.find_first_of('\n')));
}

struct FieldOrderingByNumber {
  inline bool operator()(const FieldDescriptor* a,
                         const FieldDescriptor* b) const {
    return a->number() < b->number();
  }
};

const char* kWireTypeNames[] = {
  "VARINT",
  "FIXED64",
  "LENGTH_DELIMITED",
  "START_GROUP",
  "END_GROUP",
  "FIXED32",
};

// Sort the fields of the given Descriptor by number into a new[]'d array
// and return it.
const FieldDescriptor** SortFieldsByNumber(const Descriptor* descriptor) {
  const FieldDescriptor** fields =
    new const FieldDescriptor*[descriptor->field_count()];
  for (int i = 0; i < descriptor->field_count(); i++) {
    fields[i] = descriptor->field(i);
  }
  sort(fields, fields + descriptor->field_count(),
       FieldOrderingByNumber());
  return fields;
}

// Functor for sorting extension ranges by their "start" field number.
struct ExtensionRangeSorter {
  bool operator()(const Descriptor::ExtensionRange* left,
                  const Descriptor::ExtensionRange* right) const {
    return left->start < right->start;
  }
};

// Returns true if the "required" restriction check should be ignored for the
// given field.
inline static bool ShouldIgnoreRequiredFieldCheck(
    const FieldDescriptor* field) {
  return false;
}

// Returns true if the message type has any required fields.  If it doesn't,
// we can optimize out calls to its IsInitialized() method.
//
// already_seen is used to avoid checking the same type multiple times
// (and also to protect against recursion).
static bool HasRequiredFields(
    const Descriptor* type,
    hash_set<const Descriptor*>* already_seen) {
  if (already_seen->count(type) > 0) {
    // Since the first occurrence of a required field causes the whole
    // function to return true, we can assume that if the type is already
    // in the cache it didn't have any required fields.
    return false;
  }
  already_seen->insert(type);

  // If the type has extensions, an extension with message type could contain
  // required fields, so we have to be conservative and assume such an
  // extension exists.
  if (type->extension_range_count() > 0) return true;

  for (int i = 0; i < type->field_count(); i++) {
    const FieldDescriptor* field = type->field(i);
    if (field->is_required()) {
      return true;
    }
    if (field->cpp_type() == FieldDescriptor::CPPTYPE_MESSAGE &&
        !ShouldIgnoreRequiredFieldCheck(field)) {
      if (HasRequiredFields(field->message_type(), already_seen)) {
        return true;
      }
    }
  }

  return false;
}

static bool HasRequiredFields(const Descriptor* type) {
  hash_set<const Descriptor*> already_seen;
  return HasRequiredFields(type, &already_seen);
}

// This returns an estimate of the compiler's alignment for the field.  This
// can't guarantee to be correct because the generated code could be compiled on
// different systems with different alignment rules.  The estimates below assume
// 64-bit pointers.
int EstimateAlignmentSize(const FieldDescriptor* field) {
  if (field == NULL) return 0;
  if (field->is_repeated()) return 8;
  switch (field->cpp_type()) {
    case FieldDescriptor::CPPTYPE_BOOL:
      return 1;

    case FieldDescriptor::CPPTYPE_INT32:
    case FieldDescriptor::CPPTYPE_UINT32:
    case FieldDescriptor::CPPTYPE_ENUM:
    case FieldDescriptor::CPPTYPE_FLOAT:
      return 4;

    case FieldDescriptor::CPPTYPE_INT64:
    case FieldDescriptor::CPPTYPE_UINT64:
    case FieldDescriptor::CPPTYPE_DOUBLE:
    case FieldDescriptor::CPPTYPE_STRING:
    case FieldDescriptor::CPPTYPE_MESSAGE:
      return 8;
  }
  GOOGLE_LOG(FATAL) << "Can't get here.";
  return -1;  // Make compiler happy.
}

// FieldGroup is just a helper for OptimizePadding below.  It holds a vector of
// fields that are grouped together because they have compatible alignment, and
// a preferred location in the final field ordering.
class FieldGroup {
 public:
  FieldGroup()
      : preferred_location_(0) {}

  // A group with a single field.
  FieldGroup(float preferred_location, const FieldDescriptor* field)
      : preferred_location_(preferred_location),
        fields_(1, field) {}

  // Append the fields in 'other' to this group.
  void Append(const FieldGroup& other) {
    if (other.fields_.empty()) {
      return;
    }
    // Preferred location is the average among all the fields, so we weight by
    // the number of fields on each FieldGroup object.
    preferred_location_ =
        (preferred_location_ * fields_.size() +
         (other.preferred_location_ * other.fields_.size())) /
        (fields_.size() + other.fields_.size());
    fields_.insert(fields_.end(), other.fields_.begin(), other.fields_.end());
  }

  void SetPreferredLocation(float location) { preferred_location_ = location; }
  const vector<const FieldDescriptor*>& fields() const { return fields_; }

  // FieldGroup objects sort by their preferred location.
  bool operator<(const FieldGroup& other) const {
    return preferred_location_ < other.preferred_location_;
  }

 private:
  // "preferred_location_" is an estimate of where this group should go in the
  // final list of fields.  We compute this by taking the average index of each
  // field in this group in the original ordering of fields.  This is very
  // approximate, but should put this group close to where its member fields
  // originally went.
  float preferred_location_;
  vector<const FieldDescriptor*> fields_;
  // We rely on the default copy constructor and operator= so this type can be
  // used in a vector.
};

// Reorder 'fields' so that if the fields are output into a c++ class in the new
// order, the alignment padding is minimized.  We try to do this while keeping
// each field as close as possible to its original position so that we don't
// reduce cache locality much for function that access each field in order.
void OptimizePadding(vector<const FieldDescriptor*>* fields) {
  // First divide fields into those that align to 1 byte, 4 bytes or 8 bytes.
  vector<FieldGroup> aligned_to_1, aligned_to_4, aligned_to_8;
  for (int i = 0; i < fields->size(); ++i) {
    switch (EstimateAlignmentSize((*fields)[i])) {
      case 1: aligned_to_1.push_back(FieldGroup(i, (*fields)[i])); break;
      case 4: aligned_to_4.push_back(FieldGroup(i, (*fields)[i])); break;
      case 8: aligned_to_8.push_back(FieldGroup(i, (*fields)[i])); break;
      default:
        GOOGLE_LOG(FATAL) << "Unknown alignment size.";
    }
  }

  // Now group fields aligned to 1 byte into sets of 4, and treat those like a
  // single field aligned to 4 bytes.
  for (int i = 0; i < aligned_to_1.size(); i += 4) {
    FieldGroup field_group;
    for (int j = i; j < aligned_to_1.size() && j < i + 4; ++j) {
      field_group.Append(aligned_to_1[j]);
    }
    aligned_to_4.push_back(field_group);
  }
  // Sort by preferred location to keep fields as close to their original
  // location as possible.
  sort(aligned_to_4.begin(), aligned_to_4.end());

  // Now group fields aligned to 4 bytes (or the 4-field groups created above)
  // into pairs, and treat those like a single field aligned to 8 bytes.
  for (int i = 0; i < aligned_to_4.size(); i += 2) {
    FieldGroup field_group;
    for (int j = i; j < aligned_to_4.size() && j < i + 2; ++j) {
      field_group.Append(aligned_to_4[j]);
    }
    if (i == aligned_to_4.size() - 1) {
      // Move incomplete 4-byte block to the end.
      field_group.SetPreferredLocation(fields->size() + 1);
    }
    aligned_to_8.push_back(field_group);
  }
  // Sort by preferred location to keep fields as close to their original
  // location as possible.
  sort(aligned_to_8.begin(), aligned_to_8.end());

  // Now pull out all the FieldDescriptors in order.
  fields->clear();
  for (int i = 0; i < aligned_to_8.size(); ++i) {
    fields->insert(fields->end(),
                   aligned_to_8[i].fields().begin(),
                   aligned_to_8[i].fields().end());
  }
}

}

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

MessageGenerator::MessageGenerator(const Descriptor* descriptor,
                                   const Options& options)
  : descriptor_(descriptor),
    classname_(ClassName(descriptor, false)),
    options_(options),
    field_generators_(descriptor, options),
    nested_generators_(new scoped_ptr<MessageGenerator>[
      descriptor->nested_type_count()]),
    enum_generators_(new scoped_ptr<EnumGenerator>[
      descriptor->enum_type_count()]),
    extension_generators_(new scoped_ptr<ExtensionGenerator>[
      descriptor->extension_count()]) {

  for (int i = 0; i < descriptor->nested_type_count(); i++) {
    nested_generators_[i].reset(
      new MessageGenerator(descriptor->nested_type(i), options));
  }

  for (int i = 0; i < descriptor->enum_type_count(); i++) {
    enum_generators_[i].reset(
      new EnumGenerator(descriptor->enum_type(i), options));
  }

  for (int i = 0; i < descriptor->extension_count(); i++) {
    extension_generators_[i].reset(
      new ExtensionGenerator(descriptor->extension(i), options));
  }
}

MessageGenerator::~MessageGenerator() {}

void MessageGenerator::
GenerateForwardDeclaration(io::Printer* printer) {
  printer->Print("class $classname$;\n",
                 "classname", classname_);

  for (int i = 0; i < descriptor_->nested_type_count(); i++) {
    nested_generators_[i]->GenerateForwardDeclaration(printer);
  }
}

void MessageGenerator::
GenerateEnumDefinitions(io::Printer* printer) {
  for (int i = 0; i < descriptor_->nested_type_count(); i++) {
    nested_generators_[i]->GenerateEnumDefinitions(printer);
  }

  for (int i = 0; i < descriptor_->enum_type_count(); i++) {
    enum_generators_[i]->GenerateDefinition(printer);
  }
}

void MessageGenerator::
GenerateGetEnumDescriptorSpecializations(io::Printer* printer) {
  for (int i = 0; i < descriptor_->nested_type_count(); i++) {
    nested_generators_[i]->GenerateGetEnumDescriptorSpecializations(printer);
  }
  for (int i = 0; i < descriptor_->enum_type_count(); i++) {
    enum_generators_[i]->GenerateGetEnumDescriptorSpecializations(printer);
  }
}

void MessageGenerator::
GenerateFieldAccessorDeclarations(io::Printer* printer) {
  for (int i = 0; i < descriptor_->field_count(); i++) {
    const FieldDescriptor* field = descriptor_->field(i);

    PrintFieldComment(printer, field);

    map<string, string> vars;
    SetCommonFieldVariables(field, &vars, options_);
    vars["constant_name"] = FieldConstantName(field);

    if (field->is_repeated()) {
      printer->Print(vars, "inline int $name$_size() const$deprecation$;\n");
    } else {
      printer->Print(vars, "inline bool has_$name$() const$deprecation$;\n");
    }

    printer->Print(vars, "inline void clear_$name$()$deprecation$;\n");
    printer->Print(vars, "static const int $constant_name$ = $number$;\n");

    // Generate type-specific accessor declarations.
    field_generators_.get(field).GenerateAccessorDeclarations(printer);

    printer->Print("\n");
  }

  if (descriptor_->extension_range_count() > 0) {
    // Generate accessors for extensions.  We just call a macro located in
    // extension_set.h since the accessors about 80 lines of static code.
    printer->Print(
      "GOOGLE_PROTOBUF_EXTENSION_ACCESSORS($classname$)\n",
      "classname", classname_);
  }
}

void MessageGenerator::
GenerateFieldAccessorDefinitions(io::Printer* printer) {
  printer->Print("// $classname$\n\n", "classname", classname_);

  for (int i = 0; i < descriptor_->field_count(); i++) {
    const FieldDescriptor* field = descriptor_->field(i);

    PrintFieldComment(printer, field);

    map<string, string> vars;
    SetCommonFieldVariables(field, &vars, options_);

    // Generate has_$name$() or $name$_size().
    if (field->is_repeated()) {
      printer->Print(vars,
        "inline int $classname$::$name$_size() const {\n"
        "  return $name$_.size();\n"
        "}\n");
    } else {
      // Singular field.
      char buffer[kFastToBufferSize];
      vars["has_array_index"] = SimpleItoa(field->index() / 32);
      vars["has_mask"] = FastHex32ToBuffer(1u << (field->index() % 32), buffer);
      printer->Print(vars,
        "inline bool $classname$::has_$name$() const {\n"
        "  return (_has_bits_[$has_array_index$] & 0x$has_mask$u) != 0;\n"
        "}\n"
        "inline void $classname$::set_has_$name$() {\n"
        "  _has_bits_[$has_array_index$] |= 0x$has_mask$u;\n"
        "}\n"
        "inline void $classname$::clear_has_$name$() {\n"
        "  _has_bits_[$has_array_index$] &= ~0x$has_mask$u;\n"
        "}\n"
        );
    }

    // Generate clear_$name$()
    printer->Print(vars,
      "inline void $classname$::clear_$name$() {\n");

    printer->Indent();
    field_generators_.get(field).GenerateClearingCode(printer);
    printer->Outdent();

    if (!field->is_repeated()) {
      printer->Print(vars,
                     "  clear_has_$name$();\n");
    }

    printer->Print("}\n");

    // Generate type-specific accessors.
    field_generators_.get(field).GenerateInlineAccessorDefinitions(printer);

    printer->Print("\n");
  }
}

void MessageGenerator::
GenerateClassDefinition(io::Printer* printer) {
  for (int i = 0; i < descriptor_->nested_type_count(); i++) {
    nested_generators_[i]->GenerateClassDefinition(printer);
    printer->Print("\n");
    printer->Print(kThinSeparator);
    printer->Print("\n");
  }

  map<string, string> vars;
  vars["classname"] = classname_;
  vars["field_count"] = SimpleItoa(descriptor_->field_count());
  if (options_.dllexport_decl.empty()) {
    vars["dllexport"] = "";
  } else {
    vars["dllexport"] = options_.dllexport_decl + " ";
  }
  vars["superclass"] = SuperClassName(descriptor_);

  printer->Print(vars,
    "class $dllexport$$classname$ : public $superclass$ {\n"
    " public:\n");
  printer->Indent();

  printer->Print(vars,
    "$classname$();\n"
    "virtual ~$classname$();\n"
    "\n"
    "$classname$(const $classname$& from);\n"
    "\n"
    "inline $classname$& operator=(const $classname$& from) {\n"
    "  CopyFrom(from);\n"
    "  return *this;\n"
    "}\n"
    "\n");

  if (HasUnknownFields(descriptor_->file())) {
    printer->Print(
      "inline const ::google::protobuf::UnknownFieldSet& unknown_fields() const {\n"
      "  return _unknown_fields_;\n"
      "}\n"
      "\n"
      "inline ::google::protobuf::UnknownFieldSet* mutable_unknown_fields() {\n"
      "  return &_unknown_fields_;\n"
      "}\n"
      "\n");
  }

  // Only generate this member if it's not disabled.
  if (HasDescriptorMethods(descriptor_->file()) &&
      !descriptor_->options().no_standard_descriptor_accessor()) {
    printer->Print(vars,
      "static const ::google::protobuf::Descriptor* descriptor();\n");
  }

  printer->Print(vars,
    "static const $classname$& default_instance();\n"
    "\n");

  if (!StaticInitializersForced(descriptor_->file())) {
    printer->Print(vars,
      "#ifdef GOOGLE_PROTOBUF_NO_STATIC_INITIALIZER\n"
      "// Returns the internal default instance pointer. This function can\n"
      "// return NULL thus should not be used by the user. This is intended\n"
      "// for Protobuf internal code. Please use default_instance() declared\n"
      "// above instead.\n"
      "static inline const $classname$* internal_default_instance() {\n"
      "  return default_instance_;\n"
      "}\n"
      "#endif\n"
      "\n");
  }


  printer->Print(vars,
    "void Swap($classname$* other);\n"
    "\n"
    "// implements Message ----------------------------------------------\n"
    "\n"
    "$classname$* New() const;\n");

  if (HasGeneratedMethods(descriptor_->file())) {
    if (HasDescriptorMethods(descriptor_->file())) {
      printer->Print(vars,
        "void CopyFrom(const ::google::protobuf::Message& from);\n"
        "void MergeFrom(const ::google::protobuf::Message& from);\n");
    } else {
      printer->Print(vars,
        "void CheckTypeAndMergeFrom(const ::google::protobuf::MessageLite& from);\n");
    }

    printer->Print(vars,
      "void CopyFrom(const $classname$& from);\n"
      "void MergeFrom(const $classname$& from);\n"
      "void Clear();\n"
      "bool IsInitialized() const;\n"
      "\n"
      "int ByteSize() const;\n"
      "bool MergePartialFromCodedStream(\n"
      "    ::google::protobuf::io::CodedInputStream* input);\n"
      "void SerializeWithCachedSizes(\n"
      "    ::google::protobuf::io::CodedOutputStream* output) const;\n");
    if (HasFastArraySerialization(descriptor_->file())) {
      printer->Print(
        "::google::protobuf::uint8* SerializeWithCachedSizesToArray(::google::protobuf::uint8* output) const;\n");
    }
  }

  printer->Print(vars,
    "int GetCachedSize() const { return _cached_size_; }\n"
    "private:\n"
    "void SharedCtor();\n"
    "void SharedDtor();\n"
    "void SetCachedSize(int size) const;\n"
    "public:\n"
    "\n");

  if (HasDescriptorMethods(descriptor_->file())) {
    printer->Print(
      "::google::protobuf::Metadata GetMetadata() const;\n"
      "\n");
  } else {
    printer->Print(
      "::std::string GetTypeName() const;\n"
      "\n");
  }

  printer->Print(
    "// nested types ----------------------------------------------------\n"
    "\n");

  // Import all nested message classes into this class's scope with typedefs.
  for (int i = 0; i < descriptor_->nested_type_count(); i++) {
    const Descriptor* nested_type = descriptor_->nested_type(i);
    printer->Print("typedef $nested_full_name$ $nested_name$;\n",
                   "nested_name", nested_type->name(),
                   "nested_full_name", ClassName(nested_type, false));
  }

  if (descriptor_->nested_type_count() > 0) {
    printer->Print("\n");
  }

  // Import all nested enums and their values into this class's scope with
  // typedefs and constants.
  for (int i = 0; i < descriptor_->enum_type_count(); i++) {
    enum_generators_[i]->GenerateSymbolImports(printer);
    printer->Print("\n");
  }

  printer->Print(
    "// accessors -------------------------------------------------------\n"
    "\n");

  // Generate accessor methods for all fields.
  GenerateFieldAccessorDeclarations(printer);

  // Declare extension identifiers.
  for (int i = 0; i < descriptor_->extension_count(); i++) {
    extension_generators_[i]->GenerateDeclaration(printer);
  }


  printer->Print(
    "// @@protoc_insertion_point(class_scope:$full_name$)\n",
    "full_name", descriptor_->full_name());

  // Generate private members.
  printer->Outdent();
  printer->Print(" private:\n");
  printer->Indent();


  for (int i = 0; i < descriptor_->field_count(); i++) {
    if (!descriptor_->field(i)->is_repeated()) {
      printer->Print(
        "inline void set_has_$name$();\n",
        "name", FieldName(descriptor_->field(i)));
      printer->Print(
        "inline void clear_has_$name$();\n",
        "name", FieldName(descriptor_->field(i)));
    }
  }
  printer->Print("\n");

  // To minimize padding, data members are divided into three sections:
  // (1) members assumed to align to 8 bytes
  // (2) members corresponding to message fields, re-ordered to optimize
  //     alignment.
  // (3) members assumed to align to 4 bytes.

  // Members assumed to align to 8 bytes:

  if (descriptor_->extension_range_count() > 0) {
    printer->Print(
      "::google::protobuf::internal::ExtensionSet _extensions_;\n"
      "\n");
  }

  if (HasUnknownFields(descriptor_->file())) {
    printer->Print(
      "::google::protobuf::UnknownFieldSet _unknown_fields_;\n"
      "\n");
  }

  // Field members:

  vector<const FieldDescriptor*> fields;
  for (int i = 0; i < descriptor_->field_count(); i++) {
    fields.push_back(descriptor_->field(i));
  }
  OptimizePadding(&fields);
  for (int i = 0; i < fields.size(); ++i) {
    field_generators_.get(fields[i]).GeneratePrivateMembers(printer);
  }

  // Members assumed to align to 4 bytes:

  // TODO(kenton):  Make _cached_size_ an atomic<int> when C++ supports it.
  printer->Print(
      "\n"
      "mutable int _cached_size_;\n");

  // Generate _has_bits_.
  if (descriptor_->field_count() > 0) {
    printer->Print(vars,
      "::google::protobuf::uint32 _has_bits_[($field_count$ + 31) / 32];\n"
      "\n");
  } else {
    // Zero-size arrays aren't technically allowed, and MSVC in particular
    // doesn't like them.  We still need to declare these arrays to make
    // other code compile.  Since this is an uncommon case, we'll just declare
    // them with size 1 and waste some space.  Oh well.
    printer->Print(
      "::google::protobuf::uint32 _has_bits_[1];\n"
      "\n");
  }

  // Declare AddDescriptors(), BuildDescriptors(), and ShutdownFile() as
  // friends so that they can access private static variables like
  // default_instance_ and reflection_.
  PrintHandlingOptionalStaticInitializers(
    descriptor_->file(), printer,
    // With static initializers.
    "friend void $dllexport_decl$ $adddescriptorsname$();\n",
    // Without.
    "friend void $dllexport_decl$ $adddescriptorsname$_impl();\n",
    // Vars.
    "dllexport_decl", options_.dllexport_decl,
    "adddescriptorsname",
    GlobalAddDescriptorsName(descriptor_->file()->name()));

  printer->Print(
    "friend void $assigndescriptorsname$();\n"
    "friend void $shutdownfilename$();\n"
    "\n",
    "assigndescriptorsname",
      GlobalAssignDescriptorsName(descriptor_->file()->name()),
    "shutdownfilename", GlobalShutdownFileName(descriptor_->file()->name()));

  printer->Print(
    "void InitAsDefaultInstance();\n"
    "static $classname$* default_instance_;\n",
    "classname", classname_);

  printer->Outdent();
  printer->Print(vars, "};");
}

void MessageGenerator::
GenerateInlineMethods(io::Printer* printer) {
  for (int i = 0; i < descriptor_->nested_type_count(); i++) {
    nested_generators_[i]->GenerateInlineMethods(printer);
    printer->Print(kThinSeparator);
    printer->Print("\n");
  }

  GenerateFieldAccessorDefinitions(printer);
}

void MessageGenerator::
GenerateDescriptorDeclarations(io::Printer* printer) {
  printer->Print(
    "const ::google::protobuf::Descriptor* $name$_descriptor_ = NULL;\n"
    "const ::google::protobuf::internal::GeneratedMessageReflection*\n"
    "  $name$_reflection_ = NULL;\n",
    "name", classname_);

  for (int i = 0; i < descriptor_->nested_type_count(); i++) {
    nested_generators_[i]->GenerateDescriptorDeclarations(printer);
  }

  for (int i = 0; i < descriptor_->enum_type_count(); i++) {
    printer->Print(
      "const ::google::protobuf::EnumDescriptor* $name$_descriptor_ = NULL;\n",
      "name", ClassName(descriptor_->enum_type(i), false));
  }
}

void MessageGenerator::
GenerateDescriptorInitializer(io::Printer* printer, int index) {
  // TODO(kenton):  Passing the index to this method is redundant; just use
  //   descriptor_->index() instead.
  map<string, string> vars;
  vars["classname"] = classname_;
  vars["index"] = SimpleItoa(index);

  // Obtain the descriptor from the parent's descriptor.
  if (descriptor_->containing_type() == NULL) {
    printer->Print(vars,
      "$classname$_descriptor_ = file->message_type($index$);\n");
  } else {
    vars["parent"] = ClassName(descriptor_->containing_type(), false);
    printer->Print(vars,
      "$classname$_descriptor_ = "
        "$parent$_descriptor_->nested_type($index$);\n");
  }

  // Generate the offsets.
  GenerateOffsets(printer);

  // Construct the reflection object.
  printer->Print(vars,
    "$classname$_reflection_ =\n"
    "  new ::google::protobuf::internal::GeneratedMessageReflection(\n"
    "    $classname$_descriptor_,\n"
    "    $classname$::default_instance_,\n"
    "    $classname$_offsets_,\n"
    "    GOOGLE_PROTOBUF_GENERATED_MESSAGE_FIELD_OFFSET($classname$, _has_bits_[0]),\n"
    "    GOOGLE_PROTOBUF_GENERATED_MESSAGE_FIELD_OFFSET("
      "$classname$, _unknown_fields_),\n");
  if (descriptor_->extension_range_count() > 0) {
    printer->Print(vars,
      "    GOOGLE_PROTOBUF_GENERATED_MESSAGE_FIELD_OFFSET("
        "$classname$, _extensions_),\n");
  } else {
    // No extensions.
    printer->Print(vars,
      "    -1,\n");
  }
  printer->Print(
    "    ::google::protobuf::DescriptorPool::generated_pool(),\n");
  printer->Print(vars,
    "    ::google::protobuf::MessageFactory::generated_factory(),\n");
  printer->Print(vars,
    "    sizeof($classname$));\n");

  // Handle nested types.
  for (int i = 0; i < descriptor_->nested_type_count(); i++) {
    nested_generators_[i]->GenerateDescriptorInitializer(printer, i);
  }

  for (int i = 0; i < descriptor_->enum_type_count(); i++) {
    enum_generators_[i]->GenerateDescriptorInitializer(printer, i);
  }
}

void MessageGenerator::
GenerateTypeRegistrations(io::Printer* printer) {
  // Register this message type with the message factory.
  printer->Print(
    "::google::protobuf::MessageFactory::InternalRegisterGeneratedMessage(\n"
    "  $classname$_descriptor_, &$classname$::default_instance());\n",
    "classname", classname_);

  // Handle nested types.
  for (int i = 0; i < descriptor_->nested_type_count(); i++) {
    nested_generators_[i]->GenerateTypeRegistrations(printer);
  }
}

void MessageGenerator::
GenerateDefaultInstanceAllocator(io::Printer* printer) {
  // Construct the default instances of all fields, as they will be used
  // when creating the default instance of the entire message.
  for (int i = 0; i < descriptor_->field_count(); i++) {
    field_generators_.get(descriptor_->field(i))
                     .GenerateDefaultInstanceAllocator(printer);
  }

  // Construct the default instance.  We can't call InitAsDefaultInstance() yet
  // because we need to make sure all default instances that this one might
  // depend on are constructed first.
  printer->Print(
    "$classname$::default_instance_ = new $classname$();\n",
    "classname", classname_);

  // Handle nested types.
  for (int i = 0; i < descriptor_->nested_type_count(); i++) {
    nested_generators_[i]->GenerateDefaultInstanceAllocator(printer);
  }

}

void MessageGenerator::
GenerateDefaultInstanceInitializer(io::Printer* printer) {
  printer->Print(
    "$classname$::default_instance_->InitAsDefaultInstance();\n",
    "classname", classname_);

  // Register extensions.
  for (int i = 0; i < descriptor_->extension_count(); i++) {
    extension_generators_[i]->GenerateRegistration(printer);
  }

  // Handle nested types.
  for (int i = 0; i < descriptor_->nested_type_count(); i++) {
    nested_generators_[i]->GenerateDefaultInstanceInitializer(printer);
  }
}

void MessageGenerator::
GenerateShutdownCode(io::Printer* printer) {
  printer->Print(
    "delete $classname$::default_instance_;\n",
    "classname", classname_);

  if (HasDescriptorMethods(descriptor_->file())) {
    printer->Print(
      "delete $classname$_reflection_;\n",
      "classname", classname_);
  }

  // Handle default instances of fields.
  for (int i = 0; i < descriptor_->field_count(); i++) {
    field_generators_.get(descriptor_->field(i))
                     .GenerateShutdownCode(printer);
  }

  // Handle nested types.
  for (int i = 0; i < descriptor_->nested_type_count(); i++) {
    nested_generators_[i]->GenerateShutdownCode(printer);
  }
}

void MessageGenerator::
GenerateClassMethods(io::Printer* printer) {
  for (int i = 0; i < descriptor_->enum_type_count(); i++) {
    enum_generators_[i]->GenerateMethods(printer);
  }

  for (int i = 0; i < descriptor_->nested_type_count(); i++) {
    nested_generators_[i]->GenerateClassMethods(printer);
    printer->Print("\n");
    printer->Print(kThinSeparator);
    printer->Print("\n");
  }

  // Generate non-inline field definitions.
  for (int i = 0; i < descriptor_->field_count(); i++) {
    field_generators_.get(descriptor_->field(i))
                     .GenerateNonInlineAccessorDefinitions(printer);
  }

  // Generate field number constants.
  printer->Print("#ifndef _MSC_VER\n");
  for (int i = 0; i < descriptor_->field_count(); i++) {
    const FieldDescriptor *field = descriptor_->field(i);
    printer->Print(
      "const int $classname$::$constant_name$;\n",
      "classname", ClassName(FieldScope(field), false),
      "constant_name", FieldConstantName(field));
  }
  printer->Print(
    "#endif  // !_MSC_VER\n"
    "\n");

  // Define extension identifiers.
  for (int i = 0; i < descriptor_->extension_count(); i++) {
    extension_generators_[i]->GenerateDefinition(printer);
  }

  GenerateStructors(printer);
  printer->Print("\n");

  if (HasGeneratedMethods(descriptor_->file())) {
    GenerateClear(printer);
    printer->Print("\n");

    GenerateMergeFromCodedStream(printer);
    printer->Print("\n");

    GenerateSerializeWithCachedSizes(printer);
    printer->Print("\n");

    if (HasFastArraySerialization(descriptor_->file())) {
      GenerateSerializeWithCachedSizesToArray(printer);
      printer->Print("\n");
    }

    GenerateByteSize(printer);
    printer->Print("\n");

    GenerateMergeFrom(printer);
    printer->Print("\n");

    GenerateCopyFrom(printer);
    printer->Print("\n");

    GenerateIsInitialized(printer);
    printer->Print("\n");
  }

  GenerateSwap(printer);
  printer->Print("\n");

  if (HasDescriptorMethods(descriptor_->file())) {
    printer->Print(
      "::google::protobuf::Metadata $classname$::GetMetadata() const {\n"
      "  protobuf_AssignDescriptorsOnce();\n"
      "  ::google::protobuf::Metadata metadata;\n"
      "  metadata.descriptor = $classname$_descriptor_;\n"
      "  metadata.reflection = $classname$_reflection_;\n"
      "  return metadata;\n"
      "}\n"
      "\n",
      "classname", classname_);
  } else {
    printer->Print(
      "::std::string $classname$::GetTypeName() const {\n"
      "  return \"$type_name$\";\n"
      "}\n"
      "\n",
      "classname", classname_,
      "type_name", descriptor_->full_name());
  }

}

void MessageGenerator::
GenerateOffsets(io::Printer* printer) {
  printer->Print(
    "static const int $classname$_offsets_[$field_count$] = {\n",
    "classname", classname_,
    "field_count", SimpleItoa(max(1, descriptor_->field_count())));
  printer->Indent();

  for (int i = 0; i < descriptor_->field_count(); i++) {
    const FieldDescriptor* field = descriptor_->field(i);
    printer->Print(
      "GOOGLE_PROTOBUF_GENERATED_MESSAGE_FIELD_OFFSET($classname$, $name$_),\n",
      "classname", classname_,
      "name", FieldName(field));
  }

  printer->Outdent();
  printer->Print("};\n");
}

void MessageGenerator::
GenerateSharedConstructorCode(io::Printer* printer) {
  printer->Print(
    "void $classname$::SharedCtor() {\n",
    "classname", classname_);
  printer->Indent();

  printer->Print(
    "_cached_size_ = 0;\n");

  for (int i = 0; i < descriptor_->field_count(); i++) {
    field_generators_.get(descriptor_->field(i))
                     .GenerateConstructorCode(printer);
  }

  printer->Print(
    "::memset(_has_bits_, 0, sizeof(_has_bits_));\n");

  printer->Outdent();
  printer->Print("}\n\n");
}

void MessageGenerator::
GenerateSharedDestructorCode(io::Printer* printer) {
  printer->Print(
    "void $classname$::SharedDtor() {\n",
    "classname", classname_);
  printer->Indent();
  // Write the destructors for each field.
  for (int i = 0; i < descriptor_->field_count(); i++) {
    field_generators_.get(descriptor_->field(i))
                     .GenerateDestructorCode(printer);
  }

  PrintHandlingOptionalStaticInitializers(
    descriptor_->file(), printer,
    // With static initializers.
    "if (this != default_instance_) {\n",
    // Without.
    "if (this != &default_instance()) {\n");

  // We need to delete all embedded messages.
  // TODO(kenton):  If we make unset messages point at default instances
  //   instead of NULL, then it would make sense to move this code into
  //   MessageFieldGenerator::GenerateDestructorCode().
  for (int i = 0; i < descriptor_->field_count(); i++) {
    const FieldDescriptor* field = descriptor_->field(i);

    if (!field->is_repeated() &&
        field->cpp_type() == FieldDescriptor::CPPTYPE_MESSAGE) {
      printer->Print("  delete $name$_;\n",
                     "name", FieldName(field));
    }
  }

  printer->Outdent();
  printer->Print(
    "  }\n"
    "}\n"
    "\n");
}

void MessageGenerator::
GenerateStructors(io::Printer* printer) {
  string superclass = SuperClassName(descriptor_);

  // Generate the default constructor.
  printer->Print(
    "$classname$::$classname$()\n"
    "  : $superclass$() {\n"
    "  SharedCtor();\n"
    "}\n",
    "classname", classname_,
    "superclass", superclass);

  printer->Print(
    "\n"
    "void $classname$::InitAsDefaultInstance() {\n",
    "classname", classname_);

  // The default instance needs all of its embedded message pointers
  // cross-linked to other default instances.  We can't do this initialization
  // in the constructor because some other default instances may not have been
  // constructed yet at that time.
  // TODO(kenton):  Maybe all message fields (even for non-default messages)
  //   should be initialized to point at default instances rather than NULL?
  for (int i = 0; i < descriptor_->field_count(); i++) {
    const FieldDescriptor* field = descriptor_->field(i);

    if (!field->is_repeated() &&
        field->cpp_type() == FieldDescriptor::CPPTYPE_MESSAGE) {
      PrintHandlingOptionalStaticInitializers(
        descriptor_->file(), printer,
        // With static initializers.
        "  $name$_ = const_cast< $type$*>(&$type$::default_instance());\n",
        // Without.
        "  $name$_ = const_cast< $type$*>(\n"
        "      $type$::internal_default_instance());\n",
        // Vars.
        "name", FieldName(field),
        "type", FieldMessageTypeName(field));
    }
  }
  printer->Print(
    "}\n"
    "\n");

  // Generate the copy constructor.
  printer->Print(
    "$classname$::$classname$(const $classname$& from)\n"
    "  : $superclass$() {\n"
    "  SharedCtor();\n"
    "  MergeFrom(from);\n"
    "}\n"
    "\n",
    "classname", classname_,
    "superclass", superclass);

  // Generate the shared constructor code.
  GenerateSharedConstructorCode(printer);

  // Generate the destructor.
  printer->Print(
    "$classname$::~$classname$() {\n"
    "  SharedDtor();\n"
    "}\n"
    "\n",
    "classname", classname_);

  // Generate the shared destructor code.
  GenerateSharedDestructorCode(printer);

  // Generate SetCachedSize.
  printer->Print(
    "void $classname$::SetCachedSize(int size) const {\n"
    "  GOOGLE_SAFE_CONCURRENT_WRITES_BEGIN();\n"
    "  _cached_size_ = size;\n"
    "  GOOGLE_SAFE_CONCURRENT_WRITES_END();\n"
    "}\n",
    "classname", classname_);

  // Only generate this member if it's not disabled.
  if (HasDescriptorMethods(descriptor_->file()) &&
      !descriptor_->options().no_standard_descriptor_accessor()) {
    printer->Print(
      "const ::google::protobuf::Descriptor* $classname$::descriptor() {\n"
      "  protobuf_AssignDescriptorsOnce();\n"
      "  return $classname$_descriptor_;\n"
      "}\n"
      "\n",
      "classname", classname_,
      "adddescriptorsname",
      GlobalAddDescriptorsName(descriptor_->file()->name()));
  }

  printer->Print(
    "const $classname$& $classname$::default_instance() {\n",
    "classname", classname_);

  PrintHandlingOptionalStaticInitializers(
    descriptor_->file(), printer,
    // With static initializers.
    "  if (default_instance_ == NULL) $adddescriptorsname$();\n",
    // Without.
    "  $adddescriptorsname$();\n",
    // Vars.
    "adddescriptorsname",
    GlobalAddDescriptorsName(descriptor_->file()->name()));

  printer->Print(
    "  return *default_instance_;\n"
    "}\n"
    "\n"
    "$classname$* $classname$::default_instance_ = NULL;\n"
    "\n"
    "$classname$* $classname$::New() const {\n"
    "  return new $classname$;\n"
    "}\n",
    "classname", classname_,
    "adddescriptorsname",
    GlobalAddDescriptorsName(descriptor_->file()->name()));
}

void MessageGenerator::
GenerateClear(io::Printer* printer) {
  printer->Print("void $classname$::Clear() {\n",
                 "classname", classname_);
  printer->Indent();

  int last_index = -1;

  if (descriptor_->extension_range_count() > 0) {
    printer->Print("_extensions_.Clear();\n");
  }

  for (int i = 0; i < descriptor_->field_count(); i++) {
    const FieldDescriptor* field = descriptor_->field(i);

    if (!field->is_repeated()) {
      // We can use the fact that _has_bits_ is a giant bitfield to our
      // advantage:  We can check up to 32 bits at a time for equality to
      // zero, and skip the whole range if so.  This can improve the speed
      // of Clear() for messages which contain a very large number of
      // optional fields of which only a few are used at a time.  Here,
      // we've chosen to check 8 bits at a time rather than 32.
      if (i / 8 != last_index / 8 || last_index < 0) {
        if (last_index >= 0) {
          printer->Outdent();
          printer->Print("}\n");
        }
        printer->Print(
          "if (_has_bits_[$index$ / 32] & (0xffu << ($index$ % 32))) {\n",
          "index", SimpleItoa(field->index()));
        printer->Indent();
      }
      last_index = i;

      // It's faster to just overwrite primitive types, but we should
      // only clear strings and messages if they were set.
      // TODO(kenton):  Let the CppFieldGenerator decide this somehow.
      bool should_check_bit =
        field->cpp_type() == FieldDescriptor::CPPTYPE_MESSAGE ||
        field->cpp_type() == FieldDescriptor::CPPTYPE_STRING;

      if (should_check_bit) {
        printer->Print(
          "if (has_$name$()) {\n",
          "name", FieldName(field));
        printer->Indent();
      }

      field_generators_.get(field).GenerateClearingCode(printer);

      if (should_check_bit) {
        printer->Outdent();
        printer->Print("}\n");
      }
    }
  }

  if (last_index >= 0) {
    printer->Outdent();
    printer->Print("}\n");
  }

  // Repeated fields don't use _has_bits_ so we clear them in a separate
  // pass.
  for (int i = 0; i < descriptor_->field_count(); i++) {
    const FieldDescriptor* field = descriptor_->field(i);

    if (field->is_repeated()) {
      field_generators_.get(field).GenerateClearingCode(printer);
    }
  }

  printer->Print(
    "::memset(_has_bits_, 0, sizeof(_has_bits_));\n");

  if (HasUnknownFields(descriptor_->file())) {
    printer->Print(
      "mutable_unknown_fields()->Clear();\n");
  }

  printer->Outdent();
  printer->Print("}\n");
}

void MessageGenerator::
GenerateSwap(io::Printer* printer) {
  // Generate the Swap member function.
  printer->Print("void $classname$::Swap($classname$* other) {\n",
                 "classname", classname_);
  printer->Indent();
  printer->Print("if (other != this) {\n");
  printer->Indent();

  if (HasGeneratedMethods(descriptor_->file())) {
    for (int i = 0; i < descriptor_->field_count(); i++) {
      const FieldDescriptor* field = descriptor_->field(i);
      field_generators_.get(field).GenerateSwappingCode(printer);
    }

    for (int i = 0; i < (descriptor_->field_count() + 31) / 32; ++i) {
      printer->Print("std::swap(_has_bits_[$i$], other->_has_bits_[$i$]);\n",
                     "i", SimpleItoa(i));
    }

    if (HasUnknownFields(descriptor_->file())) {
      printer->Print("_unknown_fields_.Swap(&other->_unknown_fields_);\n");
    }
    printer->Print("std::swap(_cached_size_, other->_cached_size_);\n");
    if (descriptor_->extension_range_count() > 0) {
      printer->Print("_extensions_.Swap(&other->_extensions_);\n");
    }
  } else {
    printer->Print("GetReflection()->Swap(this, other);");
  }

  printer->Outdent();
  printer->Print("}\n");
  printer->Outdent();
  printer->Print("}\n");
}

void MessageGenerator::
GenerateMergeFrom(io::Printer* printer) {
  if (HasDescriptorMethods(descriptor_->file())) {
    // Generate the generalized MergeFrom (aka that which takes in the Message
    // base class as a parameter).
    printer->Print(
      "void $classname$::MergeFrom(const ::google::protobuf::Message& from) {\n"
      "  GOOGLE_CHECK_NE(&from, this);\n",
      "classname", classname_);
    printer->Indent();

    // Cast the message to the proper type. If we find that the message is
    // *not* of the proper type, we can still call Merge via the reflection
    // system, as the GOOGLE_CHECK above ensured that we have the same descriptor
    // for each message.
    printer->Print(
      "const $classname$* source =\n"
      "  ::google::protobuf::internal::dynamic_cast_if_available<const $classname$*>(\n"
      "    &from);\n"
      "if (source == NULL) {\n"
      "  ::google::protobuf::internal::ReflectionOps::Merge(from, this);\n"
      "} else {\n"
      "  MergeFrom(*source);\n"
      "}\n",
      "classname", classname_);

    printer->Outdent();
    printer->Print("}\n\n");
  } else {
    // Generate CheckTypeAndMergeFrom().
    printer->Print(
      "void $classname$::CheckTypeAndMergeFrom(\n"
      "    const ::google::protobuf::MessageLite& from) {\n"
      "  MergeFrom(*::google::protobuf::down_cast<const $classname$*>(&from));\n"
      "}\n"
      "\n",
      "classname", classname_);
  }

  // Generate the class-specific MergeFrom, which avoids the GOOGLE_CHECK and cast.
  printer->Print(
    "void $classname$::MergeFrom(const $classname$& from) {\n"
    "  GOOGLE_CHECK_NE(&from, this);\n",
    "classname", classname_);
  printer->Indent();

  // Merge Repeated fields. These fields do not require a
  // check as we can simply iterate over them.
  for (int i = 0; i < descriptor_->field_count(); ++i) {
    const FieldDescriptor* field = descriptor_->field(i);

    if (field->is_repeated()) {
      field_generators_.get(field).GenerateMergingCode(printer);
    }
  }

  // Merge Optional and Required fields (after a _has_bit check).
  int last_index = -1;

  for (int i = 0; i < descriptor_->field_count(); ++i) {
    const FieldDescriptor* field = descriptor_->field(i);

    if (!field->is_repeated()) {
      // See above in GenerateClear for an explanation of this.
      if (i / 8 != last_index / 8 || last_index < 0) {
        if (last_index >= 0) {
          printer->Outdent();
          printer->Print("}\n");
        }
        printer->Print(
          "if (from._has_bits_[$index$ / 32] & (0xffu << ($index$ % 32))) {\n",
          "index", SimpleItoa(field->index()));
        printer->Indent();
      }

      last_index = i;

      printer->Print(
        "if (from.has_$name$()) {\n",
        "name", FieldName(field));
      printer->Indent();

      field_generators_.get(field).GenerateMergingCode(printer);

      printer->Outdent();
      printer->Print("}\n");
    }
  }

  if (last_index >= 0) {
    printer->Outdent();
    printer->Print("}\n");
  }

  if (descriptor_->extension_range_count() > 0) {
    printer->Print("_extensions_.MergeFrom(from._extensions_);\n");
  }

  if (HasUnknownFields(descriptor_->file())) {
    printer->Print(
      "mutable_unknown_fields()->MergeFrom(from.unknown_fields());\n");
  }

  printer->Outdent();
  printer->Print("}\n");
}

void MessageGenerator::
GenerateCopyFrom(io::Printer* printer) {
  if (HasDescriptorMethods(descriptor_->file())) {
    // Generate the generalized CopyFrom (aka that which takes in the Message
    // base class as a parameter).
    printer->Print(
      "void $classname$::CopyFrom(const ::google::protobuf::Message& from) {\n",
      "classname", classname_);
    printer->Indent();

    printer->Print(
      "if (&from == this) return;\n"
      "Clear();\n"
      "MergeFrom(from);\n");

    printer->Outdent();
    printer->Print("}\n\n");
  }

  // Generate the class-specific CopyFrom.
  printer->Print(
    "void $classname$::CopyFrom(const $classname$& from) {\n",
    "classname", classname_);
  printer->Indent();

  printer->Print(
    "if (&from == this) return;\n"
    "Clear();\n"
    "MergeFrom(from);\n");

  printer->Outdent();
  printer->Print("}\n");
}

void MessageGenerator::
GenerateMergeFromCodedStream(io::Printer* printer) {
  if (descriptor_->options().message_set_wire_format()) {
    // Special-case MessageSet.
    printer->Print(
      "bool $classname$::MergePartialFromCodedStream(\n"
      "    ::google::protobuf::io::CodedInputStream* input) {\n",
      "classname", classname_);

    PrintHandlingOptionalStaticInitializers(
      descriptor_->file(), printer,
      // With static initializers.
      "  return _extensions_.ParseMessageSet(input, default_instance_,\n"
      "                                      mutable_unknown_fields());\n",
      // Without.
      "  return _extensions_.ParseMessageSet(input, &default_instance(),\n"
      "                                      mutable_unknown_fields());\n",
      // Vars.
      "classname", classname_);

    printer->Print(
      "}\n");
    return;
  }

  printer->Print(
    "bool $classname$::MergePartialFromCodedStream(\n"
    "    ::google::protobuf::io::CodedInputStream* input) {\n"
    "#define DO_(EXPRESSION) if (!(EXPRESSION)) return false\n"
    "  ::google::protobuf::uint32 tag;\n"
    "  while ((tag = input->ReadTag()) != 0) {\n",
    "classname", classname_);

  printer->Indent();
  printer->Indent();

  if (descriptor_->field_count() > 0) {
    // We don't even want to print the switch() if we have no fields because
    // MSVC dislikes switch() statements that contain only a default value.

    // Note:  If we just switched on the tag rather than the field number, we
    // could avoid the need for the if() to check the wire type at the beginning
    // of each case.  However, this is actually a bit slower in practice as it
    // creates a jump table that is 8x larger and sparser, and meanwhile the
    // if()s are highly predictable.
    printer->Print(
      "switch (::google::protobuf::internal::WireFormatLite::GetTagFieldNumber(tag)) {\n");

    printer->Indent();

    scoped_array<const FieldDescriptor*> ordered_fields(
      SortFieldsByNumber(descriptor_));

    for (int i = 0; i < descriptor_->field_count(); i++) {
      const FieldDescriptor* field = ordered_fields[i];

      PrintFieldComment(printer, field);

      printer->Print(
        "case $number$: {\n",
        "number", SimpleItoa(field->number()));
      printer->Indent();
      const FieldGenerator& field_generator = field_generators_.get(field);

      // Emit code to parse the common, expected case.
      printer->Print(
        "if (::google::protobuf::internal::WireFormatLite::GetTagWireType(tag) ==\n"
        "    ::google::protobuf::internal::WireFormatLite::WIRETYPE_$wiretype$) {\n",
        "wiretype", kWireTypeNames[WireFormat::WireTypeForField(field)]);

      if (i > 0 || (field->is_repeated() && !field->options().packed())) {
        printer->Print(
          " parse_$name$:\n",
          "name", field->name());
      }

      printer->Indent();
      if (field->options().packed()) {
        field_generator.GenerateMergeFromCodedStreamWithPacking(printer);
      } else {
        field_generator.GenerateMergeFromCodedStream(printer);
      }
      printer->Outdent();

      // Emit code to parse unexpectedly packed or unpacked values.
      if (field->is_packable() && field->options().packed()) {
        printer->Print(
          "} else if (::google::protobuf::internal::WireFormatLite::GetTagWireType(tag)\n"
          "           == ::google::protobuf::internal::WireFormatLite::\n"
          "              WIRETYPE_$wiretype$) {\n",
          "wiretype",
          kWireTypeNames[WireFormat::WireTypeForFieldType(field->type())]);
        printer->Indent();
        field_generator.GenerateMergeFromCodedStream(printer);
        printer->Outdent();
      } else if (field->is_packable() && !field->options().packed()) {
        printer->Print(
          "} else if (::google::protobuf::internal::WireFormatLite::GetTagWireType(tag)\n"
          "           == ::google::protobuf::internal::WireFormatLite::\n"
          "              WIRETYPE_LENGTH_DELIMITED) {\n");
        printer->Indent();
        field_generator.GenerateMergeFromCodedStreamWithPacking(printer);
        printer->Outdent();
      }

      printer->Print(
        "} else {\n"
        "  goto handle_uninterpreted;\n"
        "}\n");

      // switch() is slow since it can't be predicted well.  Insert some if()s
      // here that attempt to predict the next tag.
      if (field->is_repeated() && !field->options().packed()) {
        // Expect repeats of this field.
        printer->Print(
          "if (input->ExpectTag($tag$)) goto parse_$name$;\n",
          "tag", SimpleItoa(WireFormat::MakeTag(field)),
          "name", field->name());
      }

      if (i + 1 < descriptor_->field_count()) {
        // Expect the next field in order.
        const FieldDescriptor* next_field = ordered_fields[i + 1];
        printer->Print(
          "if (input->ExpectTag($next_tag$)) goto parse_$next_name$;\n",
          "next_tag", SimpleItoa(WireFormat::MakeTag(next_field)),
          "next_name", next_field->name());
      } else {
        // Expect EOF.
        // TODO(kenton):  Expect group end-tag?
        printer->Print(
          "if (input->ExpectAtEnd()) return true;\n");
      }

      printer->Print(
        "break;\n");

      printer->Outdent();
      printer->Print("}\n\n");
    }

    printer->Print(
      "default: {\n"
      "handle_uninterpreted:\n");
    printer->Indent();
  }

  // Is this an end-group tag?  If so, this must be the end of the message.
  printer->Print(
    "if (::google::protobuf::internal::WireFormatLite::GetTagWireType(tag) ==\n"
    "    ::google::protobuf::internal::WireFormatLite::WIRETYPE_END_GROUP) {\n"
    "  return true;\n"
    "}\n");

  // Handle extension ranges.
  if (descriptor_->extension_range_count() > 0) {
    printer->Print(
      "if (");
    for (int i = 0; i < descriptor_->extension_range_count(); i++) {
      const Descriptor::ExtensionRange* range =
        descriptor_->extension_range(i);
      if (i > 0) printer->Print(" ||\n    ");

      uint32 start_tag = WireFormatLite::MakeTag(
        range->start, static_cast<WireFormatLite::WireType>(0));
      uint32 end_tag = WireFormatLite::MakeTag(
        range->end, static_cast<WireFormatLite::WireType>(0));

      if (range->end > FieldDescriptor::kMaxNumber) {
        printer->Print(
          "($start$u <= tag)",
          "start", SimpleItoa(start_tag));
      } else {
        printer->Print(
          "($start$u <= tag && tag < $end$u)",
          "start", SimpleItoa(start_tag),
          "end", SimpleItoa(end_tag));
      }
    }
    printer->Print(") {\n");
    if (HasUnknownFields(descriptor_->file())) {
      PrintHandlingOptionalStaticInitializers(
        descriptor_->file(), printer,
        // With static initializers.
        "  DO_(_extensions_.ParseField(tag, input, default_instance_,\n"
        "                              mutable_unknown_fields()));\n",
        // Without.
        "  DO_(_extensions_.ParseField(tag, input, &default_instance(),\n"
        "                              mutable_unknown_fields()));\n");
    } else {
      PrintHandlingOptionalStaticInitializers(
        descriptor_->file(), printer,
        // With static initializers.
        "  DO_(_extensions_.ParseField(tag, input, default_instance_, NULL));\n",
        // Without.
        "  DO_(_extensions_.ParseField(tag, input, &default_instance(), NULL));\n");
    }
    printer->Print(
      "  continue;\n"
      "}\n");
  }

  // We really don't recognize this tag.  Skip it.
  if (HasUnknownFields(descriptor_->file())) {
    printer->Print(
      "DO_(::google::protobuf::internal::WireFormatLite::SkipField(input, tag, mutable_unknown_fields()));\n");
  } else {
    printer->Print(
      "DO_(::google::protobuf::internal::WireFormatLite::SkipField(input, tag, NULL));\n");
  }

  if (descriptor_->field_count() > 0) {
    printer->Print("break;\n");
    printer->Outdent();
    printer->Print("}\n");    // default:
    printer->Outdent();
    printer->Print("}\n");    // switch
  }

  printer->Outdent();
  printer->Outdent();
  printer->Print(
    "  }\n"                   // while
    "  return true;\n"
    "#undef DO_\n"
    "}\n");
}

void MessageGenerator::GenerateSerializeOneField(
    io::Printer* printer, const FieldDescriptor* field, bool to_array) {
  PrintFieldComment(printer, field);

  if (!field->is_repeated()) {
    printer->Print(
      "if (has_$name$()) {\n",
      "name", FieldName(field));
    printer->Indent();
  }

  if (to_array) {
    field_generators_.get(field).GenerateSerializeWithCachedSizesToArray(
        printer);
  } else {
    field_generators_.get(field).GenerateSerializeWithCachedSizes(printer);
  }

  if (!field->is_repeated()) {
    printer->Outdent();
    printer->Print("}\n");
  }
  printer->Print("\n");
}

void MessageGenerator::GenerateSerializeOneExtensionRange(
    io::Printer* printer, const Descriptor::ExtensionRange* range,
    bool to_array) {
  map<string, string> vars;
  vars["start"] = SimpleItoa(range->start);
  vars["end"] = SimpleItoa(range->end);
  printer->Print(vars,
    "// Extension range [$start$, $end$)\n");
  if (to_array) {
    printer->Print(vars,
      "target = _extensions_.SerializeWithCachedSizesToArray(\n"
      "    $start$, $end$, target);\n\n");
  } else {
    printer->Print(vars,
      "_extensions_.SerializeWithCachedSizes(\n"
      "    $start$, $end$, output);\n\n");
  }
}

void MessageGenerator::
GenerateSerializeWithCachedSizes(io::Printer* printer) {
  if (descriptor_->options().message_set_wire_format()) {
    // Special-case MessageSet.
    printer->Print(
      "void $classname$::SerializeWithCachedSizes(\n"
      "    ::google::protobuf::io::CodedOutputStream* output) const {\n"
      "  _extensions_.SerializeMessageSetWithCachedSizes(output);\n",
      "classname", classname_);
    if (HasUnknownFields(descriptor_->file())) {
      printer->Print(
        "  ::google::protobuf::internal::WireFormatLite::SerializeUnknownMessageSetItems(\n"
        "      unknown_fields(), output);\n");
    }
    printer->Print(
      "}\n");
    return;
  }

  printer->Print(
    "void $classname$::SerializeWithCachedSizes(\n"
    "    ::google::protobuf::io::CodedOutputStream* output) const {\n",
    "classname", classname_);
  printer->Indent();

  GenerateSerializeWithCachedSizesBody(printer, false);

  printer->Outdent();
  printer->Print(
    "}\n");
}

void MessageGenerator::
GenerateSerializeWithCachedSizesToArray(io::Printer* printer) {
  if (descriptor_->options().message_set_wire_format()) {
    // Special-case MessageSet.
    printer->Print(
      "::google::protobuf::uint8* $classname$::SerializeWithCachedSizesToArray(\n"
      "    ::google::protobuf::uint8* target) const {\n"
      "  target =\n"
      "      _extensions_.SerializeMessageSetWithCachedSizesToArray(target);\n",
      "classname", classname_);
    if (HasUnknownFields(descriptor_->file())) {
      printer->Print(
        "  target = ::google::protobuf::internal::WireFormatLite::\n"
        "             SerializeUnknownMessageSetItemsToArray(\n"
        "               unknown_fields(), target);\n");
    }
    printer->Print(
      "  return target;\n"
      "}\n");
    return;
  }

  printer->Print(
    "::google::protobuf::uint8* $classname$::SerializeWithCachedSizesToArray(\n"
    "    ::google::protobuf::uint8* target) const {\n",
    "classname", classname_);
  printer->Indent();

  GenerateSerializeWithCachedSizesBody(printer, true);

  printer->Outdent();
  printer->Print(
    "  return target;\n"
    "}\n");
}

void MessageGenerator::
GenerateSerializeWithCachedSizesBody(io::Printer* printer, bool to_array) {
  scoped_array<const FieldDescriptor*> ordered_fields(
    SortFieldsByNumber(descriptor_));

  vector<const Descriptor::ExtensionRange*> sorted_extensions;
  for (int i = 0; i < descriptor_->extension_range_count(); ++i) {
    sorted_extensions.push_back(descriptor_->extension_range(i));
  }
  sort(sorted_extensions.begin(), sorted_extensions.end(),
       ExtensionRangeSorter());

  // Merge the fields and the extension ranges, both sorted by field number.
  int i, j;
  for (i = 0, j = 0;
       i < descriptor_->field_count() || j < sorted_extensions.size();
       ) {
    if (i == descriptor_->field_count()) {
      GenerateSerializeOneExtensionRange(printer,
                                         sorted_extensions[j++],
                                         to_array);
    } else if (j == sorted_extensions.size()) {
      GenerateSerializeOneField(printer, ordered_fields[i++], to_array);
    } else if (ordered_fields[i]->number() < sorted_extensions[j]->start) {
      GenerateSerializeOneField(printer, ordered_fields[i++], to_array);
    } else {
      GenerateSerializeOneExtensionRange(printer,
                                         sorted_extensions[j++],
                                         to_array);
    }
  }

  if (HasUnknownFields(descriptor_->file())) {
    printer->Print("if (!unknown_fields().empty()) {\n");
    printer->Indent();
    if (to_array) {
      printer->Print(
        "target = "
            "::google::protobuf::internal::WireFormatLite::SerializeUnknownFieldsToArray(\n"
        "    unknown_fields(), target);\n");
    } else {
      printer->Print(
        "::google::protobuf::internal::WireFormatLite::SerializeUnknownFields(\n"
        "    unknown_fields(), output);\n");
    }
    printer->Outdent();

    printer->Print(
      "}\n");
  }
}

void MessageGenerator::
GenerateByteSize(io::Printer* printer) {
  if (descriptor_->options().message_set_wire_format()) {
    // Special-case MessageSet.
    printer->Print(
      "int $classname$::ByteSize() const {\n"
      "  int total_size = _extensions_.MessageSetByteSize();\n",
      "classname", classname_);
    if (HasUnknownFields(descriptor_->file())) {
      printer->Print(
        "  total_size += ::google::protobuf::internal::WireFormatLite::\n"
        "      ComputeUnknownMessageSetItemsSize(unknown_fields());\n");
    }
    printer->Print(
      "  GOOGLE_SAFE_CONCURRENT_WRITES_BEGIN();\n"
      "  _cached_size_ = total_size;\n"
      "  GOOGLE_SAFE_CONCURRENT_WRITES_END();\n"
      "  return total_size;\n"
      "}\n");
    return;
  }

  printer->Print(
    "int $classname$::ByteSize() const {\n",
    "classname", classname_);
  printer->Indent();
  printer->Print(
    "int total_size = 0;\n"
    "\n");

  int last_index = -1;

  for (int i = 0; i < descriptor_->field_count(); i++) {
    const FieldDescriptor* field = descriptor_->field(i);

    if (!field->is_repeated()) {
      // See above in GenerateClear for an explanation of this.
      // TODO(kenton):  Share code?  Unclear how to do so without
      //   over-engineering.
      if ((i / 8) != (last_index / 8) ||
          last_index < 0) {
        if (last_index >= 0) {
          printer->Outdent();
          printer->Print("}\n");
        }
        printer->Print(
          "if (_has_bits_[$index$ / 32] & (0xffu << ($index$ % 32))) {\n",
          "index", SimpleItoa(field->index()));
        printer->Indent();
      }
      last_index = i;

      PrintFieldComment(printer, field);

      printer->Print(
        "if (has_$name$()) {\n",
        "name", FieldName(field));
      printer->Indent();

      field_generators_.get(field).GenerateByteSize(printer);

      printer->Outdent();
      printer->Print(
        "}\n"
        "\n");
    }
  }

  if (last_index >= 0) {
    printer->Outdent();
    printer->Print("}\n");
  }

  // Repeated fields don't use _has_bits_ so we count them in a separate
  // pass.
  for (int i = 0; i < descriptor_->field_count(); i++) {
    const FieldDescriptor* field = descriptor_->field(i);

    if (field->is_repeated()) {
      PrintFieldComment(printer, field);
      field_generators_.get(field).GenerateByteSize(printer);
      printer->Print("\n");
    }
  }

  if (descriptor_->extension_range_count() > 0) {
    printer->Print(
      "total_size += _extensions_.ByteSize();\n"
      "\n");
  }

  if (HasUnknownFields(descriptor_->file())) {
    printer->Print("if (!unknown_fields().empty()) {\n");
    printer->Indent();
    printer->Print(
      "total_size +=\n"
      "  ::google::protobuf::internal::WireFormatLite::ComputeUnknownFieldsSize(\n"
      "    unknown_fields());\n");
    printer->Outdent();
    printer->Print("}\n");
  }

  // We update _cached_size_ even though this is a const method.  In theory,
  // this is not thread-compatible, because concurrent writes have undefined
  // results.  In practice, since any concurrent writes will be writing the
  // exact same value, it works on all common processors.  In a future version
  // of C++, _cached_size_ should be made into an atomic<int>.
  printer->Print(
    "GOOGLE_SAFE_CONCURRENT_WRITES_BEGIN();\n"
    "_cached_size_ = total_size;\n"
    "GOOGLE_SAFE_CONCURRENT_WRITES_END();\n"
    "return total_size;\n");

  printer->Outdent();
  printer->Print("}\n");
}

void MessageGenerator::
GenerateIsInitialized(io::Printer* printer) {
  printer->Print(
    "bool $classname$::IsInitialized() const {\n",
    "classname", classname_);
  printer->Indent();

  // Check that all required fields in this message are set.  We can do this
  // most efficiently by checking 32 "has bits" at a time.
  int has_bits_array_size = (descriptor_->field_count() + 31) / 32;
  for (int i = 0; i < has_bits_array_size; i++) {
    uint32 mask = 0;
    for (int bit = 0; bit < 32; bit++) {
      int index = i * 32 + bit;
      if (index >= descriptor_->field_count()) break;
      const FieldDescriptor* field = descriptor_->field(index);

      if (field->is_required()) {
        mask |= 1 << bit;
      }
    }

    if (mask != 0) {
      char buffer[kFastToBufferSize];
      printer->Print(
        "if ((_has_bits_[$i$] & 0x$mask$) != 0x$mask$) return false;\n",
        "i", SimpleItoa(i),
        "mask", FastHex32ToBuffer(mask, buffer));
    }
  }

  // Now check that all embedded messages are initialized.
  printer->Print("\n");
  for (int i = 0; i < descriptor_->field_count(); i++) {
    const FieldDescriptor* field = descriptor_->field(i);
    if (field->cpp_type() == FieldDescriptor::CPPTYPE_MESSAGE &&
        !ShouldIgnoreRequiredFieldCheck(field) &&
        HasRequiredFields(field->message_type())) {
      if (field->is_repeated()) {
        printer->Print(
          "for (int i = 0; i < $name$_size(); i++) {\n"
          "  if (!this->$name$(i).IsInitialized()) return false;\n"
          "}\n",
          "name", FieldName(field));
      } else {
        printer->Print(
          "if (has_$name$()) {\n"
          "  if (!this->$name$().IsInitialized()) return false;\n"
          "}\n",
          "name", FieldName(field));
      }
    }
  }

  if (descriptor_->extension_range_count() > 0) {
    printer->Print(
      "\n"
      "if (!_extensions_.IsInitialized()) return false;");
  }

  printer->Outdent();
  printer->Print(
    "  return true;\n"
    "}\n");
}


}  // namespace cpp
}  // namespace compiler
}  // namespace protobuf
}  // namespace google
/* [<][>][^][v][top][bottom][index][help] */
root/third_party/protobuf/src/google/protobuf/compiler/cpp/cpp_message.cc

DEFINITIONS
