// 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: dweis@google.com (Daniel Weis)
//  Based on original Protocol Buffers design by
//  Sanjay Ghemawat, Jeff Dean, and others.

#include <google/protobuf/compiler/java/java_message_lite.h>

#include <algorithm>
#include <map>
#include <memory>
#include <vector>

#include <google/protobuf/compiler/java/java_context.h>
#include <google/protobuf/compiler/java/java_doc_comment.h>
#include <google/protobuf/compiler/java/java_enum_lite.h>
#include <google/protobuf/compiler/java/java_extension_lite.h>
#include <google/protobuf/compiler/java/java_generator_factory.h>
#include <google/protobuf/compiler/java/java_helpers.h>
#include <google/protobuf/compiler/java/java_message_builder.h>
#include <google/protobuf/compiler/java/java_message_builder_lite.h>
#include <google/protobuf/compiler/java/java_name_resolver.h>
#include <google/protobuf/descriptor.pb.h>
#include <google/protobuf/io/coded_stream.h>
#include <google/protobuf/io/printer.h>
#include <google/protobuf/wire_format.h>
#include <google/protobuf/stubs/strutil.h>
#include <google/protobuf/stubs/substitute.h>


namespace google {
namespace protobuf {
namespace compiler {
namespace java {

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

namespace {
bool EnableExperimentalRuntimeForLite() {
#ifdef PROTOBUF_EXPERIMENT
  return PROTOBUF_EXPERIMENT;
#else   // PROTOBUF_EXPERIMENT
  return false;
#endif  // !PROTOBUF_EXPERIMENT
}

std::string MapValueImmutableClassdName(const Descriptor* descriptor,
                                        ClassNameResolver* name_resolver) {
  const FieldDescriptor* value_field = descriptor->FindFieldByName("value");
  GOOGLE_CHECK_EQ(FieldDescriptor::TYPE_MESSAGE, value_field->type());
  return name_resolver->GetImmutableClassName(value_field->message_type());
}
}  // namespace

// ===================================================================
ImmutableMessageLiteGenerator::ImmutableMessageLiteGenerator(
    const Descriptor* descriptor, Context* context)
  : MessageGenerator(descriptor), context_(context),
    name_resolver_(context->GetNameResolver()),
    field_generators_(descriptor, context_) {
  GOOGLE_CHECK(!HasDescriptorMethods(descriptor->file(), context->EnforceLite()))
      << "Generator factory error: A lite message generator is used to "
         "generate non-lite messages.";
}

ImmutableMessageLiteGenerator::~ImmutableMessageLiteGenerator() {}

void ImmutableMessageLiteGenerator::GenerateStaticVariables(
    io::Printer* printer, int* bytecode_estimate) {
  // Generate static members for all nested types.
  for (int i = 0; i < descriptor_->nested_type_count(); i++) {
    // TODO(kenton):  Reuse MessageGenerator objects?
    ImmutableMessageLiteGenerator(descriptor_->nested_type(i), context_)
        .GenerateStaticVariables(printer, bytecode_estimate);
  }
}

int ImmutableMessageLiteGenerator::GenerateStaticVariableInitializers(
    io::Printer* printer) {
  int bytecode_estimate = 0;
  // Generate static member initializers for all nested types.
  for (int i = 0; i < descriptor_->nested_type_count(); i++) {
    // TODO(kenton):  Reuse MessageGenerator objects?
    bytecode_estimate +=
        ImmutableMessageLiteGenerator(descriptor_->nested_type(i), context_)
            .GenerateStaticVariableInitializers(printer);
  }
  return bytecode_estimate;
}

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

void ImmutableMessageLiteGenerator::GenerateInterface(io::Printer* printer) {
  MaybePrintGeneratedAnnotation(context_, printer, descriptor_,
                                /* immutable = */ true, "OrBuilder");
  if (descriptor_->extension_range_count() > 0) {
    printer->Print(
        "$deprecation$public interface ${$$classname$OrBuilder$}$ extends \n"
        "    $extra_interfaces$\n"
        "     com.google.protobuf.GeneratedMessageLite.\n"
        "          ExtendableMessageOrBuilder<\n"
        "              $classname$, $classname$.Builder> {\n",
        "deprecation", descriptor_->options().deprecated() ?
            "@java.lang.Deprecated " : "",
        "extra_interfaces", ExtraMessageOrBuilderInterfaces(descriptor_),
        "classname", descriptor_->name(),
        "{", "", "}", "");
  } else {
    printer->Print(
        "$deprecation$public interface ${$$classname$OrBuilder$}$ extends\n"
        "    $extra_interfaces$\n"
        "    com.google.protobuf.MessageLiteOrBuilder {\n",
        "deprecation", descriptor_->options().deprecated() ?
            "@java.lang.Deprecated " : "",
        "extra_interfaces", ExtraMessageOrBuilderInterfaces(descriptor_),
        "classname", descriptor_->name(),
        "{", "", "}", "");
  }
  printer->Annotate("{", "}", descriptor_);

  printer->Indent();
    for (int i = 0; i < descriptor_->field_count(); i++) {
      printer->Print("\n");
      field_generators_.get(descriptor_->field(i))
                       .GenerateInterfaceMembers(printer);
    }
    for (int i = 0; i < descriptor_->oneof_decl_count(); i++) {
      printer->Print(
          "\n"
          "public $classname$.$oneof_capitalized_name$Case "
          "get$oneof_capitalized_name$Case();\n",
          "oneof_capitalized_name",
          context_->GetOneofGeneratorInfo(
              descriptor_->oneof_decl(i))->capitalized_name,
          "classname",
          context_->GetNameResolver()->GetImmutableClassName(descriptor_));
    }
  printer->Outdent();

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

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

void ImmutableMessageLiteGenerator::Generate(io::Printer* printer) {
  bool is_own_file = IsOwnFile(descriptor_, /* immutable = */ true);

  std::map<std::string, std::string> variables;
  variables["static"] = is_own_file ? " " : " static ";
  variables["classname"] = descriptor_->name();
  variables["extra_interfaces"] = ExtraMessageInterfaces(descriptor_);
  variables["deprecation"] = descriptor_->options().deprecated()
      ? "@java.lang.Deprecated " : "";

  WriteMessageDocComment(printer, descriptor_);
  MaybePrintGeneratedAnnotation(context_, printer, descriptor_,
                                /* immutable = */ true);


  // The builder_type stores the super type name of the nested Builder class.
  std::string builder_type;
  if (descriptor_->extension_range_count() > 0) {
    printer->Print(variables,
      "$deprecation$public $static$final class $classname$ extends\n"
      "    com.google.protobuf.GeneratedMessageLite.ExtendableMessage<\n"
      "      $classname$, $classname$.Builder> implements\n"
      "    $extra_interfaces$\n"
      "    $classname$OrBuilder {\n");
    builder_type = strings::Substitute(
        "com.google.protobuf.GeneratedMessageLite.ExtendableBuilder<$0, ?>",
        name_resolver_->GetImmutableClassName(descriptor_));
  } else {
    printer->Print(variables,
        "$deprecation$public $static$final class $classname$ extends\n"
        "    com.google.protobuf.GeneratedMessageLite<\n"
        "        $classname$, $classname$.Builder> implements\n"
        "    $extra_interfaces$\n"
        "    $classname$OrBuilder {\n");

    builder_type = "com.google.protobuf.GeneratedMessageLite.Builder";
  }
  printer->Indent();

  GenerateConstructor(printer);

  // Nested types
  for (int i = 0; i < descriptor_->enum_type_count(); i++) {
    EnumLiteGenerator(descriptor_->enum_type(i), true, context_)
        .Generate(printer);
  }

  for (int i = 0; i < descriptor_->nested_type_count(); i++) {
    // Don't generate Java classes for map entry messages.
    if (IsMapEntry(descriptor_->nested_type(i))) continue;
    ImmutableMessageLiteGenerator messageGenerator(
        descriptor_->nested_type(i), context_);
    messageGenerator.GenerateInterface(printer);
    messageGenerator.Generate(printer);
  }

  // Integers for bit fields.
  int totalBits = 0;
  for (int i = 0; i < descriptor_->field_count(); i++) {
    totalBits +=
        field_generators_.get(descriptor_->field(i)).GetNumBitsForMessage();
  }
  int totalInts = (totalBits + 31) / 32;
  for (int i = 0; i < totalInts; i++) {
    printer->Print("private int $bit_field_name$;\n", "bit_field_name",
                   GetBitFieldName(i));
  }

  // oneof
  std::map<std::string, std::string> vars;
  for (int i = 0; i < descriptor_->oneof_decl_count(); i++) {
    const OneofDescriptor* oneof = descriptor_->oneof_decl(i);
    vars["oneof_name"] = context_->GetOneofGeneratorInfo(oneof)->name;
    vars["oneof_capitalized_name"] = context_->GetOneofGeneratorInfo(
        oneof)->capitalized_name;
    vars["oneof_index"] = StrCat(oneof->index());
    // oneofCase_ and oneof_
    printer->Print(vars,
      "private int $oneof_name$Case_ = 0;\n"
      "private java.lang.Object $oneof_name$_;\n");
    // OneofCase enum
    printer->Print(vars,
      "public enum $oneof_capitalized_name$Case\n"
      "    implements com.google.protobuf.Internal.EnumLite {\n");
    printer->Indent();
    for (int j = 0; j < oneof->field_count(); j++) {
      const FieldDescriptor* field = oneof->field(j);
      printer->Print("$field_name$($field_number$),\n", "field_name",
                     ToUpper(field->name()), "field_number",
                     StrCat(field->number()));
    }
    printer->Print(
      "$cap_oneof_name$_NOT_SET(0);\n",
      "cap_oneof_name",
      ToUpper(vars["oneof_name"]));
    printer->Print(vars,
      "private final int value;\n"
      "private $oneof_capitalized_name$Case(int value) {\n"
      "  this.value = value;\n"
      "}\n");
    printer->Print(vars,
      "/**\n"
      " * @deprecated Use {@link #forNumber(int)} instead.\n"
      " */\n"
      "@java.lang.Deprecated\n"
      "public static $oneof_capitalized_name$Case valueOf(int value) {\n"
      "  return forNumber(value);\n"
      "}\n"
      "\n"
      "public static $oneof_capitalized_name$Case forNumber(int value) {\n"
      "  switch (value) {\n");
    for (int j = 0; j < oneof->field_count(); j++) {
      const FieldDescriptor* field = oneof->field(j);
      printer->Print("    case $field_number$: return $field_name$;\n",
                     "field_number", StrCat(field->number()),
                     "field_name", ToUpper(field->name()));
    }
    printer->Print(
      "    case 0: return $cap_oneof_name$_NOT_SET;\n"
      "    default: return null;\n"
      "  }\n"
      "}\n"
      "@java.lang.Override\n"
      "public int getNumber() {\n"
      "  return this.value;\n"
      "}\n",
      "cap_oneof_name", ToUpper(vars["oneof_name"]));
    printer->Outdent();
    printer->Print("};\n\n");
    // oneofCase()
    printer->Print(vars,
      "@java.lang.Override\n"
      "public $oneof_capitalized_name$Case\n"
      "get$oneof_capitalized_name$Case() {\n"
      "  return $oneof_capitalized_name$Case.forNumber(\n"
      "      $oneof_name$Case_);\n"
      "}\n"
      "\n"
      "private void clear$oneof_capitalized_name$() {\n"
      "  $oneof_name$Case_ = 0;\n"
      "  $oneof_name$_ = null;\n"
      "}\n"
      "\n");
  }

  // Fields
  for (int i = 0; i < descriptor_->field_count(); i++) {
    printer->Print("public static final int $constant_name$ = $number$;\n",
                   "constant_name", FieldConstantName(descriptor_->field(i)),
                   "number", StrCat(descriptor_->field(i)->number()));
    field_generators_.get(descriptor_->field(i)).GenerateMembers(printer);
    printer->Print("\n");
  }

  GenerateMessageSerializationMethods(printer);
  GenerateParseFromMethods(printer);
  GenerateBuilder(printer);

  if (HasRequiredFields(descriptor_)) {
    // Memoizes whether the protocol buffer is fully initialized (has all
    // required fields). 0 means false, 1 means true, and all other values
    // mean not yet computed.
    printer->Print(
      "private byte memoizedIsInitialized = 2;\n");
  }

  printer->Print(
      "@java.lang.Override\n"
      "@java.lang.SuppressWarnings({\"unchecked\", \"fallthrough\"})\n"
      "protected final java.lang.Object dynamicMethod(\n"
      "    com.google.protobuf.GeneratedMessageLite.MethodToInvoke method,\n"
      "    java.lang.Object arg0, java.lang.Object arg1) {\n"
      "  switch (method) {\n"
      "    case NEW_MUTABLE_INSTANCE: {\n"
      "      return new $classname$();\n"
      "    }\n",
      "classname", name_resolver_->GetImmutableClassName(descriptor_));

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

  printer->Print(
    "case NEW_BUILDER: {\n");

  printer->Indent();
  GenerateDynamicMethodNewBuilder(printer);
  printer->Outdent();

  if (!EnableExperimentalRuntimeForLite()) {
    printer->Print(
      "}\n"
      "case IS_INITIALIZED: {\n");
    printer->Indent();
    GenerateDynamicMethodIsInitialized(printer);
    printer->Outdent();

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

    printer->Print(
      "case MAKE_IMMUTABLE: {\n");

    printer->Indent();
    GenerateDynamicMethodMakeImmutable(printer);
    printer->Outdent();

    printer->Print(
        "}\n"
        "case VISIT: {\n");

    printer->Indent();
    GenerateDynamicMethodVisit(printer);
    printer->Outdent();

    printer->Print(
        "}\n"
        "case MERGE_FROM_STREAM: {\n");

    printer->Indent();
    GenerateDynamicMethodMergeFromStream(printer);
    printer->Outdent();
  }


  printer->Print(
    "}\n"
    "// fall through\n"
    "case GET_DEFAULT_INSTANCE: {\n"
    "  return DEFAULT_INSTANCE;\n"
    "}\n"
    "case GET_PARSER: {\n"
    // Generally one would use the lazy initialization holder pattern for
    // manipulating static fields but that has exceptional cost on Android as
    // it will generate an extra class for every message. Instead, use the
    // double-check locking pattern which works just as well.
    //
    // The "parser" temporary mirrors the "PARSER" field to eliminate a read
    // at the final return statement.
    "  com.google.protobuf.Parser<$classname$> parser = PARSER;\n"
    "  if (parser == null) {\n"
    "    synchronized ($classname$.class) {\n"
    "      parser = PARSER;\n"
    "      if (parser == null) {\n"
    "        parser = new DefaultInstanceBasedParser(DEFAULT_INSTANCE);\n"
    "        PARSER = parser;\n"
    "      }\n"
    "    }\n"
    "  }\n"
    "  return parser;\n",
    "classname", name_resolver_->GetImmutableClassName(descriptor_));

  printer->Outdent();

  if (HasRequiredFields(descriptor_)) {
    printer->Print(
        "}\n"
        "case GET_MEMOIZED_IS_INITIALIZED: {\n"
        "  return memoizedIsInitialized;\n"
        "}\n"
        "case SET_MEMOIZED_IS_INITIALIZED: {\n"
        "  memoizedIsInitialized = (byte) (arg0 == null ? 0 : 1);\n"
        "  return null;\n"
        "}\n");
  } else {
    printer->Print(
        "}\n"
        "case GET_MEMOIZED_IS_INITIALIZED: {\n"
        "  return (byte) 1;\n"
        "}\n"
        "case SET_MEMOIZED_IS_INITIALIZED: {\n"
        "  return null;\n"
        "}\n");
  }

  printer->Outdent();
  printer->Print(
    "  }\n"
    "  throw new UnsupportedOperationException();\n"
    "}\n"
    "\n",
    "classname", name_resolver_->GetImmutableClassName(descriptor_));

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


  // Carefully initialize the default instance in such a way that it doesn't
  // conflict with other initialization.
  printer->Print(
    "private static final $classname$ DEFAULT_INSTANCE;\n",
    "classname", name_resolver_->GetImmutableClassName(descriptor_));

  printer->Print(
    "static {\n"
    "  // New instances are implicitly immutable so no need to make\n"
    "  // immutable.\n"
    "  DEFAULT_INSTANCE = new $classname$();\n"
    "}\n"
    "\n",
    "classname", descriptor_->name());
  if (EnableExperimentalRuntimeForLite()) {
    // Register the default instance in a map. This map will be used by
    // experimental runtime to lookup default instance given a class instance
    // without using Java reflection.
    printer->Print(
        "static {\n"
        "  com.google.protobuf.GeneratedMessageLite.registerDefaultInstance(\n"
        "    $classname$.class, DEFAULT_INSTANCE);\n"
        "}\n",
        "classname", descriptor_->name());
  }

  printer->Print(
      "public static $classname$ getDefaultInstance() {\n"
      "  return DEFAULT_INSTANCE;\n"
      "}\n"
      "\n",
      "classname", name_resolver_->GetImmutableClassName(descriptor_));

  // 'of' method for Wrappers
  if (IsWrappersProtoFile(descriptor_->file())) {
    printer->Print(
        "public static $classname$ of($field_type$ value) {\n"
        "  return newBuilder().setValue(value).build();\n"
        "}\n"
        "\n",
        "classname", name_resolver_->GetImmutableClassName(descriptor_),
        "field_type", PrimitiveTypeName(GetJavaType(descriptor_->field(0))));
  }

  GenerateParser(printer);

  // Extensions must be declared after the DEFAULT_INSTANCE is initialized
  // because the DEFAULT_INSTANCE is used by the extension to lazily retrieve
  // the outer class's FileDescriptor.
  for (int i = 0; i < descriptor_->extension_count(); i++) {
    ImmutableExtensionLiteGenerator(descriptor_->extension(i), context_)
        .Generate(printer);
  }


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


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

void ImmutableMessageLiteGenerator::
GenerateMessageSerializationMethods(io::Printer* printer) {
  if (EnableExperimentalRuntimeForLite()) {
    return;
  }

  std::unique_ptr<const FieldDescriptor * []> sorted_fields(
      SortFieldsByNumber(descriptor_));

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

  printer->Print(
    "@java.lang.Override\n"
    "public void writeTo(com.google.protobuf.CodedOutputStream output)\n"
    "                    throws java.io.IOException {\n");
  printer->Indent();
  if (HasPackedFields(descriptor_)) {
    // writeTo(CodedOutputStream output) might be invoked without
    // getSerializedSize() ever being called, but we need the memoized
    // sizes in case this message has packed fields. Rather than emit checks
    // for each packed field, just call getSerializedSize() up front. In most
    // cases, getSerializedSize() will have already been called anyway by one
    // of the wrapper writeTo() methods, making this call cheap.
    printer->Print("getSerializedSize();\n");
  }

  if (descriptor_->extension_range_count() > 0) {
    if (descriptor_->options().message_set_wire_format()) {
      printer->Print(
          "com.google.protobuf.GeneratedMessageLite\n"
          "  .ExtendableMessage<$classname$, $classname$.Builder>\n"
          "    .ExtensionWriter extensionWriter =\n"
          "      newMessageSetExtensionWriter();\n",
          "classname", name_resolver_->GetImmutableClassName(descriptor_));
    } else {
      printer->Print(
          "com.google.protobuf.GeneratedMessageLite\n"
          "  .ExtendableMessage<$classname$, $classname$.Builder>\n"
          "    .ExtensionWriter extensionWriter =\n"
          "      newExtensionWriter();\n",
          "classname", name_resolver_->GetImmutableClassName(descriptor_));
    }
  }

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

  if (descriptor_->options().message_set_wire_format()) {
    printer->Print("unknownFields.writeAsMessageSetTo(output);\n");
  } else {
    printer->Print("unknownFields.writeTo(output);\n");
  }

  printer->Outdent();
  printer->Print(
      "}\n"
      "\n"
      "@java.lang.Override\n"
      "public int getSerializedSize() {\n"
      "  int size = memoizedSerializedSize;\n"
      "  if (size != -1) return size;\n"
      "\n");
  printer->Indent();
  printer->Print(
      "size = 0;\n");

  for (int i = 0; i < descriptor_->field_count(); i++) {
    field_generators_.get(sorted_fields[i]).GenerateSerializedSizeCode(printer);
  }

  if (descriptor_->extension_range_count() > 0) {
    if (descriptor_->options().message_set_wire_format()) {
      printer->Print("size += extensionsSerializedSizeAsMessageSet();\n");
    } else {
      printer->Print("size += extensionsSerializedSize();\n");
    }
  }

  if (descriptor_->options().message_set_wire_format()) {
    printer->Print("size += unknownFields.getSerializedSizeAsMessageSet();\n");
  } else {
    printer->Print("size += unknownFields.getSerializedSize();\n");
  }

  printer->Print(
      "memoizedSerializedSize = size;\n"
      "return size;\n");

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

void ImmutableMessageLiteGenerator::
GenerateParseFromMethods(io::Printer* printer) {
  // Note:  These are separate from GenerateMessageSerializationMethods()
  //   because they need to be generated even for messages that are optimized
  //   for code size.
  printer->Print(
    "public static $classname$ parseFrom(\n"
    "    java.nio.ByteBuffer data)\n"
    "    throws com.google.protobuf.InvalidProtocolBufferException {\n"
    "  return com.google.protobuf.GeneratedMessageLite.parseFrom(\n"
    "      DEFAULT_INSTANCE, data);\n"
    "}\n"
    "public static $classname$ parseFrom(\n"
    "    java.nio.ByteBuffer data,\n"
    "    com.google.protobuf.ExtensionRegistryLite extensionRegistry)\n"
    "    throws com.google.protobuf.InvalidProtocolBufferException {\n"
    "  return com.google.protobuf.GeneratedMessageLite.parseFrom(\n"
    "      DEFAULT_INSTANCE, data, extensionRegistry);\n"
    "}\n"
    "public static $classname$ parseFrom(\n"
    "    com.google.protobuf.ByteString data)\n"
    "    throws com.google.protobuf.InvalidProtocolBufferException {\n"
    "  return com.google.protobuf.GeneratedMessageLite.parseFrom(\n"
    "      DEFAULT_INSTANCE, data);\n"
    "}\n"
    "public static $classname$ parseFrom(\n"
    "    com.google.protobuf.ByteString data,\n"
    "    com.google.protobuf.ExtensionRegistryLite extensionRegistry)\n"
    "    throws com.google.protobuf.InvalidProtocolBufferException {\n"
    "  return com.google.protobuf.GeneratedMessageLite.parseFrom(\n"
    "      DEFAULT_INSTANCE, data, extensionRegistry);\n"
    "}\n"
    "public static $classname$ parseFrom(byte[] data)\n"
    "    throws com.google.protobuf.InvalidProtocolBufferException {\n"
    "  return com.google.protobuf.GeneratedMessageLite.parseFrom(\n"
    "      DEFAULT_INSTANCE, data);\n"
    "}\n"
    "public static $classname$ parseFrom(\n"
    "    byte[] data,\n"
    "    com.google.protobuf.ExtensionRegistryLite extensionRegistry)\n"
    "    throws com.google.protobuf.InvalidProtocolBufferException {\n"
    "  return com.google.protobuf.GeneratedMessageLite.parseFrom(\n"
    "      DEFAULT_INSTANCE, data, extensionRegistry);\n"
    "}\n"
    "public static $classname$ parseFrom(java.io.InputStream input)\n"
    "    throws java.io.IOException {\n"
    "  return com.google.protobuf.GeneratedMessageLite.parseFrom(\n"
    "      DEFAULT_INSTANCE, input);\n"
    "}\n"
    "public static $classname$ parseFrom(\n"
    "    java.io.InputStream input,\n"
    "    com.google.protobuf.ExtensionRegistryLite extensionRegistry)\n"
    "    throws java.io.IOException {\n"
    "  return com.google.protobuf.GeneratedMessageLite.parseFrom(\n"
    "      DEFAULT_INSTANCE, input, extensionRegistry);\n"
    "}\n"
    "public static $classname$ parseDelimitedFrom(java.io.InputStream input)\n"
    "    throws java.io.IOException {\n"
    "  return parseDelimitedFrom(DEFAULT_INSTANCE, input);\n"
    "}\n"
    "public static $classname$ parseDelimitedFrom(\n"
    "    java.io.InputStream input,\n"
    "    com.google.protobuf.ExtensionRegistryLite extensionRegistry)\n"
    "    throws java.io.IOException {\n"
    "  return parseDelimitedFrom(DEFAULT_INSTANCE, input, extensionRegistry);\n"
    "}\n"
    "public static $classname$ parseFrom(\n"
    "    com.google.protobuf.CodedInputStream input)\n"
    "    throws java.io.IOException {\n"
    "  return com.google.protobuf.GeneratedMessageLite.parseFrom(\n"
    "      DEFAULT_INSTANCE, input);\n"
    "}\n"
    "public static $classname$ parseFrom(\n"
    "    com.google.protobuf.CodedInputStream input,\n"
    "    com.google.protobuf.ExtensionRegistryLite extensionRegistry)\n"
    "    throws java.io.IOException {\n"
    "  return com.google.protobuf.GeneratedMessageLite.parseFrom(\n"
    "      DEFAULT_INSTANCE, input, extensionRegistry);\n"
    "}\n"
    "\n",
    "classname", name_resolver_->GetImmutableClassName(descriptor_));
}

void ImmutableMessageLiteGenerator::GenerateSerializeOneField(
    io::Printer* printer, const FieldDescriptor* field) {
  field_generators_.get(field).GenerateSerializationCode(printer);
}

void ImmutableMessageLiteGenerator::GenerateSerializeOneExtensionRange(
    io::Printer* printer, const Descriptor::ExtensionRange* range) {
  printer->Print("extensionWriter.writeUntil($end$, output);\n", "end",
                 StrCat(range->end));
}

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

void ImmutableMessageLiteGenerator::GenerateBuilder(io::Printer* printer) {
  printer->Print(
      "public static Builder newBuilder() {\n"
      "  return (Builder) DEFAULT_INSTANCE.createBuilder();\n"
      "}\n"
      "public static Builder newBuilder($classname$ prototype) {\n"
      "  return (Builder) DEFAULT_INSTANCE.createBuilder(prototype);\n"
      "}\n"
      "\n",
      "classname", name_resolver_->GetImmutableClassName(descriptor_));

  MessageBuilderLiteGenerator builderGenerator(descriptor_, context_);
  builderGenerator.Generate(printer);
}

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

void ImmutableMessageLiteGenerator::GenerateDynamicMethodIsInitialized(
    io::Printer* printer) {
  // Returns null for false, DEFAULT_INSTANCE for true.
  if (!HasRequiredFields(descriptor_)) {
    printer->Print("return DEFAULT_INSTANCE;\n");
    return;
  }

  // TODO(xiaofeng): Remove this when b/64445758 is fixed. We don't need to
  // check memoizedIsInitialized here because the caller does that already,
  // but right now proguard proto shrinker asserts on the bytecode layout of
  // this code so it can't be removed until proguard is updated.
  printer->Print(
    "byte isInitialized = memoizedIsInitialized;\n"
    "if (isInitialized == 1) return DEFAULT_INSTANCE;\n"
    "if (isInitialized == 0) return null;\n"
    "\n"
    "boolean shouldMemoize = ((Boolean) arg0).booleanValue();\n");

  // Check that all required fields in this message are set.
  // TODO(kenton):  We can optimize this when we switch to putting all the
  //   "has" fields into a single bitfield.
  for (int i = 0; i < descriptor_->field_count(); i++) {
    const FieldDescriptor* field = descriptor_->field(i);
    const FieldGeneratorInfo* info = context_->GetFieldGeneratorInfo(field);

    if (field->is_required()) {
      printer->Print(
        "if (!has$name$()) {\n"
        "  return null;\n"
        "}\n",
        "name", info->capitalized_name);
    }
  }

  // Now check that all embedded messages are initialized.
  for (int i = 0; i < descriptor_->field_count(); i++) {
    const FieldDescriptor* field = descriptor_->field(i);
    const FieldGeneratorInfo* info = context_->GetFieldGeneratorInfo(field);
    if (GetJavaType(field) == JAVATYPE_MESSAGE &&
        HasRequiredFields(field->message_type())) {
      switch (field->label()) {
        case FieldDescriptor::LABEL_REQUIRED:
          printer->Print(
            "if (!get$name$().isInitialized()) {\n"
            "  return null;\n"
            "}\n",
            "type", name_resolver_->GetImmutableClassName(
                field->message_type()),
            "name", info->capitalized_name);
          break;
        case FieldDescriptor::LABEL_OPTIONAL:
          if (!SupportFieldPresence(descriptor_->file()) &&
              field->containing_oneof() != NULL) {
            const OneofDescriptor* oneof = field->containing_oneof();
            const OneofGeneratorInfo* oneof_info =
                context_->GetOneofGeneratorInfo(oneof);
            printer->Print("if ($oneof_name$Case_ == $field_number$) {\n",
                           "oneof_name", oneof_info->name, "field_number",
                           StrCat(field->number()));
          } else {
            printer->Print(
              "if (has$name$()) {\n",
              "name", info->capitalized_name);
          }
          printer->Print(
            "  if (!get$name$().isInitialized()) {\n"
            "    return null;\n"
            "  }\n"
            "}\n",
            "name", info->capitalized_name);
          break;
        case FieldDescriptor::LABEL_REPEATED:
          if (IsMapEntry(field->message_type())) {
            printer->Print(
              "for ($type$ item : get$name$Map().values()) {\n"
              "  if (!item.isInitialized()) {\n"
              "    return null;\n"
              "  }\n"
              "}\n",
              "type", MapValueImmutableClassdName(field->message_type(),
                                                  name_resolver_),
              "name", info->capitalized_name);
          } else {
            printer->Print(
              "for (int i = 0; i < get$name$Count(); i++) {\n"
              "  if (!get$name$(i).isInitialized()) {\n"
              "    return null;\n"
              "  }\n"
              "}\n",
              "type", name_resolver_->GetImmutableClassName(
                  field->message_type()),
              "name", info->capitalized_name);
          }
          break;
      }
    }
  }

  if (descriptor_->extension_range_count() > 0) {
    printer->Print(
      "if (!extensionsAreInitialized()) {\n"
      "  return null;\n"
      "}\n");
  }

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

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

void ImmutableMessageLiteGenerator::GenerateDynamicMethodMakeImmutable(
    io::Printer* printer) {

  // Output generation code for each field.
  for (int i = 0; i < descriptor_->field_count(); i++) {
    field_generators_.get(descriptor_->field(i))
        .GenerateDynamicMethodMakeImmutableCode(printer);
  }

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

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

void ImmutableMessageLiteGenerator::GenerateDynamicMethodNewBuilder(
    io::Printer* printer) {
  printer->Print(
    "return new Builder();\n");
}

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

void ImmutableMessageLiteGenerator::GenerateDynamicMethodVisit(
    io::Printer* printer) {
  printer->Print(
    "Visitor visitor = (Visitor) arg0;\n"
    "$classname$ other = ($classname$) arg1;\n",
    "classname", name_resolver_->GetImmutableClassName(descriptor_));

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

  // Merge oneof fields.
  for (int i = 0; i < descriptor_->oneof_decl_count(); ++i) {
    printer->Print(
      "switch (other.get$oneof_capitalized_name$Case()) {\n",
      "oneof_capitalized_name",
      context_->GetOneofGeneratorInfo(
          descriptor_->oneof_decl(i))->capitalized_name);
    printer->Indent();
    for (int j = 0; j < descriptor_->oneof_decl(i)->field_count(); j++) {
      const FieldDescriptor* field = descriptor_->oneof_decl(i)->field(j);
      printer->Print(
        "case $field_name$: {\n",
        "field_name",
        ToUpper(field->name()));
      printer->Indent();
      field_generators_.get(field).GenerateVisitCode(printer);
      printer->Print(
          "break;\n");
      printer->Outdent();
      printer->Print(
          "}\n");
    }
    printer->Print(
      "case $cap_oneof_name$_NOT_SET: {\n"
      "  visitor.visitOneofNotSet($oneof_name$Case_ != 0);\n"
      "  break;\n"
      "}\n",
      "cap_oneof_name",
      ToUpper(context_->GetOneofGeneratorInfo(
          descriptor_->oneof_decl(i))->name),
      "oneof_name",
      context_->GetOneofGeneratorInfo(
          descriptor_->oneof_decl(i))->name);
    printer->Outdent();
    printer->Print(
      "}\n");
  }

  printer->Print(
    "if (visitor == com.google.protobuf.GeneratedMessageLite.MergeFromVisitor\n"
    "    .INSTANCE) {\n");
  printer->Indent();
  for (int i = 0; i < descriptor_->oneof_decl_count(); ++i) {
    const OneofDescriptor* field = descriptor_->oneof_decl(i);
    printer->Print(
      "if (other.$oneof_name$Case_ != 0) {\n"
      "  $oneof_name$Case_ = other.$oneof_name$Case_;\n"
      "}\n",
      "oneof_name", context_->GetOneofGeneratorInfo(field)->name);
  }

  // Integers for bit fields.
  int totalBits = 0;
  for (int i = 0; i < descriptor_->field_count(); i++) {
    totalBits +=
        field_generators_.get(descriptor_->field(i)).GetNumBitsForMessage();
  }
  int totalInts = (totalBits + 31) / 32;

  for (int i = 0; i < totalInts; i++) {
    printer->Print("$bit_field_name$ |= other.$bit_field_name$;\n",
                   "bit_field_name", GetBitFieldName(i));
  }
  printer->Outdent();
  printer->Print(
    "}\n");


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

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

void ImmutableMessageLiteGenerator::GenerateDynamicMethodMergeFromStream(
    io::Printer* printer) {
  printer->Print(
      "com.google.protobuf.CodedInputStream input =\n"
      "    (com.google.protobuf.CodedInputStream) arg0;\n"
      "com.google.protobuf.ExtensionRegistryLite extensionRegistry =\n"
      "    (com.google.protobuf.ExtensionRegistryLite) arg1;\n"
      "if (extensionRegistry == null) {\n"
      "  throw new java.lang.NullPointerException();\n"
      "}\n");
  printer->Print(
      "try {\n");
  printer->Indent();
  printer->Print(
      "boolean done = false;\n"
      "while (!done) {\n");
  printer->Indent();

  printer->Print(
      "int tag = input.readTag();\n"
      "switch (tag) {\n");
  printer->Indent();

  printer->Print(
      "case 0:\n"  // zero signals EOF / limit reached
      "  done = true;\n"
      "  break;\n");

  std::unique_ptr<const FieldDescriptor* []> sorted_fields(
      SortFieldsByNumber(descriptor_));
  for (int i = 0; i < descriptor_->field_count(); i++) {
    const FieldDescriptor* field = sorted_fields[i];
    uint32 tag = WireFormatLite::MakeTag(
        field->number(), WireFormat::WireTypeForFieldType(field->type()));

    printer->Print("case $tag$: {\n", "tag",
                   StrCat(static_cast<int32>(tag)));
    printer->Indent();

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

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

    if (field->is_packable()) {
      // To make packed = true wire compatible, we generate parsing code from
      // a packed version of this field regardless of
      // field->options().packed().
      uint32 packed_tag = WireFormatLite::MakeTag(
          field->number(), WireFormatLite::WIRETYPE_LENGTH_DELIMITED);
      printer->Print("case $tag$: {\n", "tag",
                     StrCat(static_cast<int32>(packed_tag)));
      printer->Indent();

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

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

  if (descriptor_->extension_range_count() > 0) {
    if (descriptor_->options().message_set_wire_format()) {
      printer->Print(
          "default: {\n"
          "  if (!parseUnknownFieldAsMessageSet(\n"
          "      getDefaultInstanceForType(), input, extensionRegistry,\n"
          "      tag)) {\n"
          "    done = true;\n"  // it's an endgroup tag
          "  }\n"
          "  break;\n"
          "}\n");
    } else {
      printer->Print(
          "default: {\n"
          "  if (!parseUnknownField(getDefaultInstanceForType(),\n"
          "      input, extensionRegistry, tag)) {\n"
          "    done = true;\n"  // it's an endgroup tag
          "  }\n"
          "  break;\n"
          "}\n");
    }
  } else {
    printer->Print(
        "default: {\n"
        "  if (!parseUnknownField(tag, input)) {\n"
        "    done = true;\n"  // it's an endgroup tag
        "  }\n"
        "  break;\n"
        "}\n");
  }

  printer->Outdent();
  printer->Outdent();
  printer->Print(
      "  }\n"  // switch (tag)
      "}\n");  // while (!done)

  printer->Outdent();
  printer->Print(
      "} catch (com.google.protobuf.InvalidProtocolBufferException e) {\n"
      "  throw new RuntimeException(e.setUnfinishedMessage(this));\n"
      "} catch (java.io.IOException e) {\n"
      "  throw new RuntimeException(\n"
      "      new com.google.protobuf.InvalidProtocolBufferException(\n"
      "          e.getMessage()).setUnfinishedMessage(this));\n"
      "} finally {\n");
  printer->Indent();

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

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

void ImmutableMessageLiteGenerator::
GenerateExtensionRegistrationCode(io::Printer* printer) {
  for (int i = 0; i < descriptor_->extension_count(); i++) {
    ImmutableExtensionLiteGenerator(descriptor_->extension(i), context_)
      .GenerateRegistrationCode(printer);
  }

  for (int i = 0; i < descriptor_->nested_type_count(); i++) {
    ImmutableMessageLiteGenerator(descriptor_->nested_type(i), context_)
      .GenerateExtensionRegistrationCode(printer);
  }
}

// ===================================================================
void ImmutableMessageLiteGenerator::
GenerateConstructor(io::Printer* printer) {
  printer->Print(
      "private $classname$() {\n",
      "classname", descriptor_->name());
  printer->Indent();

  // Initialize all fields to default.
  GenerateInitializers(printer);

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

// ===================================================================
void ImmutableMessageLiteGenerator::GenerateParser(io::Printer* printer) {
  printer->Print(
      "private static volatile com.google.protobuf.Parser<$classname$> PARSER;\n"
      "\n"
      "public static com.google.protobuf.Parser<$classname$> parser() {\n"
      "  return DEFAULT_INSTANCE.getParserForType();\n"
      "}\n",
      "classname", descriptor_->name());
}

// ===================================================================
void ImmutableMessageLiteGenerator::GenerateInitializers(io::Printer* printer) {
  for (int i = 0; i < descriptor_->field_count(); i++) {
    if (!descriptor_->field(i)->containing_oneof()) {
      field_generators_.get(descriptor_->field(i))
          .GenerateInitializationCode(printer);
    }
  }
}

}  // namespace java
}  // namespace compiler
}  // namespace protobuf
}  // namespace google