Revert "Starts using the `--source` flag to compile the dart registrant. (#98046) (#100493)

.ci.yaml

@@ -2628,30 +2628,6 @@ targets:
       - bin/**
       - .ci.yaml
 
-  - name: Mac entrypoint_dart_registrant
-    recipe: devicelab/devicelab_drone
-    bringup: true
-    timeout: 60
-    properties:
-      caches: >-
-        [
-          {"name":"gradle","path":"gradle"}
-        ]
-      dependencies: >-
-        [
-          {"dependency": "xcode"},
-          {"dependency": "gems"}
-        ]
-      tags: >
-        ["devicelab","hostonly"]
-      task_name: entrypoint_dart_registrant
-    scheduler: luci
-    runIf:
-      - dev/**
-      - packages/flutter_tools/**
-      - bin/**
-      - .ci.yaml
-
   - name: Mac framework_tests_libraries
     recipe: flutter/flutter_drone
     timeout: 60

TESTOWNERS

@@ -200,7 +200,6 @@
 /dev/devicelab/bin/tasks/gradle_plugin_light_apk_test.dart @stuartmorgan @flutter/plugin
 /dev/devicelab/bin/tasks/module_test_ios.dart @jmagman @flutter/tool
 /dev/devicelab/bin/tasks/plugin_lint_mac.dart @stuartmorgan @flutter/plugin
-/dev/devicelab/bin/tasks/entrypoint_dart_registrant.dart @aaclarke @flutter/plugin
 /dev/devicelab/bin/tasks/windows_home_scroll_perf__timeline_summary.dart @jonahwilliams @flutter/engine
 
 ## Host only framework tests

dev/devicelab/bin/tasks/entrypoint_dart_registrant.dart

-// Copyright 2014 The Flutter 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_devicelab/framework/devices.dart';
-import 'package:flutter_devicelab/framework/framework.dart';
-import 'package:flutter_devicelab/tasks/entrypoint_dart_registrant.dart';
-
-Future<void> main() async {
-  deviceOperatingSystem = DeviceOperatingSystem.android;
-  await task(entrypointDartRegistrant());
-}

dev/devicelab/lib/tasks/entrypoint_dart_registrant.dart

-// Copyright 2014 The Flutter 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 'dart:async';
-import 'dart:convert';
-import 'dart:io' show Process, ProcessSignal, Directory, File;
-
-import '../framework/devices.dart';
-import '../framework/framework.dart';
-import '../framework/task_result.dart';
-import '../framework/utils.dart';
-
-const String _messagePrefix = 'entrypoint:';
-const String _entrypointName = 'entrypoint';
-
-const String _dartCode = '''
-import 'package:flutter/widgets.dart';
-
-@pragma('vm:entry-point')
-void main() {
-  print('$_messagePrefix main');
-  runApp(const ColoredBox(color: Color(0xffcc0000)));
-}
-
-@pragma('vm:entry-point')
-void $_entrypointName() {
-  print('$_messagePrefix $_entrypointName');
-  runApp(const ColoredBox(color: Color(0xff00cc00)));
-}
-''';
-
-const String _kotlinCode = '''
-package com.example.entrypoint_dart_registrant
-
-import io.flutter.embedding.android.FlutterActivity
-
-class MainActivity: FlutterActivity() {
-  override fun getDartEntrypointFunctionName(): String {
-    return "$_entrypointName"
-  }
-}
-''';
-
-Future<TaskResult> _runWithTempDir(Directory tempDir) async {
-  const String testDirName = 'entrypoint_dart_registrant';
-  final String testPath = '${tempDir.path}/$testDirName';
-  await inDirectory(tempDir, () async {
-    await flutter('create', options: <String>[
-      '--platforms',
-      'android',
-      testDirName,
-    ]);
-  });
-  final String mainPath = '${tempDir.path}/$testDirName/lib/main.dart';
-  print(mainPath);
-  File(mainPath).writeAsStringSync(_dartCode);
-  final String activityPath =
-      '${tempDir.path}/$testDirName/android/app/src/main/kotlin/com/example/entrypoint_dart_registrant/MainActivity.kt';
-  File(activityPath).writeAsStringSync(_kotlinCode);
-  final Device device = await devices.workingDevice;
-  await device.unlock();
-  final String entrypoint = await inDirectory(testPath, () async {
-    // The problem only manifested when the dart plugin registrant was used
-    // (which path_provider has).
-    await flutter('pub', options: <String>['add', 'path_provider:2.0.9']);
-    // The problem only manifested on release builds, so we test release.
-    final Process process =
-        await startFlutter('run', options: <String>['--release']);
-    final Completer<String> completer = Completer<String>();
-    final StreamSubscription<String> stdoutSub = process.stdout
-        .transform<String>(const Utf8Decoder())
-        .transform<String>(const LineSplitter())
-        .listen((String line) async {
-      print(line);
-      if (line.contains(_messagePrefix)) {
-        completer.complete(line);
-      }
-    });
-    final String entrypoint = await completer.future;
-    await stdoutSub.cancel();
-    process.stdin.write('q');
-    await process.stdin.flush();
-    process.kill(ProcessSignal.sigint);
-    return entrypoint;
-  });
-  if (entrypoint.contains('$_messagePrefix $_entrypointName')) {
-    return TaskResult.success(null);
-  } else {
-    return TaskResult.failure('expected entrypoint:"$_entrypointName" but found:"$entrypoint"');
-  }
-}
-
-/// Asserts that the custom entrypoint works in the presence of the dart plugin
-/// registrant.
-TaskFunction entrypointDartRegistrant() {
-  return () async {
-    final Directory tempDir =
-        Directory.systemTemp.createTempSync('entrypoint_dart_registrant.');
-    try {
-      return await _runWithTempDir(tempDir);
-    } finally {
-      rmTree(tempDir);
-    }
-  };
-}

packages/flutter_tools/lib/src/build_system/targets/dart_plugin_registrant.dart

@@ -12,7 +12,7 @@ import '../../flutter_plugins.dart';
 import '../../project.dart';
 import '../build_system.dart';
 
-/// Generates a new `./dart_tool/flutter_build/dart_plugin_registrant.dart`
+/// Generates a new `./dart_tool/flutter_build/generated_main.dart`
 /// based on the current dependency map in `pubspec.lock`.
 class DartPluginRegistrantTarget extends Target {
   /// Construct a [DartPluginRegistrantTarget].
@@ -86,7 +86,7 @@ class DartPluginRegistrantTarget extends Target {
   @override
   List<Source> get outputs => <Source>[
     const Source.pattern(
-      '{PROJECT_DIR}/.dart_tool/flutter_build/dart_plugin_registrant.dart',
+      '{PROJECT_DIR}/.dart_tool/flutter_build/generated_main.dart',
       optional: true,
     ),
   ];

packages/flutter_tools/lib/src/compile.dart

@@ -261,12 +261,14 @@ class KernelCompiler {
     if (outputFilePath != null && !_fileSystem.isFileSync(outputFilePath)) {
       _fileSystem.file(outputFilePath).createSync(recursive: true);
     }
-
+    if (buildDir != null && checkDartPluginRegistry) {
       // Check if there's a Dart plugin registrant.
-    // This is contained in the file `dart_plugin_registrant.dart` under `.dart_tools/flutter_build/`.
-    final File? dartPluginRegistrant = checkDartPluginRegistry
-        ? buildDir?.parent.childFile('dart_plugin_registrant.dart')
-        : null;
+      // This is contained in the file `generated_main.dart` under `.dart_tools/flutter_build/`.
+      final File newMainDart = buildDir.parent.childFile('generated_main.dart');
+      if (newMainDart.existsSync()) {
+        mainUri = newMainDart.path;
+      }
+    }
 
     final List<String> command = <String>[
       engineDartPath,
@@ -314,10 +316,6 @@ class KernelCompiler {
         '--platform',
         platformDill,
       ],
-      if (dartPluginRegistrant != null && dartPluginRegistrant.existsSync()) ...<String>[
-        '--source',
-        dartPluginRegistrant.path,
-      ],
       ...?extraFrontEndOptions,
       mainUri,
     ];
@@ -361,7 +359,6 @@ class _RecompileRequest extends _CompilationRequest {
     this.outputPath,
     this.packageConfig,
     this.suppressErrors,
-    {this.additionalSource}
   ) : super(completer);
 
   Uri mainUri;
@@ -369,7 +366,6 @@ class _RecompileRequest extends _CompilationRequest {
   String outputPath;
   PackageConfig packageConfig;
   bool suppressErrors;
-  final String? additionalSource;
 
   @override
   Future<CompilerOutput?> _run(DefaultResidentCompiler compiler) async =>
@@ -635,31 +631,24 @@ class DefaultResidentCompiler implements ResidentCompiler {
     if (!_controller.hasListener) {
       _controller.stream.listen(_handleCompilationRequest);
     }
-    String? additionalSource;
-    // `dart_plugin_registrant.dart` contains the Dart plugin registry.
+    // `generated_main.dart` contains the Dart plugin registry.
     if (checkDartPluginRegistry && projectRootPath != null && fs != null) {
-      final File dartPluginRegistrantDart = fs.file(
+      final File generatedMainDart = fs.file(
         fs.path.join(
           projectRootPath,
           '.dart_tool',
           'flutter_build',
-          'dart_plugin_registrant.dart',
+          'generated_main.dart',
         ),
       );
-      if (dartPluginRegistrantDart != null && dartPluginRegistrantDart.existsSync()) {
-        additionalSource = dartPluginRegistrantDart.path;
+      if (generatedMainDart != null && generatedMainDart.existsSync()) {
+        mainUri = generatedMainDart.uri;
       }
     }
     final Completer<CompilerOutput?> completer = Completer<CompilerOutput?>();
-    _controller.add(_RecompileRequest(
-      completer,
-      mainUri,
-      invalidatedFiles,
-      outputPath,
-      packageConfig,
-      suppressErrors,
-      additionalSource: additionalSource,
-    ));
+    _controller.add(
+      _RecompileRequest(completer, mainUri, invalidatedFiles, outputPath, packageConfig, suppressErrors)
+    );
     return completer.future;
   }
 
@@ -673,7 +662,7 @@ class DefaultResidentCompiler implements ResidentCompiler {
 
     final Process? server = _server;
     if (server == null) {
-      return _compile(mainUri, request.outputPath, additionalSource: request.additionalSource);
+      return _compile(mainUri, request.outputPath);
     }
     final String inputKey = Uuid().generateV4();
 
@@ -719,7 +708,6 @@ class DefaultResidentCompiler implements ResidentCompiler {
   Future<CompilerOutput?> _compile(
     String scriptUri,
     String? outputPath,
-    {String? additionalSource}
   ) async {
     final String frontendServer = _artifacts.getArtifactPath(
       Artifact.frontendServerSnapshotForEngineDartSdk
@@ -772,10 +760,6 @@ class DefaultResidentCompiler implements ResidentCompiler {
         initializeFromDill!,
       ],
       if (assumeInitializeFromDillUpToDate) '--assume-initialize-from-dill-up-to-date',
-      if (additionalSource != null) ...<String>[
-        '--source',
-        additionalSource,
-      ],
       if (platformDill != null) ...<String>[
         '--platform',
         platformDill!,

packages/flutter_tools/lib/src/flutter_plugins.dart

@@ -706,6 +706,10 @@ const String _dartPluginRegistryForNonWebTemplate = '''
 
 // @dart = {{dartLanguageVersion}}
 
+// When `{{mainEntrypoint}}` defines `main`, that definition is shadowed by the definition below.
+export '{{mainEntrypoint}}';
+
+import '{{mainEntrypoint}}' as entrypoint;
 import 'dart:io'; // flutter_ignore: dart_io_import.
 {{#android}}
 import 'package:{{pluginName}}/{{pluginName}}.dart';
@@ -750,6 +754,18 @@ $_dartPluginRegisterWith
       {{/windows}}
     }
   }
+
+}
+
+typedef _UnaryFunction = dynamic Function(List<String> args);
+typedef _NullaryFunction = dynamic Function();
+
+void main(List<String> args) {
+  if (entrypoint.main is _UnaryFunction) {
+    (entrypoint.main as _UnaryFunction)(args);
+  } else {
+    (entrypoint.main as _NullaryFunction)();
+  }
 }
 ''';
 

packages/flutter_tools/lib/src/project.dart

@@ -236,7 +236,7 @@ class FlutterProject {
   /// The generated Dart plugin registrant for non-web platforms.
   File get dartPluginRegistrant => dartTool
     .childDirectory('flutter_build')
-    .childFile('dart_plugin_registrant.dart');
+    .childFile('generated_main.dart');
 
   /// The example sub-project of this project.
   FlutterProject get example => FlutterProject(

packages/flutter_tools/test/general.shard/build_system/targets/dart_plugin_registrant_test.dart

@@ -159,7 +159,7 @@ void main() {
       }
     });
 
-    testUsingContext("doesn't generate dart_plugin_registrant.dart if there aren't Dart plugins", () async {
+    testUsingContext("doesn't generate generated_main.dart if there aren't Dart plugins", () async {
       final Directory projectDir = fileSystem.directory('project')..createSync();
       final Environment environment = Environment.test(
           fileSystem.currentDirectory,
@@ -189,11 +189,11 @@ void main() {
       final File generatedMain = projectDir
           .childDirectory('.dart_tool')
           .childDirectory('flutter_build')
-          .childFile('dart_plugin_registrant.dart');
+          .childFile('generated_main.dart');
       expect(generatedMain.existsSync(), isFalse);
     });
 
-    testUsingContext('regenerates dart_plugin_registrant.dart', () async {
+    testUsingContext('regenerates generated_main.dart', () async {
       final Directory projectDir = fileSystem.directory('project')..createSync();
       final Environment environment = Environment.test(
           fileSystem.currentDirectory,
@@ -231,7 +231,7 @@ void main() {
       final File generatedMain = projectDir
           .childDirectory('.dart_tool')
           .childDirectory('flutter_build')
-          .childFile('dart_plugin_registrant.dart');
+          .childFile('generated_main.dart');
       final String mainContent = generatedMain.readAsStringSync();
       expect(
         mainContent,
@@ -243,6 +243,10 @@ void main() {
           '\n'
           '// @dart = 2.12\n'
           '\n'
+          '// When `package:path_provider_example/main.dart` defines `main`, that definition is shadowed by the definition below.\n'
+          "export 'package:path_provider_example/main.dart';\n"
+          '\n'
+          "import 'package:path_provider_example/main.dart' as entrypoint;\n"
           "import 'dart:io'; // flutter_ignore: dart_io_import.\n"
           "import 'package:path_provider_linux/path_provider_linux.dart';\n"
           '\n'
@@ -268,12 +272,24 @@ void main() {
           '    } else if (Platform.isWindows) {\n'
           '    }\n'
           '  }\n'
+          '\n'
+          '}\n'
+          '\n'
+          'typedef _UnaryFunction = dynamic Function(List<String> args);\n'
+          'typedef _NullaryFunction = dynamic Function();\n'
+          '\n'
+          'void main(List<String> args) {\n'
+          '  if (entrypoint.main is _UnaryFunction) {\n'
+          '    (entrypoint.main as _UnaryFunction)(args);\n'
+          '  } else {\n'
+          '    (entrypoint.main as _NullaryFunction)();\n'
+          '  }\n'
           '}\n'
         ),
       );
     });
 
-    testUsingContext('removes dart_plugin_registrant.dart if plugins are removed from pubspec.yaml', () async {
+    testUsingContext('removes generated_main.dart if plugins are removed from pubspec.yaml', () async {
       final Directory projectDir = fileSystem.directory('project')..createSync();
       final Environment environment = Environment.test(
           fileSystem.currentDirectory,
@@ -305,7 +321,7 @@ void main() {
       final File generatedMain = projectDir
           .childDirectory('.dart_tool')
           .childDirectory('flutter_build')
-          .childFile('dart_plugin_registrant.dart');
+          .childFile('generated_main.dart');
 
       final FlutterProject testProject = FlutterProject.fromDirectoryTest(projectDir);
       await DartPluginRegistrantTarget.test(testProject).build(environment);
@@ -356,7 +372,7 @@ void main() {
       final File generatedMain = projectDir
           .childDirectory('.dart_tool')
           .childDirectory('flutter_build')
-          .childFile('dart_plugin_registrant.dart');
+          .childFile('generated_main.dart');
 
       final String mainContent = generatedMain.readAsStringSync();
       expect(
@@ -369,6 +385,10 @@ void main() {
           '\n'
           '// @dart = 2.12\n'
           '\n'
+          '// When `file:///root/external.dart` defines `main`, that definition is shadowed by the definition below.\n'
+          "export 'file:///root/external.dart';\n"
+          '\n'
+          "import 'file:///root/external.dart' as entrypoint;\n"
           "import 'dart:io'; // flutter_ignore: dart_io_import.\n"
           "import 'package:path_provider_linux/path_provider_linux.dart';\n"
           '\n'
@@ -394,6 +414,18 @@ void main() {
           '    } else if (Platform.isWindows) {\n'
           '    }\n'
           '  }\n'
+          '\n'
+          '}\n'
+          '\n'
+          'typedef _UnaryFunction = dynamic Function(List<String> args);\n'
+          'typedef _NullaryFunction = dynamic Function();\n'
+          '\n'
+          'void main(List<String> args) {\n'
+          '  if (entrypoint.main is _UnaryFunction) {\n'
+          '    (entrypoint.main as _UnaryFunction)(args);\n'
+          '  } else {\n'
+          '    (entrypoint.main as _NullaryFunction)();\n'
+          '  }\n'
           '}\n'
         ),
       );

packages/flutter_tools/test/general.shard/compile_batch_test.dart

@@ -395,9 +395,7 @@ void main() {
           '--no-link-platform',
           '--packages',
           '.packages',
-          '--source',
-          '.dart_tools/flutter_build/dart_plugin_registrant.dart',
-          'scheme:///main.dart',
+          '.dart_tools/flutter_build/generated_main.dart',
         ], completer: completer),
       ]),
       stdoutHandler: stdoutHandler,
@@ -407,7 +405,7 @@ void main() {
         .childDirectory('flutter_build')
         .childDirectory('test');
 
-    buildDir.parent.childFile('dart_plugin_registrant.dart').createSync(recursive: true);
+    buildDir.parent.childFile('generated_main.dart').createSync(recursive: true);
 
     final Future<CompilerOutput?> output = kernelCompiler.compile(sdkRoot: '/path/to/sdkroot',
       mainPath: '/foo/bar/fizz/main.dart',

packages/flutter_tools/test/general.shard/dart_plugin_test.dart

@@ -35,7 +35,7 @@ void main() {
         ..directory = directory
         ..flutterPluginsFile = directory.childFile('.flutter-plugins')
         ..flutterPluginsDependenciesFile = directory.childFile('.flutter-plugins-dependencies')
-        ..dartPluginRegistrant = directory.childFile('dart_plugin_registrant.dart');
+        ..dartPluginRegistrant = directory.childFile('generated_main.dart');
       flutterProject.directory.childFile('.packages').createSync(recursive: true);
     });
 
@@ -701,6 +701,206 @@ void main() {
           '\n'
           '// @dart = 2.8\n'
           '\n'
+          '// When `package:app/main.dart` defines `main`, that definition is shadowed by the definition below.\n'
+          "export 'package:app/main.dart';\n"
+          '\n'
+          "import 'package:app/main.dart' as entrypoint;\n"
+          "import 'dart:io'; // flutter_ignore: dart_io_import.\n"
+          "import 'package:url_launcher_android/url_launcher_android.dart';\n"
+          "import 'package:url_launcher_ios/url_launcher_ios.dart';\n"
+          "import 'package:url_launcher_linux/url_launcher_linux.dart';\n"
+          "import 'package:awesome_macos/awesome_macos.dart';\n"
+          "import 'package:url_launcher_macos/url_launcher_macos.dart';\n"
+          "import 'package:url_launcher_windows/url_launcher_windows.dart';\n"
+          '\n'
+          "@pragma('vm:entry-point')\n"
+          'class _PluginRegistrant {\n'
+          '\n'
+          "  @pragma('vm:entry-point')\n"
+          '  static void register() {\n'
+          '    if (Platform.isAndroid) {\n'
+          '      try {\n'
+          '        AndroidPlugin.registerWith();\n'
+          '      } catch (err) {\n'
+          '        print(\n'
+          "          '`url_launcher_android` threw an error: \$err. '\n"
+          "          'The app may not function as expected until you remove this plugin from pubspec.yaml'\n"
+          '        );\n'
+          '        rethrow;\n'
+          '      }\n'
+          '\n'
+          '    } else if (Platform.isIOS) {\n'
+          '      try {\n'
+          '        IosPlugin.registerWith();\n'
+          '      } catch (err) {\n'
+          '        print(\n'
+          "          '`url_launcher_ios` threw an error: \$err. '\n"
+          "          'The app may not function as expected until you remove this plugin from pubspec.yaml'\n"
+          '        );\n'
+          '        rethrow;\n'
+          '      }\n'
+          '\n'
+          '    } else if (Platform.isLinux) {\n'
+          '      try {\n'
+          '        LinuxPlugin.registerWith();\n'
+          '      } catch (err) {\n'
+          '        print(\n'
+          "          '`url_launcher_linux` threw an error: \$err. '\n"
+          "          'The app may not function as expected until you remove this plugin from pubspec.yaml'\n"
+          '        );\n'
+          '        rethrow;\n'
+          '      }\n'
+          '\n'
+          '    } else if (Platform.isMacOS) {\n'
+          '      try {\n'
+          '        AwesomeMacOS.registerWith();\n'
+          '      } catch (err) {\n'
+          '        print(\n'
+          "          '`awesome_macos` threw an error: \$err. '\n"
+          "          'The app may not function as expected until you remove this plugin from pubspec.yaml'\n"
+          '        );\n'
+          '        rethrow;\n'
+          '      }\n'
+          '\n'
+          '      try {\n'
+          '        MacOSPlugin.registerWith();\n'
+          '      } catch (err) {\n'
+          '        print(\n'
+          "          '`url_launcher_macos` threw an error: \$err. '\n"
+          "          'The app may not function as expected until you remove this plugin from pubspec.yaml'\n"
+          '        );\n'
+          '        rethrow;\n'
+          '      }\n'
+          '\n'
+          '    } else if (Platform.isWindows) {\n'
+          '      try {\n'
+          '        WindowsPlugin.registerWith();\n'
+          '      } catch (err) {\n'
+          '        print(\n'
+          "          '`url_launcher_windows` threw an error: \$err. '\n"
+          "          'The app may not function as expected until you remove this plugin from pubspec.yaml'\n"
+          '        );\n'
+          '        rethrow;\n'
+          '      }\n'
+          '\n'
+          '    }\n'
+          '  }\n'
+          '\n'
+          '}\n'
+          '\n'
+          'typedef _UnaryFunction = dynamic Function(List<String> args);\n'
+          'typedef _NullaryFunction = dynamic Function();\n'
+          '\n'
+          'void main(List<String> args) {\n'
+          '  if (entrypoint.main is _UnaryFunction) {\n'
+          '    (entrypoint.main as _UnaryFunction)(args);\n'
+          '  } else {\n'
+          '    (entrypoint.main as _NullaryFunction)();\n'
+          '  }\n'
+          '}\n',
+        );
+      }, overrides: <Type, Generator>{
+        FileSystem: () => fs,
+        ProcessManager: () => FakeProcessManager.any(),
+      });
+
+      testUsingContext('Rewires entrypoints', () async {
+        flutterProject.isModule = true;
+
+        createFakeDartPlugins(
+          flutterProject,
+          flutterManifest,
+          fs,
+          <String, String>{
+            'url_launcher_android': '''
+  flutter:
+    plugin:
+      implements: url_launcher
+      platforms:
+        android:
+          dartPluginClass: AndroidPlugin
+''',
+          'url_launcher_ios': '''
+  flutter:
+    plugin:
+      implements: url_launcher
+      platforms:
+        ios:
+          dartPluginClass: IosPlugin
+''',
+          'url_launcher_macos': '''
+  flutter:
+    plugin:
+      implements: url_launcher
+      platforms:
+        macos:
+          dartPluginClass: MacOSPlugin
+''',
+         'url_launcher_linux': '''
+  flutter:
+    plugin:
+      implements: url_launcher
+      platforms:
+        linux:
+          dartPluginClass: LinuxPlugin
+''',
+         'url_launcher_windows': '''
+  flutter:
+    plugin:
+      implements: url_launcher
+      platforms:
+        windows:
+          dartPluginClass: WindowsPlugin
+''',
+         'awesome_macos': '''
+  flutter:
+    plugin:
+      implements: awesome
+      platforms:
+        macos:
+          dartPluginClass: AwesomeMacOS
+'''
+          });
+
+        final Directory libDir = flutterProject.directory.childDirectory('lib');
+        libDir.createSync(recursive: true);
+
+        final File mainFile = libDir.childFile('main.dart');
+        mainFile.writeAsStringSync('''
+// @dart = 2.8
+void main() {
+}
+
+@pragma('vm:entry-point')
+void dream() => run(interactive: false);
+
+@pragma('vm:entry-point', foobar)
+void dreamWithFlags() => run(interactive: false);
+''');
+        final PackageConfig packageConfig = await loadPackageConfigWithLogging(
+          flutterProject.directory.childDirectory('.dart_tool').childFile('package_config.json'),
+          logger: globals.logger,
+          throwOnError: false,
+        );
+        await generateMainDartWithPluginRegistrant(
+          flutterProject,
+          packageConfig,
+          'package:app/main.dart',
+          mainFile,
+          throwOnPluginPubspecError: true,
+        );
+        expect(flutterProject.dartPluginRegistrant.readAsStringSync(),
+          '//\n'
+          '// Generated file. Do not edit.\n'
+          '// This file is generated from template in file `flutter_tools/lib/src/flutter_plugins.dart`.\n'
+          '//\n'
+          '\n'
+          '// @dart = 2.8\n'
+          '\n'
+          '// When `package:app/main.dart` defines `main`, that definition is shadowed by the definition below.\n'
+          "export 'package:app/main.dart';\n"
+          '\n'
+          "import 'package:app/main.dart' as entrypoint;\n"
           "import 'dart:io'; // flutter_ignore: dart_io_import.\n"
           "import 'package:url_launcher_android/url_launcher_android.dart';\n"
           "import 'package:url_launcher_ios/url_launcher_ios.dart';\n"
@@ -781,7 +981,20 @@ void main() {
           '\n'
           '    }\n'
           '  }\n'
+          '\n'
+          '}\n'
+          '\n'
+          'typedef _UnaryFunction = dynamic Function(List<String> args);\n'
+          'typedef _NullaryFunction = dynamic Function();\n'
+          '\n'
+          'void main(List<String> args) {\n'
+          '  if (entrypoint.main is _UnaryFunction) {\n'
+          '    (entrypoint.main as _UnaryFunction)(args);\n'
+          '  } else {\n'
+          '    (entrypoint.main as _NullaryFunction)();\n'
+          '  }\n'
           '}\n'
+          ,
         );
       }, overrides: <Type, Generator>{
         FileSystem: () => fs,

packages/flutter_tools/test/general.shard/resident_runner_test.dart

@@ -1189,8 +1189,8 @@ void main() {
   ]
 }
 ''');
-    // Start from an empty dart_plugin_registrant.dart file.
-    globals.fs.directory('.dart_tool').childDirectory('flutter_build').childFile('dart_plugin_registrant.dart').createSync(recursive: true);
+    // Start from an empty generated_main.dart file.
+    globals.fs.directory('.dart_tool').childDirectory('flutter_build').childFile('generated_main.dart').createSync(recursive: true);
 
     await residentRunner.runSourceGenerators();
 
@@ -1267,9 +1267,9 @@ flutter:
 
     final File generatedMain = globals.fs.directory('.dart_tool')
         .childDirectory('flutter_build')
-        .childFile('dart_plugin_registrant.dart');
+        .childFile('generated_main.dart');
 
-    expect(generatedMain.existsSync(), isTrue);
+    expect(generatedMain.readAsStringSync(), contains('custom_main.dart'));
     expect(testLogger.errorText, isEmpty);
     expect(testLogger.statusText, isEmpty);
   }));

packages/flutter_tools/test/general.shard/resident_web_runner_test.dart

@@ -936,7 +936,7 @@ void main() {
 
   // While this file should be ignored on web, generating it here will cause a
   // perf regression in hot restart.
-  testUsingContext('Does not generate dart_plugin_registrant.dart', () async {
+  testUsingContext('Does not generate generated_main.dart', () async {
     // Create necessary files for [DartPluginRegistrantTarget]
     final File packageConfig = globals.fs.directory('.dart_tool')
         .childFile('package_config.json');
@@ -954,10 +954,10 @@ void main() {
   ]
 }
 ''');
-    // Start with a dart_plugin_registrant.dart file.
+    // Start with a generated_main.dart file.
     globals.fs.directory('.dart_tool')
               .childDirectory('flutter_build')
-              .childFile('dart_plugin_registrant.dart')
+              .childFile('generated_main.dart')
               .createSync(recursive: true);
 
     final FlutterProject project = FlutterProject.fromDirectoryTest(fileSystem.currentDirectory);
@@ -965,7 +965,7 @@ void main() {
     final ResidentRunner residentWebRunner = setUpResidentRunner(flutterDevice);
     await residentWebRunner.runSourceGenerators();
 
-    // dart_plugin_registrant.dart should be untouched, indicating that its
+    // generated_main.dart should be untouched, indicating that its
     // generation didn't run. If it had run, the file would have been removed as
     // there are no plugins in the project.
     expect(project.dartPluginRegistrant.existsSync(), true);

packages/flutter_tools/test/general.shard/test/test_compiler_test.dart

@@ -115,7 +115,7 @@ void main() {
     Logger: () => BufferLogger.test(),
   });
 
-  testUsingContext('TestCompiler updates dart_plugin_registrant.dart', () async {
+  testUsingContext('TestCompiler updates generated_main.dart', () async {
     final Directory fakeDartPlugin = fileSystem.directory('a_plugin');
       fileSystem.file('pubspec.yaml').writeAsStringSync('''
 name: foo
@@ -152,12 +152,12 @@ environment:
     final File generatedMain = fileSystem
       .directory('.dart_tool')
       .childDirectory('flutter_build')
-      .childFile('dart_plugin_registrant.dart');
+      .childFile('generated_main.dart');
 
     expect(generatedMain, exists);
     expect(
-      generatedMain.readAsStringSync(),
-      contains('APlugin.registerWith();')
+      generatedMain.readAsLinesSync(),
+      contains("import 'test/foo.dart' as entrypoint;")
     );
   }, overrides: <Type, Generator>{
     FileSystem: () => fileSystem,