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 
20 static int my_id;
21 
match_assign(struct expression * expr)22 static void match_assign(struct expression *expr)
23 {
24 	const char *macro;
25 	sval_t max_left, max_right;
26 	char *name;
27 
28 	if (expr->op != '=')
29 		return;
30 
31 	macro = get_macro_name(expr->pos);
32 	if (!macro)
33 		return;
34 	if (strcmp(macro, "min_t"))
35 		return;
36 
37 	if (!get_absolute_max(expr->left, &max_left))
38 		return;
39 	if (!get_absolute_max(expr->right, &max_right))
40 		return;
41 
42 	if (sval_cmp(max_left, max_right) >= 0)
43 		return;
44 
45 	name = expr_to_str(expr->right);
46 	sm_warning("min_t truncates here '%s' (%s vs %s)", name, sval_to_str(max_left), sval_to_str(max_right));
47 	free_string(name);
48 }
49 
check_min_t(int id)50 void check_min_t(int id)
51 {
52 	my_id = id;
53 	if (option_project != PROJ_KERNEL)
54 		return;
55 	add_hook(&match_assign, ASSIGNMENT_HOOK);
56 }
57