Fix a nasty corner case that Neil noticed in PR1900, where we would
incorrectly apply the multiple include optimization to files with
guards like:
#if !defined(x) MACRO
where MACRO could expand to different things in different contexts.
Thanks Neil!
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@45716 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Preprocessor/mi_opt.c b/test/Preprocessor/mi_opt.c
new file mode 100644
index 0000000..96029dc
--- /dev/null
+++ b/test/Preprocessor/mi_opt.c
@@ -0,0 +1,11 @@
+// RUN: not clang -fsyntax-only %s
+// PR1900
+// This test should get a redefinition error from m_iopt.h: the MI opt
+// shouldn't apply.
+
+#define MACRO
+#include "mi_opt.h"
+#undef MACRO
+#define MACRO || 1
+#include "mi_opt.h"
+