dnl Process this file with autoconf to produce a configure script.

AC_INIT([rsync],[ ],[https://rsync.samba.org/bug-tracking.html])

AC_C_BIGENDIAN
AC_HEADER_DIRENT
AC_HEADER_SYS_WAIT
AC_CHECK_HEADERS(poll.h sys/fcntl.h sys/select.h fcntl.h sys/time.h sys/unistd.h \
    unistd.h utime.h compat.h sys/param.h ctype.h sys/wait.h sys/stat.h \
    sys/ioctl.h sys/filio.h string.h stdlib.h sys/socket.h sys/mode.h grp.h \
    sys/un.h sys/attr.h arpa/inet.h arpa/nameser.h locale.h sys/types.h \
    netdb.h malloc.h float.h limits.h iconv.h libcharset.h langinfo.h mcheck.h \
    sys/acl.h acl/libacl.h attr/xattr.h sys/xattr.h sys/extattr.h dl.h \
    popt.h popt/popt.h linux/falloc.h netinet/in_systm.h netgroup.h \
    zlib.h xxhash.h openssl/md4.h openssl/md5.h zstd.h lz4.h sys/file.h \
    sys/resource.h bsd/string.h)
AC_CHECK_HEADERS([netinet/ip.h], [], [], [[#include <netinet/in.h>]])
AC_HEADER_MAJOR_FIXED

AC_CONFIG_MACRO_DIR([m4])
AC_CONFIG_SRCDIR([byteorder.h])
AC_CONFIG_HEADERS([config.h])
AC_PREREQ([2.69])

PACKAGE_VERSION=`sed -n 's/.*RSYNC_VERSION.*"\(.*\)".*/\1/p' <$srcdir/version.h`

AC_MSG_NOTICE([Configuring rsync $PACKAGE_VERSION])

LDFLAGS=${LDFLAGS-""}

AC_CANONICAL_HOST

dnl define the directory for replacement function since AC_LIBOBJ does not
dnl officially support subdirs and fails with automake
AC_CONFIG_LIBOBJ_DIR([lib])

# We must decide this before testing the compiler.

# Please allow this to default to yes, so that your users have more
# chance of getting a useful stack trace if problems occur.

AC_MSG_CHECKING([whether to include debugging symbols])
AC_ARG_ENABLE(debug,
	AS_HELP_STRING([--disable-debug],[disable to omit debugging symbols and features]))

if test x"$enable_debug" = x"no"; then
    AC_MSG_RESULT(no)
    ac_cv_prog_cc_g=no
else
    AC_MSG_RESULT([yes])
    dnl AC_DEFINE(DEBUG, 1, [Define to turn on debugging code that may slow normal operation])
    # leave ac_cv_prog_cc_g alone; AC_PROG_CC will try to include -g if it can
fi

dnl Checks for programs.
AC_PROG_CC
AC_PROG_CPP
AC_PROG_CXX
AC_PROG_AWK
AC_PROG_EGREP
AC_PROG_INSTALL
AC_PROG_MKDIR_P
AC_SUBST(SHELL)
AC_PATH_PROG([PERL], [perl])
AC_PATH_PROG([PYTHON3], [python3])

AC_DEFINE([_GNU_SOURCE], 1,
          [Define _GNU_SOURCE so that we get all necessary prototypes])

if test x"$ac_cv_prog_cc_stdc" = x"no"; then
	AC_MSG_WARN([rsync requires an ANSI C compiler and you do not seem to have one])
fi

no_lib=''
err_msg=''
nl='
'

AC_ARG_ENABLE(profile,
	AS_HELP_STRING([--enable-profile],[enable to turn on CPU profiling]))
if test x"$enable_profile" = x"yes"; then
	CFLAGS="$CFLAGS -pg"
fi

dnl Coverage build (gcov) for `make coverage`. NOTE: --enable-profile above is
dnl gprof (-pg) and is NOT coverage. -O0 keeps branch coverage meaningful;
dnl -fprofile-update=atomic keeps the shared .gcda counters correct while the
dnl suite runs many rsync processes in parallel.
AC_ARG_ENABLE(coverage,
	AS_HELP_STRING([--enable-coverage],[build with gcov instrumentation for `make coverage`]))
if test x"$enable_coverage" = x"yes"; then
	CFLAGS="$CFLAGS --coverage -fprofile-update=atomic -O0"
	CXXFLAGS="$CXXFLAGS --coverage -fprofile-update=atomic -O0"
	LDFLAGS="$LDFLAGS --coverage"
	AC_DEFINE([GCOV_COVERAGE], 1,
		[Flush gcov counters at exit_cleanup: rsync's children exit via _exit(), which bypasses the gcov atexit handler, so without this no .gcda is written for the receiver/generator/daemon-worker processes.])
fi

dnl openat2(RESOLVE_BENEATH) is used on Linux 5.6+ for the secure resolver.
dnl --disable-openat2 forces the portable per-component O_NOFOLLOW fallback to
dnl run as the primary resolver on ordinary Linux, so that tier is exercised
dnl (and coverage-counted) without needing a pre-5.6 kernel. Behaviour-neutral
dnl by default (the knob only REMOVES a tier when explicitly disabled).
AC_ARG_ENABLE(openat2,
	AS_HELP_STRING([--disable-openat2],[do not use Linux openat2(RESOLVE_BENEATH); force the portable resolver (for exercising the fallback tier)]))

AC_MSG_CHECKING([if md2man can create manpages])
if test x"$ac_cv_path_PYTHON3" = x; then
    AC_MSG_RESULT(no - python3 not found)
    md2man_works=no
else
    md2man_out=`"$srcdir/md2man" --test "$srcdir/rsync-ssl.1.md" 2>&1`
    if test $? = 0; then
	AC_MSG_RESULT(yes)
	md2man_works=yes
    else
	AC_MSG_RESULT(no)
	md2man_works=no
	echo "$md2man_out"
    fi
fi

AC_MSG_CHECKING([if we require man-page building])
AC_ARG_ENABLE([md2man],
	AS_HELP_STRING([--disable-md2man],[disable to omit manpage creation]))
if test x"$enable_md2man" != x"no"; then
    if test -f "$srcdir/rsync.1"; then
	AC_MSG_RESULT(optional)
    else
	AC_MSG_RESULT(required)
	if test x"$md2man_works" = x"no"; then
	    err_msg="$err_msg$nl- You need python3 and either the cmarkgfm OR commonmark python3 lib in order"
	    err_msg="$err_msg$nl  to build manpages based on the git source (manpages are included in the"
	    err_msg="$err_msg$nl  official release tar files)."
	    no_lib="$no_lib md2man"
	fi
    fi
    MAKE_MAN=man
else
    AC_MSG_RESULT(no)
fi

# Specifically, this turns on panic_action handling.
AC_ARG_ENABLE(maintainer-mode,
	AS_HELP_STRING([--enable-maintainer-mode],[enable to turn on extra debug features]))
if test x"$enable_maintainer_mode" = x"yes"; then
	CFLAGS="$CFLAGS -DMAINTAINER_MODE"
fi

# This is needed for our included version of popt.  Kind of silly, but
# I don't want our version too far out of sync.
CFLAGS="$CFLAGS -DHAVE_CONFIG_H"

# If GCC, turn on warnings.
if test x"$GCC" = x"yes"; then
	CFLAGS="$CFLAGS -Wall -W"
fi

AC_ARG_WITH(openssl-conf,
	AS_HELP_STRING([--with-openssl-conf=PATH],[set default OPENSSL_CONF path for rsync]))
case "$with_openssl_conf" in
    *[^-/a-zA-Z0-9.,=@+_]*) AC_MSG_ERROR([Invalid path given to --with-openssl-conf]) ;;
    /*) CFLAGS="$CFLAGS -DSET_OPENSSL_CONF=$with_openssl_conf" ;;
    no|'') ;;
    yes) AC_MSG_ERROR([No path given to --with-openssl-conf]) ;;
    *) AC_MSG_ERROR([Non absolute path given to --with-openssl-conf]) ;;
esac

AC_ARG_WITH(rrsync,
        AS_HELP_STRING([--with-rrsync],[also install the rrsync script and its manpage]))
if test x"$with_rrsync" != x"yes"; then
    with_rrsync=no
else
    MAKE_RRSYNC='rrsync'
    MAKE_RRSYNC_1='rrsync.1'
    GEN_RRSYNC='rrsync.1 rrsync.1.html'
fi
AC_SUBST(with_rrsync)

AC_ARG_WITH(included-popt,
        AS_HELP_STRING([--with-included-popt],[use bundled popt library, not from system]))

AC_ARG_WITH(included-zlib,
        AS_HELP_STRING([--with-included-zlib],[use bundled zlib library, not from system]))

AC_ARG_WITH(secluded-args,
        AS_HELP_STRING([--with-secluded-args],[make --secluded-args option the default]))
if test x"$with_secluded_args" = x"yes"; then
	AC_DEFINE_UNQUOTED(RSYNC_USE_SECLUDED_ARGS, 1, [Define to 1 if --secluded-args should be the default])
fi

AC_ARG_WITH(rsync-path,
	AS_HELP_STRING([--with-rsync-path=PATH],[set default --rsync-path to PATH (default: rsync)]),
	[ RSYNC_PATH="$with_rsync_path" ],
	[ RSYNC_PATH="rsync" ])

AC_DEFINE_UNQUOTED(RSYNC_PATH, "$RSYNC_PATH", [location of rsync on remote machine])

AC_ARG_WITH(rsyncd-conf,
	AS_HELP_STRING([--with-rsyncd-conf=PATH],[set configuration file for rsync server to PATH (default: /etc/rsyncd.conf)]),
	[ if test ! -z "$with_rsyncd_conf" ; then
		case $with_rsyncd_conf in
			yes|no)
				RSYNCD_SYSCONF="/etc/rsyncd.conf"
				;;
			/*)
				RSYNCD_SYSCONF="$with_rsyncd_conf"
				;;
			*)
                                AC_MSG_ERROR(You must specify an absolute path to --with-rsyncd-conf=PATH)
				;;
		esac
	else
		RSYNCD_SYSCONF="/etc/rsyncd.conf"
	fi ],
	[ RSYNCD_SYSCONF="/etc/rsyncd.conf" ])

AC_DEFINE_UNQUOTED(RSYNCD_SYSCONF, "$RSYNCD_SYSCONF", [location of configuration file for rsync server])

AC_ARG_WITH(rsh,
	AS_HELP_STRING([--with-rsh=CMD],[set remote shell command to CMD (default: ssh)]))

AC_CHECK_PROG(HAVE_REMSH, remsh, 1, 0)
if test x$HAVE_REMSH = x1; then
	AC_DEFINE(HAVE_REMSH, 1, [Define to 1 if remote shell is remsh, not rsh])
fi

if test x"$with_rsh" != x; then
	RSYNC_RSH="$with_rsh"
else
	RSYNC_RSH="ssh"
fi
AC_DEFINE_UNQUOTED(RSYNC_RSH, "$RSYNC_RSH", [default -e command])

# Some programs on solaris are only found in /usr/xpg4/bin (or work better than others versions).
AC_PATH_PROG(SHELL_PATH, sh, /bin/sh, [/usr/xpg4/bin$PATH_SEPARATOR$PATH])
AC_PATH_PROG(FAKEROOT_PATH, fakeroot, /usr/bin/fakeroot, [/usr/xpg4/bin$PATH_SEPARATOR$PATH])

AC_ARG_WITH(nobody-user,
    AS_HELP_STRING([--with-nobody-user=USER],[set the default unprivileged user (default nobody)]),
    [ NOBODY_USER="$with_nobody_user" ],
    [ NOBODY_USER="nobody" ])

AC_ARG_WITH(nobody-group,
    AS_HELP_STRING([--with-nobody-group=GROUP],[set the default unprivileged group (default nobody or nogroup)]),
    [ NOBODY_GROUP="$with_nobody_group" ])

if test x"$with_nobody_group" = x; then
    AC_MSG_CHECKING([the group for user "nobody"])
    if grep '^nobody:' /etc/group >/dev/null 2>&1; then
	NOBODY_GROUP=nobody
    elif grep '^nogroup:' /etc/group >/dev/null 2>&1; then
	NOBODY_GROUP=nogroup
    else
	NOBODY_GROUP=nobody # test for others?
    fi
    AC_MSG_RESULT($NOBODY_GROUP)
fi

AC_DEFINE_UNQUOTED(NOBODY_USER, "$NOBODY_USER", [unprivileged user--e.g. nobody])
AC_DEFINE_UNQUOTED(NOBODY_GROUP, "$NOBODY_GROUP", [unprivileged group for unprivileged user])

# rolling-checksum SIMD optimizations
ROLL_SIMD=

AC_MSG_CHECKING([whether to enable rolling-checksum SIMD optimizations])
AC_ARG_ENABLE(roll-simd,
    AS_HELP_STRING([--enable-roll-simd],[enable/disable to control rolling-checksum SIMD optimizations (requires c++)]))

# Clag is crashing with -g -O2, so we'll get rid of -g for now.
CXXFLAGS=`echo "$CXXFLAGS" | sed 's/-g //'`
m4_define(SIMD_X86_64_TEST, [[#include <stdio.h>
#if HAVE_STDLIB_H
#include <stdlib.h>
#endif
#include <immintrin.h>
__attribute__ ((target("default"))) int test_ssse3(int x) { return x; }
__attribute__ ((target("default"))) int test_sse2(int x) { return x; }
__attribute__ ((target("default"))) int test_avx2(int x) { return x; }
__attribute__ ((target("ssse3"))) int test_ssse3(int x) { return x; }
__attribute__ ((target("sse2"))) int test_sse2(int x) { return x; }
__attribute__ ((target("avx2"))) int test_avx2(int x) { return x; }
typedef long long __m128i_u __attribute__((__vector_size__(16), __may_alias__, __aligned__(1)));
typedef long long __m256i_u __attribute__((__vector_size__(32), __may_alias__, __aligned__(1)));
__attribute__ ((target("default"))) void more_testing(char* buf, int len) { }
__attribute__ ((target("ssse3"))) void more_testing(char* buf, int len)
{
    int i;
    for (i = 0; i < (len-32); i+=32) {
	__m128i in8_1, in8_2;
	in8_1 = _mm_lddqu_si128((__m128i_u*)&buf[i]);
	in8_2 = _mm_lddqu_si128((__m128i_u*)&buf[i + 16]);
    }
}
]])

if test x"$enable_roll_simd" = x""; then
    case "$host_os" in
	*linux*) ;;
	*) enable_roll_simd=no ;;
    esac
fi

if test x"$enable_roll_simd" != x"no"; then
    # For x86-64 SIMD, g++ >=5 or clang++ >=7 is required
    if test x"$host_cpu" = x"x86_64" || test x"$host_cpu" = x"amd64"; then
	AC_LANG(C++)
	if test x"$host" = x"$build"; then
	    AC_RUN_IFELSE([AC_LANG_PROGRAM([SIMD_X86_64_TEST],[[if (test_ssse3(42) != 42 || test_sse2(42) != 42 || test_avx2(42) != 42) exit(1);]])],
		[CXX_OK=yes],[CXX_OK=no])
	else
	    AC_COMPILE_IFELSE([AC_LANG_PROGRAM([SIMD_X86_64_TEST])],[CXX_OK=yes],[CXX_OK=no])
	fi
	AC_LANG(C)
	if test x"$CXX_OK" = x"yes"; then
	    # AC_MSG_RESULT() is called below.
	    ROLL_SIMD="$host_cpu"
	elif test x"$enable_roll_simd" = x"yes"; then
	    AC_MSG_RESULT(error)
	    AC_MSG_ERROR(The rolling-checksum SIMD compilation test failed.
Omit --enable-roll-simd to continue without it.)
	fi
    elif test x"$enable_roll_simd" = x"yes"; then
        AC_MSG_RESULT(unavailable)
        AC_MSG_ERROR(The rolling-checksum SIMD optimizations are currently x86_64|amd64 only.
Omit --enable-roll-simd to continue without it.)
    fi
fi

if test x"$ROLL_SIMD" != x""; then
    AC_MSG_RESULT([yes ($ROLL_SIMD)])
    AC_DEFINE(USE_ROLL_SIMD, 1, [Define to 1 to enable rolling-checksum SIMD optimizations])
    ROLL_SIMD='$(ROLL_SIMD_'"$ROLL_SIMD)"
    # We only use c++ for its target attribute dispatching, disable unneeded bulky features
    CXXFLAGS="$CXXFLAGS -fno-exceptions -fno-rtti"
    # Apple often has "g++" as a symlink for clang. Try to find out the truth.
    CXX_VERSION=`$CXX --version 2>/dev/null | head -n 2`
    case "$CXX_VERSION" in
    *clang*) CXXFLAGS="$CXXFLAGS -fno-slp-vectorize" ;; # avoid a performance hit
    esac
else
    AC_MSG_RESULT(no)
fi

AC_SUBST(ROLL_SIMD)

AC_MSG_CHECKING([if assembler accepts noexecstack])
OLD_CFLAGS="$CFLAGS"
CFLAGS="$CFLAGS -Wa,--noexecstack"
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[ ]], [[return 0;]])],
[ NOEXECSTACK='-Wa,--noexecstack' ; AC_MSG_RESULT(yes) ],
[ NOEXECSTACK='' ; AC_MSG_RESULT(no) ])
CFLAGS="$OLD_CFLAGS"
AC_SUBST(NOEXECSTACK)

dnl We need both the SYS_openat2 syscall number and <linux/openat2.h> (for
dnl struct open_how / RESOLVE_BENEATH); some setups have one without the other.
AC_CACHE_CHECK([for openat2],rsync_cv_HAVE_OPENAT2,[
    AC_COMPILE_IFELSE([
        AC_LANG_PROGRAM([[
#include <sys/syscall.h>
#include <linux/openat2.h>
]], [[
struct open_how how;
how.resolve = RESOLVE_BENEATH;
return SYS_openat2 + (int)how.resolve;
]])
    ],
    [rsync_cv_HAVE_OPENAT2=yes], [rsync_cv_HAVE_OPENAT2=no])
])
if test x"$enable_openat2" != x"no"; then
    if test x"$rsync_cv_HAVE_OPENAT2" = x"yes"; then
      AC_DEFINE([HAVE_OPENAT2], 1,
        [Define to use Linux openat2(RESOLVE_BENEATH) in secure_relative_open where available.])
    fi
fi

# arrgh. libc in some old debian version screwed up the largefile
# stuff, getting byte range locking wrong
AC_CACHE_CHECK([for broken largefile support],rsync_cv_HAVE_BROKEN_LARGEFILE,[
AC_RUN_IFELSE([AC_LANG_SOURCE([[
#define _FILE_OFFSET_BITS 64
$ac_includes_default
#ifdef HAVE_FCNTL_H
# include <fcntl.h>
#elif defined HAVE_SYS_FCNTL_H
# include <sys/fcntl.h>
#endif
#ifdef HAVE_SYS_WAIT_H
#include <sys/wait.h>
#endif

int main(void)
{
	struct flock lock;
	int status;
	char tpl[32] = "/tmp/locktest.XXXXXX";
	int fd = mkstemp(tpl);
	if (fd < 0) {
		strcpy(tpl, "conftest.dat");
		fd = open(tpl, O_CREAT|O_RDWR, 0600);
	}

	lock.l_type = F_WRLCK;
	lock.l_whence = SEEK_SET;
	lock.l_start = 0;
	lock.l_len = 1;
	lock.l_pid = 0;
	fcntl(fd,F_SETLK,&lock);
	if (fork() == 0) {
		lock.l_start = 1;
		_exit(fcntl(fd,F_SETLK,&lock) == 0);
	}
	wait(&status);
	unlink(tpl);
	return WEXITSTATUS(status);
}
]])],[rsync_cv_HAVE_BROKEN_LARGEFILE=yes],[rsync_cv_HAVE_BROKEN_LARGEFILE=no],[rsync_cv_HAVE_BROKEN_LARGEFILE=cross])])
if test x"$rsync_cv_HAVE_BROKEN_LARGEFILE" != x"yes"; then
   AC_SYS_LARGEFILE
fi

AC_MSG_CHECKING([whether to enable ipv6])
AC_ARG_ENABLE(ipv6,
AS_HELP_STRING([--disable-ipv6],[disable to omit ipv6 support]),
[ case "$enableval" in
  no)
	AC_MSG_RESULT(no)
	;;
  *)	AC_MSG_RESULT(yes)
	AC_DEFINE(INET6, 1, [true if you have IPv6])
	;;
  esac ],

  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
]], [[
struct sockaddr_in6 sa6;
(void)sa6;
(void)AF_INET6;
]])],
  [AC_MSG_RESULT(yes)
  AC_DEFINE(INET6, 1, [true if you have IPv6])],
  [AC_MSG_RESULT(no)]
))

dnl Do you want to disable use of locale functions
AC_ARG_ENABLE([locale],
	AS_HELP_STRING([--disable-locale],[disable to omit locale features]))
AH_TEMPLATE([CONFIG_LOCALE],
[Undefine if you do not want locale features.  By default this is defined.])
if test x"$enable_locale" != x"no"; then
	AC_DEFINE(CONFIG_LOCALE)
fi

AC_MSG_CHECKING([whether to call shutdown on all sockets])
case $host_os in
	*cygwin* ) AC_MSG_RESULT(yes)
                   AC_DEFINE(SHUTDOWN_ALL_SOCKETS, 1,
			    [Define to 1 if sockets need to be shutdown])
		   ;;
	       * ) AC_MSG_RESULT(no);;
esac

# We default to using our zlib unless --with-included-zlib=no is given.
if test x"$with_included_zlib" != x"no"; then
    with_included_zlib=yes
elif test x"$ac_cv_header_zlib_h" != x"yes"; then
    with_included_zlib=yes
fi
if test x"$with_included_zlib" != x"yes"; then
    AC_CHECK_LIB(z, deflateParams, , [with_included_zlib=yes])
fi

AC_MSG_CHECKING([whether to use included zlib])
if test x"$with_included_zlib" = x"yes"; then
    AC_MSG_RESULT($srcdir/zlib)
    BUILD_ZLIB='$(zlib_OBJS)'
    CFLAGS="-I$srcdir/zlib $CFLAGS"
else
    AC_DEFINE(EXTERNAL_ZLIB, 1, [Define to 1 if using external zlib])
    AC_MSG_RESULT(no)
fi

AC_MSG_CHECKING([whether to enable use of openssl crypto library])
AC_ARG_ENABLE([openssl],
	AS_HELP_STRING([--disable-openssl],[disable to omit openssl crypto library]))
AH_TEMPLATE([USE_OPENSSL],
[Undefine if you do not want to use openssl crypto library.  By default this is defined.])
if test x"$enable_openssl" != x"no"; then
    if test x"$ac_cv_header_openssl_md4_h" = x"yes" && test x"$ac_cv_header_openssl_md5_h" = x"yes"; then
      AC_MSG_RESULT(yes)
      AC_SEARCH_LIBS(EVP_MD_CTX_copy, crypto,
          [AC_DEFINE(USE_OPENSSL)
	   enable_openssl=yes],
          [err_msg="$err_msg$nl- Failed to find EVP_MD_CTX_copy function in openssl crypto lib.";
	   no_lib="$no_lib openssl"])
    else
        AC_MSG_RESULT(no)
	err_msg="$err_msg$nl- Failed to find openssl/md4.h and openssl/md5.h for openssl crypto lib support."
	no_lib="$no_lib openssl"
    fi
    if test x"$enable_md5_asm" != x"yes"; then
	enable_md5_asm=no
    fi
else
    AC_MSG_RESULT(no)
fi

MD5_ASM=

AC_MSG_CHECKING([whether to enable MD5 ASM optimizations])
AC_ARG_ENABLE(md5-asm,
    AS_HELP_STRING([--enable-md5-asm],[enable/disable to control MD5 ASM optimizations]))

if test x"$enable_md5_asm" = x""; then
    case "$host_os" in
	*linux*) ;;
	*) enable_md5_asm=no ;;
    esac
fi

if test x"$enable_md5_asm" != x"no"; then
    if test x"$host_cpu" = x"x86_64" || test x"$host_cpu" = x"amd64"; then
	MD5_ASM="$host_cpu"
    elif test x"$enable_md5_asm" = x"yes"; then
        AC_MSG_RESULT(unavailable)
        AC_MSG_ERROR(The ASM optimizations are currently x86_64|amd64 only.
Omit --enable-md5-asm to continue without it.)
    fi
fi

if test x"$MD5_ASM" != x""; then
    AC_MSG_RESULT([yes ($MD5_ASM)])
    AC_DEFINE(USE_MD5_ASM, 1, [Define to 1 to enable MD5 ASM optimizations])
    MD5_ASM='$(MD5_ASM_'"$MD5_ASM)"
else
    AC_MSG_RESULT(no)
fi

AC_SUBST(MD5_ASM)

ROLL_ASM=

AC_MSG_CHECKING([whether to enable rolling-checksum ASM optimizations])
AC_ARG_ENABLE(roll-asm,
    AS_HELP_STRING([--enable-roll-asm],[enable/disable to control rolling-checksum ASM optimizations (requires --enable-roll-simd)]))

if test x"$ROLL_SIMD" = x""; then
    enable_roll_asm=no
fi

if test x"$enable_roll_asm" = x"yes"; then
    ROLL_ASM="$host_cpu"
    AC_MSG_RESULT([yes ($ROLL_ASM)])
    AC_DEFINE(USE_ROLL_ASM, 1, [Define to 1 to enable rolling-checksum ASM optimizations (requires --enable-roll-simd)])
    ROLL_ASM='$(ROLL_ASM_'"$ROLL_ASM)"
else
    AC_MSG_RESULT(no)
fi

AC_SUBST(ROLL_ASM)

AC_MSG_CHECKING([whether to enable xxhash checksum support])
AC_ARG_ENABLE([xxhash],
	AS_HELP_STRING([--disable-xxhash],[disable to omit xxhash checksums]))
AH_TEMPLATE([SUPPORT_XXHASH],
[Undefine if you do not want xxhash checksums.  By default this is defined.])
if test x"$enable_xxhash" != x"no"; then
    if test x"$ac_cv_header_xxhash_h" = x"yes"; then
	AC_MSG_RESULT(yes)
	AC_SEARCH_LIBS(XXH64_createState, xxhash,
	    [AC_DEFINE(SUPPORT_XXHASH)],
	    [err_msg="$err_msg$nl- Failed to find XXH64_createState function in xxhash lib.";
	     no_lib="$no_lib xxhash"])
    else
	AC_MSG_RESULT(no)
	err_msg="$err_msg$nl- Failed to find xxhash.h for xxhash checksum support.";
	no_lib="$no_lib xxhash"
    fi
else
    AC_MSG_RESULT(no)
fi

AC_MSG_CHECKING([whether to enable zstd compression])
AC_ARG_ENABLE([zstd],
        AS_HELP_STRING([--disable-zstd], [disable to omit zstd compression]))
AH_TEMPLATE([SUPPORT_ZSTD],
[Undefine if you do not want zstd compression.  By default this is defined.])
if test x"$enable_zstd" != x"no"; then
    if test x"$ac_cv_header_zstd_h" = x"yes"; then
	AC_MSG_RESULT(yes)
	AC_SEARCH_LIBS(ZSTD_minCLevel, zstd,
	    [AC_DEFINE(SUPPORT_ZSTD)],
	    [err_msg="$err_msg$nl- Failed to find ZSTD_minCLevel function in zstd lib.";
	     no_lib="$no_lib zstd"])
    else
	AC_MSG_RESULT(no)
	err_msg="$err_msg$nl- Failed to find zstd.h for zstd compression support.";
	no_lib="$no_lib zstd"
    fi
else
    AC_MSG_RESULT(no)
fi

AC_MSG_CHECKING([whether to enable LZ4 compression])
AC_ARG_ENABLE([lz4],
        AS_HELP_STRING([--disable-lz4], [disable to omit LZ4 compression]))
AH_TEMPLATE([SUPPORT_LZ4],
[Undefine if you do not want LZ4 compression.  By default this is defined.])
if test x"$enable_lz4" != x"no"; then
    if test x"$ac_cv_header_lz4_h" = x"yes"; then
	AC_MSG_RESULT(yes)
	AC_SEARCH_LIBS(LZ4_compress_default, lz4,
	    [AC_DEFINE(SUPPORT_LZ4)],
	    [err_msg="$err_msg$nl- Failed to find LZ4_compress_default function in lz4 lib.";
	     no_lib="$no_lib lz4"])
    else
	AC_MSG_RESULT(no)
	err_msg="$err_msg$nl- Failed to find lz4.h for lz4 compression support."
	no_lib="$no_lib lz4"
    fi
else
    AC_MSG_RESULT(no)
fi

if test x"$no_lib" != x; then
    echo ""
    echo "Configure found the following issues:"
    echo "$err_msg"
    echo ""
    echo "See the INSTALL file for hints on how to install the missing libraries and/or"
    echo "how to generate (or fetch) manpages:"
    echo "    https://github.com/RsyncProject/rsync/blob/master/INSTALL.md"
    echo ""
    echo "To disable one or more features, the relevant configure options are:"
    for lib in $no_lib; do
	echo "    --disable-$lib"
    done
    echo ""
    AC_MSG_ERROR(Aborting configure run)
fi

AC_CACHE_CHECK([if makedev takes 3 args],rsync_cv_MAKEDEV_TAKES_3_ARGS,[
AC_RUN_IFELSE([AC_LANG_SOURCE([[
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef MAJOR_IN_MKDEV
#include <sys/mkdev.h>
# if !defined makedev && (defined mkdev || defined _WIN32 || defined __WIN32__)
#  define makedev mkdev
# endif
#elif defined MAJOR_IN_SYSMACROS
#include <sys/sysmacros.h>
#endif

int main(void)
{
	dev_t dev = makedev(0, 5, 7);
	if (major(dev) != 5 || minor(dev) != 7)
		return 1;
	return 0;
}
]])],[rsync_cv_MAKEDEV_TAKES_3_ARGS=yes],[rsync_cv_MAKEDEV_TAKES_3_ARGS=no],[rsync_cv_MAKEDEV_TAKES_3_ARGS=no])])
if test x"$rsync_cv_MAKEDEV_TAKES_3_ARGS" = x"yes"; then
   AC_DEFINE(MAKEDEV_TAKES_3_ARGS, 1, [Define to 1 if makedev() takes 3 args])
fi

AC_CHECK_SIZEOF(int)
AC_CHECK_SIZEOF(long)
AC_CHECK_SIZEOF(long long)
AC_CHECK_SIZEOF(short)
AC_CHECK_SIZEOF(int16_t)
AC_CHECK_SIZEOF(uint16_t)
AC_CHECK_SIZEOF(int32_t)
AC_CHECK_SIZEOF(uint32_t)
AC_CHECK_SIZEOF(int64_t)
AC_CHECK_SIZEOF(off_t)
AC_CHECK_SIZEOF(off64_t)
AC_CHECK_SIZEOF(time_t)
AC_CHECK_SIZEOF(char*)

AC_C_INLINE

AC_TYPE_LONG_DOUBLE_WIDER
ac_cv_c_long_double=$ac_cv_type_long_double_wider
if test $ac_cv_c_long_double = yes; then
  AC_DEFINE([HAVE_LONG_DOUBLE],[1],[Define to 1 if the type `long double' works and has more range or precision than `double'.])
fi

AC_TYPE_UID_T
AC_CHECK_TYPES([mode_t,off_t,size_t,pid_t,id_t])
if test "$cross_compiling" = no; then
    AC_TYPE_GETGROUPS
else
    AC_DEFINE([GETGROUPS_T],[gid_t],[Define to the type of elements in the array set by `getgroups'. Usually this is either `int' or `gid_t'.])
fi
AC_CHECK_MEMBERS([struct stat.st_rdev,
		  struct stat.st_mtimensec,
		  struct stat.st_mtimespec.tv_nsec,
		  struct stat.st_mtim.tv_nsec],,,[
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif])

TYPE_SOCKLEN_T

AC_CACHE_CHECK([for errno in errno.h],rsync_cv_errno, [
    AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <errno.h>]], [[int i = errno]])],[rsync_cv_errno=yes],[rsync_cv_have_errno_decl=no])])
if test x"$rsync_cv_errno" = x"yes"; then
   AC_DEFINE(HAVE_ERRNO_DECL, 1, [Define to 1 if errno is declared in errno.h])
fi

# The following test taken from the cvs sources
# If we can't find connect, try looking in -lsocket, -lnsl, and -linet.
# These need checks to be before checks for any other functions that
#    might be in the same libraries.
# The Irix 5 libc.so has connect and gethostbyname, but Irix 5 also has
# libsocket.so which has a bad implementation of gethostbyname (it
# only looks in /etc/hosts), so we only look for -lsocket if we need
# it.
AC_CHECK_FUNCS(connect)
if test x"$ac_cv_func_connect" = x"no"; then
    case "$LIBS" in
    *-lnsl*) ;;
    *) AC_CHECK_LIB(nsl_s, printf) ;;
    esac
    case "$LIBS" in
    *-lnsl*) ;;
    *) AC_CHECK_LIB(nsl, printf) ;;
    esac
    case "$LIBS" in
    *-lsocket*) ;;
    *) AC_CHECK_LIB(socket, connect) ;;
    esac
    case "$LIBS" in
    *-linet*) ;;
    *) AC_CHECK_LIB(inet, connect) ;;
    esac
    dnl We can't just call AC_CHECK_FUNCS(connect) here, because the value
    dnl has been cached.
    if test x"$ac_cv_lib_socket_connect" = x"yes" ||
       test x"$ac_cv_lib_inet_connect" = x"yes"; then
        # ac_cv_func_connect=yes
        # don't!  it would cause AC_CHECK_FUNC to succeed next time configure is run
        AC_DEFINE(HAVE_CONNECT, 1, [Define to 1 if you have the "connect" function])
    fi
fi

AC_SEARCH_LIBS(inet_ntop, resolv)

# For OS X, Solaris, HP-UX, etc.: figure out if -liconv is needed.  We'll
# accept either iconv_open or libiconv_open, since some include files map
# the former to the latter.
AC_SEARCH_LIBS(iconv_open, iconv)
AC_SEARCH_LIBS(libiconv_open, iconv)

AC_MSG_CHECKING([for iconv declaration])
AC_CACHE_VAL(am_cv_proto_iconv, [
    AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
#if HAVE_STDLIB_H
#include <stdlib.h>
#endif
#include <iconv.h>
extern
#ifdef __cplusplus
"C"
#endif
#if defined(__STDC__) || defined(__cplusplus)
size_t iconv (iconv_t cd, char * *inbuf, size_t *inbytesleft, char * *outbuf, size_t *outbytesleft);
#else
size_t iconv();
#endif
]], [[]])],[am_cv_proto_iconv_arg1=""],[am_cv_proto_iconv_arg1="const"])
      am_cv_proto_iconv="extern size_t iconv (iconv_t cd, $am_cv_proto_iconv_arg1 char * *inbuf, size_t *inbytesleft, char * *outbuf, size_t *outbytesleft);"])
    am_cv_proto_iconv=`echo "[$]am_cv_proto_iconv" | tr -s ' ' | sed 's/( /(/'`
AC_MSG_RESULT([$]{ac_t:-
         }[$]am_cv_proto_iconv)
AC_DEFINE_UNQUOTED(ICONV_CONST, $am_cv_proto_iconv_arg1,
		   [Define as const if the declaration of iconv() needs const.])

dnl AC_MSG_NOTICE([Looking in libraries: $LIBS])

AC_REPLACE_FUNCS([inet_ntop inet_pton])

AC_HAVE_TYPE([struct addrinfo], [#include <netdb.h>])
AC_HAVE_TYPE([struct sockaddr_storage], [
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif])

# Irix 6.5 has getaddrinfo but not the corresponding defines, so use
#   builtin getaddrinfo if one of the defines don't exist
AC_CACHE_CHECK([whether defines needed by getaddrinfo exist],
               rsync_cv_HAVE_GETADDR_DEFINES,[
			AC_EGREP_CPP(yes, [
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
#ifdef AI_PASSIVE
yes
#endif],
			rsync_cv_HAVE_GETADDR_DEFINES=yes,
			rsync_cv_HAVE_GETADDR_DEFINES=no)])
AS_IF([test x"$rsync_cv_HAVE_GETADDR_DEFINES" = x"yes" && test x"$ac_cv_type_struct_addrinfo" = x"yes"],[
	# Tru64 UNIX has getaddrinfo() but has it renamed in libc as
	# something else so we must include <netdb.h> to get the
	# redefinition.
	AC_CHECK_FUNCS(getaddrinfo, ,
		[AC_MSG_CHECKING([for getaddrinfo by including <netdb.h>])
		AC_LINK_IFELSE([AC_LANG_PROGRAM([[
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#include <netdb.h>]], [[getaddrinfo(NULL, NULL, NULL, NULL);]])],[AC_MSG_RESULT([yes])
			AC_DEFINE(HAVE_GETADDRINFO, 1,
				[Define to 1 if you have the "getaddrinfo" function and required types.])],[AC_MSG_RESULT([no])
			AC_LIBOBJ([getaddrinfo])])])
    ],[AC_LIBOBJ([getaddrinfo])])

AC_CHECK_MEMBER([struct sockaddr.sa_len],
		[ AC_DEFINE(HAVE_SOCKADDR_LEN, 1, [Do we have sockaddr.sa_len?]) ],
		[],
		[
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
])

AC_CHECK_MEMBER([struct sockaddr_in.sin_len],
		[ AC_DEFINE(HAVE_SOCKADDR_IN_LEN, 1, [Do we have sockaddr_in.sin_len?]) ],
		[],
		[
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#include <netinet/in.h>
])

AC_CHECK_MEMBER([struct sockaddr_un.sun_len],
		[ AC_DEFINE(HAVE_SOCKADDR_UN_LEN, 1, [Do we have sockaddr_un.sun_len?]) ],
		[],
		[
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#include <netinet/in.h>
])

AC_CHECK_MEMBER([struct sockaddr_in6.sin6_scope_id],
		[ AC_DEFINE(HAVE_SOCKADDR_IN6_SCOPE_ID, 1, [Do we have sockaddr_in6.sin6_scope_id?]) ],
		[],
		[
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#include <netinet/in.h>
])

AC_HAVE_TYPE([struct stat64], [#include <stdio.h>
#if HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif
#if HAVE_SYS_STAT_H
# include <sys/stat.h>
#endif
#if STDC_HEADERS
# include <stdlib.h>
# include <stddef.h>
#else
# if HAVE_STDLIB_H
#  include <stdlib.h>
# endif
#endif
])

# if we can't find strcasecmp, look in -lresolv (for Unixware at least)
#
dnl rsync's I/O readiness loops use poll() rather than select() so that a
dnl file descriptor at or above FD_SETSIZE cannot overflow an fd_set (which
dnl is undefined behaviour and could hang the transfer).  poll() is in
dnl POSIX.1-2001; fail early and clearly if this target lacks it.
dnl
dnl io.c and socket.c include <poll.h> unconditionally, so the HEADER has to
dnl be required too: a system that exposes poll() through some other header
dnl would otherwise pass configure and then fail to compile.
AC_CHECK_FUNCS([poll], , [AC_MSG_ERROR([rsync requires poll(); please report the platform to the rsync developers])])
if test x"$ac_cv_header_poll_h" != x"yes"; then
    AC_MSG_ERROR([rsync requires <poll.h>; please report the platform to the rsync developers])
fi

AC_CHECK_FUNCS(strcasecmp)
if test x"$ac_cv_func_strcasecmp" = x"no"; then
    AC_CHECK_LIB(resolv, strcasecmp)
fi

AC_CHECK_FUNCS(aclsort)
if test x"$ac_cv_func_aclsort" = x"no"; then
    AC_CHECK_LIB(sec, aclsort)
fi

dnl At the moment we don't test for a broken memcmp(), because all we
dnl need to do is test for equality, not comparison, and it seems that
dnl every platform has a memcmp that can do at least that.
dnl AC_FUNC_MEMCMP

AC_FUNC_UTIME_NULL
AC_FUNC_ALLOCA
AC_CHECK_FUNCS(waitpid wait4 getcwd chown chmod lchmod mknod mkfifo fdopendir \
    getrlimit setrlimit \
    fchmod fstat ftruncate strchr readlink link utime utimes lutimes strftime \
    chflags getattrlist mktime innetgr linkat mknodat mkfifoat \
    memmove lchown vsnprintf snprintf vasprintf asprintf setsid strpbrk \
    strlcat strlcpy stpcpy strtol mallinfo mallinfo2 getgroups setgroups geteuid getegid \
    setlocale setmode open64 lseek64 mkstemp64 mtrace va_copy __va_copy \
    seteuid strerror putenv iconv_open locale_charset nl_langinfo getxattr \
    extattr_get_link sigaction sigprocmask setattrlist getgrouplist \
    initgroups utimensat futimens posix_fallocate attropen setvbuf nanosleep usleep \
    setenv unsetenv)

dnl dirfd() is a macro or static inline on several systems (the BSDs), so the
dnl default AC_CHECK_FUNCS link probe -- which declares `char dirfd(void);` and
dnl links against a bare symbol -- gives a false negative there.  Probe it with a
dnl real compile+link that includes <dirent.h> and actually calls dirfd().
AC_CACHE_CHECK([for dirfd], rsync_cv_HAVE_DIRFD,
  [AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <dirent.h>]],
    [[DIR *d = opendir("."); return d ? dirfd(d) < -1 : 0;]])],
    [rsync_cv_HAVE_DIRFD=yes], [rsync_cv_HAVE_DIRFD=no])])
if test x"$rsync_cv_HAVE_DIRFD" = x"yes"; then
    AC_DEFINE([HAVE_DIRFD], 1, [Define to 1 if you have a working dirfd() (function or macro).])
fi

dnl cygwin iconv.h defines iconv_open as libiconv_open
if test x"$ac_cv_func_iconv_open" != x"yes"; then
    AC_CHECK_FUNC(libiconv_open, [ac_cv_func_iconv_open=yes; AC_DEFINE(HAVE_ICONV_OPEN, 1)])
fi

dnl Preallocation stuff (also fallocate, posix_fallocate function tests above):

AC_CACHE_CHECK([for useable fallocate],rsync_cv_have_fallocate,[
AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <fcntl.h>
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif]], [[fallocate(0, 0, 0, 0);]])],[rsync_cv_have_fallocate=yes],[rsync_cv_have_fallocate=no])])
if test x"$rsync_cv_have_fallocate" = x"yes"; then
    AC_DEFINE(HAVE_FALLOCATE, 1, [Define to 1 if you have the fallocate function and it compiles and links without error])
fi

AC_MSG_CHECKING([for FALLOC_FL_PUNCH_HOLE])
AC_PREPROC_IFELSE([AC_LANG_SOURCE([[
        #define _GNU_SOURCE 1
        #include <linux/falloc.h>
        #ifndef FALLOC_FL_PUNCH_HOLE
        #error FALLOC_FL_PUNCH_HOLE is missing
        #endif
    ]])], [
        AC_MSG_RESULT([yes])
        AC_DEFINE([HAVE_FALLOC_FL_PUNCH_HOLE], [1], [Define if FALLOC_FL_PUNCH_HOLE is available.])
    ], [
        AC_MSG_RESULT([no])
    ]
)

AC_MSG_CHECKING([for FALLOC_FL_ZERO_RANGE])
AC_PREPROC_IFELSE([AC_LANG_SOURCE([[
        #define _GNU_SOURCE 1
        #include <linux/falloc.h>
        #ifndef FALLOC_FL_ZERO_RANGE
        #error FALLOC_FL_ZERO_RANGE is missing
        #endif
    ]])], [
        AC_MSG_RESULT([yes])
        AC_DEFINE([HAVE_FALLOC_FL_ZERO_RANGE], [1], [Define if FALLOC_FL_ZERO_RANGE is available.])
    ], [
        AC_MSG_RESULT([no])
    ]
)

AC_CACHE_CHECK([for SYS_fallocate],rsync_cv_have_sys_fallocate,[
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <sys/syscall.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif]], [[syscall(SYS_fallocate, 0, 0, (loff_t)0, (loff_t)0);]])],[rsync_cv_have_sys_fallocate=yes],[rsync_cv_have_sys_fallocate=no])])
if test x"$rsync_cv_have_sys_fallocate" = x"yes"; then
    AC_DEFINE(HAVE_SYS_FALLOCATE, 1, [Define to 1 if you have the SYS_fallocate syscall number])
fi

if test x"$ac_cv_func_posix_fallocate" = x"yes"; then
    AC_MSG_CHECKING([whether posix_fallocate is efficient])
    case $host_os in
    *cygwin*)
	AC_MSG_RESULT(yes)
	AC_DEFINE(HAVE_EFFICIENT_POSIX_FALLOCATE, 1,
		  [Define if posix_fallocate is efficient (Cygwin)])
	;;
    *)
	AC_MSG_RESULT(no)
	;;
    esac
fi

dnl End of preallocation stuff

AC_CHECK_FUNCS(getpgrp tcgetpgrp)
if test $ac_cv_func_getpgrp = yes; then
    AC_FUNC_GETPGRP
fi

AC_ARG_ENABLE(iconv-open,
    AS_HELP_STRING([--disable-iconv-open],[disable to avoid all use of iconv_open()]),
    [], [enable_iconv_open=$ac_cv_func_iconv_open])

if test x"$enable_iconv_open" != x"no"; then
    AC_DEFINE(USE_ICONV_OPEN, 1, [Define to 1 if you want rsync to make use of iconv_open()])
fi

AC_ARG_ENABLE(iconv,
    AS_HELP_STRING([--disable-iconv],[disable to omit the --iconv option]),
    [], [enable_iconv=$enable_iconv_open])
AH_TEMPLATE([ICONV_OPTION],
[Define if you want the --iconv option.  Specifying a value will set the
default iconv setting (a NULL means no --iconv processing by default).])
if test x"$enable_iconv" != x"no"; then
	if test x"$enable_iconv" = x"yes"; then
		AC_DEFINE(ICONV_OPTION, NULL)
	else
		AC_DEFINE_UNQUOTED(ICONV_OPTION, "$enable_iconv")
	fi
	AC_DEFINE(UTF8_CHARSET, "UTF-8", [String to pass to iconv() for the UTF-8 charset.])
fi

AC_CACHE_CHECK([whether chown() modifies symlinks],rsync_cv_chown_modifies_symlink,[
  AC_RUN_IFELSE([AC_LANG_SOURCE([[
#if HAVE_UNISTD_H
# include <unistd.h>
#endif
#include <stdlib.h>
#include <errno.h>
int main(void) {
	char const *dangling_symlink = "conftest.dangle";
	unlink(dangling_symlink);
	if (symlink("conftest.no-such", dangling_symlink) < 0) abort();
	if (chown(dangling_symlink, getuid(), getgid()) < 0 && errno == ENOENT) return 1;
	return 0;
    }]])],[rsync_cv_chown_modifies_symlink=yes],[rsync_cv_chown_modifies_symlink=no],[rsync_cv_chown_modifies_symlink=no])])
if test $rsync_cv_chown_modifies_symlink = yes; then
  AC_DEFINE(CHOWN_MODIFIES_SYMLINK, 1, [Define to 1 if chown modifies symlinks.])
fi

AC_CACHE_CHECK([whether link() can hard-link symlinks],rsync_cv_can_hardlink_symlink,[
  AC_RUN_IFELSE([AC_LANG_SOURCE([[
#ifdef HAVE_FCNTL_H
# include <fcntl.h>
#elif defined HAVE_SYS_FCNTL_H
# include <sys/fcntl.h>
#endif
#if HAVE_UNISTD_H
# include <unistd.h>
#endif
#include <stdlib.h>
#include <errno.h>
#define FILENAME "conftest.dangle"
int main(void) {
	unlink(FILENAME);
	if (symlink("conftest.no-such", FILENAME) < 0) abort();
	unlink(FILENAME "2");
#ifdef HAVE_LINKAT
	if (linkat(AT_FDCWD, FILENAME, AT_FDCWD, FILENAME "2", 0) < 0) return 1;
#else
	if (link(FILENAME, FILENAME "2") < 0) return 1;
#endif
	return 0;
    }]])],[rsync_cv_can_hardlink_symlink=yes],[rsync_cv_can_hardlink_symlink=no],[rsync_cv_can_hardlink_symlink=no])])
if test $rsync_cv_can_hardlink_symlink = yes; then
  AC_DEFINE(CAN_HARDLINK_SYMLINK, 1, [Define to 1 if link() can hard-link symlinks.])
fi

AC_CACHE_CHECK([whether link() can hard-link special files],rsync_cv_can_hardlink_special,[
  AC_RUN_IFELSE([AC_LANG_SOURCE([[
#if HAVE_UNISTD_H
# include <unistd.h>
#endif
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#include <stdlib.h>
#include <errno.h>
#define FILENAME "conftest.fifi"
int main(void) {
	unlink(FILENAME);
	if (mkfifo(FILENAME, 0777) < 0) abort();
	unlink(FILENAME "2");
	if (link(FILENAME, FILENAME "2") < 0) return 1;
	return 0;
    }]])],[rsync_cv_can_hardlink_special=yes],[rsync_cv_can_hardlink_special=no],[rsync_cv_can_hardlink_special=no])])
if test $rsync_cv_can_hardlink_special = yes; then
    AC_DEFINE(CAN_HARDLINK_SPECIAL, 1, [Define to 1 if link() can hard-link special files.])
fi

AC_CACHE_CHECK([for working socketpair],rsync_cv_HAVE_SOCKETPAIR,[
AC_RUN_IFELSE([AC_LANG_SOURCE([[
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif

int main(void) {
       int fd[2];
       return (socketpair(AF_UNIX, SOCK_STREAM, 0, fd) != -1) ? 0 : 1;
}]])],[rsync_cv_HAVE_SOCKETPAIR=yes],[rsync_cv_HAVE_SOCKETPAIR=no],[rsync_cv_HAVE_SOCKETPAIR=cross])])
if test x"$rsync_cv_HAVE_SOCKETPAIR" = x"yes"; then
    AC_DEFINE(HAVE_SOCKETPAIR, 1, [Define to 1 if you have the "socketpair" function])
fi

AC_REPLACE_FUNCS([getpass])

if test x"$with_included_popt" != x"yes"; then
    AC_CHECK_LIB(popt, poptGetContext, , [with_included_popt=yes])
fi
if test x"$ac_cv_header_popt_popt_h" = x"yes"; then
    # If the system has /usr/include/popt/popt.h, we enable the
    # included popt because an attempt to "#include <popt/popt.h>"
    # would use our included header file anyway (due to -I.), and
    # might conflict with the system popt.
    with_included_popt=yes
elif test x"$ac_cv_header_popt_h" != x"yes"; then
    with_included_popt=yes
fi

AC_MSG_CHECKING([whether to use included libpopt])
if test x"$with_included_popt" = x"yes"; then
    AC_MSG_RESULT($srcdir/popt)
    BUILD_POPT='$(popt_OBJS)'
    CFLAGS="-I$srcdir/popt $CFLAGS"
    AC_DEFINE(POPT_SYSCONFDIR, "/etc", [sysconfig dir for popt])
    AC_DEFINE(PACKAGE, "rsync", [package name for rsync])
    if test x"$ALLOCA" != x
    then
	# this can be removed when/if we add an included alloca.c;
	#  see autoconf documentation on AC_FUNC_ALLOCA
	AC_MSG_WARN([included libpopt will use malloc, not alloca (which wastes a small amount of memory)])
    fi
else
    AC_MSG_RESULT(no)
fi

AC_CACHE_CHECK([for unsigned char],rsync_cv_SIGNED_CHAR_OK,[
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[signed char *s = (signed char *)""]])],[rsync_cv_SIGNED_CHAR_OK=yes],[rsync_cv_SIGNED_CHAR_OK=no])])
if test x"$rsync_cv_SIGNED_CHAR_OK" = x"yes"; then
    AC_DEFINE(SIGNED_CHAR_OK, 1, [Define to 1 if "signed char" is a valid type])
fi

AC_CACHE_CHECK([for broken readdir],rsync_cv_HAVE_BROKEN_READDIR,[
AC_RUN_IFELSE([AC_LANG_SOURCE([[
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include <dirent.h>
int main(void) { struct dirent *di; DIR *d = opendir("."); di = readdir(d);
if (di && di->d_name[-2] == '.' && di->d_name[-1] == 0 &&
di->d_name[0] == 0) return 0; return 1;} ]])],[rsync_cv_HAVE_BROKEN_READDIR=yes],[rsync_cv_HAVE_BROKEN_READDIR=no],[rsync_cv_HAVE_BROKEN_READDIR=cross])])
if test x"$rsync_cv_HAVE_BROKEN_READDIR" = x"yes"; then
    AC_DEFINE(HAVE_BROKEN_READDIR, 1, [Define to 1 if readdir() is broken])
fi

AC_CACHE_CHECK([for utimbuf],rsync_cv_HAVE_STRUCT_UTIMBUF,[
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include <utime.h>]], [[struct utimbuf tbuf;  tbuf.actime = 0; tbuf.modtime = 1; return utime("foo.c",&tbuf);]])],[rsync_cv_HAVE_STRUCT_UTIMBUF=yes],[rsync_cv_HAVE_STRUCT_UTIMBUF=no])])
if test x"$rsync_cv_HAVE_STRUCT_UTIMBUF" = x"yes"; then
    AC_DEFINE(HAVE_STRUCT_UTIMBUF, 1, [Define to 1 if you have the "struct utimbuf" type])
fi

AC_CACHE_CHECK([if gettimeofday takes tz argument],rsync_cv_HAVE_GETTIMEOFDAY_TZ,[
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <sys/time.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif]], [[struct timeval tv; return gettimeofday(&tv, NULL);]])],[rsync_cv_HAVE_GETTIMEOFDAY_TZ=yes],[rsync_cv_HAVE_GETTIMEOFDAY_TZ=no])])
if test x"$rsync_cv_HAVE_GETTIMEOFDAY_TZ" != x"no"; then
    AC_DEFINE(HAVE_GETTIMEOFDAY_TZ, 1, [Define to 1 if gettimeofday() takes a time-zone arg])
fi

AC_CACHE_CHECK([for C99 vsnprintf],rsync_cv_HAVE_C99_VSNPRINTF,[
AC_RUN_IFELSE([AC_LANG_SOURCE([[
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include <stdarg.h>
#include <stdio.h>
#if HAVE_STDLIB_H
#include <stdlib.h>
#endif
#include <string.h>
void foo(const char *format, ...) {
       va_list ap;
       int len;
       static char buf[] = "12345678901234567890";

       va_start(ap, format);
       len = vsnprintf(0, 0, format, ap);
       va_end(ap);
       if (len != 5) exit(1);

       if (snprintf(buf, 3, "hello") != 5 || strcmp(buf, "he") != 0) exit(1);
}
int main(void) { foo("hello"); return 0; }
]])],[rsync_cv_HAVE_C99_VSNPRINTF=yes],[rsync_cv_HAVE_C99_VSNPRINTF=no],[rsync_cv_HAVE_C99_VSNPRINTF=cross])])
if test x"$rsync_cv_HAVE_C99_VSNPRINTF" = x"yes"; then
    AC_DEFINE(HAVE_C99_VSNPRINTF, 1, [Define to 1 if vsprintf has a C99-compatible return value])
fi


AC_CACHE_CHECK([for secure mkstemp],rsync_cv_HAVE_SECURE_MKSTEMP,[
AC_RUN_IFELSE([AC_LANG_SOURCE([[#include <stdlib.h>
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include <sys/stat.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
int main(void) {
  struct stat st;
  char tpl[20]="/tmp/test.XXXXXX";
  int fd = mkstemp(tpl);
  if (fd == -1) return 1;
  unlink(tpl);
  if (fstat(fd, &st) != 0) return 1;
  if ((st.st_mode & 0777) != 0600) return 1;
  return 0;
}]])],[rsync_cv_HAVE_SECURE_MKSTEMP=yes],[rsync_cv_HAVE_SECURE_MKSTEMP=no],[rsync_cv_HAVE_SECURE_MKSTEMP=cross])])
if test x"$rsync_cv_HAVE_SECURE_MKSTEMP" = x"yes"; then
    case $host_os in
    hpux*)
	dnl HP-UX has a broken mkstemp() implementation they refuse to fix,
	dnl so we noisily skip using it.  See HP change request JAGaf34426
	dnl for details. (sbonds)
	AC_MSG_WARN(Skipping broken HP-UX mkstemp() -- using mktemp() instead)
	;;
    *)
	AC_DEFINE(HAVE_SECURE_MKSTEMP, 1, [Define to 1 if mkstemp() is available and works right])
	;;
    esac
fi


# Whether mknod()/mknodat() can create a FIFO or a unix-domain socket is a
# property of the target filesystem, not a build-time constant -- e.g. mknod
# makes sockets on Linux but not the BSDs/macOS/Solaris, and a single transfer
# can write to filesystems with different capabilities.  So rsync no longer
# probes this at configure time (a run-test that also misfired when cross-
# compiling); do_mknod*() just try mknod[at]() and, on failure, fall back to
# mkfifo[at]()/socket+bind() per call.  We only need the libc symbols, checked
# above via AC_CHECK_FUNCS (mknod mknodat mkfifo mkfifoat) -- all link tests.

#
# The following test was mostly taken from the tcl/tk plus patches
#
AC_CACHE_CHECK([whether -c -o works],rsync_cv_DASHC_WORKS_WITH_DASHO,[
rm -rf conftest*
cat > conftest.$ac_ext <<EOF
int main(void) { return 0; }
EOF
${CC-cc} -c -o conftest..o conftest.$ac_ext
if test -f conftest..o; then
    rsync_cv_DASHC_WORKS_WITH_DASHO=yes
else
    rsync_cv_DASHC_WORKS_WITH_DASHO=no
fi
rm -rf conftest*
])
if test x"$rsync_cv_DASHC_WORKS_WITH_DASHO" = x"yes"; then
    OBJ_SAVE="#"
    OBJ_RESTORE="#"
    CC_SHOBJ_FLAG='-o $@'
else
    OBJ_SAVE='	@b=`basename $@ .o`;rm -f $$b.o.sav;if test -f $$b.o; then mv $$b.o $$b.o.sav;fi;'
    OBJ_RESTORE='	@b=`basename $@ .o`;if test "$$b.o" != "$@"; then mv $$b.o $@; if test -f $$b.o.sav; then mv $$b.o.sav $$b.o; fi; fi'
    CC_SHOBJ_FLAG=""
fi

AC_SUBST(OBJ_SAVE)
AC_SUBST(OBJ_RESTORE)
AC_SUBST(CC_SHOBJ_FLAG)
AC_SUBST(BUILD_POPT)
AC_SUBST(BUILD_ZLIB)
AC_SUBST(MAKE_RRSYNC)
AC_SUBST(MAKE_RRSYNC_1)
AC_SUBST(GEN_RRSYNC)
AC_SUBST(MAKE_MAN)

AC_CHECK_FUNCS(_acl __acl _facl __facl)
#################################################
# check for ACL support

AC_MSG_CHECKING([whether to support ACLs])
AC_ARG_ENABLE(acl-support,
	AS_HELP_STRING([--disable-acl-support],[disable to omit ACL support]))

if test x"$enable_acl_support" = x"no"; then
    AC_MSG_RESULT(no)
else
    case "$host_os" in
    *sysv5*)
	AC_MSG_RESULT(Using UnixWare ACLs)
	AC_DEFINE(HAVE_UNIXWARE_ACLS, 1, [true if you have UnixWare ACLs])
	AC_DEFINE(SUPPORT_ACLS, 1, [Define to 1 to add support for ACLs])
	;;
    solaris*)
	AC_MSG_RESULT(Using solaris ACLs)
	AC_DEFINE(HAVE_SOLARIS_ACLS, 1, [true if you have solaris ACLs])
	AC_DEFINE(SUPPORT_ACLS, 1)
	;;
    *irix*)
	AC_MSG_RESULT(Using IRIX ACLs)
	AC_DEFINE(HAVE_IRIX_ACLS, 1, [true if you have IRIX ACLs])
	AC_DEFINE(SUPPORT_ACLS, 1)
	;;
    *aix*)
	AC_MSG_RESULT(Using AIX ACLs)
	AC_DEFINE(HAVE_AIX_ACLS, 1, [true if you have AIX ACLs])
	AC_DEFINE(SUPPORT_ACLS, 1)
	;;
    *osf*)
	AC_MSG_RESULT(Using Tru64 ACLs)
	AC_DEFINE(HAVE_TRU64_ACLS, 1, [true if you have Tru64 ACLs])
	AC_DEFINE(SUPPORT_ACLS, 1)
	LIBS="$LIBS -lpacl"
	;;
    darwin*)
	AC_MSG_RESULT(Using OS X ACLs)
	AC_DEFINE(HAVE_OSX_ACLS, 1, [true if you have Mac OS X ACLs])
	AC_DEFINE(SUPPORT_ACLS, 1)
	;;
    *hpux*|*nsk*)
	AC_MSG_RESULT(Using HPUX ACLs)
	AC_DEFINE(HAVE_HPUX_ACLS, 1, [true if you have HPUX ACLs])
	AC_DEFINE(SUPPORT_ACLS, 1)
	;;
    *)
	AC_MSG_RESULT(running tests:)
	AC_CHECK_LIB(acl,acl_get_file)
	AC_CACHE_CHECK([for ACL support],samba_cv_HAVE_POSIX_ACLS,[
	    AC_LINK_IFELSE([AC_LANG_PROGRAM([[
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_ACL_H
#include <sys/acl.h>
#endif]], [[ acl_t acl; int entry_id; acl_entry_t *entry_p; return acl_get_entry( acl, entry_id, entry_p);]])],[samba_cv_HAVE_POSIX_ACLS=yes],[samba_cv_HAVE_POSIX_ACLS=no])])
	AC_MSG_CHECKING(ACL test results)
	if test x"$samba_cv_HAVE_POSIX_ACLS" = x"yes"; then
	    AC_MSG_RESULT(Using posix ACLs)
	    AC_DEFINE(HAVE_POSIX_ACLS, 1, [true if you have posix ACLs])
	    AC_DEFINE(SUPPORT_ACLS, 1)
	    AC_CACHE_CHECK([for acl_get_perm_np],samba_cv_HAVE_ACL_GET_PERM_NP,[
		AC_LINK_IFELSE([AC_LANG_PROGRAM([[
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_ACL_H
#include <sys/acl.h>
#endif]], [[ acl_permset_t permset_d; acl_perm_t perm; return acl_get_perm_np( permset_d, perm);]])],[samba_cv_HAVE_ACL_GET_PERM_NP=yes],[samba_cv_HAVE_ACL_GET_PERM_NP=no])])
	    if test x"$samba_cv_HAVE_ACL_GET_PERM_NP" = x"yes"; then
		AC_DEFINE(HAVE_ACL_GET_PERM_NP, 1, [true if you have acl_get_perm_np])
	    fi
	else
	    if test x"$enable_acl_support" = x"yes"; then
		AC_MSG_ERROR(Failed to find ACL support)
	    else
		AC_MSG_RESULT(No ACL support found)
	    fi
	fi
	;;
    esac
fi

#################################################
# check for extended attribute support
AC_MSG_CHECKING(whether to support extended attributes)
AC_ARG_ENABLE(xattr-support,
    AS_HELP_STRING([--disable-xattr-support],[disable to omit extended attributes]),
    [], [case "$ac_cv_func_getxattr$ac_cv_func_extattr_get_link$ac_cv_func_attropen" in
	*yes*) enable_xattr_support=maybe ;;
	*) enable_xattr_support=no ;;
	esac])
AH_TEMPLATE([SUPPORT_XATTRS],
[Define to 1 to add support for extended attributes])
if test x"$enable_xattr_support" = x"no"; then
    AC_MSG_RESULT(no)
else
    case "$host_os" in
    *linux*|*netbsd*|*cygwin*)
	AC_MSG_RESULT(Using Linux xattrs)
	AC_DEFINE(HAVE_LINUX_XATTRS, 1, [True if you have Linux xattrs (or equivalent)])
	AC_DEFINE(SUPPORT_XATTRS, 1)
	AC_DEFINE(NO_SYMLINK_USER_XATTRS, 1, [True if symlinks do not support user xattrs])
	AC_SEARCH_LIBS(getxattr,attr)
	;;
    darwin*)
	AC_MSG_RESULT(Using OS X xattrs)
	AC_DEFINE(HAVE_OSX_XATTRS, 1, [True if you have Mac OS X xattrs])
	AC_DEFINE(SUPPORT_XATTRS, 1)
	AC_DEFINE(NO_DEVICE_XATTRS, 1, [True if device files do not support xattrs])
	AC_DEFINE(NO_SPECIAL_XATTRS, 1, [True if special files do not support xattrs])
	;;
    freebsd*)
	AC_MSG_RESULT(Using FreeBSD extattrs)
	AC_DEFINE(HAVE_FREEBSD_XATTRS, 1, [True if you have FreeBSD xattrs])
	AC_DEFINE(SUPPORT_XATTRS, 1)
	;;
    solaris*)
	AC_MSG_RESULT(Using Solaris xattrs)
	AC_DEFINE(HAVE_SOLARIS_XATTRS, 1, [True if you have Solaris xattrs])
	AC_DEFINE(SUPPORT_XATTRS, 1)
	AC_DEFINE(NO_SYMLINK_XATTRS, 1, [True if symlinks do not support xattrs])
	;;
    *)
	if test x"$enable_xattr_support" = x"yes"; then
	    AC_MSG_ERROR(Failed to find extended attribute support)
	else
	    AC_MSG_RESULT(No extended attribute support found)
	fi
	;;
    esac
fi

#################################################
# On Linux, POSIX ACLs are stored as the "system.posix_acl_{access,default}"
# xattrs, so we can get/set them through a held O_NOFOLLOW fd (fsetxattr) or a
# dirfd+leaf (setxattrat, AT_SYMLINK_NOFOLLOW) instead of the path-based libacl
# acl_*_file() calls -- making the operation safe against a parent-symlink race.
# This needs POSIX ACLs and the f/at xattr syscalls, which on Linux are
# available whenever <sys/xattr.h> (or <attr/xattr.h>) is -- independent of the
# -X feature (--disable-xattr-support), so we gate on the header, not
# enable_xattr_support.
AH_TEMPLATE([SUPPORT_ACL_FD],
[Define to 1 to do POSIX ACL ops via fd/at xattr syscalls (lib/acl.c)])
AH_TEMPLATE([HAVE_XATTRAT_SYSCALLS],
[Define to 1 if the setxattrat/getxattrat/removexattrat syscalls are available])
if test x"$samba_cv_HAVE_POSIX_ACLS" = x"yes" \
   && { test x"$ac_cv_header_sys_xattr_h" = x"yes" || test x"$ac_cv_header_attr_xattr_h" = x"yes"; }; then
    case "$host_os" in
    *linux*)
	AC_DEFINE(SUPPORT_ACL_FD, 1)
	AC_CACHE_CHECK([for SYS_setxattrat],rsync_cv_have_sys_setxattrat,[
	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <sys/syscall.h>
#include <stdint.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
struct xattr_args { uint64_t value; uint32_t size; uint32_t flags; };]],
	[[struct xattr_args a; a.value = 0; a.size = 0; a.flags = 0;
	  syscall(SYS_setxattrat, 0, ".", 0, "n", &a, sizeof a);
	  syscall(SYS_getxattrat, 0, ".", 0, "n", &a, sizeof a);
	  syscall(SYS_removexattrat, 0, ".", 0, "n");]])],[rsync_cv_have_sys_setxattrat=yes],[rsync_cv_have_sys_setxattrat=no])])
	if test x"$rsync_cv_have_sys_setxattrat" = x"yes"; then
	    AC_DEFINE(HAVE_XATTRAT_SYSCALLS, 1)
	fi
	;;
    esac
fi

#################################################
# Detect a patched libacl providing the race-safe
# *_at ACL entry points (acl_get_file_at/acl_set_file_at/acl_delete_def_file_at,
# ACL_1.3, unreleased upstream).  When present we route the race-safe ACL get/
# set/delete through them on Linux -- race-safe on every kernel (6.13+ uses
# *xattrat; older uses libacl's /proc/self/fd compat).  A stock -lacl lacks these
# symbols, so this stays undefined and the build falls back to lib/acl.c;
# detection must therefore run against the patched lib (CPPFLAGS/LDFLAGS).
AH_TEMPLATE([HAVE_LIBACL_AT],
[Define to 1 if libacl provides acl_get_file_at/acl_set_file_at/acl_delete_def_file_at])
if test x"$samba_cv_HAVE_POSIX_ACLS" = x"yes"; then
    case "$host_os" in
    *linux*)
	AC_CHECK_LIB(acl, acl_get_file_at, [rsync_have_libacl_at=yes], [rsync_have_libacl_at=no])
	if test x"$rsync_have_libacl_at" = x"yes"; then
	    AC_CHECK_FUNCS([acl_set_file_at acl_delete_def_file_at], [], [rsync_have_libacl_at=no])
	fi
	if test x"$rsync_have_libacl_at" = x"yes"; then
	    AC_DEFINE(HAVE_LIBACL_AT, 1)
	fi
	;;
    esac
fi

if test x"$enable_acl_support" = x"no" || test x"$enable_xattr_support" = x"no" || test x"$enable_iconv" = x"no"; then
    AC_MSG_CHECKING([whether $CC supports -Wno-unused-parameter])
    OLD_CFLAGS="$CFLAGS"
    CFLAGS="$CFLAGS -Wno-unused-parameter"
    AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <stdio.h>]], [[printf("hello\n");]])],[rsync_warn_flag=yes],[rsync_warn_flag=no])
    AC_MSG_RESULT([$rsync_warn_flag])
    if test x"$rsync_warn_flag" = x"no"; then
	CFLAGS="$OLD_CFLAGS"
    fi
fi

case "$CC" in
' checker'*|checker*)
    AC_DEFINE(FORCE_FD_ZERO_MEMSET, 1, [Used to make "checker" understand that FD_ZERO() clears memory.])
    ;;
esac

AC_CONFIG_FILES([Makefile lib/dummy zlib/dummy popt/dummy shconfig])
AC_OUTPUT

AC_MSG_RESULT()
AC_MSG_RESULT([    rsync $PACKAGE_VERSION configuration successful])
AC_MSG_RESULT()
