Index: libcxx/trunk/CMakeLists.txt
===================================================================
--- libcxx/trunk/CMakeLists.txt
+++ libcxx/trunk/CMakeLists.txt
@@ -119,7 +119,8 @@
           ${LLVM_MAIN_SRC_DIR}/runtimes/libcxxabi/include
     NO_DEFAULT_PATH
   )
-  if (IS_DIRECTORY "${LIBCXX_LIBCXXABI_INCLUDES_INTERNAL}")
+  if ((NOT LIBCXX_STANDALONE_BUILD OR HAVE_LIBCXXABI) AND
+      IS_DIRECTORY "${LIBCXX_LIBCXXABI_INCLUDES_INTERNAL}")
     set(LIBCXX_CXX_ABI_LIBNAME "libcxxabi")
     set(LIBCXX_CXX_ABI_INCLUDE_PATHS "${LIBCXX_LIBCXXABI_INCLUDES_INTERNAL}")
     set(LIBCXX_CXX_ABI_INTREE 1)