lib/file_generator.dart - dart-protoc-plugin - Git at Google

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.

 part of protoc;

 final _dartIdentifier = new RegExp(r'^\w+$');
 final _formatter = new DartFormatter();
 final String _protobufImportPrefix = r'$pb';

 /// Generates the Dart output files for one .proto input file.
 ///
 /// Outputs include .pb.dart, pbenum.dart, and .pbjson.dart.
 class FileGenerator extends ProtobufContainer {
   /// Reads and the declared mixins in the file, keyed by name.
   ///
   /// Performs some basic validation on declared mixins, e.g. whether names
   /// are valid dart identifiers and whether there are cycles in the `parent`
   /// hierarchy.
   /// Does not check for existence of import files or classes.
   static Map<String, PbMixin> _getDeclaredMixins(FileDescriptorProto desc) {
     String mixinError(String error) =>
         'Option "mixins" in ${desc.name}: $error';

     if (!desc.hasOptions() ||
         !desc.options.hasExtension(Dart_options.imports)) {
       return <String, PbMixin>{};
     }
     var dartMixins = <String, DartMixin>{};
     Imports importedMixins = desc.options.getExtension(Dart_options.imports);
     for (DartMixin mixin in importedMixins.mixins) {
       if (dartMixins.containsKey(mixin.name)) {
         throw mixinError('Duplicate mixin name: "${mixin.name}"');
       }
       if (!mixin.name.startsWith(_dartIdentifier)) {
         throw mixinError(
             '"${mixin.name}" is not a valid dart class identifier');
       }
       if (mixin.hasParent() && !mixin.parent.startsWith(_dartIdentifier)) {
         throw mixinError('Mixin parent "${mixin.parent}" of "${mixin.name}" is '
             'not a valid dart class identifier');
       }
       dartMixins[mixin.name] = mixin;
     }

     // Detect cycles and unknown parents.
     for (var mixin in dartMixins.values) {
       if (!mixin.hasParent()) continue;
       var currentMixin = mixin;
       var parentChain = <String>[];
       while (currentMixin.hasParent()) {
         var parentName = currentMixin.parent;

         bool declaredMixin = dartMixins.containsKey(parentName);
         bool internalMixin = !declaredMixin && findMixin(parentName) != null;

         if (internalMixin) break; // No further validation of parent chain.

         if (!declaredMixin) {
           throw mixinError('Unknown mixin parent "${mixin.parent}" of '
               '"${currentMixin.name}"');
         }

         if (parentChain.contains(parentName)) {
           var cycle = parentChain.join('->') + '->$parentName';
           throw mixinError('Cycle in parent chain: $cycle');
         }
         parentChain.add(parentName);
         currentMixin = dartMixins[parentName];
       }
     }

     // Turn DartMixins into PbMixins.
     final pbMixins = <String, PbMixin>{};
     PbMixin resolveMixin(String name) {
       if (pbMixins.containsKey(name)) return pbMixins[name];
       if (dartMixins.containsKey(name)) {
         var dartMixin = dartMixins[name];
         var pbMixin = new PbMixin(dartMixin.name,
             importFrom: dartMixin.importFrom,
             parent: resolveMixin(dartMixin.parent));
         pbMixins[name] = pbMixin;
         return pbMixin;
       }
       return findMixin(name);
     }

     for (var mixin in dartMixins.values) {
       resolveMixin(mixin.name);
     }
     return pbMixins;
   }

   final FileDescriptorProto descriptor;
   final GenerationOptions options;

   // The relative path used to import the .proto file, as a URI.
   final Uri protoFileUri;

   final enumGenerators = <EnumGenerator>[];
   final messageGenerators = <MessageGenerator>[];
   final extensionGenerators = <ExtensionGenerator>[];
   final clientApiGenerators = <ClientApiGenerator>[];
   final serviceGenerators = <ServiceGenerator>[];
   final grpcGenerators = <GrpcServiceGenerator>[];

   /// True if cross-references have been resolved.
   bool _linked = false;

   FileGenerator(this.descriptor, this.options)
       : protoFileUri = new Uri.file(descriptor.name) {
     if (protoFileUri.isAbsolute) {
       // protoc should never generate an import with an absolute path.
       throw "FAILURE: Import with absolute path is not supported";
     }

     var declaredMixins = _getDeclaredMixins(descriptor);
     var defaultMixinName =
         descriptor.options?.getExtension(Dart_options.defaultMixin) ?? '';
     var defaultMixin =
         declaredMixins[defaultMixinName] ?? findMixin(defaultMixinName);
     if (defaultMixin == null && defaultMixinName.isNotEmpty) {
       throw ('Option default_mixin on file ${descriptor.name}: Unknown mixin '
           '$defaultMixinName');
     }

     // Load and register all enum and message types.
     for (EnumDescriptorProto enumType in descriptor.enumType) {
       enumGenerators.add(new EnumGenerator(enumType, this));
     }
     for (DescriptorProto messageType in descriptor.messageType) {
       messageGenerators.add(new MessageGenerator(
           messageType, this, declaredMixins, defaultMixin));
     }
     for (FieldDescriptorProto extension in descriptor.extension) {
       extensionGenerators.add(new ExtensionGenerator(extension, this));
     }
     for (ServiceDescriptorProto service in descriptor.service) {
       if (options.useGrpc) {
         grpcGenerators.add(new GrpcServiceGenerator(service, this));
       } else {
         var serviceGen = new ServiceGenerator(service, this);
         serviceGenerators.add(serviceGen);
         clientApiGenerators.add(new ClientApiGenerator(serviceGen));
       }
     }
   }

   /// Creates the fields in each message.
   /// Resolves field types and extension targets using the supplied context.
   void resolve(GenerationContext ctx) {
     if (_linked) throw new StateError("cross references already resolved");

     for (var m in messageGenerators) {
       m.resolve(ctx);
     }
     for (var x in extensionGenerators) {
       x.resolve(ctx);
     }

     _linked = true;
   }

   String get package => descriptor.package;
   String get classname => '';
   String get fullName => descriptor.package;
   FileGenerator get fileGen => this;

   /// Generates all the Dart files for this .proto file.
   List<CodeGeneratorResponse_File> generateFiles(OutputConfiguration config) {
     if (!_linked) throw new StateError("not linked");

     makeFile(String extension, String content) {
       Uri protoUrl = new Uri.file(descriptor.name);
       Uri dartUrl = config.outputPathFor(protoUrl, extension);
       return new CodeGeneratorResponse_File()
         ..name = dartUrl.path
         ..content = content;
     }

     final files = [
       makeFile(".pb.dart", generateMainFile(config)),
       makeFile(".pbenum.dart", generateEnumFile(config)),
       makeFile(".pbjson.dart", generateJsonFile(config)),
     ];
     if (options.useGrpc) {
       if (grpcGenerators.isNotEmpty) {
         files.add(makeFile(".pbgrpc.dart", generateGrpcFile(config)));
       }
     } else {
       files.add(makeFile(".pbserver.dart", generateServerFile(config)));
     }
     return files;
   }

   /// Returns the contents of the .pb.dart file for this .proto file.
   String generateMainFile(
       [OutputConfiguration config = const DefaultOutputConfiguration()]) {
     if (!_linked) throw new StateError("not linked");
     IndentingWriter out = new IndentingWriter();

     writeMainHeader(out, config);

     // Generate code.
     for (MessageGenerator m in messageGenerators) {
       m.generate(out);
     }

     // Generate code for extensions defined at top-level using a class
     // name derived from the file name.
     if (extensionGenerators.isNotEmpty) {
       // TODO(antonm): do not generate a class.
       String className = extensionClassName(descriptor);
       out.addBlock('class $className {', '}\n', () {
         for (ExtensionGenerator x in extensionGenerators) {
           x.generate(out);
         }
         out.println(
             'static void registerAllExtensions($_protobufImportPrefix.ExtensionRegistry '
             'registry) {');
         for (ExtensionGenerator x in extensionGenerators) {
           out.println('  registry.add(${x.name});');
         }
         out.println('}');
       });
     }

     for (ClientApiGenerator c in clientApiGenerators) {
       c.generate(out);
     }
     return out.toString();
   }

   /// Writes the header and imports for the .pb.dart file.
   void writeMainHeader(IndentingWriter out,
       [OutputConfiguration config = const DefaultOutputConfiguration()]) {
     _writeHeading(out);

     // We only add the dart:async import if there are generic client API
     // generators for services in the FileDescriptorProto.
     if (clientApiGenerators.isNotEmpty) {
       out.println("import 'dart:async';");
     }

     // Make sure any other symbols in dart:core don't cause name conflicts with
     // protobuf classes that have the same name.
     out.println("// ignore: UNUSED_SHOWN_NAME\n"
         "import 'dart:core' show int, bool, double, String, List, override;\n");

     if (_needsFixnumImport) {
       out.println("import 'package:fixnum/fixnum.dart';");
     }

     if (_needsProtobufImport) {
       out.println(
           "import 'package:protobuf/protobuf.dart' as $_protobufImportPrefix;");
       out.println();
     }

     var mixinImports = findMixinsToImport();
     var importNames = mixinImports.keys.toList();
     importNames.sort();
     for (var imp in importNames) {
       var symbols = mixinImports[imp];
       out.println("import '${imp}' show ${symbols.join(', ')};");
     }
     if (mixinImports.isNotEmpty) out.println();

     // Import the .pb.dart files we depend on.
     var imports = new Set<FileGenerator>.identity();
     var enumImports = new Set<FileGenerator>.identity();
     _findProtosToImport(imports, enumImports);

     for (var target in imports) {
       _writeImport(out, config, target, ".pb.dart");
     }
     if (imports.isNotEmpty) out.println();

     for (var target in enumImports) {
       _writeImport(out, config, target, ".pbenum.dart");
     }
     if (enumImports.isNotEmpty) out.println();

     // Export enums in main file for backward compatibility.
     if (enumCount > 0) {
       Uri resolvedImport =
           config.resolveImport(protoFileUri, protoFileUri, ".pbenum.dart");
       out.println("export '$resolvedImport';");
       out.println();
     }
   }

   bool get _needsFixnumImport {
     for (var m in messageGenerators) {
       if (m.needsFixnumImport) return true;
     }
     for (var x in extensionGenerators) {
       if (x.needsFixnumImport) return true;
     }
     return false;
   }

   bool get _needsProtobufImport =>
       messageGenerators.isNotEmpty ||
       extensionGenerators.isNotEmpty ||
       clientApiGenerators.isNotEmpty;

   /// Returns the generator for each .pb.dart file we need to import.
   void _findProtosToImport(
       Set<FileGenerator> imports, Set<FileGenerator> enumImports) {
     for (var m in messageGenerators) {
       m.addImportsTo(imports, enumImports);
     }
     for (var x in extensionGenerators) {
       x.addImportsTo(imports, enumImports);
     }
     // Add imports needed for client-side services.
     for (var x in serviceGenerators) {
       x.addImportsTo(imports);
     }
     // Don't need to import self. (But we may need to import the enums.)
     imports.remove(this);
   }

   /// Returns a map from import names to the Dart symbols to be imported.
   Map<String, List<String>> findMixinsToImport() {
     var mixins = new Set<PbMixin>();
     for (MessageGenerator m in messageGenerators) {
       m.addMixinsTo(mixins);
     }

     var imports = <String, List<String>>{};
     for (var m in mixins) {
       var imp = m.importFrom;
       List<String> symbols = imports[imp];
       if (symbols == null) {
         symbols = [];
         imports[imp] = symbols;
       }
       symbols.add(m.name);
     }

     for (var imp in imports.keys) {
       imports[imp].sort();
     }

     return imports;
   }

   /// Returns the contents of the .pbenum.dart file for this .proto file.
   String generateEnumFile(
       [OutputConfiguration config = const DefaultOutputConfiguration()]) {
     if (!_linked) throw new StateError("not linked");

     var out = new IndentingWriter();
     _writeHeading(out);

     if (enumCount > 0) {
       // Make sure any other symbols in dart:core don't cause name conflicts
       // with enums that have the same name.
       out.println("// ignore_for_file: UNDEFINED_SHOWN_NAME,UNUSED_SHOWN_NAME\n"
           "import 'dart:core' show int, dynamic, String, List, Map;");
       out.println(
           "import 'package:protobuf/protobuf.dart' as $_protobufImportPrefix;");
       out.println();
     }

     for (EnumGenerator e in enumGenerators) {
       e.generate(out);
     }

     for (MessageGenerator m in messageGenerators) {
       m.generateEnums(out);
     }

     return out.toString();
   }

   /// Returns the number of enum types generated in the .pbenum.dart file.
   int get enumCount {
     var count = enumGenerators.length;
     for (MessageGenerator m in messageGenerators) {
       count += m.enumCount;
     }
     return count;
   }

   /// Returns the contents of the .pbserver.dart file for this .proto file.
   String generateServerFile(
       [OutputConfiguration config = const DefaultOutputConfiguration()]) {
     if (!_linked) throw new StateError("not linked");
     var out = new IndentingWriter();
     _writeHeading(out);

     if (serviceGenerators.isNotEmpty) {
       out.println('''
 import 'dart:async';

 import 'package:protobuf/protobuf.dart';
 ''');
     }

     // Import .pb.dart files needed for requests and responses.
     var imports = new Set<FileGenerator>();
     for (var x in serviceGenerators) {
       x.addImportsTo(imports);
     }
     for (var target in imports) {
       _writeImport(out, config, target, ".pb.dart");
     }

     // Import .pbjson.dart file needed for $json and $messageJson.
     if (serviceGenerators.isNotEmpty) {
       _writeImport(out, config, this, ".pbjson.dart");
       out.println();
     }

     Uri resolvedImport =
         config.resolveImport(protoFileUri, protoFileUri, ".pb.dart");
     out.println("export '$resolvedImport';");
     out.println();

     for (ServiceGenerator s in serviceGenerators) {
       s.generate(out);
     }

     return out.toString();
   }

   /// Returns the contents of the .pbgrpc.dart file for this .proto file.
   String generateGrpcFile(
       [OutputConfiguration config = const DefaultOutputConfiguration()]) {
     if (!_linked) throw new StateError("not linked");
     var out = new IndentingWriter();
     _writeHeading(out);

     out.println('''
 import 'dart:async';

 import 'package:grpc/grpc.dart';
 ''');

     // Import .pb.dart files needed for requests and responses.
     var imports = new Set<FileGenerator>();
     for (var generator in grpcGenerators) {
       generator.addImportsTo(imports);
     }
     for (var target in imports) {
       _writeImport(out, config, target, ".pb.dart");
     }

     var resolvedImport =
         config.resolveImport(protoFileUri, protoFileUri, ".pb.dart");
     out.println("export '$resolvedImport';");
     out.println();

     for (var generator in grpcGenerators) {
       generator.generate(out);
     }

     return _formatter.format(out.toString());
   }

   /// Returns the contents of the .pbjson.dart file for this .proto file.
   String generateJsonFile(
       [OutputConfiguration config = const DefaultOutputConfiguration()]) {
     if (!_linked) throw new StateError("not linked");
     var out = new IndentingWriter();
     _writeHeading(out);

     // Import the .pbjson.dart files we depend on.
     var imports = _findJsonProtosToImport();
     for (var target in imports) {
       _writeImport(out, config, target, ".pbjson.dart");
     }
     if (imports.isNotEmpty) out.println();

     for (var e in enumGenerators) {
       e.generateConstants(out);
     }
     for (MessageGenerator m in messageGenerators) {
       m.generateConstants(out);
     }
     for (ServiceGenerator s in serviceGenerators) {
       s.generateConstants(out);
     }

     return out.toString();
   }

   /// Returns the generator for each .pbjson.dart file the generated
   /// .pbjson.dart needs to import.
   Set<FileGenerator> _findJsonProtosToImport() {
     var imports = new Set<FileGenerator>.identity();
     for (var m in messageGenerators) {
       m.addConstantImportsTo(imports);
     }
     for (var x in extensionGenerators) {
       x.addConstantImportsTo(imports);
     }
     for (var x in serviceGenerators) {
       x.addConstantImportsTo(imports);
     }
     imports.remove(this); // Don't need to import self.
     return imports;
   }

   /// Writes the header at the top of the dart file.
   void _writeHeading(IndentingWriter out) {
     out.println('''
 ///
 //  Generated code. Do not modify.
 //  source: ${descriptor.name}
 ///
 // ignore_for_file: non_constant_identifier_names,library_prefixes,unused_import
 ''');
   }

   /// Writes an import of a .dart file corresponding to a .proto file.
   /// (Possibly the same .proto file.)
   void _writeImport(IndentingWriter out, OutputConfiguration config,
       FileGenerator target, String extension) {
     Uri resolvedImport =
         config.resolveImport(target.protoFileUri, protoFileUri, extension);
     out.print("import '$resolvedImport'");
     if (protoFileUri != target.protoFileUri) {
       out.print(' as ${target.fileImportPrefix}');
     }
     out.println(';');
   }
 }
	// Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file
	// for details. All rights reserved. Use of this source code is governed by a
	// BSD-style license that can be found in the LICENSE file.

	part of protoc;

	final _dartIdentifier = new RegExp(r'^\w+$');
	final _formatter = new DartFormatter();
	final String _protobufImportPrefix = r'$pb';

	/// Generates the Dart output files for one .proto input file.
	///
	/// Outputs include .pb.dart, pbenum.dart, and .pbjson.dart.
	class FileGenerator extends ProtobufContainer {
	/// Reads and the declared mixins in the file, keyed by name.
	///
	/// Performs some basic validation on declared mixins, e.g. whether names
	/// are valid dart identifiers and whether there are cycles in the `parent`
	/// hierarchy.
	/// Does not check for existence of import files or classes.
	static Map<String, PbMixin> _getDeclaredMixins(FileDescriptorProto desc) {
	String mixinError(String error) =>
	'Option "mixins" in ${desc.name}: $error';

	if (!desc.hasOptions() \|\|
	!desc.options.hasExtension(Dart_options.imports)) {
	return <String, PbMixin>{};
	}
	var dartMixins = <String, DartMixin>{};
	Imports importedMixins = desc.options.getExtension(Dart_options.imports);
	for (DartMixin mixin in importedMixins.mixins) {
	if (dartMixins.containsKey(mixin.name)) {
	throw mixinError('Duplicate mixin name: "${mixin.name}"');
	}
	if (!mixin.name.startsWith(_dartIdentifier)) {
	throw mixinError(
	'"${mixin.name}" is not a valid dart class identifier');
	}
	if (mixin.hasParent() && !mixin.parent.startsWith(_dartIdentifier)) {
	throw mixinError('Mixin parent "${mixin.parent}" of "${mixin.name}" is '
	'not a valid dart class identifier');
	}
	dartMixins[mixin.name] = mixin;
	}

	// Detect cycles and unknown parents.
	for (var mixin in dartMixins.values) {
	if (!mixin.hasParent()) continue;
	var currentMixin = mixin;
	var parentChain = <String>[];
	while (currentMixin.hasParent()) {
	var parentName = currentMixin.parent;

	bool declaredMixin = dartMixins.containsKey(parentName);
	bool internalMixin = !declaredMixin && findMixin(parentName) != null;

	if (internalMixin) break; // No further validation of parent chain.

	if (!declaredMixin) {
	throw mixinError('Unknown mixin parent "${mixin.parent}" of '
	'"${currentMixin.name}"');
	}

	if (parentChain.contains(parentName)) {
	var cycle = parentChain.join('->') + '->$parentName';
	throw mixinError('Cycle in parent chain: $cycle');
	}
	parentChain.add(parentName);
	currentMixin = dartMixins[parentName];
	}
	}

	// Turn DartMixins into PbMixins.
	final pbMixins = <String, PbMixin>{};
	PbMixin resolveMixin(String name) {
	if (pbMixins.containsKey(name)) return pbMixins[name];
	if (dartMixins.containsKey(name)) {
	var dartMixin = dartMixins[name];
	var pbMixin = new PbMixin(dartMixin.name,
	importFrom: dartMixin.importFrom,
	parent: resolveMixin(dartMixin.parent));
	pbMixins[name] = pbMixin;
	return pbMixin;
	}
	return findMixin(name);
	}

	for (var mixin in dartMixins.values) {
	resolveMixin(mixin.name);
	}
	return pbMixins;
	}

	final FileDescriptorProto descriptor;
	final GenerationOptions options;

	// The relative path used to import the .proto file, as a URI.
	final Uri protoFileUri;

	final enumGenerators = <EnumGenerator>[];
	final messageGenerators = <MessageGenerator>[];
	final extensionGenerators = <ExtensionGenerator>[];
	final clientApiGenerators = <ClientApiGenerator>[];
	final serviceGenerators = <ServiceGenerator>[];
	final grpcGenerators = <GrpcServiceGenerator>[];

	/// True if cross-references have been resolved.
	bool _linked = false;

	FileGenerator(this.descriptor, this.options)
	: protoFileUri = new Uri.file(descriptor.name) {
	if (protoFileUri.isAbsolute) {
	// protoc should never generate an import with an absolute path.
	throw "FAILURE: Import with absolute path is not supported";
	}

	var declaredMixins = _getDeclaredMixins(descriptor);
	var defaultMixinName =
	descriptor.options?.getExtension(Dart_options.defaultMixin) ?? '';
	var defaultMixin =
	declaredMixins[defaultMixinName] ?? findMixin(defaultMixinName);
	if (defaultMixin == null && defaultMixinName.isNotEmpty) {
	throw ('Option default_mixin on file ${descriptor.name}: Unknown mixin '
	'$defaultMixinName');
	}

	// Load and register all enum and message types.
	for (EnumDescriptorProto enumType in descriptor.enumType) {
	enumGenerators.add(new EnumGenerator(enumType, this));
	}
	for (DescriptorProto messageType in descriptor.messageType) {
	messageGenerators.add(new MessageGenerator(
	messageType, this, declaredMixins, defaultMixin));
	}
	for (FieldDescriptorProto extension in descriptor.extension) {
	extensionGenerators.add(new ExtensionGenerator(extension, this));
	}
	for (ServiceDescriptorProto service in descriptor.service) {
	if (options.useGrpc) {
	grpcGenerators.add(new GrpcServiceGenerator(service, this));
	} else {
	var serviceGen = new ServiceGenerator(service, this);
	serviceGenerators.add(serviceGen);
	clientApiGenerators.add(new ClientApiGenerator(serviceGen));
	}
	}
	}

	/// Creates the fields in each message.
	/// Resolves field types and extension targets using the supplied context.
	void resolve(GenerationContext ctx) {
	if (_linked) throw new StateError("cross references already resolved");

	for (var m in messageGenerators) {
	m.resolve(ctx);
	}
	for (var x in extensionGenerators) {
	x.resolve(ctx);
	}

	_linked = true;
	}

	String get package => descriptor.package;
	String get classname => '';
	String get fullName => descriptor.package;
	FileGenerator get fileGen => this;

	/// Generates all the Dart files for this .proto file.
	List<CodeGeneratorResponse_File> generateFiles(OutputConfiguration config) {
	if (!_linked) throw new StateError("not linked");

	makeFile(String extension, String content) {
	Uri protoUrl = new Uri.file(descriptor.name);
	Uri dartUrl = config.outputPathFor(protoUrl, extension);
	return new CodeGeneratorResponse_File()
	..name = dartUrl.path
	..content = content;
	}

	final files = [
	makeFile(".pb.dart", generateMainFile(config)),
	makeFile(".pbenum.dart", generateEnumFile(config)),
	makeFile(".pbjson.dart", generateJsonFile(config)),
	];
	if (options.useGrpc) {
	if (grpcGenerators.isNotEmpty) {
	files.add(makeFile(".pbgrpc.dart", generateGrpcFile(config)));
	}
	} else {
	files.add(makeFile(".pbserver.dart", generateServerFile(config)));
	}
	return files;
	}

	/// Returns the contents of the .pb.dart file for this .proto file.
	String generateMainFile(
	[OutputConfiguration config = const DefaultOutputConfiguration()]) {
	if (!_linked) throw new StateError("not linked");
	IndentingWriter out = new IndentingWriter();

	writeMainHeader(out, config);

	// Generate code.
	for (MessageGenerator m in messageGenerators) {
	m.generate(out);
	}

	// Generate code for extensions defined at top-level using a class
	// name derived from the file name.
	if (extensionGenerators.isNotEmpty) {
	// TODO(antonm): do not generate a class.
	String className = extensionClassName(descriptor);
	out.addBlock('class $className {', '}\n', () {
	for (ExtensionGenerator x in extensionGenerators) {
	x.generate(out);
	}
	out.println(
	'static void registerAllExtensions($_protobufImportPrefix.ExtensionRegistry '
	'registry) {');
	for (ExtensionGenerator x in extensionGenerators) {
	out.println(' registry.add(${x.name});');
	}
	out.println('}');
	});
	}

	for (ClientApiGenerator c in clientApiGenerators) {
	c.generate(out);
	}
	return out.toString();
	}

	/// Writes the header and imports for the .pb.dart file.
	void writeMainHeader(IndentingWriter out,
	[OutputConfiguration config = const DefaultOutputConfiguration()]) {
	_writeHeading(out);

	// We only add the dart:async import if there are generic client API
	// generators for services in the FileDescriptorProto.
	if (clientApiGenerators.isNotEmpty) {
	out.println("import 'dart:async';");
	}

	// Make sure any other symbols in dart:core don't cause name conflicts with
	// protobuf classes that have the same name.
	out.println("// ignore: UNUSED_SHOWN_NAME\n"
	"import 'dart:core' show int, bool, double, String, List, override;\n");

	if (_needsFixnumImport) {
	out.println("import 'package:fixnum/fixnum.dart';");
	}

	if (_needsProtobufImport) {
	out.println(
	"import 'package:protobuf/protobuf.dart' as $_protobufImportPrefix;");
	out.println();
	}

	var mixinImports = findMixinsToImport();
	var importNames = mixinImports.keys.toList();
	importNames.sort();
	for (var imp in importNames) {
	var symbols = mixinImports[imp];
	out.println("import '${imp}' show ${symbols.join(', ')};");
	}
	if (mixinImports.isNotEmpty) out.println();

	// Import the .pb.dart files we depend on.
	var imports = new Set<FileGenerator>.identity();
	var enumImports = new Set<FileGenerator>.identity();
	_findProtosToImport(imports, enumImports);

	for (var target in imports) {
	_writeImport(out, config, target, ".pb.dart");
	}
	if (imports.isNotEmpty) out.println();

	for (var target in enumImports) {
	_writeImport(out, config, target, ".pbenum.dart");
	}
	if (enumImports.isNotEmpty) out.println();

	// Export enums in main file for backward compatibility.
	if (enumCount > 0) {
	Uri resolvedImport =
	config.resolveImport(protoFileUri, protoFileUri, ".pbenum.dart");
	out.println("export '$resolvedImport';");
	out.println();
	}
	}

	bool get _needsFixnumImport {
	for (var m in messageGenerators) {
	if (m.needsFixnumImport) return true;
	}
	for (var x in extensionGenerators) {
	if (x.needsFixnumImport) return true;
	}
	return false;
	}

	bool get _needsProtobufImport =>
	messageGenerators.isNotEmpty \|\|
	extensionGenerators.isNotEmpty \|\|
	clientApiGenerators.isNotEmpty;

	/// Returns the generator for each .pb.dart file we need to import.
	void _findProtosToImport(
	Set<FileGenerator> imports, Set<FileGenerator> enumImports) {
	for (var m in messageGenerators) {
	m.addImportsTo(imports, enumImports);
	}
	for (var x in extensionGenerators) {
	x.addImportsTo(imports, enumImports);
	}
	// Add imports needed for client-side services.
	for (var x in serviceGenerators) {
	x.addImportsTo(imports);
	}
	// Don't need to import self. (But we may need to import the enums.)
	imports.remove(this);
	}

	/// Returns a map from import names to the Dart symbols to be imported.
	Map<String, List<String>> findMixinsToImport() {
	var mixins = new Set<PbMixin>();
	for (MessageGenerator m in messageGenerators) {
	m.addMixinsTo(mixins);
	}

	var imports = <String, List<String>>{};
	for (var m in mixins) {
	var imp = m.importFrom;
	List<String> symbols = imports[imp];
	if (symbols == null) {
	symbols = [];
	imports[imp] = symbols;
	}
	symbols.add(m.name);
	}

	for (var imp in imports.keys) {
	imports[imp].sort();
	}

	return imports;
	}

	/// Returns the contents of the .pbenum.dart file for this .proto file.
	String generateEnumFile(
	[OutputConfiguration config = const DefaultOutputConfiguration()]) {
	if (!_linked) throw new StateError("not linked");

	var out = new IndentingWriter();
	_writeHeading(out);

	if (enumCount > 0) {
	// Make sure any other symbols in dart:core don't cause name conflicts
	// with enums that have the same name.
	out.println("// ignore_for_file: UNDEFINED_SHOWN_NAME,UNUSED_SHOWN_NAME\n"
	"import 'dart:core' show int, dynamic, String, List, Map;");
	out.println(
	"import 'package:protobuf/protobuf.dart' as $_protobufImportPrefix;");
	out.println();
	}

	for (EnumGenerator e in enumGenerators) {
	e.generate(out);
	}

	for (MessageGenerator m in messageGenerators) {
	m.generateEnums(out);
	}

	return out.toString();
	}

	/// Returns the number of enum types generated in the .pbenum.dart file.
	int get enumCount {
	var count = enumGenerators.length;
	for (MessageGenerator m in messageGenerators) {
	count += m.enumCount;
	}
	return count;
	}

	/// Returns the contents of the .pbserver.dart file for this .proto file.
	String generateServerFile(
	[OutputConfiguration config = const DefaultOutputConfiguration()]) {
	if (!_linked) throw new StateError("not linked");
	var out = new IndentingWriter();
	_writeHeading(out);

	if (serviceGenerators.isNotEmpty) {
	out.println('''
	import 'dart:async';

	import 'package:protobuf/protobuf.dart';
	''');
	}

	// Import .pb.dart files needed for requests and responses.
	var imports = new Set<FileGenerator>();
	for (var x in serviceGenerators) {
	x.addImportsTo(imports);
	}
	for (var target in imports) {
	_writeImport(out, config, target, ".pb.dart");
	}

	// Import .pbjson.dart file needed for $json and $messageJson.
	if (serviceGenerators.isNotEmpty) {
	_writeImport(out, config, this, ".pbjson.dart");
	out.println();
	}

	Uri resolvedImport =
	config.resolveImport(protoFileUri, protoFileUri, ".pb.dart");
	out.println("export '$resolvedImport';");
	out.println();

	for (ServiceGenerator s in serviceGenerators) {
	s.generate(out);
	}

	return out.toString();
	}

	/// Returns the contents of the .pbgrpc.dart file for this .proto file.
	String generateGrpcFile(
	[OutputConfiguration config = const DefaultOutputConfiguration()]) {
	if (!_linked) throw new StateError("not linked");
	var out = new IndentingWriter();
	_writeHeading(out);

	out.println('''
	import 'dart:async';

	import 'package:grpc/grpc.dart';
	''');

	// Import .pb.dart files needed for requests and responses.
	var imports = new Set<FileGenerator>();
	for (var generator in grpcGenerators) {
	generator.addImportsTo(imports);
	}
	for (var target in imports) {
	_writeImport(out, config, target, ".pb.dart");
	}

	var resolvedImport =
	config.resolveImport(protoFileUri, protoFileUri, ".pb.dart");
	out.println("export '$resolvedImport';");
	out.println();

	for (var generator in grpcGenerators) {
	generator.generate(out);
	}

	return _formatter.format(out.toString());
	}

	/// Returns the contents of the .pbjson.dart file for this .proto file.
	String generateJsonFile(
	[OutputConfiguration config = const DefaultOutputConfiguration()]) {
	if (!_linked) throw new StateError("not linked");
	var out = new IndentingWriter();
	_writeHeading(out);

	// Import the .pbjson.dart files we depend on.
	var imports = _findJsonProtosToImport();
	for (var target in imports) {
	_writeImport(out, config, target, ".pbjson.dart");
	}
	if (imports.isNotEmpty) out.println();

	for (var e in enumGenerators) {
	e.generateConstants(out);
	}
	for (MessageGenerator m in messageGenerators) {
	m.generateConstants(out);
	}
	for (ServiceGenerator s in serviceGenerators) {
	s.generateConstants(out);
	}

	return out.toString();
	}

	/// Returns the generator for each .pbjson.dart file the generated
	/// .pbjson.dart needs to import.
	Set<FileGenerator> _findJsonProtosToImport() {
	var imports = new Set<FileGenerator>.identity();
	for (var m in messageGenerators) {
	m.addConstantImportsTo(imports);
	}
	for (var x in extensionGenerators) {
	x.addConstantImportsTo(imports);
	}
	for (var x in serviceGenerators) {
	x.addConstantImportsTo(imports);
	}
	imports.remove(this); // Don't need to import self.
	return imports;
	}

	/// Writes the header at the top of the dart file.
	void _writeHeading(IndentingWriter out) {
	out.println('''
	///
	// Generated code. Do not modify.
	// source: ${descriptor.name}
	///
	// ignore_for_file: non_constant_identifier_names,library_prefixes,unused_import
	''');
	}

	/// Writes an import of a .dart file corresponding to a .proto file.
	/// (Possibly the same .proto file.)
	void _writeImport(IndentingWriter out, OutputConfiguration config,
	FileGenerator target, String extension) {
	Uri resolvedImport =
	config.resolveImport(target.protoFileUri, protoFileUri, extension);
	out.print("import '$resolvedImport'");
	if (protoFileUri != target.protoFileUri) {
	out.print(' as ${target.fileImportPrefix}');
	}
	out.println(';');
	}
	}