diff --git a/cf/wflags.m4 b/cf/wflags.m4
new file mode 100644
index 000000000..f2f91a460
--- /dev/null
+++ b/cf/wflags.m4
@@ -0,0 +1,21 @@
+dnl $Id$
+dnl
+dnl set WFLAGS
+
+AC_DEFUN(AC_WFLAGS,[
+WFLAGS_NOUNUSED=""
+WFLAGS_NORETURNTYPE=""
+if test -z "$WFLAGS" -a "$GCC" = "yes"; then
+  # -Wno-return-type for broken X11 headers
+  # leave these out for now:
+  #   -Wcast-align doesn't work well on alpha osf/1
+  #   -Wmissing-prototypes -Wpointer-arith -Wbad-function-cast
+  #   -Wmissing-declarations -Wnested-externs
+  WFLAGS="ifelse($#, 0,-Wall -Wno-return-type, $1)"
+  WFLAGS_NOUNUSED="-Wno-unused"
+  WFLAGS_NORETURNTYPE="-Wno-return-type"
+fi
+AC_SUBST(WFLAGS)dnl
+AC_SUBST(WFLAGS_NOUNUSED)dnl
+AC_SUBST(WFLAGS_NORETURNTYPE)dnl
+])