Add a flag to enable dart:mirrors (#19112)

Fixes https://github.com/flutter/flutter/issues/59233

shell/platform/linux/fl_dart_project.cc

@@ -9,6 +9,7 @@
 struct _FlDartProject {
   GObject parent_instance;
 
+  gboolean enable_mirrors;
   gchar* aot_library_path;
   gchar* assets_path;
   gchar* icu_data_path;
@@ -60,6 +61,19 @@ G_MODULE_EXPORT FlDartProject* fl_dart_project_new() {
   return self;
 }
 
+G_MODULE_EXPORT void fl_dart_project_set_enable_mirrors(
+    FlDartProject* self,
+    gboolean enable_mirrors) {
+  g_return_if_fail(FL_IS_DART_PROJECT(self));
+  self->enable_mirrors = enable_mirrors;
+}
+
+G_MODULE_EXPORT gboolean
+fl_dart_project_get_enable_mirrors(FlDartProject* self) {
+  g_return_val_if_fail(FL_IS_DART_PROJECT(self), FALSE);
+  return self->enable_mirrors;
+}
+
 G_MODULE_EXPORT const gchar* fl_dart_project_get_aot_library_path(
     FlDartProject* self) {
   g_return_val_if_fail(FL_IS_DART_PROJECT(self), nullptr);

shell/platform/linux/fl_dart_project_test.cc

@@ -24,3 +24,12 @@ TEST(FlDartProjectTest, GetPaths) {
   EXPECT_STREQ(fl_dart_project_get_icu_data_path(project),
                expected_icu_data_path);
 }
+
+TEST(FlDartProjectTest, EnableMirrors) {
+  g_autoptr(FlDartProject) project = fl_dart_project_new();
+  G_GNUC_BEGIN_IGNORE_DEPRECATIONS
+  EXPECT_FALSE(fl_dart_project_get_enable_mirrors(project));
+  fl_dart_project_set_enable_mirrors(project, TRUE);
+  EXPECT_TRUE(fl_dart_project_get_enable_mirrors(project));
+  G_GNUC_END_IGNORE_DEPRECATIONS
+}

shell/platform/linux/fl_engine.cc

@@ -274,10 +274,24 @@ gboolean fl_engine_start(FlEngine* self, GError** error) {
   custom_task_runners.struct_size = sizeof(FlutterCustomTaskRunners);
   custom_task_runners.platform_task_runner = &platform_task_runner;
 
+  g_autoptr(GPtrArray) command_line_args =
+      g_ptr_array_new_with_free_func(g_free);
+  g_ptr_array_add(command_line_args, g_strdup("flutter"));
+  G_GNUC_BEGIN_IGNORE_DEPRECATIONS
+  gboolean enable_mirrors = fl_dart_project_get_enable_mirrors(self->project);
+  G_GNUC_END_IGNORE_DEPRECATIONS
+  if (enable_mirrors) {
+    g_ptr_array_add(command_line_args,
+                    g_strdup("--dart-flags=--enable_mirrors=true"));
+  }
+
   FlutterProjectArgs args = {};
   args.struct_size = sizeof(FlutterProjectArgs);
   args.assets_path = fl_dart_project_get_assets_path(self->project);
   args.icu_data_path = fl_dart_project_get_icu_data_path(self->project);
+  args.command_line_argc = command_line_args->len;
+  args.command_line_argv =
+      reinterpret_cast<const char* const*>(command_line_args->pdata);
   args.platform_message_callback = fl_engine_platform_message_cb;
   args.custom_task_runners = &custom_task_runners;
   args.shutdown_dart_vm_when_done = true;

shell/platform/linux/public/flutter_linux/fl_dart_project.h

@@ -35,6 +35,33 @@ G_DECLARE_FINAL_TYPE(FlDartProject, fl_dart_project, FL, DART_PROJECT, GObject)
  */
 FlDartProject* fl_dart_project_new();
 
+/**
+ * fl_dart_project_set_enable_mirrors:
+ * @project: an #FlDartProject.
+ * @enable_mirrors: %TRUE if the dart:mirrors library should be used.
+ *
+ * Sets if this Flutter project can use the dart:mirrors library.
+ *
+ * Deprecated: This function is temporary and will be removed in a future
+ * release.
+ */
+void fl_dart_project_set_enable_mirrors(FlDartProject* project,
+                                        gboolean enable_mirrors) G_DEPRECATED;
+
+/**
+ * fl_dart_project_get_enable_mirrors:
+ * @project: an #FlDartProject.
+ *
+ * Gets if this Flutter project can use the dart:mirrors library.
+ *
+ * Returns: %TRUE if the dart:mirrors library can be used.
+ *
+ * Deprecated: This function is temporary and will be removed in a future
+ * release.
+ */
+gboolean fl_dart_project_get_enable_mirrors(FlDartProject* project)
+    G_DEPRECATED;
+
 /**
  * fl_dart_project_get_aot_library_path:
  * @project: an #FlDartProject.