dnl AC_TRY_CFLAGS (CFLAGS, [ACTION-IF-WORKS], [ACTION-IF-FAILS])
dnl check if $CC supports a given set of cflags
AC_DEFUN([AC_TRY_CFLAGS],
    [AC_MSG_CHECKING([if $CC supports $1 flags])
    SAVE_CFLAGS="$CFLAGS"
    CFLAGS="$1"
    AC_TRY_COMPILE([],[],[ac_cv_try_cflags_ok=yes],[ac_cv_try_cflags_ok=no])
    CFLAGS="$SAVE_CFLAGS"
    AC_MSG_RESULT([$ac_cv_try_cflags_ok])
    if test x"$ac_cv_try_cflags_ok" = x"yes"; then
        ifelse([$2],[],[:],[$2])
    else
        ifelse([$3],[],[:],[$3])
    fi
])

AC_DEFUN([AC_caolan_CHECK_PACKAGE],
[

AC_ARG_WITH($1,
[  --with-$1[=DIR]      root directory of $1 installation],
with_$1=$withval
if test "${with_$1}" != yes; then
        $1_include="$withval/include"
        $1_libdir="$withval/lib"
fi
)

AC_ARG_WITH($1-include,
[  --with-$1-include=DIR        specify exact include dir for $1 headers],
$1_include="$withval")

AC_ARG_WITH($1-libdir,
[  --with-$1-libdir=DIR        specify exact library dir for $1 library
  --without-$1        disables $1 usage completely],
$1_libdir="$withval")

if test "${with_$1}" != no ; then
        OLD_LIBS=$LIBS
        OLD_LDFLAGS=$LDFLAGS
        OLD_CFLAGS=$CFLAGS
        OLD_CPPFLAGS=$CPPFLAGS

        if test "${$1_libdir}" ; then
                LDFLAGS="$LDFLAGS -L${$1_libdir}"
        fi
        if test "${$1_include}" ; then
                CPPFLAGS="$CPPFLAGS -I${$1_include}"
                CFLAGS="$CFLAGS -I${$1_include}"
        fi

        no_good=no
        AC_CHECK_LIB($3,$2,,no_good=yes)
        AC_CHECK_HEADER($4,,no_good=yes)
        if test "$no_good" = yes; then
dnl     broken
                ifelse([$6], , , [$6])

                LIBS=$OLD_LIBS
                LDFLAGS=$OLD_LDFLAGS
                CPPFLAGS=$OLD_CPPFLAGS
                CFLAGS=$OLD_CFLAGS
        else
dnl     fixed
                ifelse([$5], , , [$5])

                AC_DEFINE(HAVE_PKG_$1)
        fi

fi

])