Re: [PATCH] fix a code style in drivers/char/virtio_console.c

From: Steven Liu
Date: Tue May 18 2010 - 02:48:15 EST


okay, i see, thanks for your regards :)

2010/5/18 Amit Shah <amit.shah@xxxxxxxxxx>:
> Hello,
>
> On (Tue) May 18 2010 [13:41:29], Steven Liu wrote:
>> Hi, Amit,
>>
>>     if 'err' initialised in this path, it needn't do err = -ENOMEM
>> after,isn't it?
>
> What I mean is if we later add some code that just does:
>
>        if (err)
>                goto fail;
>
> then 'ret' can be -ENOMEM, as it was initialised to, which would be
> fine. But if a later patch adds something like:
>
> +       ret = -EIO;
> +       err = ...
> +       if (err)
> +               goto fail;
> +
>        err = ...
>        if (err)
>                goto fail;
>
> In this case, the 2nd if() would now return EIO instead of ENOMEM as
> earlier.
>
> Also, this style of coding can prevent uninitialised usage of 'ret', eg:
>
>
>        int ret;
>
>        if (err)
>                goto fail;
>
> fail:
>        return ret;
>
> In this case, the compiler will warn about 'ret' being used
> uninitialised.
>
> This is just a coding style issue. I had initially coded it the way your
> patch does, but Rusty asked me to change that and I like this new style
> better: there's less scope for surprises.
>
>                Amit
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/