Merge pull request #80563 from tshortli/member-import-visibility-objc-overloads-in-extensions

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

Author: tshortli

lib/AST/NameLookup.cpp

@@ -2388,6 +2388,8 @@ 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)) {
@@ -2405,19 +2407,43 @@ static bool isAcceptableLookupResult(const DeclContext *dc, NLOptions options,
   }
 
   // Check access.
-  if (!(options & NL_IgnoreAccessControl) &&
-      !dc->getASTContext().isAccessControlDisabled()) {
+  if (!(options & NL_IgnoreAccessControl) && !ctx.isAccessControlDisabled()) {
     bool allowUsableFromInline = options & NL_IncludeUsableFromInline;
     if (!decl->isAccessibleFrom(dc, /*forConformance*/ false,
                                 allowUsableFromInline))
       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;
+  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 it has the appropriate ABI role.
   if (!ABIRoleInfo(decl).matchesOptions(options))

test/NameLookup/Inputs/MemberImportVisibility/Categories_A.h

@@ -1,6 +1,13 @@
 @import Foundation;
 
-@interface X
+@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
 @end
 
 @interface X (A)

test/NameLookup/Inputs/MemberImportVisibility/Categories_A.swift

@@ -3,4 +3,7 @@
 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

@@ -3,4 +3,7 @@
 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

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

test/NameLookup/Inputs/MemberImportVisibility/Categories_C.swift

@@ -3,4 +3,12 @@
 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

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

test/NameLookup/Inputs/MemberImportVisibility/ObjCOverloads/Branch.h

@@ -0,0 +1,9 @@
+@import Root;
+
+@interface BranchObject : RootObject
+- (void)overridden1 __attribute__((deprecated("Branch.h")));
+@end
+
+@interface BranchObject (Branch)
+- (void)overridden3 __attribute__((deprecated("Branch.h")));
+@end

test/NameLookup/Inputs/MemberImportVisibility/ObjCOverloads/Fruit.h

@@ -0,0 +1,5 @@
+@import Branch;
+
+@interface FruitObject : BranchObject
+- (void)overridden1 __attribute__((deprecated("Fruit.h")));
+@end

test/NameLookup/Inputs/MemberImportVisibility/ObjCOverloads/Leaf.h

@@ -0,0 +1,14 @@
+@import Branch;
+
+@interface LeafObject : BranchObject
+- (void)overridden1 __attribute__((deprecated("Leaf.h")));
+@end
+
+@interface BranchObject (Leaf)
+- (void)overridden2 __attribute__((deprecated("Leaf.h")));
+@end
+
+@interface LeafObject (Leaf)
+- (void)overridden3 __attribute__((deprecated("Leaf.h")));
+@end
+