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/*
* 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 1992 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* UNIX shell
*/
#include "defs.h"
/* ======== storage allocation ======== */
unsigned char *
getstak(asize) /* allocate requested stack */
int asize;
{
unsigned char *oldstak;
int size;
size = round(asize, BYTESPERWORD);
oldstak = stakbot;
staktop = stakbot += size;
if (staktop >= brkend)
growstak(staktop);
return(oldstak);
}
/*
* set up stack for local use
* should be followed by `endstak'
*/
unsigned char *
locstak()
{
if (brkend - stakbot < BRKINCR)
{
if (setbrk(brkincr) == -1)
error(nostack);
if (brkincr < BRKMAX)
brkincr += 256;
}
return(stakbot);
}
void
growstak(newtop)
unsigned char *newtop;
{
unsigned incr;
incr = (unsigned)round(newtop - brkend + 1, BYTESPERWORD);
if (brkincr > incr)
incr = brkincr;
if (setbrk(incr) == -1)
error(nospace);
}
unsigned char *
savstak()
{
assert(staktop == stakbot);
return(stakbot);
}
unsigned char *
endstak(unsigned char *argp) /* tidy up after `locstak' */
{
unsigned char *oldstak;
if (argp >= brkend)
growstak(argp);
*argp++ = 0;
oldstak = stakbot;
stakbot = staktop = (unsigned char *)round(argp, BYTESPERWORD);
if (staktop >= brkend)
growstak(staktop);
return(oldstak);
}
void
tdystak(unsigned char *x) /* try to bring stack back to x */
{
while ((unsigned char *)stakbsy > x)
{
free(stakbsy);
stakbsy = stakbsy->word;
}
staktop = stakbot = max(x, stakbas);
rmtemp(x);
}
void
stakchk(void)
{
if ((brkend - stakbas) > BRKINCR + BRKINCR)
setbrk(-BRKINCR);
}
unsigned char *
cpystak(x)
unsigned char *x;
{
return(endstak(movstrstak(x, locstak())));
}
unsigned char *
movstrstak(unsigned char *a, unsigned char *b)
{
do
{
if (b >= brkend)
growstak(b);
}
while (*b++ = *a++);
return(--b);
}
/*
* Copy s2 to s1, always copy n bytes.
* Return s1
*/
unsigned char *
memcpystak(unsigned char *s1, unsigned char *s2, int n)
{
unsigned char *os1 = s1;
while (--n >= 0) {
if (s1 >= brkend)
growstak(s1);
*s1++ = *s2++;
}
return (os1);
}
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