Index: CMakeLists.txt
===================================================================
--- CMakeLists.txt
+++ CMakeLists.txt
@@ -249,6 +249,10 @@
   list(APPEND LIBCXXABI_LINK_FLAGS "-rtlib=compiler-rt")
 endif()
 
+# Let the library headers know they are currently being used to build the
+# library.
+add_definitions(-D_LIBCXXABI_BUILDING_LIBRARY)
+
 append_if(LIBCXXABI_COMPILE_FLAGS LIBCXXABI_HAS_WERROR_FLAG -Werror=return-type)
 
 # Get warning flags
@@ -333,7 +337,6 @@
   add_definitions(-D_LIBCPP_HAS_THREAD_API_PTHREAD)
 endif()
 
-# This is the _ONLY_ place where add_definitions is called.
 if (MSVC)
   add_definitions(-D_CRT_SECURE_NO_WARNINGS)
 endif()
Index: include/__cxxabi_config.h
===================================================================
--- include/__cxxabi_config.h
+++ include/__cxxabi_config.h
@@ -21,8 +21,13 @@
 #define __has_attribute(_attribute_) 0
 #endif
 
-#if defined(_LIBCXXABI_DLL)
- #if defined(cxxabi_EXPORTS)
+#if defined(_WIN32)
+ #if defined(_LIBCXXABI_DISABLE_DLL_IMPORT_EXPORT)
+  #define _LIBCXXABI_HIDDEN
+  #define _LIBCXXABI_DATA_VIS
+  #define _LIBCXXABI_FUNC_VIS
+  #define _LIBCXXABI_TYPE_VIS
+ #elif defined(_LIBCXXABI_BUILDING_LIBRARY)
   #define _LIBCXXABI_HIDDEN
   #define _LIBCXXABI_DATA_VIS __declspec(dllexport)
   #define _LIBCXXABI_FUNC_VIS __declspec(dllexport)