AC_ARG_WITH([system-llvm], [AC_HELP_STRING([--with-system-llvm],
 [use system llvm instead of built-in, uses full path to llvm-config
 @<:@default=/usr/local or /usr if not found in /usr/local@:>@])],

 [case "$withval" in
   yes)
     system_llvm="default"
     ;;
   no)
     system_llvm="built-in"
     ;;
   *)
     system_llvm=$withval
  esac
 ], [system_llvm="built-in"])
 

 AC_ARG_WITH([llvm-linking], [AC_HELP_STRING([--with-llvm-linking],
 [specifies method to linking llvm @<:@static|dynamic@:>@, only valid with --with-system-llvm])],
 [
 if test "x$system_llvm" = "xbuilt-in"; then
    AC_MSG_ERROR([Failed to configure LLVM, and LLVM linking was specified without specifying system-llvm])  
 else
 case "$withval" in
   static)
     llvm_linking="static"
     ;;
   dynamic)
     llvm_linking="dynamic"
     ;;
   *)
     AC_MSG_ERROR([Invalid argument to --with-llvm-linking])
 esac
 fi
 ], [
 if test "x$system_llvm" = "xbuilt-in"; then
    llvm_linking=""
 else
    llvm_linking="auto"
 fi
 ])
 

 AC_ARG_ENABLE([llvm],AC_HELP_STRING([--enable-llvm],

 [enable 'llvm' JIT/verifier support @<:@default=auto@:>@]),

 [enable_llvm=$enableval],
 [
 if test "x$system_llvm" != "xbuilt-in"; then
     enable_llvm="yes"
 else
     enable_llvm="auto"
 fi
 ])

 
 if test "$enable_llvm" != "no"; then
     dnl Try to configure subdir, optionally
     AC_CONFIG_SUBDIRS_OPTIONAL([libclamav/c++])

 else
     system_llvm="none"

     llvm_linking=""

 fi