dnl Copyright (C) 2005, 2006 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.

dnl Check for readline and history libraries.

dnl Modified for PSPP by Ben Pfaff, based on readline.m4 serial 3 from
dnl gnulib, which was written by Simon Josefsson, with help from Bruno
dnl Haible and Oskar Liljeblad.

AC_DEFUN([PSPP_READLINE],
[
  dnl Prerequisites of AC_LIB_LINKFLAGS_BODY.
  AC_REQUIRE([AC_LIB_PREPARE_PREFIX])
  AC_REQUIRE([AC_LIB_RPATH])

  dnl Search for libreadline and define LIBREADLINE, LTLIBREADLINE and
  dnl INCREADLINE accordingly.
  AC_LIB_LINKFLAGS_BODY([readline])
  AC_LIB_LINKFLAGS_BODY([history])

  dnl Add $INCREADLINE to CPPFLAGS before performing the following checks,
  dnl because if the user has installed libreadline and not disabled its use
  dnl via --without-libreadline-prefix, he wants to use it. The AC_TRY_LINK
  dnl will then succeed.
  am_save_CPPFLAGS="$CPPFLAGS"
  AC_LIB_APPENDTOVAR([CPPFLAGS], [$INCREADLINE $INCHISTORY])

  AC_CACHE_CHECK(for readline, gl_cv_lib_readline, [
    gl_cv_lib_readline=no
    am_save_LIBS="$LIBS"
    dnl On some systems, -lreadline doesn't link without an additional
    dnl -lncurses or -ltermcap.
    dnl Try -lncurses before -ltermcap, because libtermcap is unsecure
    dnl by design and obsolete since 1994. Try -lcurses last, because
    dnl libcurses is unusable on some old Unices.
    for extra_lib in "" ncurses termcap curses; do
      LIBS="$am_save_LIBS $LIBREADLINE $LIBHISTORY"
      if test -n "$extra_lib"; then
        LIBS="$LIBS -l$extra_lib"
      fi
      AC_TRY_LINK([#include <stdio.h>
#include <readline/readline.h>
#include <readline/history.h>],
        [readline((char*)0); add_history((char*)0);],
        gl_cv_lib_readline=yes)
      if test "$gl_cv_lib_readline" = yes; then
        if test -n "$extra_lib"; then
          LIBREADLINE="$LIBREADLINE $LIBHISTORY -l$extra_lib"
          LTLIBREADLINE="$LTLIBREADLINE $LTLIBHISTORY -l$extra_lib"
        fi
        break
      fi
    done
    LIBS="$am_save_LIBS"
  ])

  if test "$gl_cv_lib_readline" = yes; then
    AC_DEFINE(HAVE_READLINE, 1, [Define if you have the readline library.])
  fi

  if test "$gl_cv_lib_readline" = yes; then
    AC_MSG_CHECKING([how to link with libreadline])
    AC_MSG_RESULT([$LIBREADLINE])
  else
    dnl If $LIBREADLINE didn't lead to a usable library, we don't
    dnl need $INCREADLINE either.
    CPPFLAGS="$am_save_CPPFLAGS"
    LIBREADLINE=
    LTLIBREADLINE=
    LIBHISTORY=
    LTLIBHISTORY=
  fi
  AC_SUBST(LIBREADLINE)
  AC_SUBST(LTLIBREADLINE)
])

dnl aclocal.m4 ends here