diff -Naur osl/src/external_osl/src/cmake/flexbison.cmake osl_bak/src/external_osl/src/cmake/flexbison.cmake
--- osl/src/external_osl//src/cmake/flexbison.cmake	2016-01-29 11:15:22 -0700
+++ osl_bak/src/external_osl/src/cmake/flexbison.cmake	2016-02-29 21:26:26 -0700
@@ -77,7 +77,7 @@
           DEPENDS ${${compiler_headers}}
           WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} )
         ADD_CUSTOM_COMMAND ( OUTPUT ${flexoutputcxx} 
-          COMMAND ${FLEX_EXECUTABLE} -o ${flexoutputcxx} "${CMAKE_CURRENT_SOURCE_DIR}/${flexsrc}"
+          COMMAND ${FLEX_EXECUTABLE} ${FLEX_EXTRA_OPTIONS} -o ${flexoutputcxx} "${CMAKE_CURRENT_SOURCE_DIR}/${flexsrc}"
           MAIN_DEPENDENCY ${flexsrc}
           DEPENDS ${${compiler_headers}}
           WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} )
--- osl/src/external_osl/src/include/OSL/oslconfig.h	2016-10-31 16:48:19 -0600
+++ osl/src/external_osl/src/include/OSL/oslconfig.h	2018-05-27 11:18:08 -0600
@@ -44,12 +44,18 @@
 // same if another packages is compiling against OSL and using these headers
 // (OSL may be C++11 but the client package may be older, or vice versa --
 // use these two symbols to differentiate these cases, when important).
-#if (__cplusplus >= 201402L)
-#  define OSL_CPLUSPLUS_VERSION  14
-#elif (__cplusplus >= 201103L)
-#  define OSL_CPLUSPLUS_VERSION  11
+
+// Force C++03 for MSVC in blender since svn the libraries are build with that
+#if !defined(_MSC_VER)
+	#if (__cplusplus >= 201402L)
+	#  define OSL_CPLUSPLUS_VERSION  14
+	#elif (__cplusplus >= 201103L)
+	#  define OSL_CPLUSPLUS_VERSION  11
+	#else
+	#  define OSL_CPLUSPLUS_VERSION  3 /* presume C++03 */
+	#endif
 #else
-#  define OSL_CPLUSPLUS_VERSION  3 /* presume C++03 */
+	#  define OSL_CPLUSPLUS_VERSION  3 /* presume C++03 */
 #endif
 
 // Symbol export defines