configure.ac - m4 - Git at Google

 # Configure template for GNU m4.           -*-Autoconf-*-
 # Copyright (C) 1991-1994, 2000-2002, 2004-2014, 2017 Free Software
 # Foundation, Inc.
 #
 # This file is part of GNU M4.
 #
 # GNU M4 is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation, either version 3 of the License, or
 # (at your option) any later version.
 #
 # GNU M4 is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.

 dnl We depend on autotest's ./testsuite -C.
 AC_PREREQ([2.62])

 ## ------------------------ ##
 ## Autoconf initialization. ##
 ## ------------------------ ##
 m4_define([M4_VERSION],
           m4_esyscmd([build-aux/git-version-gen .tarball-version]))
 m4_bmatch(m4_defn([M4_VERSION]), [^[0-9]], [],
           [m4_define([M4_VERSION], [1.9a])])
 AC_INIT([GNU M4], m4_defn([M4_VERSION]), [bug-m4@gnu.org])

 AC_CONFIG_SRCDIR([src/m4.h])
 AC_CONFIG_AUX_DIR([build-aux])
 AC_CONFIG_MACRO_DIR([build-aux/m4])
 AC_CONFIG_LIBOBJ_DIR([m4/gnu])
 AC_CONFIG_TESTDIR([tests])
 AC_CONFIG_HEADERS([config.h])
 AC_CONFIG_FILES([tests/m4], [chmod +x tests/m4])


 ## -------------------------- ##
 ## M4 specific configuration. ##
 ## -------------------------- ##
 dnl Autoconf recommends that packages use lowercase for their package-specific
 dnl prefix for cache variables.  But in the case of m4, that collides with
 dnl the m4_ namespace provided by m4sugar, so we prefer M4_ as our
 dnl package-specific prefix.
 m4_pattern_forbid([^M4_[A-Z]])

 AC_DEFUN([M4_DEFAULT_PRELOAD], [])
 M4_default_preload="M4_DEFAULT_PRELOAD"


 ## ------------------------ ##
 ## Automake Initialization. ##
 ## ------------------------ ##
 AM_INIT_AUTOMAKE([1.11.6 subdir-objects dist-bzip2 dist-xz
 color-tests parallel-tests silent-rules]
 m4_if(m4_index(m4_defn([M4_VERSION]), [-]), [-1], [gnits], [gnu]))
 AM_SILENT_RULES([yes]) # make --enable-silent-rules the default.


 ## ------------------ ##
 ## C compiler checks. ##
 ## ------------------ ##
 AC_PROG_CC
 AC_DEFUN([gl_CXX_CHOICE_DEFAULT_NO])
 M4_EARLY

 # Maintainer note - comment this line out if you plan to rerun
 # GNULIB_POSIXCHECK testing to see if M4 should be using more modules.
 # Leave it uncommented for normal releases, for faster ./configure.
 gl_ASSERT_NO_GNULIB_POSIXCHECK

 AC_SYS_LARGEFILE
 AC_PROG_CPP
 AM_PROG_CC_C_O
 M4_CHECK_DEBUGGING


 ## --------------------------- ##
 ## C compiler characteristics. ##
 ## --------------------------- ##
 AC_TYPE_SIZE_T
 AC_CHECK_SIZEOF([long long int])

 AS_CASE([$host], [*-*-os2*], [OS2_LDFLAGS=-Zargs-resp])
 AC_SUBST([OS2_LDFLAGS])


 ## ----------------------- ##
 ## Libtool initialization. ##
 ## ----------------------- ##
 LT_PREREQ([2.2])
 LT_INIT([shared dlopen win32-dll])

 AC_ARG_ENABLE([gcc-warnings],
   [AS_HELP_STRING([--enable-gcc-warnings],
                   [turn on lots of GCC warnings (for developers)])],
   [case $enableval in
      yes|no) ;;
      *)      AC_MSG_ERROR([bad value $enableval for gcc-warnings option]) ;;
    esac
    gl_gcc_warnings=$enableval],
   [gl_gcc_warnings=no]
 )

 if test "$gl_gcc_warnings" = yes; then
   gl_WARN_ADD([-Werror], [WERROR_CFLAGS])
   AC_SUBST([WERROR_CFLAGS])

   # This, $nw, is the list of warnings we disable.
   nw=
   nw="$nw -Waggregate-return"       # K&R is anachronistic
   nw="$nw -Wtraditional-conversion" # K&R is anachronistic
   nw="$nw -Wundef"                  # K&R is anachronistic
   nw="$nw -Wlong-long"              # C90 is anachronistic
   nw="$nw -Wsystem-headers"         # Don't let system headers trigger warnings
   nw="$nw -Wpadded"                 # Our structs are not packed
   nw="$nw -Wformat-nonliteral"      # Needed in builtin.c
   nw="$nw -Wconversion"             # Too many warnings for now
   nw="$nw -Wsign-conversion"        # Too many warnings for now
   nw="$nw -Wcast-qual"              # Too many warnings for now
   nw="$nw -Wswitch-enum"            # Too many warnings for now
   # gcc 4.4.6 complains enum-compare is C++ only; gcc 4.7.0 implies it in -Wall
   nw="$nw -Wenum-compare"

   # Gnulib uses '#pragma GCC diagnostic push' to silence some
   # warnings, but older gcc doesn't support this.
   AC_CACHE_CHECK([whether pragma GCC diagnostic push works],
     [M4_cv_gcc_pragma_push_works], [
     save_CFLAGS=$CFLAGS
     CFLAGS='-Wunknown-pragmas -Werror'
     AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
       #pragma GCC diagnostic push
       #pragma GCC diagnostic pop
     ]])],
     [M4_cv_gcc_pragma_push_works=yes],
     [M4_cv_gcc_pragma_push_works=no])
     CFLAGS=$save_CFLAGS])
   if test $M4_cv_gcc_pragma_push_works = no; then
     nw="$nw -Wmissing-prototypes"
     nw="$nw -Wmissing-declarations"
     nw="$nw -Wunreachable-code"
   fi

   gl_MANYWARN_ALL_GCC([ws])
   gl_MANYWARN_COMPLEMENT([ws], [$ws], [$nw])
   for w in $ws; do
     gl_WARN_ADD([$w])
   done

   gl_WARN_ADD([-fdiagnostics-show-option])
   gl_WARN_ADD([-funit-at-a-time])

   AC_SUBST([WARN_CFLAGS])

   AH_VERBATIM([FORTIFY_SOURCE],
   [/* Enable compile-time and run-time bounds-checking, and some warnings,
       without upsetting newer glibc. */
    #if defined __OPTIMIZE__ && __OPTIMIZE__
    # define _FORTIFY_SOURCE 2
    #endif
   ])
 fi

 # Use gcc's -pipe option if available: for faster compilation.
 case "$CFLAGS" in
   *-pipe* ) ;;
         * ) _LT_COMPILER_OPTION([if $compiler supports -pipe],
                 [M4_cv_prog_compiler_pipe],
                 [-pipe -c conftest.$ac_ext], [],
                 [CFLAGS="$CFLAGS -pipe"])
               ;;
 esac


 ## ------------------------------- ##
 ## Dynamic Loader Characteristics. ##
 ## ------------------------------- ##

 LT_LIB_DLLOAD
 LT_SYS_SYMBOL_USCORE

 LT_SYS_MODULE_EXT

 if test yes = "$sys_symbol_underscore"; then
   libm4_shlibext=$libltdl_cv_shlibext

   AC_MSG_CHECKING([whether dlsym requires underscore prefixed symbols])
   AC_CACHE_VAL([libm4_cv_sys_dlsym_uscore], [dnl
     libname=conftmod # stay within 8.3 filename limits!
     cat >$libname.$ac_ext <<_M4_EOF
 [#line $LINENO "configure"
 #include "confdefs.h"
 /* When -fvisibility=hidden is used, assume the code has been annotated
    correspondingly for the symbols needed.  */
 #if defined __GNUC__ && (((__GNUC__ == 3) && (__GNUC_MINOR__ >= 3)) || (__GNUC__ > 3))
 int fnord () __attribute__((visibility("default")));
 #endif
 int fnord () { return 42; }]
 _M4_EOF

     # fn_module_cmds module_cmds
     # Execute tilde-delimited MODULE_CMDS with environment primed for
     # ${module_cmds} or ${archive_cmds} type content.
     fn_module_cmds ()
     {( # subshell avoids polluting parent global environment
         module_cmds_save_ifs=$IFS; IFS='~'
         for cmd in $1; do
           IFS=$module_cmds_save_ifs
           libobjs=$libname.$ac_objext; lib=$libname$libm4_shlibext
           rpath=/not-exists; soname=$libname$libm4_shlibext; output_objdir=.
           major=; versuffix=; verstring=; deplibs=
           ECHO=echo; wl=$lt_prog_compiler_wl; allow_undefined_flag=
           eval $cmd
         done
         IFS=$module_cmds_save_ifs
     )}

     # Compile a loadable module using libtool macro expansion results.
     $CC $pic_flag -c $libname.$ac_ext
     fn_module_cmds "${module_cmds:-$archive_cmds}"

     # Try to fetch fnord with dlsym().
     libm4_dlunknown=0; libm4_dlnouscore=1; libm4_dluscore=2
     cat >conftest.$ac_ext <<_M4_EOF
 [#line $LINENO "configure"
 #include "confdefs.h"
 #if HAVE_DLFCN_H
 #include <dlfcn.h>
 #endif
 #include <stdio.h>
 #ifndef RTLD_GLOBAL
 #  ifdef DL_GLOBAL
 #    define RTLD_GLOBAL DL_GLOBAL
 #  else
 #    define RTLD_GLOBAL 0
 #  endif
 #endif
 #ifndef RTLD_NOW
 #  ifdef DL_NOW
 #    define RTLD_NOW DL_NOW
 #  else
 #    define RTLD_NOW 0
 #  endif
 #endif
 int main () {
   void *handle = dlopen ("`pwd`/$libname$libm4_shlibext", RTLD_GLOBAL|RTLD_NOW);
   int status = $libm4_dlunknown;
   if (handle) {
     if (dlsym (handle, "fnord"))
       status = $libm4_dlnouscore;
     else {
       if (dlsym (handle, "_fnord"))
         status = $libm4_dluscore;
       else
 	puts (dlerror ());
     }
     dlclose (handle);
   } else
     puts (dlerror ());
   return status;
 }]
 _M4_EOF
     if AC_TRY_EVAL(ac_link) && test -s "conftest$ac_exeext" 2>/dev/null; then
       (./conftest; exit; ) >&AS_MESSAGE_LOG_FD 2>/dev/null
       libm4_status=$?
       case x$libm4_status in
         x$libm4_dlnouscore) libm4_cv_sys_dlsym_uscore=no ;;
 	x$libm4_dluscore) libm4_cv_sys_dlsym_uscore=yes ;;
 	x*) libm4_cv_sys_dlsym_uscore=unknown ;;
       esac
     fi
     rm -rf conftest* $libname*
   ])
   sys_dlsym_uscore=$libm4_cv_sys_dlsym_uscore
   AC_MSG_RESULT($sys_dlsym_uscore)
   if test yes = "$sys_dlsym_uscore"; then
     AC_DEFINE([DLSYM_USCORE], [1],
       [Define if dlsym() requires a leading underscore in symbol names.])
   fi
 fi

 AC_DEFINE_UNQUOTED([PATH_SEPARATOR], ['$PATH_SEPARATOR'],
 		   [Define this to system search path delimiter])


 ## ---------------- ##
 ## Gettext support. ##
 ## ---------------- ##
 AM_GNU_GETTEXT([external])
 AM_GNU_GETTEXT_NEED([need-formatstring-macros])
 AM_GNU_GETTEXT_VERSION([0.16])
 M4_GNU_GETTEXT


 ## --------------- ##
 ## Gnulib support. ##
 ## --------------- ##
 M4_INIT

 gl_VERSION_ETC

 # Gnulib doesn't always do things quite the way M4 would like...
 M4_ERROR
 M4_GETOPT
 M4_OBSTACK
 M4_REGEX
 M4_RENAME


 ## ------------------------- ##
 ## C headers required by M4. ##
 ## ------------------------- ##
 AC_CHECK_HEADERS_ONCE([limits.h])

 if test $ac_cv_header_stdbool_h = yes; then
   INCLUDE_STDBOOL_H='#include <stdbool.h>'
 else
   INCLUDE_STDBOOL_H='#include <gnu/stdbool.h>'
 fi
 AC_SUBST([INCLUDE_STDBOOL_H])


 ## --------------------------------- ##
 ## Library functions required by M4. ##
 ## --------------------------------- ##
 AC_CHECK_FUNCS_ONCE([calloc strerror])

 AM_WITH_DMALLOC

 M4_SYS_STACKOVF

 # This is for the modules
 AC_STRUCT_TM
 AC_FUNC_STRFTIME
 AC_CHECK_FUNCS_ONCE([getcwd gethostname mktime uname])


 ## ------------------ ##
 ## Configure options. ##
 ## ------------------ ##

 M4_LIB_GMP
 AM_CONDITIONAL([USE_GMP], [test "x$USE_GMP" = xyes])
 M4_SYSCMD


 ## -------- ##
 ## Outputs. ##
 ## -------- ##
 AC_CONFIG_FILES([
 Makefile
 doc/Makefile
 m4/gnu/Makefile
 m4/system.h:m4/system_.h
 tests/atlocal
 tests/gnu/Makefile
 ])

 AC_OUTPUT
	# Configure template for GNU m4. --Autoconf--
	# Copyright (C) 1991-1994, 2000-2002, 2004-2014, 2017 Free Software
	# Foundation, Inc.
	#
	# This file is part of GNU M4.
	#
	# GNU M4 is free software: you can redistribute it and/or modify
	# it under the terms of the GNU General Public License as published by
	# the Free Software Foundation, either version 3 of the License, or
	# (at your option) any later version.
	#
	# GNU M4 is distributed in the hope that it will be useful,
	# but WITHOUT ANY WARRANTY; without even the implied warranty of
	# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	# GNU General Public License for more details.
	#
	# You should have received a copy of the GNU General Public License
	# along with this program. If not, see <http://www.gnu.org/licenses/>.

	dnl We depend on autotest's ./testsuite -C.
	AC_PREREQ([2.62])

	## ------------------------ ##
	## Autoconf initialization. ##
	## ------------------------ ##
	m4_define([M4_VERSION],
	m4_esyscmd([build-aux/git-version-gen .tarball-version]))
	m4_bmatch(m4_defn([M4_VERSION]), [^[0-9]], [],
	[m4_define([M4_VERSION], [1.9a])])
	AC_INIT([GNU M4], m4_defn([M4_VERSION]), [bug-m4@gnu.org])

	AC_CONFIG_SRCDIR([src/m4.h])
	AC_CONFIG_AUX_DIR([build-aux])
	AC_CONFIG_MACRO_DIR([build-aux/m4])
	AC_CONFIG_LIBOBJ_DIR([m4/gnu])
	AC_CONFIG_TESTDIR([tests])
	AC_CONFIG_HEADERS([config.h])
	AC_CONFIG_FILES([tests/m4], [chmod +x tests/m4])


	## -------------------------- ##
	## M4 specific configuration. ##
	## -------------------------- ##
	dnl Autoconf recommends that packages use lowercase for their package-specific
	dnl prefix for cache variables. But in the case of m4, that collides with
	dnl the m4_ namespace provided by m4sugar, so we prefer M4_ as our
	dnl package-specific prefix.
	m4_pattern_forbid([^M4_[A-Z]])

	AC_DEFUN([M4_DEFAULT_PRELOAD], [])
	M4_default_preload="M4_DEFAULT_PRELOAD"


	## ------------------------ ##
	## Automake Initialization. ##
	## ------------------------ ##
	AM_INIT_AUTOMAKE([1.11.6 subdir-objects dist-bzip2 dist-xz
	color-tests parallel-tests silent-rules]
	m4_if(m4_index(m4_defn([M4_VERSION]), [-]), [-1], [gnits], [gnu]))
	AM_SILENT_RULES([yes]) # make --enable-silent-rules the default.


	## ------------------ ##
	## C compiler checks. ##
	## ------------------ ##
	AC_PROG_CC
	AC_DEFUN([gl_CXX_CHOICE_DEFAULT_NO])
	M4_EARLY

	# Maintainer note - comment this line out if you plan to rerun
	# GNULIB_POSIXCHECK testing to see if M4 should be using more modules.
	# Leave it uncommented for normal releases, for faster ./configure.
	gl_ASSERT_NO_GNULIB_POSIXCHECK

	AC_SYS_LARGEFILE
	AC_PROG_CPP
	AM_PROG_CC_C_O
	M4_CHECK_DEBUGGING


	## --------------------------- ##
	## C compiler characteristics. ##
	## --------------------------- ##
	AC_TYPE_SIZE_T
	AC_CHECK_SIZEOF([long long int])

	AS_CASE([$host], [--os2*], [OS2_LDFLAGS=-Zargs-resp])
	AC_SUBST([OS2_LDFLAGS])


	## ----------------------- ##
	## Libtool initialization. ##
	## ----------------------- ##
	LT_PREREQ([2.2])
	LT_INIT([shared dlopen win32-dll])

	AC_ARG_ENABLE([gcc-warnings],
	[AS_HELP_STRING([--enable-gcc-warnings],
	[turn on lots of GCC warnings (for developers)])],
	[case $enableval in
	yes\|no) ;;
	*) AC_MSG_ERROR([bad value $enableval for gcc-warnings option]) ;;
	esac
	gl_gcc_warnings=$enableval],
	[gl_gcc_warnings=no]
	)

	if test "$gl_gcc_warnings" = yes; then
	gl_WARN_ADD([-Werror], [WERROR_CFLAGS])
	AC_SUBST([WERROR_CFLAGS])

	# This, $nw, is the list of warnings we disable.
	nw=
	nw="$nw -Waggregate-return" # K&R is anachronistic
	nw="$nw -Wtraditional-conversion" # K&R is anachronistic
	nw="$nw -Wundef" # K&R is anachronistic
	nw="$nw -Wlong-long" # C90 is anachronistic
	nw="$nw -Wsystem-headers" # Don't let system headers trigger warnings
	nw="$nw -Wpadded" # Our structs are not packed
	nw="$nw -Wformat-nonliteral" # Needed in builtin.c
	nw="$nw -Wconversion" # Too many warnings for now
	nw="$nw -Wsign-conversion" # Too many warnings for now
	nw="$nw -Wcast-qual" # Too many warnings for now
	nw="$nw -Wswitch-enum" # Too many warnings for now
	# gcc 4.4.6 complains enum-compare is C++ only; gcc 4.7.0 implies it in -Wall
	nw="$nw -Wenum-compare"

	# Gnulib uses '#pragma GCC diagnostic push' to silence some
	# warnings, but older gcc doesn't support this.
	AC_CACHE_CHECK([whether pragma GCC diagnostic push works],
	[M4_cv_gcc_pragma_push_works], [
	save_CFLAGS=$CFLAGS
	CFLAGS='-Wunknown-pragmas -Werror'
	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
	#pragma GCC diagnostic push
	#pragma GCC diagnostic pop
	]])],
	[M4_cv_gcc_pragma_push_works=yes],
	[M4_cv_gcc_pragma_push_works=no])
	CFLAGS=$save_CFLAGS])
	if test $M4_cv_gcc_pragma_push_works = no; then
	nw="$nw -Wmissing-prototypes"
	nw="$nw -Wmissing-declarations"
	nw="$nw -Wunreachable-code"
	fi

	gl_MANYWARN_ALL_GCC([ws])
	gl_MANYWARN_COMPLEMENT([ws], [$ws], [$nw])
	for w in $ws; do
	gl_WARN_ADD([$w])
	done

	gl_WARN_ADD([-fdiagnostics-show-option])
	gl_WARN_ADD([-funit-at-a-time])

	AC_SUBST([WARN_CFLAGS])

	AH_VERBATIM([FORTIFY_SOURCE],
	[/* Enable compile-time and run-time bounds-checking, and some warnings,
	without upsetting newer glibc. */
	#if defined __OPTIMIZE__ && __OPTIMIZE__
	# define _FORTIFY_SOURCE 2
	#endif
	])
	fi

	# Use gcc's -pipe option if available: for faster compilation.
	case "$CFLAGS" in
	-pipe ) ;;
	* ) _LT_COMPILER_OPTION([if $compiler supports -pipe],
	[M4_cv_prog_compiler_pipe],
	[-pipe -c conftest.$ac_ext], [],
	[CFLAGS="$CFLAGS -pipe"])
	;;
	esac


	## ------------------------------- ##
	## Dynamic Loader Characteristics. ##
	## ------------------------------- ##

	LT_LIB_DLLOAD
	LT_SYS_SYMBOL_USCORE

	LT_SYS_MODULE_EXT

	if test yes = "$sys_symbol_underscore"; then
	libm4_shlibext=$libltdl_cv_shlibext

	AC_MSG_CHECKING([whether dlsym requires underscore prefixed symbols])
	AC_CACHE_VAL([libm4_cv_sys_dlsym_uscore], [dnl
	libname=conftmod # stay within 8.3 filename limits!
	cat >$libname.$ac_ext <<_M4_EOF
	[#line $LINENO "configure"
	#include "confdefs.h"
	/* When -fvisibility=hidden is used, assume the code has been annotated
	correspondingly for the symbols needed. */
	#if defined __GNUC__ && (((__GNUC__ == 3) && (__GNUC_MINOR__ >= 3)) \|\| (__GNUC__ > 3))
	int fnord () __attribute__((visibility("default")));
	#endif
	int fnord () { return 42; }]
	_M4_EOF

	# fn_module_cmds module_cmds
	# Execute tilde-delimited MODULE_CMDS with environment primed for
	# ${module_cmds} or ${archive_cmds} type content.
	fn_module_cmds ()
	{( # subshell avoids polluting parent global environment
	module_cmds_save_ifs=$IFS; IFS='~'
	for cmd in $1; do
	IFS=$module_cmds_save_ifs
	libobjs=$libname.$ac_objext; lib=$libname$libm4_shlibext
	rpath=/not-exists; soname=$libname$libm4_shlibext; output_objdir=.
	major=; versuffix=; verstring=; deplibs=
	ECHO=echo; wl=$lt_prog_compiler_wl; allow_undefined_flag=
	eval $cmd
	done
	IFS=$module_cmds_save_ifs
	)}

	# Compile a loadable module using libtool macro expansion results.
	$CC $pic_flag -c $libname.$ac_ext
	fn_module_cmds "${module_cmds:-$archive_cmds}"

	# Try to fetch fnord with dlsym().
	libm4_dlunknown=0; libm4_dlnouscore=1; libm4_dluscore=2
	cat >conftest.$ac_ext <<_M4_EOF
	[#line $LINENO "configure"
	#include "confdefs.h"
	#if HAVE_DLFCN_H
	#include <dlfcn.h>
	#endif
	#include <stdio.h>
	#ifndef RTLD_GLOBAL
	# ifdef DL_GLOBAL
	# define RTLD_GLOBAL DL_GLOBAL
	# else
	# define RTLD_GLOBAL 0
	# endif
	#endif
	#ifndef RTLD_NOW
	# ifdef DL_NOW
	# define RTLD_NOW DL_NOW
	# else
	# define RTLD_NOW 0
	# endif
	#endif
	int main () {
	void *handle = dlopen ("`pwd`/$libname$libm4_shlibext", RTLD_GLOBAL\|RTLD_NOW);
	int status = $libm4_dlunknown;
	if (handle) {
	if (dlsym (handle, "fnord"))
	status = $libm4_dlnouscore;
	else {
	if (dlsym (handle, "_fnord"))
	status = $libm4_dluscore;
	else
	puts (dlerror ());
	}
	dlclose (handle);
	} else
	puts (dlerror ());
	return status;
	}]
	_M4_EOF
	if AC_TRY_EVAL(ac_link) && test -s "conftest$ac_exeext" 2>/dev/null; then
	(./conftest; exit; ) >&AS_MESSAGE_LOG_FD 2>/dev/null
	libm4_status=$?
	case x$libm4_status in
	x$libm4_dlnouscore) libm4_cv_sys_dlsym_uscore=no ;;
	x$libm4_dluscore) libm4_cv_sys_dlsym_uscore=yes ;;
	x*) libm4_cv_sys_dlsym_uscore=unknown ;;
	esac
	fi
	rm -rf conftest* $libname*
	])
	sys_dlsym_uscore=$libm4_cv_sys_dlsym_uscore
	AC_MSG_RESULT($sys_dlsym_uscore)
	if test yes = "$sys_dlsym_uscore"; then
	AC_DEFINE([DLSYM_USCORE], [1],
	[Define if dlsym() requires a leading underscore in symbol names.])
	fi
	fi

	AC_DEFINE_UNQUOTED([PATH_SEPARATOR], ['$PATH_SEPARATOR'],
	[Define this to system search path delimiter])


	## ---------------- ##
	## Gettext support. ##
	## ---------------- ##
	AM_GNU_GETTEXT([external])
	AM_GNU_GETTEXT_NEED([need-formatstring-macros])
	AM_GNU_GETTEXT_VERSION([0.16])
	M4_GNU_GETTEXT


	## --------------- ##
	## Gnulib support. ##
	## --------------- ##
	M4_INIT

	gl_VERSION_ETC

	# Gnulib doesn't always do things quite the way M4 would like...
	M4_ERROR
	M4_GETOPT
	M4_OBSTACK
	M4_REGEX
	M4_RENAME


	## ------------------------- ##
	## C headers required by M4. ##
	## ------------------------- ##
	AC_CHECK_HEADERS_ONCE([limits.h])

	if test $ac_cv_header_stdbool_h = yes; then
	INCLUDE_STDBOOL_H='#include <stdbool.h>'
	else
	INCLUDE_STDBOOL_H='#include <gnu/stdbool.h>'
	fi
	AC_SUBST([INCLUDE_STDBOOL_H])


	## --------------------------------- ##
	## Library functions required by M4. ##
	## --------------------------------- ##
	AC_CHECK_FUNCS_ONCE([calloc strerror])

	AM_WITH_DMALLOC

	M4_SYS_STACKOVF

	# This is for the modules
	AC_STRUCT_TM
	AC_FUNC_STRFTIME
	AC_CHECK_FUNCS_ONCE([getcwd gethostname mktime uname])


	## ------------------ ##
	## Configure options. ##
	## ------------------ ##

	M4_LIB_GMP
	AM_CONDITIONAL([USE_GMP], [test "x$USE_GMP" = xyes])
	M4_SYSCMD


	## -------- ##
	## Outputs. ##
	## -------- ##
	AC_CONFIG_FILES([
	Makefile
	doc/Makefile
	m4/gnu/Makefile
	m4/system.h:m4/system_.h
	tests/atlocal
	tests/gnu/Makefile
	])

	AC_OUTPUT