# include	<ingres.h>
# include	<aux.h>
# include	<tree.h>
# include	<symbol.h>
# include	<sccs.h>

SCCSID(@(#)mapvar.c	8.1	12/31/84)

/*
**	MAPVAR -- construct variable maps for ROOT, AND, and AGHEAD nodes.
**	tl is a flag  which indicates if the target list should
**	be included in the mapping.  If tl = 0, it should; else it should not.
**
**	Trace Flags:
**		52
*/

mapvar(t, tl)
register QTREE	*t;
int		tl;
{
	register int	rmap, lmap;
	extern QTREE	*ckvar();

	if (t == NULL)
		return (NULL);

# ifdef xDTR3
	if (tTf(52, 0))
		printf("mapvar(%x) %c\n", t, t->sym.type);
# endif xDTR3

	switch (t->sym.type)
	{
	  case ROOT:
	  case AND:
	  case AGHEAD:
		/* map the right side */
		t->sym.value.sym_root.rvarm = rmap = mapvar(t->right, tl);

		/* map the left side or else use existing values */
		if (tl == 0)
		{
			t->sym.value.sym_root.lvarm = lmap = mapvar(t->left, tl);
			t->sym.value.sym_root.lvarc = bitcnt(lmap);
		}
		else
			lmap = t->sym.value.sym_root.lvarm;

		/* form map of both sides */
		rmap |= lmap;

		/* compute total var count */
		t->sym.value.sym_root.tvarc = bitcnt(rmap);

		return (rmap);

	  case VAR:
		if ((t = ckvar(t))->sym.value.sym_var.valptr)
			return (NULL);	/* var is a constant */
		return (01 << t->sym.value.sym_var.varno);
	}

	/* node is not a VAR, AND, ROOT, or AGHEAD */
	return (mapvar(t->left, tl) | mapvar(t->right, tl));
}