diff --git a/clang/CMakeLists.txt b/clang/CMakeLists.txt
--- a/clang/CMakeLists.txt
+++ b/clang/CMakeLists.txt
@@ -785,24 +785,16 @@
   endforeach()
 
   # Build arguments for native tool used in CMake.
-  set(build_configuration "$<CONFIG>")
   set(build_tool_args "${LLVM_EXTERNAL_PROJECT_BUILD_TOOL_ARGS}")
   if(NOT build_tool_args STREQUAL "")
     string(PREPEND build_tool_args "-- ")
     separate_arguments(build_tool_args UNIX_COMMAND "${build_tool_args}")
   endif()
 
-  ExternalProject_Add(${NEXT_CLANG_STAGE}
+  include(ClangBootstrap)
+  clang_Bootstrap_Add(${NEXT_CLANG_STAGE}
     DEPENDS clang-bootstrap-deps
-    PREFIX ${NEXT_CLANG_STAGE}
-    SOURCE_DIR ${CMAKE_SOURCE_DIR}
-    STAMP_DIR ${STAMP_DIR}
-    BINARY_DIR ${BINARY_DIR}
-    EXCLUDE_FROM_ALL 1
     CMAKE_ARGS
-                # We shouldn't need to set this here, but INSTALL_DIR doesn't
-                # seem to work, so instead I'm passing this through
-                -DCMAKE_INSTALL_PREFIX=${CMAKE_INSTALL_PREFIX}
                 ${PASSTHROUGH_VARIABLES}
                 ${CLANG_BOOTSTRAP_CMAKE_ARGS}
                  -DCLANG_STAGE=${NEXT_CLANG_STAGE}
@@ -814,16 +806,8 @@
                 ${${CLANG_STAGE}_RANLIB}
                 ${${CLANG_STAGE}_OBJCOPY}
                 ${${CLANG_STAGE}_STRIP}
-    BUILD_COMMAND ${CMAKE_COMMAND} --build ${BINARY_DIR}
-                                   --config ${build_configuration}
-                                   ${build_tool_args}
-    INSTALL_COMMAND ""
-    STEP_TARGETS configure build
-    USES_TERMINAL_CONFIGURE 1
-    USES_TERMINAL_BUILD 1
-    USES_TERMINAL_INSTALL 1
-    LIST_SEPARATOR |
-    )
+    BUILD_TOOL_ARGS ${build_tool_args}
+  )
 
   # exclude really-install from main target
   set_target_properties(${NEXT_CLANG_STAGE} PROPERTIES _EP_really-install_EXCLUDE_FROM_MAIN On)
@@ -904,37 +888,23 @@
   )
 
   # Build specified targets with instrumented Clang to collect the profile
-  set(STAMP_DIR ${CMAKE_CURRENT_BINARY_DIR}/bolt-instrumented-clang-stamps/)
-  set(BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/bolt-instrumented-clang-bins/)
-  set(build_configuration "$<CONFIG>")
-  include(ExternalProject)
-  ExternalProject_Add(bolt-instrumentation-profile
+  include(ClangBootstrap)
+  set(COMPILER_OPTIONS
+    -DCMAKE_C_COMPILER=${CLANG_INSTRUMENTED}
+    -DCMAKE_CXX_COMPILER=${CLANGXX_INSTRUMENTED}
+    -DCMAKE_ASM_COMPILER=${CLANG_INSTRUMENTED}
+    -DCMAKE_ASM_COMPILER_ID=Clang
+  )
+  clang_Bootstrap_Add(bolt-instrumentation-profile
     DEPENDS clang++-instrumented
-    PREFIX bolt-instrumentation-profile
-    SOURCE_DIR ${CMAKE_SOURCE_DIR}
-    STAMP_DIR ${STAMP_DIR}
-    BINARY_DIR ${BINARY_DIR}
-    EXCLUDE_FROM_ALL 1
     CMAKE_ARGS
                 ${CLANG_BOLT_INSTRUMENT_EXTRA_CMAKE_FLAGS}
-                # We shouldn't need to set this here, but INSTALL_DIR doesn't
-                # seem to work, so instead I'm passing this through
-                -DCMAKE_INSTALL_PREFIX=${CMAKE_INSTALL_PREFIX}
-                -DCMAKE_C_COMPILER=${CLANG_INSTRUMENTED}
-                -DCMAKE_CXX_COMPILER=${CLANGXX_INSTRUMENTED}
-                -DCMAKE_ASM_COMPILER=${CLANG_INSTRUMENTED}
-                -DCMAKE_ASM_COMPILER_ID=Clang
+                ${COMPILER_OPTIONS}
                 -DCMAKE_BUILD_TYPE=Release
                 -DLLVM_ENABLE_PROJECTS=${CLANG_BOLT_INSTRUMENT_PROJECTS}
                 -DLLVM_TARGETS_TO_BUILD=${LLVM_TARGETS_TO_BUILD}
-    BUILD_COMMAND ${CMAKE_COMMAND} --build ${BINARY_DIR}
-                                   --config ${build_configuration}
-                                   --target ${CLANG_BOLT_INSTRUMENT_TARGETS}
-    INSTALL_COMMAND ""
-    STEP_TARGETS configure build
-    USES_TERMINAL_CONFIGURE 1
-    USES_TERMINAL_BUILD 1
-    USES_TERMINAL_INSTALL 1
+    BUILD_TOOL_ARGS
+                    --target ${CLANG_BOLT_INSTRUMENT_TARGETS}
   )
 
   # Merge profiles into one using merge-fdata
diff --git a/clang/cmake/modules/ClangBootstrap.cmake b/clang/cmake/modules/ClangBootstrap.cmake
new file mode 100644
--- /dev/null
+++ b/clang/cmake/modules/ClangBootstrap.cmake
@@ -0,0 +1,41 @@
+include(ExternalProject)
+
+# clang_Bootstrap_Add(name ...
+#   DEPENDS targets...
+#     Targets that this project depends on
+#   CMAKE_ARGS arguments...
+#     Optional cmake arguments to pass when configuring the project
+#   BUILD_TOOL_ARGS arguments...
+#     Optional arguments to pass to the build tool
+macro(clang_Bootstrap_Add name)
+  cmake_parse_arguments(ARG "" "LINKER;AR;RANLIB;OBJCOPY;STRIP"
+    "DEPENDS;TABLEGEN;CMAKE_ARGS;BUILD_TOOL_ARGS"
+    ${ARGN})
+  set(STAMP_DIR ${CMAKE_CURRENT_BINARY_DIR}/${name}-stamps/)
+  set(BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/${name}-bins/)
+  # Build arguments for native tool used in CMake.
+  set(build_configuration "$<CONFIG>")
+
+  ExternalProject_Add(${name}
+    DEPENDS ${ARG_DEPENDS}
+    PREFIX ${name}
+    SOURCE_DIR ${CMAKE_SOURCE_DIR}
+    STAMP_DIR ${STAMP_DIR}
+    BINARY_DIR ${BINARY_DIR}
+    EXCLUDE_FROM_ALL 1
+    CMAKE_ARGS
+                # We shouldn't need to set this here, but INSTALL_DIR doesn't
+                # seem to work, so instead I'm passing this through
+                -DCMAKE_INSTALL_PREFIX=${CMAKE_INSTALL_PREFIX}
+                ${ARG_CMAKE_ARGS}
+    BUILD_COMMAND ${CMAKE_COMMAND} --build ${BINARY_DIR}
+                                   --config ${build_configuration}
+                                   ${ARG_BUILD_TOOL_ARGS}
+    INSTALL_COMMAND ""
+    STEP_TARGETS configure build
+    USES_TERMINAL_CONFIGURE 1
+    USES_TERMINAL_BUILD 1
+    USES_TERMINAL_INSTALL 1
+    LIST_SEPARATOR |
+  )
+endmacro()