source: trunk/minix/lib/ack/libm2/confarray.c@ 16

/*
  (c) copyright 1988 by the Vrije Universiteit, Amsterdam, The Netherlands.
  See the copyright notice in the ACK home directory, in the file "Copyright".
*/

/*
  Module:       runtime support for conformant arrays
  Author:       Ceriel J.H. Jacobs
  Version:      $Header: /cvsup/minix/src/lib/ack/libm2/confarray.c,v 1.1 2005/10/10 15:27:46 beng Exp $
*/
#include <m2_traps.h>

#ifndef EM_WSIZE
#define EM_WSIZE _EM_WSIZE
#define EM_PSIZE _EM_PSIZE
#endif

#if EM_WSIZE==EM_PSIZE
typedef unsigned pcnt;
#else
typedef unsigned long pcnt;
#endif

struct descr {
        char *addr;
        int low;
        unsigned int highminlow;
        unsigned int size;
};

static struct descr *descrs[10];
static struct descr **ppdescr = descrs;

pcnt
new_stackptr(pdscr, a)
        struct descr *pdscr;
{
        register struct descr *pdescr = pdscr;
        pcnt size = (((pdescr->highminlow + 1) * pdescr->size +
                                (EM_WSIZE - 1)) & ~(EM_WSIZE - 1));

        if (ppdescr >= &descrs[10]) {
                /* to many nested traps + handlers ! */
                TRP(M2_TOOMANY);
        }
        *ppdescr++ = pdescr;
        if ((char *) &a - (char *) &pdscr > 0) {
                /* stack grows downwards */
                return - size;
        }
        return size;
}

copy_array(pp, a)
        char *pp;
{
        register char *p = pp;
        register char *q;
        register pcnt sz;
        char dummy;

        ppdescr--;
        sz = ((*ppdescr)->highminlow + 1) * (*ppdescr)->size;
        
        if ((char *) &a - (char *) &pp > 0) {
                (*ppdescr)->addr = q = (char *) &a;
        }
        else    (*ppdescr)->addr = q = (char *) &a - 
                        ((sz + (EM_WSIZE - 1)) & ~ (EM_WSIZE - 1));

        while (sz--) *q++ = *p++;
}