+build_warnings="-W -Wall -Wstrict-prototypes -Wmissing-prototypes"
+
+AC_ARG_ENABLE(error-on-warning,
+ [ --enable-error-on-warning treat compile warnings as errors],
+ [case "${enableval}" in
+ yes | y) ERROR_ON_WARNING="yes" ;;
+ no | n) ERROR_ON_WARNING="no" ;;
+ *) AC_MSG_ERROR(bad value ${enableval} for --enable-error-on-warning) ;;
+ esac])
+
+# Enable -Werror by default, suppressing it only for --disable-error-on-warning
+# or --disable-build-warnings.
+if test "${ERROR_ON_WARNING}" != no
+then
+ build_warnings="$build_warnings -Werror"
+fi
+
+AC_ARG_ENABLE(build-warnings,
+[ --enable-build-warnings Enable build-time compiler warnings if gcc is used],
+[case "${enableval}" in
+ yes) ;;
+ no) build_warnings="-w";;
+ ,*) t=`echo "${enableval}" | sed -e "s/,/ /g"`
+ build_warnings="${build_warnings} ${t}";;
+ *,) t=`echo "${enableval}" | sed -e "s/,/ /g"`
+ build_warnings="${t} ${build_warnings}";;
+ *) build_warnings=`echo "${enableval}" | sed -e "s/,/ /g"`;;
+esac
+if test x"$silent" != x"yes" && test x"$build_warnings" != x""; then
+ echo "Setting warning flags = $build_warnings" 6>&1
+fi])dnl
+WARN_CFLAGS=""
+if test "x${build_warnings}" != x -a "x$GCC" = xyes ; then
+ WARN_CFLAGS="${build_warnings}"
+fi
+AC_SUBST(WARN_CFLAGS)
+