[swift2objc] Availability annotations (#2476)

Author: liamappelbe

pkgs/swift2objc/lib/src/ast/_core/interfaces/availability.dart

@@ -0,0 +1,38 @@
+// Copyright (c) 2025, 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.
+
+/// A Swift declaration's availability info.
+abstract interface class Availability {
+  abstract final List<AvailabilityInfo> availability;
+}
+
+/// The availability for a single domain.
+class AvailabilityInfo {
+  String domain;
+  bool unavailable;
+  AvailabilityVersion? introduced;
+  AvailabilityVersion? deprecated;
+  AvailabilityVersion? obsoleted;
+
+  AvailabilityInfo({
+    required this.domain,
+    required this.unavailable,
+    required this.introduced,
+    required this.deprecated,
+    required this.obsoleted,
+  });
+}
+
+/// A version for availability.
+class AvailabilityVersion {
+  int major;
+  int? minor;
+  int? patch;
+
+  AvailabilityVersion(
+      {required this.major, required this.minor, required this.patch});
+
+  @override
+  String toString() => [major, minor, patch].nonNulls.join('.');
+}

pkgs/swift2objc/lib/src/ast/_core/interfaces/declaration.dart

@@ -4,9 +4,10 @@
 
 import '../../ast_node.dart';
 import '../shared/referred_type.dart';
+import 'availability.dart';
 
 /// A common interface for all Swift entities declarations.
-abstract interface class Declaration implements AstNode {
+abstract interface class Declaration implements AstNode, Availability {
   abstract final String id;
   abstract final String name;
 }

pkgs/swift2objc/lib/src/ast/declarations/built_in/built_in_declaration.dart

@@ -2,6 +2,7 @@
 // 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 '../../_core/interfaces/availability.dart';
 import '../../_core/interfaces/declaration.dart';
 import '../../_core/interfaces/objc_annotatable.dart';
 import '../../ast_node.dart';
@@ -15,6 +16,9 @@ class BuiltInDeclaration extends AstNode
   @override
   final String name;
 
+  @override
+  List<AvailabilityInfo> get availability => const [];
+
   @override
   bool get hasObjCAnnotation => true;
 

pkgs/swift2objc/lib/src/ast/declarations/compounds/class_declaration.dart

@@ -2,6 +2,7 @@
 // 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 '../../_core/interfaces/availability.dart';
 import '../../_core/interfaces/compound_declaration.dart';
 import '../../_core/interfaces/declaration.dart';
 import '../../_core/interfaces/nestable_declaration.dart';
@@ -23,6 +24,9 @@ class ClassDeclaration extends AstNode
   @override
   String name;
 
+  @override
+  List<AvailabilityInfo> availability;
+
   @override
   covariant List<PropertyDeclaration> properties;
 
@@ -63,6 +67,7 @@ class ClassDeclaration extends AstNode
   ClassDeclaration({
     required this.id,
     required this.name,
+    required this.availability,
     this.properties = const [],
     this.methods = const [],
     this.nestingParent,

pkgs/swift2objc/lib/src/ast/declarations/compounds/members/initializer_declaration.dart

@@ -2,6 +2,7 @@
 // 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 '../../../_core/interfaces/availability.dart';
 import '../../../_core/interfaces/can_async.dart';
 import '../../../_core/interfaces/can_throw.dart';
 import '../../../_core/interfaces/declaration.dart';
@@ -28,6 +29,9 @@ class InitializerDeclaration extends AstNode
   @override
   String get name => 'init';
 
+  @override
+  List<AvailabilityInfo> availability;
+
   @override
   bool hasObjCAnnotation;
 
@@ -55,6 +59,7 @@ class InitializerDeclaration extends AstNode
 
   InitializerDeclaration({
     required this.id,
+    required this.availability,
     required this.params,
     this.statements = const [],
     required this.hasObjCAnnotation,

pkgs/swift2objc/lib/src/ast/declarations/compounds/members/method_declaration.dart

@@ -2,6 +2,7 @@
 // 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 '../../../_core/interfaces/availability.dart';
 import '../../../_core/interfaces/function_declaration.dart';
 import '../../../_core/interfaces/objc_annotatable.dart';
 import '../../../_core/interfaces/overridable.dart';
@@ -19,6 +20,9 @@ class MethodDeclaration extends AstNode
   @override
   String name;
 
+  @override
+  List<AvailabilityInfo> availability;
+
   @override
   List<Parameter> params;
 
@@ -55,6 +59,7 @@ class MethodDeclaration extends AstNode
   MethodDeclaration(
       {required this.id,
       required this.name,
+      required this.availability,
       required this.returnType,
       required this.params,
       this.typeParams = const [],

pkgs/swift2objc/lib/src/ast/declarations/compounds/members/property_declaration.dart

@@ -2,6 +2,7 @@
 // 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 '../../../_core/interfaces/availability.dart';
 import '../../../_core/interfaces/executable.dart';
 import '../../../_core/interfaces/objc_annotatable.dart';
 import '../../../_core/interfaces/variable_declaration.dart';
@@ -18,6 +19,9 @@ class PropertyDeclaration extends AstNode
   @override
   String name;
 
+  @override
+  List<AvailabilityInfo> availability;
+
   @override
   bool hasObjCAnnotation;
 
@@ -51,6 +55,7 @@ class PropertyDeclaration extends AstNode
   PropertyDeclaration(
       {required this.id,
       required this.name,
+      required this.availability,
       required this.type,
       this.hasSetter = false,
       this.isConstant = false,

pkgs/swift2objc/lib/src/ast/declarations/compounds/protocol_declaration.dart

@@ -2,6 +2,7 @@
 // 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 '../../_core/interfaces/availability.dart';
 import '../../_core/interfaces/compound_declaration.dart';
 import '../../_core/interfaces/nestable_declaration.dart';
 import '../../_core/shared/referred_type.dart';
@@ -18,6 +19,9 @@ class ProtocolDeclaration extends AstNode implements CompoundDeclaration {
   @override
   String name;
 
+  @override
+  List<AvailabilityInfo> availability;
+
   @override
   covariant List<PropertyDeclaration> properties;
 
@@ -42,6 +46,7 @@ class ProtocolDeclaration extends AstNode implements CompoundDeclaration {
   ProtocolDeclaration({
     required this.id,
     required this.name,
+    required this.availability,
     required this.properties,
     required this.methods,
     required this.initializers,

pkgs/swift2objc/lib/src/ast/declarations/compounds/struct_declaration.dart

@@ -2,6 +2,7 @@
 // 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 '../../_core/interfaces/availability.dart';
 import '../../_core/interfaces/compound_declaration.dart';
 import '../../_core/interfaces/nestable_declaration.dart';
 import '../../_core/shared/referred_type.dart';
@@ -19,6 +20,9 @@ class StructDeclaration extends AstNode implements CompoundDeclaration {
   @override
   String name;
 
+  @override
+  List<AvailabilityInfo> availability;
+
   @override
   covariant List<PropertyDeclaration> properties;
 
@@ -43,6 +47,7 @@ class StructDeclaration extends AstNode implements CompoundDeclaration {
   StructDeclaration({
     required this.id,
     required this.name,
+    required this.availability,
     this.properties = const [],
     this.methods = const [],
     this.initializers = const [],

pkgs/swift2objc/lib/src/ast/declarations/enums/associated_value_enum_declaration.dart

@@ -2,6 +2,7 @@
 // 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 '../../_core/interfaces/availability.dart';
 import '../../_core/interfaces/enum_declaration.dart';
 import '../../_core/interfaces/nestable_declaration.dart';
 import '../../_core/interfaces/parameterizable.dart';
@@ -19,6 +20,9 @@ class AssociatedValueEnumDeclaration extends AstNode
   @override
   String name;
 
+  @override
+  List<AvailabilityInfo> availability;
+
   @override
   covariant List<AssociatedValueEnumCase> cases;
 
@@ -37,6 +41,7 @@ class AssociatedValueEnumDeclaration extends AstNode
   AssociatedValueEnumDeclaration({
     required this.id,
     required this.name,
+    required this.availability,
     required this.cases,
     required this.typeParams,
     required this.conformedProtocols,
@@ -68,12 +73,16 @@ class AssociatedValueEnumCase extends AstNode
   @override
   String name;
 
+  @override
+  List<AvailabilityInfo> availability;
+
   @override
   covariant List<AssociatedValueParam> params;
 
   AssociatedValueEnumCase({
     required this.id,
     required this.name,
+    required this.availability,
     required this.params,
   });