[swift2objc] Stub transitive deps

pkgs/ffigen/lib/src/header_parser/parser.dart

@@ -175,39 +175,33 @@ List<Binding> transformBindings(List<Binding> bindings, Context context) {
     applyConfigFiltersVisitation.indirectlyIncluded,
   );
 
-  final findByValueCompoundsVisitation = FindByValueCompoundsVisitation();
-  visit(
+  final byValueCompounds = visit(
     context,
-    findByValueCompoundsVisitation,
+    FindByValueCompoundsVisitation(),
     FindByValueCompoundsVisitation.rootNodes(included),
-  );
-  final byValueCompounds = findByValueCompoundsVisitation.byValueCompounds;
+  ).byValueCompounds;
   visit(
     context,
     ClearOpaqueCompoundMembersVisitation(config, byValueCompounds, included),
     bindings,
   );
 
-  final findTransitiveDepsVisitation = FindTransitiveDepsVisitation();
-  visit(context, findTransitiveDepsVisitation, included);
-  final transitives = findTransitiveDepsVisitation.transitives;
-  final findDirectTransitiveDepsVisitation = FindDirectTransitiveDepsVisitation(
-    config,
+  final transitives = visit(
+    context,
+    FindTransitiveDepsVisitation(),
     included,
-    directlyIncluded,
-  );
-  visit(context, findDirectTransitiveDepsVisitation, included);
-  final directTransitives =
-      findDirectTransitiveDepsVisitation.directTransitives;
-
-  final listBindingsVisitation = ListBindingsVisitation(
-    config,
+  ).transitives;
+  final directTransitives = visit(
+    context,
+    FindDirectTransitiveDepsVisitation(config, included, directlyIncluded),
     included,
-    transitives,
-    directTransitives,
-  );
-  visit(context, listBindingsVisitation, bindings);
-  final finalBindings = listBindingsVisitation.bindings;
+  ).directTransitives;
+
+  final finalBindings = visit(
+    context,
+    ListBindingsVisitation(config, included, transitives, directTransitives),
+    bindings,
+  ).bindings;
   visit(context, MarkBindingsVisitation(finalBindings), bindings);
 
   final finalBindingsList = finalBindings.toList();

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

@@ -49,6 +49,9 @@ class ClassDeclaration extends AstNode
   /// If this class is a wrapper for another entity (class, struct, etc)
   bool isWrapper;
 
+  // Whether this is a stub wrapper.
+  bool isStub;
+
   /// An instance of the original entity that this class is wraping
   PropertyDeclaration? wrappedInstance;
 
@@ -77,6 +80,7 @@ class ClassDeclaration extends AstNode
     this.hasObjCAnnotation = false,
     this.superClass,
     this.isWrapper = false,
+    this.isStub = false,
     this.wrappedInstance,
     this.wrapperInitializer,
     this.initializers = const [],

pkgs/swift2objc/lib/src/ast/declarations/globals/globals.dart

@@ -62,6 +62,10 @@ class GlobalFunctionDeclaration extends AstNode implements FunctionDeclaration {
     this.async = false,
   });
 
+  @override
+  void visit(Visitation visitation) =>
+      visitation.visitGlobalFunctionDeclaration(this);
+
   @override
   void visitChildren(Visitor visitor) {
     super.visitChildren(visitor);
@@ -104,6 +108,10 @@ class GlobalVariableDeclaration extends AstNode implements VariableDeclaration {
     required this.async,
   }) : assert(!(throws && !isConstant));
 
+  @override
+  void visit(Visitation visitation) =>
+      visitation.visitGlobalVariableDeclaration(this);
+
   @override
   void visitChildren(Visitor visitor) {
     super.visitChildren(visitor);

pkgs/swift2objc/lib/src/generator/generators/class_generator.dart

@@ -13,6 +13,7 @@ import '../generator.dart';
 
 List<String> generateClass(ClassDeclaration declaration) {
   return [
+    if (declaration.isStub) ..._generateStubComment(declaration),
     ...generateAvailability(declaration),
     '${_generateClassHeader(declaration)} {',
     ...[
@@ -26,6 +27,14 @@ List<String> generateClass(ClassDeclaration declaration) {
   ];
 }
 
+List<String> _generateStubComment(ClassDeclaration declaration) {
+  final wrappedType = declaration.wrappedInstance!.type.swiftType;
+  return [
+    '// This wrapper is a stub. To generate the full wrapper, add $wrappedType',
+    "// to your config's include function.",
+  ];
+}
+
 String _generateClassHeader(ClassDeclaration declaration) {
   final header = StringBuffer();
 

pkgs/swift2objc/lib/src/transformer/_core/dependencies.dart

@@ -4,29 +4,104 @@
 
 import '../../ast/_core/interfaces/compound_declaration.dart';
 import '../../ast/_core/interfaces/declaration.dart';
+import '../../ast/declarations/compounds/class_declaration.dart';
+import '../../ast/declarations/compounds/protocol_declaration.dart';
+import '../../ast/declarations/compounds/struct_declaration.dart';
 import '../../ast/declarations/globals/globals.dart';
 import '../../ast/visitor.dart';
 
-class DependencyVisitation extends Visitation {
-  Set<Declaration> topLevelDeclarations = {};
+class FindIncludesVisitation extends Visitation {
+  final bool Function(Declaration) filter;
+  final includes = <Declaration>{};
+
+  FindIncludesVisitation(this.filter);
+
+  @override
+  void visitDeclaration(Declaration node) {
+    if (filter(node)) {
+      includes.add(node);
+      node.visitChildren(visitor);
+    }
+  }
+}
+
+class ListDeclsVisitation extends Visitation {
+  final Set<Declaration> includes;
+  final Set<Declaration> directTransitives;
+  final topLevelDecls = <Declaration>{};
+  final stubDecls = <Declaration>{};
+
+  ListDeclsVisitation(this.includes, this.directTransitives);
 
   @override
   void visitGlobalFunctionDeclaration(GlobalFunctionDeclaration node) {
     node.visitChildren(visitor);
-    topLevelDeclarations.add(node);
+    topLevelDecls.add(node);
   }
 
   @override
   void visitGlobalVariableDeclaration(GlobalVariableDeclaration node) {
     node.visitChildren(visitor);
-    topLevelDeclarations.add(node);
+    topLevelDecls.add(node);
   }
 
   @override
   void visitCompoundDeclaration(CompoundDeclaration node) {
     node.visitChildren(visitor);
 
     // Don't add nested classes etc to the top level declarations.
-    if (node.nestingParent == null) topLevelDeclarations.add(node);
+    if (node.nestingParent == null) topLevelDecls.add(node);
+
+    if (!includes.contains(node) && directTransitives.contains(node)) {
+      stubDecls.add(node);
+    }
+  }
+}
+
+class FindDirectTransitiveDepsVisitation extends Visitation {
+  final Set<Declaration> includes;
+  final directTransitives = <Declaration>{};
+
+  FindDirectTransitiveDepsVisitation(this.includes);
+
+  void _visitImpl(Declaration node, bool forceVisitChildren) {
+    directTransitives.add(node);
+    if (forceVisitChildren || includes.contains(node)) {
+      node.visitChildren(visitor);
+    }
+  }
+
+  @override
+  void visitDeclaration(Declaration node) => _visitImpl(node, true);
+
+  @override
+  void visitClassDeclaration(ClassDeclaration node) {
+    _visitImpl(node, false);
+
+    // Always visit the super type, protocols, and nesting parent, regardless of
+    // whether the node is directly included. This ensures that super types etc
+    // of stubs are also stubs, rather than being omitted like the rest of the
+    // stub's children.
+    visitor.visit(node.superClass);
+    visitor.visitAll(node.conformedProtocols);
+    visitor.visit(node.nestingParent);
+  }
+
+  @override
+  void visitProtocolDeclaration(ProtocolDeclaration node) {
+    _visitImpl(node, false);
+
+    // See visitClassDeclaration.
+    visitor.visitAll(node.conformedProtocols);
+    visitor.visit(node.nestingParent);
+  }
+
+  @override
+  void visitStructDeclaration(StructDeclaration node) {
+    _visitImpl(node, false);
+
+    // See visitClassDeclaration.
+    visitor.visitAll(node.conformedProtocols);
+    visitor.visit(node.nestingParent);
   }
 }

pkgs/swift2objc/lib/src/transformer/_core/primitive_wrappers.dart

@@ -46,7 +46,7 @@ ReferredType _createWrapperClass(DeclaredType primitiveType) {
 (ReferredType, bool) maybeGetPrimitiveWrapper(
   ReferredType type,
   bool shouldWrapPrimitives,
-  TransformationMap transformationMap,
+  TransformationState state,
 ) {
   if (type is! DeclaredType || !shouldWrapPrimitives) {
     return (type, false);
@@ -57,7 +57,7 @@ ReferredType _createWrapperClass(DeclaredType primitiveType) {
     return (type, false);
   }
 
-  transformationMap[type.declaration] = (wrapper as DeclaredType).declaration;
+  state.map[type.declaration] = (wrapper as DeclaredType).declaration;
   return (wrapper, true);
 }
 

pkgs/swift2objc/lib/src/transformer/_core/utils.dart

@@ -18,10 +18,10 @@ import 'unique_namer.dart';
 // that weird. Refactor this as part of the transformer refactor.
 
 (String value, ReferredType type) maybeWrapValue(ReferredType type,
-    String value, UniqueNamer globalNamer, TransformationMap transformationMap,
+    String value, UniqueNamer globalNamer, TransformationState state,
     {bool shouldWrapPrimitives = false}) {
   final (wrappedPrimitiveType, returnsWrappedPrimitive) =
-      maybeGetPrimitiveWrapper(type, shouldWrapPrimitives, transformationMap);
+      maybeGetPrimitiveWrapper(type, shouldWrapPrimitives, state);
   if (returnsWrappedPrimitive) {
     return (
       '${(wrappedPrimitiveType as DeclaredType).name}($value)',
@@ -38,15 +38,14 @@ import 'unique_namer.dart';
   } else if (type is DeclaredType) {
     final declaration = type.declaration;
     if (declaration is TypealiasDeclaration) {
-      return maybeWrapValue(
-          declaration.target, value, globalNamer, transformationMap,
+      return maybeWrapValue(declaration.target, value, globalNamer, state,
           shouldWrapPrimitives: shouldWrapPrimitives);
     }
 
     final transformedTypeDeclaration = transformDeclaration(
       declaration,
       globalNamer,
-      transformationMap,
+      state,
     );
 
     return (
@@ -55,7 +54,7 @@ import 'unique_namer.dart';
     );
   } else if (type is OptionalType) {
     final (newValue, newType) =
-        maybeWrapValue(type.child, '$value!', globalNamer, transformationMap);
+        maybeWrapValue(type.child, '$value!', globalNamer, state);
     return (
       '$value == nil ? nil : $newValue',
       OptionalType(newType),