1/*
2 * Copyright (C) 2010 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
20static int my_id;
21static struct symbol *func_sym;
22
23STATE(argument);
24STATE(ok);
25
26static void set_ok(struct sm_state *sm, struct expression *mod_expr)
27{
28	if (sm->state != &ok)
29		set_state(my_id, sm->name, sm->sym, &ok);
30}
31
32static void match_function_def(struct symbol *sym)
33{
34	struct symbol *arg;
35
36	func_sym = sym;
37	FOR_EACH_PTR(func_sym->ctype.base_type->arguments, arg) {
38		if (!arg->ident) {
39			continue;
40		}
41		set_state(my_id, arg->ident->name, arg, &argument);
42	} END_FOR_EACH_PTR(arg);
43}
44
45static int get_arg_num(struct expression *expr)
46{
47	struct smatch_state *state;
48	struct symbol *arg;
49	struct symbol *this_arg;
50	int i;
51
52	expr = strip_expr(expr);
53	if (expr->type != EXPR_SYMBOL)
54		return -1;
55	this_arg = expr->symbol;
56
57	state = get_state_expr(my_id, expr);
58	if (!state || state != &argument)
59		return -1;
60
61	i = 0;
62	FOR_EACH_PTR(func_sym->ctype.base_type->arguments, arg) {
63		if (arg == this_arg)
64			return i;
65		i++;
66	} END_FOR_EACH_PTR(arg);
67
68	return -1;
69}
70
71static void match_is_err(const char *fn, struct expression *expr, void *unused)
72{
73	struct expression *arg;
74	int arg_num;
75
76	arg = get_argument_from_call_expr(expr->args, 0);
77	arg_num = get_arg_num(arg);
78	if (arg_num < 0)
79		return;
80	sm_msg("info: expects ERR_PTR %d", arg_num);
81}
82
83void check_expects_err_ptr(int id)
84{
85	if (option_project != PROJ_KERNEL)
86		return;
87	if (!option_info)
88		return;
89
90	my_id = id;
91	add_hook(&match_function_def, FUNC_DEF_HOOK);
92	add_modification_hook(my_id, &set_ok);
93	add_function_hook("IS_ERR", &match_is_err, NULL);
94}
95