[cxx-interop] fix the use of '.pointee' with getter accessor for derived-to-base synthesized accessor

Author: hyp

lib/ClangImporter/ClangImporter.cpp

@@ -5450,8 +5450,10 @@ makeBaseClassMemberAccessors(DeclContext *declContext,
   auto computedType = computedVar->getInterfaceType();
 
   // Use 'address' or 'mutableAddress' accessors for non-copyable
-  // types.
-  bool useAddress = computedType->isNoncopyable(declContext);
+  // types, unless the base accessor returns it by value.
+  bool useAddress = computedType->isNoncopyable(declContext) &&
+                    (baseClassVar->getReadImpl() == ReadImplKind::Stored ||
+                     baseClassVar->getAccessor(AccessorKind::Address));
 
   ParameterList *bodyParams = nullptr;
   if (auto subscript = dyn_cast<SubscriptDecl>(baseClassVar)) {

test/Interop/Cxx/operators/move-only/Inputs/move-only-cxx-value-operators.h

@@ -74,4 +74,6 @@ using NonCopyableHolderMutDerefDerivedDerived = OneDerived<OneDerived<NonCopyabl
 
 using NonCopyableHolderValueConstDerefDerivedDerived = OneDerived<OneDerived<NonCopyableHolderValueConstDeref>>;
 
+using NonCopyableHolderValueMutDerefDerivedDerived = OneDerived<OneDerived<NonCopyableHolderValueMutDeref>>;
+
 #endif // TEST_INTEROP_CXX_OPERATORS_MOVE_ONLY_OPS_H

test/Interop/Cxx/operators/move-only/move-only-synthesized-properties.swift

@@ -129,4 +129,20 @@ MoveOnlyCxxOperators.test("testNonCopyableHolderMutDerefDerivedDerived pointee b
   expectEqual(holder.pointee.x, 0)
 }
 
+MoveOnlyCxxOperators.test("testNonCopyableHolderValueConstDerefDerivedDerived pointee value") {
+  let holder = NonCopyableHolderValueConstDerefDerivedDerived(11)
+  var k = holder.pointee
+  expectEqual(k.x, 11)
+  var k2 = holder.pointee
+  expectEqual(k.x, k2.x)
+}
+
+MoveOnlyCxxOperators.test("testNonCopyableHolderValueMutDerefDerivedDerived pointee value") {
+  let holder = NonCopyableHolderValueMutDerefDerivedDerived(23)
+  var k = holder.pointee
+  expectEqual(k.x, 23)
+  var k2 = holder.pointee
+  expectEqual(k.x, k2.x)
+}
+
 runAllTests()