configure.ac - tmux - Rivoreo Source Code Repositories

 # $Id$

 # Miscellaneous bits.
 AC_INIT(tmux, 2.1)

 AC_CONFIG_AUX_DIR(etc)
 AM_INIT_AUTOMAKE([foreign subdir-objects])

 AC_CANONICAL_HOST

 # When CFLAGS isn't set at this stage and gcc is detected by the macro below,
 # autoconf will automatically use CFLAGS="-O2 -g". Prevent that by using an
 # empty default.
 : ${CFLAGS=""}

 # Set up the compiler in two different ways and say yes we may want to install.
 AC_PROG_CC
 AM_PROG_CC_C_O
 AC_PROG_CPP
 AC_PROG_EGREP
 AC_PROG_INSTALL

 # Default tmux.conf goes in /etc not ${prefix}/etc.
 test "$sysconfdir" = '${prefix}/etc' && sysconfdir=/etc

 # Is this a debug build?
 found_debug=yes
 AC_ARG_ENABLE(
 	debug,
 	AC_HELP_STRING(--enable-debug, create a debug build),
 	found_debug=$enable_debug
 )
 AM_CONDITIONAL(IS_DEBUG, test "x$found_debug" = xyes)

 # Is this a static build?
 AC_ARG_ENABLE(
 	static,
 	AC_HELP_STRING(--enable-static, create a static build),
 	found_static=$enable_static
 )
 if test "x$found_static" = xyes; then
 	LDFLAGS="$LDFLAGS -static"
 fi

 # Is this gcc?
 AM_CONDITIONAL(IS_GCC, test "x$GCC" = xyes)

 # Is this Sun CC?
 AC_EGREP_CPP(
 	yes,
 	[
 		#ifdef __SUNPRO_C
 		yes
 		#endif
 	],
 	found_suncc=yes,
 	found_suncc=no
 )
 AM_CONDITIONAL(IS_SUNCC, test "x$found_suncc" = xyes)

 # Is this glibc?
 AC_MSG_CHECKING(for glibc)
 AC_EGREP_CPP(
 	yes,
 	[
 		#include <features.h>
 		#ifdef __GLIBC__
 		yes
 		#endif
 	],
 	found_glibc=yes,
 	found_glibc=no
 )
 AM_CONDITIONAL(IS_GLIBC, test "x$found_glibc" = xyes)
 AC_MSG_RESULT($found_glibc)

 # Check for various headers. Alternatives included from compat.h.
 AC_CHECK_HEADERS(
 	[ \
 		bitstring.h \
 		curses.h \
 		dirent.h \
 		fcntl.h \
 		inttypes.h \
 		libutil.h \
 		ncurses.h \
 		ndir.h \
 		paths.h \
 		pty.h \
 		stdint.h \
 		sys/dir.h \
 		sys/ndir.h \
 		sys/tree.h \
 		term.h \
 		util.h \
 	]
 )

 # Check for some functions that are replaced or omitted.
 AC_CHECK_FUNCS(
 	[ \
 		bzero \
 		dirfd \
 		flock \
 		setproctitle \
 		sysconf \
 		cfmakeraw \
 	]
 )

 # Look for clock_gettime. Must come before event_init.
 AC_SEARCH_LIBS(clock_gettime, rt)

 # Look for libevent.
 PKG_CHECK_MODULES(
 	LIBEVENT,
 	libevent,
 	[
 		CPPFLAGS="$LIBEVENT_CFLAGS $CPPFLAGS"
 		LIBS="$LIBEVENT_LIBS $LIBS"
 		found_libevent=yes
 	],
 	[
 		AC_SEARCH_LIBS(
 			event_init,
 			[event event-1.4 event2],
 			found_libevent=yes,
 			found_libevent=no
 		)
 	]
 )
 if test "x$found_libevent" = xno; then
 	AC_MSG_ERROR("libevent not found")
 fi

 # Look for curses.
 AC_SEARCH_LIBS(
 	setupterm,
 	[terminfo curses ncurses tinfo],
 	found_curses=yes,
 	found_curses=no
 )
 if test "x$found_curses" = xno; then
 	AC_MSG_ERROR("curses not found")
 fi

 # Look for utempter.
 AC_CHECK_HEADER(utempter.h, have_utempter=yes, have_utempter=no)
 if test "x$have_utempter" = xyes; then
 	AC_DEFINE(HAVE_UTEMPTER)
 	LIBS="$LIBS -lutempter"
 fi

 # Check for b64_ntop.
 AC_MSG_CHECKING(for b64_ntop)
 AC_TRY_LINK(
 	[
 		#include <sys/types.h>
 		#include <netinet/in.h>
 		#include <resolv.h>
 	],
 	[b64_ntop(NULL, 0, NULL, 0);],
 	found_b64_ntop=yes,
 	found_b64_ntop=no
 )
 if test "x$found_b64_ntop" = xno; then
 	AC_MSG_RESULT(no)

 	AC_MSG_CHECKING(for b64_ntop with -lresolv)
 	LIBS="$LIBS -lresolv"
 	AC_TRY_LINK(
 		[
 			#include <sys/types.h>
 			#include <netinet/in.h>
 			#include <resolv.h>
 		],
 		[b64_ntop(NULL, 0, NULL, 0);],
 		found_b64_ntop=yes,
 		found_b64_ntop=no
 	)
 	if test "x$found_b64_ntop" = xno; then
 		AC_MSG_RESULT(no)
 	fi
 fi
 if test "x$found_b64_ntop" = xyes; then
 	AC_DEFINE(HAVE_B64_NTOP)
 	AC_MSG_RESULT(yes)
 fi
 AM_CONDITIONAL(NO_B64_NTOP, [test "x$found_b64_ntop" = xno])

 # Look for networking libraries.
 AC_SEARCH_LIBS(inet_ntoa, nsl)
 AC_SEARCH_LIBS(socket, socket)
 AC_CHECK_LIB(xnet, socket)

 # Check for CMSG_DATA. Some platforms require _XOPEN_SOURCE_EXTENDED (for
 # example see xopen_networking(7) on HP-UX).
 XOPEN_DEFINES=
 AC_MSG_CHECKING(for CMSG_DATA)
 AC_EGREP_CPP(
 	yes,
 	[
 		#include <sys/socket.h>
 		#ifdef CMSG_DATA
 		yes
 		#endif
 	],
 	found_cmsg_data=yes,
 	found_cmsg_data=no
 )
 AC_MSG_RESULT($found_cmsg_data)
 if test "x$found_cmsg_data" = xno; then
 	AC_MSG_CHECKING(if CMSG_DATA needs _XOPEN_SOURCE_EXTENDED)
 	AC_EGREP_CPP(
 		yes,
 		[
 			#define _XOPEN_SOURCE 1
 			#define _XOPEN_SOURCE_EXTENDED 1
 			#include <sys/socket.h>
 			#ifdef CMSG_DATA
 			yes
 			#endif
 		],
 		found_cmsg_data=yes,
 		found_cmsg_data=no
 	)
 	AC_MSG_RESULT($found_cmsg_data)
 	if test "x$found_cmsg_data" = xyes; then
 		XOPEN_DEFINES="-D_XOPEN_SOURCE -D_XOPEN_SOURCE_EXTENDED"
 	else
 		AC_MSG_ERROR("CMSG_DATA not found")
 	fi
 fi
 AC_SUBST(XOPEN_DEFINES)

 # Look for imsg in libutil. compat/imsg.c is linked by Makefile.am if missing.
 AC_SEARCH_LIBS(imsg_init, util, found_imsg_init=yes, found_imsg_init=no)
 if test "x$found_imsg_init" = xyes; then
 	AC_DEFINE(HAVE_IMSG)
 fi
 AM_CONDITIONAL(NO_IMSG, [test "x$found_imsg_init" = xno])

 # Look for forkpty in libutil. compat/forkpty-*.c is linked if not found.
 AC_SEARCH_LIBS(forkpty, util, found_forkpty=yes, found_forkpty=no)
 if test "x$found_forkpty" = xyes; then
 	AC_DEFINE(HAVE_FORKPTY)
 fi
 AM_CONDITIONAL(NO_FORKPTY, [test "x$found_forkpty" = xno])

 # Look for closefrom, compat/closefrom.c used if missing.
 AC_CHECK_FUNC(closefrom, found_closefrom=yes, found_closefrom=no)
 if test "x$found_closefrom" = xyes; then
 	AC_DEFINE(HAVE_CLOSEFROM)
 fi
 AM_CONDITIONAL(NO_CLOSEFROM, [test "x$found_closefrom" = xno])

 # Look for daemon, compat/daemon.c used if missing.
 AC_CHECK_FUNC(daemon, found_daemon=yes, found_daemon=no)
 if test "x$found_daemon" = xyes; then
 	AC_DEFINE(HAVE_DAEMON)
 fi
 AM_CONDITIONAL(NO_DAEMON, [test "x$found_daemon" = xno])

 # Look for setenv, compat/setenv.c used if missing.
 AC_CHECK_FUNC(setenv, found_setenv=yes, found_setenv=no)
 if test "x$found_setenv" = xyes; then
 	AC_DEFINE(HAVE_SETENV)
 fi
 AM_CONDITIONAL(NO_SETENV, [test "x$found_setenv" = xno])

 # Look for strlcpy, compat/strlcpy.c used if missing.
 AC_CHECK_FUNC(strlcpy, found_strlcpy=yes, found_strlcpy=no)
 if test "x$found_strlcpy" = xyes; then
 	AC_DEFINE(HAVE_STRLCPY)
 fi
 AM_CONDITIONAL(NO_STRLCPY, [test "x$found_strlcpy" = xno])

 # Look for strlcat, compat/strlcat.c used if missing.
 AC_CHECK_FUNC(strlcat, found_strlcat=yes, found_strlcat=no)
 if test "x$found_strlcat" = xyes; then
 	AC_DEFINE(HAVE_STRLCAT)
 fi
 AM_CONDITIONAL(NO_STRLCAT, [test "x$found_strlcat" = xno])

 # Look for asprintf, compat/asprintf.c used if missing.
 AC_CHECK_FUNC(asprintf, found_asprintf=yes, found_asprintf=no)
 if test "x$found_asprintf" = xyes; then
 	AC_DEFINE(HAVE_ASPRINTF)
 fi
 AM_CONDITIONAL(NO_ASPRINTF, [test "x$found_asprintf" = xno])

 # Look for fgetln, compat/fgetln.c used if missing.
 AC_CHECK_FUNC(fgetln, found_fgetln=yes, found_fgetln=no)
 if test "x$found_fgetln" = xyes; then
 	AC_DEFINE(HAVE_FGETLN)
 fi
 AM_CONDITIONAL(NO_FGETLN, [test "x$found_fgetln" = xno])

 # Look for fparseln, compat/fparseln.c used if missing.
 AC_CHECK_FUNC(fparseln, found_fparseln=yes, found_fparseln=no)
 if test "x$found_fparseln" = xyes; then
 	AC_DEFINE(HAVE_FPARSELN)
 fi
 AM_CONDITIONAL(NO_FPARSELN, [test "x$found_fparseln" = xno])

 # Look for strcasestr, compat/strcasestr.c used if missing.
 AC_CHECK_FUNC(strcasestr, found_strcasestr=yes, found_strcasestr=no)
 if test "x$found_strcasestr" = xyes; then
 	AC_DEFINE(HAVE_STRCASESTR)
 fi
 AM_CONDITIONAL(NO_STRCASESTR, [test "x$found_strcasestr" = xno])

 # Look for strsep, compat/strsep.c used if missing.
 AC_CHECK_FUNC(strsep, found_strsep=yes, found_strsep=no)
 if test "x$found_strsep" = xyes; then
 	AC_DEFINE(HAVE_STRSEP)
 fi
 AM_CONDITIONAL(NO_STRSEP, [test "x$found_strsep" = xno])

 # Look for strtonum, compat/strtonum.c used if missing.
 AC_CHECK_FUNC(strtonum, found_strtonum=yes, found_strtonum=no)
 if test "x$found_strtonum" = xyes; then
 	AC_DEFINE(HAVE_STRTONUM)
 fi
 AM_CONDITIONAL(NO_STRTONUM, [test "x$found_strtonum" = xno])

 # Look for strnvis, compat/{vis,unvis}.c used if missing.
 AC_CHECK_FUNC(strnvis, found_strnvis=yes, found_strnvis=no)
 if test "x$found_strnvis" = xyes; then
 	AC_MSG_CHECKING(if strnvis is broken)
 	AC_EGREP_HEADER([strnvis\(char \*, const char \*, size_t, int\)],
 			vis.h,
 			AC_MSG_RESULT(no),
 			[found_strnvis=no])
 	if test "x$found_strnvis" = xno; then
 		AC_MSG_RESULT(yes)
 	fi
 fi
 if test "x$found_strnvis" = xyes; then
 	AC_DEFINE(HAVE_VIS)
 fi
 AM_CONDITIONAL(NO_VIS, [test "x$found_strnvis" = xno])

 # Look for cfmakeraw, compat/cfmakeraw.c used if missing.
 AC_CHECK_FUNC(cfmakeraw, found_cfmakeraw=yes, found_cfmakeraw=no)
 if test "x$found_cfmakeraw" = xyes; then
 	AC_DEFINE(HAVE_CFMAKERAW)
 fi
 AM_CONDITIONAL(NO_CFMAKERAW, [test "x$found_cfmakeraw" = xno])

 # Look for openat, compat/openat.c used if missing.
 AC_CHECK_FUNC(openat, found_openat=yes, found_openat=no)
 if test "x$found_openat" = xyes; then
 	AC_DEFINE(HAVE_OPENAT)
 fi
 AM_CONDITIONAL(NO_OPENAT, [test "x$found_openat" = xno])

 # Look for getopt. glibc's getopt does not enforce argument order and the ways
 # of making it do so are stupid, so just use our own instead.
 AC_CHECK_FUNC(getopt, found_getopt=yes, found_getopt=no)
 if test "x$found_getopt" != xno; then
 	AC_CHECK_DECLS(
 		[optarg, optind, optreset],
 		,
 		found_getopt=no,
 		[
 			#include <unistd.h>
 		]
 	)
 	if test "x$found_getopt" != xno; then
 		AC_MSG_CHECKING(if system getopt should be avoided)
 		if test "x$found_glibc" = xyes; then
 			found_getopt=no
 			AC_MSG_RESULT(yes)
 		else
 			AC_MSG_RESULT(no)
 			AC_DEFINE(HAVE_GETOPT)
 		fi
 	fi
 fi
 AM_CONDITIONAL(NO_GETOPT, [test "x$found_getopt" = xno])

 # Check for BSD-style integer types.
 AC_MSG_CHECKING(for BSD-style unsigned types)
 AC_COMPILE_IFELSE([AC_LANG_SOURCE(
 	[
 		#include <sys/types.h>
 		#ifdef HAVE_STDINT_H
 		#include <stdint.h>
 		#else
 		#include <inttypes.h>
 		#endif
 		int main(void)
 		{ u_int8_t u8; u_int16_t u16; u_int32_t u32; u_int64_t u64; }
 	])],
 	[AC_DEFINE(HAVE_BSD_TYPES) AC_MSG_RESULT(yes)],
 	AC_MSG_RESULT(no)
 )

 # Look for a suitable queue.h.
 AC_CHECK_DECL(
 	TAILQ_PREV,
 	found_queue_h=yes,
 	found_queue_h=no,
 	[#include <sys/queue.h>]
 )
 AC_CHECK_DECL(
 	TAILQ_REPLACE,
 	,
 	found_queue_h=no,
 	[#include <sys/queue.h>]
 )
 if test "x$found_queue_h" = xyes; then
 	AC_DEFINE(HAVE_QUEUE_H)
 fi

 # Look for __progname.
 AC_MSG_CHECKING(for __progname)
 AC_LINK_IFELSE([AC_LANG_SOURCE(
 	[
 		#include <stdio.h>
 		#include <stdlib.h>
 		extern char *__progname;
 		int main(void) {
 			const char *cp = __progname;
 			printf("%s\n", cp);
 			exit(0);
 		}
 	])],
 	[AC_DEFINE(HAVE___PROGNAME) AC_MSG_RESULT(yes)],
 	AC_MSG_RESULT(no)
 )

 # Look for fcntl(F_CLOSEM).
 AC_CHECK_DECL(
 	F_CLOSEM,
 	AC_DEFINE(HAVE_FCNTL_CLOSEM),
 	,
 	[#include <fcntl.h>]
 )

 # Look for /proc/$$.
 AC_MSG_CHECKING(for /proc/\$\$)
 if test -d /proc/$$; then
 	AC_DEFINE(HAVE_PROC_PID)
 	AC_MSG_RESULT(yes)
 else
 	AC_MSG_RESULT(no)
 fi

 # Man page defaults to mdoc.
 MANFORMAT=mdoc
 AC_SUBST(MANFORMAT)

 # Figure out the platform for osdep-*.c and forkpty-*.c.
 AC_MSG_CHECKING(platform)
 case "$host_os" in
 	*aix*)
 		AC_MSG_RESULT(aix)
 		PLATFORM=aix
 		;;
 	*darwin*)
 		AC_MSG_RESULT(darwin)
 		AC_DEFINE(BROKEN_CMSG_FIRSTHDR)
 		PLATFORM=darwin
 		;;
 	*dragonfly*)
 		AC_MSG_RESULT(dragonfly)
 		PLATFORM=dragonfly
 		;;
 	*linux*)
 		AC_MSG_RESULT(linux)
 		PLATFORM=linux
 		;;
 	*freebsd*)
 		AC_MSG_RESULT(freebsd)
 		PLATFORM=freebsd
 		;;
 	*netbsd*)
 		AC_MSG_RESULT(netbsd)
 		PLATFORM=netbsd
 		;;
 	*openbsd*)
 		AC_MSG_RESULT(openbsd)
 		PLATFORM=openbsd
 		;;
 	*sunos*)
 		AC_MSG_RESULT(sunos)
 		PLATFORM=sunos
 		;;
 	*solaris*)
 		AC_MSG_RESULT(sunos)
 		PLATFORM=sunos
 		MANFORMAT=man
 		;;
 	*hpux*)
 		AC_MSG_RESULT(hpux)
 		PLATFORM=hpux
 		;;
 	*cygwin*)
 		AC_MSG_RESULT(cygwin)
 		PLATFORM=cygwin
 		;;
 	*)
 		AC_MSG_RESULT(unknown)
 		PLATFORM=unknown
 		;;
 esac
 AC_SUBST(PLATFORM)
 AM_CONDITIONAL(IS_AIX, test "x$PLATFORM" = xaix)
 AM_CONDITIONAL(IS_DARWIN, test "x$PLATFORM" = xdarwin)
 AM_CONDITIONAL(IS_DRAGONFLY, test "x$PLATFORM" = xdragonfly)
 AM_CONDITIONAL(IS_LINUX, test "x$PLATFORM" = xlinux)
 AM_CONDITIONAL(IS_FREEBSD, test "x$PLATFORM" = xfreebsd)
 AM_CONDITIONAL(IS_NETBSD, test "x$PLATFORM" = xnetbsd)
 AM_CONDITIONAL(IS_OPENBSD, test "x$PLATFORM" = xopenbsd)
 AM_CONDITIONAL(IS_SUNOS, test "x$PLATFORM" = xsunos)
 AM_CONDITIONAL(IS_HPUX, test "x$PLATFORM" = xhpux)
 AM_CONDITIONAL(IS_UNKNOWN, test "x$PLATFORM" = xunknown)

 # autoconf should create a Makefile.
 AC_OUTPUT(Makefile)
	# $Id$

	# Miscellaneous bits.
	AC_INIT(tmux, 2.1)

	AC_CONFIG_AUX_DIR(etc)
	AM_INIT_AUTOMAKE([foreign subdir-objects])

	AC_CANONICAL_HOST

	# When CFLAGS isn't set at this stage and gcc is detected by the macro below,
	# autoconf will automatically use CFLAGS="-O2 -g". Prevent that by using an
	# empty default.
	: ${CFLAGS=""}

	# Set up the compiler in two different ways and say yes we may want to install.
	AC_PROG_CC
	AM_PROG_CC_C_O
	AC_PROG_CPP
	AC_PROG_EGREP
	AC_PROG_INSTALL

	# Default tmux.conf goes in /etc not ${prefix}/etc.
	test "$sysconfdir" = '${prefix}/etc' && sysconfdir=/etc

	# Is this a debug build?
	found_debug=yes
	AC_ARG_ENABLE(
	debug,
	AC_HELP_STRING(--enable-debug, create a debug build),
	found_debug=$enable_debug
	)
	AM_CONDITIONAL(IS_DEBUG, test "x$found_debug" = xyes)

	# Is this a static build?
	AC_ARG_ENABLE(
	static,
	AC_HELP_STRING(--enable-static, create a static build),
	found_static=$enable_static
	)
	if test "x$found_static" = xyes; then
	LDFLAGS="$LDFLAGS -static"
	fi

	# Is this gcc?
	AM_CONDITIONAL(IS_GCC, test "x$GCC" = xyes)

	# Is this Sun CC?
	AC_EGREP_CPP(
	yes,
	[
	#ifdef __SUNPRO_C
	yes
	#endif
	],
	found_suncc=yes,
	found_suncc=no
	)
	AM_CONDITIONAL(IS_SUNCC, test "x$found_suncc" = xyes)

	# Is this glibc?
	AC_MSG_CHECKING(for glibc)
	AC_EGREP_CPP(
	yes,
	[
	#include <features.h>
	#ifdef __GLIBC__
	yes
	#endif
	],
	found_glibc=yes,
	found_glibc=no
	)
	AM_CONDITIONAL(IS_GLIBC, test "x$found_glibc" = xyes)
	AC_MSG_RESULT($found_glibc)

	# Check for various headers. Alternatives included from compat.h.
	AC_CHECK_HEADERS(
	[ \
	bitstring.h \
	curses.h \
	dirent.h \
	fcntl.h \
	inttypes.h \
	libutil.h \
	ncurses.h \
	ndir.h \
	paths.h \
	pty.h \
	stdint.h \
	sys/dir.h \
	sys/ndir.h \
	sys/tree.h \
	term.h \
	util.h \
	]
	)

	# Check for some functions that are replaced or omitted.
	AC_CHECK_FUNCS(
	[ \
	bzero \
	dirfd \
	flock \
	setproctitle \
	sysconf \
	cfmakeraw \
	]
	)

	# Look for clock_gettime. Must come before event_init.
	AC_SEARCH_LIBS(clock_gettime, rt)

	# Look for libevent.
	PKG_CHECK_MODULES(
	LIBEVENT,
	libevent,
	[
	CPPFLAGS="$LIBEVENT_CFLAGS $CPPFLAGS"
	LIBS="$LIBEVENT_LIBS $LIBS"
	found_libevent=yes
	],
	[
	AC_SEARCH_LIBS(
	event_init,
	[event event-1.4 event2],
	found_libevent=yes,
	found_libevent=no
	)
	]
	)
	if test "x$found_libevent" = xno; then
	AC_MSG_ERROR("libevent not found")
	fi

	# Look for curses.
	AC_SEARCH_LIBS(
	setupterm,
	[terminfo curses ncurses tinfo],
	found_curses=yes,
	found_curses=no
	)
	if test "x$found_curses" = xno; then
	AC_MSG_ERROR("curses not found")
	fi

	# Look for utempter.
	AC_CHECK_HEADER(utempter.h, have_utempter=yes, have_utempter=no)
	if test "x$have_utempter" = xyes; then
	AC_DEFINE(HAVE_UTEMPTER)
	LIBS="$LIBS -lutempter"
	fi

	# Check for b64_ntop.
	AC_MSG_CHECKING(for b64_ntop)
	AC_TRY_LINK(
	[
	#include <sys/types.h>
	#include <netinet/in.h>
	#include <resolv.h>
	],
	[b64_ntop(NULL, 0, NULL, 0);],
	found_b64_ntop=yes,
	found_b64_ntop=no
	)
	if test "x$found_b64_ntop" = xno; then
	AC_MSG_RESULT(no)

	AC_MSG_CHECKING(for b64_ntop with -lresolv)
	LIBS="$LIBS -lresolv"
	AC_TRY_LINK(
	[
	#include <sys/types.h>
	#include <netinet/in.h>
	#include <resolv.h>
	],
	[b64_ntop(NULL, 0, NULL, 0);],
	found_b64_ntop=yes,
	found_b64_ntop=no
	)
	if test "x$found_b64_ntop" = xno; then
	AC_MSG_RESULT(no)
	fi
	fi
	if test "x$found_b64_ntop" = xyes; then
	AC_DEFINE(HAVE_B64_NTOP)
	AC_MSG_RESULT(yes)
	fi
	AM_CONDITIONAL(NO_B64_NTOP, [test "x$found_b64_ntop" = xno])

	# Look for networking libraries.
	AC_SEARCH_LIBS(inet_ntoa, nsl)
	AC_SEARCH_LIBS(socket, socket)
	AC_CHECK_LIB(xnet, socket)

	# Check for CMSG_DATA. Some platforms require _XOPEN_SOURCE_EXTENDED (for
	# example see xopen_networking(7) on HP-UX).
	XOPEN_DEFINES=
	AC_MSG_CHECKING(for CMSG_DATA)
	AC_EGREP_CPP(
	yes,
	[
	#include <sys/socket.h>
	#ifdef CMSG_DATA
	yes
	#endif
	],
	found_cmsg_data=yes,
	found_cmsg_data=no
	)
	AC_MSG_RESULT($found_cmsg_data)
	if test "x$found_cmsg_data" = xno; then
	AC_MSG_CHECKING(if CMSG_DATA needs _XOPEN_SOURCE_EXTENDED)
	AC_EGREP_CPP(
	yes,
	[
	#define _XOPEN_SOURCE 1
	#define _XOPEN_SOURCE_EXTENDED 1
	#include <sys/socket.h>
	#ifdef CMSG_DATA
	yes
	#endif
	],
	found_cmsg_data=yes,
	found_cmsg_data=no
	)
	AC_MSG_RESULT($found_cmsg_data)
	if test "x$found_cmsg_data" = xyes; then
	XOPEN_DEFINES="-D_XOPEN_SOURCE -D_XOPEN_SOURCE_EXTENDED"
	else
	AC_MSG_ERROR("CMSG_DATA not found")
	fi
	fi
	AC_SUBST(XOPEN_DEFINES)

	# Look for imsg in libutil. compat/imsg.c is linked by Makefile.am if missing.
	AC_SEARCH_LIBS(imsg_init, util, found_imsg_init=yes, found_imsg_init=no)
	if test "x$found_imsg_init" = xyes; then
	AC_DEFINE(HAVE_IMSG)
	fi
	AM_CONDITIONAL(NO_IMSG, [test "x$found_imsg_init" = xno])

	# Look for forkpty in libutil. compat/forkpty-*.c is linked if not found.
	AC_SEARCH_LIBS(forkpty, util, found_forkpty=yes, found_forkpty=no)
	if test "x$found_forkpty" = xyes; then
	AC_DEFINE(HAVE_FORKPTY)
	fi
	AM_CONDITIONAL(NO_FORKPTY, [test "x$found_forkpty" = xno])

	# Look for closefrom, compat/closefrom.c used if missing.
	AC_CHECK_FUNC(closefrom, found_closefrom=yes, found_closefrom=no)
	if test "x$found_closefrom" = xyes; then
	AC_DEFINE(HAVE_CLOSEFROM)
	fi
	AM_CONDITIONAL(NO_CLOSEFROM, [test "x$found_closefrom" = xno])

	# Look for daemon, compat/daemon.c used if missing.
	AC_CHECK_FUNC(daemon, found_daemon=yes, found_daemon=no)
	if test "x$found_daemon" = xyes; then
	AC_DEFINE(HAVE_DAEMON)
	fi
	AM_CONDITIONAL(NO_DAEMON, [test "x$found_daemon" = xno])

	# Look for setenv, compat/setenv.c used if missing.
	AC_CHECK_FUNC(setenv, found_setenv=yes, found_setenv=no)
	if test "x$found_setenv" = xyes; then
	AC_DEFINE(HAVE_SETENV)
	fi
	AM_CONDITIONAL(NO_SETENV, [test "x$found_setenv" = xno])

	# Look for strlcpy, compat/strlcpy.c used if missing.
	AC_CHECK_FUNC(strlcpy, found_strlcpy=yes, found_strlcpy=no)
	if test "x$found_strlcpy" = xyes; then
	AC_DEFINE(HAVE_STRLCPY)
	fi
	AM_CONDITIONAL(NO_STRLCPY, [test "x$found_strlcpy" = xno])

	# Look for strlcat, compat/strlcat.c used if missing.
	AC_CHECK_FUNC(strlcat, found_strlcat=yes, found_strlcat=no)
	if test "x$found_strlcat" = xyes; then
	AC_DEFINE(HAVE_STRLCAT)
	fi
	AM_CONDITIONAL(NO_STRLCAT, [test "x$found_strlcat" = xno])

	# Look for asprintf, compat/asprintf.c used if missing.
	AC_CHECK_FUNC(asprintf, found_asprintf=yes, found_asprintf=no)
	if test "x$found_asprintf" = xyes; then
	AC_DEFINE(HAVE_ASPRINTF)
	fi
	AM_CONDITIONAL(NO_ASPRINTF, [test "x$found_asprintf" = xno])

	# Look for fgetln, compat/fgetln.c used if missing.
	AC_CHECK_FUNC(fgetln, found_fgetln=yes, found_fgetln=no)
	if test "x$found_fgetln" = xyes; then
	AC_DEFINE(HAVE_FGETLN)
	fi
	AM_CONDITIONAL(NO_FGETLN, [test "x$found_fgetln" = xno])

	# Look for fparseln, compat/fparseln.c used if missing.
	AC_CHECK_FUNC(fparseln, found_fparseln=yes, found_fparseln=no)
	if test "x$found_fparseln" = xyes; then
	AC_DEFINE(HAVE_FPARSELN)
	fi
	AM_CONDITIONAL(NO_FPARSELN, [test "x$found_fparseln" = xno])

	# Look for strcasestr, compat/strcasestr.c used if missing.
	AC_CHECK_FUNC(strcasestr, found_strcasestr=yes, found_strcasestr=no)
	if test "x$found_strcasestr" = xyes; then
	AC_DEFINE(HAVE_STRCASESTR)
	fi
	AM_CONDITIONAL(NO_STRCASESTR, [test "x$found_strcasestr" = xno])

	# Look for strsep, compat/strsep.c used if missing.
	AC_CHECK_FUNC(strsep, found_strsep=yes, found_strsep=no)
	if test "x$found_strsep" = xyes; then
	AC_DEFINE(HAVE_STRSEP)
	fi
	AM_CONDITIONAL(NO_STRSEP, [test "x$found_strsep" = xno])

	# Look for strtonum, compat/strtonum.c used if missing.
	AC_CHECK_FUNC(strtonum, found_strtonum=yes, found_strtonum=no)
	if test "x$found_strtonum" = xyes; then
	AC_DEFINE(HAVE_STRTONUM)
	fi
	AM_CONDITIONAL(NO_STRTONUM, [test "x$found_strtonum" = xno])

	# Look for strnvis, compat/{vis,unvis}.c used if missing.
	AC_CHECK_FUNC(strnvis, found_strnvis=yes, found_strnvis=no)
	if test "x$found_strnvis" = xyes; then
	AC_MSG_CHECKING(if strnvis is broken)
	AC_EGREP_HEADER([strnvis\(char \, const char \, size_t, int\)],
	vis.h,
	AC_MSG_RESULT(no),
	[found_strnvis=no])
	if test "x$found_strnvis" = xno; then
	AC_MSG_RESULT(yes)
	fi
	fi
	if test "x$found_strnvis" = xyes; then
	AC_DEFINE(HAVE_VIS)
	fi
	AM_CONDITIONAL(NO_VIS, [test "x$found_strnvis" = xno])

	# Look for cfmakeraw, compat/cfmakeraw.c used if missing.
	AC_CHECK_FUNC(cfmakeraw, found_cfmakeraw=yes, found_cfmakeraw=no)
	if test "x$found_cfmakeraw" = xyes; then
	AC_DEFINE(HAVE_CFMAKERAW)
	fi
	AM_CONDITIONAL(NO_CFMAKERAW, [test "x$found_cfmakeraw" = xno])

	# Look for openat, compat/openat.c used if missing.
	AC_CHECK_FUNC(openat, found_openat=yes, found_openat=no)
	if test "x$found_openat" = xyes; then
	AC_DEFINE(HAVE_OPENAT)
	fi
	AM_CONDITIONAL(NO_OPENAT, [test "x$found_openat" = xno])

	# Look for getopt. glibc's getopt does not enforce argument order and the ways
	# of making it do so are stupid, so just use our own instead.
	AC_CHECK_FUNC(getopt, found_getopt=yes, found_getopt=no)
	if test "x$found_getopt" != xno; then
	AC_CHECK_DECLS(
	[optarg, optind, optreset],
	,
	found_getopt=no,
	[
	#include <unistd.h>
	]
	)
	if test "x$found_getopt" != xno; then
	AC_MSG_CHECKING(if system getopt should be avoided)
	if test "x$found_glibc" = xyes; then
	found_getopt=no
	AC_MSG_RESULT(yes)
	else
	AC_MSG_RESULT(no)
	AC_DEFINE(HAVE_GETOPT)
	fi
	fi
	fi
	AM_CONDITIONAL(NO_GETOPT, [test "x$found_getopt" = xno])

	# Check for BSD-style integer types.
	AC_MSG_CHECKING(for BSD-style unsigned types)
	AC_COMPILE_IFELSE([AC_LANG_SOURCE(
	[
	#include <sys/types.h>
	#ifdef HAVE_STDINT_H
	#include <stdint.h>
	#else
	#include <inttypes.h>
	#endif
	int main(void)
	{ u_int8_t u8; u_int16_t u16; u_int32_t u32; u_int64_t u64; }
	])],
	[AC_DEFINE(HAVE_BSD_TYPES) AC_MSG_RESULT(yes)],
	AC_MSG_RESULT(no)
	)

	# Look for a suitable queue.h.
	AC_CHECK_DECL(
	TAILQ_PREV,
	found_queue_h=yes,
	found_queue_h=no,
	[#include <sys/queue.h>]
	)
	AC_CHECK_DECL(
	TAILQ_REPLACE,
	,
	found_queue_h=no,
	[#include <sys/queue.h>]
	)
	if test "x$found_queue_h" = xyes; then
	AC_DEFINE(HAVE_QUEUE_H)
	fi

	# Look for __progname.
	AC_MSG_CHECKING(for __progname)
	AC_LINK_IFELSE([AC_LANG_SOURCE(
	[
	#include <stdio.h>
	#include <stdlib.h>
	extern char *__progname;
	int main(void) {
	const char *cp = __progname;
	printf("%s\n", cp);
	exit(0);
	}
	])],
	[AC_DEFINE(HAVE___PROGNAME) AC_MSG_RESULT(yes)],
	AC_MSG_RESULT(no)
	)

	# Look for fcntl(F_CLOSEM).
	AC_CHECK_DECL(
	F_CLOSEM,
	AC_DEFINE(HAVE_FCNTL_CLOSEM),
	,
	[#include <fcntl.h>]
	)

	# Look for /proc/$$.
	AC_MSG_CHECKING(for /proc/\$\$)
	if test -d /proc/$$; then
	AC_DEFINE(HAVE_PROC_PID)
	AC_MSG_RESULT(yes)
	else
	AC_MSG_RESULT(no)
	fi

	# Man page defaults to mdoc.
	MANFORMAT=mdoc
	AC_SUBST(MANFORMAT)

	# Figure out the platform for osdep-.c and forkpty-.c.
	AC_MSG_CHECKING(platform)
	case "$host_os" in
	aix)
	AC_MSG_RESULT(aix)
	PLATFORM=aix
	;;
	darwin)
	AC_MSG_RESULT(darwin)
	AC_DEFINE(BROKEN_CMSG_FIRSTHDR)
	PLATFORM=darwin
	;;
	dragonfly)
	AC_MSG_RESULT(dragonfly)
	PLATFORM=dragonfly
	;;
	linux)
	AC_MSG_RESULT(linux)
	PLATFORM=linux
	;;
	freebsd)
	AC_MSG_RESULT(freebsd)
	PLATFORM=freebsd
	;;
	netbsd)
	AC_MSG_RESULT(netbsd)
	PLATFORM=netbsd
	;;
	openbsd)
	AC_MSG_RESULT(openbsd)
	PLATFORM=openbsd
	;;
	sunos)
	AC_MSG_RESULT(sunos)
	PLATFORM=sunos
	;;
	solaris)
	AC_MSG_RESULT(sunos)
	PLATFORM=sunos
	MANFORMAT=man
	;;
	hpux)
	AC_MSG_RESULT(hpux)
	PLATFORM=hpux
	;;
	cygwin)
	AC_MSG_RESULT(cygwin)
	PLATFORM=cygwin
	;;
	*)
	AC_MSG_RESULT(unknown)
	PLATFORM=unknown
	;;
	esac
	AC_SUBST(PLATFORM)
	AM_CONDITIONAL(IS_AIX, test "x$PLATFORM" = xaix)
	AM_CONDITIONAL(IS_DARWIN, test "x$PLATFORM" = xdarwin)
	AM_CONDITIONAL(IS_DRAGONFLY, test "x$PLATFORM" = xdragonfly)
	AM_CONDITIONAL(IS_LINUX, test "x$PLATFORM" = xlinux)
	AM_CONDITIONAL(IS_FREEBSD, test "x$PLATFORM" = xfreebsd)
	AM_CONDITIONAL(IS_NETBSD, test "x$PLATFORM" = xnetbsd)
	AM_CONDITIONAL(IS_OPENBSD, test "x$PLATFORM" = xopenbsd)
	AM_CONDITIONAL(IS_SUNOS, test "x$PLATFORM" = xsunos)
	AM_CONDITIONAL(IS_HPUX, test "x$PLATFORM" = xhpux)
	AM_CONDITIONAL(IS_UNKNOWN, test "x$PLATFORM" = xunknown)

	# autoconf should create a Makefile.
	AC_OUTPUT(Makefile)