[pigeon] Make Linux type declarations public (#8040)

Moves codec and HostAPI class declarations to the header to work around a glib bug. We could instead add an unnecessary call to the type check method, but we will need the codec to be public eventually anyway, and HostApi is conceptually a public class (it just isn't strictly necessary to declare it in the header due to the way abstract interfaces work in gobject) so may as well be declared publicly.

Part of flutter/flutter#153083

packages/pigeon/CHANGELOG.md

@@ -1,3 +1,8 @@
+## 22.6.1
+
+* [gobject] Moves class declarations to the header to work around a bug in some
+  versions of glib.
+
 ## 22.6.0
 
 * [swift] Adds `includeErrorClass` to `SwiftOptions`.

packages/pigeon/example/app/linux/messages.g.cc

@@ -118,11 +118,6 @@ pigeon_example_package_message_data_new_from_list(FlValue* values) {
   return pigeon_example_package_message_data_new(name, description, code, data);
 }
 
-G_DECLARE_FINAL_TYPE(PigeonExamplePackageMessageCodec,
-                     pigeon_example_package_message_codec,
-                     PIGEON_EXAMPLE_PACKAGE, MESSAGE_CODEC,
-                     FlStandardMessageCodec)
-
 struct _PigeonExamplePackageMessageCodec {
   FlStandardMessageCodec parent_instance;
 };
@@ -468,10 +463,6 @@ pigeon_example_package_example_host_api_send_message_response_new_error(
   return self;
 }
 
-G_DECLARE_FINAL_TYPE(PigeonExamplePackageExampleHostApi,
-                     pigeon_example_package_example_host_api,
-                     PIGEON_EXAMPLE_PACKAGE, EXAMPLE_HOST_API, GObject)
-
 struct _PigeonExamplePackageExampleHostApi {
   GObject parent_instance;
 

packages/pigeon/example/app/linux/messages.g.h

@@ -90,6 +90,15 @@ PigeonExamplePackageCode pigeon_example_package_message_data_get_code(
 FlValue* pigeon_example_package_message_data_get_data(
     PigeonExamplePackageMessageData* object);
 
+G_DECLARE_FINAL_TYPE(PigeonExamplePackageMessageCodec,
+                     pigeon_example_package_message_codec,
+                     PIGEON_EXAMPLE_PACKAGE, MESSAGE_CODEC,
+                     FlStandardMessageCodec)
+
+G_DECLARE_FINAL_TYPE(PigeonExamplePackageExampleHostApi,
+                     pigeon_example_package_example_host_api,
+                     PIGEON_EXAMPLE_PACKAGE, EXAMPLE_HOST_API, GObject)
+
 G_DECLARE_FINAL_TYPE(PigeonExamplePackageExampleHostApiResponseHandle,
                      pigeon_example_package_example_host_api_response_handle,
                      PIGEON_EXAMPLE_PACKAGE, EXAMPLE_HOST_API_RESPONSE_HANDLE,

packages/pigeon/lib/generator_tools.dart

@@ -14,7 +14,7 @@ import 'ast.dart';
 /// The current version of pigeon.
 ///
 /// This must match the version in pubspec.yaml.
-const String pigeonVersion = '22.6.0';
+const String pigeonVersion = '22.6.1';
 
 /// Read all the content from [stdin] to a String.
 String readStdin() {

packages/pigeon/lib/gobject_generator.dart

@@ -14,6 +14,9 @@ const DocumentCommentSpecification _docCommentSpec =
 /// Name for codec class.
 const String _codecBaseName = 'MessageCodec';
 
+/// Name of the standard codec from the Flutter SDK.
+const String _standardCodecName = 'FlStandardMessageCodec';
+
 /// Options that control how GObject code will be generated.
 class GObjectOptions {
   /// Creates a [GObjectOptions] object
@@ -282,7 +285,12 @@ class GObjectHeaderGenerator extends StructuredGenerator<GObjectOptions> {
     Root root,
     Indent indent, {
     required String dartPackageName,
-  }) {}
+  }) {
+    final String module = _getModule(generatorOptions, dartPackageName);
+    indent.newln();
+    _writeDeclareFinalType(indent, module, _codecBaseName,
+        parentClassName: _standardCodecName);
+  }
 
   @override
   void writeFlutterApi(
@@ -508,6 +516,9 @@ class GObjectHeaderGenerator extends StructuredGenerator<GObjectOptions> {
     final String methodPrefix = _getMethodPrefix(module, api.name);
     final String vtableName = _getVTableName(module, api.name);
 
+    indent.newln();
+    _writeDeclareFinalType(indent, module, api.name);
+
     final bool hasAsyncMethod =
         api.methods.any((Method method) => method.isAsynchronous);
     if (hasAsyncMethod) {
@@ -950,13 +961,9 @@ class GObjectSourceGenerator extends StructuredGenerator<GObjectOptions> {
 
     final Iterable<EnumeratedType> customTypes = getEnumeratedTypes(root);
 
-    indent.newln();
-    _writeDeclareFinalType(indent, module, _codecBaseName,
-        parentClassName: 'FlStandardMessageCodec');
-
     indent.newln();
     _writeObjectStruct(indent, module, _codecBaseName, () {},
-        parentClassName: 'FlStandardMessageCodec');
+        parentClassName: _standardCodecName);
 
     indent.newln();
     _writeDefineType(indent, module, _codecBaseName,
@@ -971,7 +978,7 @@ class GObjectSourceGenerator extends StructuredGenerator<GObjectOptions> {
           ? '$customTypeName*'
           : 'FlValue*';
       indent.writeScoped(
-          'static gboolean ${codecMethodPrefix}_write_$snakeCustomTypeName(FlStandardMessageCodec* codec, GByteArray* buffer, $valueType value, GError** error) {',
+          'static gboolean ${codecMethodPrefix}_write_$snakeCustomTypeName($_standardCodecName* codec, GByteArray* buffer, $valueType value, GError** error) {',
           '}', () {
         indent.writeln('uint8_t type = ${customType.enumeration};');
         indent.writeln('g_byte_array_append(buffer, &type, sizeof(uint8_t));');
@@ -989,7 +996,7 @@ class GObjectSourceGenerator extends StructuredGenerator<GObjectOptions> {
 
     indent.newln();
     indent.writeScoped(
-        'static gboolean ${codecMethodPrefix}_write_value(FlStandardMessageCodec* codec, GByteArray* buffer, FlValue* value, GError** error) {',
+        'static gboolean ${codecMethodPrefix}_write_value($_standardCodecName* codec, GByteArray* buffer, FlValue* value, GError** error) {',
         '}', () {
       indent.writeScoped(
           'if (fl_value_get_type(value) == FL_VALUE_TYPE_CUSTOM) {', '}', () {
@@ -1027,7 +1034,7 @@ class GObjectSourceGenerator extends StructuredGenerator<GObjectOptions> {
           _snakeCaseFromCamelCase(customTypeName);
       indent.newln();
       indent.writeScoped(
-          'static FlValue* ${codecMethodPrefix}_read_$snakeCustomTypeName(FlStandardMessageCodec* codec, GBytes* buffer, size_t* offset, GError** error) {',
+          'static FlValue* ${codecMethodPrefix}_read_$snakeCustomTypeName($_standardCodecName* codec, GBytes* buffer, size_t* offset, GError** error) {',
           '}', () {
         if (customType.type == CustomTypes.customClass) {
           indent.writeln(
@@ -1055,7 +1062,7 @@ class GObjectSourceGenerator extends StructuredGenerator<GObjectOptions> {
 
     indent.newln();
     indent.writeScoped(
-        'static FlValue* ${codecMethodPrefix}_read_value_of_type(FlStandardMessageCodec* codec, GBytes* buffer, size_t* offset, int type, GError** error) {',
+        'static FlValue* ${codecMethodPrefix}_read_value_of_type($_standardCodecName* codec, GBytes* buffer, size_t* offset, int type, GError** error) {',
         '}', () {
       indent.writeScoped('switch (type) {', '}', () {
         for (final EnumeratedType customType in customTypes) {
@@ -1473,9 +1480,6 @@ class GObjectSourceGenerator extends StructuredGenerator<GObjectOptions> {
       });
     }
 
-    indent.newln();
-    _writeDeclareFinalType(indent, module, api.name);
-
     indent.newln();
     _writeObjectStruct(indent, module, api.name, () {
       indent.writeln('const ${className}VTable* vtable;');

packages/pigeon/platform_tests/test_plugin/linux/pigeon/core_tests.gen.cc

@@ -2397,11 +2397,6 @@ core_tests_pigeon_test_test_message_new_from_list(FlValue* values) {
   return core_tests_pigeon_test_test_message_new(test_list);
 }
 
-G_DECLARE_FINAL_TYPE(CoreTestsPigeonTestMessageCodec,
-                     core_tests_pigeon_test_message_codec,
-                     CORE_TESTS_PIGEON_TEST, MESSAGE_CODEC,
-                     FlStandardMessageCodec)
-
 struct _CoreTestsPigeonTestMessageCodec {
   FlStandardMessageCodec parent_instance;
 };
@@ -13564,10 +13559,6 @@ core_tests_pigeon_test_host_integration_core_api_call_flutter_small_api_echo_str
   return self;
 }
 
-G_DECLARE_FINAL_TYPE(CoreTestsPigeonTestHostIntegrationCoreApi,
-                     core_tests_pigeon_test_host_integration_core_api,
-                     CORE_TESTS_PIGEON_TEST, HOST_INTEGRATION_CORE_API, GObject)
-
 struct _CoreTestsPigeonTestHostIntegrationCoreApi {
   GObject parent_instance;
 
@@ -32742,10 +32733,6 @@ core_tests_pigeon_test_host_trivial_api_noop_response_new_error(
   return self;
 }
 
-G_DECLARE_FINAL_TYPE(CoreTestsPigeonTestHostTrivialApi,
-                     core_tests_pigeon_test_host_trivial_api,
-                     CORE_TESTS_PIGEON_TEST, HOST_TRIVIAL_API, GObject)
-
 struct _CoreTestsPigeonTestHostTrivialApi {
   GObject parent_instance;
 
@@ -33021,10 +33008,6 @@ core_tests_pigeon_test_host_small_api_void_void_response_new_error(
   return self;
 }
 
-G_DECLARE_FINAL_TYPE(CoreTestsPigeonTestHostSmallApi,
-                     core_tests_pigeon_test_host_small_api,
-                     CORE_TESTS_PIGEON_TEST, HOST_SMALL_API, GObject)
-
 struct _CoreTestsPigeonTestHostSmallApi {
   GObject parent_instance;
 

packages/pigeon/platform_tests/test_plugin/linux/pigeon/core_tests.gen.h

@@ -1428,6 +1428,15 @@ CoreTestsPigeonTestTestMessage* core_tests_pigeon_test_test_message_new(
 FlValue* core_tests_pigeon_test_test_message_get_test_list(
     CoreTestsPigeonTestTestMessage* object);
 
+G_DECLARE_FINAL_TYPE(CoreTestsPigeonTestMessageCodec,
+                     core_tests_pigeon_test_message_codec,
+                     CORE_TESTS_PIGEON_TEST, MESSAGE_CODEC,
+                     FlStandardMessageCodec)
+
+G_DECLARE_FINAL_TYPE(CoreTestsPigeonTestHostIntegrationCoreApi,
+                     core_tests_pigeon_test_host_integration_core_api,
+                     CORE_TESTS_PIGEON_TEST, HOST_INTEGRATION_CORE_API, GObject)
+
 G_DECLARE_FINAL_TYPE(
     CoreTestsPigeonTestHostIntegrationCoreApiResponseHandle,
     core_tests_pigeon_test_host_integration_core_api_response_handle,
@@ -11869,6 +11878,10 @@ core_tests_pigeon_test_flutter_integration_core_api_echo_async_string_finish(
     CoreTestsPigeonTestFlutterIntegrationCoreApi* api, GAsyncResult* result,
     GError** error);
 
+G_DECLARE_FINAL_TYPE(CoreTestsPigeonTestHostTrivialApi,
+                     core_tests_pigeon_test_host_trivial_api,
+                     CORE_TESTS_PIGEON_TEST, HOST_TRIVIAL_API, GObject)
+
 G_DECLARE_FINAL_TYPE(CoreTestsPigeonTestHostTrivialApiNoopResponse,
                      core_tests_pigeon_test_host_trivial_api_noop_response,
                      CORE_TESTS_PIGEON_TEST, HOST_TRIVIAL_API_NOOP_RESPONSE,
@@ -11936,6 +11949,10 @@ void core_tests_pigeon_test_host_trivial_api_set_method_handlers(
 void core_tests_pigeon_test_host_trivial_api_clear_method_handlers(
     FlBinaryMessenger* messenger, const gchar* suffix);
 
+G_DECLARE_FINAL_TYPE(CoreTestsPigeonTestHostSmallApi,
+                     core_tests_pigeon_test_host_small_api,
+                     CORE_TESTS_PIGEON_TEST, HOST_SMALL_API, GObject)
+
 G_DECLARE_FINAL_TYPE(CoreTestsPigeonTestHostSmallApiResponseHandle,
                      core_tests_pigeon_test_host_small_api_response_handle,
                      CORE_TESTS_PIGEON_TEST, HOST_SMALL_API_RESPONSE_HANDLE,

packages/pigeon/pubspec.yaml

@@ -2,7 +2,7 @@ name: pigeon
 description: Code generator tool to make communication between Flutter and the host platform type-safe and easier.
 repository: https://github.com/flutter/packages/tree/main/packages/pigeon
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+pigeon%22
-version: 22.6.0 # This must match the version in lib/generator_tools.dart
+version: 22.6.1 # This must match the version in lib/generator_tools.dart
 
 environment:
   sdk: ^3.3.0

packages/pigeon/test/gobject_generator_test.dart

@@ -95,6 +95,10 @@ void main() {
           code,
           contains(
               'static void test_package_api_init(TestPackageApi* self) {'));
+      // See https://github.com/flutter/flutter/issues/153083. If a private type
+      // is ever needed, this should be updated to ensure that any type declared
+      // in the implementation file has a corresponding _IS_ call in the file.
+      expect(code, isNot(contains('G_DECLARE_FINAL_TYPE(')));
     }
   });