[cxx-interop] Add fix for corner case where NS_OPTIONS typedef has to be desugared

This patch is an add-on to #64043.
Essentially when encountering NS_OPTIONS enums, in C++-Interop mode
if they are not specially handled then they can mangle differently than
they do without C++-Interop. This patch adds logic to handle when a
typedef and enum have additional clang::ElaboratedType sugar, but
otherwise it does the same as the existing 64043 patch.

The test case provided was encountered in a real app build. The problem
came from when two modules are each compiled one with and one without
C++-Interop. For the test case code provided the mangling of the
protocol conformance is not consistent and the code in
SILGenLazyConformance.cpp crashes on an invalid conformance with reason
"Invalid conformance in type-checked AST".

Author: plotfi

lib/ClangImporter/ClangImporter.cpp

@@ -6877,6 +6877,22 @@ const clang::TypedefType *ClangImporter::getTypeDefForCXXCFOptionsDefinition(
   if (!enumDecl->getDeclName().isEmpty())
     return nullptr;
 
+  if (const clang::ElaboratedType *elaboratedType =
+          dyn_cast<clang::ElaboratedType>(
+              enumDecl->getIntegerType().getTypePtr())) {
+    if (auto typedefType =
+            dyn_cast<clang::TypedefType>(elaboratedType->desugar()))
+      if (auto enumExtensibilityAttr =
+              enumDecl->getAttr<clang::EnumExtensibilityAttr>();
+          enumExtensibilityAttr &&
+          enumExtensibilityAttr->getExtensibility() ==
+              clang::EnumExtensibilityAttr::Open &&
+          enumDecl->hasAttr<clang::FlagEnumAttr>()) {
+        return Impl.isUnavailableInSwift(typedefType->getDecl()) ? typedefType
+                                                                 : nullptr;
+      }
+  }
+
   if (auto typedefType = dyn_cast<clang::TypedefType>(
           enumDecl->getIntegerType().getTypePtr())) {
     if (auto enumExtensibilityAttr =

test/Interop/Cxx/objc-correctness/Inputs/NSOptionsMangling.apinotes

@@ -0,0 +1,5 @@
+---
+Name: NSOptionsMangling
+Tags:
+- Name: UIControlState
+  SwiftName: UIControl.State

test/Interop/Cxx/objc-correctness/Inputs/NSOptionsMangling.h

@@ -0,0 +1,50 @@
+#define __CF_OPTIONS_ATTRIBUTES __attribute__((flag_enum,enum_extensibility(open)))
+#if (__cplusplus)
+#define CF_OPTIONS(_type, _name) __attribute__((availability(swift,unavailable))) _type _name; enum __CF_OPTIONS_ATTRIBUTES : _name
+#else
+#define CF_OPTIONS(_type, _name) enum __CF_OPTIONS_ATTRIBUTES _name : _type _name; enum _name : _type
+#endif
+
+
+#define NS_OPTIONS(_type, _name) CF_OPTIONS(_type, _name)
+typedef unsigned long NSUInteger;
+typedef NS_OPTIONS(NSUInteger, UIControlState) {
+    UIControlStateNormal       = 0,
+    UIControlStateHighlighted  = 1 << 0,                  // used when UIControl isHighlighted is set
+};
+
+#define NS_SWIFT_UI_ACTOR __attribute__((swift_attr("@UIActor")))
+#define __API_AVAILABLE_PLATFORM_macos(x) macos,introduced=x
+#define __API_AVAILABLE_PLATFORM_macosx(x) macosx,introduced=x
+#define __API_AVAILABLE_PLATFORM_ios(x) ios,introduced=x
+#define __API_AVAILABLE_PLATFORM_watchos(x) watchos,introduced=x
+#define __API_AVAILABLE_PLATFORM_tvos(x) tvos,introduced=x
+#define __API_AVAILABLE_PLATFORM_macCatalyst(x) macCatalyst,introduced=x
+#define __API_AVAILABLE_PLATFORM_macCatalyst(x) macCatalyst,introduced=x
+#define __API_AVAILABLE_PLATFORM_uikitformac(x) uikitformac,introduced=x
+#define __API_AVAILABLE_PLATFORM_driverkit(x) driverkit,introduced=x
+#define __API_A(x) __attribute__((availability(__API_AVAILABLE_PLATFORM_##x)))
+#define __API_AVAILABLE1(x) __API_A(x)
+#define __API_AVAILABLE2(x,y) __API_A(x) __API_A(y)
+#define __API_AVAILABLE3(x,y,z)  __API_A(x) __API_A(y) __API_A(z)
+#define __API_AVAILABLE4(x,y,z,t) __API_A(x) __API_A(y) __API_A(z) __API_A(t)
+#define __API_AVAILABLE5(x,y,z,t,b) __API_A(x) __API_A(y) __API_A(z) __API_A(t) __API_A(b)
+#define __API_AVAILABLE6(x,y,z,t,b,m) __API_A(x) __API_A(y) __API_A(z) __API_A(t) __API_A(b) __API_A(m)
+#define __API_AVAILABLE7(x,y,z,t,b,m,d) __API_A(x) __API_A(y) __API_A(z) __API_A(t) __API_A(b) __API_A(m) __API_A(d)
+#define __API_AVAILABLE8(x,y,z,t,b,m,d,l) __API_A(x) __API_A(y) __API_A(z) __API_A(t) __API_A(b) __API_A(m) __API_A(d) __API_A(l)
+#define __API_AVAILABLE_GET_MACRO(_1,_2,_3,_4,_5,_6,_7,_8,NAME,...) NAME
+#define API_AVAILABLE(...) __API_AVAILABLE_GET_MACRO(__VA_ARGS__,__API_AVAILABLE8, __API_AVAILABLE7, __API_AVAILABLE6, __API_AVAILABLE5, __API_AVAILABLE4, __API_AVAILABLE3, __API_AVAILABLE2, __API_AVAILABLE1, 0)(__VA_ARGS__)
+
+#ifdef __cplusplus
+#define UIKIT_EXTERN		extern "C" __attribute__((visibility ("default")))
+#else
+#define UIKIT_EXTERN	        extern __attribute__((visibility ("default")))
+#endif
+
+@interface UIView
+@end
+
+UIKIT_EXTERN API_AVAILABLE(ios(2.0)) NS_SWIFT_UI_ACTOR
+@interface UIControl : UIView
+@end
+

test/Interop/Cxx/objc-correctness/Inputs/module.modulemap

@@ -9,3 +9,6 @@ module CxxClassWithNSStringInit [extern_c] {
   requires cplusplus
 }
 
+module NSOptionsMangling {
+  header "NSOptionsMangling.h"
+}

test/Interop/Cxx/objc-correctness/ns-options-mangling.swift

@@ -0,0 +1,8 @@
+// RUN: %target-swift-frontend -I %S/Inputs -c -cxx-interoperability-mode=swift-5.9 %s -S -o - | %FileCheck %s
+
+// CHECK: _$sSo14UIControlStateV4main7FooableACMc
+// The following check is to ensure the conformance is mangled properly:
+// protocol conformance descriptor for __C.UIControlState : main.Fooable in main
+import NSOptionsMangling
+protocol Fooable { }
+extension UIControl.State: Fooable {}