Switch analysis_server to language 2.12, so null safety, but opt-out files.

This should allow doing partial migration, specifically protocol files,
which are imported by other libraries, but are a small library cycle
that does not import much outside of it.

Change-Id: I904c05d6d5b444ee9a9dbd1f7ada12aabdcc5165
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/193583
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>

pkg/analysis_server/tool/bulk_fix/supported_lints.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 import 'package:analysis_server/src/services/correction/fix_internal.dart';
 
 /// Print lints that are bulk-fixable in a format that can be included in

pkg/analysis_server/tool/code_completion/code_metrics.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 import 'dart:io' as io;
 
 import 'package:analyzer/dart/analysis/analysis_context_collection.dart';

pkg/analysis_server/tool/code_completion/completion_metrics.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 import 'dart:convert';
 import 'dart:io' as io;
 import 'dart:math' as math;

pkg/analysis_server/tool/code_completion/corpus.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 import 'dart:convert';
 import 'dart:io';
 

pkg/analysis_server/tool/code_completion/flutter_metrics.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 import 'dart:io' as io;
 
 import 'package:analysis_server/src/utilities/flutter.dart';

pkg/analysis_server/tool/code_completion/implicit_type_declarations.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 import 'dart:io' as io;
 
 import 'package:analysis_server/src/status/pages.dart';

pkg/analysis_server/tool/code_completion/metrics_util.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 import 'package:analysis_server/src/status/pages.dart';
 import 'package:analyzer/src/generated/utilities_general.dart';
 

pkg/analysis_server/tool/code_completion/output_utilities.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 import 'dart:math' as math;
 
 /// Print the given [table].

pkg/analysis_server/tool/code_completion/relevance_metrics.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 import 'dart:io' as io;
 import 'dart:math' as math;
 

pkg/analysis_server/tool/code_completion/relevance_table_generator.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 import 'dart:convert';
 import 'dart:io' as io;
 
@@ -1592,6 +1594,8 @@ Map<String, Map<String, ProbabilityRange>> keywordRelevance =
 // Copyright (c) 2020, 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 = 2.9
 //
 // This file has been automatically generated. Please do not edit it manually.
 // To regenerate the file, use the script

pkg/analysis_server/tool/code_completion/visitors.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 import 'package:analysis_server/src/protocol/protocol_internal.dart';
 import 'package:analysis_server/src/protocol_server.dart' as protocol;
 import 'package:analysis_server/src/services/completion/dart/keyword_contributor.dart';

pkg/analysis_server/tool/instrumentation/log/log.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 /// A representation of the contents of an instrumentation log.
 import 'dart:convert';
 import 'dart:math' as math;

pkg/analysis_server/tool/instrumentation/log_viewer.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 import 'dart:io' as io;
 
 import 'package:args/args.dart';

pkg/analysis_server/tool/instrumentation/page/log_page.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 import 'dart:math' as math;
 
 import '../log/log.dart';

pkg/analysis_server/tool/instrumentation/page/page_writer.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 import 'dart:convert';
 
 import '../log/log.dart';

pkg/analysis_server/tool/instrumentation/page/stats_page.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 import '../log/log.dart';
 import 'page_writer.dart';
 

pkg/analysis_server/tool/instrumentation/server.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 import 'dart:collection';
 import 'dart:io';
 

pkg/analysis_server/tool/lsp_spec/codegen_dart.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 import 'package:dart_style/dart_style.dart';
 import 'package:meta/meta.dart';
 

pkg/analysis_server/tool/lsp_spec/generate_all.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 import 'dart:io';
 
 import 'package:analysis_server/src/utilities/strings.dart';
@@ -155,6 +157,8 @@ String generatedFileHeader(int year, {bool importCustom = false}) => '''
 // 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 = 2.9
+
 // This file has been automatically generated. Please do not edit it manually.
 // To regenerate the file, use the script
 // "pkg/analysis_server/tool/lsp_spec/generate_all.dart".

pkg/analysis_server/tool/lsp_spec/markdown.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 final _methodNamesPattern = RegExp(
     r'''_(?:Notification|Request):?_:?(?:\r?\n)+\* method: ['`](.*?)[`'],?\r?\n''',
     multiLine: true);

pkg/analysis_server/tool/lsp_spec/typescript.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 import 'typescript_parser.dart';
 
 /// Removes types that are in the spec that we don't want in other signatures.

pkg/analysis_server/tool/lsp_spec/typescript_parser.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 import 'dart:math';
 
 import 'package:analysis_server/src/utilities/strings.dart' show capitalize;

pkg/analysis_server/tool/migration_runner.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 /// This executable provides the ability to run the migration tool in process
 /// on a single package.  It should be invoked with two command-line arguments:
 /// a path to a configuration file and the name of a package to migrate.

pkg/analysis_server/tool/spec/api.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 /// Data structures representing an API definition, and visitor base classes
 /// for visiting those data structures.
 import 'dart:collection';

pkg/analysis_server/tool/spec/check_all_test.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 import 'dart:io';
 
 import 'package:analyzer_utilities/tools.dart';

pkg/analysis_server/tool/spec/codegen_analysis_server.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 /// Code generation for the file "AnalysisServer.java".
 import 'package:analyzer_utilities/tools.dart';
 

pkg/analysis_server/tool/spec/codegen_dart.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 import 'api.dart';
 
 /// Visitor specialized for generating Dart code.

pkg/analysis_server/tool/spec/codegen_dart_notification_handler.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 import 'package:analyzer_utilities/tools.dart';
 import 'package:html/dom.dart';
 
@@ -110,6 +112,8 @@ mixin NotificationHandler {
   void visitApi() {
     outputHeader(year: '2018');
     writeln();
+    writeln('// @dart = 2.9');
+    writeln();
     emitImports();
     emitNotificationHandler();
   }

pkg/analysis_server/tool/spec/codegen_dart_protocol.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 import 'dart:convert';
 
 import 'package:analyzer_utilities/tools.dart';
@@ -1120,6 +1122,8 @@ class CodegenProtocolVisitor extends DartCodegenVisitor with CodeGenerator {
   void visitApi() {
     outputHeader(year: '2017');
     writeln();
+    writeln('// @dart = 2.9');
+    writeln();
     emitImports();
     emitClasses(getClassesToEmit());
   }

pkg/analysis_server/tool/spec/codegen_inttest_methods.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 /// Code generation for the file "integration_test_methods.dart".
 import 'package:analyzer_utilities/tools.dart';
 import 'package:path/path.dart' as path;
@@ -84,6 +86,8 @@ class CodegenInttestMethodsVisitor extends DartCodegenVisitor
   void visitApi() {
     outputHeader(year: '2017');
     writeln();
+    writeln('// @dart = 2.9');
+    writeln();
     writeln('/// Convenience methods for running integration tests.');
     writeln("import 'dart:async';");
     writeln();

pkg/analysis_server/tool/spec/codegen_java.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 /// Tools for Java code generation.
 import 'package:analyzer_utilities/tools.dart';
 import 'package:html/dom.dart' as dom;

pkg/analysis_server/tool/spec/codegen_java_types.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 /// Code generation for the file "AnalysisServer.java".
 import 'package:analyzer_utilities/tools.dart';
 import 'package:html/dom.dart' as dom;

pkg/analysis_server/tool/spec/codegen_matchers.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 /// Code generation for the file "matchers.dart".
 import 'package:analyzer_utilities/tools.dart';
 
@@ -89,6 +91,8 @@ class CodegenMatchersVisitor extends HierarchicalApiVisitor with CodeGenerator {
   void visitApi() {
     outputHeader(year: '2017');
     writeln();
+    writeln('// @dart = 2.9');
+    writeln();
     writeln('/// Matchers for data types defined in the analysis server API.');
     writeln("import 'package:test/test.dart';");
     writeln();

pkg/analysis_server/tool/spec/codegen_protocol_constants.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 import 'package:analyzer_utilities/tools.dart';
 
 import 'api.dart';
@@ -88,6 +90,8 @@ class CodegenVisitor extends DartCodegenVisitor with CodeGenerator {
   void visitApi() {
     outputHeader(year: '2017');
     writeln();
+    writeln('// @dart = 2.9');
+    writeln();
     generateConstants();
   }
 }

pkg/analysis_server/tool/spec/from_html.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 /// Code for reading an HTML API description.
 import 'dart:io';
 

pkg/analysis_server/tool/spec/generate_all.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 import 'dart:io';
 
 import 'package:analyzer_utilities/tools.dart';

pkg/analysis_server/tool/spec/implied_types.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 /// Code for enumerating the set of types implied by the API.
 import 'package:analyzer_utilities/tools.dart';
 

pkg/analysis_server/tool/spec/to_html.dart

@@ -2,6 +2,8 @@
 // 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 = 2.9
+
 /// Code for displaying the API as HTML.  This is used both for generating a
 /// full description of the API as a web page, and for generating doc comments
 /// in generated code.