3 # Check for GNU m4, at least 1.3 (supports frozen files).
4 AC_DEFUN([AC_PROG_GNU_M4],
5 [AC_PATH_PROGS(M4, gm4 gnum4 m4, m4)
6 AC_CACHE_CHECK(whether m4 supports frozen files, ac_cv_prog_gnu_m4,
8 if test x"$M4" != x; then
9 case `$M4 --help < /dev/null 2>&1` in
10 *reload-state*) ac_cv_prog_gnu_m4=yes ;;