1 files changed, 65 insertions, 0 deletions
diff --git a/clang/test/Modules/befriend-2.cppm b/clang/test/Modules/befriend-2.cppm
new file mode 100644
index 000000000000..9d0baf849cad
--- /dev/null
+++ b/clang/test/Modules/befriend-2.cppm
@@ -0,0 +1,65 @@
+// RUN: rm -rf %t
+// RUN: mkdir -p %t
+// RUN: split-file %s %t
+//
+// RUN: %clang_cc1 -std=c++20 %t/a.cppm -emit-reduced-module-interface -o %t/test-A.pcm
+// RUN: %clang_cc1 -std=c++20 %t/N.cppm -emit-reduced-module-interface -o %t/test-N.pcm
+// RUN: %clang_cc1 -std=c++20 %t/B.cppm -verify -fsyntax-only -fprebuilt-module-path=%t
+
+//--- a.h
+namespace N {
+
+    template <typename>
+    class C {
+    template <typename> friend void foo();
+    };
+
+    template <typename> void foo() {}
+} // namespace N
+
+//--- a.cppm
+// This is some unrelated file. It also #includes system headers, but
+// here does not even export anything.
+module;
+#include "a.h"
+export module test:A;
+export {
+    using N::C;
+    using N::foo;
+}
+
+//--- std.h
+// Declarations typically #included from C++ header files:
+namespace N {               // In practice, this would be namespace std
+    inline namespace impl {   // In practice, this would be namespace __1
+        template <typename>
+        class C {
+        template <typename> friend void foo();
+        };
+    
+        template <typename> void foo() {}
+    } // namespace impl
+    } // namespace N
+
+//--- N.cppm
+module;
+#include "std.h"
+export module test:N;
+
+// Now wrap these names into a module and export them:
+export {
+    namespace N   {
+        using N::C;
+        using N::foo;
+    }
+}
+
+//--- B.cppm
+// expected-no-diagnostics
+// A file that consumes the partitions from the other two files,
+// including the exported N::C name.
+module test:B;
+import :N;
+import :A;
+
+N::C<int> x;