From 6387a7b3ae58096a027a08f1e49ca9d149a808dc Mon Sep 17 00:00:00 2001
From: Dave Lee <davelee.com@gmail.com>
Date: Mon, 19 Oct 2020 16:14:00 -0700
Subject: [PATCH] [build] Use llvm matching value for CMake policy CMP0077

---
 CMakeLists.txt | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index ecdbbca953913..99937910af2bc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -17,6 +17,11 @@ if(POLICY CMP0076)
   cmake_policy(SET CMP0076 NEW)
 endif()
 
+# Don't clobber existing variable values when evaluating `option()` declarations.
+if(POLICY CMP0077)
+  cmake_policy(SET CMP0077 NEW)
+endif()
+
 # Add path for custom CMake modules.
 list(APPEND CMAKE_MODULE_PATH
     "${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules")