protoc_plugin/lib/src/file_generator.dart - external/github.com/dart-lang/protobuf - 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.

 // @dart=2.11

 part of '../protoc.dart';

 final _dartIdentifier = RegExp(r'^\w+$');
 final _formatter = DartFormatter();
 const String _convertImportPrefix = r'$convert';

 const String _fixnumImportPrefix = r'$fixnum';
 const String _typedDataImportPrefix = r'$typed_data';
 const String _protobufImport =
     "import 'package:protobuf/protobuf.dart' as $protobufImportPrefix;";
 const String _asyncImport = "import 'dart:async' as $asyncImportPrefix;";
 const String _coreImport = "import 'dart:core' as $coreImportPrefix;";
 const String _typedDataImport =
     "import 'dart:typed_data' as $_typedDataImportPrefix;";
 const String _convertImport = "import 'dart:convert' as $_convertImportPrefix;";

 const String _grpcImport =
     "import 'package:grpc/service_api.dart' as $grpcImportPrefix;";

 /// Generates code that will evaluate to the empty string if
 /// `const bool.fromEnvironment(envName)` is `true` and evaluate to [value]
 /// otherwise.
 String configurationDependent(String envName, String value) {
   return 'const $coreImportPrefix.bool.fromEnvironment(${quoted(envName)})'
       ' ? \'\' '
       ': $value';
 }

 /// 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>{};
     final importedMixins =
         desc.options.getExtension(Dart_options.imports) as Imports;
     for (var 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;

         var declaredMixin = dartMixins.containsKey(parentName);
         var 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 = 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>[];

   /// Used to avoid collisions after names have been mangled to match the Dart
   /// style.
   final Set<String> usedTopLevelNames = <String>{}
     ..addAll(forbiddenTopLevelNames);

   /// Used to avoid collisions in the service file after names have been mangled
   /// to match the dart style.
   final Set<String> usedTopLevelServiceNames = <String>{}
     ..addAll(forbiddenTopLevelNames);

   final Set<String> usedExtensionNames = <String>{}
     ..addAll(forbiddenExtensionNames);

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

   FileGenerator(this.descriptor, this.options)
       : protoFileUri = 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) as String ??
             '';
     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 (var i = 0; i < descriptor.enumType.length; i++) {
       enumGenerators.add(EnumGenerator.topLevel(
           descriptor.enumType[i], this, usedTopLevelNames, i));
     }
     for (var i = 0; i < descriptor.messageType.length; i++) {
       messageGenerators.add(MessageGenerator.topLevel(descriptor.messageType[i],
           this, declaredMixins, defaultMixin, usedTopLevelNames, i));
     }
     for (var i = 0; i < descriptor.extension.length; i++) {
       extensionGenerators.add(ExtensionGenerator.topLevel(
           descriptor.extension[i], this, usedExtensionNames, i));
     }
     for (var service in descriptor.service) {
       if (options.useGrpc) {
         grpcGenerators.add(GrpcServiceGenerator(service, this));
       } else {
         var serviceGen =
             ServiceGenerator(service, this, usedTopLevelServiceNames);
         serviceGenerators.add(serviceGen);
         clientApiGenerators
             .add(ClientApiGenerator(serviceGen, usedTopLevelNames));
       }
     }
   }

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

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

     _linked = true;
   }

   @override
   String get package => descriptor.package;
   @override
   String get classname => '';
   @override
   String get fullName => descriptor.package;
   @override
   FileGenerator get fileGen => this;
   @override
   ProtobufContainer get parent => null;
   @override
   List<int> get fieldPath => [];

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

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

     var mainWriter = generateMainFile(config);
     var enumWriter = generateEnumFile(config);

     final files = [
       makeFile('.pb.dart', mainWriter.toString()),
       makeFile('.pbenum.dart', enumWriter.toString()),
       makeFile('.pbjson.dart', generateJsonFile(config)),
     ];

     if (options.generateMetadata) {
       files.addAll([
         makeFile('.pb.dart.meta',
             mainWriter.sourceLocationInfo.writeToJson().toString()),
         makeFile('.pbenum.dart.meta',
             enumWriter.sourceLocationInfo.writeToJson().toString())
       ]);
     }
     if (options.useGrpc) {
       if (grpcGenerators.isNotEmpty) {
         files.add(makeFile('.pbgrpc.dart', generateGrpcFile(config)));
       }
     } else {
       files.add(makeFile('.pbserver.dart', generateServerFile(config)));
     }
     return files;
   }

   /// Creates an IndentingWriter with metadata generation enabled or disabled.
   IndentingWriter makeWriter() => IndentingWriter(
       filename: options.generateMetadata ? descriptor.name : null);

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

     writeMainHeader(out, config);

     // Generate code.
     for (var 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.
       var className = extensionClassName(descriptor, usedTopLevelNames);
       out.addBlock('class $className {', '}\n', () {
         for (var x in extensionGenerators) {
           x.generate(out);
         }
         out.println(
             'static void registerAllExtensions($protobufImportPrefix.ExtensionRegistry '
             'registry) {');
         for (var x in extensionGenerators) {
           out.println('  registry.add(${x.name});');
         }
         out.println('}');
       });
     }

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

   /// 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(_asyncImport);
     }

     out.println(_coreImport);
     out.println();

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

     if (_needsProtobufImport) {
       out.println(_protobufImport);
       out.println();
     }

     final mixinImports = findMixinImports();
     for (var libraryUri in mixinImports) {
       out.println("import '$libraryUri' as $mixinImportPrefix;");
     }
     if (mixinImports.isNotEmpty) out.println();

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

     for (var publicDependency in descriptor.publicDependency) {
       _writeExport(out, config,
           Uri.file(descriptor.dependency[publicDependency]), '.pb.dart');
     }

     // Export enums in main file for backward compatibility.
     if (enumCount > 0) {
       var 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 sorted list of imports needed to support all mixins.
   List<String> findMixinImports() {
     var mixins = <PbMixin>{};
     for (var m in messageGenerators) {
       m.addMixinsTo(mixins);
     }

     return mixins
         .map((mixin) => mixin.importFrom)
         .toSet()
         .toList(growable: false)
       ..sort();
   }

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

     var out = makeWriter();
     _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');
       out.println(_coreImport);
       out.println(_protobufImport);
       out.println();
     }

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

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

     return out;
   }

   /// Returns the number of enum types generated in the .pbenum.dart file.
   int get enumCount {
     var count = enumGenerators.length;
     for (var 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 StateError('not linked');
     var out = makeWriter();
     _writeHeading(out,
         extraIgnores: {'deprecated_member_use_from_same_package'});

     if (serviceGenerators.isNotEmpty) {
       out.println(_asyncImport);
       out.println();
       out.println(_protobufImport);
       out.println();
       out.println(_coreImport);
     }

     // Import .pb.dart files needed for requests and responses.
     var imports = <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();
     }

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

     for (var 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 StateError('not linked');
     var out = makeWriter();
     _writeHeading(out);

     out.println(_asyncImport);
     out.println();
     out.println(_coreImport);
     out.println();
     out.println(_grpcImport);

     // Import .pb.dart files needed for requests and responses.
     var imports = <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());
   }

   void writeBinaryDescriptor(IndentingWriter out, String identifierName,
       String name, GeneratedMessage descriptor) {
     var descriptorText = base64Encode(descriptor.writeToBuffer());
     out.println('/// Descriptor for `$name`. Decode as a '
         '`${descriptor.info_.qualifiedMessageName}`.');
     out.println('final $_typedDataImportPrefix.Uint8List '
         '$identifierName = '
         '$_convertImportPrefix.base64Decode(\'$descriptorText\');');
   }

   /// Returns the contents of the .pbjson.dart file for this .proto file.
   String generateJsonFile(
       [OutputConfiguration config = const DefaultOutputConfiguration()]) {
     if (!_linked) throw StateError('not linked');
     var out = makeWriter();
     _writeHeading(out,
         extraIgnores: {'deprecated_member_use_from_same_package'});

     out.println(_coreImport);
     out.println(_convertImport);
     out.println(_typedDataImport);
     // 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);
       writeBinaryDescriptor(
           out, e.binaryDescriptorName, e._descriptor.name, e._descriptor);
     }
     for (var m in messageGenerators) {
       m.generateConstants(out);
       writeBinaryDescriptor(
           out, m.binaryDescriptorName, m._descriptor.name, m._descriptor);
     }
     for (var s in serviceGenerators) {
       s.generateConstants(out);
       writeBinaryDescriptor(
           out, s.binaryDescriptorName, s._descriptor.name, s._descriptor);
     }

     return out.toString();
   }

   /// Returns the generator for each .pbjson.dart file the generated
   /// .pbjson.dart needs to import.
   Set<FileGenerator> _findJsonProtosToImport() {
     var imports = 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, {
     Set<String> extraIgnores = const <String>{},
   }) {
     final ignores = ({
       ..._ignores,
       ...extraIgnores,
     }).toList()
       ..sort();

     out.println('''
 ///
 //  Generated code. Do not modify.
 //  source: ${descriptor.name}
 //
 // @dart = 2.12
 // ignore_for_file: ${ignores.join(',')}
 ''');
   }

   /// 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) {
     var resolvedImport =
         config.resolveImport(target.protoFileUri, protoFileUri, extension);
     out.print("import '$resolvedImport'");

     // .pb.dart files should always be prefixed--the protoFileUri check
     // will evaluate to true not just for the main .pb.dart file based off
     // the proto file, but also for the .pbserver.dart, .pbgrpc.dart files.
     if ((extension == '.pb.dart') || protoFileUri != target.protoFileUri) {
       out.print(' as ${target.fileImportPrefix}');
     }
     out.println(';');
   }

   /// Writes an export of a pb.dart file corresponding to a .proto file.
   /// (Possibly the same .proto file.)
   void _writeExport(IndentingWriter out, OutputConfiguration config, Uri target,
       String extension) {
     var resolvedImport = config.resolveImport(target, protoFileUri, extension);
     out.println("export '$resolvedImport';");
   }
 }

 const _ignores = {
   'annotate_overrides',
   'directives_ordering',
   'camel_case_types',
   'constant_identifier_names',
   'library_prefixes',
   'non_constant_identifier_names',
   'prefer_final_fields',
   'return_of_invalid_type',
   'unnecessary_const',
   'unnecessary_import',
   'unnecessary_this',
   'unused_import',
   'unused_shown_name',
 };
	// 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.

	// @dart=2.11

	part of '../protoc.dart';

	final _dartIdentifier = RegExp(r'^\w+$');
	final _formatter = DartFormatter();
	const String _convertImportPrefix = r'$convert';

	const String _fixnumImportPrefix = r'$fixnum';
	const String _typedDataImportPrefix = r'$typed_data';
	const String _protobufImport =
	"import 'package:protobuf/protobuf.dart' as $protobufImportPrefix;";
	const String _asyncImport = "import 'dart:async' as $asyncImportPrefix;";
	const String _coreImport = "import 'dart:core' as $coreImportPrefix;";
	const String _typedDataImport =
	"import 'dart:typed_data' as $_typedDataImportPrefix;";
	const String _convertImport = "import 'dart:convert' as $_convertImportPrefix;";

	const String _grpcImport =
	"import 'package:grpc/service_api.dart' as $grpcImportPrefix;";

	/// Generates code that will evaluate to the empty string if
	/// `const bool.fromEnvironment(envName)` is `true` and evaluate to [value]
	/// otherwise.
	String configurationDependent(String envName, String value) {
	return 'const $coreImportPrefix.bool.fromEnvironment(${quoted(envName)})'
	' ? \'\' '
	': $value';
	}

	/// 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>{};
	final importedMixins =
	desc.options.getExtension(Dart_options.imports) as Imports;
	for (var 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;

	var declaredMixin = dartMixins.containsKey(parentName);
	var 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 = 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>[];

	/// Used to avoid collisions after names have been mangled to match the Dart
	/// style.
	final Set<String> usedTopLevelNames = <String>{}
	..addAll(forbiddenTopLevelNames);

	/// Used to avoid collisions in the service file after names have been mangled
	/// to match the dart style.
	final Set<String> usedTopLevelServiceNames = <String>{}
	..addAll(forbiddenTopLevelNames);

	final Set<String> usedExtensionNames = <String>{}
	..addAll(forbiddenExtensionNames);

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

	FileGenerator(this.descriptor, this.options)
	: protoFileUri = 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) as String ??
	'';
	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 (var i = 0; i < descriptor.enumType.length; i++) {
	enumGenerators.add(EnumGenerator.topLevel(
	descriptor.enumType[i], this, usedTopLevelNames, i));
	}
	for (var i = 0; i < descriptor.messageType.length; i++) {
	messageGenerators.add(MessageGenerator.topLevel(descriptor.messageType[i],
	this, declaredMixins, defaultMixin, usedTopLevelNames, i));
	}
	for (var i = 0; i < descriptor.extension.length; i++) {
	extensionGenerators.add(ExtensionGenerator.topLevel(
	descriptor.extension[i], this, usedExtensionNames, i));
	}
	for (var service in descriptor.service) {
	if (options.useGrpc) {
	grpcGenerators.add(GrpcServiceGenerator(service, this));
	} else {
	var serviceGen =
	ServiceGenerator(service, this, usedTopLevelServiceNames);
	serviceGenerators.add(serviceGen);
	clientApiGenerators
	.add(ClientApiGenerator(serviceGen, usedTopLevelNames));
	}
	}
	}

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

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

	_linked = true;
	}

	@override
	String get package => descriptor.package;
	@override
	String get classname => '';
	@override
	String get fullName => descriptor.package;
	@override
	FileGenerator get fileGen => this;
	@override
	ProtobufContainer get parent => null;
	@override
	List<int> get fieldPath => [];

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

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

	var mainWriter = generateMainFile(config);
	var enumWriter = generateEnumFile(config);

	final files = [
	makeFile('.pb.dart', mainWriter.toString()),
	makeFile('.pbenum.dart', enumWriter.toString()),
	makeFile('.pbjson.dart', generateJsonFile(config)),
	];

	if (options.generateMetadata) {
	files.addAll([
	makeFile('.pb.dart.meta',
	mainWriter.sourceLocationInfo.writeToJson().toString()),
	makeFile('.pbenum.dart.meta',
	enumWriter.sourceLocationInfo.writeToJson().toString())
	]);
	}
	if (options.useGrpc) {
	if (grpcGenerators.isNotEmpty) {
	files.add(makeFile('.pbgrpc.dart', generateGrpcFile(config)));
	}
	} else {
	files.add(makeFile('.pbserver.dart', generateServerFile(config)));
	}
	return files;
	}

	/// Creates an IndentingWriter with metadata generation enabled or disabled.
	IndentingWriter makeWriter() => IndentingWriter(
	filename: options.generateMetadata ? descriptor.name : null);

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

	writeMainHeader(out, config);

	// Generate code.
	for (var 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.
	var className = extensionClassName(descriptor, usedTopLevelNames);
	out.addBlock('class $className {', '}\n', () {
	for (var x in extensionGenerators) {
	x.generate(out);
	}
	out.println(
	'static void registerAllExtensions($protobufImportPrefix.ExtensionRegistry '
	'registry) {');
	for (var x in extensionGenerators) {
	out.println(' registry.add(${x.name});');
	}
	out.println('}');
	});
	}

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

	/// 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(_asyncImport);
	}

	out.println(_coreImport);
	out.println();

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

	if (_needsProtobufImport) {
	out.println(_protobufImport);
	out.println();
	}

	final mixinImports = findMixinImports();
	for (var libraryUri in mixinImports) {
	out.println("import '$libraryUri' as $mixinImportPrefix;");
	}
	if (mixinImports.isNotEmpty) out.println();

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

	for (var publicDependency in descriptor.publicDependency) {
	_writeExport(out, config,
	Uri.file(descriptor.dependency[publicDependency]), '.pb.dart');
	}

	// Export enums in main file for backward compatibility.
	if (enumCount > 0) {
	var 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 sorted list of imports needed to support all mixins.
	List<String> findMixinImports() {
	var mixins = <PbMixin>{};
	for (var m in messageGenerators) {
	m.addMixinsTo(mixins);
	}

	return mixins
	.map((mixin) => mixin.importFrom)
	.toSet()
	.toList(growable: false)
	..sort();
	}

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

	var out = makeWriter();
	_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');
	out.println(_coreImport);
	out.println(_protobufImport);
	out.println();
	}

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

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

	return out;
	}

	/// Returns the number of enum types generated in the .pbenum.dart file.
	int get enumCount {
	var count = enumGenerators.length;
	for (var 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 StateError('not linked');
	var out = makeWriter();
	_writeHeading(out,
	extraIgnores: {'deprecated_member_use_from_same_package'});

	if (serviceGenerators.isNotEmpty) {
	out.println(_asyncImport);
	out.println();
	out.println(_protobufImport);
	out.println();
	out.println(_coreImport);
	}

	// Import .pb.dart files needed for requests and responses.
	var imports = <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();
	}

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

	for (var 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 StateError('not linked');
	var out = makeWriter();
	_writeHeading(out);

	out.println(_asyncImport);
	out.println();
	out.println(_coreImport);
	out.println();
	out.println(_grpcImport);

	// Import .pb.dart files needed for requests and responses.
	var imports = <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());
	}

	void writeBinaryDescriptor(IndentingWriter out, String identifierName,
	String name, GeneratedMessage descriptor) {
	var descriptorText = base64Encode(descriptor.writeToBuffer());
	out.println('/// Descriptor for `$name`. Decode as a '
	'`${descriptor.info_.qualifiedMessageName}`.');
	out.println('final $_typedDataImportPrefix.Uint8List '
	'$identifierName = '
	'$_convertImportPrefix.base64Decode(\'$descriptorText\');');
	}

	/// Returns the contents of the .pbjson.dart file for this .proto file.
	String generateJsonFile(
	[OutputConfiguration config = const DefaultOutputConfiguration()]) {
	if (!_linked) throw StateError('not linked');
	var out = makeWriter();
	_writeHeading(out,
	extraIgnores: {'deprecated_member_use_from_same_package'});

	out.println(_coreImport);
	out.println(_convertImport);
	out.println(_typedDataImport);
	// 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);
	writeBinaryDescriptor(
	out, e.binaryDescriptorName, e._descriptor.name, e._descriptor);
	}
	for (var m in messageGenerators) {
	m.generateConstants(out);
	writeBinaryDescriptor(
	out, m.binaryDescriptorName, m._descriptor.name, m._descriptor);
	}
	for (var s in serviceGenerators) {
	s.generateConstants(out);
	writeBinaryDescriptor(
	out, s.binaryDescriptorName, s._descriptor.name, s._descriptor);
	}

	return out.toString();
	}

	/// Returns the generator for each .pbjson.dart file the generated
	/// .pbjson.dart needs to import.
	Set<FileGenerator> _findJsonProtosToImport() {
	var imports = 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, {
	Set<String> extraIgnores = const <String>{},
	}) {
	final ignores = ({
	..._ignores,
	...extraIgnores,
	}).toList()
	..sort();

	out.println('''
	///
	// Generated code. Do not modify.
	// source: ${descriptor.name}
	//
	// @dart = 2.12
	// ignore_for_file: ${ignores.join(',')}
	''');
	}

	/// 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) {
	var resolvedImport =
	config.resolveImport(target.protoFileUri, protoFileUri, extension);
	out.print("import '$resolvedImport'");

	// .pb.dart files should always be prefixed--the protoFileUri check
	// will evaluate to true not just for the main .pb.dart file based off
	// the proto file, but also for the .pbserver.dart, .pbgrpc.dart files.
	if ((extension == '.pb.dart') \|\| protoFileUri != target.protoFileUri) {
	out.print(' as ${target.fileImportPrefix}');
	}
	out.println(';');
	}

	/// Writes an export of a pb.dart file corresponding to a .proto file.
	/// (Possibly the same .proto file.)
	void _writeExport(IndentingWriter out, OutputConfiguration config, Uri target,
	String extension) {
	var resolvedImport = config.resolveImport(target, protoFileUri, extension);
	out.println("export '$resolvedImport';");
	}
	}

	const _ignores = {
	'annotate_overrides',
	'directives_ordering',
	'camel_case_types',
	'constant_identifier_names',
	'library_prefixes',
	'non_constant_identifier_names',
	'prefer_final_fields',
	'return_of_invalid_type',
	'unnecessary_const',
	'unnecessary_import',
	'unnecessary_this',
	'unused_import',
	'unused_shown_name',
	};