+AC_CACHE_CHECK([if readline supports add_history], [dx_cv_rl_add_history], [dnl
+dx_cv_rl_add_history=no
+dx_save_libs=$LIBS
+LIBS="$LIBS $LIBREADLINE"
+AC_LINK_IFELSE([AC_LANG_PROGRAM([dnl
+#include <stdio.h>
+#if HAVE_READLINE_HISTORY_H
+# include <readline/history.h>
+#endif
+], [dnl
+(*add_history)("");
+])], [dx_cv_rl_add_history=yes], [dx_cv_rl_add_history=no])
+LIBS=$dx_save_libs
+])
+
+AS_IF([test x"$dx_cv_rl_add_history" = x"yes"],
+ [AC_DEFINE([HAVE_RL_ADD_HISTORY], [1],
+ [Define to 1 if readline supports add_history.])])
+
+m4_include([lib/gnulib.mk])
+DX_GLSYM_PREFIX([cdecl__])
+
+dnl We provide our own makefile rules for gettext. Disable tracing of
+dnl AM_GNU_GETTEXT to prevent autoreconf from running autopoint, and to
+dnl prevent automake from growing gratuitous error conditions.
+m4_traceoff([AM_GNU_GETTEXT])
+AM_GNU_GETTEXT([external])
+DX_LINGUAS
+
+DX_PROG_FLEX([], [], [FLEX=false])
+DX_PROG_BISON([], [], [BISON=false])
+DX_BISON_COMPAT
+BISON_I18N
+
+BISON_COMPAT=
+AS_IF([test x"$dx_cv_bison_api_header_include" = x"yes"],
+ [BISON_COMPAT="'--define=api.header.include={\"\$(*F).h\"}'"])
+AS_IF([test x"$dx_cv_bison_warn_no_deprecated" = x"yes"],
+ [AS_VAR_APPEND([BISON_COMPAT], ["${BISON_COMPAT:+ }-Wno-deprecated"])])
+AC_SUBST([BISON_COMPAT])
+
+AH_TOP([#include <conf_pre.h>])
+AH_BOTTOM([#include <conf_post.h>])
+
+AC_ARG_WITH([gsl],
+ [AS_HELP_STRING([--with-gsl],
+ [specify whether to build test programs requiring the GNU Scientific Library. [default=auto]]
+ )], [with_gsl=$withval], [with_gsl=auto])
+
+AS_CASE([$with_gsl],
+ [no], [have_gsl=no],
+ [yes], [DX_CHECK_GSL([1.0], [have_gsl=yes])],
+ [DX_CHECK_GSL([1.0], [have_gsl=yes], [have_gsl=no])])
+AM_CONDITIONAL([HAVE_GSL], [test x"$have_gsl" = x"yes"])