ObjC static functions

CHANGELOG.md

@@ -9,6 +9,7 @@
 - When generating typedefs for `Pointer<NativeFunction<Function>>`, also
   generate a typedef for the `Function`.
 - Use Dart wrapper types in args and returns of ObjCBlocks.
+- Use Dart wrapper types in args and returns of static functions.
 - Bump min SDK version to 3.2.0-114.0.dev.
 
 # 9.0.1

lib/src/code_generator/func.dart

@@ -42,6 +42,7 @@ class Func extends LookUpBinding {
   final bool exposeSymbolAddress;
   final bool exposeFunctionTypedefs;
   final bool isLeaf;
+  final bool objCReturnsRetained;
   final FfiNativeConfig ffiNativeConfig;
   late final String funcPointerName;
 
@@ -61,6 +62,7 @@ class Func extends LookUpBinding {
     this.exposeSymbolAddress = false,
     this.exposeFunctionTypedefs = false,
     this.isLeaf = false,
+    this.objCReturnsRetained = false,
     super.isInternal,
     this.ffiNativeConfig = const FfiNativeConfig(enabled: false),
   })  : functionType = FunctionType(
@@ -93,8 +95,6 @@ class Func extends LookUpBinding {
   BindingString toBindingString(Writer w) {
     final s = StringBuffer();
     final enclosingFuncName = name;
-    final funcVarName = w.wrapperLevelUniqueNamer.makeUnique('_$name');
-    funcPointerName = w.wrapperLevelUniqueNamer.makeUnique('_${name}Ptr');
 
     if (dartDoc != null) {
       s.write(makeDartDoc(dartDoc!));
@@ -109,37 +109,71 @@ class Func extends LookUpBinding {
         functionType.getCType(w, writeArgumentNames: false);
     final dartType = _exposedFunctionTypealias?.getFfiDartType(w) ??
         functionType.getFfiDartType(w, writeArgumentNames: false);
+    final needsWrapper = !functionType.sameDartAndFfiDartType && !isInternal;
+
+    final isLeafString = isLeaf ? 'isLeaf:true' : '';
+    final funcVarName = w.wrapperLevelUniqueNamer.makeUnique('_$name');
+    final ffiReturnType = functionType.returnType.getFfiDartType(w);
+    final ffiArgDeclString = functionType.dartTypeParameters
+        .map((p) => '${p.type.getFfiDartType(w)} ${p.name},\n')
+        .join('');
+
+    late final String dartReturnType;
+    late final String dartArgDeclString;
+    late final String funcImplCall;
+    if (needsWrapper) {
+      dartReturnType = functionType.returnType.getDartType(w);
+      dartArgDeclString = functionType.dartTypeParameters
+          .map((p) => '${p.type.getDartType(w)} ${p.name},\n')
+          .join('');
+
+      final argString = functionType.dartTypeParameters
+          .map((p) =>
+              '${p.type.convertDartTypeToFfiDartType(w, p.name, objCRetain: false)},\n')
+          .join('');
+      funcImplCall = functionType.returnType.convertFfiDartTypeToDartType(
+        w,
+        '$funcVarName($argString)',
+        ffiNativeConfig.enabled ? 'lib' : 'this',
+        objCRetain: !objCReturnsRetained,
+      );
+    } else {
+      dartReturnType = ffiReturnType;
+      dartArgDeclString = ffiArgDeclString;
+      final argString =
+          functionType.dartTypeParameters.map((p) => '${p.name},\n').join('');
+      funcImplCall = '$funcVarName($argString)';
+    }
 
     if (ffiNativeConfig.enabled) {
       final assetString = ffiNativeConfig.asset != null
           ? ", asset: '${ffiNativeConfig.asset}'"
           : '';
-      final isLeafString = isLeaf ? ', isLeaf: true' : '';
-      s.write(
-          "@${w.ffiLibraryPrefix}.Native<$cType>(symbol: '$originalName'$assetString$isLeafString)\n");
-
-      s.write(
-          'external ${functionType.returnType.getFfiDartType(w)} $enclosingFuncName(\n');
-      for (final p in functionType.dartTypeParameters) {
-        s.write('  ${p.type.getFfiDartType(w)} ${p.name},\n');
+      final nativeFuncName = needsWrapper ? funcVarName : enclosingFuncName;
+      s.write('''
+@${w.ffiLibraryPrefix}.Native<$cType>(symbol: '$originalName'$assetString$isLeafString)
+external $ffiReturnType $nativeFuncName($ffiArgDeclString);
+
+''');
+      if (needsWrapper) {
+        final libArg = functionType.returnType.sameDartAndFfiDartType
+            ? ''
+            : '${w.className} lib, ';
+        s.write('''
+$dartReturnType $enclosingFuncName($libArg$dartArgDeclString) => $funcImplCall;
+
+''');
       }
-      s.write(');\n\n');
     } else {
+      funcPointerName = w.wrapperLevelUniqueNamer.makeUnique('_${name}Ptr');
+
       // Write enclosing function.
-      s.write(
-          '${functionType.returnType.getFfiDartType(w)} $enclosingFuncName(\n');
-      for (final p in functionType.dartTypeParameters) {
-        s.write('  ${p.type.getFfiDartType(w)} ${p.name},\n');
-      }
-      s.write(') {\n');
-      s.write('return $funcVarName');
+      s.write('''
+$dartReturnType $enclosingFuncName($dartArgDeclString) {
+  return $funcImplCall;
+}
 
-      s.write('(\n');
-      for (final p in functionType.dartTypeParameters) {
-        s.write('    ${p.name},\n');
-      }
-      s.write('  );\n');
-      s.write('}\n');
+''');
 
       if (exposeSymbolAddress) {
         // Add to SymbolAddress in writer.
@@ -150,12 +184,14 @@ class Func extends LookUpBinding {
           ptrName: funcPointerName,
         );
       }
+
       // Write function pointer.
-      s.write(
-          "late final $funcPointerName = ${w.lookupFuncIdentifier}<${w.ffiLibraryPrefix}.NativeFunction<$cType>>('$originalName');\n");
-      final isLeafString = isLeaf ? 'isLeaf:true' : '';
-      s.write(
-          'late final $funcVarName = $funcPointerName.asFunction<$dartType>($isLeafString);\n\n');
+      s.write('''
+late final $funcPointerName = ${w.lookupFuncIdentifier}<
+    ${w.ffiLibraryPrefix}.NativeFunction<$cType>>('$originalName');
+late final $funcVarName = $funcPointerName.asFunction<$dartType>($isLeafString);
+
+''');
     }
 
     return BindingString(type: BindingStringType.func, string: s.toString());

lib/src/code_generator/func_type.dart

@@ -78,6 +78,11 @@ class FunctionType extends Type {
       returnType.sameDartAndCType &&
       dartTypeParameters.every((p) => p.type.sameDartAndCType);
 
+  @override
+  bool get sameDartAndFfiDartType =>
+      returnType.sameDartAndFfiDartType &&
+      dartTypeParameters.every((p) => p.type.sameDartAndFfiDartType);
+
   @override
   String toString() => _getTypeImpl(false, (Type t) => t.toString());
 

lib/src/code_generator/objc_block.dart

@@ -228,6 +228,9 @@ _id.ref.invoke.cast<$natTrampFnType>().asFunction<$trampFuncFfiDartType>()(
   @override
   bool get sameDartAndCType => false;
 
+  @override
+  bool get sameDartAndFfiDartType => false;
+
   @override
   String convertDartTypeToFfiDartType(
     Writer w,

lib/src/code_generator/objc_interface.dart

@@ -401,6 +401,9 @@ class $name extends ${superType?.name ?? '_ObjCWrapper'} {
   @override
   bool get sameDartAndCType => false;
 
+  @override
+  bool get sameDartAndFfiDartType => false;
+
   @override
   String convertDartTypeToFfiDartType(
     Writer w,

lib/src/code_generator/objc_nullable.dart

@@ -44,6 +44,9 @@ class ObjCNullable extends Type {
   @override
   bool get sameDartAndCType => false;
 
+  @override
+  bool get sameDartAndFfiDartType => false;
+
   @override
   String convertDartTypeToFfiDartType(
     Writer w,

lib/src/code_generator/pointer.dart

@@ -87,6 +87,9 @@ class ObjCObjectPointer extends PointerType {
   @override
   bool get sameDartAndCType => false;
 
+  @override
+  bool get sameDartAndFfiDartType => false;
+
   @override
   String convertDartTypeToFfiDartType(
     Writer w,

lib/src/code_generator/type.dart

@@ -54,6 +54,9 @@ abstract class Type {
   /// Returns whether the dart type and C type string are same.
   bool get sameDartAndCType => sameFfiDartAndCType;
 
+  /// Returns whether the dart type and FFI dart type string are same.
+  bool get sameDartAndFfiDartType => true;
+
   /// Returns generated Dart code that converts the given value from its
   /// DartType to its FfiDartType.
   ///
@@ -138,6 +141,9 @@ abstract class BindingType extends NoLookUpBinding implements Type {
   @override
   bool get sameDartAndCType => sameFfiDartAndCType;
 
+  @override
+  bool get sameDartAndFfiDartType => true;
+
   @override
   String convertDartTypeToFfiDartType(
     Writer w,

lib/src/code_generator/typealias.dart

@@ -158,6 +158,9 @@ class Typealias extends BindingType {
   @override
   bool get sameDartAndCType => type.sameDartAndCType;
 
+  @override
+  bool get sameDartAndFfiDartType => type.sameDartAndFfiDartType;
+
   @override
   String convertDartTypeToFfiDartType(
     Writer w,

lib/src/header_parser/sub_parsers/functiondecl_parser.dart

@@ -2,6 +2,8 @@
 // for details. 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:ffi';
+
 import 'package:ffigen/src/code_generator.dart';
 import 'package:ffigen/src/config_provider/config_types.dart';
 import 'package:ffigen/src/header_parser/data.dart';
@@ -20,6 +22,7 @@ class _ParserFunc {
   List<Func> funcs = [];
   bool incompleteStructParameter = false;
   bool unimplementedParameterType = false;
+  bool objCReturnsRetained = false;
   _ParserFunc();
 }
 
@@ -69,6 +72,13 @@ List<Func>? parseFunctionDeclaration(clang_types.CXCursor cursor) {
       return _stack.pop().funcs;
     }
 
+    // Look for any annotations on the function.
+    clang.clang_visitChildren(
+        cursor,
+        _parseAnnotationVisitorPtr ??= Pointer.fromFunction(
+            _parseAnnotationVisitor, exceptional_visitor_return),
+        nullptr);
+
     // Initialized with a single value with no prefix and empty var args.
     var varArgFunctions = [VarArgFunction('', [])];
     if (config.varArgFunctions.containsKey(funcName)) {
@@ -97,6 +107,7 @@ List<Func>? parseFunctionDeclaration(clang_types.CXCursor cursor) {
         exposeFunctionTypedefs:
             config.exposeFunctionTypedefs.shouldInclude(funcName),
         isLeaf: config.leafFunctions.shouldInclude(funcName),
+        objCReturnsRetained: _stack.top.objCReturnsRetained,
         ffiNativeConfig: config.ffiNativeConfig,
       ));
     }
@@ -147,3 +158,19 @@ List<Parameter> _getParameters(clang_types.CXCursor cursor, String funcName) {
 Type _getParameterType(clang_types.CXCursor cursor) {
   return cursor.toCodeGenType();
 }
+
+Pointer<
+        NativeFunction<
+            Int32 Function(
+                clang_types.CXCursor, clang_types.CXCursor, Pointer<Void>)>>?
+    _parseAnnotationVisitorPtr;
+int _parseAnnotationVisitor(clang_types.CXCursor cursor,
+    clang_types.CXCursor parent, Pointer<Void> clientData) {
+  switch (cursor.kind) {
+    case clang_types.CXCursorKind.CXCursor_NSReturnsRetained:
+      _stack.top.objCReturnsRetained = true;
+      break;
+    default:
+  }
+  return clang_types.CXChildVisitResult.CXChildVisit_Continue;
+}

test/native_objc_test/automated_ref_count_test.m

@@ -89,12 +89,14 @@ - (ArcTestObject*)returnsRetained NS_RETURNS_RETAINED {
 
 @end
 
-id createAutoreleasePool() {
-  return [NSAutoreleasePool new];
+// Pass around the NSAutoreleasePool as a void* to bypass the Dart wrappers so
+// that we can precisely control the life cycle.
+void* createAutoreleasePool() {
+  return (void*)[NSAutoreleasePool new];
 }
 
-void destroyAutoreleasePool(id pool) {
-  [pool release];
+void destroyAutoreleasePool(void* pool) {
+  [((NSAutoreleasePool*)pool) release];
 }
 
 @implementation RefCounted

test/native_objc_test/block_config.yaml

@@ -6,6 +6,9 @@ exclude-all-by-default: true
 objc-interfaces:
   include:
     - BlockTester
+functions:
+  include:
+    - getBlockRetainCount
 headers:
   entry-points:
     - 'block_test.m'