[compiler-rt] [compiler-rt] Don't redefine LLVM_COMMON_CMAKE_UTILS if it's defined (PR #66761)

[Xi Ruoyao via llvm-commits]

https://github.com/xry111 created https://github.com/llvm/llvm-project/pull/66761

If we are building compiler-rt inside llvm-x.y.z.src directory, we should not redefine LLVM_COMMON_CMAKE_UTILS.

>From ca68305e3c48cff7be8dbbe2809dfcf98a2d0604 Mon Sep 17 00:00:00 2001
From: Xi Ruoyao <xry111 at xry111.site>
Date: Tue, 19 Sep 2023 18:42:26 +0800
Subject: [PATCH] [compiler-rt] Don't redefine LLVM_COMMON_CMAKE_UTILS if it's
 defined

If we are building compiler-rt inside llvm-x.y.z.src directory, we
should not redefine LLVM_COMMON_CMAKE_UTILS.
---
 compiler-rt/CMakeLists.txt | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/compiler-rt/CMakeLists.txt b/compiler-rt/CMakeLists.txt
index cc3190bd7f761e2..6777c592ffd60af 100644
--- a/compiler-rt/CMakeLists.txt
+++ b/compiler-rt/CMakeLists.txt
@@ -5,7 +5,9 @@
 
 cmake_minimum_required(VERSION 3.20.0)
 
-set(LLVM_COMMON_CMAKE_UTILS "${CMAKE_CURRENT_SOURCE_DIR}/../cmake")
+if(NOT DEFINED LLVM_COMMON_CMAKE_UTILS)
+  set(LLVM_COMMON_CMAKE_UTILS ${CMAKE_CURRENT_SOURCE_DIR}/../cmake)
+endif()
 include(${LLVM_COMMON_CMAKE_UTILS}/Modules/CMakePolicy.cmake
   NO_POLICY_SCOPE)