Adding upstream version 3.3a.upstream/3.3a

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 929 insertions, 0 deletions

diff --git a/configure.ac b/configure.ac
new file mode 100644
index 0000000..2b8b3b1
--- /dev/null
+++ b/configure.ac
@@ -0,0 +1,929 @@
+# configure.ac
+
+AC_INIT([tmux], 3.3a)
+AC_PREREQ([2.60])
+
+AC_CONFIG_AUX_DIR(etc)
+AC_CONFIG_LIBOBJ_DIR(compat)
+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.
+: ${CFLAGS=""}
+
+# Save user CPPFLAGS, CFLAGS and LDFLAGS. We need to change them because
+# AC_CHECK_HEADER doesn't give us any other way to update the include
+# paths. But for Makefile.am we want to use AM_CPPFLAGS and friends.
+SAVED_CFLAGS="$CFLAGS"
+SAVED_CPPFLAGS="$CPPFLAGS"
+SAVED_LDFLAGS="$LDFLAGS"
+
+# Is this oss-fuzz build?
+AC_ARG_ENABLE(
+	fuzzing,
+	AS_HELP_STRING(--enable-fuzzing, build fuzzers)
+)
+AC_ARG_VAR(
+	FUZZING_LIBS,
+	AS_HELP_STRING(libraries to link fuzzing targets with)
+)
+
+# Set up convenient fuzzing defaults before initializing compiler.
+if test "x$enable_fuzzing" = xyes; then
+	AC_DEFINE(NEED_FUZZING)
+	test "x$CC" = x && CC=clang
+	test "x$FUZZING_LIBS" = x && \
+		FUZZING_LIBS="-fsanitize=fuzzer"
+	test "x$SAVED_CFLAGS" = x && \
+		AM_CFLAGS="-g -fsanitize=fuzzer-no-link,address"
+fi
+
+# 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_CC_C99
+AC_PROG_CPP
+AC_PROG_EGREP
+AC_PROG_INSTALL
+AC_PROG_YACC
+PKG_PROG_PKG_CONFIG
+AC_USE_SYSTEM_EXTENSIONS
+
+# Default tmux.conf goes in /etc not ${prefix}/etc.
+test "$sysconfdir" = '${prefix}/etc' && sysconfdir=/etc
+
+# Is this --enable-debug?
+case "x$VERSION" in xnext*) enable_debug=yes;; esac
+AC_ARG_ENABLE(
+	debug,
+	AS_HELP_STRING(--enable-debug, enable debug build flags),
+)
+AM_CONDITIONAL(IS_DEBUG, test "x$enable_debug" = xyes)
+
+# Is this a static build?
+AC_ARG_ENABLE(
+	static,
+	AS_HELP_STRING(--enable-static, create a static build)
+)
+if test "x$enable_static" = xyes; then
+	case "$host_os" in
+		*darwin*)
+			AC_MSG_ERROR([static linking is not supported on macOS])
+			;;
+	esac
+	test "x$PKG_CONFIG" != x && PKG_CONFIG="$PKG_CONFIG --static"
+	AM_LDFLAGS="-static $AM_LDFLAGS"
+	LDFLAGS="$AM_LDFLAGS $SAVED_LDFLAGS"
+fi
+
+# Allow default TERM to be set.
+AC_ARG_WITH(
+	TERM,
+	AS_HELP_STRING(--with-TERM, set default TERM),
+	[DEFAULT_TERM=$withval],
+	[DEFAULT_TERM=]
+)
+case "x$DEFAULT_TERM" in
+	xscreen*|xtmux*|x)
+	;;
+	*)
+		AC_MSG_ERROR("unsuitable TERM (must be screen* or tmux*)")
+	;;
+esac
+
+# Do we need fuzzers?
+AM_CONDITIONAL(NEED_FUZZING, test "x$enable_fuzzing" = xyes)
+
+# Is this gcc?
+AM_CONDITIONAL(IS_GCC, test "x$GCC" = xyes -a "x$enable_fuzzing" != 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)
+
+# Check for various headers. Alternatives included from compat.h.
+AC_CHECK_HEADERS([ \
+	bitstring.h \
+	dirent.h \
+	fcntl.h \
+	inttypes.h \
+	libproc.h \
+	libutil.h \
+	ndir.h \
+	paths.h \
+	pty.h \
+	stdint.h \
+	sys/dir.h \
+	sys/ndir.h \
+	sys/tree.h \
+	ucred.h \
+	util.h \
+])
+
+# Look for sys_signame.
+AC_SEARCH_LIBS(sys_signame, , AC_DEFINE(HAVE_SYS_SIGNAME))
+
+# Look for fmod.
+AC_CHECK_LIB(m, fmod)
+
+# Look for library needed for flock.
+AC_SEARCH_LIBS(flock, bsd)
+
+# Check for functions that are replaced or omitted.
+AC_CHECK_FUNCS([ \
+	dirfd \
+	flock \
+	prctl \
+	proc_pidinfo \
+	getpeerucred \
+	sysconf \
+])
+
+# Check for functions with a compatibility implementation.
+AC_REPLACE_FUNCS([ \
+	asprintf \
+	cfmakeraw \
+	clock_gettime \
+	closefrom \
+	explicit_bzero \
+	fgetln \
+	freezero \
+	getdtablecount \
+	getdtablesize \
+	getpeereid \
+	getline \
+	getprogname \
+	memmem \
+	setenv \
+	setproctitle \
+	strcasestr \
+	strlcat \
+	strlcpy \
+	strndup \
+	strsep \
+])
+AC_FUNC_STRNLEN
+
+# Check if strtonum works.
+AC_MSG_CHECKING([for working strtonum])
+AC_RUN_IFELSE([AC_LANG_PROGRAM(
+		[#include <stdlib.h>],
+		[return (strtonum("0", 0, 1, NULL) == 0 ? 0 : 1);]
+	)],
+	[AC_DEFINE(HAVE_STRTONUM) AC_MSG_RESULT(yes)],
+	[AC_LIBOBJ(strtonum) AC_MSG_RESULT(no)],
+	[AC_LIBOBJ(strtonum) AC_MSG_RESULT(no)]
+)
+
+# Clang sanitizers wrap reallocarray even if it isn't available on the target
+# system. When compiled it always returns NULL and crashes the program. To
+# detect this we need a more complicated test.
+AC_MSG_CHECKING([for working reallocarray])
+AC_RUN_IFELSE([AC_LANG_PROGRAM(
+		[#include <stdlib.h>],
+		[return (reallocarray(NULL, 1, 1) == NULL);]
+	)],
+	AC_MSG_RESULT(yes),
+	[AC_LIBOBJ(reallocarray) AC_MSG_RESULT([no])],
+	[AC_LIBOBJ(reallocarray) AC_MSG_RESULT([no])]
+)
+AC_MSG_CHECKING([for working recallocarray])
+AC_RUN_IFELSE([AC_LANG_PROGRAM(
+		[#include <stdlib.h>],
+		[return (recallocarray(NULL, 1, 1, 1) == NULL);]
+	)],
+	AC_MSG_RESULT(yes),
+	[AC_LIBOBJ(recallocarray) AC_MSG_RESULT([no])],
+	[AC_LIBOBJ(recallocarray) AC_MSG_RESULT([no])]
+)
+
+# Look for clock_gettime. Must come before event_init.
+AC_SEARCH_LIBS(clock_gettime, rt)
+
+# Always use our getopt because 1) glibc's doesn't enforce argument order 2)
+# musl does not set optarg to NULL for flags without arguments (although it is
+# not required to, but it is helpful) 3) there are probably other weird
+# implementations.
+AC_LIBOBJ(getopt)
+
+# Look for libevent. Try libevent_core or libevent with pkg-config first then
+# look for the library.
+PKG_CHECK_MODULES(
+	LIBEVENT_CORE,
+	[libevent_core >= 2],
+	[
+		AM_CPPFLAGS="$LIBEVENT_CORE_CFLAGS $AM_CPPFLAGS"
+		CPPFLAGS="$AM_CPPFLAGS $SAVED_CPPFLAGS"
+		LIBS="$LIBEVENT_CORE_LIBS $LIBS"
+		found_libevent=yes
+	],
+	found_libevent=no
+)
+if test x$found_libevent = xno; then
+	PKG_CHECK_MODULES(
+		LIBEVENT,
+		[libevent >= 2],
+		[
+			AM_CPPFLAGS="$LIBEVENT_CFLAGS $AM_CPPFLAGS"
+			CPPFLAGS="$AM_CPPFLAGS $SAVED_CPPFLAGS"
+			LIBS="$LIBEVENT_LIBS $LIBS"
+			found_libevent=yes
+		],
+		found_libevent=no
+	)
+fi
+if test x$found_libevent = xno; then
+	AC_SEARCH_LIBS(
+		event_init,
+		[event_core event event-1.4],
+		found_libevent=yes,
+		found_libevent=no
+	)
+fi
+AC_CHECK_HEADER(
+	event2/event.h,
+	AC_DEFINE(HAVE_EVENT2_EVENT_H),
+	[
+		AC_CHECK_HEADER(
+			event.h,
+			AC_DEFINE(HAVE_EVENT_H),
+			found_libevent=no
+		)
+	]
+)
+if test "x$found_libevent" = xno; then
+	AC_MSG_ERROR("libevent not found")
+fi
+
+# Look for ncurses or curses. Try pkg-config first then directly for the
+# library.
+PKG_CHECK_MODULES(
+	LIBTINFO,
+	tinfo,
+	[
+		AM_CPPFLAGS="$LIBTINFO_CFLAGS $AM_CPPFLAGS"
+		CPPFLAGS="$LIBTINFO_CFLAGS $SAVED_CPPFLAGS"
+		LIBS="$LIBTINFO_LIBS $LIBS"
+		found_ncurses=yes
+	],
+	found_ncurses=no
+)
+if test "x$found_ncurses" = xno; then
+	PKG_CHECK_MODULES(
+		LIBNCURSES,
+		ncurses,
+		[
+			AM_CPPFLAGS="$LIBNCURSES_CFLAGS $AM_CPPFLAGS"
+			CPPFLAGS="$LIBNCURSES_CFLAGS $SAVED_CPPFLAGS"
+			LIBS="$LIBNCURSES_LIBS $LIBS"
+			found_ncurses=yes
+		],
+		found_ncurses=no
+	)
+fi
+if test "x$found_ncurses" = xno; then
+	PKG_CHECK_MODULES(
+		LIBNCURSESW,
+		ncursesw,
+		[
+			AM_CPPFLAGS="$LIBNCURSESW_CFLAGS $AM_CPPFLAGS"
+			CPPFLAGS="$LIBNCURSESW_CFLAGS $SAVED_CPPFLAGS"
+			LIBS="$LIBNCURSESW_LIBS $LIBS"
+			found_ncurses=yes
+		],
+		found_ncurses=no
+	)
+fi
+if test "x$found_ncurses" = xno; then
+	AC_SEARCH_LIBS(
+		setupterm,
+		[tinfo ncurses ncursesw],
+		found_ncurses=yes,
+		found_ncurses=no
+	)
+	if test "x$found_ncurses" = xyes; then
+		AC_CHECK_HEADER(
+			ncurses.h,
+			LIBS="$LIBS -lncurses",
+			found_ncurses=no
+		)
+	fi
+fi
+if test "x$found_ncurses" = xyes; then
+	CPPFLAGS="$CPPFLAGS -DHAVE_NCURSES_H"
+	AC_DEFINE(HAVE_NCURSES_H)
+else
+	AC_CHECK_LIB(
+		curses,
+		setupterm,
+		found_curses=yes,
+		found_curses=no
+	)
+	AC_CHECK_HEADER(
+		curses.h,
+		,
+		found_curses=no
+	)
+	if test "x$found_curses" = xyes; then
+		LIBS="$LIBS -lcurses"
+		CPPFLAGS="$CPPFLAGS -DHAVE_CURSES_H"
+		AC_DEFINE(HAVE_CURSES_H)
+	else
+		AC_MSG_ERROR("curses not found")
+	fi
+fi
+
+# Look for utempter.
+AC_ARG_ENABLE(
+	utempter,
+	AS_HELP_STRING(--enable-utempter, use utempter if it is installed)
+)
+if test "x$enable_utempter" = xyes; then
+	AC_CHECK_HEADER(utempter.h, enable_utempter=yes, enable_utempter=no)
+	if test "x$enable_utempter" = xyes; then
+		AC_SEARCH_LIBS(
+			utempter_add_record,
+			utempter,
+			enable_utempter=yes,
+			enable_utempter=no
+		)
+	fi
+	if test "x$enable_utempter" = xyes; then
+		AC_DEFINE(HAVE_UTEMPTER)
+	else
+		AC_MSG_ERROR("utempter not found")
+	fi
+fi
+
+# Look for utf8proc.
+AC_ARG_ENABLE(
+	utf8proc,
+	AS_HELP_STRING(--enable-utf8proc, use utf8proc if it is installed)
+)
+if test "x$enable_utf8proc" = xyes; then
+	AC_CHECK_HEADER(utf8proc.h, enable_utf8proc=yes, enable_utf8proc=no)
+	if test "x$enable_utf8proc" = xyes; then
+		AC_SEARCH_LIBS(
+			utf8proc_charwidth,
+			utf8proc,
+			enable_utf8proc=yes,
+			enable_utf8proc=no
+		)
+	fi
+	if test "x$enable_utf8proc" = xyes; then
+		AC_DEFINE(HAVE_UTF8PROC)
+	else
+		AC_MSG_ERROR("utf8proc not found")
+	fi
+fi
+AM_CONDITIONAL(HAVE_UTF8PROC, [test "x$enable_utf8proc" = xyes])
+
+# Check for systemd support.
+AC_ARG_ENABLE(
+	systemd,
+	AS_HELP_STRING(--enable-systemd, enable systemd integration)
+)
+if test x"$enable_systemd" = xyes; then
+	PKG_CHECK_MODULES(
+		SYSTEMD,
+		libsystemd,
+		[
+			AM_CPPFLAGS="$SYSTEMD_CFLAGS $AM_CPPFLAGS"
+			CPPFLAGS="$AM_CPPFLAGS $SAVED_CPPFLAGS"
+			LIBS="$SYSTEMD_LIBS $LIBS"
+			found_systemd=yes
+		],
+		found_systemd=no
+	)
+	if test "x$found_systemd" = xyes; then
+		AC_DEFINE(HAVE_SYSTEMD)
+	else
+		AC_MSG_ERROR("systemd not found")
+	fi
+fi
+AM_CONDITIONAL(HAVE_SYSTEMD, [test "x$found_systemd" = xyes])
+
+# Check for b64_ntop. If we have b64_ntop, we assume b64_pton as well.
+AC_MSG_CHECKING(for b64_ntop)
+	AC_LINK_IFELSE([AC_LANG_PROGRAM(
+	[
+		#include <sys/types.h>
+		#include <netinet/in.h>
+		#include <resolv.h>
+	],
+	[
+		b64_ntop(NULL, 0, NULL, 0);
+	])],
+	found_b64_ntop=yes,
+	found_b64_ntop=no
+)
+AC_MSG_RESULT($found_b64_ntop)
+OLD_LIBS="$LIBS"
+if test "x$found_b64_ntop" = xno; then
+	AC_MSG_CHECKING(for b64_ntop with -lresolv)
+	LIBS="$OLD_LIBS -lresolv"
+	AC_LINK_IFELSE([AC_LANG_PROGRAM(
+		[
+			#include <sys/types.h>
+			#include <netinet/in.h>
+			#include <resolv.h>
+		],
+		[
+			b64_ntop(NULL, 0, NULL, 0);
+		])],
+		found_b64_ntop=yes,
+		found_b64_ntop=no
+	)
+	AC_MSG_RESULT($found_b64_ntop)
+fi
+if test "x$found_b64_ntop" = xno; then
+	AC_MSG_CHECKING(for b64_ntop with -lnetwork)
+	LIBS="$OLD_LIBS -lnetwork"
+	AC_LINK_IFELSE([AC_LANG_PROGRAM(
+		[
+			#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
+	)
+	AC_MSG_RESULT($found_b64_ntop)
+fi
+if test "x$found_b64_ntop" = xyes; then
+	AC_DEFINE(HAVE_B64_NTOP)
+else
+	LIBS="$OLD_LIBS"
+	AC_LIBOBJ(base64)
+fi
+
+# Look for networking libraries.
+AC_SEARCH_LIBS(inet_ntoa, nsl)
+AC_SEARCH_LIBS(socket, socket)
+AC_CHECK_LIB(xnet, socket)
+
+# Check if using glibc and have malloc_trim(3). The glibc free(3) is pretty bad
+# about returning memory to the kernel unless the application tells it when to
+# with malloc_trim(3).
+AC_MSG_CHECKING(if free doesn't work very well)
+AC_LINK_IFELSE([AC_LANG_SOURCE(
+	[
+		#include <stdlib.h>
+		#ifdef __GLIBC__
+		#include <malloc.h>
+		int main(void) {
+			malloc_trim (0);
+			exit(0);
+		}
+		#else
+		no
+		#endif
+	])],
+	found_malloc_trim=yes,
+	found_malloc_trim=no
+)
+AC_MSG_RESULT($found_malloc_trim)
+if test "x$found_malloc_trim" = xyes; then
+	AC_DEFINE(HAVE_MALLOC_TRIM)
+fi
+
+# Check for CMSG_DATA. On some platforms like HP-UX this requires UNIX 95
+# (_XOPEN_SOURCE and _XOPEN_SOURCE_EXTENDED) (see xopen_networking(7)). On
+# others, UNIX 03 (_XOPEN_SOURCE 600, see standards(7) on Solaris).
+XOPEN_DEFINES=
+AC_MSG_CHECKING(for CMSG_DATA)
+AC_EGREP_CPP(
+	yes,
+	[
+		#include <sys/socket.h>
+		#ifdef CMSG_DATA
+		yes
+		#endif
+	],
+	found_cmsg_data=yes,
+	found_cmsg_data=no
+)
+AC_MSG_RESULT($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$found_cmsg_data" = xyes; then
+		XOPEN_DEFINES="-D_XOPEN_SOURCE -D_XOPEN_SOURCE_EXTENDED"
+	fi
+fi
+if test "x$found_cmsg_data" = xno; then
+	AC_MSG_CHECKING(if CMSG_DATA needs _XOPEN_SOURCE 600)
+	AC_EGREP_CPP(
+		yes,
+		[
+			#define _XOPEN_SOURCE 600
+			#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=600"
+	else
+		AC_MSG_ERROR("CMSG_DATA not found")
+	fi
+fi
+AC_SUBST(XOPEN_DEFINES)
+
+# Look for err and friends in err.h.
+AC_CHECK_FUNC(err, found_err_h=yes, found_err_h=no)
+AC_CHECK_FUNC(errx, , found_err_h=no)
+AC_CHECK_FUNC(warn, , found_err_h=no)
+AC_CHECK_FUNC(warnx, , found_err_h=no)
+if test "x$found_err_h" = xyes; then
+	AC_CHECK_HEADER(err.h, , found_err_h=no)
+else
+	AC_LIBOBJ(err)
+fi
+
+# Look for imsg_init in libutil.
+AC_SEARCH_LIBS(imsg_init, util, found_imsg_init=yes, found_imsg_init=no)
+if test "x$found_imsg_init" = xyes; then
+	AC_DEFINE(HAVE_IMSG)
+else
+	AC_LIBOBJ(imsg)
+	AC_LIBOBJ(imsg-buffer)
+fi
+
+# Look for daemon, compat/daemon.c used if missing. Solaris 10 has it in
+# libresolv, but no declaration anywhere, so check for declaration as well as
+# function.
+AC_CHECK_FUNC(daemon, found_daemon=yes, found_daemon=no)
+AC_CHECK_DECL(
+	daemon,
+	,
+	found_daemon=no,
+	[
+		#include <stdlib.h>
+		#include <unistd.h>
+	]
+)
+if test "x$found_daemon" = xyes; then
+	AC_DEFINE(HAVE_DAEMON)
+else
+	AC_LIBOBJ(daemon)
+fi
+
+# Look for stravis, compat/{vis,unvis}.c used if missing.
+AC_CHECK_FUNC(stravis, found_stravis=yes, found_stravis=no)
+if test "x$found_stravis" = 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_stravis=no])
+	if test "x$found_stravis" = xno; then
+		AC_MSG_RESULT(yes)
+	fi
+fi
+if test "x$found_stravis" = xyes; then
+	AC_CHECK_DECL(
+		VIS_DQ,
+		,
+		found_stravis=no,
+		[
+			#include <stdlib.h>
+			#include <vis.h>
+		]
+)
+fi
+if test "x$found_stravis" = xyes; then
+	AC_DEFINE(HAVE_VIS)
+else
+	AC_LIBOBJ(vis)
+	AC_LIBOBJ(unvis)
+fi
+
+# Look for fdforkpty and forkpty in libutil.
+AC_SEARCH_LIBS(fdforkpty, util, found_fdforkpty=yes, found_fdforkpty=no)
+if test "x$found_fdforkpty" = xyes; then
+	AC_DEFINE(HAVE_FDFORKPTY)
+else
+	AC_LIBOBJ(fdforkpty)
+fi
+AC_SEARCH_LIBS(forkpty, util, found_forkpty=yes, found_forkpty=no)
+if test "x$found_forkpty" = xyes; then
+	AC_DEFINE(HAVE_FORKPTY)
+fi
+AM_CONDITIONAL(NEED_FORKPTY, test "x$found_forkpty" = xno)
+
+# Look for kinfo_getfile in libutil.
+AC_SEARCH_LIBS(kinfo_getfile, [util util-freebsd])
+
+# Look for a suitable queue.h.
+AC_CHECK_DECL(
+	TAILQ_CONCAT,
+	found_queue_h=yes,
+	found_queue_h=no,
+	[#include <sys/queue.h>]
+)
+AC_CHECK_DECL(
+	TAILQ_PREV,
+	,
+	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 program_invocation_short_name.
+AC_MSG_CHECKING(for program_invocation_short_name)
+AC_LINK_IFELSE([AC_LANG_SOURCE(
+	[
+		#include <errno.h>
+		#include <stdio.h>
+		#include <stdlib.h>
+		int main(void) {
+			const char *cp = program_invocation_short_name;
+			printf("%s\n", cp);
+			exit(0);
+		}
+	])],
+	[AC_DEFINE(HAVE_PROGRAM_INVOCATION_SHORT_NAME) AC_MSG_RESULT(yes)],
+	AC_MSG_RESULT(no)
+)
+
+# Look for prctl(PR_SET_NAME).
+AC_CHECK_DECL(
+	PR_SET_NAME,
+	AC_DEFINE(HAVE_PR_SET_NAME),
+	,
+	[#include <sys/prctl.h>]
+)
+
+# Look for setsockopt(SO_PEERCRED).
+AC_CHECK_DECL(
+	SO_PEERCRED,
+	AC_DEFINE(HAVE_SO_PEERCRED),
+	,
+	[#include <sys/socket.h>]
+)
+
+# 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
+
+# Try to figure out what the best value for TERM might be.
+if test "x$DEFAULT_TERM" = x; then
+	DEFAULT_TERM=screen
+	AC_MSG_CHECKING(TERM)
+	AC_RUN_IFELSE([AC_LANG_SOURCE(
+		[
+			#include <stdio.h>
+			#include <stdlib.h>
+			#if defined(HAVE_CURSES_H)
+			#include <curses.h>
+			#elif defined(HAVE_NCURSES_H)
+			#include <ncurses.h>
+			#endif
+			#include <term.h>
+			int main(void) {
+				if (setupterm("screen-256color", -1, NULL) != OK)
+					exit(1);
+				exit(0);
+			}
+		 ])],
+		 [DEFAULT_TERM=screen-256color],
+		 ,
+		 [DEFAULT_TERM=screen]
+	)
+	AC_RUN_IFELSE([AC_LANG_SOURCE(
+		[
+			#include <stdio.h>
+			#include <stdlib.h>
+			#if defined(HAVE_CURSES_H)
+			#include <curses.h>
+			#elif defined(HAVE_NCURSES_H)
+			#include <ncurses.h>
+			#endif
+			#include <term.h>
+			int main(void) {
+				if (setupterm("tmux", -1, NULL) != OK)
+					exit(1);
+				exit(0);
+			}
+		 ])],
+		 [DEFAULT_TERM=tmux],
+		 ,
+		 [DEFAULT_TERM=screen]
+	)
+	AC_RUN_IFELSE([AC_LANG_SOURCE(
+		[
+			#include <stdio.h>
+			#include <stdlib.h>
+			#if defined(HAVE_CURSES_H)
+			#include <curses.h>
+			#elif defined(HAVE_NCURSES_H)
+			#include <ncurses.h>
+			#endif
+			#include <term.h>
+			int main(void) {
+				if (setupterm("tmux-256color", -1, NULL) != OK)
+					exit(1);
+				exit(0);
+			}
+		 ])],
+		 [DEFAULT_TERM=tmux-256color],
+		 ,
+		 [DEFAULT_TERM=screen]
+	)
+	AC_MSG_RESULT($DEFAULT_TERM)
+fi
+AC_SUBST(DEFAULT_TERM)
+
+# Man page defaults to mdoc.
+MANFORMAT=mdoc
+AC_SUBST(MANFORMAT)
+
+# Figure out the platform.
+AC_MSG_CHECKING(platform)
+case "$host_os" in
+	*aix*)
+		AC_MSG_RESULT(aix)
+		PLATFORM=aix
+		;;
+	*darwin*)
+		AC_MSG_RESULT(darwin)
+		PLATFORM=darwin
+		#
+		# macOS uses __dead2 instead of __dead, like FreeBSD. But it defines
+		# __dead away so it needs to be removed before we can replace it.
+		#
+		AC_DEFINE(BROKEN___DEAD)
+		#
+		# macOS CMSG_FIRSTHDR is broken, so redefine it with a working one.
+		# daemon works but has some stupid side effects, so use our internal
+		# version which has a workaround.
+		#
+		AC_DEFINE(BROKEN_CMSG_FIRSTHDR)
+		AC_LIBOBJ(daemon)
+		AC_LIBOBJ(daemon-darwin)
+		#
+		# macOS wcwidth(3) is bad, so complain and suggest using utf8proc
+		# instead.
+		#
+		if test "x$enable_utf8proc" = x; then
+			AC_MSG_NOTICE([])
+			AC_MSG_NOTICE([	   macOS library support for Unicode is very poor,])
+			AC_MSG_NOTICE([	   particularly for complex codepoints like emojis;])
+			AC_MSG_NOTICE([	   to use these correctly, configuring with])
+			AC_MSG_NOTICE([	   --enable-utf8proc is recommended. To build])
+			AC_MSG_NOTICE([	   without anyway, use --disable-utf8proc])
+			AC_MSG_NOTICE([])
+			AC_MSG_ERROR([must give --enable-utf8proc or --disable-utf8proc])
+		fi
+		;;
+	*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
+		case `/usr/bin/nroff --version 2>&1` in
+			*GNU*)
+				# Solaris 11.4 and later use GNU groff.
+				MANFORMAT=mdoc
+				;;
+			*)
+				# Solaris 2.0 to 11.3 use AT&T nroff.
+				MANFORMAT=man
+				;;
+		esac
+		;;
+	*hpux*)
+		AC_MSG_RESULT(hpux)
+		PLATFORM=hpux
+		;;
+	*cygwin*|*msys*)
+		AC_MSG_RESULT(cygwin)
+		PLATFORM=cygwin
+		;;
+	*haiku*)
+		AC_MSG_RESULT(haiku)
+		PLATFORM=haiku
+		;;
+	*)
+		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$PLATFORM" = xhpux)
+AM_CONDITIONAL(IS_HAIKU, test "x$PLATFORM" = xhaiku)
+AM_CONDITIONAL(IS_UNKNOWN, test "x$PLATFORM" = xunknown)
+
+# Save our CFLAGS/CPPFLAGS/LDFLAGS for the Makefile and restore the old user
+# variables.
+AC_SUBST(AM_CPPFLAGS)
+CPPFLAGS="$SAVED_CPPFLAGS"
+AC_SUBST(AM_CFLAGS)
+CFLAGS="$SAVED_CFLAGS"
+AC_SUBST(AM_LDFLAGS)
+LDFLAGS="$SAVED_LDFLAGS"
+
+# autoconf should create a Makefile.
+AC_CONFIG_FILES(Makefile)
+AC_OUTPUT