1 files changed, 40 insertions, 0 deletions
diff --git a/test/Modules/adl.cpp b/test/Modules/adl.cpp
new file mode 100644
index 000000000000..a1055a889d00
--- /dev/null
+++ b/test/Modules/adl.cpp
@@ -0,0 +1,40 @@
+// RUN: %clang_cc1 -fmodules -verify -fno-modules-error-recovery -fno-spell-checking %s
+// RUN: %clang_cc1 -fmodules -verify -fno-modules-error-recovery -DONLY_Y %s
+
+#pragma clang module build a
+module a {
+  explicit module x {}
+  explicit module y {}
+}
+#pragma clang module contents
+#pragma clang module begin a.x
+namespace N {
+  template<typename T> extern int f(T) { return 0; }
+}
+#pragma clang module end
+
+#pragma clang module begin a.y
+#pragma clang module import a.x
+using N::f;
+#pragma clang module end
+#pragma clang module endbuild
+
+namespace N { struct A {}; }
+struct B {};
+
+#ifndef ONLY_Y
+#pragma clang module import a.x
+void test1() {
+  f(N::A());
+  f(B()); // expected-error {{use of undeclared identifier 'f'}}
+}
+#else
+// expected-no-diagnostics
+#endif
+
+#pragma clang module import a.y
+void test2() {
+  // These are OK even if a.x is not imported.
+  f(N::A());
+  f(B());
+}