cmake: allow to set a Lua library outside

Author: ligurio

CMakeLists.txt

@@ -51,6 +51,11 @@ elseif (USE_LUAJIT)
   include(BuildLuaJIT)
   build_luajit(${LUA_VERSION})
   set(IS_LUAJIT TRUE)
+elseif (LUA_INCLUDE_DIR AND LUA_LIBRARIES AND LUA_EXECUTABLE AND LUA_VERSION_STRING)
+  message(STATUS "Lua library passed outside:")
+  message(STATUS "LUA_INCLUDE_DIR: ${LUA_INCLUDE_DIR}")
+  message(STATUS "LUA_LIBRARIES: ${LUA_LIBRARIES}")
+  message(STATUS "LUA_EXECUTABLE: ${LUA_EXECUTABLE}")
 else ()
   message(FATAL_ERROR "No Lua is specified.")
 endif ()