diff --git a/compiler-rt/CMakeLists.txt b/compiler-rt/CMakeLists.txt
--- a/compiler-rt/CMakeLists.txt
+++ b/compiler-rt/CMakeLists.txt
@@ -12,12 +12,19 @@
   set_property(GLOBAL PROPERTY USE_FOLDERS ON)
 endif()
 
+# Has to be copied between projects because this is how we bootstrap these
+# shared modules.
+if(NOT DEFINED COMMON_CMAKE_UTILS)
+  set(COMMON_CMAKE_UTILS CACHE PATH "${CMAKE_CURRENT_SOURCE_DIR}/../cmake"
+    "CMake utilities shared between projects but not installed")
+endif()
+
 # Add path for custom compiler-rt modules.
 list(INSERT CMAKE_MODULE_PATH 0
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake"
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake/Modules"
-  "${CMAKE_CURRENT_SOURCE_DIR}/../cmake"
-  "${CMAKE_CURRENT_SOURCE_DIR}/../cmake/Modules"
+  "${COMMON_CMAKE_UTILS}"
+  "${COMMON_CMAKE_UTILS}/Modules"
   )
 
 if(CMAKE_CONFIGURATION_TYPES)
diff --git a/compiler-rt/lib/builtins/CMakeLists.txt b/compiler-rt/lib/builtins/CMakeLists.txt
--- a/compiler-rt/lib/builtins/CMakeLists.txt
+++ b/compiler-rt/lib/builtins/CMakeLists.txt
@@ -9,11 +9,22 @@
   project(CompilerRTBuiltins C ASM)
   set(COMPILER_RT_STANDALONE_BUILD TRUE)
   set(COMPILER_RT_BUILTINS_STANDALONE_BUILD TRUE)
+
+  set(COMPILER_RT_SOURCE_DIR}"${CMAKE_CURRENT_SOURCE_DIR}/../..")
+
+  # Has to be copied between projects because this is how we bootstrap these
+  # shared modules.
+  set(COMMON_CMAKE_UTILS CACHE PATH "${COMPILER_RT_SOURCE_DIR}/../cmake"
+    "CMake utilities shared between projects but not installed")
+
+  # Add path for custom modules
   list(INSERT CMAKE_MODULE_PATH 0
-    "${CMAKE_SOURCE_DIR}/../../cmake"
-    "${CMAKE_SOURCE_DIR}/../../cmake/Modules"
-    "${CMAKE_SOURCE_DIR}/../../../cmake"
-    "${CMAKE_SOURCE_DIR}/../../../cmake/Modules")
+    "${COMPILER_RT_SOURCE_DIR}/cmake"
+    "${COMPILER_RT_SOURCE_DIR}/cmake/Modules"
+    "${COMMON_CMAKE_UTILS}/cmake"
+    "${COMMON_CMAKE_UTILS}/cmake/Modules"
+	)
+
   include(base-config-ix)
   include(CompilerRTUtils)
 
diff --git a/flang/CMakeLists.txt b/flang/CMakeLists.txt
--- a/flang/CMakeLists.txt
+++ b/flang/CMakeLists.txt
@@ -227,10 +227,17 @@
   ${FLANG_BINARY_DIR}/include
   ${FLANG_SOURCE_DIR}/include)
 
+# Has to be copied between projects because this is how we bootstrap these
+# shared modules.
+if(NOT DEFINED COMMON_CMAKE_UTILS)
+  set(COMMON_CMAKE_UTILS CACHE PATH "${FLANG_SOURCE_DIR}/../cmake"
+    "CMake utilities shared between projects but not installed")
+endif()
+
 # Add Flang-centric modules to cmake path.
 list(INSERT CMAKE_MODULE_PATH 0
   "${FLANG_SOURCE_DIR}/cmake/modules"
-  "${FLANG_SOURCE_DIR}/../cmake/Modules"
+  "${COMMON_CMAKE_UTILS}/Modules"
   )
 include(AddFlang)
 
diff --git a/libcxx/CMakeLists.txt b/libcxx/CMakeLists.txt
--- a/libcxx/CMakeLists.txt
+++ b/libcxx/CMakeLists.txt
@@ -10,13 +10,19 @@
 #===============================================================================
 cmake_minimum_required(VERSION 3.13.4)
 
+# Has to be copied between projects because this is how we bootstrap these
+# shared modules.
+if(NOT DEFINED COMMON_CMAKE_UTILS)
+  set(COMMON_CMAKE_UTILS CACHE PATH "${CMAKE_CURRENT_SOURCE_DIR}/../cmake"
+    "CMake utilities shared between projects but not installed")
+endif()
+
 # Add path for custom modules
-set(CMAKE_MODULE_PATH
+list(INSERT CMAKE_MODULE_PATH 0
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake"
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake/Modules"
-  "${CMAKE_CURRENT_SOURCE_DIR}/../cmake"
-  "${CMAKE_CURRENT_SOURCE_DIR}/../cmake/Modules"
-  ${CMAKE_MODULE_PATH}
+  "${COMMON_CMAKE_UTILS}"
+  "${COMMON_CMAKE_UTILS}/Modules"
   )
 
 set(CMAKE_FOLDER "libc++")
diff --git a/libcxxabi/CMakeLists.txt b/libcxxabi/CMakeLists.txt
--- a/libcxxabi/CMakeLists.txt
+++ b/libcxxabi/CMakeLists.txt
@@ -10,13 +10,19 @@
 
 cmake_minimum_required(VERSION 3.13.4)
 
+# Has to be copied between projects because this is how we bootstrap these
+# shared modules.
+if(NOT DEFINED COMMON_CMAKE_UTILS)
+  set(COMMON_CMAKE_UTILS CACHE PATH "${CMAKE_CURRENT_SOURCE_DIR}/../cmake"
+    "CMake utilities shared between projects but not installed")
+endif()
+
 # Add path for custom modules
-set(CMAKE_MODULE_PATH
+list(INSERT CMAKE_MODULE_PATH 0
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake"
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake/Modules"
-  "${CMAKE_CURRENT_SOURCE_DIR}/../cmake"
-  "${CMAKE_CURRENT_SOURCE_DIR}/../cmake/Modules"
-  ${CMAKE_MODULE_PATH}
+  "${COMMON_CMAKE_UTILS}/cmake"
+  "${COMMON_CMAKE_UTILS}/cmake/Modules"
   )
 
 set(CMAKE_FOLDER "libc++")
diff --git a/libunwind/CMakeLists.txt b/libunwind/CMakeLists.txt
--- a/libunwind/CMakeLists.txt
+++ b/libunwind/CMakeLists.txt
@@ -8,13 +8,19 @@
 
 cmake_minimum_required(VERSION 3.13.4)
 
+# Has to be copied between projects because this is how we bootstrap these
+# shared modules.
+if(NOT DEFINED COMMON_CMAKE_UTILS)
+  set(COMMON_CMAKE_UTILS CACHE PATH "${CMAKE_CURRENT_SOURCE_DIR}/../cmake"
+    "CMake utilities shared between projects but not installed")
+endif()
+
 # Add path for custom modules
-set(CMAKE_MODULE_PATH
+list(INSERT CMAKE_MODULE_PATH 0
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake"
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake/Modules"
-  "${CMAKE_CURRENT_SOURCE_DIR}/../cmake"
-  "${CMAKE_CURRENT_SOURCE_DIR}/../cmake/Modules"
-  ${CMAKE_MODULE_PATH}
+  "${COMMON_CMAKE_UTILS}"
+  "${COMMON_CMAKE_UTILS}/Modules"
   )
 
 set(LIBUNWIND_SOURCE_DIR  ${CMAKE_CURRENT_SOURCE_DIR})
diff --git a/lld/CMakeLists.txt b/lld/CMakeLists.txt
--- a/lld/CMakeLists.txt
+++ b/lld/CMakeLists.txt
@@ -153,10 +153,17 @@
 "`CMakeFiles'. Please delete them.")
 endif()
 
+# Has to be copied between projects because this is how we bootstrap these
+# shared modules.
+if(NOT DEFINED COMMON_CMAKE_UTILS)
+  set(COMMON_CMAKE_UTILS CACHE PATH "${LLD_SOURCE_DIR}/../cmake"
+    "CMake utilities shared between projects but not installed")
+endif()
+
 # Add path for custom modules.
 list(INSERT CMAKE_MODULE_PATH 0
   "${LLD_SOURCE_DIR}/cmake/modules"
-  "${LLD_SOURCE_DIR}/../cmake/Modules"
+  "${COMMON_CMAKE_UTILS}/Modules"
   )
 
 include(AddLLD)
diff --git a/runtimes/CMakeLists.txt b/runtimes/CMakeLists.txt
--- a/runtimes/CMakeLists.txt
+++ b/runtimes/CMakeLists.txt
@@ -28,12 +28,19 @@
 find_package(LLVM PATHS "${LLVM_BINARY_DIR}" NO_DEFAULT_PATH NO_CMAKE_FIND_ROOT_PATH)
 find_package(Clang PATHS "${LLVM_BINARY_DIR}" NO_DEFAULT_PATH NO_CMAKE_FIND_ROOT_PATH)
 
+# Has to be copied between projects because this is how we bootstrap these
+# shared modules.
+if(NOT DEFINED COMMON_CMAKE_UTILS)
+  set(COMMON_CMAKE_UTILS CACHE PATH "${CMAKE_CURRENT_SOURCE_DIR}/../cmake"
+    "CMake utilities shared between projects but not installed")
+endif()
+
 # Add path for custom and the LLVM build's modules to the CMake module path.
 list(INSERT CMAKE_MODULE_PATH 0
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake"
   "${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules"
-  "${CMAKE_CURRENT_SOURCE_DIR}/../cmake"
-  "${CMAKE_CURRENT_SOURCE_DIR}/../cmake/Modules"
+  "${COMMON_CMAKE_UTILS}"
+  "${COMMON_CMAKE_UTILS}/Modules"
   "${CMAKE_CURRENT_SOURCE_DIR}/../llvm/cmake"
   "${CMAKE_CURRENT_SOURCE_DIR}/../llvm/cmake/modules"
 )