1/*
2 * Copyright (C) 2017 Oracle.  All rights reserved.
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/*
19 * This basically stores when a pointer is stored as a struct member.
20 *
21 */
22
23#include "smatch.h"
24#include "smatch_slist.h"
25#include "smatch_extra.h"
26
27static int my_id;
28
29static void match_assign(struct expression *expr)
30{
31	struct expression *left, *right;
32	mtag_t right_tag, left_tag;
33	int right_offset, left_offset;
34	sval_t sval;
35
36	if (expr->op != '=')
37		return;
38
39	left = strip_expr(expr->left);
40	right = strip_expr(expr->right);
41
42	if (!type_is_ptr(get_type(right)))
43		return;
44	if (!get_implied_value(right, &sval))
45		return;
46	if (sval_cmp(sval, valid_ptr_min_sval) < 0 ||
47	    sval_cmp(sval, valid_ptr_max_sval) > 0)
48		return;
49	right_tag = sval.uvalue & ~MTAG_OFFSET_MASK;
50	right_offset = sval.uvalue & MTAG_OFFSET_MASK;
51
52	if (!expr_to_mtag_offset(left, &left_tag, &left_offset) ||
53	    left_offset >= MTAG_OFFSET_MASK)
54		return;
55
56	sql_insert_mtag_map(left_tag, left_offset, right_tag, right_offset);
57}
58
59void register_mtag_map(int id)
60{
61	my_id = id;
62
63	add_hook(&match_assign, ASSIGNMENT_HOOK);
64	add_hook(&match_assign, GLOBAL_ASSIGNMENT_HOOK);
65}
66