AST: MemberImportVisibility should ignore bridging header modules.

Author: tshortli

lib/AST/NameLookup.cpp

@@ -2259,6 +2259,48 @@ void NominalTypeDecl::recordObjCMethod(AbstractFunctionDecl *method,
   vec.push_back(method);
 }
 
+static bool missingExplicitImportForMemberDecl(const DeclContext *dc,
+                                               ValueDecl *decl) {
+  // Only require explicit imports for members when MemberImportVisibility is
+  // enabled.
+  if (!dc->getASTContext().LangOpts.hasFeature(Feature::MemberImportVisibility))
+    return false;
+
+  // If the decl is in the same module, no import is required.
+  auto declModule = decl->getDeclContext()->getParentModule();
+  if (declModule == dc->getParentModule())
+    return false;
+
+  // Source files are not expected to contain an import for the clang header
+  // module.
+  if (auto *loader = dc->getASTContext().getClangModuleLoader()) {
+    if (declModule == loader->getImportedHeaderModule())
+      return false;
+  }
+
+  // Only require an import in the context of user authored source file.
+  auto sf = dc->getParentSourceFile();
+  if (!sf)
+    return false;
+
+  switch (sf->Kind) {
+  case SourceFileKind::SIL:
+  case SourceFileKind::Interface:
+  case SourceFileKind::MacroExpansion:
+  case SourceFileKind::DefaultArgument:
+    return false;
+  case SourceFileKind::Library:
+  case SourceFileKind::Main:
+    break;
+  }
+
+  // If we've found an import, we're done.
+  if (decl->findImport(dc))
+    return false;
+
+  return true;
+}
+
 /// Determine whether the given declaration is an acceptable lookup
 /// result when searching from the given DeclContext.
 static bool isAcceptableLookupResult(const DeclContext *dc,
@@ -2291,10 +2333,7 @@ static bool isAcceptableLookupResult(const DeclContext *dc,
 
     // Check that there is some import in the originating context that
     // makes this decl visible.
-    if (decl->getDeclContext()->getParentModule() != dc->getParentModule() &&
-        dc->getASTContext().LangOpts.hasFeature(
-            Feature::MemberImportVisibility) &&
-        !decl->findImport(dc))
+    if (missingExplicitImportForMemberDecl(dc, decl))
       return false;
   }
 

test/NameLookup/Inputs/Categories/Bridging.h

@@ -0,0 +1,9 @@
+@import Categories_A;
+
+@interface X (BridgingHeader)
+- (void)fromBridgingHeader;
+@end
+
+struct StructInBridgingHeader {
+  int member;
+};

test/NameLookup/members_transitive_objc.swift

@@ -3,7 +3,7 @@
 // RUN: %target-swift-frontend -emit-module -I %t -I %S/Inputs/Categories -o %t %S/Inputs/Categories/Categories_B.swift
 // RUN: %target-swift-frontend -emit-module -I %t -I %S/Inputs/Categories -o %t %S/Inputs/Categories/Categories_C.swift
 // RUN: %target-swift-frontend -emit-module -I %t -I %S/Inputs/Categories -o %t %S/Inputs/Categories/Categories_E.swift
-// RUN: %target-swift-frontend -typecheck %s -I %t -I %S/Inputs/Categories -verify -enable-experimental-feature MemberImportVisibility
+// RUN: %target-swift-frontend -typecheck %s -I %t -I %S/Inputs/Categories -import-objc-header %S/Inputs/Categories/Bridging.h -verify -enable-experimental-feature MemberImportVisibility
 
 // REQUIRES: objc_interop
 
@@ -20,6 +20,7 @@ func test(x: X) {
   x.fromC() // expected-error {{class method 'fromC()' is not available due to missing import of defining module 'Categories_C'}}
   x.fromOverlayForC() // expected-error {{instance method 'fromOverlayForC()' is not available due to missing import of defining module 'Categories_C'}}
   x.fromSubmoduleOfD() // expected-error {{class method 'fromSubmoduleOfD()' is not available due to missing import of defining module 'Categories_D'}}
+  x.fromBridgingHeader()
 }
 
 func testAnyObject(a: AnyObject) {
@@ -32,4 +33,15 @@ func testAnyObject(a: AnyObject) {
   // `MemberImportVisibility` has no effect on these diagnostics.
   a.fromC() // expected-error {{value of type 'AnyObject' has no member 'fromC'}}
   a.fromOverlayForCObjC() // expected-error {{value of type 'AnyObject' has no member 'fromOverlayForCObjC'}}
+  a.fromBridgingHeader()
+}
+
+extension StructInBridgingHeader {
+  init(_ x: Int32) {
+    self.init(member: x)
+  }
+
+  var wrappedMember: Int32 {
+    return member
+  }
 }