# m4.m4 serial 2dnl Copyright (C) 2000, 2006 Free Software Foundation, Inc.dnl This file is free software; the Free Software Foundationdnl gives unlimited permission to copy and/or distribute it,dnl with or without modifications, as long as this notice is preserved.# AC_PROG_GNU_M4# --------------# Check for GNU m4, at least 1.3 (supports frozen files).# Also, check whether --error-output (through 1.4.x) or --debugfile (2.0)# is supported, and AC_SUBST M4_DEBUGFILE accordingly.AC_DEFUN([AC_PROG_GNU_M4],[AC_PATH_PROGS([M4], [gm4 gnum4 m4], [m4])AC_CACHE_CHECK([whether m4 supports frozen files], [ac_cv_prog_gnu_m4],[ac_cv_prog_gnu_m4=noif test x"$M4" != x; thencase `$M4 --help < /dev/null 2>&1` in*reload-state*) ac_cv_prog_gnu_m4=yes ;;esacfi])if test $ac_cv_prog_gnu_m4 = yes ; thenAC_CACHE_CHECK([how m4 supports trace files], [ac_cv_prog_gnu_m4_debugfile],[case `$M4 --help < /dev/null 2>&1` in*debugfile*) ac_cv_prog_gnu_m4_debugfile=--debugfile ;;*) ac_cv_prog_gnu_m4_debugfile=--error-output ;;esac])AC_SUBST([M4_DEBUGFILE], $ac_cv_prog_gnu_m4_debugfile)fi])