acinclude.m4

    ], ac_constant="yes", ac_constant="no"
  )
  if test "$ac_constant" = "yes" ; then
    AC_MSG_RESULT(yes)
    $3
  else
    AC_MSG_RESULT(no)
    $4
  fi
])


dnl CARES_CHECK_GETSERVBYPORT_R
dnl -------------------------------------------------
dnl Test if the getservbyport_r function is available,
dnl and find out how many parameters it takes.

AC_DEFUN([CARES_CHECK_GETSERVBYPORT_R], [
  AC_CHECK_HEADERS(sys/types.h netdb.h)
  #
  AC_MSG_CHECKING([for getservbyport_r])
  AC_LINK_IFELSE([
    AC_LANG_FUNC_LINK_TRY([getservbyport_r])
  ],[
    AC_MSG_RESULT([yes])
    cares_cv_getservbyport_r="yes"
  ],[
    AC_MSG_RESULT([no])
    cares_cv_getservbyport_r="no"
  ])
  #
  if test "$cares_cv_getservbyport_r" != "yes"; then
    AC_MSG_CHECKING([deeper for getservbyport_r])
    AC_LINK_IFELSE([
      AC_LANG_PROGRAM([[
      ]],[[
        getservbyport_r();
      ]])
    ],[
      AC_MSG_RESULT([yes])
      cares_cv_getservbyport_r="yes"
    ],[
      AC_MSG_RESULT([but still no])
      cares_cv_getservbyport_r="no"
    ])
  fi
  #
  if test "$cares_cv_getservbyport_r" = "yes"; then
    AC_MSG_CHECKING([how many arguments getservbyport_r takes])
    cares_cv_getservbyport_r_nargs="unknown"
    #
    AC_COMPILE_IFELSE([
      AC_LANG_PROGRAM([[
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
        extern int
        getservbyport_r(int, const char*, struct servent*,
                        char*, size_t, struct servent**);
      ]],[[
        int p1, res;
        size_t p5;
        char *p2, p4[4096];
        struct servent *p3, *p6;
        res = getservbyport_r(p1, p2, p3, p4, p5, &p6);
      ]])
    ],[
      cares_cv_getservbyport_r_nargs="6"
    ])
    #
    if test "$cares_cv_getservbyport_r_nargs" = "unknown"; then
      AC_COMPILE_IFELSE([
        AC_LANG_PROGRAM([[
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
          extern struct servent*
          getservbyport_r(int, const char*, struct servent*,
                          char*, int);
        ]],[[
          int p1, p5;
          char *p2, p4[4096];
          struct servent *p3, res;
          res = getservbyport_r(p1, p2, p3, p4, p5);
        ]])
      ],[
        cares_cv_getservbyport_r_nargs="5"
      ])
    fi
    #
    if test "$cares_cv_getservbyport_r_nargs" = "unknown"; then
      AC_COMPILE_IFELSE([
        AC_LANG_PROGRAM([[
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
          extern int
          getservbyport_r(int, const char*, struct servent*,
                          struct servent_data*);
        ]],[[
          int p1, res;
          char *p2;
          struct servent *p3;
          struct servent_data *p4;
          res = getservbyport_r(p1, p2, p3, p4);
        ]])
      ],[
        cares_cv_getservbyport_r_nargs="4"
      ])
    fi
    #
    AC_MSG_RESULT([$cares_cv_getservbyport_r_nargs])
    #
    if test "$cares_cv_getservbyport_r_nargs" = "unknown"; then
      AC_MSG_WARN([HAVE_GETSERVBYPORT_R will not be defined])
    else
      AC_DEFINE(HAVE_GETSERVBYPORT_R, 1,
        [Specifies whether getservbyport_r is present])
      AC_DEFINE_UNQUOTED(GETSERVBYPORT_R_ARGS, $cares_cv_getservbyport_r_nargs,
        [Specifies the number of arguments to getservbyport_r])
      if test "$cares_cv_getservbyport_r_nargs" = "4" ; then
        AC_DEFINE(GETSERVBYPORT_R_BUFSIZE, sizeof(struct servent_data),
          [Specifies the size of the buffer to pass to getservbyport_r])
      else
        AC_DEFINE(GETSERVBYPORT_R_BUFSIZE, 4096,
          [Specifies the size of the buffer to pass to getservbyport_r])
      fi
    fi
    #
  fi
])