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* [Cocci] Adjusting SmPL script “ptr_ret.cocci”?
@ 2019-09-07 14:54 Markus Elfring
  2019-09-07 16:05 ` Julia Lawall
  0 siblings, 1 reply; 4+ messages in thread
From: Markus Elfring @ 2019-09-07 14:54 UTC (permalink / raw)
  To: Coccinelle, kernel-janitors
  Cc: Kate Stewart, Michal Marek, Greg Kroah-Hartman, Nicolas Palix,
	LKML, Allison Randal

Hello,

I have taken another look at a known script for the semantic patch language.
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/scripts/coccinelle/api/ptr_ret.cocci?id=1e3778cb223e861808ae0daccf353536e7573eed#n3

I got the impression that duplicate SmPL code can be reduced here.
So I tried the following approach out.

…
@depends on patch@
expression ptr;
@@
(
(
- if (IS_ERR(ptr)) return PTR_ERR(ptr); else return 0;
|
- if (IS_ERR(ptr)) return PTR_ERR(ptr); return 0;
)
+ return PTR_ERR_OR_ZERO(ptr);
|
- (IS_ERR(ptr) ? PTR_ERR(ptr) : 0)
+ PTR_ERR_OR_ZERO(ptr)
)
…


Unfortunately, I got the following information then for a test transformation.

elfring@Sonne:~/Projekte/Linux/next-patched> spatch -D patch scripts/coccinelle/api/ptr_ret.cocci drivers/spi/spi-gpio.c
…
29: no available token to attach to


It seems that the Coccinelle software “1.0.7-00218-gf284bf36” does not like
the addition of the shown return statement after a nested SmPL disjunction.
But the following SmPL code variant seems to work as expected.


…
@depends on patch@
expression ptr;
@@
(
- if (IS_ERR(ptr)) return PTR_ERR(ptr); else return 0;
+ return PTR_ERR_OR_ZERO(ptr);
|
- if (IS_ERR(ptr)) return PTR_ERR(ptr); return 0;
+ return PTR_ERR_OR_ZERO(ptr);
|
- (IS_ERR(ptr) ? PTR_ERR(ptr) : 0)
+ PTR_ERR_OR_ZERO(ptr)
)
…


How do you think about to reduce subsequent SmPL rules also according to
a possible recombination of affected implementation details?

Regards,
Markus
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^ permalink raw reply	[flat|nested] 4+ messages in thread
* Re: [Cocci] Adjusting SmPL script “ptr_ret.cocci”?
  2019-09-07 14:54 [Cocci] Adjusting SmPL script “ptr_ret.cocci”? Markus Elfring
@ 2019-09-07 16:05 ` Julia Lawall
  2019-09-07 16:20   ` Markus Elfring
  2019-09-07 16:40   ` [Cocci] [PATCH] Coccinelle: Reduce rules in SmPL script “ptr_ret.cocci” Markus Elfring
  0 siblings, 2 replies; 4+ messages in thread
From: Julia Lawall @ 2019-09-07 16:05 UTC (permalink / raw)
  To: Markus Elfring
  Cc: Kate Stewart, Michal Marek, Greg Kroah-Hartman, Nicolas Palix,
	kernel-janitors, LKML, Coccinelle, Allison Randal

[-- Attachment #1: Type: text/plain, Size: 1894 bytes --]



On Sat, 7 Sep 2019, Markus Elfring wrote:

> Hello,
>
> I have taken another look at a known script for the semantic patch language.
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/scripts/coccinelle/api/ptr_ret.cocci?id=1e3778cb223e861808ae0daccf353536e7573eed#n3
>
> I got the impression that duplicate SmPL code can be reduced here.
> So I tried the following approach out.
>
> …
> @depends on patch@
> expression ptr;
> @@
> (
> (
> - if (IS_ERR(ptr)) return PTR_ERR(ptr); else return 0;
> |
> - if (IS_ERR(ptr)) return PTR_ERR(ptr); return 0;
> )
> + return PTR_ERR_OR_ZERO(ptr);
> |
> - (IS_ERR(ptr) ? PTR_ERR(ptr) : 0)
> + PTR_ERR_OR_ZERO(ptr)
> )
> …
>
>
> Unfortunately, I got the following information then for a test transformation.
>
> elfring@Sonne:~/Projekte/Linux/next-patched> spatch -D patch scripts/coccinelle/api/ptr_ret.cocci drivers/spi/spi-gpio.c
> …
> 29: no available token to attach to
>
>
> It seems that the Coccinelle software “1.0.7-00218-gf284bf36” does not like
> the addition of the shown return statement after a nested SmPL disjunction.
> But the following SmPL code variant seems to work as expected.
>
>
> …
> @depends on patch@
> expression ptr;
> @@
> (
> - if (IS_ERR(ptr)) return PTR_ERR(ptr); else return 0;
> + return PTR_ERR_OR_ZERO(ptr);
> |
> - if (IS_ERR(ptr)) return PTR_ERR(ptr); return 0;
> + return PTR_ERR_OR_ZERO(ptr);
> |
> - (IS_ERR(ptr) ? PTR_ERR(ptr) : 0)
> + PTR_ERR_OR_ZERO(ptr)
> )
> …
>
>
> How do you think about to reduce subsequent SmPL rules also according to
> a possible recombination of affected implementation details?

There is not going to be any change with respect to this issue.  It's fine
when replacing one statement by another, but introduces complexity when
removing something more complex.  And there's not point to have something
that works in only one special case.

julia

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^ permalink raw reply	[flat|nested] 4+ messages in thread
* Re: [Cocci] Adjusting SmPL script “ptr_ret.cocci”?
  2019-09-07 16:05 ` Julia Lawall
@ 2019-09-07 16:20   ` Markus Elfring
  2019-09-07 16:40   ` [Cocci] [PATCH] Coccinelle: Reduce rules in SmPL script “ptr_ret.cocci” Markus Elfring
  1 sibling, 0 replies; 4+ messages in thread
From: Markus Elfring @ 2019-09-07 16:20 UTC (permalink / raw)
  To: Julia Lawall, Coccinelle, kernel-janitors
  Cc: Kate Stewart, Michal Marek, Greg Kroah-Hartman, Nicolas Palix,
	LKML, Allison Randal

>> How do you think about to reduce subsequent SmPL rules also according to
>> a possible recombination of affected implementation details?
>
> There is not going to be any change with respect to this issue.

I am curious if the software situation will be reconsidered any further
under other circumstances.


> It's fine when replacing one statement by another, but introduces complexity
> when removing something more complex.

Thanks for such information.


> And there's not point to have something that works in only one special case.

Will corresponding software development concerns be eventually discussed
a bit more?

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

^ permalink raw reply	[flat|nested] 4+ messages in thread
* [Cocci] [PATCH] Coccinelle: Reduce rules in SmPL script “ptr_ret.cocci”
  2019-09-07 16:05 ` Julia Lawall
  2019-09-07 16:20   ` Markus Elfring
@ 2019-09-07 16:40   ` Markus Elfring
  1 sibling, 0 replies; 4+ messages in thread
From: Markus Elfring @ 2019-09-07 16:40 UTC (permalink / raw)
  To: Julia Lawall, Coccinelle, kernel-janitors, Gilles Muller,
	Masahiro Yamada, Michal Marek, Nicolas Palix
  Cc: Kate Stewart, Greg Kroah-Hartman, LKML, Thomas Gleixner, Allison Randal

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sat, 7 Sep 2019 18:30:32 +0200

This SmPL script contains duplicate code.
Thus reduce it to the required source code search functionality
by the means of the semantic patch language.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 scripts/coccinelle/api/ptr_ret.cocci | 61 +++++-----------------------
 1 file changed, 10 insertions(+), 51 deletions(-)

diff --git a/scripts/coccinelle/api/ptr_ret.cocci b/scripts/coccinelle/api/ptr_ret.cocci
index e76cd5d90a8a..f4b1ce4a06d0 100644
--- a/scripts/coccinelle/api/ptr_ret.cocci
+++ b/scripts/coccinelle/api/ptr_ret.cocci
@@ -20,44 +20,28 @@ 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
+|
+* if@p1 (IS_ERR(ptr)) return PTR_ERR(ptr); return 0;
+|
+* IS_ERR@p1(ptr) ? PTR_ERR(ptr) : 0
+)

 @script:python depends on org@
 p << r1.p1;
@@ -65,33 +49,8 @@ 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")
--
2.23.0

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^ permalink raw reply related	[flat|nested] 4+ messages in thread
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2019-09-07 14:54 [Cocci] Adjusting SmPL script “ptr_ret.cocci”? Markus Elfring
2019-09-07 16:05 ` Julia Lawall
2019-09-07 16:20   ` Markus Elfring
2019-09-07 16:40   ` [Cocci] [PATCH] Coccinelle: Reduce rules in SmPL script “ptr_ret.cocci” Markus Elfring

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