Question

I was wondering how people handle return statements in a function. I have a method that allocates some memory but has a return false; statement when a function goes wrong. this statement is located about half way through the function so my memory is leaked if that function fails. This isn’t the only return …; statement I have in this function. What would stackoverflow recommend doing to clean up the code in a function with a few return statements in it?

if( true == OpenFtpConnection() )
{
    AfxMessageBox( _T( "Connection to internet and ftp server found" ) );

    // set the directory to where the xml file lives
    if( false == FtpSetCurrentDirectory( m_ftpHandle, _T(_FTP_XML_LOCATION) ) )
        return false;

    HINTERNET xmlHandle = NULL;
    WIN32_FIND_DATA fileData;
    SYSTEMTIME fileWriteTime;
    xmlHandle = FtpFindFirstFile( m_ftpHandle, _T("TPCFeed.xml"), &fileData, INTERNET_FLAG_RELOAD, 0 );
    if( NULL == xmlHandle )
        return false;
    else
    {
        // get the write time of the ftp file
        FileTimeToSystemTime( &fileData.ftLastWriteTime, &fileWriteTime );

        // get the write time of the local file
        HANDLE localFileHandle = NULL;
        localFileHandle = CreateFile( _T(_XML_FILENAME_PATH), FILE_READ_ATTRIBUTES,
                                 FILE_SHARE_READ, NULL, OPEN_EXISTING,
                                 NULL, NULL );
        if( INVALID_HANDLE_VALUE == localFileHandle )
        {
            AfxMessageBox( _T( "opening file failed, file not found" ) );
            return false;
        }
        else
        {
            CloseHandle( localFileHandle );
        }


        // close the FtpFindFirstFile() handle
        InternetCloseHandle( xmlHandle );
    }


    // download xml file to disk
    //if( false == FtpGetFile( m_ftpHandle, _T("TPCFeed.xml"), _T(_XML_FILENAME_PATH), FALSE, 
    //                       FILE_ATTRIBUTE_NORMAL, FTP_TRANSFER_TYPE_BINARY, 0 ) )
    //  return false;

}
else
{
    AfxMessageBox( _T( "No Connection to internet or ftp server found" ) );
    return false;
}
if( true == CloseFtpConnection() )
    AfxMessageBox( _T( "Connection to internet closed" ) );
else
    AfxMessageBox( _T( "Connection to internet not closed" ) );

Answer 1

Clarity is the most important thing. Many times, having multiple return points can make the program flow less obvious and thus more prone to bugs; but on the other hand, sometimes early returns are quite obvious; their meaning and purpose is clear. So I tend to avoid any hard rules about that.

You might get more mileage if you actually post the code you want to clean up though.