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

Normally, we diagnose @NSManaged properties that have getters and
setters because they are actually supposed to be stored properties with
special synthesized accessors. Since we print those accessors in module
interfaces, just don't error when we see them.

Fixes rdar://56111556

Author: Harlan Haskins

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: }
+}