[CMake] Introduce LLVM_EXTERNAL_COMPILER_RT_SOURCE_DIR.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166552 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/projects/CMakeLists.txt b/projects/CMakeLists.txt
index a9d2af6ad215b761c04a9919d05ff2d0dce0263a..36751cd31dac930297118a9bf9c971338fe6cba7 100644 (file)
--- a/projects/CMakeLists.txt
+++ b/projects/CMakeLists.txt
@@ -14,8 +14,6 @@ endforeach(entry)
 # Also add in the compiler-rt tree if present and we have a sufficiently
 # recent version of CMake.
 if(${CMAKE_VERSION} VERSION_GREATER 2.8.7 AND
-   ${LLVM_BUILD_RUNTIME} AND
-   IS_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/compiler-rt AND
-   EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/compiler-rt/CMakeLists.txt)
-  add_subdirectory(compiler-rt)
+   ${LLVM_BUILD_RUNTIME})
+  add_llvm_external_project(compiler-rt)
 endif()