longlong.m4

来自「一个扑克牌游戏集合的源码,包含了很多基本c-c++语言应用」· M4 代码 · 共 24 行

# longlong.m4 serial 5
dnl Copyright (C) 1999-2004 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 From Paul Eggert.

# Define HAVE_LONG_LONG if 'long long' works.

AC_DEFUN([gl_AC_TYPE_LONG_LONG],
[
  AC_CACHE_CHECK([for long long], ac_cv_type_long_long,
  [AC_TRY_LINK([long long ll = 1LL; int i = 63;],
    [long long llmax = (long long) -1;
     return ll << i | ll >> i | llmax / ll | llmax % ll;],
    ac_cv_type_long_long=yes,
    ac_cv_type_long_long=no)])
  if test $ac_cv_type_long_long = yes; then
    AC_DEFINE(HAVE_LONG_LONG, 1,
      [Define if you have the 'long long' type.])
  fi
])