Add flag to settings.h and clean up

Author: Emmanuel Garcia

common/settings.h

@@ -111,6 +111,9 @@ struct Settings {
   bool enable_dart_profiling = false;
   bool disable_dart_asserts = false;
 
+  // Whether the _registerPlugin function should be called when defined.
+  bool enable_dart_plugin_registrant = false;
+
   // Whether embedder only allows secure connections.
   bool may_insecurely_connect_to_all_domains = true;
   // JSON-formatted domain network policy.

runtime/dart_isolate.cc

@@ -182,9 +182,10 @@ std::weak_ptr<DartIsolate> DartIsolate::CreateRunningRootIsolate(
     settings.root_isolate_create_callback(*isolate.get());
   }
 
-  if (!isolate->RunFromLibrary(dart_entrypoint_library,       //
-                               dart_entrypoint,               //
-                               settings.dart_entrypoint_args  //
+  if (!isolate->RunFromLibrary(dart_entrypoint_library,                //
+                               dart_entrypoint,                        //
+                               settings.dart_entrypoint_args,          //
+                               settings.enable_dart_plugin_registrant  //
                                )) {
     FML_LOG(ERROR) << "Could not run the run main Dart entrypoint.";
     return {};
@@ -703,7 +704,8 @@ bool DartIsolate::MarkIsolateRunnable() {
 
 bool DartIsolate::RunFromLibrary(std::optional<std::string> library_name,
                                  std::optional<std::string> entrypoint,
-                                 const std::vector<std::string>& args) {
+                                 const std::vector<std::string>& args,
+                                 bool enable_dart_plugin_registrant) {
   TRACE_EVENT0("flutter", "DartIsolate::RunFromLibrary");
   if (phase_ != Phase::Ready) {
     return false;
@@ -737,14 +739,13 @@ bool DartIsolate::RunFromLibrary(std::optional<std::string> library_name,
   // as usual.
   //
   // This allows embeddings to change the name of the entrypoint function.
-  auto plugin_registrant_function =
-      ::Dart_GetField(library_handle, tonic::ToDart("_registerPlugins"));
-
-  if (Dart_IsError(plugin_registrant_function)) {
-    plugin_registrant_function = Dart_Null();
-    FML_DLOG(ERROR) << " plugin_registrant_function IS NULL  ";
-  } else {
-    FML_DLOG(ERROR) << " plugin_registrant_function IS NOT NULL  ";
+  auto plugin_registrant_function = Dart_Null();
+  if (enable_dart_plugin_registrant) {
+    auto defined_plugin_registrant_function =
+        ::Dart_GetField(library_handle, tonic::ToDart("_registerPlugins"));
+    if (!Dart_IsError(defined_plugin_registrant_function)) {
+      plugin_registrant_function = defined_plugin_registrant_function;
+    }
   }
 
   if (!InvokeMainEntrypoint(user_entrypoint_function,

runtime/dart_isolate.h

@@ -376,13 +376,15 @@ class DartIsolate : public UIDartState {
   ///                           supplied entrypoint.
   /// @param[in]  entrypoint    The entrypoint in `library_name`
   /// @param[in]  args          A list of string arguments to the entrypoint.
+  /// @param[in]  enable_dart_plugin_registrant  Calls the plugin registrant.
   ///
   /// @return     If the isolate successfully transitioned to the running phase
   ///             and the main entrypoint was invoked.
   ///
   [[nodiscard]] bool RunFromLibrary(std::optional<std::string> library_name,
                                     std::optional<std::string> entrypoint,
-                                    const std::vector<std::string>& args);
+                                    const std::vector<std::string>& args,
+                                    bool enable_dart_plugin_registrant);
 
   //----------------------------------------------------------------------------
   /// @brief      Transition the isolate to the `Phase::Shutdown` phase. The

runtime/dart_isolate_unittests.cc

@@ -613,8 +613,10 @@ TEST_F(DartIsolateTest, DartPluginRegistrantIsCalled) {
             messages.push_back(message);
             expected_messages.CountDown();
           })));
+  auto settings = CreateSettingsForFixture();
+  // This is set by default in switches.cc.
+  settings.enable_dart_plugin_registrant = true;
 
-  const auto settings = CreateSettingsForFixture();
   auto vm_ref = DartVMRef::Create(settings);
   auto thread = CreateNewThread();
   TaskRunners task_runners(GetCurrentTestName(),  //
@@ -623,8 +625,9 @@ TEST_F(DartIsolateTest, DartPluginRegistrantIsCalled) {
                            thread,                //
                            thread                 //
   );
-  auto isolate = RunDartCodeInIsolate(vm_ref, settings, task_runners, "main",
-                                      {}, GetFixturesPath());
+  auto isolate =
+      RunDartCodeInIsolate(vm_ref, settings, task_runners,
+                           "mainForDartRegistrantTest", {}, GetFixturesPath());
   ASSERT_TRUE(isolate);
   ASSERT_EQ(isolate->get()->GetPhase(), DartIsolate::Phase::Running);
   expected_messages.Wait();

runtime/fixtures/runtime_test.dart

@@ -10,22 +10,7 @@ import 'dart:ui';
 
 import 'split_lib_test.dart' deferred as splitlib;
 
-@pragma('vm:entry-point')
-void _registerPlugins() { // ignore: unused_element
-  try {
-    print('_registerPlugins');
-    passMessageForDartRegistrantTest('_registerPlugins');
-    print('_registerPlugins 2');
-  } catch(_) {}
-}
-
-void main() {
- try {
-    print('main');
-    passMessageForDartRegistrantTest('main');
-    print('main 2');
-  } catch(_) {}
-}
+void main() {}
 
 @pragma('vm:entry-point')
 void sayHi() {
@@ -73,7 +58,6 @@ void testCanSaveCompilationTrace() {
 
 void notifyResult(bool success) native 'NotifyNative';
 void passMessageForIsolateTest(String message) native 'PassMessageForIsolateTest';
-void passMessageForDartRegistrantTest(String message) native 'PassMessageForDartRegistrantTest';
 
 void secondaryIsolateMain(String message) {
   print('Secondary isolate got message: ' + message);
@@ -130,3 +114,18 @@ void testCanConvertListOfInts(List<int> args){
                 args[2] == 3 &&
                 args[3] == 4);
 }
+
+// Test the Dart plugin registrant.
+// _registerPlugins requires the entrypoint annotation, so the compiler doesn't tree shake it
+// in profile or release mode.
+@pragma('vm:entry-point')
+void _registerPlugins() { // ignore: unused_element
+  passMessageForDartRegistrantTest('_registerPlugins');
+}
+
+@pragma('vm:entry-point')
+void mainForDartRegistrantTest() {
+  passMessageForDartRegistrantTest('main');
+}
+
+void passMessageForDartRegistrantTest(String message) native 'PassMessageForDartRegistrantTest';

shell/common/switches.cc

@@ -415,6 +415,9 @@ Settings SettingsFromCommandLine(const fml::CommandLine& command_line) {
                                 &old_gen_heap_size);
     settings.old_gen_heap_size = std::stoi(old_gen_heap_size);
   }
+
+  settings.enable_dart_plugin_registrant = true;
+
   return settings;
 }