dnl call this macro with the minimum required version as an argument

dnl this macro sets and AC_SUBSTs XML_CFLAGS and XML_LIBS

dnl it also sets LIBXML_PKG, used for the pkg-config file

AC_DEFUN([AG_GST_LIBXML2_CHECK],

[

  dnl Minimum required version of libxml2

  dnl default to 2.4.9 if not specified

  LIBXML2_REQ=ifelse([$1],,2.4.9,[$1])

  AC_SUBST(LIBXML2_REQ)

  dnl check for libxml2

  PKG_CHECK_MODULES(XML, libxml-2.0 >= $LIBXML2_REQ,

                    HAVE_LIBXML2=yes, [

                      AC_MSG_RESULT(no)

                      HAVE_LIBXML2=no

                    ])

  if test "x$HAVE_LIBXML2" = "xyes"; then

    AC_DEFINE(HAVE_LIBXML2, 1, [Define if libxml2 is available])

  else

    AC_MSG_ERROR([

        Need libxml2 and development headers/files to build GStreamer.

        You can do without libxml2 if you pass --disable-loadsave to

        configure, but that breaks ABI, so don't do that unless you

        are building for an embedded setup and know what you are doing.

    ])

  fi

  dnl this is for the .pc file

  LIBXML_PKG=', libxml-2.0'

  AC_SUBST(LIBXML_PKG)

  AC_SUBST(XML_LIBS)

  AC_SUBST(XML_CFLAGS)

  dnl XML_LIBS might pull in -lz without zlib actually being on the system, so

  dnl try linking with these LIBS and CFLAGS

  ac_save_CFLAGS=$CFLAGS

  ac_save_LIBS=$LIBS

  CFLAGS="$CFLAGS $XML_CFLAGS"

  LIBS="$LIBS $XML_LIBS"

  AC_TRY_LINK([

#include <libxml/tree.h>

#include <stdio.h>

],[

/* function body */

],

    AC_MSG_NOTICE([Test xml2 program linked]),

    AC_MSG_ERROR([Could not link libxml2 test program.  Check if you have the necessary dependencies.])

  )

  CFLAGS="$ac_save_CFLAGS"

  LIBS="$ac_save_LIBS"

])