pkgs/ffigen/lib/src/code_generator/objc_interface.dart - native.git - Git at Google

 // Copyright (c) 2022, the Dart project authors. Please see the AUTHORS file
 // 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 'package:ffigen/src/code_generator.dart';

 import 'binding_string.dart';
 import 'utils.dart';
 import 'writer.dart';

 // Class methods defined on NSObject that we don't want to copy to child objects
 // by default.
 const _excludedNSObjectClassMethods = {
   'allocWithZone:',
   'copyWithZone:',
   'mutableCopyWithZone:',
   'instancesRespondToSelector:',
   'conformsToProtocol:',
   'instanceMethodForSelector:',
   'instanceMethodSignatureForSelector:',
   'isSubclassOfClass:',
   'resolveClassMethod:',
   'resolveInstanceMethod:',
   'hash',
   'superclass',
   'class',
   'description',
   'debugDescription',
 };

 class _ObjCBuiltInFunctions {
   late final _registerNameFunc = Func(
     name: '_sel_registerName',
     originalName: 'sel_registerName',
     returnType: Type.pointer(Type.struct(objCSelType)),
     parameters: [
       Parameter(name: 'str', type: Type.pointer(Type.importedType(charType)))
     ],
   );
   late final String registerName;

   late final _getClassFunc = Func(
     name: '_objc_getClass',
     originalName: 'objc_getClass',
     returnType: Type.pointer(Type.struct(objCObjectType)),
     parameters: [
       Parameter(name: 'str', type: Type.pointer(Type.importedType(charType)))
     ],
   );
   late final String getClass;

   // We need to load a separate instance of objc_msgSend for each signature.
   final _msgSendFuncs = <String, Func>{};
   Func getMsgSendFunc(Type returnType, List<ObjCMethodParam> params) {
     // TODO(#279): These keys don't dedupe sufficiently.
     var key = returnType.hashCode.toRadixString(36);
     for (final p in params) {
       key += ' ' + p.type.hashCode.toRadixString(36);
     }
     _msgSendFuncs[key] ??= Func(
       name: '_objc_msgSend_${_msgSendFuncs.length}',
       originalName: 'objc_msgSend',
       returnType: returnType,
       parameters: [
         Parameter(name: 'obj', type: Type.pointer(Type.struct(objCObjectType))),
         Parameter(name: 'sel', type: Type.pointer(Type.struct(objCSelType))),
         for (final p in params) Parameter(name: p.name, type: p.type.type),
       ],
     );
     return _msgSendFuncs[key]!;
   }

   bool utilsExist = false;
   void ensureUtilsExist(Writer w, StringBuffer s) {
     if (utilsExist) return;
     utilsExist = true;

     registerName = w.topLevelUniqueNamer.makeUnique('_registerName');
     final selType = _registerNameFunc.functionType.returnType.getCType(w);
     s.write('\n$selType $registerName(${w.className} _lib, String name) {\n');
     s.write('  final cstr = name.toNativeUtf8();\n');
     s.write('  final sel = _lib.${_registerNameFunc.name}(cstr.cast());\n');
     s.write('  ${w.ffiPkgLibraryPrefix}.calloc.free(cstr);\n');
     s.write('  return sel;\n');
     s.write('}\n');

     getClass = w.topLevelUniqueNamer.makeUnique('_getClass');
     final objType = _getClassFunc.functionType.returnType.getCType(w);
     s.write('\n$objType $getClass(${w.className} _lib, String name) {\n');
     s.write('  final cstr = name.toNativeUtf8();\n');
     s.write('  final clazz = _lib.${_getClassFunc.name}(cstr.cast());\n');
     s.write('  ${w.ffiPkgLibraryPrefix}.calloc.free(cstr);\n');
     s.write('  return clazz;\n');
     s.write('}\n');

     s.write('\nclass _ObjCWrapper {\n');
     s.write('  final $objType _id;\n');
     s.write('  final ${w.className} _lib;\n');
     s.write('  _ObjCWrapper._(this._id, this._lib);\n');
     s.write('}\n');
   }

   void addDependencies(Set<Binding> dependencies) {
     _registerNameFunc.addDependencies(dependencies);
     _getClassFunc.addDependencies(dependencies);
     for (final func in _msgSendFuncs.values) {
       func.addDependencies(dependencies);
     }
   }
 }

 final _builtInFunctions = _ObjCBuiltInFunctions();

 class ObjCInterface extends NoLookUpBinding {
   ObjCInterface? superType;
   final methods = <ObjCMethod>[];
   bool filled = false;

   // Objective C supports overriding class methods, but Dart doesn't support
   // overriding static methods. So in our generated Dart code, child classes
   // must explicitly implement all the class methods of their super type. To
   // help with this, we store the class methods in this map, as well as in the
   // methods list.
   final classMethods = <String, ObjCMethod>{};

   ObjCInterface({
     String? usr,
     required String originalName,
     required String name,
     String? dartDoc,
   }) : super(
           usr: usr,
           originalName: originalName,
           name: name,
           dartDoc: dartDoc,
         );

   @override
   BindingString toBindingString(Writer w) {
     final s = StringBuffer();
     if (dartDoc != null) {
       s.write(makeDartDoc(dartDoc!));
     }

     final uniqueNamer = UniqueNamer({name});
     final natLib = w.className;

     _builtInFunctions.ensureUtilsExist(w, s);
     final objType = Type.pointer(Type.struct(objCObjectType)).getCType(w);
     final selType = Type.pointer(Type.struct(objCSelType)).getCType(w);

     // Class declaration.
     s.write('class $name ');
     uniqueNamer.markUsed('_id');
     s.write('extends ${superType?.name ?? '_ObjCWrapper'} {\n');
     s.write('  $name._($objType id, $natLib lib) : super._(id, lib);\n\n');

     // Class object, used to call static methods.
     final classObject = uniqueNamer.makeUnique('_class');
     s.write('  static $objType? $classObject;\n\n');

     // Cast method.
     s.write('  static $name castFrom<T extends _ObjCWrapper>(T other) {\n');
     s.write('    return $name._(other._id, other._lib);\n');
     s.write('  }\n\n');

     // Methods.
     for (final m in methods) {
       final methodName = m._getDartMethodName(uniqueNamer);
       final selName = uniqueNamer.makeUnique('_sel_$methodName');
       final isStatic = m.kind == ObjCMethodKind.classMethod;

       // SEL object for the method.
       s.write('  static $selType? $selName;');

       // The method declaration.
       if (m.dartDoc != null) {
         s.write(makeDartDoc(m.dartDoc!));
       }
       s.write('  ');
       if (isStatic) s.write('static ');
       s.write('${m.returnType!.getConvertedType(w, name)} ');
       if (m.kind == ObjCMethodKind.propertyGetter) s.write('get ');
       if (m.kind == ObjCMethodKind.propertySetter) s.write('set ');
       s.write(methodName);
       if (m.kind != ObjCMethodKind.propertyGetter) {
         s.write('(');
         var first = true;
         if (isStatic) {
           first = false;
           s.write('$natLib _lib');
         }
         for (final p in m.params) {
           if (first) {
             first = false;
           } else {
             s.write(', ');
           }
           s.write('${p.type.getConvertedType(w, name)} ${p.name}');
         }
         s.write(')');
       }
       s.write(' {\n');

       // Implementation.
       if (isStatic) {
         s.write('    $classObject ??= '
             '${_builtInFunctions.getClass}(_lib, "$originalName");\n');
       }
       s.write('    $selName ??= '
           '${_builtInFunctions.registerName}(_lib, "${m.originalName}");\n');
       final convertReturn = m.returnType!.needsConverting;
       s.write('    ${convertReturn ? 'final _ret = ' : 'return '}');
       s.write('_lib.${m.msgSend!.name}(');
       s.write(isStatic ? '_class!' : '_id');
       s.write(', $selName!');
       for (final p in m.params) {
         s.write(', ${p.type.doArgConversion(p.name)}');
       }
       s.write(');\n');
       if (convertReturn) {
         final result = m.returnType!.doReturnConversion('_ret', name, '_lib');
         s.write('    return $result;');
       }

       s.write('  }\n\n');
     }

     s.write('}\n\n');

     return BindingString(
         type: BindingStringType.objcInterface, string: s.toString());
   }

   @override
   void addDependencies(Set<Binding> dependencies) {
     if (dependencies.contains(this)) return;
     dependencies.add(this);

     if (superType != null) {
       superType!.addDependencies(dependencies);
       // Copy class methods from the super type, because Dart classes don't
       // inherit static methods.
       for (final m in superType!.classMethods.values) {
         if (!_excludedNSObjectClassMethods.contains(m.originalName)) {
           addMethod(m);
         }
       }
     }

     for (final m in methods) {
       m.addDependencies(dependencies);
     }

     _builtInFunctions.addDependencies(dependencies);
   }

   void addMethod(ObjCMethod method) {
     methods.add(method);
     if (method.kind == ObjCMethodKind.classMethod) {
       classMethods[method.originalName] ??= method;
     }
   }
 }

 enum ObjCMethodKind {
   instanceMethod,
   classMethod,
   propertyGetter,
   propertySetter,
 }

 class ObjCProperty {
   final String originalName;
   String? dartName;
   ObjCProperty(this.originalName);
 }

 class ObjCMethod {
   final String? dartDoc;
   final String originalName;
   final ObjCProperty? property;
   ObjCMethodType? returnType;
   final params = <ObjCMethodParam>[];
   final ObjCMethodKind kind;
   Func? msgSend;

   ObjCMethod({
     required this.originalName,
     this.property,
     this.dartDoc,
     required this.kind,
   });

   void addDependencies(Set<Binding> dependencies) {
     returnType!.type.addDependencies(dependencies);
     for (final p in params) {
       p.type.type.addDependencies(dependencies);
     }
     msgSend = _builtInFunctions.getMsgSendFunc(returnType!.type, params);
   }

   String _getDartMethodName(UniqueNamer uniqueNamer) {
     if (property != null) {
       // A getter and a setter are allowed to have the same name, so we can't
       // just run the name through uniqueNamer. Instead they need to share
       // the dartName, which is run through uniqueNamer.
       if (property!.dartName == null) {
         property!.dartName = uniqueNamer.makeUnique(property!.originalName);
       }
       return property!.dartName!;
     }
     // Objective C methods can look like:
     // foo
     // foo:
     // foo:someArgName:
     // If there is a trailing ':', omit it. Replace all other ':' with '_'.
     var name = originalName;
     final index = name.indexOf(':');
     if (index != -1) name = name.substring(0, index);
     return uniqueNamer.makeUnique(name.replaceAll(':', '_'));
   }
 }

 class ObjCMethodParam {
   final ObjCMethodType type;
   final String name;
   ObjCMethodParam(Type t, this.name) : type = ObjCMethodType(t);
 }

 // Wrapper around Type with helper methods for converting between the internal
 // types passed to native code, and the external types visible to the user. For
 // example, ObjCInterfaces are passed to native as Pointer<ObjCObject>, but the
 // user sees the Dart wrapper class.
 class ObjCMethodType {
   final Type type;
   ObjCMethodType(this.type);

   bool get isObject {
     if (type.broadType != BroadType.Pointer) return false;
     final child = type.child!;
     if (child.broadType != BroadType.Compound) return false;
     return child.compound == objCObjectType;
   }

   bool get isInstanceType {
     if (type.broadType != BroadType.Typealias) return false;
     final alias = type.typealias!;
     if (alias.name != 'instancetype') return false;
     return ObjCMethodType(alias.type).isObject;
   }

   bool get isInterface => type.broadType == BroadType.ObjCInterface;
   bool get isBool => type.broadType == BroadType.Boolean;
   bool get needsConverting =>
       isInterface || isBool || isObject || isInstanceType;

   String getConvertedType(Writer w, String enclosingClass) {
     if (isBool) return 'bool';
     if (isInterface) return type.objCInterface!.name;
     if (isObject) return 'NSObject';
     if (isInstanceType) return enclosingClass;
     return type.getDartType(w);
   }

   String doArgConversion(String value) {
     if (isBool) return '$value ? 1 : 0';
     if (isInterface || isObject || isInstanceType) return '$value._id';
     return value;
   }

   String doReturnConversion(
       String value, String enclosingClass, String library) {
     if (isBool) return '$value != 0';
     if (isInterface) return '${type.objCInterface!.name}._($value, $library)';
     if (isObject) return 'NSObject._($value, $library)';
     if (isInstanceType) return '$enclosingClass._($value, $library)';
     return value;
   }
 }
	// Copyright (c) 2022, the Dart project authors. Please see the AUTHORS file
	// 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 'package:ffigen/src/code_generator.dart';

	import 'binding_string.dart';
	import 'utils.dart';
	import 'writer.dart';

	// Class methods defined on NSObject that we don't want to copy to child objects
	// by default.
	const _excludedNSObjectClassMethods = {
	'allocWithZone:',
	'copyWithZone:',
	'mutableCopyWithZone:',
	'instancesRespondToSelector:',
	'conformsToProtocol:',
	'instanceMethodForSelector:',
	'instanceMethodSignatureForSelector:',
	'isSubclassOfClass:',
	'resolveClassMethod:',
	'resolveInstanceMethod:',
	'hash',
	'superclass',
	'class',
	'description',
	'debugDescription',
	};

	class _ObjCBuiltInFunctions {
	late final _registerNameFunc = Func(
	name: '_sel_registerName',
	originalName: 'sel_registerName',
	returnType: Type.pointer(Type.struct(objCSelType)),
	parameters: [
	Parameter(name: 'str', type: Type.pointer(Type.importedType(charType)))
	],
	);
	late final String registerName;

	late final _getClassFunc = Func(
	name: '_objc_getClass',
	originalName: 'objc_getClass',
	returnType: Type.pointer(Type.struct(objCObjectType)),
	parameters: [
	Parameter(name: 'str', type: Type.pointer(Type.importedType(charType)))
	],
	);
	late final String getClass;

	// We need to load a separate instance of objc_msgSend for each signature.
	final _msgSendFuncs = <String, Func>{};
	Func getMsgSendFunc(Type returnType, List<ObjCMethodParam> params) {
	// TODO(#279): These keys don't dedupe sufficiently.
	var key = returnType.hashCode.toRadixString(36);
	for (final p in params) {
	key += ' ' + p.type.hashCode.toRadixString(36);
	}
	_msgSendFuncs[key] ??= Func(
	name: '_objc_msgSend_${_msgSendFuncs.length}',
	originalName: 'objc_msgSend',
	returnType: returnType,
	parameters: [
	Parameter(name: 'obj', type: Type.pointer(Type.struct(objCObjectType))),
	Parameter(name: 'sel', type: Type.pointer(Type.struct(objCSelType))),
	for (final p in params) Parameter(name: p.name, type: p.type.type),
	],
	);
	return _msgSendFuncs[key]!;
	}

	bool utilsExist = false;
	void ensureUtilsExist(Writer w, StringBuffer s) {
	if (utilsExist) return;
	utilsExist = true;

	registerName = w.topLevelUniqueNamer.makeUnique('_registerName');
	final selType = _registerNameFunc.functionType.returnType.getCType(w);
	s.write('\n$selType $registerName(${w.className} _lib, String name) {\n');
	s.write(' final cstr = name.toNativeUtf8();\n');
	s.write(' final sel = _lib.${_registerNameFunc.name}(cstr.cast());\n');
	s.write(' ${w.ffiPkgLibraryPrefix}.calloc.free(cstr);\n');
	s.write(' return sel;\n');
	s.write('}\n');

	getClass = w.topLevelUniqueNamer.makeUnique('_getClass');
	final objType = _getClassFunc.functionType.returnType.getCType(w);
	s.write('\n$objType $getClass(${w.className} _lib, String name) {\n');
	s.write(' final cstr = name.toNativeUtf8();\n');
	s.write(' final clazz = _lib.${_getClassFunc.name}(cstr.cast());\n');
	s.write(' ${w.ffiPkgLibraryPrefix}.calloc.free(cstr);\n');
	s.write(' return clazz;\n');
	s.write('}\n');

	s.write('\nclass _ObjCWrapper {\n');
	s.write(' final $objType _id;\n');
	s.write(' final ${w.className} _lib;\n');
	s.write(' _ObjCWrapper._(this._id, this._lib);\n');
	s.write('}\n');
	}

	void addDependencies(Set<Binding> dependencies) {
	_registerNameFunc.addDependencies(dependencies);
	_getClassFunc.addDependencies(dependencies);
	for (final func in _msgSendFuncs.values) {
	func.addDependencies(dependencies);
	}
	}
	}

	final _builtInFunctions = _ObjCBuiltInFunctions();

	class ObjCInterface extends NoLookUpBinding {
	ObjCInterface? superType;
	final methods = <ObjCMethod>[];
	bool filled = false;

	// Objective C supports overriding class methods, but Dart doesn't support
	// overriding static methods. So in our generated Dart code, child classes
	// must explicitly implement all the class methods of their super type. To
	// help with this, we store the class methods in this map, as well as in the
	// methods list.
	final classMethods = <String, ObjCMethod>{};

	ObjCInterface({
	String? usr,
	required String originalName,
	required String name,
	String? dartDoc,
	}) : super(
	usr: usr,
	originalName: originalName,
	name: name,
	dartDoc: dartDoc,
	);

	@override
	BindingString toBindingString(Writer w) {
	final s = StringBuffer();
	if (dartDoc != null) {
	s.write(makeDartDoc(dartDoc!));
	}

	final uniqueNamer = UniqueNamer({name});
	final natLib = w.className;

	_builtInFunctions.ensureUtilsExist(w, s);
	final objType = Type.pointer(Type.struct(objCObjectType)).getCType(w);
	final selType = Type.pointer(Type.struct(objCSelType)).getCType(w);

	// Class declaration.
	s.write('class $name ');
	uniqueNamer.markUsed('_id');
	s.write('extends ${superType?.name ?? '_ObjCWrapper'} {\n');
	s.write(' $name._($objType id, $natLib lib) : super._(id, lib);\n\n');

	// Class object, used to call static methods.
	final classObject = uniqueNamer.makeUnique('_class');
	s.write(' static $objType? $classObject;\n\n');

	// Cast method.
	s.write(' static $name castFrom<T extends _ObjCWrapper>(T other) {\n');
	s.write(' return $name._(other._id, other._lib);\n');
	s.write(' }\n\n');

	// Methods.
	for (final m in methods) {
	final methodName = m._getDartMethodName(uniqueNamer);
	final selName = uniqueNamer.makeUnique('_sel_$methodName');
	final isStatic = m.kind == ObjCMethodKind.classMethod;

	// SEL object for the method.
	s.write(' static $selType? $selName;');

	// The method declaration.
	if (m.dartDoc != null) {
	s.write(makeDartDoc(m.dartDoc!));
	}
	s.write(' ');
	if (isStatic) s.write('static ');
	s.write('${m.returnType!.getConvertedType(w, name)} ');
	if (m.kind == ObjCMethodKind.propertyGetter) s.write('get ');
	if (m.kind == ObjCMethodKind.propertySetter) s.write('set ');
	s.write(methodName);
	if (m.kind != ObjCMethodKind.propertyGetter) {
	s.write('(');
	var first = true;
	if (isStatic) {
	first = false;
	s.write('$natLib _lib');
	}
	for (final p in m.params) {
	if (first) {
	first = false;
	} else {
	s.write(', ');
	}
	s.write('${p.type.getConvertedType(w, name)} ${p.name}');
	}
	s.write(')');
	}
	s.write(' {\n');

	// Implementation.
	if (isStatic) {
	s.write(' $classObject ??= '
	'${_builtInFunctions.getClass}(_lib, "$originalName");\n');
	}
	s.write(' $selName ??= '
	'${_builtInFunctions.registerName}(_lib, "${m.originalName}");\n');
	final convertReturn = m.returnType!.needsConverting;
	s.write(' ${convertReturn ? 'final _ret = ' : 'return '}');
	s.write('_lib.${m.msgSend!.name}(');
	s.write(isStatic ? '_class!' : '_id');
	s.write(', $selName!');
	for (final p in m.params) {
	s.write(', ${p.type.doArgConversion(p.name)}');
	}
	s.write(');\n');
	if (convertReturn) {
	final result = m.returnType!.doReturnConversion('_ret', name, '_lib');
	s.write(' return $result;');
	}

	s.write(' }\n\n');
	}

	s.write('}\n\n');

	return BindingString(
	type: BindingStringType.objcInterface, string: s.toString());
	}

	@override
	void addDependencies(Set<Binding> dependencies) {
	if (dependencies.contains(this)) return;
	dependencies.add(this);

	if (superType != null) {
	superType!.addDependencies(dependencies);
	// Copy class methods from the super type, because Dart classes don't
	// inherit static methods.
	for (final m in superType!.classMethods.values) {
	if (!_excludedNSObjectClassMethods.contains(m.originalName)) {
	addMethod(m);
	}
	}
	}

	for (final m in methods) {
	m.addDependencies(dependencies);
	}

	_builtInFunctions.addDependencies(dependencies);
	}

	void addMethod(ObjCMethod method) {
	methods.add(method);
	if (method.kind == ObjCMethodKind.classMethod) {
	classMethods[method.originalName] ??= method;
	}
	}
	}

	enum ObjCMethodKind {
	instanceMethod,
	classMethod,
	propertyGetter,
	propertySetter,
	}

	class ObjCProperty {
	final String originalName;
	String? dartName;
	ObjCProperty(this.originalName);
	}

	class ObjCMethod {
	final String? dartDoc;
	final String originalName;
	final ObjCProperty? property;
	ObjCMethodType? returnType;
	final params = <ObjCMethodParam>[];
	final ObjCMethodKind kind;
	Func? msgSend;

	ObjCMethod({
	required this.originalName,
	this.property,
	this.dartDoc,
	required this.kind,
	});

	void addDependencies(Set<Binding> dependencies) {
	returnType!.type.addDependencies(dependencies);
	for (final p in params) {
	p.type.type.addDependencies(dependencies);
	}
	msgSend = _builtInFunctions.getMsgSendFunc(returnType!.type, params);
	}

	String _getDartMethodName(UniqueNamer uniqueNamer) {
	if (property != null) {
	// A getter and a setter are allowed to have the same name, so we can't
	// just run the name through uniqueNamer. Instead they need to share
	// the dartName, which is run through uniqueNamer.
	if (property!.dartName == null) {
	property!.dartName = uniqueNamer.makeUnique(property!.originalName);
	}
	return property!.dartName!;
	}
	// Objective C methods can look like:
	// foo
	// foo:
	// foo:someArgName:
	// If there is a trailing ':', omit it. Replace all other ':' with '_'.
	var name = originalName;
	final index = name.indexOf(':');
	if (index != -1) name = name.substring(0, index);
	return uniqueNamer.makeUnique(name.replaceAll(':', '_'));
	}
	}

	class ObjCMethodParam {
	final ObjCMethodType type;
	final String name;
	ObjCMethodParam(Type t, this.name) : type = ObjCMethodType(t);
	}

	// Wrapper around Type with helper methods for converting between the internal
	// types passed to native code, and the external types visible to the user. For
	// example, ObjCInterfaces are passed to native as Pointer<ObjCObject>, but the
	// user sees the Dart wrapper class.
	class ObjCMethodType {
	final Type type;
	ObjCMethodType(this.type);

	bool get isObject {
	if (type.broadType != BroadType.Pointer) return false;
	final child = type.child!;
	if (child.broadType != BroadType.Compound) return false;
	return child.compound == objCObjectType;
	}

	bool get isInstanceType {
	if (type.broadType != BroadType.Typealias) return false;
	final alias = type.typealias!;
	if (alias.name != 'instancetype') return false;
	return ObjCMethodType(alias.type).isObject;
	}

	bool get isInterface => type.broadType == BroadType.ObjCInterface;
	bool get isBool => type.broadType == BroadType.Boolean;
	bool get needsConverting =>
	isInterface \|\| isBool \|\| isObject \|\| isInstanceType;

	String getConvertedType(Writer w, String enclosingClass) {
	if (isBool) return 'bool';
	if (isInterface) return type.objCInterface!.name;
	if (isObject) return 'NSObject';
	if (isInstanceType) return enclosingClass;
	return type.getDartType(w);
	}

	String doArgConversion(String value) {
	if (isBool) return '$value ? 1 : 0';
	if (isInterface \|\| isObject \|\| isInstanceType) return '$value._id';
	return value;
	}

	String doReturnConversion(
	String value, String enclosingClass, String library) {
	if (isBool) return '$value != 0';
	if (isInterface) return '${type.objCInterface!.name}._($value, $library)';
	if (isObject) return 'NSObject._($value, $library)';
	if (isInstanceType) return '$enclosingClass._($value, $library)';
	return value;
	}
	}