Add support for --strong option in the engine, create a strong mode version of...

Add support for --strong option in the engine, create a strong mode version of the platform file (#4504)

* Add a --strong option to the front end server so we can use strong mode with preview-dart-2.

* Plumb the --strong option through the dart controller into the VM.

* - Build a strong version of platform.dill for use with the engine.
- Fix a strong mode static error in the assert statement

* Enable asserts when running debug version even in strong mode.

* Use the correct platform dill file for linking when doing the aot builds.

* Fix formatting issue.

BUILD.gn

@@ -6,7 +6,7 @@ group("flutter") {
   testonly = true
 
   public_deps = [
-    "$flutter_root/lib/snapshot:compile_platform",
+    "$flutter_root/lib/snapshot:kernel_platform_files",
     "$flutter_root/lib/snapshot:generate_snapshot_bin",
     "$flutter_root/sky",
     "$flutter_root/third_party/txt",

common/settings.h

@@ -24,6 +24,7 @@ struct Settings {
   bool enable_dart_profiling = false;
   bool use_test_fonts = false;
   bool dart_non_checked_mode = false;
+  bool dart_strong_mode = false;
   bool enable_software_rendering = false;
   bool using_blink = true;
   std::string aot_shared_library_path;

frontend_server/lib/server.dart

@@ -39,6 +39,9 @@ ArgParser _argParser = new ArgParser(allowTrailingOptions: true)
   ..addFlag('aot',
       help: 'Run compiler in AOT mode (enables whole-program transformations)',
       defaultsTo: false)
+  ..addFlag('strong',
+      help: 'Run compiler in strong mode (uses strong mode semantics)',
+      defaultsTo: false)
   ..addFlag('link-platform',
       help:
           'When in batch mode, link platform kernel file into result kernel file.'
@@ -147,8 +150,8 @@ class _FrontendCompiler implements CompilerInterface {
           ? new FileByteStore(byteStorePath)
           : new MemoryByteStore()
       ..sdkRoot = sdkRoot
-      ..strongMode = false
-      ..target = new FlutterTarget(new TargetFlags())
+      ..strongMode = options['strong']
+      ..target = new FlutterTarget(new TargetFlags(strongMode: options['strong']))
       ..reportMessages = true;
 
     Program program;
@@ -165,8 +168,10 @@ class _FrontendCompiler implements CompilerInterface {
       if (options['link-platform']) {
         // TODO(aam): Remove linkedDependencies once platform is directly embedded
         // into VM snapshot and http://dartbug.com/30111 is fixed.
+        final String platformKernelDill =
+            options['strong'] ? 'platform_strong.dill' : 'platform.dill';
         compilerOptions.linkedDependencies = <Uri>[
-          sdkRoot.resolve('platform.dill')
+          sdkRoot.resolve(platformKernelDill)
         ];
       }
       program = await _runWithPrintRedirection(() =>

frontend_server/test/server_test.dart

@@ -51,6 +51,28 @@ Future<int> main() async {
           )
         ).captured;
       expect(capturedArgs.single['sdk-root'], equals('sdkroot'));
+      expect(capturedArgs.single['strong'], equals(false));
+    });
+
+    test('compile from command line (strong mode)', () async {
+      final List<String> args = <String>[
+        'server.dart',
+        '--sdk-root',
+        'sdkroot',
+        '--strong',
+      ];
+      final int exitcode = await starter(args, compiler: compiler);
+      expect(exitcode, equals(0));
+      final List<ArgResults> capturedArgs =
+        verify(
+          compiler.compile(
+            argThat(equals('server.dart')),
+            captureAny,
+            generator: any,
+          )
+        ).captured;
+      expect(capturedArgs.single['sdk-root'], equals('sdkroot'));
+      expect(capturedArgs.single['strong'], equals(true));
     });
 
     test('compile from command line with file byte store', () async {
@@ -73,6 +95,7 @@ Future<int> main() async {
           ).captured;
       expect(capturedArgs.single['sdk-root'], equals('sdkroot'));
       expect(capturedArgs.single['byte-store'], equals('path/to/bytestore'));
+      expect(capturedArgs.single['strong'], equals(false));
     });
 
     test('compile from command line with link platform', () async {
@@ -94,6 +117,7 @@ Future<int> main() async {
           ).captured;
       expect(capturedArgs.single['sdk-root'], equals('sdkroot'));
       expect(capturedArgs.single['link-platform'], equals(true));
+      expect(capturedArgs.single['strong'], equals(false));
     });
   });
 
@@ -118,6 +142,7 @@ Future<int> main() async {
                 equals('sdkroot'));
             expect(invocation.positionalArguments[1]['byte-store'],
                 equals('path/to/bytestore'));
+            expect(invocation.positionalArguments[1]['strong'], equals(false));
             compileCalled.sendPort.send(true);
           }
       );
@@ -139,6 +164,11 @@ Future<int> main() async {
       '--sdk-root',
       'sdkroot',
     ];
+    final List<String> strongArgs = <String>[
+      '--sdk-root',
+      'sdkroot',
+      '--strong',
+    ];
 
     test('compile one file', () async {
       final StreamController<List<int>> inputStreamController =
@@ -148,6 +178,7 @@ Future<int> main() async {
         (Invocation invocation) {
           expect(invocation.positionalArguments[0], equals('server.dart'));
           expect(invocation.positionalArguments[1]['sdk-root'], equals('sdkroot'));
+          expect(invocation.positionalArguments[1]['strong'], equals(false));
           compileCalled.sendPort.send(true);
         }
       );
@@ -160,6 +191,28 @@ Future<int> main() async {
       await compileCalled.first;
       inputStreamController.close();
     });
+    
+    test('compile one file (strong mode)', () async {
+      final StreamController<List<int>> inputStreamController =
+        new StreamController<List<int>>();
+      final ReceivePort compileCalled = new ReceivePort();
+      when(compiler.compile(any, any, generator: any)).thenAnswer(
+        (Invocation invocation) {
+          expect(invocation.positionalArguments[0], equals('server.dart'));
+          expect(invocation.positionalArguments[1]['sdk-root'], equals('sdkroot'));
+          expect(invocation.positionalArguments[1]['strong'], equals(true));
+          compileCalled.sendPort.send(true);
+        }
+      );
+
+      final int exitcode = await starter(strongArgs, compiler: compiler,
+        input: inputStreamController.stream,
+      );
+      expect(exitcode, equals(0));
+      inputStreamController.add('compile server.dart\n'.codeUnits);
+      await compileCalled.first;
+      inputStreamController.close();
+    });
 
     test('compile few files', () async {
       final StreamController<List<int>> streamController =
@@ -170,6 +223,7 @@ Future<int> main() async {
         (Invocation invocation) {
           expect(invocation.positionalArguments[0], equals('server${counter++}.dart'));
           expect(invocation.positionalArguments[1]['sdk-root'], equals('sdkroot'));
+          expect(invocation.positionalArguments[1]['strong'], equals(false));
           compileCalled.sendPort.send(true);
         }
       );

lib/snapshot/BUILD.gn

@@ -396,9 +396,13 @@ generate_vm_patched_sdk("flutter_patched_sdk") {
   ]
 }
 
-action("compile_platform") {
+action("compile_non_strong_platform") {
   script = "//third_party/dart/tools/compile_platform.py"
 
+  visibility = [
+    ":kernel_platform_files"
+  ]
+
   sources = [
     "$root_out_dir/flutter_patched_sdk/lib/libraries.json",
   ]
@@ -423,8 +427,41 @@ action("compile_platform") {
          rebase_path(outputs, root_build_dir)
 }
 
+action("compile_platform") {
+  script = "//third_party/dart/tools/compile_platform.py"
+
+  visibility = [
+    ":kernel_platform_files"
+  ]
+  
+  sources = [
+    "$root_out_dir/flutter_patched_sdk/lib/libraries.json",
+  ]
+
+  outputs = [
+    "$root_out_dir/flutter_patched_sdk/platform_strong.dill",
+    "$root_out_dir/flutter_patched_sdk/vm_outline_strong.dill",
+  ]
+
+  inputs = []
+
+  deps = [
+    ":flutter_patched_sdk",
+  ]
+
+  depfile = "$root_out_dir/flutter_patched_sdk/platform_strong.dill.d"
+
+  args = [
+            "--target=flutter",
+            "--strong",
+            "dart:core"
+         ] + rebase_path(sources, root_build_dir) +
+         rebase_path(outputs, root_build_dir)
+}
+
 group("kernel_platform_files") {
   public_deps = [
     ":compile_platform",
+    ":compile_non_strong_platform",
   ]
 }

lib/ui/natives.dart

@@ -32,7 +32,7 @@ void _setupHooks() {
     // In debug mode, register the schedule frame extension.
     developer.registerExtension('ext.ui.window.scheduleFrame', _scheduleFrame);
     return true;
-  });
+  }());
 }
 
 void _scheduleMicrotask(void callback()) native "ScheduleMicrotask";

runtime/dart_init.cc

@@ -104,15 +104,28 @@ static const char* kDartWriteProtectCodeArgs[] FXL_ALLOW_UNUSED_TYPE = {
     "--no_write_protect_code",
 };
 
-static const char* kDartCheckedModeArgs[] = {
+static const char* kDartAssertArgs[] = {
     // clang-format off
     "--enable_asserts",
+    // clang-format on
+};
+
+static const char* kDartCheckedModeArgs[] = {
+    // clang-format off
     "--enable_type_checks",
     "--error_on_bad_type",
     "--error_on_bad_override",
     // clang-format on
 };
 
+static const char* kDartStrongModeArgs[] = {
+    // clang-format off
+    "--strong",
+    "--reify_generic_functions",
+    "--limit_ints_to_64_bits",
+    // clang-format on
+};
+
 static const char* kDartStartPausedArgs[]{
     "--pause_isolates_on_start",
 };
@@ -584,8 +597,17 @@ void InitDartVM(const uint8_t* vm_snapshot_data,
               arraysize(kDartWriteProtectCodeArgs));
 #endif
 
-  if (use_checked_mode)
+  if (settings.dart_strong_mode) {
+    // In strong mode we enable all the strong mode options and if running
+    // debug product mode we also enable asserts.
+    PushBackAll(&args, kDartStrongModeArgs, arraysize(kDartStrongModeArgs));
+    if (use_checked_mode) {
+      PushBackAll(&args, kDartAssertArgs, arraysize(kDartAssertArgs));
+    }
+  } else if (use_checked_mode) {
+    PushBackAll(&args, kDartAssertArgs, arraysize(kDartAssertArgs));
     PushBackAll(&args, kDartCheckedModeArgs, arraysize(kDartCheckedModeArgs));
+  }
 
   if (settings.start_paused)
     PushBackAll(&args, kDartStartPausedArgs, arraysize(kDartStartPausedArgs));

shell/common/shell.cc

@@ -107,6 +107,10 @@ void Shell::InitStandalone(fxl::CommandLine command_line,
   settings.dart_non_checked_mode =
       command_line.HasOption(FlagForSwitch(Switch::DartNonCheckedMode));
 
+  // strong mode setting.
+  settings.dart_strong_mode =
+      command_line.HasOption(FlagForSwitch(Switch::DartStrongMode));
+
   settings.ipv6 = command_line.HasOption(FlagForSwitch(Switch::IPv6));
 
   settings.start_paused =

shell/common/switches.h

@@ -104,6 +104,7 @@ DEF_SWITCH(DartNonCheckedMode,
            "precompiled and checked mode is unsupported. However, this flag "
            "may be specified if the user wishes to run in the debug product "
            "mode (i.e. with JIT or DBC) with checked mode off.")
+DEF_SWITCH(DartStrongMode, "strong", "Enable Dart 2.0 strong mode.")
 DEF_SWITCHES_END
 
 void PrintUsage(const std::string& executable_name);

shell/platform/android/io/flutter/app/FlutterActivityDelegate.java

@@ -301,6 +301,9 @@ public final class FlutterActivityDelegate
         if (intent.getBooleanExtra("trace-skia", false)) {
             args.add("--trace-skia");
         }
+        if (intent.getBooleanExtra("strong", false)) {
+            args.add("--strong");
+        }
         if (!args.isEmpty()) {
             String[] argsArray = new String[args.size()];
             return args.toArray(argsArray);