--- gforth/configure.in	2003/08/17 22:52:33	1.128
+++ gforth/configure.in	2003/08/24 09:56:09	1.130
@@ -323,6 +323,12 @@ AC_TRY_COMPILE(,,ac_nocrossjumping=yes;E
 CFLAGS="$CFLAGS_1"
 AC_MSG_RESULT($ac_nocrossjumping)
 
+# Try if GCC understands __attribute__((unused))
+AC_MSG_CHECKING([how to suppress 'unused variable' warnings])
+AC_TRY_COMPILE(,[int __attribute__((unused)) foo;], MAYBE_UNUSED='__attribute__((unused))',)
+AC_DEFINE_UNQUOTED(MAYBE_UNUSED,$MAYBE_UNUSED,[attribute for possibly unused variables])
+AC_MSG_RESULT($MAYBE_UNUSED)
+
 AC_CHECK_PROG(asm_fs,asm.fs,arch/$machine/asm.fs,,$srcdir/arch/$machine)
 AC_SUBST(asm_fs)
 
@@ -450,8 +456,11 @@ AC_CHECK_LIB(callback,__vacall_r)
 AC_CHECK_LIB(vacall,vacall)
 AC_CHECK_LIB(trampoline,alloc_trampoline)
 FFCALLFLAG="false"
-test $ac_cv_lib_avcall___builtin_avcall = yes && FFCALLFLAG="true" && AC_DEFINE(HAS_FFCALL,,[define this if you want to use the ffcall libraries])
+OLDCALLFLAG="true"
+test $ac_cv_lib_avcall___builtin_avcall = yes && FFCALLFLAG="true" && OLDCALLFLAG="false" && AC_DEFINE(HAS_FFCALL,,[define this if you want to use the ffcall libraries])
+test $ac_cv_lib_avcall___builtin_avcall = no && AC_DEFINE(HAS_OLDCALL,,[define this if you want to use the old call libraries])
 AC_SUBST(FFCALLFLAG)
+AC_SUBST(OLDCALLFLAG)
 if test "$host_os" != "nextstep3"
 then
 	AC_FUNC_MEMCMP