Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
IronPort-HdrOrdr: =?us-ascii?q?A9a23=3AFqbHTaq7g8Ab45sZyXkxT8saV5t/L9V00zAX?=
 =?us-ascii?q?/kB9WHVpW+afkN2jm+le8BfyhioYVn1Io6H4BICrR3TA+ZlppbQAJLvKZniFhE?=
 =?us-ascii?q?KEJJxvhLGC/xTOACv7n9Q26Y5Bd7F5E8D5ClJ35PyKmDWQM9Fl+9Wf9bDtuOG2?=
 =?us-ascii?q?9RhQZCVLT40l0AtjEAacFSRNNWp7LL40DoCV6MYChxfIQxQqR/+2DHUEQOTPzu?=
 =?us-ascii?q?ej/K7OWhIICwUq7wODl1qThILSKBSA2wdbbjUn+9wf2FLYmA/07LjLiZ+G4yLc?=
 =?us-ascii?q?zGPa4tB3n9bs27J4daqxo/USQw+Ati+YIKBaf7WDuXQNu+Go81Y2gLD30nMdFv?=
 =?us-ascii?q?U2z3vQe22vyCGdvDXI4XIW8H/l0l+EkRLY0KnEeA4=3D?=
Date:   Tue, 13 Apr 2021 11:56:20 +0200 (CEST)
From:   Julia Lawall <julia.lawall@inria.fr>
To:     Fabio Aiuto <fabioaiuto83@gmail.com>
cc:     gregkh@linuxfoundation.org, joe@perches.com,
        linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: Re: cocci script hints request
In-Reply-To: <20210413090400.GA5477@agape.jhs>
Message-ID: <alpine.DEB.2.22.394.2104131154100.2872@hadrien>
References: <20210413090400.GA5477@agape.jhs>
User-Agent: Alpine 2.22 (DEB 394 2020-01-19)
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Precedence: bulk


On Tue, 13 Apr 2021, Fabio Aiuto wrote:

> Hi,
>
> I would like to improve the following coccinelle script:
>
> @@
> expression a, fmt;
> expression list var_args;
> @@
>
> -       DBG_871X_LEVEL(a, fmt, var_args);
> +       printk(fmt, var_args);
>
> I would  replace the DBG_871X_LEVEL macro with printk, but
> I can't find a way to add KERN_* constant prefix to the fmt
> argument in the + code line. If i try this
>
> @@
> expression a, fmt;
> expression list var_args;
> @@
>
> -       DBG_871X_LEVEL(a, fmt, var_args);
> +       printk(KERN_DEBUG fmt, var_args);
>
> plus: parse error:
>   File "../test.cocci", line 94, column 20, charpos = 1171
>   around = 'fmt',
>   whole content = +	printk(KERN_DEBUG fmt, var_args);
>
> how could I do this?

Although I certainly agree with Greg, I'll answer the question from a
technical point of view.

I'm not sure that that kind of compound string is supported for a
metavariable.  It is possible to get around this problem using a python
script.  If you ever need to do this for a better reason, you can take a
look at demos/pythontococci.cocci in the Coccinelle source code
distribution.

julia