Preprocessor: make C++ operator names as macro identifiers a compatible extension

With recent changes, this is now a compatible language extension and can be
safely enabled with -ms-extensions instead of requiring the full
-ms-compatibility MSVC drop-in mode. As such we can now also emit an extension
warning under -Wmicrosoft to help users port their code.

llvm-svn: 209978

1 files changed, 6 insertions, 5 deletions

diff --git a/clang/lib/Lex/PPDirectives.cpp b/clang/lib/Lex/PPDirectives.cpp
index 46e8f07c510..a8dde086baf 100644
--- a/clang/lib/Lex/PPDirectives.cpp
+++ b/clang/lib/Lex/PPDirectives.cpp
@@ -145,11 +145,12 @@ bool Preprocessor::CheckMacroName(Token &MacroNameTok, char isDefineUndef) {
     if (!II->isCPlusPlusOperatorKeyword())
       return Diag(MacroNameTok, diag::err_pp_macro_not_identifier);
 
-    if (!getLangOpts().MSVCCompat)
-      // C++ 2.5p2: Alternative tokens behave the same as its primary token
-      // except for their spellings.
-      Diag(MacroNameTok, diag::err_pp_operator_used_as_macro_name)
-          << II << MacroNameTok.getKind();
+    // C++ 2.5p2: Alternative tokens behave the same as its primary token
+    // except for their spellings.
+    Diag(MacroNameTok, getLangOpts().MicrosoftExt
+                           ? diag::ext_pp_operator_used_as_macro_name
+                           : diag::err_pp_operator_used_as_macro_name)
+        << II << MacroNameTok.getKind();
 
     // Allow #defining |and| and friends for Microsoft compatibility or
     // recovery when legacy C headers are included in C++.