[modules] If a module #includes a modular header that #undef's its macro, it

should not export the macro.

... at least, not unless we have local submodule visibility enabled.

llvm-svn: 236369

4 files changed, 23 insertions, 0 deletions

diff --git a/clang/test/Modules/Inputs/macro-masking/a.h b/clang/test/Modules/Inputs/macro-masking/a.h
new file mode 100644
index 00000000000..dbc17b8cbcf
--- /dev/null
+++ b/clang/test/Modules/Inputs/macro-masking/a.h
@@ -0,0 +1,2 @@
+#define MACRO
+#include "b.h"
diff --git a/clang/test/Modules/Inputs/macro-masking/b.h b/clang/test/Modules/Inputs/macro-masking/b.h
new file mode 100644
index 00000000000..0d14daf13af
--- /dev/null
+++ b/clang/test/Modules/Inputs/macro-masking/b.h
@@ -0,0 +1 @@
+#undef MACRO
diff --git a/clang/test/Modules/Inputs/macro-masking/module.modulemap b/clang/test/Modules/Inputs/macro-masking/module.modulemap
new file mode 100644
index 00000000000..63e1014dda8
--- /dev/null
+++ b/clang/test/Modules/Inputs/macro-masking/module.modulemap
@@ -0,0 +1,4 @@
+module X {
+  module A { header "a.h" export * }
+  module B { header "b.h" export * }
+}
diff --git a/clang/test/Modules/macro-masking.cpp b/clang/test/Modules/macro-masking.cpp
new file mode 100644
index 00000000000..3d4e8e0ba49
--- /dev/null
+++ b/clang/test/Modules/macro-masking.cpp
@@ -0,0 +1,16 @@
+// RUN: rm -rf %t
+// RUN: %clang_cc1 -fsyntax-only -fmodules %s -fmodules-cache-path=%t -verify -I%S/Inputs/macro-masking
+// RxN: %clang_cc1 -fsyntax-only -fmodules -fmodules-local-submodule-visibility %s -fmodules-cache-path=%t -verify -I%S/Inputs/macro-masking -DLOCAL_VISIBILITY
+// expected-no-diagnostics
+
+#include "a.h"
+
+#ifdef LOCAL_VISIBILITY
+# ifndef MACRO
+#  error should still be defined, undef does not override define
+# endif
+#else
+# ifdef MACRO
+#  error should have been undefined!
+# endif
+#endif