/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*        All Rights Reserved   */

/*
 *      UNIX shell
 */

/* To use stack as temporary workspace across
 * possible storage allocation (eg name lookup)
 * a) get ptr from `relstak'
 * b) can now use `pushstak'
 * c) then reset with `setstak'
 * d) `absstak' gives real address if needed
 */
#define         relstak()       (staktop-stakbot)
#define         absstak(x)      (stakbot+Rcheat(x))
#define         setstak(x)      (staktop=absstak(x))
#define         pushstak(c)     (*staktop++=(c))
#define         zerostak()      (*staktop=0)

/* Used to address an item left on the top of
 * the stack (very temporary)
 */
#define         curstak()       (staktop)

/* `usestak' before `pushstak' then `fixstak'
 * These routines are safe against heap
 * being allocated.
 */
#define         usestak()       {locstak();}

/* for local use only since it hands
 * out a real address for the stack top
 */
extern unsigned char            *locstak();

/* Will allocate the item being used and return its
 * address (safe now).
 */
#define         fixstak()       endstak(staktop)

/* For use after `locstak' to hand back
 * new stack top and then allocate item
 */
extern unsigned char            *endstak();

/* Copy a string onto the stack and
 * allocate the space.
 */
extern unsigned char            *cpystak();

/* Copy a string onto the stack, checking for stack overflow
 * as the copy is done.  Same calling sequence as "movstr".
 */
extern unsigned char            *movstrstak();

/* Move bytes onto the stack, checking for stack overflow
 * as the copy is done.  Same calling sequence as the C
 * library routine "memcpy".
 */
extern unsigned char            *memcpystak();

/* Allocate given ammount of stack space */
extern unsigned char            *getstak();

/* Grow the data segment to include a given location */
extern void             growstak();

/* A chain of ptrs of stack blocks that
 * have become covered by heap allocation.
 * `tdystak' will return them to the heap.
 */
extern struct blk       *stakbsy;

/* Base of the entire stack */
extern unsigned char            *stakbas;

/* Top of entire stack */
extern unsigned char            *brkend;

/* Base of current item */
extern unsigned char            *stakbot;

/* Top of current item */
extern unsigned char            *staktop;

/* Used with tdystak */
extern unsigned char            *savstak();