Source to include/stdarg.h

0001  /* 
0002  Copyright (C) 1988 Free Software Foundation
0003  
0004  This file is part of GNU CC.
0005  
0006  GNU CC is distributed in the hope that it will be useful,
0007  but WITHOUT ANY WARRANTY.  No author or distributor
0008  accepts responsibility to anyone for the consequences of using it
0009  or for whether it serves any particular purpose or works at all,
0010  unless he says so in writing.  Refer to the GNU CC General Public
0011  License for full details.
0012  
0013  Everyone is granted permission to copy, modify and redistribute
0014  GNU CC, but only under the conditions described in the
0015  GNU CC General Public License.   A copy of this license is
0016  supposed to have been given to you along with GNU CC so you
0017  can know your rights and responsibilities.  It should be in a
0018  file named COPYING.  Among other things, the copyright notice
0019  and this notice must be preserved on all copies.  
0020  */
0021  
0022  #ifndef __stdarg_h
0023  #define __stdarg_h
0024  
0025  typedef char *va_list;
0026  
0027  /* Amount of space required in an argument list for an arg of type TYPE.
0028     TYPE may alternatively be an expression whose type is used.  */
0029  
0030  #define __va_rounded_size(TYPE)  \
0031    (((sizeof (TYPE) + sizeof (int) - 1) / sizeof (int)) * sizeof (int))
0032  
0033  #define va_start(AP, LASTARG) \
0034   (AP = ((char *) &(LASTARG) + __va_rounded_size(LASTARG)))
0035  
0036  extern void va_end (va_list);
0037  #define va_end(AP) /* Nothing */
0038  
0039  #define va_arg(AP, TYPE) (AP += __va_rounded_size (TYPE), \
0040    *((TYPE *) (AP - __va_rounded_size (TYPE))))
0041  
0042  #endif /* __stdarg_h */