Add a warning flag (-Wundef)

diff --git a/aclocal.m4 b/aclocal.m4
index 61a358a16927135cd3ad616db84e7ea488587b5a..94552b10868621f2f4eb47a5a43e601068989564 100644 (file)
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -761,6 +761,7 @@ AC_DEFUN(AC_LBL_DEVEL,
                    AC_LBL_CHECK_COMPILER_OPT($1, -Wshadow)
                    AC_LBL_CHECK_COMPILER_OPT($1, -Wsign-compare)
                    AC_LBL_CHECK_COMPILER_OPT($1, -Wstrict-prototypes)
+                   AC_LBL_CHECK_COMPILER_OPT($1, -Wundef)
                    AC_LBL_CHECK_COMPILER_OPT($1, -Wunreachable-code-return)
                    AC_LBL_CHECK_COMPILER_OPT($1, -Wunused-but-set-parameter)
                    AC_LBL_CHECK_COMPILER_OPT($1, -Wunused-but-set-variable)