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;
21
22static void match_stmt(struct statement *stmt)
23{
24	struct expression *expr;
25
26	if (stmt->type != STMT_EXPRESSION)
27		return;
28	expr = stmt->expression;
29	if (!expr)
30		return;
31	switch(expr->type) {
32	case EXPR_PREOP:
33		if (expr->op == '!')
34			break;
35		if (expr->op == '~')
36			break;
37	case EXPR_POSTOP:
38	case EXPR_STATEMENT:
39	case EXPR_ASSIGNMENT:
40	case EXPR_CALL:
41	case EXPR_CONDITIONAL:
42	case EXPR_SELECT:
43	case EXPR_CAST:
44	case EXPR_FORCE_CAST:
45	case EXPR_COMMA:
46		return;
47	}
48	if (in_expression_statement())
49		return;
50	sm_warning("statement has no effect %d", expr->type);
51}
52
53void check_no_effect(int id)
54{
55	my_id = id;
56	add_hook(&match_stmt, STMT_HOOK);
57}
58