/*
 * Copyright (C) 2009 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
 */

/*
 * In wine you aren't allowed to compare file handles with 0,
 * only with INVALID_HANDLE_VALUE.
 *
 */

#include "smatch.h"

static int my_id;

STATE(filehandle);
STATE(oktocheck);

/* originally:
 *  "(?:CreateFile|CreateMailslot|CreateNamedPipe|FindFirstFile(?:Ex)?|OpenConsole|SetupOpenInfFile|socket)[AW]?"
 *
 */
static const char *filehandle_funcs[] = {
        "CreateFile",
        "CreateMailslot",
        "CreateNamedPipe",
        "FindFirstFile",
        "FindFirstFileEx",
        "OpenConsole",
        "SetupOpenInfFile",
        "socket",
        NULL,
};

static void ok_to_use(struct sm_state *sm, struct expression *mod_expr)
{
        if (sm->state != &oktocheck)
                set_state(my_id, sm->name, sm->sym, &oktocheck);
}

static void match_returns_handle(const char *fn, struct expression *expr,
                             void *info)
{
        char *left_name = NULL;
        struct symbol *left_sym;

        left_name = expr_to_var_sym(expr->left, &left_sym);
        if (!left_name || !left_sym)
                goto free;
        set_state_expr(my_id, expr->left, &filehandle);
free:
        free_string(left_name);
}

static void match_condition(struct expression *expr)
{
        if (expr->type == EXPR_ASSIGNMENT)
                match_condition(expr->left);

        if (get_state_expr(my_id, expr) == &filehandle) {
                char *name;

                name = expr_to_var(expr);
                sm_error("comparing a filehandle against zero '%s'", name);
                set_state_expr(my_id, expr, &oktocheck);
                free_string(name);
        }
}

void check_wine_filehandles(int id)
{
        int i;

        if (option_project != PROJ_WINE)
                return;

        my_id = id;
        for (i = 0; filehandle_funcs[i]; i++) {
                add_function_assign_hook(filehandle_funcs[i],
                                         &match_returns_handle, NULL);
        }
        add_hook(&match_condition, CONDITION_HOOK);
        add_modification_hook(my_id, ok_to_use);
}