[ffigen] Fix protocol inclusion rules

pkgs/ffigen/CHANGELOG.md

@@ -4,6 +4,12 @@
 - ObjC objects now include the methods from the protocols they implement. Both
   required and optional methods are included. Optional methods will throw an
   exception if the method isn't implemented.
+- __Breaking change__: Only generate ObjC protocol implementation bindings for
+  protocols that are included by the config filters. This is breaking because
+  previously super protocols would automatically get implementation bindings,
+  rather than just being incorporated into the child protocol. If you want those
+  implementation bindings, you may need to add the super protocol to your
+  `objc-protocols` filters.
 
 ## 14.0.1
 

pkgs/ffigen/lib/src/code_generator/objc_protocol.dart

@@ -12,6 +12,7 @@ class ObjCProtocol extends NoLookUpBinding with ObjCMethods {
   final superProtocols = <ObjCProtocol>[];
   final String lookupName;
   late final ObjCInternalGlobal _protocolPointer;
+  final bool generateBindings;
 
   @override
   final ObjCBuiltInFunctions builtInFunctions;
@@ -23,11 +24,17 @@ class ObjCProtocol extends NoLookUpBinding with ObjCMethods {
     String? lookupName,
     super.dartDoc,
     required this.builtInFunctions,
+    required this.generateBindings,
   })  : lookupName = lookupName ?? originalName,
         super(name: name ?? originalName);
 
   @override
   BindingString toBindingString(Writer w) {
+    if (!generateBindings) {
+      return const BindingString(
+          type: BindingStringType.objcProtocol, string: '');
+    }
+
     final protocolMethod = ObjCBuiltInFunctions.protocolMethod.gen(w);
     final protocolListenableMethod =
         ObjCBuiltInFunctions.protocolListenableMethod.gen(w);
@@ -154,11 +161,13 @@ ${makeDartDoc(dartDoc ?? originalName)}abstract final class $name {
     if (dependencies.contains(this)) return;
     dependencies.add(this);
 
-    _protocolPointer = ObjCInternalGlobal(
-        '_protocol_$originalName',
-        (Writer w) =>
-            '${ObjCBuiltInFunctions.getProtocol.gen(w)}("$lookupName")')
-      ..addDependencies(dependencies);
+    if (generateBindings) {
+      _protocolPointer = ObjCInternalGlobal(
+          '_protocol_$originalName',
+          (Writer w) =>
+              '${ObjCBuiltInFunctions.getProtocol.gen(w)}("$lookupName")')
+        ..addDependencies(dependencies);
+    }
 
     for (final superProtocol in superProtocols) {
       superProtocol.addDependencies(dependencies);

pkgs/ffigen/lib/src/header_parser/sub_parsers/objcinterfacedecl_parser.dart

@@ -118,7 +118,7 @@ void _parseSuperType(clang_types.CXCursor cursor, ObjCInterface itf) {
 
 void _parseProtocol(clang_types.CXCursor cursor, ObjCInterface itf) {
   final protoCursor = clang.clang_getCursorDefinition(cursor);
-  final proto = parseObjCProtocolDeclaration(protoCursor);
+  final proto = parseObjCProtocolDeclaration(protoCursor, ignoreFilter: true);
   if (proto != null) {
     itf.addProtocol(proto);
   }

pkgs/ffigen/lib/src/header_parser/sub_parsers/objcprotocoldecl_parser.dart

@@ -22,18 +22,19 @@ ObjCProtocol? parseObjCProtocolDeclaration(clang_types.CXCursor cursor,
   }
 
   final usr = cursor.usr();
-  final cachedProtocol = bindingsIndex.getSeenObjCProtocol(usr);
-  if (cachedProtocol != null) {
-    return cachedProtocol;
-  }
-
   final name = cursor.spelling();
 
   final decl = Declaration(usr: usr, originalName: name);
-  if (!ignoreFilter && !shouldIncludeObjCProtocol(decl)) {
+  final included = shouldIncludeObjCProtocol(decl);
+  if (!ignoreFilter && !included) {
     return null;
   }
 
+  final cachedProtocol = bindingsIndex.getSeenObjCProtocol(usr);
+  if (cachedProtocol != null) {
+    return cachedProtocol;
+  }
+
   if (!isApiAvailable(cursor)) {
     _logger.info('Omitting deprecated protocol $name');
     return null;
@@ -49,6 +50,12 @@ ObjCProtocol? parseObjCProtocolDeclaration(clang_types.CXCursor cursor,
     lookupName: applyModulePrefix(name, config.protocolModule(decl)),
     dartDoc: getCursorDocComment(cursor),
     builtInFunctions: objCBuiltInFunctions,
+
+    // Only generate bindings for the protocol if it is included in the user's
+    // filters. If this protocol was only parsed because of ignoreFilter, then
+    // it's being used to add methods to an interface or a child protocol, and
+    // shouldn't get bindings.
+    generateBindings: included,
   );
 
   // Make sure to add the protocol to the index before parsing the AST, to break

pkgs/ffigen/test/native_objc_test/protocol_test.dart

@@ -70,6 +70,9 @@ void main() {
         // Required instance method from secondary protocol.
         final otherIntResult = protocolImpl.otherMethod_b_c_d_(2, 4, 6, 8);
         expect(otherIntResult, 20);
+
+        // Method from a protocol that isn't included by the filters.
+        expect(protocolImpl.fooMethod(), 2468);
       });
 
       test('Unimplemented method', () {
@@ -373,5 +376,23 @@ void main() {
         expect(blockRetainCount(blockPtr), 0);
       }, skip: !canDoGC);
     });
+
+    test('Filters', () {
+      // SuperProtocol and FilteredProtocol's methods are included in the
+      // bindings, but there shouldn't actually be bindings for the protocols
+      // themselves, because they're not included by the config.
+      final bindings = File('test/native_objc_test/protocol_bindings.dart')
+          .readAsStringSync();
+
+      expect(bindings, contains('instanceMethod_withDouble_'));
+      expect(bindings, contains('fooMethod'));
+
+      expect(bindings, contains('EmptyProtocol'));
+      expect(bindings, contains('MyProtocol'));
+      expect(bindings, contains('SecondaryProtocol'));
+
+      expect(bindings, isNot(contains('SuperProtocol')));
+      expect(bindings, isNot(contains('FilteredProtocol')));
+    });
   });
 }

pkgs/ffigen/test/native_objc_test/protocol_test.h

@@ -43,6 +43,11 @@ typedef struct {
 @protocol EmptyProtocol
 @end
 
+@protocol FilteredProtocol
+@required
+- (int32_t)fooMethod;
+@end
+
 
 @interface ProtocolConsumer : NSObject
 - (NSString*)callInstanceMethod:(id<MyProtocol>)protocol;
@@ -52,7 +57,8 @@ typedef struct {
 @end
 
 
-@interface ObjCProtocolImpl : NSObject<MyProtocol, SecondaryProtocol>
+@interface ObjCProtocolImpl :
+    NSObject<MyProtocol, SecondaryProtocol, FilteredProtocol>
 @end
 
 

pkgs/ffigen/test/native_objc_test/protocol_test.m

@@ -46,6 +46,10 @@ - (int32_t)otherMethod:(int32_t)a b:(int32_t)b c:(int32_t)c d:(int32_t)d {
   return a + b + c + d;
 }
 
+- (int32_t)fooMethod {
+  return 2468;
+}
+
 @end