[llvm] r343088 - [CMake] Avoid REVERSE on unset variable

[Sven van Haastregt via llvm-commits]

Author: svenvh
Date: Wed Sep 26 03:14:10 2018
New Revision: 343088

URL: http://llvm.org/viewvc/llvm-project?rev=343088&view=rev
Log:
[CMake] Avoid REVERSE on unset variable

If required_libs happens to remain unset, CMake would fail with:

  list sub-command REVERSE requires list to be present.

Fix by ensuring we do not attempt to reverse an unset variable.

Reported by Tu Vuong.

Differential Revision: https://reviews.llvm.org/D51799

Modified:
    llvm/trunk/cmake/modules/LLVM-Config.cmake

Modified: llvm/trunk/cmake/modules/LLVM-Config.cmake
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/cmake/modules/LLVM-Config.cmake?rev=343088&r1=343087&r2=343088&view=diff
==============================================================================
--- llvm/trunk/cmake/modules/LLVM-Config.cmake (original)
+++ llvm/trunk/cmake/modules/LLVM-Config.cmake Wed Sep 26 03:14:10 2018
@@ -302,7 +302,9 @@ function(llvm_expand_dependencies out_li
     expand_topologically(${lib} "${required_libs}" "${visited_libs}")
   endforeach()
 
-  list(REVERSE required_libs)
+  if(required_libs)
+    list(REVERSE required_libs)
+  endif()
   set(${out_libs} ${required_libs} PARENT_SCOPE)
 endfunction()