Do not warn on keyword undef

#undef a keyword is generally harmless but used often in configuration scripts.
Also added tests that I forgot to include to commit in r223114.

llvm-svn: 224100

1 files changed, 25 insertions, 0 deletions

diff --git a/clang/test/Preprocessor/macro-reserved.c b/clang/test/Preprocessor/macro-reserved.c
new file mode 100644
index 00000000000..2a0e26f8e3a
--- /dev/null
+++ b/clang/test/Preprocessor/macro-reserved.c
@@ -0,0 +1,25 @@
+// RUN: %clang_cc1 -fsyntax-only %s -verify
+
+#define for 0    // expected-warning {{keyword is hidden by macro definition}}
+#define final 1
+#define __HAVE_X 0
+#define _HAVE_X 0
+#define X__Y
+
+#undef __cplusplus
+#undef _HAVE_X
+#undef X__Y
+
+#pragma clang diagnostic warning "-Wreserved-id-macro"
+
+#define switch if  // expected-warning {{keyword is hidden by macro definition}}
+#define final 1
+#define __HAVE_X 0 // expected-warning {{macro name is a reserved identifier}}
+#define _HAVE_X 0  // expected-warning {{macro name is a reserved identifier}}
+#define X__Y
+
+#undef __cplusplus // expected-warning {{macro name is a reserved identifier}}
+#undef _HAVE_X     // expected-warning {{macro name is a reserved identifier}}
+#undef X__Y
+
+int x;