Merge pull request swiftlang#32529 from nkcsgexi/64538537

AST: isEquivalentToExtendedContext() should consider use patterns of @_originallyDefinedIn

Author: nkcsgexi

lib/AST/Decl.cpp

@@ -1297,7 +1297,12 @@ bool ExtensionDecl::isConstrainedExtension() const {
 
 bool ExtensionDecl::isEquivalentToExtendedContext() const {
   auto decl = getExtendedNominal();
-  return getParentModule() == decl->getParentModule()
+  auto extendDeclfromSameModule =
+    getParentModule() == decl->getParentModule() ||
+    // if the extended type was defined in the same module with the extension,
+    // we should consider them as the same module to preserve ABI stability.
+    decl->getAlternateModuleName() == getParentModule()->getNameStr();
+  return extendDeclfromSameModule
     && !isConstrainedExtension()
     && !getDeclaredInterfaceType()->isExistentialType();
 }

test/TBD/move_to_extension.swift

@@ -0,0 +1,54 @@
+// REQUIRES: OS=macosx
+// RUN: %empty-directory(%t)
+
+// RUN: %target-swift-frontend -typecheck %s -emit-tbd -emit-tbd-path %t/before_move.tbd -D BEFORE_MOVE -module-name Foo -enable-library-evolution
+// RUN: %FileCheck %s < %t/before_move.tbd
+
+// RUN: %target-swift-frontend %s -emit-module -emit-module-path %t/FooCore.swiftmodule -D AFTER_MOVE_FOO_CORE -module-name FooCore -enable-library-evolution
+// RUN: %target-swift-frontend -typecheck %s -emit-tbd -emit-tbd-path %t/after_move.tbd -D AFTER_MOVE_FOO -module-name Foo -I %t -enable-library-evolution
+// RUN: %FileCheck %s < %t/after_move.tbd
+
+// CHECK: '_$s3Foo4DateC14getCurrentYearSiyFZ'
+// CHECK: '_$s3Foo9DateValueV4yearACSi_tcfC'
+// CHECK: '_$s3Foo9DateValueV4yearSivg'
+// CHECK: '_$s3Foo9DateValueV4yearSivpMV'
+
+#if BEFORE_MOVE
+
+public class Date {
+  public static func getCurrentYear() -> Int { return 2020 }
+}
+
+public struct DateValue {
+  public init(year: Int) {}
+  public var year: Int { return 2020 }
+}
+
+#endif
+
+#if AFTER_MOVE_FOO_CORE
+
+@available(OSX 10.7, *)
+@_originallyDefinedIn(module: "Foo", OSX 10.9)
+public class Date {}
+
+@available(OSX 10.7, *)
+@_originallyDefinedIn(module: "Foo", OSX 10.9)
+public struct DateValue {}
+
+#endif
+
+#if AFTER_MOVE_FOO
+
+@_exported import FooCore
+
+public extension Date {
+  public static func getCurrentYear() -> Int { return 2020 }
+}
+
+public extension DateValue {
+  public init(year: Int) {}
+  public var year: Int { return 2020 }
+}
+
+#endif