/*
 * Copyright (C) 2021 Oracle.
 *
 * 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, see http://www.gnu.org/copyleft/gpl.txt
 */

#include "smatch.h"
#include "smatch_slist.h"

static int my_id;

static void check_for_EPROBE_DEFER(struct expression *expr)
{
	sval_t sval;
	char *macro;

	if (!expr || expr->type != EXPR_PREOP || expr->op != '-')
		return;

	expr = expr->unop;
	if (!get_value(expr, &sval) || sval.value != 517)
		return;

	macro = get_macro_name(expr->pos);
	if (!macro || strcmp(macro, "EPROBE_DEFER") != 0)
		return;
	sm_warning("returning EPROBE_DEFER from non probe() function");
}

static void match_assign(struct expression *expr)
{
	/* "ret = ERR_PTR(-EPROBE_DEFER)" generates a fake assignment so
	 * that is covered here.
	 */
	check_for_EPROBE_DEFER(expr->right);
}

static void match_return(struct expression *expr)
{
	check_for_EPROBE_DEFER(expr);
}

void check_EPROBE_DEFER(int id)
{
	my_id = id;

	if (option_project != PROJ_KERNEL)
		return;

	add_hook(&match_assign, ASSIGNMENT_HOOK);
	add_hook(&match_return, RETURN_HOOK);
}