configure.ac - platform/external/ltrace - Git at Google

 # -*- Autoconf -*-
 # This file is part of ltrace.
 # Copyright (C) 2010,2012,2013,2014 Petr Machata, Red Hat Inc.
 # Copyright (C) 2010,2011 Joe Damato
 # Copyright (C) 2010 Marc Kleine-Budde
 # Copyright (C) 2010 Zachary T Welch
 #
 # This program 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 2 of the
 # License, or (at your option) any later version.
 #
 # This program 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, write to the Free Software
 # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 # 02110-1301 USA

 # Process this file with autoconf to produce a configure script.
 AC_PREREQ([2.65])

 AC_INIT([ltrace],[0.7.91],[ltrace-devel@lists.alioth.debian.org],
 	[ltrace],[http://ltrace.alioth.debian.org/])
 AC_CONFIG_HEADERS([config.h])
 AC_CONFIG_SRCDIR(libltrace.c)
 AC_CONFIG_MACRO_DIR([config/m4])
 AC_CONFIG_AUX_DIR([config/autoconf])
 AC_CANONICAL_BUILD
 AC_CANONICAL_HOST

 case "${host_os}" in
     linux-gnu*) HOST_OS="linux-gnu" ;;
     linux-uclibc*) HOST_OS="linux-gnu" ;;
     *)		AC_MSG_ERROR([unkown host-os ${host_os}]) ;;
 esac
 AC_SUBST(HOST_OS)

 case "${host_cpu}" in
     arm*|sa110)		HOST_CPU="arm" ;;
     cris*)		HOST_CPU="cris" ;;
     mips*)		HOST_CPU="mips" ;;
     powerpc|powerpc64)	HOST_CPU="ppc" ;;
     sun4u|sparc64)	HOST_CPU="sparc" ;;
     s390x)		HOST_CPU="s390" ;;
     i?86|x86_64)	HOST_CPU="x86" ;;
     *)			HOST_CPU="${host_cpu}" ;;
 esac
 AC_SUBST(HOST_CPU)

 # Checks for programs.
 AC_PROG_CC
 LT_INIT
 # libtool-2:  LT_INIT()
 AM_INIT_AUTOMAKE([foreign no-exeext dist-bzip2])
 AM_MAINTAINER_MODE

 #
 # We use stat(2).  Even though we don't care about the file size or
 # inode number, stat will fail with EOVERFLOW if either of these
 # exceeds 32 bits.  We therefore ask for stat64 if available.  Do this
 # test as soon as possible, as large file support may influence
 # whether other headers are available.
 #
 AC_SYS_LARGEFILE

 AC_ARG_WITH([libelf],
   AS_HELP_STRING([--with-libelf], [Prefix of libelf headers/library]),
   [case "${withval}" in
   (no)
     AC_MSG_ERROR([*** libelf is a required dependency])
     ;;
   (yes)
     AC_MSG_ERROR([*** --with-libelf requires you to specify a path])
     ;;
   (*)
     AM_CPPFLAGS="${AM_CPPFLAGS} -I${withval}/include"
     AM_LDFLAGS="${AM_LDFLAGS} -L${withval}/lib"
     libelf_LD_LIBRARY_PATH="${withval}/lib"
     ;;
 esac],[])

 # Checks for libraries.

 saved_CPPFLAGS="${CPPFLAGS}"
 saved_LDFLAGS="${LDFLAGS}"
 CPPFLAGS="${CPPFLAGS} ${AM_CPPFLAGS}"
 LDFLAGS="${LDFLAGS} ${AM_LDFLAGS}"
 # libelf
 AC_CHECK_HEADERS([elf.h gelf.h],,
 	[AC_MSG_ERROR([*** libelf.h or gelf.h not found on your system])]
 )
 AC_CHECK_LIB([elf], [elf_begin],,
 	[AC_MSG_ERROR([*** libelf not found on your system])]
 )
 CPPFLAGS="${saved_CPPFLAGS}"
 LDFLAGS="${saved_LDFLAGS}"


 # HAVE_LIBIBERTY
 AC_CHECK_LIB([iberty], [cplus_demangle], [
 	AC_DEFINE([HAVE_LIBIBERTY], [1], [we have libiberty])
 	liberty_LIBS="-liberty"], [
 	liberty_LIBS=""])
 AC_SUBST(liberty_LIBS)


 # HAVE_LIBSUPC__
 AC_CHECK_LIB([supc++], [__cxa_demangle], [
 	AC_DEFINE([HAVE_LIBSUPC__], [1], [we have libsupc++])
 	libsupcxx_LIBS="-lsupc++"], [
 	libsupcxx_LIBS=""])
 AC_SUBST(libsupcxx_LIBS)


 # HAVE_LIBSTDC__
 AC_CHECK_LIB([stdc++], [__cxa_demangle], [
 	AC_DEFINE([HAVE_LIBSTDC__], [1], [we have libstdc++])
 	libstdcxx_LIBS="-lstdc++"], [
 	libstdcxx_LIBS=""])
 AC_SUBST(libstdcxx_LIBS)


 dnl Check security_get_boolean_active availability.
 AC_CHECK_HEADERS(selinux/selinux.h)
 AC_CHECK_LIB(selinux, security_get_boolean_active)

 dnl Whether (and which) elfutils libdw.so to use for unwinding.
 AC_ARG_WITH(elfutils,
   AS_HELP_STRING([--with-elfutils], [Use elfutils libdwfl unwinding support]),
   [case "${withval}" in
   (yes|no) enable_elfutils=$withval;;
   (*) enable_elfutils=yes
     AM_CPPFLAGS="${AM_CPPFLAGS} -I${withval}/include"
     AM_LDFLAGS="${AM_LDFLAGS} -L${withval}/lib"
     elfutils_LD_LIBRARY_PATH="${withval}/lib:${withval}/lib/elfutils"
     ;;
 esac],[enable_elfutils=maybe])

 dnl Check whether we have the elfutils libdwfl.h header installed.
 saved_CPPFLAGS="${CPPFLAGS}"
 CPPFLAGS="${CPPFLAGS} ${AM_CPPFLAGS}"
 AC_CHECK_HEADERS([elfutils/libdwfl.h],[have_libdwfl_h=yes])
 CPPFLAGS="${saved_CPPFLAGS}"

 dnl And whether libdw.so provides the unwinding functions.
 saved_LDFLAGS="${LDFLAGS}"
 LDFLAGS="${LDFLAGS} ${AM_LDFLAGS}"
 AC_CHECK_LIB([dw], [dwfl_getthread_frames], [have_libdw_dwfl_frames=yes])
 LDFLAGS="${saved_LDFLAGS}"

 AC_MSG_CHECKING([whether to use elfutils libdwfl unwinding support])
 case "${enable_elfutils}" in
 (yes|maybe)
   if test x$have_libdwfl_h = xyes -a x$have_libdw_dwfl_frames = xyes; then
     enable_elfutils=yes
   elif test $enable_elfutils = maybe; then
     enable_elfutils=no
   else
     AC_MSG_RESULT([$enable_elfutils])
     AC_MSG_ERROR([Missing elfutils/libdwfl.h or dwfl_getthread_frames not in libdw.so])
   fi
   ;;
 (*) ;;
 esac
 AC_MSG_RESULT([$enable_elfutils])

 if test x"$enable_elfutils" = xyes; then
   libdw_LIBS=-ldw
   AC_SUBST(libdw_LIBS)
   AC_DEFINE([HAVE_LIBDW], [1], [we have elfutils libdw])
 fi

 # HAVE_LIBUNWIND
 AC_ARG_WITH(libunwind,
   AS_HELP_STRING([--with-libunwind], [Use libunwind frame unwinding support]),
   [case "${withval}" in
   (yes|no) enable_libunwind=$withval;;
   (*) enable_libunwind=yes
     AM_CPPFLAGS="${AM_CPPFLAGS} -I${withval}/include"
     AM_LDFLAGS="${AM_LDFLAGS} -L${withval}/lib"
     libunwind_LD_LIBRARY_PATH="${withval}/lib"
     ;;
 esac],[enable_libunwind=maybe])

 saved_CPPFLAGS="${CPPFLAGS}"
 CPPFLAGS="${CPPFLAGS} ${AM_CPPFLAGS}"
 AC_CHECK_HEADERS([libunwind.h], [have_libunwind_h=yes])
 AC_CHECK_HEADERS([libunwind-ptrace.h], [have_libunwind_ptrace_h=yes])
 CPPFLAGS="${saved_CPPFLAGS}"

 AC_MSG_CHECKING([whether to use libunwind support])
 case "${enable_libunwind}" in
 (yes|maybe)
   if test x$have_libunwind_h = xyes -o x$have_libunwind_ptrace_h = xyes; then
     enable_libunwind=yes
   elif test $enable_libunwind = maybe; then
     enable_libunwind=no
   else
     AC_MSG_RESULT([$enable_libunwind])
     AC_MSG_ERROR([libunwind.h or libunwind-ptrace.h cannot be found])
   fi
   ;;
 (*) ;;
 esac
 AC_MSG_RESULT([$enable_libunwind])

 if test x"$enable_libunwind" = xyes; then
   case "${host_cpu}" in
       arm*|sa110)         UNWIND_ARCH="arm" ;;
       i?86)               UNWIND_ARCH="x86" ;;
       powerpc)            UNWIND_ARCH="ppc32" ;;
       powerpc64)          UNWIND_ARCH="ppc64" ;;
       mips*)              UNWIND_ARCH="mips" ;;
       *)                  UNWIND_ARCH="${host_cpu}" ;;
   esac

   saved_LDFLAGS="${LDFLAGS}"
   LDFLAGS="${LDFLAGS} ${AM_LDFLAGS}"
   AC_CHECK_LIB([unwind], [backtrace], [libunwind_LIBS=-lunwind],
 	       [AC_MSG_ERROR([Couldn't find or use libunwind.])])

   AC_CHECK_LIB([unwind-${UNWIND_ARCH}], [_U${UNWIND_ARCH}_init_remote],
 	       [libunwind_LIBS="-lunwind-${UNWIND_ARCH} $libunwind_LIBS"],
 	       [AC_MSG_ERROR([Couldn't find or use libunwind-${UNWIND_ARCH}.])],
 	       [$libunwind_LIBS])

   AC_CHECK_LIB([unwind-ptrace], [_UPT_create],
 	       [libunwind_LIBS="-lunwind-ptrace $libunwind_LIBS"],
 	       [AC_MSG_ERROR([Couldn't find or use libunwind-ptrace.])],
 	       [$libunwind_LIBS])

   AC_SUBST(libunwind_LIBS)
   AC_DEFINE([HAVE_LIBUNWIND], [1], [we have libunwind])
   LDFLAGS="${saved_LDFLAGS}"
 fi

 if test x"$enable_elfutils" = xyes -a x"$enable_libunwind" = xyes; then
   AC_MSG_ERROR([Cannot enable both --with-libunwind and --with-elfutils])
 fi

 if test x"$enable_elfutils" = xyes -o x"$enable_libunwind" = xyes; then
   AC_DEFINE([HAVE_UNWINDER], [1], [we have an unwinder available])
 fi

 saved_CPPFLAGS="${CPPFLAGS}"
 saved_LDFLAGS="${LDFLAGS}"
 CPPFLAGS="${CPPFLAGS} ${AM_CPPFLAGS}"
 LDFLAGS="${LDFLAGS} ${AM_LDFLAGS}"
 # HAVE_ELF_C_READ_MMAP
 AC_MSG_CHECKING([whether elf_begin accepts ELF_C_READ_MMAP])
 AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <gelf.h>]], [[
 int main () {
 	Elf *elf = elf_begin(4, ELF_C_READ_MMAP, 0);
 	return 0;
 }
 	]])],[
 	AC_DEFINE([HAVE_ELF_C_READ_MMAP], [1], [we have read mmap support])
 	AC_MSG_RESULT([yes])],[
 	AC_MSG_RESULT([no])])

 saved_CFLAGS="${CFLAGS}"
 CFLAGS="${CFLAGS} -Wall -Werror"
 AC_MSG_CHECKING([whether elf_hash takes a char* argument])
 AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <libelf.h>]], [[
 	(void) elf_hash("name");
 	]])],
 	[AC_DEFINE([ELF_HASH_TAKES_CHARP], [1],
 		[elf_hash() takes char* (as opposed to unsigned char *)])
 	 AC_MSG_RESULT([yes])],
 	[AC_MSG_RESULT([no])])
 CFLAGS="${saved_CFLAGS}"
 CPPFLAGS="${saved_CPPFLAGS}"
 LDFLAGS="${saved_LDFLAGS}"

 AM_CPPFLAGS=" \
 	-DSYSCONFDIR="'\"$(sysconfdir)\"'" \
 	-DPKGDATADIR="'\"$(pkgdatadir)\"'" \
 	${AM_CPPFLAGS} \
 	-I\$(top_srcdir)/sysdeps/${HOST_OS}/${HOST_CPU} \
 	-I\$(top_srcdir)/sysdeps/${HOST_OS} \
 	-I\$(top_srcdir)/sysdeps \
 	-I\$(top_srcdir) \
 "

 # Checks for header files.
 AC_CHECK_HEADERS([ \
 	fcntl.h \
 	limits.h \
 	stddef.h \
 	stdint.h \
 	stdlib.h \
 	string.h \
 	sys/ioctl.h \
 	sys/param.h \
 	sys/time.h \
 	unistd.h \
 ])

 # Checks for typedefs, structures, and compiler characteristics.
 AC_TYPE_UID_T
 AC_C_INLINE
 AC_TYPE_PID_T
 AC_TYPE_SIZE_T
 AC_CHECK_SIZEOF([long])


 # Checks for library functions.
 AC_FUNC_FORK
 AC_CHECK_FUNCS([ \
 	alarm \
 	atexit \
 	gettimeofday \
 	memset \
 	strchr \
 	strdup \
 	strerror \
 	strsignal \
 	strtol \
 	strtoul \
 ])

 #
 # Define HAVE_OPEN_MEMSTREAM if open_memstream is available.  glibc
 # before 2.10, eglibc and uClibc all need _GNU_SOURCE defined for
 # open_memstream to become visible, so check for that as well.  If
 # unavailable, require that tmpfile be present.  There's no
 # HAVE_TMPFILE, as we plain require that to be present as a fallback.
 #
 AC_CHECK_FUNCS([open_memstream], [],
 	[AC_MSG_CHECKING([for open_memstream with _GNU_SOURCE])
 	 AC_LINK_IFELSE(
 		[AC_LANG_PROGRAM([[#define _GNU_SOURCE 1
 				   #include <stdio.h>]],
 				 [[char *buf; size_t sz;
 				   return open_memstream(&buf, &sz) != 0;]])],

 		 [AC_MSG_RESULT([yes])
 		  AC_DEFINE([HAVE_OPEN_MEMSTREAM], [1],
 			[Define if open_memstream exists.])],

 		 [AC_MSG_RESULT([no])
 		  AC_CHECK_FUNC([tmpfile], [],
 			[AC_MSG_ERROR(
 			    [Either open_memstream or tmpfile required.])])])])

 #
 # Define HAVE_GETOPT_LONG if that is available.
 #
 AC_CHECK_HEADER([getopt.h], [AC_CHECK_FUNCS([getopt_long])])

 #
 # Debugging
 #
 AC_MSG_CHECKING([whether to enable debugging])
 AC_ARG_ENABLE(debug,
     AS_HELP_STRING([--enable-debug], [enable debugging @<:@default=no@:>@]),
 	[case "$enableval" in
 	y | yes) CONFIG_DEBUG=yes ;;
         *) CONFIG_DEBUG=no ;;
     esac],
     [CONFIG_DEBUG=no])
 AC_MSG_RESULT([${CONFIG_DEBUG}])
 if test "${CONFIG_DEBUG}" = "yes"; then
     AC_DEFINE(DEBUG, 1, [debugging])
 fi

 # Ignore the compiler's warnings at your own risk.
 AM_CFLAGS="${AM_CFLAGS} -Wall -Wsign-compare -Wfloat-equal -Wformat-security"
 AC_ARG_ENABLE([werror],
     AS_HELP_STRING([--disable-werror], [disable use of -Werror]),
     [enable_werror=$enableval], [enable_werror=yes])
 if test x$enable_werror = xyes; then
     AM_CFLAGS="${AM_CFLAGS} -Werror"
 fi

 AC_ARG_ENABLE([valgrind],
     AS_HELP_STRING([--enable-valgrind],[run all tests under valgrind]),
     [use_valgrind=$enableval], [use_valgrind=no])
 if test x$use_valgrind = xyes; then
     AC_CHECK_PROG(HAVE_VALGRIND, valgrind, yes, no)
     if test x$HAVE_VALGRIND = xno; then
         AC_MSG_ERROR([valgrind not found])
     fi
 fi
 AM_CONDITIONAL(USE_VALGRIND, test "$use_valgrind" = yes)

 AC_SUBST(AM_CPPFLAGS)
 AC_SUBST(AM_CFLAGS)
 AC_SUBST(AM_LDFLAGS)
 AC_SUBST(libelf_LD_LIBRARY_PATH)
 AC_SUBST(elfutils_LD_LIBRARY_PATH)
 AC_SUBST(libunwind_LD_LIBRARY_PATH)

 AC_CONFIG_FILES([
 	Makefile
 	sysdeps/Makefile
 	sysdeps/linux-gnu/Makefile
 	sysdeps/linux-gnu/aarch64/Makefile
 	sysdeps/linux-gnu/alpha/Makefile
 	sysdeps/linux-gnu/arm/Makefile
 	sysdeps/linux-gnu/cris/Makefile
 	sysdeps/linux-gnu/ia64/Makefile
 	sysdeps/linux-gnu/m68k/Makefile
 	sysdeps/linux-gnu/metag/Makefile
 	sysdeps/linux-gnu/mips/Makefile
 	sysdeps/linux-gnu/ppc/Makefile
 	sysdeps/linux-gnu/s390/Makefile
 	sysdeps/linux-gnu/sparc/Makefile
 	sysdeps/linux-gnu/x86/Makefile
 	testsuite/Makefile
 	testsuite/ltrace.main/Makefile
 	testsuite/ltrace.minor/Makefile
 	testsuite/ltrace.torture/Makefile
 ])
 AC_OUTPUT
	# -- Autoconf --
	# This file is part of ltrace.
	# Copyright (C) 2010,2012,2013,2014 Petr Machata, Red Hat Inc.
	# Copyright (C) 2010,2011 Joe Damato
	# Copyright (C) 2010 Marc Kleine-Budde
	# Copyright (C) 2010 Zachary T Welch
	#
	# This program 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 2 of the
	# License, or (at your option) any later version.
	#
	# This program 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, write to the Free Software
	# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
	# 02110-1301 USA

	# Process this file with autoconf to produce a configure script.
	AC_PREREQ([2.65])

	AC_INIT([ltrace],[0.7.91],[ltrace-devel@lists.alioth.debian.org],
	[ltrace],[http://ltrace.alioth.debian.org/])
	AC_CONFIG_HEADERS([config.h])
	AC_CONFIG_SRCDIR(libltrace.c)
	AC_CONFIG_MACRO_DIR([config/m4])
	AC_CONFIG_AUX_DIR([config/autoconf])
	AC_CANONICAL_BUILD
	AC_CANONICAL_HOST

	case "${host_os}" in
	linux-gnu*) HOST_OS="linux-gnu" ;;
	linux-uclibc*) HOST_OS="linux-gnu" ;;
	*) AC_MSG_ERROR([unkown host-os ${host_os}]) ;;
	esac
	AC_SUBST(HOST_OS)

	case "${host_cpu}" in
	arm*\|sa110) HOST_CPU="arm" ;;
	cris*) HOST_CPU="cris" ;;
	mips*) HOST_CPU="mips" ;;
	powerpc\|powerpc64) HOST_CPU="ppc" ;;
	sun4u\|sparc64) HOST_CPU="sparc" ;;
	s390x) HOST_CPU="s390" ;;
	i?86\|x86_64) HOST_CPU="x86" ;;
	*) HOST_CPU="${host_cpu}" ;;
	esac
	AC_SUBST(HOST_CPU)

	# Checks for programs.
	AC_PROG_CC
	LT_INIT
	# libtool-2: LT_INIT()
	AM_INIT_AUTOMAKE([foreign no-exeext dist-bzip2])
	AM_MAINTAINER_MODE

	#
	# We use stat(2). Even though we don't care about the file size or
	# inode number, stat will fail with EOVERFLOW if either of these
	# exceeds 32 bits. We therefore ask for stat64 if available. Do this
	# test as soon as possible, as large file support may influence
	# whether other headers are available.
	#
	AC_SYS_LARGEFILE

	AC_ARG_WITH([libelf],
	AS_HELP_STRING([--with-libelf], [Prefix of libelf headers/library]),
	[case "${withval}" in
	(no)
	AC_MSG_ERROR([*** libelf is a required dependency])
	;;
	(yes)
	AC_MSG_ERROR([*** --with-libelf requires you to specify a path])
	;;
	(*)
	AM_CPPFLAGS="${AM_CPPFLAGS} -I${withval}/include"
	AM_LDFLAGS="${AM_LDFLAGS} -L${withval}/lib"
	libelf_LD_LIBRARY_PATH="${withval}/lib"
	;;
	esac],[])

	# Checks for libraries.

	saved_CPPFLAGS="${CPPFLAGS}"
	saved_LDFLAGS="${LDFLAGS}"
	CPPFLAGS="${CPPFLAGS} ${AM_CPPFLAGS}"
	LDFLAGS="${LDFLAGS} ${AM_LDFLAGS}"
	# libelf
	AC_CHECK_HEADERS([elf.h gelf.h],,
	[AC_MSG_ERROR([*** libelf.h or gelf.h not found on your system])]
	)
	AC_CHECK_LIB([elf], [elf_begin],,
	[AC_MSG_ERROR([*** libelf not found on your system])]
	)
	CPPFLAGS="${saved_CPPFLAGS}"
	LDFLAGS="${saved_LDFLAGS}"


	# HAVE_LIBIBERTY
	AC_CHECK_LIB([iberty], [cplus_demangle], [
	AC_DEFINE([HAVE_LIBIBERTY], [1], [we have libiberty])
	liberty_LIBS="-liberty"], [
	liberty_LIBS=""])
	AC_SUBST(liberty_LIBS)


	# HAVE_LIBSUPC__
	AC_CHECK_LIB([supc++], [__cxa_demangle], [
	AC_DEFINE([HAVE_LIBSUPC__], [1], [we have libsupc++])
	libsupcxx_LIBS="-lsupc++"], [
	libsupcxx_LIBS=""])
	AC_SUBST(libsupcxx_LIBS)


	# HAVE_LIBSTDC__
	AC_CHECK_LIB([stdc++], [__cxa_demangle], [
	AC_DEFINE([HAVE_LIBSTDC__], [1], [we have libstdc++])
	libstdcxx_LIBS="-lstdc++"], [
	libstdcxx_LIBS=""])
	AC_SUBST(libstdcxx_LIBS)


	dnl Check security_get_boolean_active availability.
	AC_CHECK_HEADERS(selinux/selinux.h)
	AC_CHECK_LIB(selinux, security_get_boolean_active)

	dnl Whether (and which) elfutils libdw.so to use for unwinding.
	AC_ARG_WITH(elfutils,
	AS_HELP_STRING([--with-elfutils], [Use elfutils libdwfl unwinding support]),
	[case "${withval}" in
	(yes\|no) enable_elfutils=$withval;;
	(*) enable_elfutils=yes
	AM_CPPFLAGS="${AM_CPPFLAGS} -I${withval}/include"
	AM_LDFLAGS="${AM_LDFLAGS} -L${withval}/lib"
	elfutils_LD_LIBRARY_PATH="${withval}/lib:${withval}/lib/elfutils"
	;;
	esac],[enable_elfutils=maybe])

	dnl Check whether we have the elfutils libdwfl.h header installed.
	saved_CPPFLAGS="${CPPFLAGS}"
	CPPFLAGS="${CPPFLAGS} ${AM_CPPFLAGS}"
	AC_CHECK_HEADERS([elfutils/libdwfl.h],[have_libdwfl_h=yes])
	CPPFLAGS="${saved_CPPFLAGS}"

	dnl And whether libdw.so provides the unwinding functions.
	saved_LDFLAGS="${LDFLAGS}"
	LDFLAGS="${LDFLAGS} ${AM_LDFLAGS}"
	AC_CHECK_LIB([dw], [dwfl_getthread_frames], [have_libdw_dwfl_frames=yes])
	LDFLAGS="${saved_LDFLAGS}"

	AC_MSG_CHECKING([whether to use elfutils libdwfl unwinding support])
	case "${enable_elfutils}" in
	(yes\|maybe)
	if test x$have_libdwfl_h = xyes -a x$have_libdw_dwfl_frames = xyes; then
	enable_elfutils=yes
	elif test $enable_elfutils = maybe; then
	enable_elfutils=no
	else
	AC_MSG_RESULT([$enable_elfutils])
	AC_MSG_ERROR([Missing elfutils/libdwfl.h or dwfl_getthread_frames not in libdw.so])
	fi
	;;
	(*) ;;
	esac
	AC_MSG_RESULT([$enable_elfutils])

	if test x"$enable_elfutils" = xyes; then
	libdw_LIBS=-ldw
	AC_SUBST(libdw_LIBS)
	AC_DEFINE([HAVE_LIBDW], [1], [we have elfutils libdw])
	fi

	# HAVE_LIBUNWIND
	AC_ARG_WITH(libunwind,
	AS_HELP_STRING([--with-libunwind], [Use libunwind frame unwinding support]),
	[case "${withval}" in
	(yes\|no) enable_libunwind=$withval;;
	(*) enable_libunwind=yes
	AM_CPPFLAGS="${AM_CPPFLAGS} -I${withval}/include"
	AM_LDFLAGS="${AM_LDFLAGS} -L${withval}/lib"
	libunwind_LD_LIBRARY_PATH="${withval}/lib"
	;;
	esac],[enable_libunwind=maybe])

	saved_CPPFLAGS="${CPPFLAGS}"
	CPPFLAGS="${CPPFLAGS} ${AM_CPPFLAGS}"
	AC_CHECK_HEADERS([libunwind.h], [have_libunwind_h=yes])
	AC_CHECK_HEADERS([libunwind-ptrace.h], [have_libunwind_ptrace_h=yes])
	CPPFLAGS="${saved_CPPFLAGS}"

	AC_MSG_CHECKING([whether to use libunwind support])
	case "${enable_libunwind}" in
	(yes\|maybe)
	if test x$have_libunwind_h = xyes -o x$have_libunwind_ptrace_h = xyes; then
	enable_libunwind=yes
	elif test $enable_libunwind = maybe; then
	enable_libunwind=no
	else
	AC_MSG_RESULT([$enable_libunwind])
	AC_MSG_ERROR([libunwind.h or libunwind-ptrace.h cannot be found])
	fi
	;;
	(*) ;;
	esac
	AC_MSG_RESULT([$enable_libunwind])

	if test x"$enable_libunwind" = xyes; then
	case "${host_cpu}" in
	arm*\|sa110) UNWIND_ARCH="arm" ;;
	i?86) UNWIND_ARCH="x86" ;;
	powerpc) UNWIND_ARCH="ppc32" ;;
	powerpc64) UNWIND_ARCH="ppc64" ;;
	mips*) UNWIND_ARCH="mips" ;;
	*) UNWIND_ARCH="${host_cpu}" ;;
	esac

	saved_LDFLAGS="${LDFLAGS}"
	LDFLAGS="${LDFLAGS} ${AM_LDFLAGS}"
	AC_CHECK_LIB([unwind], [backtrace], [libunwind_LIBS=-lunwind],
	[AC_MSG_ERROR([Couldn't find or use libunwind.])])

	AC_CHECK_LIB([unwind-${UNWIND_ARCH}], [_U${UNWIND_ARCH}_init_remote],
	[libunwind_LIBS="-lunwind-${UNWIND_ARCH} $libunwind_LIBS"],
	[AC_MSG_ERROR([Couldn't find or use libunwind-${UNWIND_ARCH}.])],
	[$libunwind_LIBS])

	AC_CHECK_LIB([unwind-ptrace], [_UPT_create],
	[libunwind_LIBS="-lunwind-ptrace $libunwind_LIBS"],
	[AC_MSG_ERROR([Couldn't find or use libunwind-ptrace.])],
	[$libunwind_LIBS])

	AC_SUBST(libunwind_LIBS)
	AC_DEFINE([HAVE_LIBUNWIND], [1], [we have libunwind])
	LDFLAGS="${saved_LDFLAGS}"
	fi

	if test x"$enable_elfutils" = xyes -a x"$enable_libunwind" = xyes; then
	AC_MSG_ERROR([Cannot enable both --with-libunwind and --with-elfutils])
	fi

	if test x"$enable_elfutils" = xyes -o x"$enable_libunwind" = xyes; then
	AC_DEFINE([HAVE_UNWINDER], [1], [we have an unwinder available])
	fi

	saved_CPPFLAGS="${CPPFLAGS}"
	saved_LDFLAGS="${LDFLAGS}"
	CPPFLAGS="${CPPFLAGS} ${AM_CPPFLAGS}"
	LDFLAGS="${LDFLAGS} ${AM_LDFLAGS}"
	# HAVE_ELF_C_READ_MMAP
	AC_MSG_CHECKING([whether elf_begin accepts ELF_C_READ_MMAP])
	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <gelf.h>]], [[
	int main () {
	Elf *elf = elf_begin(4, ELF_C_READ_MMAP, 0);
	return 0;
	}
	]])],[
	AC_DEFINE([HAVE_ELF_C_READ_MMAP], [1], [we have read mmap support])
	AC_MSG_RESULT([yes])],[
	AC_MSG_RESULT([no])])

	saved_CFLAGS="${CFLAGS}"
	CFLAGS="${CFLAGS} -Wall -Werror"
	AC_MSG_CHECKING([whether elf_hash takes a char* argument])
	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <libelf.h>]], [[
	(void) elf_hash("name");
	]])],
	[AC_DEFINE([ELF_HASH_TAKES_CHARP], [1],
	[elf_hash() takes char* (as opposed to unsigned char *)])
	AC_MSG_RESULT([yes])],
	[AC_MSG_RESULT([no])])
	CFLAGS="${saved_CFLAGS}"
	CPPFLAGS="${saved_CPPFLAGS}"
	LDFLAGS="${saved_LDFLAGS}"

	AM_CPPFLAGS=" \
	-DSYSCONFDIR="'\"$(sysconfdir)\"'" \
	-DPKGDATADIR="'\"$(pkgdatadir)\"'" \
	${AM_CPPFLAGS} \
	-I\$(top_srcdir)/sysdeps/${HOST_OS}/${HOST_CPU} \
	-I\$(top_srcdir)/sysdeps/${HOST_OS} \
	-I\$(top_srcdir)/sysdeps \
	-I\$(top_srcdir) \
	"

	# Checks for header files.
	AC_CHECK_HEADERS([ \
	fcntl.h \
	limits.h \
	stddef.h \
	stdint.h \
	stdlib.h \
	string.h \
	sys/ioctl.h \
	sys/param.h \
	sys/time.h \
	unistd.h \
	])

	# Checks for typedefs, structures, and compiler characteristics.
	AC_TYPE_UID_T
	AC_C_INLINE
	AC_TYPE_PID_T
	AC_TYPE_SIZE_T
	AC_CHECK_SIZEOF([long])


	# Checks for library functions.
	AC_FUNC_FORK
	AC_CHECK_FUNCS([ \
	alarm \
	atexit \
	gettimeofday \
	memset \
	strchr \
	strdup \
	strerror \
	strsignal \
	strtol \
	strtoul \
	])

	#
	# Define HAVE_OPEN_MEMSTREAM if open_memstream is available. glibc
	# before 2.10, eglibc and uClibc all need _GNU_SOURCE defined for
	# open_memstream to become visible, so check for that as well. If
	# unavailable, require that tmpfile be present. There's no
	# HAVE_TMPFILE, as we plain require that to be present as a fallback.
	#
	AC_CHECK_FUNCS([open_memstream], [],
	[AC_MSG_CHECKING([for open_memstream with _GNU_SOURCE])
	AC_LINK_IFELSE(
	[AC_LANG_PROGRAM([[#define _GNU_SOURCE 1
	#include <stdio.h>]],
	[[char *buf; size_t sz;
	return open_memstream(&buf, &sz) != 0;]])],

	[AC_MSG_RESULT([yes])
	AC_DEFINE([HAVE_OPEN_MEMSTREAM], [1],
	[Define if open_memstream exists.])],

	[AC_MSG_RESULT([no])
	AC_CHECK_FUNC([tmpfile], [],
	[AC_MSG_ERROR(
	[Either open_memstream or tmpfile required.])])])])

	#
	# Define HAVE_GETOPT_LONG if that is available.
	#
	AC_CHECK_HEADER([getopt.h], [AC_CHECK_FUNCS([getopt_long])])

	#
	# Debugging
	#
	AC_MSG_CHECKING([whether to enable debugging])
	AC_ARG_ENABLE(debug,
	AS_HELP_STRING([--enable-debug], [enable debugging @<:@default=no@:>@]),
	[case "$enableval" in
	y \| yes) CONFIG_DEBUG=yes ;;
	*) CONFIG_DEBUG=no ;;
	esac],
	[CONFIG_DEBUG=no])
	AC_MSG_RESULT([${CONFIG_DEBUG}])
	if test "${CONFIG_DEBUG}" = "yes"; then
	AC_DEFINE(DEBUG, 1, [debugging])
	fi

	# Ignore the compiler's warnings at your own risk.
	AM_CFLAGS="${AM_CFLAGS} -Wall -Wsign-compare -Wfloat-equal -Wformat-security"
	AC_ARG_ENABLE([werror],
	AS_HELP_STRING([--disable-werror], [disable use of -Werror]),
	[enable_werror=$enableval], [enable_werror=yes])
	if test x$enable_werror = xyes; then
	AM_CFLAGS="${AM_CFLAGS} -Werror"
	fi

	AC_ARG_ENABLE([valgrind],
	AS_HELP_STRING([--enable-valgrind],[run all tests under valgrind]),
	[use_valgrind=$enableval], [use_valgrind=no])
	if test x$use_valgrind = xyes; then
	AC_CHECK_PROG(HAVE_VALGRIND, valgrind, yes, no)
	if test x$HAVE_VALGRIND = xno; then
	AC_MSG_ERROR([valgrind not found])
	fi
	fi
	AM_CONDITIONAL(USE_VALGRIND, test "$use_valgrind" = yes)

	AC_SUBST(AM_CPPFLAGS)
	AC_SUBST(AM_CFLAGS)
	AC_SUBST(AM_LDFLAGS)
	AC_SUBST(libelf_LD_LIBRARY_PATH)
	AC_SUBST(elfutils_LD_LIBRARY_PATH)
	AC_SUBST(libunwind_LD_LIBRARY_PATH)

	AC_CONFIG_FILES([
	Makefile
	sysdeps/Makefile
	sysdeps/linux-gnu/Makefile
	sysdeps/linux-gnu/aarch64/Makefile
	sysdeps/linux-gnu/alpha/Makefile
	sysdeps/linux-gnu/arm/Makefile
	sysdeps/linux-gnu/cris/Makefile
	sysdeps/linux-gnu/ia64/Makefile
	sysdeps/linux-gnu/m68k/Makefile
	sysdeps/linux-gnu/metag/Makefile
	sysdeps/linux-gnu/mips/Makefile
	sysdeps/linux-gnu/ppc/Makefile
	sysdeps/linux-gnu/s390/Makefile
	sysdeps/linux-gnu/sparc/Makefile
	sysdeps/linux-gnu/x86/Makefile
	testsuite/Makefile
	testsuite/ltrace.main/Makefile
	testsuite/ltrace.minor/Makefile
	testsuite/ltrace.torture/Makefile
	])
	AC_OUTPUT