[ModuleInterfaces] Don't diagnose @NSManaged properties with accessors

lib/Sema/TypeCheckStorage.cpp

@@ -2538,7 +2538,16 @@ static void finishNSManagedImplInfo(VarDecl *var,
   if (var->isLet())
     diagnoseAndRemoveAttr(var, attr, diag::attr_NSManaged_let_property);
 
+  SourceFile *parentFile = var->getDeclContext()->getParentSourceFile();
+
   auto diagnoseNotStored = [&](unsigned kind) {
+    // Skip diagnosing @NSManaged declarations in module interfaces. They are
+    // properties that are stored, but have specially synthesized observers
+    // and we should allow them to have getters and setters in a module
+    // interface.
+    if (parentFile && parentFile->Kind == SourceFileKind::Interface)
+      return;
+
     diagnoseAndRemoveAttr(var, attr, diag::attr_NSManaged_not_stored, kind);
   };
 

test/ModuleInterface/nsmanaged-attr.swift

@@ -0,0 +1,41 @@
+// RUN: %empty-directory(%t)
+
+// This test ensures we can properly load modules that have @NSManaged properties.
+
+// 1. Emit this file to a module interface
+// RUN: %target-swift-frontend -typecheck -emit-module-interface-path %t/Module.swiftinterface %s -enable-library-evolution -module-name Module
+
+// 2. Check the interface against what we expect
+// RUN: %FileCheck %s < %t/Module.swiftinterface
+
+// 3. Ensure we can load this module from its interface
+// RUN: echo 'import Module' | %target-swift-frontend -typecheck - -I %t
+
+// REQUIRES: objc_interop
+
+import CoreData
+import Foundation
+
+// CHECK: @objc public class MyObject : CoreData.NSManagedObject {
+public class MyObject: NSManagedObject {
+  // CHECK: @objc @NSManaged dynamic public var myVar: Swift.String {
+  // CHECK-NEXT: @objc get
+  // CHECK-NEXT: @objc set
+  // CHECK-NEXT: }
+  @NSManaged public var myVar: String
+  // CHECK: @NSManaged @objc dynamic public var myVar2: Swift.String {
+  // CHECK-NEXT: @objc get
+  // CHECK-NEXT: @objc set
+  // CHECK-NEXT: }
+  @NSManaged @objc public var myVar2: String
+  // CHECK: @NSManaged @objc dynamic public var myVar3: Swift.String {
+  // CHECK-NEXT: @objc get
+  // CHECK-NEXT: @objc set
+  // CHECK-NEXT: }
+  @NSManaged @objc dynamic public var myVar3: String
+  // CHECK: @NSManaged @objc dynamic public var myVar4: Swift.String {
+  // CHECK-NEXT: @objc get
+  // CHECK-NEXT: }
+  @NSManaged @objc dynamic public private(set) var myVar4: String
+// CHECK: }
+}