[dart2js] Migrate pkg/compiler/tool to null safety.

Change-Id: I800aa4b5af9b9950ece488ed7e59bf98d2fc1c1b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/282980
Reviewed-by: Sigmund Cherem <sigmund@google.com>

pkg/compiler/tool/dart2js_profile_many.dart

@@ -2,8 +2,6 @@
 // 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 = 2.10
-
 library dart2js.profile_many;
 
 import 'dart:async';
@@ -43,10 +41,10 @@ void main(List<String> args) {
   };
 
   Future.forEach(files, (String file) {
-    List subargs = [];
+    List<String> subargs = [];
     subargs.addAll(options);
     subargs.add(file);
-    return cmdline.compilerMain(subargs).catchError((e) {});
+    return cmdline.compilerMain(subargs);
   }).then((_) {
     print("Done");
   });

pkg/compiler/tool/dart2js_stress.dart

@@ -2,8 +2,6 @@
 // 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 = 2.10
-
 library dart2js.stress;
 
 import 'package:compiler/src/dart2js.dart' as dart2js;
@@ -13,7 +11,7 @@ const ITERATIONS_FLAG_PREFIX = "--iterations=";
 void main(List<String> args) {
   Stopwatch sw = new Stopwatch();
   int count = 0;
-  int maxCount = null;
+  int? maxCount = null;
   if (args.isNotEmpty && args[0].startsWith(ITERATIONS_FLAG_PREFIX)) {
     maxCount = int.parse(args[0].substring(ITERATIONS_FLAG_PREFIX.length));
     args = args.sublist(1);

pkg/compiler/tool/kernel_visitor/dart_html_metrics_visitor.dart

@@ -2,8 +2,6 @@
 // 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 = 2.10
-
 import "dart:convert";
 import "dart:io";
 import "package:kernel/kernel.dart";
@@ -29,13 +27,11 @@ main(List<String> args) async {
 /// Visits classes in libraries specified by `libraryFilter`
 /// and aggregates metrics by class.
 class MetricsVisitor extends RecursiveVisitor {
-  String currentClass;
+  late String currentClass;
   List<String> libraryFilter;
   Map<String, ClassMetrics> classInfo = {};
 
-  MetricsVisitor([filter]) {
-    libraryFilter = filter ?? [];
-  }
+  MetricsVisitor([List<String>? filter]) : libraryFilter = filter ?? [];
 
   @override
   void visitComponent(Component node) {
@@ -58,7 +54,7 @@ class MetricsVisitor extends RecursiveVisitor {
 
   @override
   void visitProcedure(Procedure node) {
-    classInfo[currentClass].methods.add(ClassMetricsMethod(
+    classInfo[currentClass]!.methods.add(ClassMetricsMethod(
         node.name.text,
         node.containsSuperCalls,
         node.isInstanceMember,
@@ -83,12 +79,12 @@ class MetricsVisitor extends RecursiveVisitor {
       // Check if Mixed.
       if (node.superclass?.isAnonymousMixin ?? false) {
         metrics.mixed = true;
-        metrics.mixins = _filterMixins(node.superclass.demangledName);
+        metrics.mixins = _filterMixins(node.superclass!.demangledName);
       }
 
       // Add parents.
       if (node.superclass != null) {
-        var unmangledParent = _getParent(node.superclass);
+        var unmangledParent = _getParent(node.superclass!);
         metrics.parent = unmangledParent;
       }
 
@@ -118,7 +114,7 @@ class MetricsVisitor extends RecursiveVisitor {
   // and returns parent class name.
   String _getParent(Class node) {
     if (node.isAnonymousMixin) {
-      return _getParent(node.superclass);
+      return _getParent(node.superclass!);
     }
 
     return node.name;
@@ -139,19 +135,19 @@ class MetricsVisitor extends RecursiveVisitor {
   // adding child classes and overridden methods from parent.
   void _processData() {
     classInfo.keys.forEach((className) {
-      var parentName = classInfo[className].parent;
+      var parentName = classInfo[className]!.parent;
       if (classInfo[parentName] != null) {
-        classInfo[parentName].inheritedBy.add(className);
+        classInfo[parentName]!.inheritedBy.add(className);
 
         var notOverridden = <String>[];
-        var parentMethods = classInfo[parentName].methods.map((m) => m.name);
-        var classMethods = classInfo[className].methods.map((m) => m.name);
+        var parentMethods = classInfo[parentName]!.methods.map((m) => m.name);
+        var classMethods = classInfo[className]!.methods.map((m) => m.name);
 
         parentMethods.forEach((method) =>
             {if (!classMethods.contains(method)) notOverridden.add(method)});
 
         // Update Method Info.
-        classInfo[className].notOverriddenMethods = notOverridden;
+        classInfo[className]!.notOverriddenMethods = notOverridden;
       }
     });
   }
@@ -177,7 +173,7 @@ class ClassMetrics {
   List<String> implementedTypes;
   List<String> notOverriddenMethods;
   List<String> inheritedBy;
-  String parent;
+  String? parent;
   bool mixed;
   bool containsNativeMember;
 
@@ -185,17 +181,16 @@ class ClassMetrics {
       {this.mixed = false,
       this.containsNativeMember = false,
       this.parent,
-      methods,
-      mixins,
-      notOverridden,
-      implementedTypes,
-      inheritedBy}) {
-    this.methods = methods ?? [];
-    this.mixins = mixins ?? [];
-    this.notOverriddenMethods = notOverridden ?? [];
-    this.implementedTypes = implementedTypes ?? [];
-    this.inheritedBy = inheritedBy ?? [];
-  }
+      List<ClassMetricsMethod>? methods,
+      List<String>? mixins,
+      List<String>? notOverridden,
+      List<String>? implementedTypes,
+      List<String>? inheritedBy})
+      : this.methods = methods ?? [],
+        this.mixins = mixins ?? [],
+        this.notOverriddenMethods = notOverridden ?? [],
+        this.implementedTypes = implementedTypes ?? [],
+        this.inheritedBy = inheritedBy ?? [];
 
   bool get invokesSuper {
     if (methods.isNotEmpty) {

pkg/compiler/tool/kernel_visitor/test/info_visitor_test.dart

@@ -2,8 +2,6 @@
 // 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 = 2.10
-
 import "dart:io";
 
 import "package:expect/expect.dart";
@@ -16,58 +14,59 @@ import "../dart_html_metrics_visitor.dart";
 
 void runTests(MetricsVisitor visitor) {
   test("Class A does not call super", () {
-    Expect.equals(visitor.classInfo["A"].invokesSuper, false);
+    Expect.equals(visitor.classInfo["A"]!.invokesSuper, false);
   });
 
   test("Class B does call super", () {
-    Expect.equals(visitor.classInfo["B"].invokesSuper, true);
+    Expect.equals(visitor.classInfo["B"]!.invokesSuper, true);
 
-    var callingMethod = visitor.classInfo["B"].methods
+    var callingMethod = visitor.classInfo["B"]!.methods
         .where((m) => m.name == "testSuper")
         .toList()[0];
     Expect.equals(callingMethod.invokesSuper, true);
   });
 
   test("Class C does not call super", () {
-    Expect.equals(visitor.classInfo["C"].invokesSuper, false);
+    Expect.equals(visitor.classInfo["C"]!.invokesSuper, false);
   });
 
   test("Class A inherited by B", () {
-    Expect.equals(visitor.classInfo["A"].inheritedBy.contains("B"), true);
-    Expect.equals(visitor.classInfo["B"].parent, "A");
+    Expect.equals(visitor.classInfo["A"]!.inheritedBy.contains("B"), true);
+    Expect.equals(visitor.classInfo["B"]!.parent, "A");
   });
 
   test("Class B inherited by C", () {
-    Expect.equals(visitor.classInfo["B"].inheritedBy.contains("C"), true);
-    Expect.equals(visitor.classInfo["C"].parent, "B");
+    Expect.equals(visitor.classInfo["B"]!.inheritedBy.contains("C"), true);
+    Expect.equals(visitor.classInfo["C"]!.parent, "B");
   });
 
   test("Class B inherited by F", () {
-    Expect.equals(visitor.classInfo["B"].inheritedBy.contains("F"), true);
-    Expect.equals(visitor.classInfo["F"].parent, "B");
+    Expect.equals(visitor.classInfo["B"]!.inheritedBy.contains("F"), true);
+    Expect.equals(visitor.classInfo["F"]!.parent, "B");
   });
 
   test("Class C inherited by nothing", () {
-    Expect.equals(visitor.classInfo["C"].inheritedBy.length, 0);
+    Expect.equals(visitor.classInfo["C"]!.inheritedBy.length, 0);
   });
 
   test("Class D mixed with Mix1 and Mix2", () {
-    Expect.equals(visitor.classInfo["D"].mixed, true);
-    Expect.deepEquals(visitor.classInfo["D"].mixins, ["Mix1", "Mix2"]);
+    Expect.equals(visitor.classInfo["D"]!.mixed, true);
+    Expect.deepEquals(visitor.classInfo["D"]!.mixins, ["Mix1", "Mix2"]);
   });
 
   test("Class F mixed with Mix1 and Mix2", () {
-    Expect.equals(visitor.classInfo["F"].mixed, true);
-    Expect.deepEquals(visitor.classInfo["F"].mixins, ["Mix1", "Mix2"]);
+    Expect.equals(visitor.classInfo["F"]!.mixed, true);
+    Expect.deepEquals(visitor.classInfo["F"]!.mixins, ["Mix1", "Mix2"]);
   });
 
   test("Class E implements A", () {
-    Expect.equals(visitor.classInfo["E"].implementedTypes.contains("A"), true);
+    Expect.equals(visitor.classInfo["E"]!.implementedTypes.contains("A"), true);
   });
 
   test("Class G extends A but fails to override getValue()", () {
     Expect.equals(
-        visitor.classInfo["G"].notOverriddenMethods.contains("getValue"), true);
+        visitor.classInfo["G"]!.notOverriddenMethods.contains("getValue"),
+        true);
   });
 }
 

pkg/compiler/tool/modular_dart2js.dart

@@ -2,21 +2,19 @@
 // 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 = 2.10
-
 import 'dart:convert';
 import 'dart:io';
 import 'package:compiler/src/commandline_options.dart';
 
 main(List<String> args) async {
   Stopwatch stopwatch = new Stopwatch();
-  String input;
-  String serializedInput;
+  String? input;
+  String? serializedInput;
   String output = 'out.js';
   List<String> arguments = [];
   int start = 0;
   int stop = 3;
-  int shards;
+  int? shards;
   bool enableAssertions = false;
   for (String arg in args) {
     if (arg.startsWith('-')) {

pkg/compiler/tool/modular_test_suite.dart

@@ -2,8 +2,6 @@
 // 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 = 2.10
-
 /// Test the modular compilation pipeline of dart2js.
 ///
 /// This is a shell that runs multiple tests, one per folder under `data/`.

pkg/compiler/tool/modular_test_suite_helper.dart

@@ -2,8 +2,6 @@
 // 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 = 2.10
-
 /// Test the modular compilation pipeline of dart2js.
 ///
 /// This is a shell that runs multiple tests, one per folder under `data/`.
@@ -23,9 +21,9 @@ import 'package:modular_test/src/suite.dart';
 String packageConfigJsonPath = ".dart_tool/package_config.json";
 Uri sdkRoot = Platform.script.resolve("../../../");
 Uri packageConfigUri = sdkRoot.resolve(packageConfigJsonPath);
-Options _options;
-String _dart2jsScript;
-String _kernelWorkerScript;
+late Options _options;
+late String _dart2jsScript;
+late String _kernelWorkerScript;
 
 const dillSummaryId = DataId("summary.dill");
 const dillId = DataId("full.dill");
@@ -57,7 +55,7 @@ String getRootScheme(Module module) {
 
 String sourceToImportUri(Module module, Uri relativeUri) {
   if (module.isPackage) {
-    var basePath = module.packageBase.path;
+    var basePath = module.packageBase!.path;
     var packageRelativePath = basePath == "./"
         ? relativeUri.path
         : relativeUri.path.substring(basePath.length);
@@ -112,7 +110,7 @@ abstract class CFEStep extends IOModularStep {
         await File.fromUri(platform).copy(destination.toFilePath());
         return;
       }
-      sources = requiredLibraries['dart2js'] + ['dart:core'];
+      sources = requiredLibraries['dart2js']! + ['dart:core'];
       extraArgs += [
         '--libraries-file',
         '$rootScheme:///sdk/lib/libraries.json'
@@ -331,7 +329,7 @@ class ConcatenateDillsStep extends IOModularStep {
   @override
   bool get onlyOnMain => true;
 
-  ConcatenateDillsStep({this.useModularAnalysis});
+  ConcatenateDillsStep({required this.useModularAnalysis});
 
   @override
   Future<void> execute(Module module, Uri root, ModuleDataToRelativeUri toUri,
@@ -380,7 +378,7 @@ class ConcatenateDillsStep extends IOModularStep {
 class ComputeClosedWorldStep extends IOModularStep {
   final bool useModularAnalysis;
 
-  ComputeClosedWorldStep({this.useModularAnalysis});
+  ComputeClosedWorldStep({required this.useModularAnalysis});
 
   List<DataId> get dependencies => [
         fullDillId,

pkg/compiler/tool/modular_test_suite_legacy.dart

@@ -2,8 +2,6 @@
 // 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 = 2.10
-
 /// Test the modular compilation pipeline of dart2js.
 ///
 /// This is a shell that runs multiple tests, one per folder under `data/`.

pkg/compiler/tool/track_memory.dart

@@ -2,8 +2,6 @@
 // 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 = 2.10
-
 // ignore_for_file: avoid_dynamic_calls
 
 /// A script to track the high water-mark of memory usage of an application.
@@ -21,7 +19,7 @@ import 'dart:async';
 import 'dart:convert';
 
 /// Socket to connect to the vm observatory service.
-WebSocket socket;
+late WebSocket socket;
 
 main(args) async {
   _printHeader();
@@ -80,8 +78,8 @@ Future _sendMessage(String method, [Map args = const {}]) {
 }
 
 /// Handle all responses
-void _handleResponse(Object s) {
-  var json = jsonDecode(s);
+void _handleResponse(Object? s) {
+  var json = jsonDecode(s as String);
   if (json['method'] != 'streamNotify') {
     var id = json['id'];
     if (id is String) id = int.parse(id);
@@ -177,7 +175,7 @@ _writeNumber(sb, before, now, {color = false}) {
         : before > now
             ? _GREEN
             : '');
-  var string;
+  String string;
   if (now < 1024) {
     string = ' ${now}b';
   } else if (now < mega) {

pkg/compiler/tool/update_id_tests.dart

@@ -2,8 +2,6 @@
 // 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 = 2.10
-
 import 'package:_fe_analyzer_shared/src/testing/id_testing.dart' as id;
 
 const List<String> idTests = <String>[