Add the correct glue for selecting warning flags

configure.ac

@@ -78,6 +78,10 @@ AS_IF([test x"$REMCTLD" != x],
     [AC_DEFINE_UNQUOTED([PATH_REMCTLD], ["$REMCTLD"],
         [Define to the full path to remctld to run remctl tests.])])
 
+dnl Enable appropriate warnings.
+AM_CONDITIONAL([WARNINGS_GCC], [test x"$GCC" = xyes && test x"$CLANG" != xyes])
+AM_CONDITIONAL([WARNINGS_CLANG], [test x"$CLANG" = xyes])
+
 dnl Output section.
 AC_CONFIG_HEADER([config.h])
 AC_CONFIG_FILES([Makefile])