Revert "AST: Filter out some Obj-C overrides when MemberImportVisibility is enabled."

This reverts commit 324fa23.

Author: tshortli

lib/AST/NameLookup.cpp

@@ -2388,8 +2388,6 @@ static bool isAcceptableLookupResult(const DeclContext *dc, NLOptions options,
                                      ValueDecl *decl,
                                      bool onlyCompleteObjectInits,
                                      bool requireImport) {
-  auto &ctx = dc->getASTContext();
-
   // Filter out designated initializers, if requested.
   if (onlyCompleteObjectInits) {
     if (auto ctor = dyn_cast<ConstructorDecl>(decl)) {
@@ -2407,43 +2405,19 @@ static bool isAcceptableLookupResult(const DeclContext *dc, NLOptions options,
   }
 
   // Check access.
-  if (!(options & NL_IgnoreAccessControl) && !ctx.isAccessControlDisabled()) {
+  if (!(options & NL_IgnoreAccessControl) &&
+      !dc->getASTContext().isAccessControlDisabled()) {
     bool allowUsableFromInline = options & NL_IncludeUsableFromInline;
     if (!decl->isAccessibleFrom(dc, /*forConformance*/ false,
                                 allowUsableFromInline))
       return false;
   }
 
-  if (requireImport) {
-    // Check that there is some import in the originating context that makes
-    // this decl visible.
-    if (!(options & NL_IgnoreMissingImports)) {
-      if (!dc->isDeclImported(decl))
-        return false;
-    }
-
-    // Unlike in Swift, Obj-C allows method overrides to be declared in
-    // extensions (categories), even outside of the module that defines the
-    // type that is being extended. When MemberImportVisibility is enabled,
-    // if these overrides are not filtered out they can hijack name
-    // lookup and cause the compiler to insist that the module that defines
-    // the extension be imported, contrary to developer expectations.
-    //
-    // Filter results belonging to these extensions out, even when ignoring
-    // missing imports, if we're in a context that requires imports to access
-    // member declarations.
-    if (decl->getOverriddenDecl()) {
-      if (auto *extension = dyn_cast<ExtensionDecl>(decl->getDeclContext())) {
-        if (auto *nominal = extension->getExtendedNominal()) {
-          auto extensionMod = extension->getModuleContext();
-          auto nominalMod = nominal->getModuleContext();
-          if (!extensionMod->isSameModuleLookingThroughOverlays(nominalMod) &&
-              !dc->isDeclImported(extension))
-            return false;
-        }
-      }
-    }
-  }
+  // Check that there is some import in the originating context that makes this
+  // decl visible.
+  if (requireImport && !(options & NL_IgnoreMissingImports))
+    if (!dc->isDeclImported(decl))
+      return false;
 
   // Check that it has the appropriate ABI role.
   if (!ABIRoleInfo(decl).matchesOptions(options))

test/NameLookup/Inputs/MemberImportVisibility/Categories_A.h

@@ -1,13 +1,6 @@
 @import Foundation;
 
-@interface Base
-- (void)overriddenInOverlayForA __attribute__((deprecated("Categories_A.h")));
-- (void)overriddenInOverlayForB __attribute__((deprecated("Categories_A.h")));
-- (void)overriddenInOverlayForC __attribute__((deprecated("Categories_A.h")));
-- (void)overriddenInSubclassInOverlayForC __attribute__((deprecated("Categories_A.h")));
-@end
-
-@interface X : Base
+@interface X
 @end
 
 @interface X (A)

test/NameLookup/Inputs/MemberImportVisibility/Categories_A.swift

@@ -3,7 +3,4 @@
 extension X {
   public func fromOverlayForA() {}
   @objc public func fromOverlayForAObjC() {}
-
-  @available(*, deprecated, message: "Categories_A.swift")
-  public override func overriddenInOverlayForA() {}
 }

test/NameLookup/Inputs/MemberImportVisibility/Categories_B.swift

@@ -3,7 +3,4 @@
 extension X {
   public func fromOverlayForB() {}
   @objc public func fromOverlayForBObjC() {}
-
-  @available(*, deprecated, message: "Categories_B.swift")
-  public override func overriddenInOverlayForB() {}
 }

test/NameLookup/Inputs/MemberImportVisibility/Categories_C.h

@@ -3,7 +3,3 @@
 @interface X (C)
 - (void)fromC;
 @end
-
-@interface SubclassFromC : X
-- (instancetype)init;
-@end

test/NameLookup/Inputs/MemberImportVisibility/Categories_C.swift

@@ -3,12 +3,4 @@
 extension X {
   public func fromOverlayForC() {}
   @objc public func fromOverlayForCObjC() {}
-
-  @available(*, deprecated, message: "Categories_C.swift")
-  public override func overriddenInOverlayForC() {}
-}
-
-extension SubclassFromC {
-  @available(*, deprecated, message: "Categories_C.swift")
-  public override func overriddenInSubclassInOverlayForC() {}
 }

test/NameLookup/Inputs/MemberImportVisibility/Categories_E.swift

@@ -1,4 +1,2 @@
 import Categories_C
 import Categories_D.Submodule
-
-public func makeSubclassFromC() -> SubclassFromC { SubclassFromC() }