Removed fixed dependencies

packages/analyzer/tool/summary/generate.dart

+// Copyright (c) 2015, 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.
+
+/**
+ * This file contains code to generate serialization/deserialization logic for
+ * summaries based on an "IDL" description of the summary format (written in
+ * stylized Dart).
+ *
+ * For each class in the "IDL" input, two corresponding classes are generated:
+ * - A class with the same name which represents deserialized summary data in
+ *   memory.  This class has read-only semantics.
+ * - A "builder" class which can be used to generate serialized summary data.
+ *   This class has write-only semantics.
+ *
+ * Each of the "builder" classes has a single `finish` method which writes
+ * the entity being built into the given FlatBuffer and returns the `Offset`
+ * reference to it.
+ */
+library analyzer.tool.summary.generate;
+
+import 'dart:convert';
+import 'dart:io' hide File;
+
+import 'package:analyzer/analyzer.dart';
+import 'package:analyzer/dart/ast/token.dart';
+import 'package:analyzer/error/listener.dart';
+import 'package:analyzer/file_system/file_system.dart';
+import 'package:analyzer/file_system/physical_file_system.dart';
+import 'package:analyzer/src/codegen/tools.dart';
+import 'package:analyzer/src/dart/scanner/reader.dart';
+import 'package:analyzer/src/dart/scanner/scanner.dart';
+import 'package:analyzer/src/generated/parser.dart';
+import 'package:analyzer/src/generated/source.dart';
+import 'package:path/path.dart';
+
+import 'idl_model.dart' as idlModel;
+
+main() {
+  String script = Platform.script.toFilePath(windows: Platform.isWindows);
+  String pkgPath = normalize(join(dirname(script), '..', '..'));
+  GeneratedContent.generateAll(pkgPath, allTargets);
+}
+
+final List<GeneratedContent> allTargets = <GeneratedContent>[
+  formatTarget,
+  schemaTarget
+];
+
+final GeneratedFile formatTarget =
+    new GeneratedFile('lib/src/summary/format.dart', (String pkgPath) {
+  _CodeGenerator codeGenerator = new _CodeGenerator(pkgPath);
+  codeGenerator.generateFormatCode();
+  return codeGenerator._outBuffer.toString();
+});
+
+final GeneratedFile schemaTarget =
+    new GeneratedFile('lib/src/summary/format.fbs', (String pkgPath) {
+  _CodeGenerator codeGenerator = new _CodeGenerator(pkgPath);
+  codeGenerator.generateFlatBufferSchema();
+  return codeGenerator._outBuffer.toString();
+});
+
+typedef String _StringToString(String s);
+
+class _CodeGenerator {
+  static const String _throwDeprecated =
+      "throw new UnimplementedError('attempt to access deprecated field')";
+
+  /**
+   * Buffer in which generated code is accumulated.
+   */
+  final StringBuffer _outBuffer = new StringBuffer();
+
+  /**
+   * Current indentation level.
+   */
+  String _indentation = '';
+
+  /**
+   * Semantic model of the "IDL" input file.
+   */
+  idlModel.Idl _idl;
+
+  _CodeGenerator(String pkgPath) {
+    // Parse the input "IDL" file.
+    PhysicalResourceProvider provider = new PhysicalResourceProvider(
+        PhysicalResourceProvider.NORMALIZE_EOL_ALWAYS);
+    String idlPath = join(pkgPath, 'lib', 'src', 'summary', 'idl.dart');
+    File idlFile = provider.getFile(idlPath);
+    Source idlSource = provider.getFile(idlPath).createSource();
+    String idlText = idlFile.readAsStringSync();
+    BooleanErrorListener errorListener = new BooleanErrorListener();
+    CharacterReader idlReader = new CharSequenceReader(idlText);
+    Scanner scanner = new Scanner(idlSource, idlReader, errorListener);
+    Token tokenStream = scanner.tokenize();
+    LineInfo lineInfo = new LineInfo(scanner.lineStarts);
+    Parser parser = new Parser(idlSource, new BooleanErrorListener());
+    CompilationUnit idlParsed = parser.parseCompilationUnit(tokenStream);
+    // Extract a description of the IDL and make sure it is valid.
+    extractIdl(lineInfo, idlParsed);
+    checkIdl();
+  }
+
+  /**
+   * Perform basic sanity checking of the IDL (over and above that done by
+   * [extractIdl]).
+   */
+  void checkIdl() {
+    _idl.classes.forEach((String name, idlModel.ClassDeclaration cls) {
+      if (cls.fileIdentifier != null) {
+        if (cls.fileIdentifier.length != 4) {
+          throw new Exception('$name: file identifier must be 4 characters');
+        }
+        for (int i = 0; i < cls.fileIdentifier.length; i++) {
+          if (cls.fileIdentifier.codeUnitAt(i) >= 256) {
+            throw new Exception(
+                '$name: file identifier must be encodable as Latin-1');
+          }
+        }
+      }
+      Map<int, String> idsUsed = <int, String>{};
+      for (idlModel.FieldDeclaration field in cls.allFields) {
+        String fieldName = field.name;
+        idlModel.FieldType type = field.type;
+        if (type.isList) {
+          if (_idl.classes.containsKey(type.typeName)) {
+            // List of classes is ok
+          } else if (_idl.enums.containsKey(type.typeName)) {
+            // List of enums is ok
+          } else if (type.typeName == 'bool') {
+            // List of booleans is ok
+          } else if (type.typeName == 'int') {
+            // List of ints is ok
+          } else if (type.typeName == 'double') {
+            // List of doubles is ok
+          } else if (type.typeName == 'String') {
+            // List of strings is ok
+          } else {
+            throw new Exception(
+                '$name.$fieldName: illegal type (list of ${type.typeName})');
+          }
+        }
+        if (idsUsed.containsKey(field.id)) {
+          throw new Exception('$name.$fieldName: id ${field.id} already used by'
+              ' ${idsUsed[field.id]}');
+        }
+        idsUsed[field.id] = fieldName;
+      }
+      for (int i = 0; i < idsUsed.length; i++) {
+        if (!idsUsed.containsKey(i)) {
+          throw new Exception('$name: no field uses id $i');
+        }
+      }
+    });
+  }
+
+  /**
+   * Generate a string representing the Dart type which should be used to
+   * represent [type] when deserialized.
+   */
+  String dartType(idlModel.FieldType type) {
+    String baseType = idlPrefix(type.typeName);
+    if (type.isList) {
+      return 'List<$baseType>';
+    } else {
+      return baseType;
+    }
+  }
+
+  /**
+   * Generate a Dart expression representing the default value for a field
+   * having the given [type], or `null` if there is no default value.
+   *
+   * If [builder] is `true`, the returned type should be appropriate for use in
+   * a builder class.
+   */
+  String defaultValue(idlModel.FieldType type, bool builder) {
+    if (type.isList) {
+      if (builder) {
+        idlModel.FieldType elementType =
+            new idlModel.FieldType(type.typeName, false);
+        return '<${encodedType(elementType)}>[]';
+      } else {
+        return 'const <${idlPrefix(type.typeName)}>[]';
+      }
+    } else if (_idl.enums.containsKey(type.typeName)) {
+      return '${idlPrefix(type.typeName)}.'
+          '${_idl.enums[type.typeName].values[0].name}';
+    } else if (type.typeName == 'int') {
+      return '0';
+    } else if (type.typeName == 'String') {
+      return "''";
+    } else if (type.typeName == 'bool') {
+      return 'false';
+    } else {
+      return null;
+    }
+  }
+
+  /**
+   * Generate a string representing the Dart type which should be used to
+   * represent [type] while building a serialized data structure.
+   */
+  String encodedType(idlModel.FieldType type) {
+    String typeStr;
+    if (_idl.classes.containsKey(type.typeName)) {
+      typeStr = '${type.typeName}Builder';
+    } else {
+      typeStr = idlPrefix(type.typeName);
+    }
+    if (type.isList) {
+      return 'List<$typeStr>';
+    } else {
+      return typeStr;
+    }
+  }
+
+  /**
+   * Process the AST in [idlParsed] and store the resulting semantic model in
+   * [_idl].  Also perform some error checking.
+   */
+  void extractIdl(LineInfo lineInfo, CompilationUnit idlParsed) {
+    _idl = new idlModel.Idl();
+    for (CompilationUnitMember decl in idlParsed.declarations) {
+      if (decl is ClassDeclaration) {
+        bool isTopLevel = false;
+        String fileIdentifier;
+        String clsName = decl.name.name;
+        for (Annotation annotation in decl.metadata) {
+          if (annotation.arguments != null &&
+              annotation.name.name == 'TopLevel' &&
+              annotation.constructorName == null) {
+            isTopLevel = true;
+            if (annotation.arguments == null) {
+              throw new Exception(
+                  'Class `$clsName`: TopLevel requires parenthesis');
+            }
+            if (annotation.constructorName != null) {
+              throw new Exception(
+                  "Class `$clsName`: TopLevel doesn't have named constructors");
+            }
+            if (annotation.arguments.arguments.length == 1) {
+              Expression arg = annotation.arguments.arguments[0];
+              if (arg is StringLiteral) {
+                fileIdentifier = arg.stringValue;
+              } else {
+                throw new Exception(
+                    'Class `$clsName`: TopLevel argument must be a string'
+                    ' literal');
+              }
+            } else if (annotation.arguments.arguments.length != 0) {
+              throw new Exception(
+                  'Class `$clsName`: TopLevel requires 0 or 1 arguments');
+            }
+          }
+        }
+        String doc = _getNodeDoc(lineInfo, decl);
+        idlModel.ClassDeclaration cls = new idlModel.ClassDeclaration(
+            doc, clsName, isTopLevel, fileIdentifier);
+        _idl.classes[clsName] = cls;
+        String expectedBase = 'base.SummaryClass';
+        if (decl.extendsClause == null ||
+            decl.extendsClause.superclass.name.name != expectedBase) {
+          throw new Exception(
+              'Class `$clsName` needs to extend `$expectedBase`');
+        }
+        for (ClassMember classMember in decl.members) {
+          if (classMember is MethodDeclaration && classMember.isGetter) {
+            String desc = '$clsName.${classMember.name.name}';
+            TypeName type = classMember.returnType;
+            if (type == null) {
+              throw new Exception('Class member needs a type: $desc');
+            }
+            bool isList = false;
+            if (type.name.name == 'List' &&
+                type.typeArguments != null &&
+                type.typeArguments.arguments.length == 1) {
+              isList = true;
+              type = type.typeArguments.arguments[0];
+            }
+            if (type.typeArguments != null) {
+              throw new Exception('Cannot handle type arguments in `$type`');
+            }
+            int id;
+            bool isDeprecated = false;
+            bool isInformative = false;
+            for (Annotation annotation in classMember.metadata) {
+              if (annotation.name.name == 'Id') {
+                if (id != null) {
+                  throw new Exception(
+                      'Duplicate @id annotation ($classMember)');
+                }
+                if (annotation.arguments.arguments.length != 1) {
+                  throw new Exception(
+                      '@Id must be passed exactly one argument ($desc)');
+                }
+                Expression expression = annotation.arguments.arguments[0];
+                if (expression is IntegerLiteral) {
+                  id = expression.value;
+                } else {
+                  throw new Exception(
+                      '@Id parameter must be an integer literal ($desc)');
+                }
+              } else if (annotation.name.name == 'deprecated') {
+                if (annotation.arguments != null) {
+                  throw new Exception('@deprecated does not take args ($desc)');
+                }
+                isDeprecated = true;
+              } else if (annotation.name.name == 'informative') {
+                isInformative = true;
+              }
+            }
+            if (id == null) {
+              throw new Exception('Missing @id annotation ($desc)');
+            }
+            String doc = _getNodeDoc(lineInfo, classMember);
+            idlModel.FieldType fieldType =
+                new idlModel.FieldType(type.name.name, isList);
+            cls.allFields.add(new idlModel.FieldDeclaration(
+                doc,
+                classMember.name.name,
+                fieldType,
+                id,
+                isDeprecated,
+                isInformative));
+          } else if (classMember is ConstructorDeclaration &&
+              classMember.name.name == 'fromBuffer') {
+            // Ignore `fromBuffer` declarations; they simply forward to the
+            // read functions generated by [_generateReadFunction].
+          } else {
+            throw new Exception('Unexpected class member `$classMember`');
+          }
+        }
+      } else if (decl is EnumDeclaration) {
+        String doc = _getNodeDoc(lineInfo, decl);
+        idlModel.EnumDeclaration enm =
+            new idlModel.EnumDeclaration(doc, decl.name.name);
+        _idl.enums[enm.name] = enm;
+        for (EnumConstantDeclaration constDecl in decl.constants) {
+          String doc = _getNodeDoc(lineInfo, constDecl);
+          enm.values
+              .add(new idlModel.EnumValueDeclaration(doc, constDecl.name.name));
+        }
+      } else if (decl is TopLevelVariableDeclaration) {
+        // Ignore top level variable declarations; they are present just to make
+        // the IDL analyze without warnings.
+      } else {
+        throw new Exception('Unexpected declaration `$decl`');
+      }
+    }
+  }
+
+  /**
+   * Generate a string representing the FlatBuffer schema type which should be
+   * used to represent [type].
+   */
+  String fbsType(idlModel.FieldType type) {
+    String typeStr;
+    switch (type.typeName) {
+      case 'bool':
+        typeStr = 'bool';
+        break;
+      case 'double':
+        typeStr = 'double';
+        break;
+      case 'int':
+        typeStr = 'uint';
+        break;
+      case 'String':
+        typeStr = 'string';
+        break;
+      default:
+        typeStr = type.typeName;
+        break;
+    }
+    if (type.isList) {
+      // FlatBuffers don't natively support a packed list of booleans, so we
+      // treat it as a list of unsigned bytes, which is a compatible data
+      // structure.
+      if (typeStr == 'bool') {
+        typeStr = 'ubyte';
+      }
+      return '[$typeStr]';
+    } else {
+      return typeStr;
+    }
+  }
+
+  /**
+   * Entry point to the code generator when generating the "format.fbs" file.
+   */
+  void generateFlatBufferSchema() {
+    outputHeader();
+    for (idlModel.EnumDeclaration enm in _idl.enums.values) {
+      out();
+      outDoc(enm.documentation);
+      out('enum ${enm.name} : byte {');
+      indent(() {
+        for (int i = 0; i < enm.values.length; i++) {
+          idlModel.EnumValueDeclaration value = enm.values[i];
+          if (i != 0) {
+            out();
+          }
+          String suffix = i < enm.values.length - 1 ? ',' : '';
+          outDoc(value.documentation);
+          out('${value.name}$suffix');
+        }
+      });
+      out('}');
+    }
+    for (idlModel.ClassDeclaration cls in _idl.classes.values) {
+      out();
+      outDoc(cls.documentation);
+      out('table ${cls.name} {');
+      indent(() {
+        for (int i = 0; i < cls.allFields.length; i++) {
+          idlModel.FieldDeclaration field = cls.allFields[i];
+          if (i != 0) {
+            out();
+          }
+          outDoc(field.documentation);
+          List<String> attributes = <String>['id: ${field.id}'];
+          if (field.isDeprecated) {
+            attributes.add('deprecated');
+          }
+          String attrText = attributes.join(', ');
+          out('${field.name}:${fbsType(field.type)} ($attrText);');
+        }
+      });
+      out('}');
+    }
+    out();
+    // Standard flatbuffers only support one root type.  We support multiple
+    // root types.  For now work around this by forcing PackageBundle to be the
+    // root type.  TODO(paulberry): come up with a better solution.
+    idlModel.ClassDeclaration rootType = _idl.classes['PackageBundle'];
+    out('root_type ${rootType.name};');
+    if (rootType.fileIdentifier != null) {
+      out();
+      out('file_identifier ${quoted(rootType.fileIdentifier)};');
+    }
+  }
+
+  /**
+   * Entry point to the code generator when generating the "format.dart" file.
+   */
+  void generateFormatCode() {
+    outputHeader();
+    out('library analyzer.src.summary.format;');
+    out();
+    out("import 'flat_buffers.dart' as fb;");
+    out("import 'idl.dart' as idl;");
+    out("import 'dart:convert' as convert;");
+    out("import 'api_signature.dart' as api_sig;");
+    out();
+    for (idlModel.EnumDeclaration enm in _idl.enums.values) {
+      _generateEnumReader(enm);
+      out();
+    }
+    for (idlModel.ClassDeclaration cls in _idl.classes.values) {
+      _generateBuilder(cls);
+      out();
+      if (cls.isTopLevel) {
+        _generateReadFunction(cls);
+        out();
+      }
+      _generateReader(cls);
+      out();
+      _generateImpl(cls);
+      out();
+      _generateMixin(cls);
+      out();
+    }
+  }
+
+  /**
+   * Add the prefix `idl.` to a type name, unless that type name is the name of
+   * a built-in type.
+   */
+  String idlPrefix(String s) {
+    switch (s) {
+      case 'bool':
+      case 'double':
+      case 'int':
+      case 'String':
+        return s;
+      default:
+        return 'idl.$s';
+    }
+  }
+
+  /**
+   * Execute [callback] with two spaces added to [_indentation].
+   */
+  void indent(void callback()) {
+    String oldIndentation = _indentation;
+    try {
+      _indentation += '  ';
+      callback();
+    } finally {
+      _indentation = oldIndentation;
+    }
+  }
+
+  /**
+   * Add the string [s] to the output as a single line, indenting as
+   * appropriate.
+   */
+  void out([String s = '']) {
+    if (s == '') {
+      _outBuffer.writeln('');
+    } else {
+      _outBuffer.writeln('$_indentation$s');
+    }
+  }
+
+  void outDoc(String documentation) {
+    if (documentation != null) {
+      documentation.split('\n').forEach(out);
+    }
+  }
+
+  void outputHeader() {
+    out('// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file');
+    out('// for details. All rights reserved. Use of this source code is governed by a');
+    out('// BSD-style license that can be found in the LICENSE file.');
+    out('//');
+    out('// This file has been automatically generated.  Please do not edit it manually.');
+    out('// To regenerate the file, use the script "pkg/analyzer/tool/generate_files".');
+    out();
+  }
+
+  /**
+   * Enclose [s] in quotes, escaping as necessary.
+   */
+  String quoted(String s) {
+    return JSON.encode(s);
+  }
+
+  void _generateBuilder(idlModel.ClassDeclaration cls) {
+    String name = cls.name;
+    String builderName = name + 'Builder';
+    String mixinName = '_${name}Mixin';
+    List<String> constructorParams = <String>[];
+    out('class $builderName extends Object with $mixinName '
+        'implements ${idlPrefix(name)} {');
+    indent(() {
+      // Generate fields.
+      for (idlModel.FieldDeclaration field in cls.fields) {
+        String fieldName = field.name;
+        idlModel.FieldType type = field.type;
+        String typeStr = encodedType(type);
+        out('$typeStr _$fieldName;');
+      }
+      // Generate getters and setters.
+      for (idlModel.FieldDeclaration field in cls.allFields) {
+        String fieldName = field.name;
+        idlModel.FieldType fieldType = field.type;
+        String typeStr = encodedType(fieldType);
+        String def = defaultValue(fieldType, true);
+        String defSuffix = def == null ? '' : ' ??= $def';
+        out();
+        out('@override');
+        if (field.isDeprecated) {
+          out('$typeStr get $fieldName => $_throwDeprecated;');
+        } else {
+          out('$typeStr get $fieldName => _$fieldName$defSuffix;');
+          out();
+          outDoc(field.documentation);
+          constructorParams.add('$typeStr $fieldName');
+          out('void set $fieldName($typeStr value) {');
+          indent(() {
+            String stateFieldName = '_' + fieldName;
+            // Validate that int(s) are non-negative.
+            if (fieldType.typeName == 'int') {
+              if (!fieldType.isList) {
+                out('assert(value == null || value >= 0);');
+              } else {
+                out('assert(value == null || value.every((e) => e >= 0));');
+              }
+            }
+            // Set the value.
+            out('this.$stateFieldName = value;');
+          });
+          out('}');
+        }
+      }
+      // Generate constructor.
+      out();
+      out('$builderName({${constructorParams.join(', ')}})');
+      List<idlModel.FieldDeclaration> fields = cls.fields.toList();
+      for (int i = 0; i < fields.length; i++) {
+        idlModel.FieldDeclaration field = fields[i];
+        String prefix = i == 0 ? '  : ' : '    ';
+        String suffix = i == fields.length - 1 ? ';' : ',';
+        out('${prefix}_${field.name} = ${field.name}$suffix');
+      }
+      // Generate flushInformative().
+      {
+        out();
+        out('/**');
+        out(' * Flush [informative] data recursively.');
+        out(' */');
+        out('void flushInformative() {');
+        indent(() {
+          for (idlModel.FieldDeclaration field in cls.fields) {
+            idlModel.FieldType fieldType = field.type;
+            String valueName = '_' + field.name;
+            if (field.isInformative) {
+              out('$valueName = null;');
+            } else if (_idl.classes.containsKey(fieldType.typeName)) {
+              if (fieldType.isList) {
+                out('$valueName?.forEach((b) => b.flushInformative());');
+              } else {
+                out('$valueName?.flushInformative();');
+              }
+            }
+          }
+        });
+        out('}');
+      }
+      // Generate collectApiSignature().
+      {
+        out();
+        out('/**');
+        out(' * Accumulate non-[informative] data into [signature].');
+        out(' */');
+        out('void collectApiSignature(api_sig.ApiSignature signature) {');
+        indent(() {
+          List<idlModel.FieldDeclaration> sortedFields = cls.fields.toList()
+            ..sort((idlModel.FieldDeclaration a, idlModel.FieldDeclaration b) =>
+                a.id.compareTo(b.id));
+          for (idlModel.FieldDeclaration field in sortedFields) {
+            if (field.isInformative) {
+              continue;
+            }
+            String ref = 'this._${field.name}';
+            if (field.type.isList) {
+              out('if ($ref == null) {');
+              indent(() {
+                out('signature.addInt(0);');
+              });
+              out('} else {');
+              indent(() {
+                out('signature.addInt($ref.length);');
+                out('for (var x in $ref) {');
+                indent(() {
+                  _generateSignatureCall(field.type.typeName, 'x', false);
+                });
+                out('}');
+              });
+              out('}');
+            } else {
+              _generateSignatureCall(field.type.typeName, ref, true);
+            }
+          }
+        });
+        out('}');
+      }
+      // Generate finish.
+      if (cls.isTopLevel) {
+        out();
+        out('List<int> toBuffer() {');
+        indent(() {
+          out('fb.Builder fbBuilder = new fb.Builder();');
+          String fileId = cls.fileIdentifier == null
+              ? ''
+              : ', ${quoted(cls.fileIdentifier)}';
+          out('return fbBuilder.finish(finish(fbBuilder)$fileId);');
+        });
+        out('}');
+      }
+      out();
+      out('fb.Offset finish(fb.Builder fbBuilder) {');
+      indent(() {
+        // Write objects and remember Offset(s).
+        for (idlModel.FieldDeclaration field in cls.fields) {
+          idlModel.FieldType fieldType = field.type;
+          String offsetName = 'offset_' + field.name;
+          if (fieldType.isList ||
+              fieldType.typeName == 'String' ||
+              _idl.classes.containsKey(fieldType.typeName)) {
+            out('fb.Offset $offsetName;');
+          }
+        }
+        for (idlModel.FieldDeclaration field in cls.fields) {
+          idlModel.FieldType fieldType = field.type;
+          String valueName = '_' + field.name;
+          String offsetName = 'offset_' + field.name;
+          String condition;
+          String writeCode;
+          if (fieldType.isList) {
+            condition = ' || $valueName.isEmpty';
+            if (_idl.classes.containsKey(fieldType.typeName)) {
+              String itemCode = 'b.finish(fbBuilder)';
+              String listCode = '$valueName.map((b) => $itemCode).toList()';
+              writeCode = '$offsetName = fbBuilder.writeList($listCode);';
+            } else if (_idl.enums.containsKey(fieldType.typeName)) {
+              String itemCode = 'b.index';
+              String listCode = '$valueName.map((b) => $itemCode).toList()';
+              writeCode = '$offsetName = fbBuilder.writeListUint8($listCode);';
+            } else if (fieldType.typeName == 'bool') {
+              writeCode = '$offsetName = fbBuilder.writeListBool($valueName);';
+            } else if (fieldType.typeName == 'int') {
+              writeCode =
+                  '$offsetName = fbBuilder.writeListUint32($valueName);';
+            } else if (fieldType.typeName == 'double') {
+              writeCode =
+                  '$offsetName = fbBuilder.writeListFloat64($valueName);';
+            } else {
+              assert(fieldType.typeName == 'String');
+              String itemCode = 'fbBuilder.writeString(b)';
+              String listCode = '$valueName.map((b) => $itemCode).toList()';
+              writeCode = '$offsetName = fbBuilder.writeList($listCode);';
+            }
+          } else if (fieldType.typeName == 'String') {
+            writeCode = '$offsetName = fbBuilder.writeString($valueName);';
+          } else if (_idl.classes.containsKey(fieldType.typeName)) {
+            writeCode = '$offsetName = $valueName.finish(fbBuilder);';
+          }
+          if (writeCode != null) {
+            if (condition == null) {
+              out('if ($valueName != null) {');
+            } else {
+              out('if (!($valueName == null$condition)) {');
+            }
+            indent(() {
+              out(writeCode);
+            });
+            out('}');
+          }
+        }
+        // Write the table.
+        out('fbBuilder.startTable();');
+        for (idlModel.FieldDeclaration field in cls.fields) {
+          int index = field.id;
+          idlModel.FieldType fieldType = field.type;
+          String valueName = '_' + field.name;
+          String condition = '$valueName != null';
+          String writeCode;
+          if (fieldType.isList ||
+              fieldType.typeName == 'String' ||
+              _idl.classes.containsKey(fieldType.typeName)) {
+            String offsetName = 'offset_' + field.name;
+            condition = '$offsetName != null';
+            writeCode = 'fbBuilder.addOffset($index, $offsetName);';
+          } else if (fieldType.typeName == 'bool') {
+            condition = '$valueName == true';
+            writeCode = 'fbBuilder.addBool($index, true);';
+          } else if (fieldType.typeName == 'int') {
+            condition += ' && $valueName != ${defaultValue(fieldType, true)}';
+            writeCode = 'fbBuilder.addUint32($index, $valueName);';
+          } else if (_idl.enums.containsKey(fieldType.typeName)) {
+            condition += ' && $valueName != ${defaultValue(fieldType, true)}';
+            writeCode = 'fbBuilder.addUint8($index, $valueName.index);';
+          }
+          if (writeCode == null) {
+            throw new UnimplementedError('Writing type ${fieldType.typeName}');
+          }
+          out('if ($condition) {');
+          indent(() {
+            out(writeCode);
+          });
+          out('}');
+        }
+        out('return fbBuilder.endTable();');
+      });
+      out('}');
+    });
+    out('}');
+  }
+
+  void _generateEnumReader(idlModel.EnumDeclaration enm) {
+    String name = enm.name;
+    String readerName = '_${name}Reader';
+    String count = '${idlPrefix(name)}.values.length';
+    String def = '${idlPrefix(name)}.${enm.values[0].name}';
+    out('class $readerName extends fb.Reader<${idlPrefix(name)}> {');
+    indent(() {
+      out('const $readerName() : super();');
+      out();
+      out('@override');
+      out('int get size => 1;');
+      out();
+      out('@override');
+      out('${idlPrefix(name)} read(fb.BufferContext bc, int offset) {');
+      indent(() {
+        out('int index = const fb.Uint8Reader().read(bc, offset);');
+        out('return index < $count ? ${idlPrefix(name)}.values[index] : $def;');
+      });
+      out('}');
+    });
+    out('}');
+  }
+
+  void _generateImpl(idlModel.ClassDeclaration cls) {
+    String name = cls.name;
+    String implName = '_${name}Impl';
+    String mixinName = '_${name}Mixin';
+    out('class $implName extends Object with $mixinName'
+        ' implements ${idlPrefix(name)} {');
+    indent(() {
+      out('final fb.BufferContext _bc;');
+      out('final int _bcOffset;');
+      out();
+      out('$implName(this._bc, this._bcOffset);');
+      out();
+      // Write cache fields.
+      for (idlModel.FieldDeclaration field in cls.fields) {
+        String returnType = dartType(field.type);
+        String fieldName = field.name;
+        out('$returnType _$fieldName;');
+      }
+      // Write getters.
+      for (idlModel.FieldDeclaration field in cls.allFields) {
+        int index = field.id;
+        String fieldName = field.name;
+        idlModel.FieldType type = field.type;
+        String typeName = type.typeName;
+        // Prepare "readCode" + "def"
+        String readCode;
+        String def = defaultValue(type, false);
+        if (type.isList) {
+          if (typeName == 'bool') {
+            readCode = 'const fb.BoolListReader()';
+          } else if (typeName == 'int') {
+            readCode = 'const fb.Uint32ListReader()';
+          } else if (typeName == 'double') {
+            readCode = 'const fb.Float64ListReader()';
+          } else if (typeName == 'String') {
+            String itemCode = 'const fb.StringReader()';
+            readCode = 'const fb.ListReader<String>($itemCode)';
+          } else if (_idl.classes.containsKey(typeName)) {
+            String itemCode = 'const _${typeName}Reader()';
+            readCode = 'const fb.ListReader<${idlPrefix(typeName)}>($itemCode)';
+          } else {
+            assert(_idl.enums.containsKey(typeName));
+            String itemCode = 'const _${typeName}Reader()';
+            readCode = 'const fb.ListReader<${idlPrefix(typeName)}>($itemCode)';
+          }
+        } else if (typeName == 'bool') {
+          readCode = 'const fb.BoolReader()';
+        } else if (typeName == 'int') {
+          readCode = 'const fb.Uint32Reader()';
+        } else if (typeName == 'String') {
+          readCode = 'const fb.StringReader()';
+        } else if (_idl.enums.containsKey(typeName)) {
+          readCode = 'const _${typeName}Reader()';
+        } else if (_idl.classes.containsKey(typeName)) {
+          readCode = 'const _${typeName}Reader()';
+        }
+        assert(readCode != null);
+        // Write the getter implementation.
+        out();
+        out('@override');
+        String returnType = dartType(type);
+        if (field.isDeprecated) {
+          out('$returnType get $fieldName => $_throwDeprecated;');
+        } else {
+          out('$returnType get $fieldName {');
+          indent(() {
+            String readExpr =
+                '$readCode.vTableGet(_bc, _bcOffset, $index, $def)';
+            out('_$fieldName ??= $readExpr;');
+            out('return _$fieldName;');
+          });
+          out('}');
+        }
+      }
+    });
+    out('}');
+  }
+
+  void _generateMixin(idlModel.ClassDeclaration cls) {
+    String name = cls.name;
+    String mixinName = '_${name}Mixin';
+    out('abstract class $mixinName implements ${idlPrefix(name)} {');
+    indent(() {
+      // Write toJson().
+      out('@override');
+      out('Map<String, Object> toJson() {');
+      indent(() {
+        out('Map<String, Object> _result = <String, Object>{};');
+        for (idlModel.FieldDeclaration field in cls.fields) {
+          String condition;
+          if (field.type.isList) {
+            condition = '${field.name}.isNotEmpty';
+          } else {
+            condition = '${field.name} != ${defaultValue(field.type, false)}';
+          }
+          _StringToString convertItem;
+          if (_idl.classes.containsKey(field.type.typeName)) {
+            convertItem = (String name) => '$name.toJson()';
+          } else if (_idl.enums.containsKey(field.type.typeName)) {
+            // TODO(paulberry): it would be better to generate a const list of
+            // strings so that we don't have to do this kludge.
+            convertItem = (String name) => "$name.toString().split('.')[1]";
+          } else if (field.type.typeName == 'double') {
+            convertItem =
+                (String name) => '$name.isFinite ? $name : $name.toString()';
+          }
+          String convertField;
+          if (convertItem == null) {
+            convertField = field.name;
+          } else if (field.type.isList) {
+            convertField = '${field.name}.map((_value) =>'
+                ' ${convertItem('_value')}).toList()';
+          } else {
+            convertField = convertItem(field.name);
+          }
+          String storeField = '_result[${quoted(field.name)}] = $convertField';
+          out('if ($condition) $storeField;');
+        }
+        out('return _result;');
+      });
+      out('}');
+      out();
+      // Write toMap().
+      out('@override');
+      out('Map<String, Object> toMap() => {');
+      indent(() {
+        for (idlModel.FieldDeclaration field in cls.fields) {
+          String fieldName = field.name;
+          out('${quoted(fieldName)}: $fieldName,');
+        }
+      });
+      out('};');
+      out();
+      // Write toString().
+      out('@override');
+      out('String toString() => convert.JSON.encode(toJson());');
+    });
+    out('}');
+  }
+
+  void _generateReader(idlModel.ClassDeclaration cls) {
+    String name = cls.name;
+    String readerName = '_${name}Reader';
+    String implName = '_${name}Impl';
+    out('class $readerName extends fb.TableReader<$implName> {');
+    indent(() {
+      out('const $readerName();');
+      out();
+      out('@override');
+      out('$implName createObject(fb.BufferContext bc, int offset) => new $implName(bc, offset);');
+    });
+    out('}');
+  }
+
+  void _generateReadFunction(idlModel.ClassDeclaration cls) {
+    String name = cls.name;
+    out('${idlPrefix(name)} read$name(List<int> buffer) {');
+    indent(() {
+      out('fb.BufferContext rootRef = new fb.BufferContext.fromBytes(buffer);');
+      out('return const _${name}Reader().read(rootRef, 0);');
+    });
+    out('}');
+  }
+
+  /**
+   * Generate a call to the appropriate method of [ApiSignature] for the type
+   * [typeName], using the data named by [ref].  If [couldBeNull] is `true`,
+   * generate code to handle the possibility that [ref] is `null` (substituting
+   * in the appropriate default value).
+   */
+  void _generateSignatureCall(String typeName, String ref, bool couldBeNull) {
+    if (_idl.enums.containsKey(typeName)) {
+      if (couldBeNull) {
+        out('signature.addInt($ref == null ? 0 : $ref.index);');
+      } else {
+        out('signature.addInt($ref.index);');
+      }
+    } else if (_idl.classes.containsKey(typeName)) {
+      if (couldBeNull) {
+        out('signature.addBool($ref != null);');
+      }
+      out('$ref?.collectApiSignature(signature);');
+    } else {
+      switch (typeName) {
+        case 'String':
+          if (couldBeNull) {
+            ref += " ?? ''";
+          }
+          out("signature.addString($ref);");
+          break;
+        case 'int':
+          if (couldBeNull) {
+            ref += ' ?? 0';
+          }
+          out('signature.addInt($ref);');
+          break;
+        case 'bool':
+          if (couldBeNull) {
+            ref += ' == true';
+          }
+          out('signature.addBool($ref);');
+          break;
+        case 'double':
+          if (couldBeNull) {
+            ref += ' ?? 0.0';
+          }
+          out('signature.addDouble($ref);');
+          break;
+        default:
+          throw "Don't know how to generate signature call for $typeName";
+      }
+    }
+  }
+
+  /**
+   * Return the documentation text of the given [node], or `null` if the [node]
+   * does not have a comment.  Each line is `\n` separated.
+   */
+  String _getNodeDoc(LineInfo lineInfo, AnnotatedNode node) {
+    Comment comment = node.documentationComment;
+    if (comment != null &&
+        comment.isDocumentation &&
+        comment.tokens.length == 1 &&
+        comment.tokens.first.type == TokenType.MULTI_LINE_COMMENT) {
+      Token token = comment.tokens.first;
+      int column = lineInfo.getLocation(token.offset).columnNumber;
+      String indent = ' ' * (column - 1);
+      return token.lexeme.split('\n').map((String line) {
+        if (line.startsWith(indent)) {
+          line = line.substring(indent.length);
+        }
+        return line;
+      }).join('\n');
+    }
+    return null;
+  }
+}