Swift AST: add some Decl APIs

* in `Decl`: `var parent: Decl?`
* in `ProtocolDecl`: `var requiresClass: Bool`

Author: eeckstein

SwiftCompilerSources/Sources/AST/Declarations.swift

@@ -23,6 +23,9 @@ public class Decl: CustomStringConvertible, Hashable {
   /// The module in which this declaration resides.
   public var parentModule: ModuleDecl { bridged.getModuleContext().getAs(ModuleDecl.self) }
 
+  /// The parent DeclContext if it is a Decl.
+  public var parent: Decl? { bridged.getParent().decl }
+
   // True if this declaration is imported from C/C++/ObjC.
   public var hasClangNode: Bool { bridged.hasClangNode() }
 
@@ -69,7 +72,9 @@ final public class ClassDecl: NominalTypeDecl {
   }
 }
 
-final public class ProtocolDecl: NominalTypeDecl {}
+final public class ProtocolDecl: NominalTypeDecl {
+  public var requiresClass: Bool { bridged.ProtocolDecl_requiresClass() }
+}
 
 final public class BuiltinTupleDecl: NominalTypeDecl {}
 

include/swift/AST/ASTBridging.h

@@ -379,6 +379,7 @@ struct BridgedDeclObj {
   BridgedOwnedString getDebugDescription() const;
   BRIDGED_INLINE BridgedSourceLoc getLoc() const;
   SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedDeclObj getModuleContext() const;
+  SWIFT_IMPORT_UNSAFE BRIDGED_INLINE OptionalBridgedDeclObj getParent() const;
   SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedStringRef Type_getName() const;
   SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedStringRef Value_getUserFacingName() const;
   SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedSourceLoc Value_getNameLoc() const;
@@ -391,6 +392,7 @@ struct BridgedDeclObj {
   BRIDGED_INLINE bool Struct_hasUnreferenceableStorage() const;
   SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedASTType Class_getSuperclass() const;
   SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedDeclObj Class_getDestructor() const;
+  BRIDGED_INLINE bool ProtocolDecl_requiresClass() const;
   BRIDGED_INLINE bool AbstractFunction_isOverridden() const;
   BRIDGED_INLINE bool Destructor_isIsolated() const;
 };

include/swift/AST/ASTBridgingImpl.h

@@ -180,6 +180,10 @@ BridgedDeclObj BridgedDeclObj::getModuleContext() const {
   return {unbridged()->getModuleContext()};
 }
 
+OptionalBridgedDeclObj BridgedDeclObj::getParent() const {
+  return {unbridged()->getDeclContext()->getAsDecl()};
+}
+
 BridgedStringRef BridgedDeclObj::Type_getName() const {
   return getAs<swift::TypeDecl>()->getName().str();
 }
@@ -228,6 +232,10 @@ BridgedDeclObj BridgedDeclObj::Class_getDestructor() const {
   return {getAs<swift::ClassDecl>()->getDestructor()};
 }
 
+bool BridgedDeclObj::ProtocolDecl_requiresClass() const {
+  return getAs<swift::ProtocolDecl>()->requiresClass();
+}
+
 bool BridgedDeclObj::AbstractFunction_isOverridden() const {
   return getAs<swift::AbstractFunctionDecl>()->isOverridden();
 }