/*
 * Copyright (C) 2010 Dan Carpenter.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see http://www.gnu.org/copyleft/gpl.txt
 */

#include "smatch.h"

static int my_id;

static void match_stmt(struct statement *stmt)
{
        struct expression *expr;

        if (stmt->type != STMT_EXPRESSION)
                return;
        expr = stmt->expression;
        if (!expr)
                return;
        switch(expr->type) {
        case EXPR_PREOP:
                if (expr->op == '!')
                        break;
                if (expr->op == '~')
                        break;
        case EXPR_POSTOP:
        case EXPR_STATEMENT:
        case EXPR_ASSIGNMENT:
        case EXPR_CALL:
        case EXPR_CONDITIONAL:
        case EXPR_SELECT:
        case EXPR_CAST:
        case EXPR_FORCE_CAST:
        case EXPR_COMMA:
                return;
        }
        if (in_expression_statement())
                return;
        sm_warning("statement has no effect %d", expr->type);
}

void check_no_effect(int id)
{
        my_id = id;
        add_hook(&match_stmt, STMT_HOOK);
}