From: Denis Efremov <efremov@linux.com>
To: Joe Perches <joe@perches.com>, julia.lawall@inria.fr
Cc: cocci@systeme.lip6.fr, linux-kernel@vger.kernel.org,
Kees Cook <keescook@chromium.org>,
"Gustavo A . R . Silva" <gustavoars@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: checkpatch? (was: Re: [PATCH v3] coccinelle: misc: add uninitialized_var.cocci script)
Date: Wed, 2 Sep 2020 08:17:02 +0300 [thread overview]
Message-ID: <9894cd3d-a545-0daf-9e2d-c2b8d71356ef@linux.com> (raw)
In-Reply-To: <28483d2663213666503e0109230ac3eb742c8a52.camel@perches.com>
On 9/1/20 5:37 PM, Joe Perches wrote:
> On Tue, 2020-09-01 at 12:48 +0300, Denis Efremov wrote:
>> uninitialized_var() macro was removed from the sources [1] and
>> other warning-silencing tricks were deprecated [2]. The purpose of this
>> cocci script is to prevent new occurrences of uninitialized_var()
>> open-coded variants.
>
>> +(
>> +* T var =@p var;
>> +|
>> +* T var =@p *(&(var));
>> +|
>> +* var =@p var
>> +|
>> +* var =@p *(&(var))
>> +)
>
> Adding a checkpatch test might be a good thing too.
>
> ---
> scripts/checkpatch.pl | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index 149518d2a6a7..300b2659aab3 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -3901,6 +3901,17 @@ sub process {
> #ignore lines not being added
> next if ($line =~ /^[^\+]/);
>
> +# check for self assigments used to avoid compiler warnings
> +# e.g.: int foo = foo, *bar = NULL;
> +# struct foo bar = *(&(bar));
> + if ($line =~ /^\+\s*(?:$Declare)?([A-Za-z_][A-Za-z\d_]*)\s*=/) {
> + my $var = $1;
> + if ($line =~ /^\+\s*(?:$Declare)?$var\s*=\s*(?:$var|\*\s*\(?\s*&\s*\(?\s*$var\s*\)?\s*\)?)\s*[;,]/) {
> + WARN("SELF_ASSIGNMENT",
> + "Do not use self-assignments to avoid compiler warnings\n" . $herecurr);
> + }
> + }
> +
> # check for dereferences that span multiple lines
> if ($prevline =~ /^\+.*$Lval\s*(?:\.|->)\s*$/ &&
> $line =~ /^\+\s*(?!\#\s*(?!define\s+|if))\s*$Lval/) {
Looks good. I also faced this kind of assignments after declarations.
https://lkml.org/lkml/2020/8/31/85
I'm not sure if they are used to suppress compiler warnings, through.
Denis
next prev parent reply other threads:[~2020-09-02 5:17 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-11 21:01 [RFC PATCH] coccinelle: misc: add uninitialized_var.cocci script Denis Efremov
2020-08-29 19:36 ` Julia Lawall
2020-08-29 19:38 ` Joe Perches
2020-08-29 19:48 ` Julia Lawall
2020-08-29 20:13 ` Denis Efremov
2020-08-29 20:26 ` Julia Lawall
2020-09-01 7:15 ` [PATCH v2] " Denis Efremov
2020-09-01 9:06 ` Julia Lawall
2020-09-01 9:48 ` [PATCH v3] " Denis Efremov
2020-09-01 10:08 ` Julia Lawall
2020-09-01 14:37 ` checkpatch? (was: Re: [PATCH v3] coccinelle: misc: add uninitialized_var.cocci script) Joe Perches
2020-09-02 5:17 ` Denis Efremov [this message]
2020-09-05 17:18 ` [PATCH v3] coccinelle: misc: add uninitialized_var.cocci script Julia Lawall
2020-09-05 17:58 ` [PATCH] checkpatch: Warn on self-assignments Joe Perches
2020-09-10 19:51 ` Kees Cook
2020-09-10 21:35 ` Joe Perches
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