Index: llvm/trunk/CMakeLists.txt
===================================================================
--- llvm/trunk/CMakeLists.txt
+++ llvm/trunk/CMakeLists.txt
@@ -49,61 +49,6 @@
   set(CMAKE_BUILD_TYPE "Debug" CACHE STRING "Build type (default Debug)" FORCE)
 endif()
 
-# This should only apply if you are both on an Apple host, and targeting Apple.
-if(CMAKE_HOST_APPLE AND APPLE)
-  # if CMAKE_LIBTOOL is not set, try and find it with xcrun or find_program
-  if(NOT CMAKE_LIBTOOL)
-    if(NOT CMAKE_XCRUN)
-      find_program(CMAKE_XCRUN NAMES xcrun)
-    endif()
-    if(CMAKE_XCRUN)
-      execute_process(COMMAND ${CMAKE_XCRUN} -find libtool
-        OUTPUT_VARIABLE CMAKE_LIBTOOL
-        OUTPUT_STRIP_TRAILING_WHITESPACE)
-    endif()
-
-    if(NOT CMAKE_LIBTOOL OR NOT EXISTS CMAKE_LIBTOOL)
-      find_program(CMAKE_LIBTOOL NAMES libtool)
-    endif()
-  endif()
-
-  get_property(languages GLOBAL PROPERTY ENABLED_LANGUAGES)
-  if(CMAKE_LIBTOOL)
-    set(CMAKE_LIBTOOL ${CMAKE_LIBTOOL} CACHE PATH "libtool executable")
-    message(STATUS "Found libtool - ${CMAKE_LIBTOOL}")
-
-    execute_process(COMMAND ${CMAKE_LIBTOOL} -V
-      OUTPUT_VARIABLE LIBTOOL_V_OUTPUT
-      OUTPUT_STRIP_TRAILING_WHITESPACE)
-    if("${LIBTOOL_V_OUTPUT}" MATCHES ".*cctools-([0-9.]+).*")
-      string(REGEX REPLACE ".*cctools-([0-9.]+).*" "\\1" LIBTOOL_VERSION
-        ${LIBTOOL_V_OUTPUT})
-      if(NOT LIBTOOL_VERSION VERSION_LESS "862")
-        set(LIBTOOL_NO_WARNING_FLAG "-no_warning_for_no_symbols")
-      endif()
-    endif()
-
-    foreach(lang ${languages})
-      set(CMAKE_${lang}_CREATE_STATIC_LIBRARY
-        "\"${CMAKE_LIBTOOL}\" -static ${LIBTOOL_NO_WARNING_FLAG} -o <TARGET> \
-        <LINK_FLAGS> <OBJECTS> ")
-    endforeach()
-  endif()
-
-  # If DYLD_LIBRARY_PATH is set we need to set it on archiver commands
-  if(DYLD_LIBRARY_PATH)
-    set(dyld_envar "DYLD_LIBRARY_PATH=${DYLD_LIBRARY_PATH}")
-    foreach(lang ${languages})
-      foreach(cmd ${CMAKE_${lang}_CREATE_STATIC_LIBRARY})
-        list(APPEND CMAKE_${lang}_CREATE_STATIC_LIBRARY_NEW
-             "${dyld_envar} ${cmd}")
-      endforeach()
-      set(CMAKE_${lang}_CREATE_STATIC_LIBRARY
-        ${CMAKE_${lang}_CREATE_STATIC_LIBRARY_NEW})
-    endforeach()
-  endif()
-endif()
-
 # Side-by-side subprojects layout: automatically set the
 # LLVM_EXTERNAL_${project}_SOURCE_DIR using LLVM_ALL_PROJECTS
 # This allows an easy way of setting up a build directory for llvm and another
@@ -648,6 +593,11 @@
   set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -static")
 endif()
 
+# Use libtool instead of ar if you are both on an Apple host, and targeting Apple.
+if(CMAKE_HOST_APPLE AND APPLE)
+  include(UseLibtool)
+endif()
+
 # Override the default target with an environment variable named by LLVM_TARGET_TRIPLE_ENV.
 set(LLVM_TARGET_TRIPLE_ENV CACHE STRING "The name of environment variable to override default target. Disabled by blank.")
 mark_as_advanced(LLVM_TARGET_TRIPLE_ENV)
Index: llvm/trunk/cmake/modules/UseLibtool.cmake
===================================================================
--- llvm/trunk/cmake/modules/UseLibtool.cmake
+++ llvm/trunk/cmake/modules/UseLibtool.cmake
@@ -0,0 +1,50 @@
+# if CMAKE_LIBTOOL is not set, try and find it with xcrun or find_program
+if(NOT CMAKE_LIBTOOL)
+  if(NOT CMAKE_XCRUN)
+    find_program(CMAKE_XCRUN NAMES xcrun)
+  endif()
+  if(CMAKE_XCRUN)
+    execute_process(COMMAND ${CMAKE_XCRUN} -find libtool
+      OUTPUT_VARIABLE CMAKE_LIBTOOL
+      OUTPUT_STRIP_TRAILING_WHITESPACE)
+  endif()
+
+  if(NOT CMAKE_LIBTOOL OR NOT EXISTS CMAKE_LIBTOOL)
+    find_program(CMAKE_LIBTOOL NAMES libtool)
+  endif()
+endif()
+
+get_property(languages GLOBAL PROPERTY ENABLED_LANGUAGES)
+if(CMAKE_LIBTOOL)
+  set(CMAKE_LIBTOOL ${CMAKE_LIBTOOL} CACHE PATH "libtool executable")
+  message(STATUS "Found libtool - ${CMAKE_LIBTOOL}")
+
+  execute_process(COMMAND ${CMAKE_LIBTOOL} -V
+    OUTPUT_VARIABLE LIBTOOL_V_OUTPUT
+    OUTPUT_STRIP_TRAILING_WHITESPACE)
+  if("${LIBTOOL_V_OUTPUT}" MATCHES ".*cctools-([0-9.]+).*")
+    string(REGEX REPLACE ".*cctools-([0-9.]+).*" "\\1" LIBTOOL_VERSION
+      ${LIBTOOL_V_OUTPUT})
+    if(NOT LIBTOOL_VERSION VERSION_LESS "862")
+      set(LIBTOOL_NO_WARNING_FLAG "-no_warning_for_no_symbols")
+    endif()
+  endif()
+
+  foreach(lang ${languages})
+    set(CMAKE_${lang}_CREATE_STATIC_LIBRARY
+      "\"${CMAKE_LIBTOOL}\" -static ${LIBTOOL_NO_WARNING_FLAG} -o <TARGET> <LINK_FLAGS> <OBJECTS>")
+  endforeach()
+endif()
+
+# If DYLD_LIBRARY_PATH is set we need to set it on archiver commands
+if(DYLD_LIBRARY_PATH)
+  set(dyld_envar "DYLD_LIBRARY_PATH=${DYLD_LIBRARY_PATH}")
+  foreach(lang ${languages})
+    foreach(cmd ${CMAKE_${lang}_CREATE_STATIC_LIBRARY})
+      list(APPEND CMAKE_${lang}_CREATE_STATIC_LIBRARY_NEW
+           "${dyld_envar} ${cmd}")
+    endforeach()
+    set(CMAKE_${lang}_CREATE_STATIC_LIBRARY
+      ${CMAKE_${lang}_CREATE_STATIC_LIBRARY_NEW})
+  endforeach()
+endif()
Index: llvm/trunk/runtimes/CMakeLists.txt
===================================================================
--- llvm/trunk/runtimes/CMakeLists.txt
+++ llvm/trunk/runtimes/CMakeLists.txt
@@ -117,6 +117,11 @@
   # Remove the -nostdlib++ option we've added earlier.
   string(REPLACE "-nostdlib++" "" CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")
 
+  # Use libtool instead of ar if you are both on an Apple host, and targeting Apple.
+  if(CMAKE_HOST_APPLE AND APPLE)
+    include(UseLibtool)
+  endif()
+
   # This can be used to detect whether we're in the runtimes build.
   set(RUNTIMES_BUILD ON)