1/*
2 * Copyright (C) 2011 Dan Carpenter.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version 2
7 * of the License, or (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, see http://www.gnu.org/copyleft/gpl.txt
16 */
17
18#include "smatch.h"
19#include "smatch_slist.h"
20
21static int my_id;
22
23static void match_return(struct expression *ret_value)
24{
25	struct expression *expr;
26	char *macro;
27
28	if (!ret_value)
29		return;
30	expr = ret_value;
31	if (ret_value->type != EXPR_PREOP || ret_value->op != '-')
32		return;
33
34	macro = get_macro_name(expr->unop->pos);
35	if (macro && !strcmp(macro, "PTR_ERR")) {
36		sm_warning("returning -%s()", macro);
37		return;
38	}
39
40	if (!option_spammy)
41		return;
42
43	expr = get_assigned_expr(ret_value->unop);
44	if (!expr)
45		return;
46	if (expr->type != EXPR_CALL)
47		return;
48
49	sm_warning("should this return really be negated?");
50}
51
52void check_return_negative_var(int id)
53{
54	if (option_project != PROJ_KERNEL)
55		return;
56
57	my_id = id;
58	add_hook(&match_return, RETURN_HOOK);
59}
60