Address review comments

Author: kovdan01

SwiftCompilerSources/Sources/AST/DeclContext.swift

@@ -1,3 +1,15 @@
+//===--- DeclContext.swift -----------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2025 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
 import ASTBridging
 
 public protocol DeclContext : AnyObject {
@@ -8,6 +20,8 @@ extension DeclContext {
   public var astContext: ASTContext { bridgedDeclContext.astContext }
 }
 
+// Used for DeclContext classes which are not Decls and are not bridged, yet. E.g. `FileUnit`.
+// TODO: once we have bridged those DeclContext classes, get rid of UnknownDeclContext
 public class UnknownDeclContext : DeclContext {
   public var bridgedDeclContext: BridgedDeclContext
   public init(bridged: BridgedDeclContext) { bridgedDeclContext = bridged }

SwiftCompilerSources/Sources/AST/Declarations.swift

@@ -2,7 +2,7 @@
 //
 // This source file is part of the Swift.org open source project
 //
-// Copyright (c) 2014 - 2024 Apple Inc. and the Swift project authors
+// Copyright (c) 2014 - 2025 Apple Inc. and the Swift project authors
 // Licensed under Apache License v2.0 with Runtime Library Exception
 //
 // See https://swift.org/LICENSE.txt for license information
@@ -23,19 +23,22 @@ public class Decl: CustomStringConvertible, Hashable {
   /// The module in which this declaration resides.
   final public var parentModule: ModuleDecl { bridged.getModuleContext().getAs(ModuleDecl.self) }
 
-  /// The parent DeclContext if it is a Decl.
-  final public var parent: Decl? { bridged.getParent().decl }
-
-  // True if this declaration is imported from C/C++/ObjC.
-  final public var hasClangNode: Bool { bridged.hasClangNode() }
-
-  final public var declContext: DeclContext {
-    if let decl = parent {
+  /// The parent DeclContext.
+  final public var parentDeclContext: DeclContext? {
+    if let decl = bridged.getParent().decl {
       return decl as! DeclContext
     }
-    return UnknownDeclContext(bridged: bridged.getDeclContext())
+    if let bridgedDeclContext = BridgedDeclContext(bridged: bridged.getDeclContext()) {
+      // A DeclContext which is not a Decl.
+      // TODO: once we have bridged those DeclContext classes, get rid of UnknownDeclContext
+      return UnknownDeclContext(bridged: bridgedDeclContext)
+    }
+    return nil
   }
 
+  // True if this declaration is imported from C/C++/ObjC.
+  final public var hasClangNode: Bool { bridged.hasClangNode() }
+
   final public var bridgedDecl: BridgedDecl { BridgedDecl(raw: bridged.obj) }
 
   public static func ==(lhs: Decl, rhs: Decl) -> Bool { lhs === rhs }
@@ -153,7 +156,9 @@ final public class GenericTypeParamDecl: TypeDecl {
 
 final public class AssociatedTypeDecl: TypeDecl {}
 
-final public class ModuleDecl: TypeDecl {}
+final public class ModuleDecl: TypeDecl, DeclContext {
+  public var bridgedDeclContext: BridgedDeclContext { bridged.asModuleDecl() }
+}
 
 public class AbstractStorageDecl: ValueDecl {
   final public var isConst: Bool { bridged.AbstractStorage_isConst() }
@@ -171,9 +176,9 @@ final public class ParamDecl: VarDecl {
   }
 }
 
-final public class SubscriptDecl: AbstractStorageDecl {}
+final public class SubscriptDecl: AbstractStorageDecl, GenericContext {}
 
-public class AbstractFunctionDecl: ValueDecl {
+public class AbstractFunctionDecl: ValueDecl, GenericContext {
   public var isOverridden: Bool { bridged.AbstractFunction_isOverridden() }
 }
 
@@ -209,9 +214,11 @@ final public class EnumElementDecl: ValueDecl {
   }
 }
 
-final public class ExtensionDecl: Decl {}
+final public class ExtensionDecl: Decl, GenericContext {}
 
-final public class TopLevelCodeDecl: Decl {}
+final public class TopLevelCodeDecl: Decl, DeclContext {
+  public var bridgedDeclContext: BridgedDeclContext { bridged.asTopLevelCodeDecl() }
+}
 
 final public class ImportDecl: Decl {}
 
@@ -320,9 +327,17 @@ extension GenericParameterList {
 
 extension BridgedDecl {
   public var declObj: BridgedDeclObj {
-    BridgedDeclObj(SwiftObject(raw.bindMemory(to: BridgedSwiftObject.self, capacity: 1)))
+    BridgedDeclObj(self)
+  }
+}
+
+extension BridgedDeclContext {
+  public init?(bridged: BridgedNullableDeclContext) {
+    guard let raw = bridged.raw else {
+      return nil
+    }
+    self.init(raw: raw)
   }
-  public var decl: Decl { declObj.decl }
 }
 
 extension SourceFile {

SwiftCompilerSources/Sources/Optimizer/ModulePasses/EmbeddedSwiftDiagnostics.swift

@@ -347,7 +347,7 @@ private extension Function {
         if decl is DestructorDecl || decl is ConstructorDecl {
           return 4
         }
-        if let parent = decl.parent, parent is ClassDecl {
+        if let parent = decl.parentDeclContext, parent is ClassDecl {
           return 2
         }
       }

include/swift/AST/ASTBridging.h

@@ -318,12 +318,15 @@ struct BridgedDeclObj {
 #endif
 
   BridgedDeclObj(SwiftObject obj) : obj(obj) {}
+  BridgedDeclObj(BridgedDecl decl) : obj(decl.unbridged()) {}
   BridgedOwnedString getDebugDescription() const;
   BRIDGED_INLINE swift::SourceLoc getLoc() const;
   SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedDeclObj getModuleContext() const;
   SWIFT_IMPORT_UNSAFE BRIDGED_INLINE OptionalBridgedDeclObj getParent() const;
-  SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedDeclContext getDeclContext() const;
+  SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedNullableDeclContext getDeclContext() const;
   SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedDeclContext asGenericContext() const;
+  SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedDeclContext asTopLevelCodeDecl() const;
+  SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedDeclContext asModuleDecl() const;
   BRIDGED_INLINE void setImplicit() const;
   SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedStringRef Type_getName() const;
   SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedStringRef Value_getUserFacingName() const;

include/swift/AST/ASTBridgingImpl.h

@@ -177,14 +177,22 @@ OptionalBridgedDeclObj BridgedDeclObj::getParent() const {
   return {unbridged()->getDeclContext()->getAsDecl()};
 }
 
-BridgedDeclContext BridgedDeclObj::getDeclContext() const {
+BridgedNullableDeclContext BridgedDeclObj::getDeclContext() const {
   return {unbridged()->getDeclContext()};
 }
 
 BridgedDeclContext BridgedDeclObj::asGenericContext() const {
   return {static_cast<swift::DeclContext *>(getAs<swift::GenericContext>())};
 }
 
+BridgedDeclContext BridgedDeclObj::asTopLevelCodeDecl() const {
+  return {static_cast<swift::DeclContext *>(getAs<swift::TopLevelCodeDecl>())};
+}
+
+BridgedDeclContext BridgedDeclObj::asModuleDecl() const {
+  return {static_cast<swift::DeclContext *>(getAs<swift::ModuleDecl>())};
+}
+
 void BridgedDeclObj::setImplicit() const {
   unbridged()->setImplicit();
 }

include/swift/AST/ASTBridgingWrappers.def

@@ -94,7 +94,7 @@
 // Some of the base classes need to be nullable to allow them to be used as
 // optional parameters.
 AST_BRIDGING_WRAPPER_NULLABLE(Decl)
-AST_BRIDGING_WRAPPER_NONNULL(DeclContext)
+AST_BRIDGING_WRAPPER_NULLABLE(DeclContext)
 AST_BRIDGING_WRAPPER_NONNULL(GenericContext)
 AST_BRIDGING_WRAPPER_NONNULL(FileUnit)
 AST_BRIDGING_WRAPPER_NULLABLE(SourceFile)