Index: CMakeLists.txt
===================================================================
--- CMakeLists.txt	(revision 191469)
+++ CMakeLists.txt	(working copy)
@@ -181,7 +181,9 @@
 endmacro()
 
 # Get warning flags
-append_if(LIBCXX_CXX_WARNING_FLAGS LIBCXX_HAS_WALL_FLAG -Wall)
+if (NOT MSVC)
+  append_if(LIBCXX_CXX_WARNING_FLAGS LIBCXX_HAS_WALL_FLAG -Wall)
+endif()
 append_if(LIBCXX_CXX_WARNING_FLAGS LIBCXX_HAS_W_FLAG -W)
 append_if(LIBCXX_CXX_WARNING_FLAGS LIBCXX_HAS_WNO_UNUSED_PARAMETER_FLAG -Wno-unused-parameter)
 append_if(LIBCXX_CXX_WARNING_FLAGS LIBCXX_HAS_WWRITE_STRINGS_FLAG -Wwrite-strings)