unp.c

Go to the documentation of this file.

/* $Header: /opt/proj/minix/cvsroot/src/lib/ack/libp/unp.c,v 1.1 2005/10/10 15:27:47 beng Exp $ */
/*
 * (c) copyright 1983 by the Vrije Universiteit, Amsterdam, The Netherlands.
 *
 *          This product is part of the Amsterdam Compiler Kit.
 *
 * Permission to use, sell, duplicate or disclose this software must be
 * obtained in writing. Requests for such permissions may be sent to
 *
 *      Dr. Andrew S. Tanenbaum
 *      Wiskundig Seminarium
 *      Vrije Universiteit
 *      Postbox 7161
 *      1007 MC Amsterdam
 *      The Netherlands
 *
 */

/* Author: J.W. Stevenson */

#include        <pc_err.h>

extern          _trp();

#define assert(x)       /* nothing */

#ifndef EM_WSIZE
#define EM_WSIZE _EM_WSIZE
#endif

struct descr {
        int     low;
        int     diff;
        int     size;
};

_unp(ad,zd,i,ap,zp,noext) int i; struct descr *ad,*zd; char *ap,*zp; int noext; {

        if (zd->diff > ad->diff ||
                        (i -= ad->low) < 0 ||
                        (i+zd->diff) > ad->diff)
                _trp(EUNPACK);
        ap += (i * ad->size);
        i = (zd->diff + 1) * zd->size;
        if (zd->size == 1) {
                int *aptmp = (int *) ap;
                assert(ad->size == EM_WSIZE);
                while (--i >= 0)
                        if (noext) *aptmp++ = *zp++ & 0377;
                        else *aptmp++ = *zp++;
#if EM_WSIZE > 2
        } else if (zd->size == 2) {
                int *aptmp = (int *) ap;
                short *zptmp = (short *) zp;
                assert(ad->size == EM_WSIZE);
                while (--i >= 0)
                        if (noext) *aptmp++ = *zptmp++ & 0177777;
                        else *aptmp++ = *zptmp++;
#endif
        } else {
                assert(ad->size == zd->size);
                while (--i >= 0)
                        *ap++ = *zp++;
        }
}

---