diff --git a/src/third_party/llvm-project/clang/test/Modules/preprocess-nested.cpp b/src/third_party/llvm-project/clang/test/Modules/preprocess-nested.cpp
new file mode 100644
index 0000000..f26b655
--- /dev/null
+++ b/src/third_party/llvm-project/clang/test/Modules/preprocess-nested.cpp
@@ -0,0 +1,57 @@
+// RUN: rm -rf %t
+// RUN: mkdir %t
+
+// RUN: %clang_cc1 -fmodules -fmodules-local-submodule-visibility -fmodule-name=nested -I%S/Inputs/preprocess -x c++-module-map %S/Inputs/preprocess/module.modulemap -E -o %t/no-rewrite.ii
+// RUN: %clang_cc1 -fmodules -fmodules-local-submodule-visibility -fmodule-name=nested -I%S/Inputs/preprocess -x c++-module-map %S/Inputs/preprocess/module.modulemap -E -frewrite-includes -o %t/rewrite.ii
+
+// RUN: FileCheck %s --input-file %t/no-rewrite.ii --check-prefix=CHECK --check-prefix=NO-REWRITE
+// RUN: FileCheck %s --input-file %t/rewrite.ii    --check-prefix=CHECK --check-prefix=REWRITE
+
+// Check that we can build a module from the preprocessed output.
+// RUN: %clang_cc1 -fmodules -fmodules-local-submodule-visibility -fmodule-name=nested -x c++-module-map-cpp-output %t/no-rewrite.ii -emit-module -o %t/no-rewrite.pcm
+// RUN: %clang_cc1 -fmodules -fmodules-local-submodule-visibility -fmodule-name=nested -x c++-module-map-cpp-output %t/rewrite.ii -emit-module -o %t/rewrite.pcm
+
+// Check the module we built works.
+// RUN: %clang_cc1 -fmodules -fmodule-file=%t/no-rewrite.pcm %s -I%t -verify -fno-modules-error-recovery
+// RUN: %clang_cc1 -fmodules -fmodule-file=%t/rewrite.pcm %s -I%t -verify -fno-modules-error-recovery -DREWRITE
+
+// == module map
+// CHECK: # 1 "{{.*}}module.modulemap"
+// CHECK: module nested {
+// CHECK:   module a {
+// CHECK:     header "a.h"
+// CHECK:   }
+// CHECK:   module b {
+// CHECK:     header "b.h"
+// CHECK:   }
+// CHECK:   module c {
+// CHECK:     header "c.h"
+// CHECK:   }
+// CHECK: }
+
+// CHECK: #pragma clang module begin nested.a
+// CHECK: #pragma clang module begin nested.c
+// CHECK: using T = int;
+// CHECK: #pragma clang module end
+// CHECK: T a();
+// CHECK: #pragma clang module end
+
+// CHECK: #pragma clang module begin nested.b
+// CHECK: #pragma clang module import nested.c
+// CHECK-NOT: #pragma clang module begin nested.c
+// CHECK-NOT: using T = int;
+// CHECK-NOT: #pragma clang module end
+// CHECK: T b();
+// CHECK: #pragma clang module end
+
+// CHECK: #pragma clang module import nested.c
+
+#pragma clang module import nested.b
+
+int n = b();
+T c; // expected-error {{must be imported}}
+#ifdef REWRITE
+// expected-note@rewrite.ii:* {{declar}}
+#else
+// expected-note@no-rewrite.ii:* {{declar}}
+#endif