diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -2220,6 +2220,9 @@
   /// The modules we're currently parsing.
   llvm::SmallVector<ModuleScope, 16> ModuleScopes;
 
+  /// The modules we imported directly.
+  llvm::SmallPtrSet<clang::Module *, 8> DirectModuleImports;
+
   /// Namespace definitions that we will export when they finish.
   llvm::SmallPtrSet<const NamespaceDecl*, 8> DeferredExportedNamespaces;
 
@@ -2247,6 +2250,10 @@
     return Entity->getOwningModule();
   }
 
+  bool isModuleDirectlyImported(const Module *M) {
+    return DirectModuleImports.contains(M);
+  }
+
   /// Make a merged definition of an existing hidden definition \p ND
   /// visible at the specified location.
   void makeMergedDefinitionVisible(NamedDecl *ND);
diff --git a/clang/lib/Sema/SemaModule.cpp b/clang/lib/Sema/SemaModule.cpp
--- a/clang/lib/Sema/SemaModule.cpp
+++ b/clang/lib/Sema/SemaModule.cpp
@@ -434,6 +434,10 @@
          << !ModuleScopes.back().ModuleInterface;
   }
 
+  // In some cases we need to know if an entity was present in a directly-
+  // imported module (as opposed to a transitive import).
+  DirectModuleImports.insert(Mod);
+
   // FIXME: we should support importing a submodule within a different submodule
   // of the same top-level module. Until we do, make it an error rather than
   // silently ignoring the import.