[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

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9b7322e279be53f76fba0094e7ae8a4fc110e2ca..53e5f33246aac63e0ff2dbf5e1769750dd75bb61 100644 (file)
--- 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()