/* Copyright (C) 1993, 1995, 1997, 1998 Aladdin Enterprises.  All rights reserved.
  
  This file is part of AFPL Ghostscript.
  
  AFPL Ghostscript is distributed with NO WARRANTY OF ANY KIND.  No author or
  distributor accepts any responsibility for the consequences of using it, or
  for whether it serves any particular purpose or works at all, unless he or
  she says so in writing.  Refer to the Aladdin Free Public License (the
  "License") for full details.
  
  Every copy of AFPL Ghostscript must include a copy of the License, normally
  in a plain ASCII text file named PUBLIC.  The License grants you the right
  to copy, modify and redistribute AFPL Ghostscript, but only under certain
  conditions described in the License.  Among other things, the License
  requires that the copyright notice and this notice be preserved on all
  copies.
*/

/*$Id$ */
/* Definitions for operator operand checking */
/* Requires ialloc.h (for imemory), iref.h, errors.h */

#ifndef opcheck_INCLUDED
#  define opcheck_INCLUDED

/*
 * Check the type of an object.  Operators almost always use check_type,
 * which is defined in oper.h; check_type_only is for checking
 * subsidiary objects obtained from places other than the stack.
 */
#define check_type_only(rf,typ)\
  BEGIN if ( !r_has_type(&rf,typ) ) return_error(e_typecheck); END
#define check_stype_only(rf,styp)\
  BEGIN if ( !r_has_stype(&rf,imemory,styp) ) return_error(e_typecheck); END
/* Check for array */
#define check_array_else(rf,errstat)\
  BEGIN if ( !r_has_type(&rf, t_array) ) errstat; END
#define check_array_only(rf)\
  check_array_else(rf, return_error(e_typecheck))
/* Check for procedure.  check_proc_failed includes the stack underflow */
/* check, but it doesn't do any harm in the off-stack case. */
int check_proc_failed(P1(const ref *));

#define check_proc(rf)\
  BEGIN if ( !r_is_proc(&rf) ) return_error(check_proc_failed(&rf)); END
#define check_proc_only(rf) check_proc(rf)

/* Check for read, write, or execute access. */
#define check_access(rf,acc1)\
  BEGIN if ( !r_has_attr(&rf,acc1) ) return_error(e_invalidaccess); END
#define check_read(rf) check_access(rf,a_read)
#define check_write(rf) check_access(rf,a_write)
#define check_execute(rf) check_access(rf,a_execute)
#define check_type_access_only(rf,typ,acc1)\
  BEGIN\
    if ( !r_has_type_attrs(&rf,typ,acc1) )\
      return_error((!r_has_type(&rf,typ) ? e_typecheck : e_invalidaccess));\
  END
#define check_read_type_only(rf,typ)\
  check_type_access_only(rf,typ,a_read)
#define check_write_type_only(rf,typ)\
  check_type_access_only(rf,typ,a_write)

/* Check for an integer value within an unsigned bound. */
#define check_int_leu(orf, u)\
  BEGIN\
    check_type(orf, t_integer);\
    if ( (ulong)(orf).value.intval > (u) ) return_error(e_rangecheck);\
  END
#define check_int_leu_only(rf, u)\
  BEGIN\
    check_type_only(rf, t_integer);\
    if ( (ulong)(rf).value.intval > (u) ) return_error(e_rangecheck);\
  END
#define check_int_ltu(orf, u)\
  BEGIN\
    check_type(orf, t_integer);\
    if ( (ulong)(orf).value.intval >= (u) ) return_error(e_rangecheck);\
  END

#endif /* opcheck_INCLUDED */