Revert "Revert "Revert "[cxx-interop] Import custom NS_OPTIONS correctly"""

This reverts commit f7c2257.

Author: hyp

lib/ClangImporter/ImportType.cpp

@@ -2646,31 +2646,44 @@ ArgumentAttrs ClangImporter::Implementation::inferDefaultArgument(
     }
   } else if (const clang::TypedefType *typedefType =
                  type->getAs<clang::TypedefType>()) {
-    clang::TypedefNameDecl *typedefDecl = typedefType->getDecl();
-    // Find the next decl in the same context. If this typedef is a part of an
-    // NS/CF_OPTIONS declaration, the next decl will be an enum.
-    auto declsInContext = typedefDecl->getDeclContext()->decls();
-    auto declIter = llvm::find(declsInContext, typedefDecl);
-    if (declIter != declsInContext.end())
-      declIter++;
-    if (declIter != declsInContext.end()) {
-      if (auto enumDecl = dyn_cast<clang::EnumDecl>(*declIter)) {
-        if (auto cfOptionsTy =
-                nameImporter.getContext()
-                    .getClangModuleLoader()
-                    ->getTypeDefForCXXCFOptionsDefinition(enumDecl)) {
-          if (cfOptionsTy->getDecl() == typedefDecl) {
-            auto enumName = typedefDecl->getName();
-            ArgumentAttrs argumentAttrs(DefaultArgumentKind::None, true,
-                                        enumName);
-            for (auto word : llvm::reverse(camel_case::getWords(enumName))) {
-              if (camel_case::sameWordIgnoreFirstCase(word, "options")) {
-                argumentAttrs.argumentKind = DefaultArgumentKind::EmptyArray;
-              }
-            }
-            return argumentAttrs;
-          }
+    // Get the AvailabilityAttr that would be set from CF/NS_OPTIONS
+    if (importer::isUnavailableInSwift(typedefType->getDecl(), nullptr, true)) {
+      // If we've taken this branch it means we have an enum type, and it is
+      // likely an integer or NSInteger that is being used by NS/CF_OPTIONS to
+      // behave like a C enum in the presence of C++.
+      auto enumName = typedefType->getDecl()->getName();
+      ArgumentAttrs argumentAttrs(DefaultArgumentKind::None, true, enumName);
+      auto camelCaseWords = camel_case::getWords(enumName);
+      for (auto it = camelCaseWords.rbegin(); it != camelCaseWords.rend();
+           ++it) {
+        auto word = *it;
+        auto next = std::next(it);
+        if (camel_case::sameWordIgnoreFirstCase(word, "options")) {
+          argumentAttrs.argumentKind = DefaultArgumentKind::EmptyArray;
+          return argumentAttrs;
         }
+        if (camel_case::sameWordIgnoreFirstCase(word, "units"))
+          return argumentAttrs;
+        if (camel_case::sameWordIgnoreFirstCase(word, "domain"))
+          return argumentAttrs;
+        if (camel_case::sameWordIgnoreFirstCase(word, "action"))
+          return argumentAttrs;
+        if (camel_case::sameWordIgnoreFirstCase(word, "event"))
+          return argumentAttrs;
+        if (camel_case::sameWordIgnoreFirstCase(word, "events") &&
+            next != camelCaseWords.rend() &&
+            camel_case::sameWordIgnoreFirstCase(*next, "control"))
+          return argumentAttrs;
+        if (camel_case::sameWordIgnoreFirstCase(word, "state"))
+          return argumentAttrs;
+        if (camel_case::sameWordIgnoreFirstCase(word, "unit"))
+          return argumentAttrs;
+        if (camel_case::sameWordIgnoreFirstCase(word, "position") &&
+            next != camelCaseWords.rend() &&
+            camel_case::sameWordIgnoreFirstCase(*next, "scroll"))
+          return argumentAttrs;
+        if (camel_case::sameWordIgnoreFirstCase(word, "edge"))
+          return argumentAttrs;
       }
     }
   }

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

@@ -9,10 +9,6 @@ module CxxClassWithNSStringInit {
   requires cplusplus
 }
 
-module CustomNSOptions {
-  header "customNSOptions.h"
-}
-
 module NSOptionsMangling {
   header "NSOptionsMangling.h"
 }