Index: cfe/trunk/lib/Frontend/InitPreprocessor.cpp
===================================================================
--- cfe/trunk/lib/Frontend/InitPreprocessor.cpp
+++ cfe/trunk/lib/Frontend/InitPreprocessor.cpp
@@ -491,7 +491,7 @@
     Builder.defineMacro("__BLOCKS__");
   }
 
-  if (LangOpts.CXXExceptions)
+  if (!LangOpts.MSVCCompat && LangOpts.CXXExceptions)
     Builder.defineMacro("__EXCEPTIONS");
   if (LangOpts.RTTI)
     Builder.defineMacro("__GXX_RTTI");
Index: cfe/trunk/test/Frontend/exceptions.c
===================================================================
--- cfe/trunk/test/Frontend/exceptions.c
+++ cfe/trunk/test/Frontend/exceptions.c
@@ -0,0 +1,6 @@
+// RUN: %clang_cc1 -fms-compatibility -fexceptions -fcxx-exceptions -verify %s
+// expected-no-diagnostics
+
+#if defined(__EXCEPTIONS)
+#error __EXCEPTIONS should not be defined.
+#endif