1# m4.m4 serial 2 2dnl Copyright (C) 2000, 2006 Free Software Foundation, Inc. 3dnl This file is free software; the Free Software Foundation 4dnl gives unlimited permission to copy and/or distribute it, 5dnl with or without modifications, as long as this notice is preserved. 6 7# AC_PROG_GNU_M4 8# -------------- 9# Check for GNU m4, at least 1.3 (supports frozen files). 10# Also, check whether --error-output (through 1.4.x) or --debugfile (2.0) 11# is supported, and AC_SUBST M4_DEBUGFILE accordingly. 12AC_DEFUN([AC_PROG_GNU_M4], 13[AC_PATH_PROGS([M4], [gm4 gnum4 m4], [m4]) 14AC_CACHE_CHECK([whether m4 supports frozen files], [ac_cv_prog_gnu_m4], 15[ac_cv_prog_gnu_m4=no 16if test x"$M4" != x; then 17 case `$M4 --help < /dev/null 2>&1` in 18 *reload-state*) ac_cv_prog_gnu_m4=yes ;; 19 esac 20fi]) 21if test $ac_cv_prog_gnu_m4 = yes ; then 22 AC_CACHE_CHECK([how m4 supports trace files], [ac_cv_prog_gnu_m4_debugfile], 23 [case `$M4 --help < /dev/null 2>&1` in 24 *debugfile*) ac_cv_prog_gnu_m4_debugfile=--debugfile ;; 25 *) ac_cv_prog_gnu_m4_debugfile=--error-output ;; 26 esac]) 27 AC_SUBST([M4_DEBUGFILE], $ac_cv_prog_gnu_m4_debugfile) 28fi 29]) 30