Index: cmake/modules/HandleLLVMOptions.cmake
===================================================================
--- cmake/modules/HandleLLVMOptions.cmake
+++ cmake/modules/HandleLLVMOptions.cmake
@@ -7,6 +7,11 @@
 include(CheckCCompilerFlag)
 include(CheckCXXCompilerFlag)
 
+# uppercase_CMAKE_BUILD_TYPE is used in this module but is defined in
+# llvm/CMakeLists.txt. In order to allow for portible use of this module we
+# redefine it.
+string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
+
 if(NOT LLVM_FORCE_USE_OLD_TOOLCHAIN)
   if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
     if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.7)