/*
 *  SPL - The SPL Programming Language
 *  Copyright (C) 2004, 2005  Clifford Wolf <clifford@clifford.at>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *  rccheck.c: Checking the reference counters
 */

#include "spl.h"

static inline int rcc_abs(int v)
{
	return v < 0 ? v * -1 : v;
}

static int rcc_node(int rcc_pass, struct spl_node *node, int *rc_list, int *rc_count)
{
	struct spl_node_sub *s;

	int size = 1;
	if ( !node ) return 0;

	switch ( rcc_pass )
	{
	case 0:
		/* init and get size for rc_list */
		if (node->dump_tag == 1) return 0;
		node->dump_tag = 1;
		break;
	case 1:
		/* assign numbers */
		if (node->dump_tag != 1) return 0;
		node->dump_tag = ++(*rc_count) + 16;
		break;
	case 2:
		/* store reference counters */
		rc_list[rcc_abs(node->dump_tag)-16]++;
		if (node->dump_tag < 0) return 0;
		node->dump_tag *= -1;
		break;
	case 3:
		/* check reference counters */
		if (!node->dump_tag) return 0;

		if ( rc_list[rcc_abs(node->dump_tag)-16] != node->ref_counter )
			spl_report(SPL_REPORT_RUNTIME, 0,
				"Refcount-Check: %p: should be %d but is %d.\n",
				node, rc_list[rcc_abs(node->dump_tag)-16],
				node->ref_counter);

		node->dump_tag = 0;
		break;
	}

	size += rcc_node(rcc_pass, node->ctx, rc_list, rc_count);
	size += rcc_node(rcc_pass, node->cls, rc_list, rc_count);

	for (s = node->subs_begin; s; s = s->next)
		size += rcc_node(rcc_pass, s->node, rc_list, rc_count);

	return size;
}

static int rcc_task(int rcc_pass, struct spl_task *task, int *rc_list, int *rc_count)
{
	int size = 1;
	size += rcc_node(rcc_pass, task->ctx, rc_list, rc_count);

	struct spl_node_stack *s = task->stack;
	while (s) {
		size += rcc_node(rcc_pass, s->node, rc_list, rc_count);
		s = s->next;
	}

	return size;
}

static int rcc_vm(int rcc_pass, struct spl_vm *vm, int *rc_list, int *rc_count)
{
	int size = 1;
	size += rcc_node(rcc_pass, vm->root, rc_list, rc_count);

	struct spl_task *t = vm->task_list;
	while (t) {
		size += rcc_task(rcc_pass, t, rc_list, rc_count);
		t = t->next;
	}

	return size;
}

void spl_rccheck(struct spl_vm *vm)
{
	int size = rcc_vm(0, vm, 0, 0);
	int rc_list[size], rc_count = 0;

	for (int i=0; i<size; i++) rc_list[i] = 0;
	rcc_vm(1, vm, rc_list, &rc_count);
	rcc_vm(2, vm, rc_list, &rc_count);
	rcc_vm(3, vm, rc_list, &rc_count);
}