acinclude.m4

  AC_CACHE_CHECK([for compiler support of old gcc variadic macro style],
    [curl_cv_variadic_macros_gcc], [
    AC_COMPILE_IFELSE([
      AC_LANG_PROGRAM([
#define gcc_vmacro3(first, args...) fun3(first, args)
#define gcc_vmacro2(first, args...) fun2(first, args)
        int fun3(int arg1, int arg2, int arg3);
        int fun2(int arg1, int arg2);
        int fun3(int arg1, int arg2, int arg3)
        { return arg1 + arg2 + arg3; }
        int fun2(int arg1, int arg2)
        { return arg1 + arg2; }
      ],[
        int res3 = gcc_vmacro3(1, 2, 3);
        int res2 = gcc_vmacro2(1, 2);
      ])
    ],[
      curl_cv_variadic_macros_gcc="yes"
    ],[
      curl_cv_variadic_macros_gcc="no"
    ])
  ])
  case "$curl_cv_variadic_macros_gcc" in
    yes)
      AC_DEFINE_UNQUOTED(HAVE_VARIADIC_MACROS_GCC, 1,
        [Define to 1 if compiler supports old gcc variadic macro style.])
      ;;
  esac
])