Index: include/__config
===================================================================
--- include/__config
+++ include/__config
@@ -204,6 +204,10 @@
 #  endif
 #endif
 
+#if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
+# define _LIBCPP_ABI_VCRUNTIME
+#endif
+
 // Need to detect which libc we're using if we're on Linux.
 #if defined(__linux__)
 #  include <features.h>
@@ -989,15 +993,11 @@
 #define _DECLARE_C99_LDBL_MATH 1
 #endif
 
-#if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
-#  define _LIBCPP_DEFER_NEW_TO_VCRUNTIME
-#endif
-
 // If we are getting operator new from the MSVC CRT, then allocation overloads
 // for align_val_t were added in 19.12, aka VS 2017 version 15.3.
 #if defined(_LIBCPP_MSVCRT) && defined(_MSC_VER) && _MSC_VER < 1912
 #  define _LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION
-#elif defined(_LIBCPP_DEFER_NEW_TO_VCRUNTIME) && !defined(__cpp_aligned_new)
+#elif defined(_LIBCPP_ABI_VCRUNTIME) && !defined(__cpp_aligned_new)
    // We're defering to Microsoft's STL to provide aligned new et al. We don't
    // have it unless the language feature test macro is defined.
 #  define _LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION
Index: include/exception
===================================================================
--- include/exception
+++ include/exception
@@ -82,7 +82,7 @@
 #include <type_traits>
 #include <version>
 
-#if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
+#if defined(_LIBCPP_ABI_VCRUNTIME)
 #include <vcruntime_exception.h>
 #endif
 
@@ -93,7 +93,7 @@
 namespace std  // purposefully not using versioning namespace
 {
 
-#if !defined(_LIBCPP_ABI_MICROSOFT) || defined(_LIBCPP_NO_VCRUNTIME)
+#if !defined(_LIBCPP_ABI_VCRUNTIME)
 class _LIBCPP_EXCEPTION_ABI exception
 {
 public:
@@ -110,7 +110,7 @@
     virtual ~bad_exception() _NOEXCEPT;
     virtual const char* what() const _NOEXCEPT;
 };
-#endif // !_LIBCPP_ABI_MICROSOFT || _LIBCPP_NO_VCRUNTIME
+#endif // !_LIBCPP_ABI_VCRUNTIME
 
 #if _LIBCPP_STD_VER <= 14 \
     || defined(_LIBCPP_ENABLE_CXX17_REMOVED_UNEXPECTED_FUNCTIONS) \
Index: include/new
===================================================================
--- include/new
+++ include/new
@@ -89,7 +89,7 @@
 #include <cstdlib>
 #endif
 
-#if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
+#if defined(_LIBCPP_ABI_VCRUNTIME)
 #include <new.h>
 #endif
 
@@ -119,7 +119,7 @@
 namespace std  // purposefully not using versioning namespace
 {
 
-#if !defined(_LIBCPP_ABI_MICROSOFT) || defined(_LIBCPP_NO_VCRUNTIME)
+#if !defined(_LIBCPP_ABI_VCRUNTIME)
 struct _LIBCPP_TYPE_VIS nothrow_t {};
 extern _LIBCPP_FUNC_VIS const nothrow_t nothrow;
 
@@ -145,12 +145,12 @@
 _LIBCPP_FUNC_VIS new_handler set_new_handler(new_handler) _NOEXCEPT;
 _LIBCPP_FUNC_VIS new_handler get_new_handler() _NOEXCEPT;
 
-#endif // !_LIBCPP_ABI_MICROSOFT || _LIBCPP_NO_VCRUNTIME
+#endif // !_LIBCPP_ABI_VCRUNTIME
 
 _LIBCPP_NORETURN _LIBCPP_FUNC_VIS void __throw_bad_alloc();  // not in C++ spec
 
 #if !defined(_LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION) && \
-    !defined(_LIBCPP_DEFER_NEW_TO_VCRUNTIME)
+    !defined(_LIBCPP_ABI_VCRUNTIME)
 #ifndef _LIBCPP_CXX03_LANG
 enum class _LIBCPP_ENUM_VIS align_val_t : size_t { };
 #else
@@ -166,7 +166,7 @@
 #define _THROW_BAD_ALLOC
 #endif
 
-#if !defined(_LIBCPP_DEFER_NEW_TO_VCRUNTIME)
+#if !defined(_LIBCPP_ABI_VCRUNTIME)
 
 _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz) _THROW_BAD_ALLOC;
 _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz, const std::nothrow_t&) _NOEXCEPT _LIBCPP_NOALIAS;
@@ -207,7 +207,7 @@
 inline _LIBCPP_INLINE_VISIBILITY void  operator delete  (void*, void*) _NOEXCEPT {}
 inline _LIBCPP_INLINE_VISIBILITY void  operator delete[](void*, void*) _NOEXCEPT {}
 
-#endif // !_LIBCPP_DEFER_NEW_TO_VCRUNTIME
+#endif // !_LIBCPP_ABI_VCRUNTIME
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
Index: include/typeinfo
===================================================================
--- include/typeinfo
+++ include/typeinfo
@@ -68,7 +68,7 @@
 #pragma GCC system_header
 #endif
 
-#if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
+#if defined(_LIBCPP_ABI_VCRUNTIME)
 #include <vcruntime_typeinfo.h>
 #else
 
@@ -262,7 +262,7 @@
 
 }  // std
 
-#endif // defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
+#endif // defined(_LIBCPP_ABI_VCRUNTIME)
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 _LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
Index: src/new.cpp
===================================================================
--- src/new.cpp
+++ src/new.cpp
@@ -12,7 +12,7 @@
 #include "include/atomic_support.h"
 
 #if defined(_LIBCPP_ABI_MICROSOFT)
-#if defined(_LIBCPP_NO_VCRUNTIME)
+#if !defined(_LIBCPP_ABI_VCRUNTIME)
 #include "support/runtime/new_handler_fallback.ipp"
 #endif
 #elif defined(LIBCXX_BUILDING_LIBCXXABI)
@@ -54,7 +54,7 @@
 }  // std
 
 #if !defined(__GLIBCXX__) &&                                                   \
-    !defined(_LIBCPP_DEFER_NEW_TO_VCRUNTIME) &&      \
+    !defined(_LIBCPP_ABI_VCRUNTIME) &&      \
     !defined(_LIBCPP_DISABLE_NEW_DELETE_DEFINITIONS)
 
 // Implement all new and delete operators as weak definitions
@@ -298,4 +298,4 @@
 }
 
 #endif // !_LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION
-#endif // !__GLIBCXX__ && (!_LIBCPP_ABI_MICROSOFT || _LIBCPP_NO_VCRUNTIME) && !_LIBCPP_DISABLE_NEW_DELETE_DEFINITIONS
+#endif // !__GLIBCXX__ && !_LIBCPP_ABI_VCRUNTIME && !_LIBCPP_DISABLE_NEW_DELETE_DEFINITIONS
Index: src/stdexcept.cpp
===================================================================
--- src/stdexcept.cpp
+++ src/stdexcept.cpp
@@ -77,7 +77,7 @@
     return __imp_.c_str();
 }
 
-#if !defined(_LIBCPP_ABI_MICROSOFT) || defined(_LIBCPP_NO_VCRUNTIME)
+#if !defined(_LIBCPP_ABI_VCRUNTIME)
 
 logic_error::~logic_error() _NOEXCEPT {}
 domain_error::~domain_error() _NOEXCEPT {}
Index: src/support/runtime/exception_msvc.ipp
===================================================================
--- src/support/runtime/exception_msvc.ipp
+++ src/support/runtime/exception_msvc.ipp
@@ -82,7 +82,7 @@
     return __uncaught_exceptions();
 }
 
-#if defined(_LIBCPP_NO_VCRUNTIME)
+#if !defined(_LIBCPP_ABI_VCRUNTIME)
 bad_cast::bad_cast() _NOEXCEPT
 {
 }
@@ -158,6 +158,6 @@
 {
     return "bad_array_new_length";
 }
-#endif // _LIBCPP_NO_VCRUNTIME
+#endif // !_LIBCPP_ABI_VCRUNTIME
 
 } // namespace std
Index: src/typeinfo.cpp
===================================================================
--- src/typeinfo.cpp
+++ src/typeinfo.cpp
@@ -8,7 +8,7 @@
 
 #include "typeinfo"
 
-#if defined(_LIBCPP_ABI_MICROSOFT) && defined(_LIBCPP_NO_VCRUNTIME)
+#if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_ABI_VCRUNTIME)
 #include <string.h>
 
 int std::type_info::__compare(const type_info &__rhs) const _NOEXCEPT {
@@ -49,7 +49,7 @@
 // FIXME: Remove the _LIBCPP_BUILDING_HAS_NO_ABI_LIBRARY configuration.
 #if (!defined(LIBCXX_BUILDING_LIBCXXABI) && !defined(LIBCXXRT) &&              \
      !defined(__GLIBCXX__) && !defined(__APPLE__) &&                           \
-     !(defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME))) ||   \
+     !defined(_LIBCPP_ABI_VCRUNTIME)) ||   \
     defined(_LIBCPP_BUILDING_HAS_NO_ABI_LIBRARY)
 std::type_info::~type_info()
 {