Preprocessor: recover gracefully when C++ operator names are used as macro identifiers

This failure mode shows up occasionally when users try to include C headers in
C++ projects or when porting from Windows. We might as well recover in the way
the user expected, thus avoiding confusing diagnostic messages at point of use.

llvm-svn: 209963

1 files changed, 11 insertions, 2 deletions

diff --git a/clang/test/Preprocessor/cxx_oper_keyword.cpp b/clang/test/Preprocessor/cxx_oper_keyword.cpp
index 03e2a661b97..89a094d073c 100644
--- a/clang/test/Preprocessor/cxx_oper_keyword.cpp
+++ b/clang/test/Preprocessor/cxx_oper_keyword.cpp
@@ -11,12 +11,21 @@
 // Not valid in C++ unless -fno-operator-names is passed:
 
 #ifdef OPERATOR_NAMES
-//expected-error@+2 {{C++ operator 'and' (aka '&&') cannot be used as a macro name}}
+//expected-error@+2 {{C++ operator 'and' (aka '&&') used as a macro name}}
 #endif
 #define and foo
 
 #ifdef OPERATOR_NAMES
-//expected-error@+2 {{C++ operator 'xor' (aka '^') cannot be used as a macro name}}
+//expected-error@+2 {{C++ operator 'xor' (aka '^') used as a macro name}}
 #endif
 #if defined xor
 #endif
+
+// For error recovery we continue as though the identifier was a macro name regardless of -fno-operator-names.
+#ifdef OPERATOR_NAMES
+//expected-error@+3 {{C++ operator 'and' (aka '&&') used as a macro name}}
+#endif
+//expected-warning@+2 {{and is defined}}
+#ifdef and
+#warning and is defined
+#endif