diff --git a/compiler-rt/cmake/Modules/AddCompilerRT.cmake b/compiler-rt/cmake/Modules/AddCompilerRT.cmake
--- a/compiler-rt/cmake/Modules/AddCompilerRT.cmake
+++ b/compiler-rt/cmake/Modules/AddCompilerRT.cmake
@@ -697,6 +697,7 @@
   endif()
 
   if(APPLE)
+    string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
     if(CMAKE_CXX_FLAGS MATCHES "-flto"
       OR CMAKE_CXX_FLAGS_${uppercase_CMAKE_BUILD_TYPE} MATCHES "-flto")
 
diff --git a/libcxx/CMakeLists.txt b/libcxx/CMakeLists.txt
--- a/libcxx/CMakeLists.txt
+++ b/libcxx/CMakeLists.txt
@@ -472,8 +472,7 @@
   set(CMAKE_BUILD_TYPE "COVERAGE" CACHE STRING "" FORCE)
 endif()
 
-string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
-if (uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG")
+if (CMAKE_BUILD_TYPE STREQUAL "Debug")
   set(LIBCXX_DEBUG_BUILD ON)
 else()
   set(LIBCXX_DEBUG_BUILD OFF)
@@ -677,8 +676,8 @@
     append_flags_if_supported(SANITIZER_FLAGS "-fno-omit-frame-pointer")
     append_flags_if_supported(SANITIZER_FLAGS "-gline-tables-only")
 
-    if (NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" AND
-            NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "RELWITHDEBINFO")
+    if (NOT CMAKE_BUILD_TYPE STREQUAL "Debug" AND
+            NOT CMAKE_BUILD_TYPE STREQUAL "RelWithDebInfo")
       append_flags_if_supported(SANITIZER_FLAGS "-gline-tables-only")
     endif()
     if (USE_SANITIZER STREQUAL "Address")
diff --git a/libcxx/utils/google-benchmark/test/CMakeLists.txt b/libcxx/utils/google-benchmark/test/CMakeLists.txt
--- a/libcxx/utils/google-benchmark/test/CMakeLists.txt
+++ b/libcxx/utils/google-benchmark/test/CMakeLists.txt
@@ -5,8 +5,7 @@
 
 # NOTE: Some tests use `<cassert>` to perform the test. Therefore we must
 # strip -DNDEBUG from the default CMake flags in DEBUG mode.
-string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
-if( NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" )
+if( NOT CMAKE_BUILD_TYPE STREQUAL "Debug" )
   add_definitions( -UNDEBUG )
   add_definitions(-DTEST_BENCHMARK_LIBRARY_HAS_NO_ASSERTIONS)
   # Also remove /D NDEBUG to avoid MSVC warnings about conflicting defines.
diff --git a/libcxxabi/CMakeLists.txt b/libcxxabi/CMakeLists.txt
--- a/libcxxabi/CMakeLists.txt
+++ b/libcxxabi/CMakeLists.txt
@@ -322,7 +322,6 @@
 endif()
 
 # Assert
-string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
 if (LIBCXXABI_ENABLE_ASSERTIONS)
   # MSVC doesn't like _DEBUG on release builds. See PR 4379.
   if (NOT MSVC)
@@ -330,11 +329,11 @@
   endif()
   # On Release builds cmake automatically defines NDEBUG, so we
   # explicitly undefine it:
-  if (uppercase_CMAKE_BUILD_TYPE STREQUAL "RELEASE")
+  if (CMAKE_BUILD_TYPE STREQUAL "Release")
     list(APPEND LIBCXXABI_COMPILE_FLAGS -UNDEBUG)
   endif()
 else()
-  if (NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "RELEASE")
+  if (NOT CMAKE_BUILD_TYPE STREQUAL "Release")
     list(APPEND LIBCXXABI_COMPILE_FLAGS -DNDEBUG)
   endif()
 endif()
diff --git a/libunwind/CMakeLists.txt b/libunwind/CMakeLists.txt
--- a/libunwind/CMakeLists.txt
+++ b/libunwind/CMakeLists.txt
@@ -259,7 +259,6 @@
 endif()
 
 # Assert
-string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
 if (LIBUNWIND_ENABLE_ASSERTIONS)
   # MSVC doesn't like _DEBUG on release builds. See PR 4379.
   if (NOT MSVC)
@@ -268,11 +267,11 @@
 
   # On Release builds cmake automatically defines NDEBUG, so we
   # explicitly undefine it:
-  if (uppercase_CMAKE_BUILD_TYPE STREQUAL "RELEASE")
+  if (CMAKE_BUILD_TYPE STREQUAL "Release")
     add_compile_flags(-UNDEBUG)
   endif()
 else()
-  if (NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "RELEASE")
+  if (NOT CMAKE_BUILD_TYPE STREQUAL "Release")
     add_compile_flags(-DNDEBUG)
   endif()
 endif()
diff --git a/lldb/CMakeLists.txt b/lldb/CMakeLists.txt
--- a/lldb/CMakeLists.txt
+++ b/lldb/CMakeLists.txt
@@ -30,7 +30,7 @@
 include(AddLLDB)
 
 # Define the LLDB_CONFIGURATION_xxx matching the build type.
-if(uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" )
+if(CMAKE_BUILD_TYPE STREQUAL "Debug" )
   add_definitions(-DLLDB_CONFIGURATION_DEBUG)
 endif()
 
diff --git a/llvm/CMakeLists.txt b/llvm/CMakeLists.txt
--- a/llvm/CMakeLists.txt
+++ b/llvm/CMakeLists.txt
@@ -254,10 +254,8 @@
 Please delete them.")
 endif()
 
-string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
-
 if (CMAKE_BUILD_TYPE AND
-    NOT uppercase_CMAKE_BUILD_TYPE MATCHES "^(DEBUG|RELEASE|RELWITHDEBINFO|MINSIZEREL)$")
+    NOT CMAKE_BUILD_TYPE MATCHES "^(Debug|Release|RelWithDebInfo|MinSizeRel)$")
   message(FATAL_ERROR "Invalid value for CMAKE_BUILD_TYPE: ${CMAKE_BUILD_TYPE}")
 endif()
 
@@ -414,7 +412,7 @@
 
 option(LLVM_ENABLE_DUMP "Enable dump functions even when assertions are disabled" OFF)
 
-if( NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" )
+if( NOT CMAKE_BUILD_TYPE STREQUAL "Debug" )
   option(LLVM_ENABLE_ASSERTIONS "Enable assertions" OFF)
 else()
   option(LLVM_ENABLE_ASSERTIONS "Enable assertions" ON)
@@ -521,7 +519,7 @@
   if(LLVM_USE_SANITIZER)
     message(FATAL_ERROR "LLVM_INTEGRATED_CRT_ALLOC cannot be used along with LLVM_USE_SANITIZER!")
   endif()
-  if(CMAKE_BUILD_TYPE AND uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG")
+  if(CMAKE_BUILD_TYPE STREQUAL "Debug")
     message(FATAL_ERROR "The Debug target isn't supported along with LLVM_INTEGRATED_CRT_ALLOC!")
   endif()
 endif()
diff --git a/llvm/cmake/modules/AddLLVM.cmake b/llvm/cmake/modules/AddLLVM.cmake
--- a/llvm/cmake/modules/AddLLVM.cmake
+++ b/llvm/cmake/modules/AddLLVM.cmake
@@ -217,7 +217,7 @@
 function(add_link_opts target_name)
   # Don't use linker optimizations in debug builds since it slows down the
   # linker in a context where the optimizations are not important.
-  if (NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG")
+  if (NOT CMAKE_BUILD_TYPE STREQUAL "Debug")
 
     # Pass -O3 to the linker. This enabled different optimizations on different
     # linkers.
@@ -1968,6 +1968,7 @@
       set(output_path "-o=${output_name}")
     endif()
 
+    string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
     if(CMAKE_CXX_FLAGS MATCHES "-flto"
       OR CMAKE_CXX_FLAGS_${uppercase_CMAKE_BUILD_TYPE} MATCHES "-flto")
 
diff --git a/llvm/cmake/modules/AddOCaml.cmake b/llvm/cmake/modules/AddOCaml.cmake
--- a/llvm/cmake/modules/AddOCaml.cmake
+++ b/llvm/cmake/modules/AddOCaml.cmake
@@ -93,6 +93,7 @@
   endforeach()
   # include -D/-UNDEBUG to match dump function visibility
   # regex from HandleLLVMOptions.cmake
+  string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
   string(REGEX MATCH "(^| )[/-][UD] *NDEBUG($| )" flag_matches
          "${CMAKE_C_FLAGS_${uppercase_CMAKE_BUILD_TYPE}} ${CMAKE_C_FLAGS}")
   set(c_flags "${c_flags} ${flag_matches}")
diff --git a/llvm/cmake/modules/HandleLLVMOptions.cmake b/llvm/cmake/modules/HandleLLVMOptions.cmake
--- a/llvm/cmake/modules/HandleLLVMOptions.cmake
+++ b/llvm/cmake/modules/HandleLLVMOptions.cmake
@@ -2,10 +2,6 @@
 # options and executing the appropriate CMake commands to realize the users'
 # selections.
 
-# This is commonly needed so make sure it's defined before we include anything
-# else.
-string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
-
 include(CheckCompilerVersion)
 include(HandleLLVMStdlib)
 include(CheckCCompilerFlag)
@@ -58,7 +54,7 @@
   endif()
   # On non-Debug builds cmake automatically defines NDEBUG, so we
   # explicitly undefine it:
-  if( NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" )
+  if( NOT CMAKE_BUILD_TYPE STREQUAL "Debug" )
     # NOTE: use `add_compile_options` rather than `add_definitions` since
     # `add_definitions` does not support generator expressions.
     add_compile_options($<$<OR:$<COMPILE_LANGUAGE:C>,$<COMPILE_LANGUAGE:CXX>>:-UNDEBUG>)
@@ -298,7 +294,7 @@
   endif()
   # GCC for MIPS can miscompile LLVM due to PR37701.
   if(CMAKE_COMPILER_IS_GNUCXX AND LLVM_NATIVE_ARCH STREQUAL "Mips" AND
-         NOT Uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG")
+         NOT CMAKE_BUILD_TYPE STREQUAL "Debug")
     add_flag_or_print_warning("-fno-shrink-wrap" FNO_SHRINK_WRAP)
   endif()
   # gcc with -O3 -fPIC generates TLS sequences that violate the spec on
@@ -448,7 +444,7 @@
   # (/Ob1 vs /Ob2 or -O2 vs -O3). LLVM provides this flag so that users can get
   # PDBs without changing codegen.
   option(LLVM_ENABLE_PDB OFF)
-  if (LLVM_ENABLE_PDB AND uppercase_CMAKE_BUILD_TYPE STREQUAL "RELEASE")
+  if (LLVM_ENABLE_PDB AND CMAKE_BUILD_TYPE STREQUAL "Release")
     append("/Zi" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
     # /DEBUG disables linker GC and ICF, but we want those in Release mode.
     append("/DEBUG /OPT:REF /OPT:ICF"
@@ -525,8 +521,8 @@
     set(module_flags "${module_flags} -Xclang -fmodules-local-submodule-visibility")
   endif()
   if (LLVM_ENABLE_MODULE_DEBUGGING AND
-      ((uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG") OR
-       (uppercase_CMAKE_BUILD_TYPE STREQUAL "RELWITHDEBINFO")))
+      ((CMAKE_BUILD_TYPE STREQUAL "Debug") OR
+       (CMAKE_BUILD_TYPE STREQUAL "RelWithDebInfo")))
     set(module_flags "${module_flags} -gmodules")
   endif()
   set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${module_flags}")
@@ -742,12 +738,12 @@
     # Append -fno-omit-frame-pointer and turn on debug info to get better
     # stack traces.
     add_flag_if_supported("-fno-omit-frame-pointer" FNO_OMIT_FRAME_POINTER)
-    if (NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" AND
-        NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "RELWITHDEBINFO")
+    if (NOT CMAKE_BUILD_TYPE STREQUAL "Debug" AND
+        NOT CMAKE_BUILD_TYPE STREQUAL "RelWithDebInfo")
       add_flag_if_supported("-gline-tables-only" GLINE_TABLES_ONLY)
     endif()
     # Use -O1 even in debug mode, otherwise sanitizers slowdown is too large.
-    if (uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" AND LLVM_OPTIMIZE_SANITIZED_BUILDS)
+    if (CMAKE_BUILD_TYPE STREQUAL "Debug" AND LLVM_OPTIMIZE_SANITIZED_BUILDS)
       add_flag_if_supported("-O1" O1)
     endif()
   elseif (CLANG_CL)
@@ -822,8 +818,8 @@
 
 # Turn on -gsplit-dwarf if requested in debug builds.
 if (LLVM_USE_SPLIT_DWARF AND
-    ((uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG") OR
-     (uppercase_CMAKE_BUILD_TYPE STREQUAL "RELWITHDEBINFO")))
+    ((CMAKE_BUILD_TYPE STREQUAL "Debug") OR
+     (CMAKE_BUILD_TYPE STREQUAL "RelWithDebInfo")))
   # Limit to clang and gcc so far. Add compilers supporting this option.
   if (CMAKE_CXX_COMPILER_ID MATCHES "Clang" OR
       CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
@@ -858,7 +854,7 @@
 # flags instead if LLVM_NO_DEAD_STRIP is set.
 if(NOT CYGWIN AND NOT WIN32)
   if(NOT ${CMAKE_SYSTEM_NAME} MATCHES "Darwin" AND
-     NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG")
+     NOT CMAKE_BUILD_TYPE STREQUAL "Debug")
     check_c_compiler_flag("-Werror -fno-function-sections" C_SUPPORTS_FNO_FUNCTION_SECTIONS)
     if (C_SUPPORTS_FNO_FUNCTION_SECTIONS)
       # Don't add -ffunction-sections if it can't be disabled with -fno-function-sections.
@@ -870,7 +866,7 @@
     add_flag_if_supported("-fdata-sections" FDATA_SECTIONS)
   endif()
 elseif(MSVC)
-  if( NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" )
+  if( NOT CMAKE_BUILD_TYPE STREQUAL "Debug" )
     append("/Gw" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
   endif()
 endif()
diff --git a/llvm/cmake/modules/TableGen.cmake b/llvm/cmake/modules/TableGen.cmake
--- a/llvm/cmake/modules/TableGen.cmake
+++ b/llvm/cmake/modules/TableGen.cmake
@@ -54,8 +54,8 @@
   endif()
   # Comments are only useful for Debug builds. Omit them if the backend
   # supports it.
-  if (NOT (uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" OR
-           uppercase_CMAKE_BUILD_TYPE STREQUAL "RELWITHDEBINFO"))
+  if (NOT (CMAKE_BUILD_TYPE STREQUAL "Debug" OR
+           CMAKE_BUILD_TYPE STREQUAL "RelWithDebInfo"))
     list(FIND ARGN "-gen-dag-isel" idx)
     if (NOT idx EQUAL -1)
       list(APPEND LLVM_TABLEGEN_FLAGS "-omit-comments")
diff --git a/llvm/lib/Support/CMakeLists.txt b/llvm/lib/Support/CMakeLists.txt
--- a/llvm/lib/Support/CMakeLists.txt
+++ b/llvm/lib/Support/CMakeLists.txt
@@ -50,6 +50,7 @@
 endif()
 
 # Override the C runtime allocator on Windows and embed it into LLVM tools & libraries
+string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
 if(LLVM_INTEGRATED_CRT_ALLOC)
   if (CMAKE_BUILD_TYPE AND NOT ${LLVM_USE_CRT_${uppercase_CMAKE_BUILD_TYPE}} MATCHES "^(MT|MTd)$")
     message(FATAL_ERROR "LLVM_INTEGRATED_CRT_ALLOC only works with /MT or /MTd. Use LLVM_USE_CRT_${uppercase_CMAKE_BUILD_TYPE} to set the appropriate option.")
diff --git a/llvm/utils/benchmark/test/CMakeLists.txt b/llvm/utils/benchmark/test/CMakeLists.txt
--- a/llvm/utils/benchmark/test/CMakeLists.txt
+++ b/llvm/utils/benchmark/test/CMakeLists.txt
@@ -5,8 +5,7 @@
 
 # NOTE: Some tests use `<cassert>` to perform the test. Therefore we must
 # strip -DNDEBUG from the default CMake flags in DEBUG mode.
-string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
-if( NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" )
+if( NOT CMAKE_BUILD_TYPE STREQUAL "Debug" )
   add_definitions( -UNDEBUG )
   add_definitions(-DTEST_BENCHMARK_LIBRARY_HAS_NO_ASSERTIONS)
   # Also remove /D NDEBUG to avoid MSVC warnings about conflicting defines.