Index: CMakeLists.txt
===================================================================
--- CMakeLists.txt
+++ CMakeLists.txt
@@ -253,6 +253,26 @@
   endif()
 endif ()
 
+# Determine HOST_LINK_VERSION on Darwin.
+set(HOST_LINK_VERSION)
+if (APPLE)
+  set(LD_V_OUTPUT)
+  execute_process(
+    COMMAND sh -c "${CMAKE_LINKER} -v 2>&1 | head -1"
+    RESULT_VARIABLE HAD_ERROR
+    OUTPUT_VARIABLE LD_V_OUTPUT
+  )
+  if (NOT HAD_ERROR)
+    if ("${LD_V_OUTPUT}" MATCHES ".*ld64.*")
+      string(REGEX REPLACE ".*ld64-([0-9.]*).*" "\\1" HOST_LINK_VERSION ${LD_V_OUTPUT})
+    else()
+      string(REGEX REPLACE "[^0-9]*([0-9.]*).*" "\\1" HOST_LINK_VERSION ${LD_V_OUTPUT})
+    endif()
+  else()
+    message(FATAL_ERROR "${CMAKE_LINKER} failed with status ${HAD_ERROR}")
+  endif()
+endif()
+
 configure_file(
   ${CLANG_SOURCE_DIR}/include/clang/Config/config.h.cmake
   ${CLANG_BINARY_DIR}/include/clang/Config/config.h)
Index: include/clang/Config/config.h.cmake
===================================================================
--- include/clang/Config/config.h.cmake
+++ include/clang/Config/config.h.cmake
@@ -26,4 +26,7 @@
 /* The LLVM product name and version */
 #define BACKEND_PACKAGE_STRING "${BACKEND_PACKAGE_STRING}"
 
+/* Linker version detected at compile time. */
+#cmakedefine HOST_LINK_VERSION "${HOST_LINK_VERSION}"
+
 #endif
Index: include/clang/Config/config.h.in
===================================================================
--- include/clang/Config/config.h.in
+++ include/clang/Config/config.h.in
@@ -14,9 +14,6 @@
 /* Directories clang will search for headers */
 #undef C_INCLUDE_DIRS
 
-/* Linker version detected at compile time. */
-#undef HOST_LINK_VERSION
-
 /* Default <path> to all compiler invocations for --sysroot=<path>. */
 #undef DEFAULT_SYSROOT
 
@@ -31,4 +28,7 @@
 /* The LLVM product name and version */
 #define BACKEND_PACKAGE_STRING PACKAGE_STRING
 
+/* Linker version detected at compile time. */
+#undef HOST_LINK_VERSION
+
 #endif