Enable code generation features in tool (#29399)

dev/devicelab/manifest.yaml

@@ -82,7 +82,6 @@ tasks:
       correctly.
     stage: devicelab_win
     required_agent_capabilities: ["windows/android"]
-    flaky: true
 
   codegen_integration_mac:
     description: >
@@ -90,7 +89,6 @@ tasks:
       correctly.
     stage: devicelab_ios
     required_agent_capabilities: ["mac/ios"]
-    flaky: true
 
   codegen_integration_linux:
     description: >
@@ -98,7 +96,6 @@ tasks:
       correctly.
     stage: devicelab
     required_agent_capabilities: ["linux/android"]
-    flaky: true
 
   flutter_gallery_android__compile:
     description: >

packages/flutter_tools/lib/executable.dart

@@ -95,6 +95,6 @@ Future<void> main(List<String> args) async {
      overrides: <Type, Generator>{
        // The build runner instance is not supported in google3 because
        // the build runner packages are not synced internally.
-       CodeGenerator: () => experimentalBuildEnabled ? const BuildRunner() : const UnsupportedCodeGenerator(),
+       CodeGenerator: () => const BuildRunner(),
      });
 }

packages/flutter_tools/lib/src/base/build.dart

@@ -188,7 +188,7 @@ class AOTSnapshotter {
         'sharedLib': buildSharedLibrary.toString(),
         'extraGenSnapshotOptions': extraGenSnapshotOptions.join(' '),
         'engineHash': engine.version,
-        'buildersUsed': '${flutterProject != null ? await flutterProject.hasBuilders : false}',
+        'buildersUsed': '${flutterProject != null ? flutterProject.hasBuilders : false}',
       },
       depfilePaths: <String>[],
     );
@@ -299,6 +299,7 @@ class AOTSnapshotter {
     @required bool trackWidgetCreation,
     List<String> extraFrontEndOptions = const <String>[],
   }) async {
+    final FlutterProject flutterProject = await FlutterProject.current();
     final Directory outputDir = fs.directory(outputPath);
     outputDir.createSync(recursive: true);
 
@@ -308,6 +309,7 @@ class AOTSnapshotter {
       printTrace('Extra front-end options: $extraFrontEndOptions');
 
     final String depfilePath = fs.path.join(outputPath, 'kernel_compile.d');
+    final KernelCompiler kernelCompiler = await kernelCompilerFactory.create(flutterProject);
     final CompilerOutput compilerOutput = await kernelCompiler.compile(
       sdkRoot: artifacts.getArtifactPath(Artifact.flutterPatchedSdkPath),
       mainPath: mainPath,

packages/flutter_tools/lib/src/build_runner/build_runner.dart

@@ -48,7 +48,7 @@ class BuildRunner extends CodeGenerator {
 
     // Check if contents of builders changed. If so, invalidate build script
     // and regnerate.
-    final YamlMap builders = await flutterProject.builders;
+    final YamlMap builders = flutterProject.builders;
     final List<int> appliedBuilderDigest = _produceScriptId(builders);
     if (scriptIdFile.existsSync() && buildSnapshot.existsSync()) {
       final List<int> previousAppliedBuilderDigest = scriptIdFile.readAsBytesSync();
@@ -79,7 +79,7 @@ class BuildRunner extends CodeGenerator {
 
       stringBuffer.writeln('name: flutter_tool');
       stringBuffer.writeln('dependencies:');
-      final YamlMap builders = await flutterProject.builders;
+      final YamlMap builders = flutterProject.builders;
       if (builders != null) {
         for (String name in builders.keys) {
           final Object node = builders[name];
@@ -147,6 +147,7 @@ class BuildRunner extends CodeGenerator {
         buildSnapshot.path,
         'daemon',
          '--skip-build-script-check',
+         '--delete-conflicting-outputs'
       ];
       buildDaemonClient = await BuildDaemonClient.connect(flutterProject.directory.path, command, logHandler: (ServerLog log) => printTrace(log.toString()));
     } finally {

packages/flutter_tools/lib/src/build_runner/build_script_generator.dart

@@ -138,7 +138,11 @@ class BuildScriptGenerator {
     if (definition.isOptional) {
       namedArgs['isOptional'] = literalTrue;
     }
+    if (definition.buildTo == BuildTo.cache) {
       namedArgs['hideOutput'] = literalTrue;
+    } else {
+      namedArgs['hideOutput'] = literalFalse;
+    }
     if (!identical(definition.defaults?.generateFor, InputSet.anything)) {
       final Map<String, Expression> inputSetArgs = <String, Expression>{};
       if (definition.defaults.generateFor.include != null) {

packages/flutter_tools/lib/src/bundle.dart

@@ -16,6 +16,7 @@ import 'compile.dart';
 import 'dart/package_map.dart';
 import 'devfs.dart';
 import 'globals.dart';
+import 'project.dart';
 
 const String defaultMainPath = 'lib/main.dart';
 const String defaultAssetBasePath = '.';
@@ -72,6 +73,7 @@ Future<void> build({
   assetDirPath ??= getAssetBuildDirectory();
   packagesPath ??= fs.path.absolute(PackageMap.globalPackagesPath);
   applicationKernelFilePath ??= getDefaultApplicationKernelPath(trackWidgetCreation: trackWidgetCreation);
+  final FlutterProject flutterProject = await FlutterProject.current();
 
   if (compilationTraceFilePath != null) {
     if (buildMode != BuildMode.dynamicProfile && buildMode != BuildMode.dynamicRelease) {
@@ -99,6 +101,7 @@ Future<void> build({
     if ((extraFrontEndOptions != null) && extraFrontEndOptions.isNotEmpty)
       printTrace('Extra front-end options: $extraFrontEndOptions');
     ensureDirectoryExists(applicationKernelFilePath);
+    final KernelCompiler kernelCompiler = await kernelCompilerFactory.create(flutterProject);
     final CompilerOutput compilerOutput = await kernelCompiler.compile(
       sdkRoot: artifacts.getArtifactPath(Artifact.flutterPatchedSdkPath),
       incrementalCompilerByteStorePath: compilationTraceFilePath != null ? null :

packages/flutter_tools/lib/src/codegen.dart

@@ -25,21 +25,6 @@ const String kMultiRootScheme = 'org-dartlang-app';
 /// implementation.
 CodeGenerator get codeGenerator => context[CodeGenerator];
 
-/// Whether to attempt to build a flutter project using build* libraries.
-///
-/// This requires both an experimental opt in via the environment variable
-/// 'FLUTTER_EXPERIMENTAL_BUILD' and that the project itself has a
-/// dependency on the package 'flutter_build' and 'build_runner.'
-bool get experimentalBuildEnabled {
-  return _experimentalBuildEnabled ??= platform.environment['FLUTTER_EXPERIMENTAL_BUILD']?.toLowerCase() == 'true';
-}
-bool _experimentalBuildEnabled;
-
-@visibleForTesting
-set experimentalBuildEnabled(bool value) {
-  _experimentalBuildEnabled = value;
-}
-
 /// A wrapper for a build_runner process which delegates to a generated
 /// build script.
 ///

packages/flutter_tools/lib/src/commands/generate.dart

@@ -24,9 +24,6 @@ class GenerateCommand extends FlutterCommand {
   @override
   Future<FlutterCommandResult> runCommand() async {
     Cache.releaseLockEarly();
-    if (!experimentalBuildEnabled) {
-      throwToolExit('FLUTTER_EXPERIMENTAL_BUILD is not enabled, codegen is unsupported.');
-    }
     final FlutterProject flutterProject = await FlutterProject.current();
     final CodegenDaemon codegenDaemon = await codeGenerator.daemon(flutterProject);
     codegenDaemon.startBuild();

packages/flutter_tools/lib/src/commands/test.dart

@@ -160,7 +160,7 @@ class TestCommand extends FastFlutterCommand {
     Cache.releaseLockEarly();
 
     // Run builders once before all tests.
-    if (experimentalBuildEnabled && await flutterProject.hasBuilders) {
+    if (flutterProject.hasBuilders) {
       final CodegenDaemon codegenDaemon = await codeGenerator.daemon(flutterProject);
       codegenDaemon.startBuild();
       await for (CodegenStatus status in codegenDaemon.buildResults) {

packages/flutter_tools/lib/src/compile.dart

@@ -17,12 +17,24 @@ import 'base/platform.dart';
 import 'base/process_manager.dart';
 import 'base/terminal.dart';
 import 'cache.dart';
+import 'codegen.dart';
 import 'convert.dart';
 import 'dart/package_map.dart';
 import 'globals.dart';
 import 'project.dart';
 
-KernelCompiler get kernelCompiler => context[KernelCompiler];
+KernelCompilerFactory get kernelCompilerFactory => context[KernelCompilerFactory];
+
+class KernelCompilerFactory {
+  const KernelCompilerFactory();
+
+  Future<KernelCompiler> create(FlutterProject flutterProject) async {
+    if (flutterProject == null || !flutterProject.hasBuilders) {
+      return const KernelCompiler();
+    }
+    return const CodeGeneratingKernelCompiler();
+  }
+}
 
 typedef CompilerMessageConsumer = void Function(String message, { bool emphasis, TerminalColor color });
 
@@ -235,7 +247,7 @@ class KernelCompiler {
           'trackWidgetCreation': trackWidgetCreation.toString(),
           'linkPlatformKernelIn': linkPlatformKernelIn.toString(),
           'engineHash': engine.version,
-          'buildersUsed': '${flutterProject != null ? await flutterProject.hasBuilders : false}',
+          'buildersUsed': '${flutterProject != null ? flutterProject.hasBuilders : false}',
         },
         depfilePaths: <String>[depFilePath],
         pathFilter: (String path) => !path.startsWith('/b/build/slave/'),

packages/flutter_tools/lib/src/context_runner.dart

@@ -22,7 +22,6 @@ import 'base/time.dart';
 import 'base/user_messages.dart';
 import 'base/utils.dart';
 import 'cache.dart';
-import 'codegen.dart';
 import 'compile.dart';
 import 'devfs.dart';
 import 'device.dart';
@@ -83,7 +82,7 @@ Future<T> runInContext<T>(
       IOSSimulatorUtils: () => IOSSimulatorUtils(),
       IOSWorkflow: () => const IOSWorkflow(),
       IOSValidator: () => const IOSValidator(),
-      KernelCompiler: () => experimentalBuildEnabled ? const CodeGeneratingKernelCompiler() : const KernelCompiler(),
+      KernelCompilerFactory: () => const KernelCompilerFactory(),
       LinuxWorkflow: () => const LinuxWorkflow(),
       Logger: () => platform.isWindows ? WindowsStdoutLogger() : StdoutLogger(),
       MacOSWorkflow: () => const MacOSWorkflow(),

packages/flutter_tools/lib/src/project.dart

@@ -162,14 +162,17 @@ class FlutterProject {
   }
 
   /// Return the set of builders used by this package.
-  Future<YamlMap> get builders async {
-    final YamlMap pubspec = loadYaml(await pubspecFile.readAsString());
+  YamlMap get builders {
+    if (!pubspecFile.existsSync()) {
+      return null;
+    }
+    final YamlMap pubspec = loadYaml(pubspecFile.readAsStringSync());
     return pubspec['builders'];
   }
 
   /// Whether there are any builders used by this package.
-  Future<bool> get hasBuilders async {
-    final YamlMap result = await builders;
+  bool get hasBuilders {
+    final YamlMap result = builders;
     return result != null && result.isNotEmpty;
   }
 }

packages/flutter_tools/lib/src/resident_runner.dart

@@ -61,7 +61,7 @@ class FlutterDevice {
   }) async {
     ResidentCompiler generator;
     final FlutterProject flutterProject = await FlutterProject.current();
-    if (experimentalBuildEnabled && await flutterProject.hasBuilders) {
+    if (flutterProject.hasBuilders) {
       generator = await CodeGeneratingResidentCompiler.create(
         flutterProject: flutterProject,
       );

packages/flutter_tools/lib/src/test/flutter_platform.dart

@@ -270,7 +270,7 @@ class _Compiler {
     );
 
     Future<ResidentCompiler> createCompiler() async {
-      if (experimentalBuildEnabled && await flutterProject.hasBuilders) {
+      if (flutterProject.hasBuilders) {
         return CodeGeneratingResidentCompiler.create(
           flutterProject: flutterProject,
           trackWidgetCreation: trackWidgetCreation,

packages/flutter_tools/test/build_runner/build_runner_test.dart

-// Copyright 2019 The Chromium Authors. 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:flutter_tools/src/base/platform.dart';
-import 'package:flutter_tools/src/codegen.dart';
-import 'package:mockito/mockito.dart';
-
-import '../src/common.dart';
-import '../src/context.dart';
-
-void main() {
-  group('experimentalBuildEnabled', () {
-    final MockPlatform mockPlatform = MockPlatform();
-
-    setUp(() {
-      experimentalBuildEnabled = null;
-    });
-    testUsingContext('is enabled if environment variable is enabled', () async {
-      when(mockPlatform.environment).thenReturn(<String, String>{'FLUTTER_EXPERIMENTAL_BUILD': 'true'});
-      expect(experimentalBuildEnabled, true);
-    }, overrides: <Type, Generator>{
-      Platform: () => mockPlatform,
-    });
-
-    testUsingContext('is not enabed if environment varable is not enabled', () async {
-      when(mockPlatform.environment).thenReturn(<String, String>{});
-      expect(experimentalBuildEnabled, false);
-    }, overrides: <Type, Generator>{
-      Platform: () => mockPlatform,
-    });
-  });
-}
-
-class MockPlatform extends Mock implements Platform {}

packages/flutter_tools/test/compile_test.dart

@@ -121,6 +121,7 @@ example:org-dartlang-app:/
               'result abc\nline1\nline2\nabc\nabc /path/to/main.dart.dill 0'
             ))
           ));
+      final KernelCompiler kernelCompiler = await kernelCompilerFactory.create(null);
       final CompilerOutput output = await kernelCompiler.compile(sdkRoot: '/path/to/sdkroot',
         mainPath: '/path/to/main.dart',
         trackWidgetCreation: false,
@@ -144,6 +145,7 @@ example:org-dartlang-app:/
               'result abc\nline1\nline2\nabc\nabc'
             ))
           ));
+      final KernelCompiler kernelCompiler = await kernelCompilerFactory.create(null);
       final CompilerOutput output = await kernelCompiler.compile(sdkRoot: '/path/to/sdkroot',
         mainPath: '/path/to/main.dart',
         trackWidgetCreation: false,
@@ -169,6 +171,7 @@ example:org-dartlang-app:/
               'result abc\nline1\nline2\nabc\nabc'
           ))
       ));
+      final KernelCompiler kernelCompiler = await kernelCompilerFactory.create(null);
       final CompilerOutput output = await kernelCompiler.compile(
         sdkRoot: '/path/to/sdkroot',
         mainPath: '/path/to/main.dart',

packages/flutter_tools/test/tester/flutter_tester_test.dart

@@ -12,6 +12,7 @@ import 'package:flutter_tools/src/build_info.dart';
 import 'package:flutter_tools/src/cache.dart';
 import 'package:flutter_tools/src/compile.dart';
 import 'package:flutter_tools/src/device.dart';
+import 'package:flutter_tools/src/project.dart';
 import 'package:flutter_tools/src/tester/flutter_tester.dart';
 import 'package:mockito/mockito.dart';
 import 'package:process/process.dart';
@@ -109,7 +110,7 @@ void main() {
         FileSystem: () => fs,
         Cache: () => Cache(rootOverride: fs.directory(flutterRoot)),
         ProcessManager: () => mockProcessManager,
-        KernelCompiler: () => mockKernelCompiler,
+        KernelCompilerFactory: () => FakeKernelCompilerFactory(mockKernelCompiler),
         Artifacts: () => mockArtifacts,
       };
 
@@ -185,7 +186,6 @@ Hello!
             debuggingOptions: DebuggingOptions.enabled(const BuildInfo(BuildMode.debug, null)));
         expect(result.started, isTrue);
         expect(result.observatoryUri, observatoryUri);
-
         expect(logLines.last, 'Hello!');
       }, overrides: startOverrides);
     });
@@ -194,3 +194,13 @@ Hello!
 
 class MockArtifacts extends Mock implements Artifacts {}
 class MockKernelCompiler extends Mock implements KernelCompiler {}
+class FakeKernelCompilerFactory implements KernelCompilerFactory {
+  FakeKernelCompilerFactory(this.kernelCompiler);
+
+  final KernelCompiler kernelCompiler;
+
+  @override
+  Future<KernelCompiler> create(FlutterProject flutterProject) async {
+    return kernelCompiler;
+  }
+}