xref: /third_party/backends/configure.ac

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

dnl ******************************************************************
dnl  Set up autoconf and automake
dnl ******************************************************************
AC_INIT([sane-backends],
        m4_esyscmd_s([tools/git-version-gen --prefix '' .tarball-version]),
        [sane-devel@alioth-lists.debian.net])
AC_PREREQ([2.69])               dnl minimum autoconf version required
AC_CONFIG_MACRO_DIR([m4])
AC_CONFIG_HEADERS([include/sane/config.h])

AM_INIT_AUTOMAKE([1.15 subdir-objects -Wall])
AM_SILENT_RULES

dnl ******************************************************************
dnl  Determine SANE version components and release status
dnl ******************************************************************
AS_IF([test x = "x$AWK"],[AC_PROG_AWK])
AS_IF([test x = "x`echo $VERSION | sed 's/[[.0-9]]//g'`"],
            [is_release=yes],
            [is_release=no])
V_MAJOR=`echo $VERSION | $AWK -F. '{print $1}'`
V_MINOR=`echo $VERSION | $AWK -F. '{print $2}'`
V_REV=`echo $VERSION | $AWK -F. '{print $3}' | sed 's/^\([[0-9]]*\).*/\1/'`;

AC_DEFINE_UNQUOTED(SANE_DLL_V_MAJOR, $V_MAJOR, [SANE DLL major number])
AC_DEFINE_UNQUOTED(SANE_DLL_V_MINOR, $V_MINOR, [SANE DLL minor number])
AC_DEFINE_UNQUOTED(SANE_DLL_V_BUILD, $V_REV, [SANE DLL revision number])
AC_SUBST(V_MAJOR)
AC_SUBST(V_MINOR)
AC_SUBST(V_REV)

dnl ******************************************************************
dnl  Set up the compiler and linker
dnl ******************************************************************
AC_PROG_CC
AC_PROG_CXX
AM_PROG_CC_C_O
AM_PATH_PYTHON(2.7)
sane_save_CC=$CC
AC_PROG_CC_C99                  dnl enables extensions to ISO C99 :-(
AS_IF([test xno != "x$ac_cv_prog_cc_c99"],
      [AC_MSG_CHECKING([for $sane_save_CC option for ISO C99 w/o extensions])
       AS_CASE([$ac_cv_prog_cc_c99],
               [-std=gnu99],      [sane_prog_cc_c99="-std=c99"],
               [-qlanglvl=extc99],[sane_prog_cc_c99="-qlanglvl=stdc99"])
       AS_IF([test "x$ac_cv_prog_cc_c99" = "x$sane_prog_cc_c99"],
             [AC_MSG_RESULT([$ac_cv_prog_cc_99])],
             [AC_MSG_RESULT([$sane_prog_cc_c99])
              CC="$sane_save_CC $sane_prog_cc_c99"])
      ])
AC_PROG_GCC_TRADITIONAL
AC_USE_SYSTEM_EXTENSIONS        dnl call before running the C compiler

AM_PROG_AR
LT_INIT([disable-static win32-dll])
LT_PREREQ([2.4.6])

dnl *****************************************************************
dnl  Set up I18N/L10N support
dnl *****************************************************************
AM_GNU_GETTEXT([external])
AM_GNU_GETTEXT_VERSION([0.19.8])

dnl ***********************************************************************
dnl Checks for programs.
dnl ***********************************************************************
AC_PATH_PROG(SANE_CONFIG_PATH, sane-config, no)

dnl Call explicitly before using PKG_*
PKG_PROG_PKG_CONFIG

AM_CONDITIONAL(CROSS_COMPILING, test x$cross_compiling = xyes)

dnl ***********************************************************************
dnl set compiler/linker flags
dnl ***********************************************************************
SANE_SET_AM_CFLAGS([$is_release])
AX_CXX_COMPILE_STDCXX_11([noext], [optional])
SANE_SET_AM_LDFLAGS

dnl ***********************************************************************
dnl Checks for unix variants
dnl ***********************************************************************
AC_SEARCH_LIBS([strerror],[cposix])

AC_NEED_BYTEORDER_H([include/byteorder.h])
AX_CREATE_STDINT_H([include/_stdint.h])

dnl ***********************************************************************
dnl Checks for libraries
dnl ***********************************************************************
AC_ARG_ENABLE(dynamic,
	AS_HELP_STRING([--disable-dynamic],
		       [Disable dynamic loading of backends]),
	[enable_dynamic=$enableval], [enable_dynamic=auto])
SANE_CHECK_DLL_LIB
dnl Checks for Backend libraries.
AC_CHECK_LIB(m, sqrt, MATH_LIB="-lm")
AC_SUBST(MATH_LIB)
case ${host_os} in
  os2*)
  AC_CHECK_LIB(syslog, syslog, SYSLOG_LIBS="-lsyslog")
  ;;
  beos*)
  AC_CHECK_LIB(be, syslog, SYSLOG_LIBS="-lbe")
  ;;
esac
AC_SUBST(SYSLOG_LIBS)

SANE_CHECK_JPEG
SANE_CHECK_TIFF
SANE_CHECK_PNG
SANE_CHECK_IEEE1284
SANE_CHECK_PTHREAD
SANE_CHECK_LOCKING
SANE_CHECK_GPHOTO2


AC_ARG_WITH(v4l,
	    AS_HELP_STRING([--with-v4l],
			   [include the v4l backend @<:@default=yes@:>@]),
	    [# If --with-v4l=no or --without-v4l, disable backend
             # as "$with_v4l" will be set to "no"])

if test "$with_v4l" != "no" ; then
  PKG_CHECK_MODULES(LIBV4L, [libv4l1 >= 0.8.3], have_libv4l1=yes, have_libv4l1=no)
fi

AC_ARG_WITH(avahi,
  AS_HELP_STRING([--with-avahi],
    [enable Avahi support @<:@default=check@:>@]),
  [],
  [with_avahi=check])
AC_DEFINE(WITH_AVAHI,
  [0], [Define to 1 if Avahi support is available])
AS_IF([test xno != "x$with_avahi"],
  [PKG_CHECK_MODULES(AVAHI, [avahi-client >= 0.6.24],
    [AC_DEFINE([WITH_AVAHI], [1])
     with_avahi=yes
    ],
    [AS_IF([test xcheck != "x$with_avahi"],
       [AC_MSG_ERROR([Avahi support requested but not found])])
     with_avahi=no
    ])
  ])
AM_CONDITIONAL([have_libavahi], [test x != "x$AVAHI_LIBS"])

dnl check sane to make sure we don't have two installations
AC_CHECK_LIB(sane, sane_init, LIBSANE_EXISTS="yes")


dnl **************************************************************
dnl Check for libsnmp availability
dnl **************************************************************

AC_ARG_WITH(snmp,
  AS_HELP_STRING([--with-snmp],
    [enable SNMP support @<:@default=check@:>@]),
  [],
  [with_snmp=check])
AC_DEFINE(HAVE_LIBSNMP,
  [0], [Define to 1 if libsnmp is available])
AS_IF([test xno != "x$with_snmp"],
  [PKG_CHECK_MODULES(SNMP, [netsnmp >= 5.6],
    [AC_DEFINE([HAVE_LIBSNMP], [1])
     with_snmp=yes
    ],
    [AS_IF([test xcheck != "x$with_snmp"],
       [AC_MSG_ERROR([libsnmp requested but not found])])
     with_snmp=no
    ])
  ])
AM_CONDITIONAL([have_snmp], [test x != "x$SNMP_LIBS"])

dnl ***********************************************************************
dnl Checks for header files.
dnl ***********************************************************************
AC_HEADER_STDC
AC_CHECK_HEADERS(fcntl.h unistd.h libc.h sys/dsreq.h sys/select.h \
    sys/time.h sys/shm.h sys/ipc.h sys/scanio.h os2.h \
    sys/socket.h sys/io.h sys/hw.h sys/types.h linux/ppdev.h \
    dev/ppbus/ppi.h machine/cpufunc.h sys/sem.h poll.h \
    windows.h be/kernel/OS.h limits.h sys/ioctl.h asm/types.h\
    netinet/in.h tiffio.h ifaddrs.h pwd.h getopt.h)
AC_CHECK_HEADERS([asm/io.h],,,[#include <sys/types.h>])

SANE_CHECK_MISSING_HEADERS

AC_CHECK_HEADERS(winsock2.h, SOCKET_LIB="-lws2_32")

AC_CHECK_HEADER(resmgr.h,[
	AC_CHECK_LIB(
		resmgr,
		rsm_open_device,[
			AC_DEFINE(HAVE_RESMGR,1,[define if you have the resmgr library])
			RESMGR_LIBS="-lresmgr"
		]
	)
])
AC_SUBST(RESMGR_LIBS)

dnl ***********************************************************************
dnl Checks for types and structures
dnl ***********************************************************************

AC_TYPE_SIZE_T
AC_TYPE_PID_T
AC_TYPE_SSIZE_T
SANE_CHECK_U_TYPES

# from Python, check for "long long" type
AC_MSG_CHECKING(for long long support)
have_long_long=no
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[long long x; x = (long long)0;]])],[AC_DEFINE(HAVE_LONG_LONG, 1, Define if the long long type is available.) have_long_long=yes],[])
AC_MSG_RESULT($have_long_long)

AC_MSG_CHECKING([for socklen_t in <sys/socket.h>])
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
#include <sys/socket.h>
]], [[socklen_t len]])],AC_MSG_RESULT(yes),
[AC_MSG_RESULT(no); AC_DEFINE(socklen_t,int,
[Define socklen_t as \'int\' if necessary.])])

AC_MSG_CHECKING([for union semun in <sys/sem.h>])
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/sem.h>
]], [[union semun test_semun]])],[AC_MSG_RESULT(yes);
AC_DEFINE(HAVE_UNION_SEMUN,1,[Define if union semun is available.])],
[AC_MSG_RESULT(no)])

AC_MSG_CHECKING([for struct flock in fcntl.h])
AC_EGREP_HEADER([struct flock], fcntl.h, [AC_MSG_RESULT(yes) ;
                AC_DEFINE(HAVE_STRUCT_FLOCK, 1,
                [Define if struct flock is available.])], AC_MSG_RESULT(no))

AC_MSG_CHECKING([for Linux ioctl defines])
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
#include <sys/ioctl.h>
#include <asm/types.h>
]],[[
__u32 houba = _IOR('v',14, unsigned long);
]])],[AC_MSG_RESULT(yes);
have_linux_ioctl_defines="yes";],AC_MSG_RESULT(no))

dnl ***********************************************************************
dnl Checks for compiler characteristics
dnl ***********************************************************************
AC_C_BIGENDIAN
AC_C_CONST
AC_C_INLINE

dnl ***********************************************************************
dnl Checks for library functions
dnl ***********************************************************************

dnl Functions for which we provide an implementation if missing
AC_CONFIG_LIBOBJ_DIR([lib])
AC_FUNC_ALLOCA
AC_REPLACE_FUNCS([getenv inet_ntop inet_pton sigprocmask \
    sleep snprintf strcasestr strdup strndup strsep syslog usleep \
    vsyslog])
AS_IF([test x != x$ALLOCA],
      [LTALLOCA=`echo "$ALLOCA" | sed 's/\.o$//; s/\.obj$//'`.lo])
AC_SUBST(LTALLOCA)

dnl Define SOCKET_LIB, NSL_LIB, BIND_LIB, and RESOLV_LIB  when required
dnl for functions we use.
AC_CHECK_FUNC(gethostbyaddr,, [AC_CHECK_LIB(bind, gethostbyaddr, BIND_LIB="-lbind")])
AC_CHECK_FUNC(gethostbyaddr,, [AC_CHECK_LIB(nsl, gethostbyaddr, NSL_LIB="-lnsl")])
AC_CHECK_FUNC(socket,, [AC_CHECK_LIB(socket, socket, SOCKET_LIB="-lsocket")])
AC_CHECK_FUNC(inet_aton,, [AC_CHECK_LIB(resolv, inet_aton, RESOLV_LIB="-lresolv")])

dnl Group related network libraries together so they can always be linked
dnl in.
SOCKET_LIBS="$SOCKET_LIB $NSL_LIB $BIND_LIB $RESOLV_LIB"
AC_SUBST(SOCKET_LIBS)

dnl define HAVE_* values for network functions.  This may require
dnl SOCKET_LIBS so set LIBS temporarily.
save_LIBS="$LIBS"
LIBS="$LIBS $SOCKET_LIBS"
AC_CHECK_FUNCS(inet_addr inet_aton inet_ntoa)
LIBS="$save_LIBS"

if test "$ac_cv_header_be_kernel_OS_h" = "yes" ; then
    dnl those are known to be broken in BeOS (BONE)
    ac_cv_func_getaddrinfo=no
    ac_cv_func_getnameinfo=no
fi

AC_FUNC_MMAP
AC_CHECK_FUNCS(atexit ioperm i386_set_ioperm \
    mkdir strftime strstr strtod  \
    cfmakeraw tcsendbreak strcasecmp strncasecmp _portaccess \
    getaddrinfo getnameinfo poll setitimer iopl getuid getpass)

dnl sys/io.h might provide ioperm but not inb,outb (like for
dnl non i386/x32/x86_64 with musl libc)
if test "${ac_cv_header_sys_io_h}" = "yes"; then
  AC_MSG_CHECKING([for inb,outb (provided by sys/io.h)])
  AC_LINK_IFELSE(
    [AC_LANG_PROGRAM([[#include <sys/io.h>]],
      [[inb(0);outb(0,0);]])],
    [AC_MSG_RESULT([yes])
      sane_cv_have_sys_io_h_with_inb_outb="yes"],
    [AC_MSG_RESULT([no])
      sane_cv_have_sys_io_h_with_inb_outb="no"
      AC_MSG_WARN([sys/io.h does not provide inb,outb (non i386/x32/x86_64 arch?)])])
  if test "$sane_cv_have_sys_io_h_with_inb_outb" = "yes"; then
    AC_DEFINE(SANE_HAVE_SYS_IO_H_WITH_INB_OUTB, 1, [Define to 1 if you have the <sys/io.h> providing inb,outb.])
  fi
else
  sane_cv_have_sys_io_h_with_inb_outb="no"
fi

SANE_PROTOTYPES

if test "$ac_cv_header_os2_h" = "yes" ; then
  AC_DEFINE(strncasecmp, strnicmp, [Define for OS/2 only])
  AC_DEFINE(strcasecmp, stricmp, [Define for OS/2 only])
fi

if test "$ac_cv_header_getopt_h" = "yes" ; then
  AC_CHECK_FUNCS(getopt_long)
fi

# Slightly abuse the AC_LIBOBJ macro to mark files as replacement code
AS_IF([test x$ac_cv_header_getopt_h != xyes \
       && test x$ac_cv_func_getopt_long != xyes],
      [AC_LIBOBJ(getopt)
       AC_LIBOBJ(getopt1)])

dnl ***********************************************************************
dnl checks for system services
dnl ***********************************************************************
if test -c /dev/urandom ; then
    AC_DEFINE(HAVE_DEV_URANDOM, 1, [Is /dev/urandom available?])
fi

AC_ARG_WITH(systemd,
	AS_HELP_STRING([--with-systemd], [enable systemd support @<:@default=yes@:>@]))
if test "x$with_systemd" != xno ; then
  PKG_CHECK_MODULES(SYSTEMD, [libsystemd], have_systemd=yes, have_systemd=no)
  if test "x$have_systemd" = xno; then
    PKG_CHECK_MODULES(SYSTEMD, [libsystemd-daemon], have_systemd=yes, have_systemd=no)
  fi
  if test "x$have_systemd" = xyes; then
    AC_DEFINE(HAVE_SYSTEMD, 1, [Is /usr/include/systemd/sd-daemon.h available?])
  else
    if test "x$with_systemd" = xyes; then
      AC_MSG_ERROR([Systemd support was requested but systemd was not found])
    fi
  fi
fi

dnl ******************************************************************
dnl Check for USB support
dnl ******************************************************************

AC_ARG_WITH(usb,
  AS_HELP_STRING([--with-usb], [enable USB support @<:@default=check@:>@]),
  [],
  [with_usb=check])
AS_IF([test xno != "x$with_usb"],
  [have_usb=no
   AS_CASE(x$host_os,           dnl odd-ball operating systems first
    [xbeos*],
      [AC_CHECK_HEADER(be/drivers/USB_scanner.h, [have_usb=yes])],
    [xos2*],
      [AC_CHECK_HEADER(usbcalls.h,
        [AC_CHECK_LIB(usbcall, UsbQueryNumberDevices,
          [USB_LIBS="-lusbcall"
           have_usb=yes
           AC_DEFINE(HAVE_USBCALLS, [1],
             [Define to 1 if you have usbcall.dll.])
          ])
        ],
        [],
        [#include <usb.h>
         #include <os2.h>
        ])
      ],
    [dnl default to libusb-1.x, fall back to libusb-0.x if missing
     PKG_CHECK_MODULES([USB], [libusb-1.0],
      [AC_DEFINE([HAVE_LIBUSB], [1],
        [Define to 1 if you have libusb-1.0])
       have_usb=yes
      ],
      [PKG_CHECK_MODULES([USB], [libusb >= 0.1.8],
        [AC_DEFINE([HAVE_LIBUSB_LEGACY], [1],
          [Define to 1 if you have libusb-0.1])
         have_usb=yes
        ],
        [dnl 10+ years old libusb or Windows version
         AC_CHECK_HEADER(usb.h,
          AC_CHECK_LIB(usb, usb_interrupt_read,
            [USB_LIBS="-lusb"
             have_usb=yes
            ]))
         AC_CHECK_HEADERS(lusb0_usb.h,
           AC_CHECK_LIB(usb, usb_interrupt_read,
             [USB_LIBS="-lusb"
              have_usb=yes
             ]))
        ])
      ])
    ])
  ])
AS_IF([test xyes = "x$with_usb" && test xyes != "x$have_usb"],
  [AC_MSG_ERROR([USB support requested but required libraries not found.])
  ])
AM_CONDITIONAL([have_usblib], [test x != "x$USB_LIBS"])

dnl ******************************************************************
dnl Check for libcurl availability
dnl ******************************************************************
AC_ARG_WITH(libcurl,
  AS_HELP_STRING([--with-libcurl],
    [enable functionality that needs libcurl @<:@default=check@:>@]),
  [],
  [with_libcurl=check])
AC_DEFINE(HAVE_LIBCURL,
  [0], [Define to 1 if libcurl is available])
AS_IF([test xno != "x$with_libcurl"],
  [PKG_CHECK_MODULES(libcurl, [libcurl],
     [AC_DEFINE([HAVE_LIBCURL], [1])
      with_libcurl=yes
     ],
     [AS_IF([test xcheck != "x$with_libcurl"],
        [AC_MSG_ERROR([libcurl requested but not found])])
      with_libcurl=no
     ])
  ])
AM_CONDITIONAL([have_libcurl], [test x != "x$libcurl_LIBS"])

dnl ******************************************************************
dnl Check for poppler-glib availability
dnl ******************************************************************
AC_ARG_WITH(poppler-glib,
  AS_HELP_STRING([--with-poppler-glib],
    [enable functionality that needs poppler-glib @<:@default=check@:>@]),
  [],
  [with_poppler_glib=check])
AC_DEFINE(HAVE_POPPLER_GLIB,
  [0], [Define to 1 if libpoppler-glib is available])
AS_IF([test xno != "x$with_poppler_glib"],
  [PKG_CHECK_MODULES(POPPLER_GLIB, [poppler-glib],
     [AC_DEFINE([HAVE_POPPLER_GLIB], [1])
      with_poppler_glib=yes
     ],
     [AS_IF([test xcheck != "x$with_poppler_glib"],
        [AC_MSG_ERROR([poppler-glib requested but not found])])
      with_poppler_glib=no
     ])
  ])
AM_CONDITIONAL([have_poppler_glib], [test x != "x$POPPLER_GLIB_LIBS"])

dnl ******************************************************************
dnl Check for USB record/replay support
dnl ******************************************************************
AC_ARG_WITH(usb_record_replay,
            AS_HELP_STRING([--with-usb-record-replay],
                           [enable USB record and replay to XML files @<:@default=yes@:>@]))

if test "x$with_usb_record_replay" != "xno"; then
  PKG_CHECK_MODULES([XML], [libxml-2.0], have_libxml=yes, have_libxml=no)
  if test "x$have_libxml" = xyes; then
    AC_DEFINE(HAVE_LIBXML2, 1, [Define to 1 if libxml2 is available])
    AC_DEFINE(WITH_USB_RECORD_REPLAY, 1, [define if USB record replay is enabled])
  else
    if test "x$with_usb_record_replay" = xyes; then
      AC_MSG_ERROR([USB record and replay support was requested but libxml-2.0 was not found])
    fi
  fi
fi
AM_CONDITIONAL([have_libxml2], [test x != "x$XML_LIBS"])

dnl ************
dnl SCSI Support
dnl ************

dnl FIXME: These are a lot of header files to scan.  We should
dnl scan for just one that is unique per platform and then do
dnl conditional scans for more specific only as needed.

# Unset VERSION during the SCSI header check
sed "s!^#define VERSION .*!/* & */!" confdefs.h > confdefs.h.tmp
mv confdefs.h.tmp confdefs.h

AC_CHECK_HEADERS(IOKit/scsi/SCSITaskLib.h IOKit/cdb/IOSCSILib.h \
  IOKit/scsi/SCSICommandOperationCodes.h \
  IOKit/scsi-commands/SCSICommandOperationCodes.h scsi.h sys/scsi.h \
  sys/scsicmd.h sys/scsiio.h bsd/dev/scsireg.h scsi/sg.h \
  camlib.h gscdds.h sys/scsi/scsi.h sys/scsi/sgdefs.h \
  sys/scsi/targets/scgio.h apollo/scsi.h sys/sdi_comm.h \
  sys/passthrudef.h)

# Restore VERSION
sed "s!/\* \(#define VERSION .*\) \*/!\1!" confdefs.h > confdefs.h.tmp
mv confdefs.h.tmp confdefs.h

AC_CHECK_HEADERS([io/cam/cam.h],,,[#include <io/common/iotypes.h>])
AC_CHECK_HEADERS([ntddscsi.h ddk/ntddscsi.h],,,[#include <windows.h>])

dnl FreeBSD < 3
if test "$ac_cv_header_sys_scsiio_h" = "yes" \
  && test "$ac_cv_header_scsi_h" = "yes"; then
  AC_MSG_CHECKING([if 'scsireq_t' needs to be defined as 'struct scsireq'])
  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
#include <sys/scsiio.h>
#include <scsi.h>
]], [[scsireq_t req]])],,
   [AC_MSG_RESULT(yes);
    AC_DEFINE(scsireq_t, struct scsireq_t,
	      [Define scsireq_t as \'struct scsireq\' if necessary.])])
fi
AC_CHECK_LIB(scsi, scsireq_enter, SCSI_LIBS="-lscsi") # FreeBSD needs this

dnl FreeBSD >= 3
AC_CHECK_LIB(cam, cam_open_device, SCSI_LIBS="-lcam")  # FreeBSD 3+ needs this

AC_CHECK_FUNCS(scsireq_enter)

if test "$ac_cv_header_scsi_sg_h" = "yes"; then
  AC_MSG_CHECKING([for sg_header.target_status in <scsi/sg.h>])
  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
#include <sys/types.h>
#include <scsi/sg.h>
]],[[
struct sg_header hdr;
hdr.target_status = 1;
return 0;
]])],[AC_MSG_RESULT(yes);
   AC_DEFINE(HAVE_SG_TARGET_STATUS,1,
	     [Define if sg_header.target_status is available.])],
	     AC_MSG_RESULT(no))
fi

if test "$ac_cv_header_IOKit_scsi_SCSITaskLib_h" = "yes"; then
  AC_MSG_CHECKING([for SCSITaskSGElement in IOKit/scsi/SCSITaskLib.h])
  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
#undef VERSION
#include <IOKit/scsi/SCSITaskLib.h>
]],[[
SCSITaskSGElement range;
return 0;
]])],[AC_MSG_RESULT(yes);
  AC_DEFINE(HAVE_SCSITASKSGELEMENT, 1,
	    [Define if SCSITaskSGElement is available.])],
  AC_MSG_RESULT(no))
fi

# Multiple platforms can set SCSI_LIBS so do substitution at end.
AC_SUBST(SCSI_LIBS)

AC_ARG_ENABLE(scsibuffersize,
  AS_HELP_STRING([--enable-scsibuffersize=N],
                 [specify the default size in bytes of the buffer for SCSI
                  commands @<:@default=131072@:>@]),
  [set_scsibuffersize="$enableval"], [set_scsibuffersize=131072])
AC_DEFINE_UNQUOTED(SCSIBUFFERSIZE, $set_scsibuffersize,
                   [SCSI command buffer size])
dnl FIXME: Move this to configuration printout area but probably
dnl but probably needs to be wrapped by what ever uses it so its
dnl only printed when used.
echo "scsi buffersize: $set_scsibuffersize"

AC_ARG_ENABLE(scsi-directio,
  AS_HELP_STRING([--enable-scsi-directio],
                 [enable SCSI direct IO (Linux only, dangerous, see
                  README.linux)]),
  [
    if eval "test x$enable_scsi_directio = xyes"; then
      AM_CFLAGS="$AM_CFLAGS -DENABLE_SCSI_DIRECTIO"
    fi
  ])

dnl ****
dnl IPv6
dnl ****

dnl check for IPv6 (can be overridden by --enable-ipv6)
if test "$ac_cv_func_getnameinfo" = "yes" \
  && test "$ac_cv_func_getaddrinfo" = "yes" ; then
  SANE_CHECK_IPV6
else
  ipv6="no"
fi

dnl ***********************************************************************
dnl initialize libtool
dnl ***********************************************************************
AC_ARG_ENABLE(preload,
	AS_HELP_STRING([--disable-preload],
		       [Disable preloading of backends]),
	[enable_preload=$enableval], [enable_preload=auto])

dnl Windows (cygwin/mingw), BeOS, and OS/2 need this.
case $host_os in
  cygwin* | mingw* | beos* | os2*)
  AM_LDFLAGS="$AM_LDFLAGS -no-undefined"
esac

dnl Check for lock dir

AC_ARG_WITH(lockdir, AS_HELP_STRING([--with-lockdir=DIR],
                                    [set SANE lockdir @<:@localstatedir/lock@:>@]),
                                    [locksanedir=$withval],[locksanedir=${localstatedir}/lock])
AC_SUBST(locksanedir)

configdir="${sysconfdir}/sane.d"
AC_SUBST(configdir)

dnl ***********************************************************************
dnl enable/disable backends and features based on previous tests and user's
dnl choice
dnl ***********************************************************************

AM_CPPFLAGS="${AM_CPPFLAGS} -DPATH_SANE_CONFIG_DIR=\$(configdir) \
	  -DPATH_SANE_DATA_DIR=\$(datadir) \
	  -DPATH_SANE_LOCK_DIR=\$(locksanedir) \
	  -DV_MAJOR=${V_MAJOR} -DV_MINOR=${V_MINOR}"

if test "${ac_cv_header_sys_socket_h}" = "no"; then
  echo "*** disabling saned (sys/socket.h not found)"
  SANED=
else
  SANED=saned
fi
AM_CONDITIONAL(COMPILE_SANED, test x$SANED = xsaned)

dnl These are the backends that are build in any case:

AC_ARG_ENABLE(local-backends,
  AS_HELP_STRING([--disable-local-backends],
                 [turn off compilation of all backends but net]))

ALL_BACKENDS="abaton agfafocus apple artec artec_eplus48u as6e \
        avision bh canon canon630u canon_dr canon_lide70 canon_pp cardscan \
        coolscan coolscan2 coolscan3 dc25 dc210 dc240 \
        dell1600n_net dmc epjitsu epson epson2 epsonds escl fujitsu \
        genesys gphoto2 gt68xx hp hp3500 hp3900 hp4200 hp5400 \
        hp5590 hpsj5s hpljm1005 hs2p ibm kodak kodakaio kvs1025 kvs20xx \
        kvs40xx leo lexmark ma1509 magicolor \
        matsushita microtek microtek2 mustek mustek_pp \
        mustek_usb mustek_usb2 nec net niash pie pieusb pint \
        pixma plustek plustek_pp qcam ricoh ricoh2 rts8891 s9036 \
        sceptre sharp sm3600 sm3840 snapscan sp15c st400 \
        stv680 tamarack teco1 teco2 teco3 test u12 umax \
        umax_pp umax1220u v4l xerox_mfp p5"

# If user specifies backends manually then cause configure
# to fail if its detected it can't be compiled.  If we
# are in automatic mode then remove backend from list instead.
user_selected_backends="yes"

AC_ARG_VAR(BACKENDS, [list of backends to compile])
if eval "test x$enable_local_backends = xno"; then
   BACKENDS="net"
else
  if test "${BACKENDS}" != "" ; then
    AC_MSG_NOTICE([Manually selected backends: ${BACKENDS}])
  else
    BACKENDS="$ALL_BACKENDS"
    user_selected_backends="no"
  fi
fi

if test "${sane_cv_use_libjpeg}" = "yes"; then
  SANEI_SANEI_JPEG_LO="../sanei/sanei_jpeg.lo"
  saved_LIBS="${LIBS}"
  LIBS="${JPEG_LIBS}"
  AC_CHECK_FUNCS(jpeg_crop_scanline jpeg_skip_scanlines)
  LIBS="${saved_LIBS}"
fi
AM_CONDITIONAL(HAVE_JPEG, test x$sane_cv_use_libjpeg = xyes)
AC_SUBST(SANEI_SANEI_JPEG_LO)

SANE_CHECK_BACKENDS

AC_ARG_ENABLE(pnm-backend,
  AS_HELP_STRING([--enable-pnm-backend],
                 [enable the pnm backend for testing frontends (possible security risk, see PROBLEMS file)]),
                 [FILTERED_BACKENDS="${FILTERED_BACKENDS} pnm"],
                 [echo "*** pnm backend not manually selected - disabling"])

BACKENDS="$FILTERED_BACKENDS"
BACKEND_LIBS_ENABLED=""
BACKEND_CONFS_ENABLED=""
BACKEND_MANS_ENABLED=""
for backend in ${BACKENDS} ; do
  BACKEND_LIBS_ENABLED="${BACKEND_LIBS_ENABLED} libsane-${backend}.la"
  BACKEND_CONFS_ENABLED="${BACKEND_CONFS_ENABLED} ${backend}.conf"
  BACKEND_MANS_ENABLED="${BACKEND_MANS_ENABLED} sane-${backend}.5"
  if test x$backend = xgenesys; then
    with_genesys_tests=yes
  fi
  if test x$backend = xumax_pp; then
    install_umax_pp_tools=yes
  fi
done
AC_SUBST(BACKEND_LIBS_ENABLED)
AM_CONDITIONAL(WITH_GENESYS_TESTS, test xyes = x$with_genesys_tests)
AM_CONDITIONAL(INSTALL_UMAX_PP_TOOLS, test xyes = x$install_umax_pp_tools)

AC_ARG_VAR(PRELOADABLE_BACKENDS, [list of backends to preload into single DLL])
if test "${enable_preload}" = "auto"; then
  if test "${enable_shared}" = "no" || test "${enable_dynamic}" != "yes"; then
    enable_preload=yes
  fi
fi
if test "${enable_preload}" = "yes"; then
  echo "preloading backends into DLL"

  # If user specifies backends manually then cause configure
  # to fail if its detected it can't be compiled.  If we
  # are in automatic mode then remove backend from list instead.
  user_selected_backends="yes"

  if eval "test x$enable_local_backends = xno"; then
    PRELOADABLE_BACKENDS="net"
  else
    if test "${PRELOADABLE_BACKENDS}" != "" ; then
      AC_MSG_NOTICE([Manually selected preloadable backends: ${PRELOADABLE_BACKENDS}])
    else
      PRELOADABLE_BACKENDS="$BACKENDS"
      user_selected_backends="no"
    fi
  fi

  saved_BACKENDS="$BACKENDS"
  BACKENDS="${PRELOADABLE_BACKENDS}"

  SANE_CHECK_BACKENDS

  PRELOADABLE_BACKENDS="$FILTERED_BACKENDS"
  BACKENDS="$saved_BACKENDS"
else
  PRELOADABLE_BACKENDS=""
fi
PRELOADABLE_BACKENDS_ENABLED=""
# Do not initialize BACKEND_CONFS_ENABLED so that its a combination
# of all backends.
for backend in ${PRELOADABLE_BACKENDS} ; do
  BACKEND_CONFS_ENABLED="${BACKEND_CONFS_ENABLED} ${backend}.conf"
  BACKEND_MANS_ENABLED="${BACKEND_MANS_ENABLED} sane-${backend}.5"
  # Special hacks.  Normally, we create a convenience library that
  # matches the backend's name but in some cases that will conflict
  # with an external library name that also matches backend name.
  # Work around that here by renaming internal library.
  if test "${backend}" = "gphoto2"; then
    backend=gphoto2_i
  fi
  PRELOADABLE_BACKENDS_ENABLED="${PRELOADABLE_BACKENDS_ENABLED} lib${backend}.la"
done
AM_CONDITIONAL([preloadable_backends_enabled],
        [test x != "x$PRELOADABLE_BACKENDS_ENABLED"])

AC_SUBST(PRELOADABLE_BACKENDS)
AC_SUBST(PRELOADABLE_BACKENDS_ENABLED)
AC_SUBST(BACKEND_CONFS_ENABLED)
AC_SUBST(BACKEND_MANS_ENABLED)

dnl in BeOS, backends are not installed in lib/sane, but add-ons/sane/
dnl we account for both installing in /boot/beos and ~/config
case $host_os in
  beos*)
  libdir='${exec_prefix}/add-ons'
  ;;
esac

AC_ARG_ENABLE(parport-directio,
  AS_HELP_STRING([--enable-parport-directio],
                 [enable direct hardware access to the parallel port, so
                  frontends will require special permission level]),
  [
    if eval "test x$enable_parport_directio = xyes"; then
      AM_CFLAGS="$AM_CFLAGS -DENABLE_PARPORT_DIRECTIO"
    fi
  ])

dnl ***********************************************************************
dnl Write output files
dnl ***********************************************************************

AC_SUBST(AM_CPPFLAGS)
AC_SUBST(AM_CFLAGS)
AC_SUBST(AM_CXXFLAGS)
AC_SUBST(AM_LDFLAGS)

AC_CONFIG_FILES([Makefile lib/Makefile sanei/Makefile frontend/Makefile \
  japi/Makefile backend/Makefile include/Makefile doc/Makefile \
  po/Makefile.in testsuite/Makefile \
  testsuite/backend/Makefile \
  testsuite/backend/genesys/Makefile \
  testsuite/sanei/Makefile testsuite/tools/Makefile \
  tools/Makefile doc/doxygen-sanei.conf doc/doxygen-genesys.conf])
AC_CONFIG_FILES([tools/sane-config], [chmod a+x tools/sane-config])
AC_CONFIG_FILES([tools/sane-backends.pc])
AC_OUTPUT

dnl ***********************************************************************
dnl print configuration information
dnl ***********************************************************************

echo "-> Variables used for compilation/linking:"
echo AM_CPPFLAGS=\"${AM_CPPFLAGS}\"
echo AM_CFLAGS=\"${AM_CFLAGS}\"
echo AM_CXXFLAGS=\"${AM_CXXFLAGS}\"
echo AM_LDFLAGS=\"${AM_LDFLAGS}\"
echo LIBS=\"${LIBS}\"
echo "-> Installation directories:"
echo "Configuration: `eval eval echo ${sysconfdir}`"
echo "Libraries:     `eval eval echo ${libdir}`"
echo "Binaries:      `eval eval echo ${bindir}` and `eval eval echo ${sbindir}`"
echo "Manpages:      `eval eval echo ${mandir}`"
echo "Documentation: `eval eval echo ${docdir}`"
if eval "test x$INSTALL_LOCKPATH = xinstall-lockpath" ; then
  echo "Lockfiles:     `eval eval echo ${locksanedir}`"
else
  echo "Lockfiles:     Feature is disabled!"
fi
echo "-> Network parameters:"
if test "${SANED}" = "saned" ; then
  echo "Build saned:   yes"
else
  echo "Build saned:   no"
fi
echo "IPv6 support:  `eval eval echo ${ipv6}`"
echo "Avahi support: `eval eval echo ${with_avahi}`"
echo "cURL support:  `eval eval echo ${with_libcurl}`"
echo "POPPLER_GLIB support:  `eval eval echo ${with_poppler_glib}`"
echo "SNMP support:  `eval eval echo ${with_snmp}`"
echo "-> The following backends will be built:"
for backend in ${BACKENDS} ; do
  echo $ECHO_N "${backend} "
done
echo
echo
echo "-> The following preload backends will be built:"
for backend in ${PRELOADABLE_BACKENDS} ; do
  echo $ECHO_N "${backend} "
done
echo

if test "$SANE_CONFIG_PATH" != "no" ; then
  SANE_INSTALLED_VERSION=`$SANE_CONFIG_PATH --version`
  SANE_INSTALLED_PREFIX=`$SANE_CONFIG_PATH --prefix`
  if test "$SANE_INSTALLED_PREFIX" != "$prefix" ; then
    echo "*** WARNING: SANE is already installed (version $SANE_INSTALLED_VERSION). The old"
    echo "*** installation is at $SANE_INSTALLED_PREFIX while SANE will now be installed"
    echo "*** at $prefix. It is recommended to uninstall the old SANE version"
    echo "*** before installing the new one to avoid problems."
  fi
else
  if test "$LIBSANE_EXISTS" = "yes" ; then
    echo "*** Warning: An old version of SANE was detected but the sane-config program"
    echo "*** couldn't be found. If you encounter any problems with SANE remove the old"
    echo "*** SANE files and reinstall this version."
  fi
fi
if eval "test x${sysconfdir} = x/usr/etc" ; then
  echo "*** WARNING: Configuration files are stored in /usr/etc. If this is not"
  echo "*** intended, use --sysconfdir to set another path (e.g. "/etc")."
fi
if test "$SELECTED_BACKENDS" != "" ; then
  echo "*** Warning: Local backends have been disabled.  This means that scanners"
  echo "*** connected to your local computer won't be supported.  Only a network"
  echo "*** connection to a remote host is possible."
fi
if test "$with_usb" != "no" && test "$have_usb" != "yes" ; then
  echo "*** Warning: sane-backends will be built without USB support.  There may"
  echo "*** be valid reasons to do so, e.g. if you don't use USB scanners or on"
  echo "*** platforms without USB support but generally this means that you"
  echo "*** can't use USB devices with SANE. The most probable cause is that"
  if test "${ac_cv_header_usb_h}" != "yes"; then
    echo "*** the libusb header file usb.h is not installed. If you use Linux"
    echo "*** you may need a package called 'libusb-dev', 'libusb-devel' or similar."
  else
    echo "*** libusb is not installed at all or is too old. See README."
  fi
fi

echo "****************************************************************"
echo "* Please be sure to read file PROBLEMS in this directory       *"
echo "* BEFORE running any of the SANE applications.  Some devices   *"
echo "* may be damaged by improper operation, so please do heed this *"
echo "* advice.                                                      *"
echo "****************************************************************"