From 2c7dd98b8a37e9a4adcaad76423f029ce7a09b77 Mon Sep 17 00:00:00 2001
From: Chris Bieneman <beanz@apple.com>
Date: Thu, 22 Sep 2016 00:18:12 +0000
Subject: [PATCH] [CMake] More robust handling for bootstrap variables

Checking defined isn't good enough we also need to handle defined to empty string.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@282125 91177308-0d34-0410-b5e6-96231b3b80d8
---
 CMakeLists.txt | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9b7322e279..53e5f33246 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -611,7 +611,11 @@ if (CLANG_ENABLE_BOOTSTRAP)
   # Populate the passthrough variables
   foreach(variableName ${CLANG_BOOTSTRAP_PASSTHROUGH} ${_BOOTSTRAP_DEFAULT_PASSTHROUGH})
     if(DEFINED ${variableName})
-      string(REPLACE ";" "\;" value ${${variableName}})
+      if("${${variableName}}" STREQUAL "")
+        set(value "")
+      else()
+        string(REPLACE ";" "\;" value ${${variableName}})
+      endif()
       list(APPEND PASSTHROUGH_VARIABLES
         -D${variableName}=${value})
     endif()
-- 
2.40.0