/*
 * Copyright (c) 1988,1991 by Sozobon, Limited.  Author: Joseph M Treat
 *
 * Permission is granted to anyone to use this software for any purpose
 * on any computer system, and to redistribute it freely, with the
 * following restrictions:
 * 1) No charge may be made other than reasonable charges for reproduction.
 * 2) Modified versions must be clearly marked as such.
 * 3) The authors are not responsible for any harmful consequences
 *    of using this software, even if they result from defects in it.
 */

#include "jas.h"
#include "proto.h"

extern long newdot;
extern int line;

extern SYM dot;

CLIST  *t_head = (CLIST *) NULL,
       *d_head = (CLIST *) NULL;
CLIST  *txtptr = (CLIST *) NULL,
       *datptr = (CLIST *) NULL;

void bufhead(void)
{
       txtptr = t_head;
       datptr = d_head;
       if ( txtptr )
               txtptr->inx = 0;
       if ( datptr )
               datptr->inx = 0;
}

CBUF * cget (unsigned short seg)
{
       register CLIST *xc, *oxc;

       xc = seg == TXT ? txtptr : datptr;
       if ( xc == (CLIST *) NULL )
               return (CBUF *) NULL;

       if ( xc->inx >= xc->cnt ) {
               /*
                * the current CLIST is used up
                */
               oxc = xc;
               xc = xc->next;
               *( seg == TXT ? &txtptr : &datptr ) = xc;
               free( (char *) oxc );
               if (! xc ) {
                       return (CBUF *) NULL;
               }
               xc->inx = 0;
       }
       return &xc->cblock[xc->inx++];
}

CBUF *
generate(short n, short act, long val, SYM *psym)
{
       register CLIST *xc;
       register CBUF *cp;

       if ( act == GENRELOC && psym == (SYM *) NULL )
               act = GENVALUE;

/* out for now ...
       fprintf( stderr, "generate( [%x], %d, %d, %lx, ",
                                               dot.flags, n, act, val );
       if ( psym )
               fprintf( stderr, "\"%.8s\" )\n", psym->name );
       else
               fprintf( stderr, "\"\" )\n" );
... */

       switch ( dot.flags ) {
       case TXT:
               if ( txtptr == (CLIST *) NULL )
                       txtptr = t_head = ALLO(CLIST);
               xc = txtptr;
               break;
       case BSS:
               if ( act != GENVALUE || val != 0L || psym != (SYM *) NULL )
                       Yerror( "Attempt to initialize bss" );
               newdot += n / 8;
#ifdef GENERIC
               return;
#else
               return NULL;
#endif
       case DAT:
               if ( datptr == (CLIST *) NULL )
                       datptr = d_head = ALLO(CLIST);
               xc = datptr;
               break;
       }

       if ( xc->cnt == CBLEN || (act == GENBRNCH && xc->cnt >= CBLEN-1) ) {
               xc->next = ALLO(CLIST);
               xc = xc->next;
               *( dot.flags == TXT ? &txtptr : &datptr ) = xc;
               xc->cnt = 0;
               xc->next = (CLIST *) NULL;
       }

       cp = &xc->cblock[xc->cnt++];

       if ( psym )
               psym->flags |= DEFINED;
       cp->action = act == GENBRNCH ? GENSTMT : act;
       cp->nbits = n;
       cp->value.value = val;
       cp->value.psym = psym;
#ifdef USE_LINE
       cp->line = line;
#endif

       newdot += n / 8;
       return cp;
}

VOID
zeros( n )
       register long n;
{
       if ( newdot & 1 ) {
               generate( 8, GENVALUE, 0L, (SYM *) NULL );
               n--;
       }
/* out for now ...
       for (; n >= 4; n -= 4 )
               generate(32, GENVALUE, 0L, (SYM *) NULL );
... */
       for (; n >= 2; n -= 2 )
               generate( 16, GENVALUE, 0L, (SYM *) NULL );
       if ( n )
               generate( 8, GENVALUE, 0L, (SYM *) NULL );
}