+#
+# Configure a Makefile without clobbering it if it exists and is not out of
+# date. This is modified from:
+# http://www.gnu.org/software/ac-archive/htmldoc/ac_cxx_have_ext_slist.html
+#[AC_CONFIG_COMMANDS($1,${SHELL} ${srcdir}/autoconf/install-sh -c ${srcdir}/$1 $1)
+#
+AC_DEFUN([AC_CONFIG_MAKEFILE],
+[AC_CONFIG_COMMANDS($1,${SHELL} ${srcdir}/autoconf/install-sh -c ${srcdir}/$1 $1,${srcdir}/autoconf/mkinstalldirs `dirname $1`)
+])
+
+#
+# Determine if the printf() functions have the %a format character.
+# This is modified from:
+# http://www.gnu.org/software/ac-archive/htmldoc/ac_cxx_have_ext_slist.html
+AC_DEFUN([AC_C_PRINTF_A],
+[
+ AC_LANG_SAVE
+ AC_LANG_C
+ AC_RUN_IFELSE(
+ AC_LANG_PROGRAM([#include <stdio.h>
+ #include <stdlib.h>],
+ [[[
+ volatile double A, B;
+ char Buffer[100];
+ A = 1;
+ A /= 10.0;
+ sprintf(Buffer, "%a", A);
+ B = atof(Buffer);
+ if (A != B)
+ return (1);
+ if (A != 0x1.999999999999ap-4)
+ return (1);
+ return (0);]]]),
+ ac_c_printf_a=yes,ac_c_printf_a=no)
+ AC_LANG_RESTORE
+ if test "$ac_c_printf_a" = "yes"; then
+ AC_DEFINE([HAVE_PRINTF_A],[1],[Define to have the %a format string])
+ fi
+])
+