From 764bf831456c5f158651a5a6626b51fa62ebe28f Mon Sep 17 00:00:00 2001
From: Jordan Rose <jordan_rose@apple.com>
Date: Thu, 6 Oct 2016 09:44:12 -0700
Subject: [PATCH] SR-2673: @NSManaged property can't satisfy protocol
 requirement (#5141)

Targeted fix for SR-2673: if a potential protocol witness is
@NSManaged, add accessors the NSManaged way, not the stored property
way.

There's probably more weirdness around here, so I'll clone the bug to
go through maybeAddAccessorsToVariable a lot more often. (Lazy
properties could easily be broken in the same way.)
---
 lib/Sema/CodeSynthesis.cpp            |  5 ++++-
 test/SILGen/objc_attr_NSManaged.swift | 17 +++++++++++++++++
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/lib/Sema/CodeSynthesis.cpp b/lib/Sema/CodeSynthesis.cpp
index 5ab84b15f57..1d4a7527fda 100644
--- a/lib/Sema/CodeSynthesis.cpp
+++ b/lib/Sema/CodeSynthesis.cpp
@@ -820,7 +820,10 @@ void TypeChecker::synthesizeAccessorsForStorage(AbstractStorageDecl *storage,
   // If the decl is stored, convert it to StoredWithTrivialAccessors
   // by synthesizing the full set of accessors.
   if (!storage->hasAccessorFunctions()) {
-    addTrivialAccessorsToStorage(storage, *this);
+    if (storage->getAttrs().hasAttribute<NSManagedAttr>())
+      maybeAddAccessorsToVariable(cast<VarDecl>(storage), *this);
+    else
+      addTrivialAccessorsToStorage(storage, *this);
     return;
   }
 
diff --git a/test/SILGen/objc_attr_NSManaged.swift b/test/SILGen/objc_attr_NSManaged.swift
index 13193f1daff..25cf49c8753 100644
--- a/test/SILGen/objc_attr_NSManaged.swift
+++ b/test/SILGen/objc_attr_NSManaged.swift
@@ -78,6 +78,19 @@ func testFinal(_ obj: FinalGizmo) -> String {
   return obj.y
 }
 
+// SR-2673: @NSManaged property can't satisfy protocol requirement
+@objc protocol ObjCProto {
+  var managedProp: String { get set }
+  var managedExtProp: AnyObject { get }
+}
+
+class ProtoAdopter: Gizmo, ObjCProto {
+  @NSManaged var managedProp: String
+}
+extension ProtoAdopter {
+  @NSManaged var managedExtProp: AnyObject
+}
+
 
 // CHECK-NOT: sil hidden @_TToFC19objc_attr_NSManaged10SwiftGizmog1xCS_1X : $@convention(objc_method) (SwiftGizmo) -> @autoreleased X
 // CHECK-NOT: sil hidden @_TToFC19objc_attr_NSManaged10SwiftGizmos1xCS_1X
@@ -100,3 +113,7 @@ func testFinal(_ obj: FinalGizmo) -> String {
 // CHECK-NEXT:   #SwiftGizmo.init!initializer.1: _TFC19objc_attr_NSManaged10FinalGizmoc
 // CHECK-NEXT:   #FinalGizmo.deinit!deallocator: _TFC19objc_attr_NSManaged10FinalGizmoD
 // CHECK-NEXT: }
+
+// CHECK-LABEL: sil_vtable ProtoAdopter {
+// CHECK-NOT: managed{{.*}}Prop
+// CHECK: {{^}$}}