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* Re: [Cocci] [PATCH] coccinnelle: Remove ptr_ret script
       [not found] <20200107073629.325249-1-maxime@cerno.tech>
@ 2020-01-07 10:06 ` Julia Lawall
  2020-01-07 10:29   ` Wolfram Sang
  0 siblings, 1 reply; 2+ messages in thread
From: Julia Lawall @ 2020-01-07 10:06 UTC (permalink / raw)
  To: Maxime Ripard
  Cc: michal.lkml, Gilles.Muller, Tomi Valkeinen, Mark Brown,
	nicolas.palix, linux-kernel, Jani Nikula, Julia.Lawall,
	Thierry Reding, cocci



On Tue, 7 Jan 2020, Maxime Ripard wrote:

> The ptr_ret script script addresses a number of situations where we end up
> testing an error pointer, and if it's an error returning it, or return 0
> otherwise to transform it into a PTR_ERR_OR_ZERO call.
>
> So it will convert a block like this:
>
> if (IS_ERR(err))
>     return PTR_ERR(err);
>
> return 0;
>
> into
>
> return PTR_ERR_OR_ZERO(err);
>
> While this is technically correct, it has a number of drawbacks. First, it
> merges the error and success path, which will make it harder for a reviewer
> or reader to grasp.
>
> It's also more difficult to extend if we were to add some code between the
> error check and the function return, making the author essentially revert
> that patch before adding new lines, while it would have been a trivial
> addition otherwise for the rewiever.
>
> Therefore, since that script is only about cosmetic in the first place,
> let's remove it since it's not worth it.
>
> Cc: Jani Nikula <jani.nikula@linux.intel.com>
> Cc: Thierry Reding <thierry.reding@gmail.com>
> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
> Cc: Mark Brown <broonie@kernel.org>
> Signed-off-by: Maxime Ripard <maxime@cerno.tech>

Acked-by: Julia Lawall <julia.lawall@inria.fr>

> ---
>  scripts/coccinelle/api/ptr_ret.cocci | 97 ----------------------------
>  1 file changed, 97 deletions(-)
>  delete mode 100644 scripts/coccinelle/api/ptr_ret.cocci
>
> diff --git a/scripts/coccinelle/api/ptr_ret.cocci b/scripts/coccinelle/api/ptr_ret.cocci
> deleted file mode 100644
> index e76cd5d90a8a..000000000000
> --- a/scripts/coccinelle/api/ptr_ret.cocci
> +++ /dev/null
> @@ -1,97 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0-only
> -///
> -/// Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR
> -///
> -// Confidence: High
> -// Copyright: (C) 2012 Julia Lawall, INRIA/LIP6.
> -// Copyright: (C) 2012 Gilles Muller, INRIA/LiP6.
> -// URL: http://coccinelle.lip6.fr/
> -// Options: --no-includes --include-headers
> -//
> -// Keywords: ERR_PTR, PTR_ERR, PTR_ERR_OR_ZERO
> -// Version min: 2.6.39
> -//
> -
> -virtual context
> -virtual patch
> -virtual org
> -virtual report
> -
> -@depends on patch@
> -expression ptr;
> -@@
> -
> -- if (IS_ERR(ptr)) return PTR_ERR(ptr); else return 0;
> -+ return PTR_ERR_OR_ZERO(ptr);
> -
> -@depends on patch@
> -expression ptr;
> -@@
> -
> -- if (IS_ERR(ptr)) return PTR_ERR(ptr); return 0;
> -+ return PTR_ERR_OR_ZERO(ptr);
> -
> -@depends on patch@
> -expression ptr;
> -@@
> -
> -- (IS_ERR(ptr) ? PTR_ERR(ptr) : 0)
> -+ PTR_ERR_OR_ZERO(ptr)
> -
> -@r1 depends on !patch@
> -expression ptr;
> -position p1;
> -@@
> -
> -* if@p1 (IS_ERR(ptr)) return PTR_ERR(ptr); else return 0;
> -
> -@r2 depends on !patch@
> -expression ptr;
> -position p2;
> -@@
> -
> -* if@p2 (IS_ERR(ptr)) return PTR_ERR(ptr); return 0;
> -
> -@r3 depends on !patch@
> -expression ptr;
> -position p3;
> -@@
> -
> -* IS_ERR@p3(ptr) ? PTR_ERR(ptr) : 0
> -
> -@script:python depends on org@
> -p << r1.p1;
> -@@
> -
> -coccilib.org.print_todo(p[0], "WARNING: PTR_ERR_OR_ZERO can be used")
> -
> -
> -@script:python depends on org@
> -p << r2.p2;
> -@@
> -
> -coccilib.org.print_todo(p[0], "WARNING: PTR_ERR_OR_ZERO can be used")
> -
> -@script:python depends on org@
> -p << r3.p3;
> -@@
> -
> -coccilib.org.print_todo(p[0], "WARNING: PTR_ERR_OR_ZERO can be used")
> -
> -@script:python depends on report@
> -p << r1.p1;
> -@@
> -
> -coccilib.report.print_report(p[0], "WARNING: PTR_ERR_OR_ZERO can be used")
> -
> -@script:python depends on report@
> -p << r2.p2;
> -@@
> -
> -coccilib.report.print_report(p[0], "WARNING: PTR_ERR_OR_ZERO can be used")
> -
> -@script:python depends on report@
> -p << r3.p3;
> -@@
> -
> -coccilib.report.print_report(p[0], "WARNING: PTR_ERR_OR_ZERO can be used")
> --
> 2.24.1
>
>
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^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [Cocci] [PATCH] coccinnelle: Remove ptr_ret script
  2020-01-07 10:06 ` [Cocci] [PATCH] coccinnelle: Remove ptr_ret script Julia Lawall
@ 2020-01-07 10:29   ` Wolfram Sang
  0 siblings, 0 replies; 2+ messages in thread
From: Wolfram Sang @ 2020-01-07 10:29 UTC (permalink / raw)
  To: Julia Lawall
  Cc: michal.lkml, Gilles.Muller, Mark Brown, nicolas.palix,
	linux-kernel, Jani Nikula, Julia.Lawall, Tomi Valkeinen,
	Thierry Reding, Maxime Ripard, cocci

[-- Attachment #1.1: Type: text/plain, Size: 1532 bytes --]

On Tue, Jan 07, 2020 at 11:06:56AM +0100, Julia Lawall wrote:
> 
> 
> On Tue, 7 Jan 2020, Maxime Ripard wrote:
> 
> > The ptr_ret script script addresses a number of situations where we end up
> > testing an error pointer, and if it's an error returning it, or return 0
> > otherwise to transform it into a PTR_ERR_OR_ZERO call.
> >
> > So it will convert a block like this:
> >
> > if (IS_ERR(err))
> >     return PTR_ERR(err);
> >
> > return 0;
> >
> > into
> >
> > return PTR_ERR_OR_ZERO(err);
> >
> > While this is technically correct, it has a number of drawbacks. First, it
> > merges the error and success path, which will make it harder for a reviewer
> > or reader to grasp.
> >
> > It's also more difficult to extend if we were to add some code between the
> > error check and the function return, making the author essentially revert
> > that patch before adding new lines, while it would have been a trivial
> > addition otherwise for the rewiever.
> >
> > Therefore, since that script is only about cosmetic in the first place,
> > let's remove it since it's not worth it.
> >
> > Cc: Jani Nikula <jani.nikula@linux.intel.com>
> > Cc: Thierry Reding <thierry.reding@gmail.com>
> > Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
> > Cc: Mark Brown <broonie@kernel.org>
> > Signed-off-by: Maxime Ripard <maxime@cerno.tech>
> 
> Acked-by: Julia Lawall <julia.lawall@inria.fr>

Convincing patch description, good catch!

Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>


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_______________________________________________
Cocci mailing list
Cocci@systeme.lip6.fr
https://systeme.lip6.fr/mailman/listinfo/cocci

^ permalink raw reply	[flat|nested] 2+ messages in thread

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     [not found] <20200107073629.325249-1-maxime@cerno.tech>
2020-01-07 10:06 ` [Cocci] [PATCH] coccinnelle: Remove ptr_ret script Julia Lawall
2020-01-07 10:29   ` Wolfram Sang

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