Index: llvm/trunk/CMakeLists.txt
===================================================================
--- llvm/trunk/CMakeLists.txt
+++ llvm/trunk/CMakeLists.txt
@@ -530,6 +530,8 @@
 endif()
 option(LLVM_BUILD_LLVM_DYLIB "Build libllvm dynamic library" ${LLVM_BUILD_LLVM_DYLIB_default})
 
+option(LLVM_DYLIB_SYMBOL_VERSIONING OFF)
+
 option(LLVM_OPTIMIZED_TABLEGEN "Force TableGen to be built with optimization" OFF)
 if(CMAKE_CROSSCOMPILING OR (LLVM_OPTIMIZED_TABLEGEN AND (LLVM_ENABLE_ASSERTIONS OR CMAKE_CONFIGURATION_TYPES)))
   set(LLVM_USE_HOST_TOOLS ON)
Index: llvm/trunk/tools/llvm-shlib/CMakeLists.txt
===================================================================
--- llvm/trunk/tools/llvm-shlib/CMakeLists.txt
+++ llvm/trunk/tools/llvm-shlib/CMakeLists.txt
@@ -50,6 +50,10 @@
 
 target_link_libraries(LLVM PRIVATE ${LIB_NAMES})
 
+if (LLVM_DYLIB_SYMBOL_VERSIONING)
+  set_property(TARGET LLVM APPEND_STRING PROPERTY LINK_FLAGS " -Wl,--default-symver")
+endif()
+
 if (APPLE)
   set_property(TARGET LLVM APPEND_STRING PROPERTY
               LINK_FLAGS