Generate common types into a separate library

pkg/analyzer_plugin/tool/spec/codegen_protocol_common.dart

Index: pkg/analyzer_plugin/tool/spec/codegen_protocol_common.dart
diff --git a/pkg/analyzer_plugin/tool/spec/codegen_protocol_common.dart b/pkg/analyzer_plugin/tool/spec/codegen_protocol_common.dart
new file mode 100644
index 0000000000000000000000000000000000000000..08bfb70f06242217929b4a6659627ca5c0c735f8
--- /dev/null
+++ b/pkg/analyzer_plugin/tool/spec/codegen_protocol_common.dart
@@ -0,0 +1,53 @@
+// Copyright (c) 2017, 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.
+
+import 'package:analyzer/src/codegen/tools.dart';
+import 'package:front_end/src/codegen/tools.dart';
+import 'package:path/path.dart' as path;
+
+import 'api.dart';
+import 'codegen_dart_protocol.dart';
+import 'from_html.dart';
+import 'implied_types.dart';
+
+final GeneratedFile target =
+    new GeneratedFile('lib/protocol/protocol_common.dart', (String pkgPath) {
+  CodegenCommonVisitor visitor =
+      new CodegenCommonVisitor(path.basename(pkgPath), readApi(pkgPath));
+  return visitor.collectCode(visitor.visitApi);
+});
+
+/**
+ * A visitor that produces Dart code defining the common types associated with
+ * the API.
+ */
+class CodegenCommonVisitor extends CodegenProtocolVisitor {
+  /**
+   * Initialize a newly created visitor to generate code in the package with the
+   * given [packageName] corresponding to the types in the given [api] that are
+   * common to multiple protocols.
+   */
+  CodegenCommonVisitor(String packageName, Api api) : super(packageName, api);
+
+  @override
+  void emitImports() {
+    writeln("import 'dart:convert' hide JsonDecoder;");
+    writeln();
+    writeln("import 'package:analyzer/src/generated/utilities_general.dart';");
+    writeln("import 'package:$packageName/protocol/protocol.dart';");
+    writeln(
+        "import 'package:$packageName/src/protocol/protocol_internal.dart';");
+  }
+
+  @override
+  List<ImpliedType> getClassesToEmit() {
+    List<ImpliedType> types = impliedTypes.values.where((ImpliedType type) {
+      ApiNode node = type.apiNode;
+      return node is TypeDefinition && node.isExternal;
+    }).toList();
+    types.sort((first, second) =>
+        capitalize(first.camelName).compareTo(capitalize(second.camelName)));
+    return types;
+  }
+}