linux-kernel - Re: [PATCH v2] coccinelle: misc: add minmax script

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Date:   Fri, 19 Feb 2021 12:07:39 +0300
From:   Denis Efremov <efremov@...ux.com>
To:     Julia Lawall <julia.lawall@...ia.fr>
Cc:     cocci@...teme.lip6.fr, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] coccinelle: misc: add minmax script

Sorry for wrong thread, I'll resend v2 to the right one.

Denis

On 2/19/21 12:05 PM, Denis Efremov wrote:
> Check for opencoded min(), max() implementations.
> 
> Signed-off-by: Denis Efremov <efremov@...ux.com>
> ---
> 
> Changes in v2:
>  - <... ...> instead of ... when any
>  - org mode reports fixed
>  - patch rule to drop excessive ()
> 
>  scripts/coccinelle/misc/minmax.cocci | 224 +++++++++++++++++++++++++++
>  1 file changed, 224 insertions(+)
>  create mode 100644 scripts/coccinelle/misc/minmax.cocci
> 
> diff --git a/scripts/coccinelle/misc/minmax.cocci b/scripts/coccinelle/misc/minmax.cocci
> new file mode 100644
> index 000000000000..61d6b61fd82c
> --- /dev/null
> +++ b/scripts/coccinelle/misc/minmax.cocci
> @@ -0,0 +1,224 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +///
> +/// Check for opencoded min(), max() implementations.
> +/// Generated patches sometimes require adding a cast to fix compile warning.
> +/// Warnings/patches scope intentionally limited to a function body.
> +///
> +// Confidence: Medium
> +// Copyright: (C) 2021 Denis Efremov ISPRAS
> +// Options: --no-includes --include-headers
> +//
> +// Keywords: min, max
> +//
> +
> +
> +virtual report
> +virtual org
> +virtual context
> +virtual patch
> +
> +@...x depends on !patch@
> +identifier func;
> +expression x, y;
> +binary operator cmp = {>, >=};
> +position p;
> +@@
> +
> +func(...)
> +{
> +	<...
> +*	x cmp@p y ? x : y
> +	...>
> +}
> +
> +@...xif depends on !patch@
> +identifier func;
> +expression x, y;
> +expression max_val;
> +binary operator cmp = {>, >=};
> +position p;
> +@@
> +
> +func(...)
> +{
> +	<...
> +*	if (x cmp@p y) {
> +*		max_val = x;
> +*	} else {
> +*		max_val = y;
> +*	}
> +	...>
> +}
> +
> +@...n depends on !patch@
> +identifier func;
> +expression x, y;
> +binary operator cmp = {<, <=};
> +position p;
> +@@
> +
> +func(...)
> +{
> +	<...
> +*	x cmp@p y ? x : y
> +	...>
> +}
> +
> +@...nif depends on !patch@
> +identifier func;
> +expression x, y;
> +expression min_val;
> +binary operator cmp = {<, <=};
> +position p;
> +@@
> +
> +func(...)
> +{
> +	<...
> +*	if (x cmp@p y) {
> +*		min_val = x;
> +*	} else {
> +*		min_val = y;
> +*	}
> +	...>
> +}
> +
> +@...x depends on patch@
> +identifier func;
> +expression x, y;
> +binary operator cmp = {>=, >};
> +position p;
> +@@
> +
> +func@p(...)
> +{
> +	<...
> +-	x cmp y ? x : y
> ++	max(x, y)
> +	...>
> +}
> +
> +@...xif depends on patch@
> +identifier func;
> +expression x, y;
> +expression max_val;
> +binary operator cmp = {>=, >};
> +position p;
> +@@
> +
> +func@p(...)
> +{
> +	<...
> +-	if (x cmp y) {
> +-		max_val = x;
> +-	} else {
> +-		max_val = y;
> +-	}
> ++	max_val = max(x, y);
> +	...>
> +}
> +
> +@...n depends on patch@
> +identifier func;
> +expression x, y;
> +binary operator cmp = {<=, <};
> +position p;
> +@@
> +
> +func@p(...)
> +{
> +	<...
> +-	x cmp y ? x : y
> ++	min(x, y)
> +	...>
> +}
> +
> +@...nif depends on patch@
> +identifier func;
> +expression x, y;
> +expression min_val;
> +binary operator cmp = {<=, <};
> +position p;
> +@@
> +
> +func@p(...)
> +{
> +	<...
> +-	if (x cmp y) {
> +-		min_val = x;
> +-	} else {
> +-		min_val = y;
> +-	}
> ++	min_val = min(x, y);
> +	...>
> +}
> +
> +@...ends on (pmax || pmaxif || pmin || pminif)@
> +identifier func;
> +expression x, y;
> +position p;
> +// FIXME: Coccinelle consumes all available ram and
> +// and timeouts on every file.
> +// position p = { pmin.p, pminif.p, pmax.p, pmaxif.p };
> +@@
> +
> +func@p(...)
> +{
> +	<...
> +(
> +-	(min((x), (y)))
> ++	min(x, y)
> +|
> +-	(max((x), (y)))
> ++	max(x, y)
> +)
> +	...>
> +}
> +
> +@...ipt:python depends on report@
> +p << rmax.p;
> +@@
> +
> +coccilib.report.print_report(p[0], "WARNING opportunity for max()")
> +
> +@...ipt:python depends on org@
> +p << rmax.p;
> +@@
> +
> +coccilib.org.print_todo(p[0], "WARNING opportunity for max()")
> +
> +@...ipt:python depends on report@
> +p << rmaxif.p;
> +@@
> +
> +coccilib.report.print_report(p[0], "WARNING opportunity for max()")
> +
> +@...ipt:python depends on org@
> +p << rmaxif.p;
> +@@
> +
> +coccilib.org.print_todo(p[0], "WARNING opportunity for max()")
> +
> +@...ipt:python depends on report@
> +p << rmin.p;
> +@@
> +
> +coccilib.report.print_report(p[0], "WARNING opportunity for min()")
> +
> +@...ipt:python depends on org@
> +p << rmin.p;
> +@@
> +
> +coccilib.org.print_todo(p[0], "WARNING opportunity for min()")
> +
> +@...ipt:python depends on report@
> +p << rminif.p;
> +@@
> +
> +coccilib.report.print_report(p[0], "WARNING opportunity for min()")
> +
> +@...ipt:python depends on org@
> +p << rminif.p;
> +@@
> +
> +coccilib.org.print_todo(p[0], "WARNING opportunity for min()")
>