From: "René Scharfe" <l.s.r@web.de>
To: Markus Elfring <Markus.Elfring@web.de>,
Junio C Hamano <gitster@pobox.com>
Cc: git@vger.kernel.org
Subject: Re: coccinelle: adjustments for array.cocci?
Date: Thu, 14 Nov 2019 17:41:21 +0100 [thread overview]
Message-ID: <53346d52-e096-c651-f70a-ce6ca4d82ff9@web.de> (raw)
In-Reply-To: <ba5d609a-16ea-d7e9-66e6-19aab94b2acd@web.de>
Am 14.11.19 um 14:15 schrieb Markus Elfring:
> You mentioned “failures”. - I became curious then if corresponding software
> development challenges can be clarified a bit more.
Let's try to restore/repeat the pertinent paragraph, with context and
attribution:
Am 13.11.19 um 03:11 schrieb Junio C Hamano:
> René Scharfe <l.s.r@web.de> writes:
>> Am 12.11.19 um 16:08 schrieb Markus Elfring:
>>>
>>> Do you find the following code variant (for the semantic patch language) also useful?
>>>
>>> memcpy(
>>> ( ptr, E, n *
>>> - sizeof(*(ptr))
>>> + sizeof(T)
>>> | arr, E, n *
>>> - sizeof(*(arr))
>>> + sizeof(T)
>>> | E, ptr, n *
>>> - sizeof(*(ptr))
>>> + sizeof(T)
>>> | E, arr, n *
>>> - sizeof(*(arr))
>>> + sizeof(T)
>>> )
>>> )
>
>> This reduces duplication in the semantic patch, which is nice. I think
>> I tried something like that at the time, but found that it failed to
>> produce some of the cases in 921d49be86 ("use COPY_ARRAY for copying
>> arrays", 2019-06-15) for some reason.
> Thanks for mentioning.
>
> I too recall that seemingly redundant entries were noticed during
> the review and at least back then removing the seemingly redundant
> ones caused failures in rewriting.
You can see for yourself by:
1. applying the patch at the bottom to implement your suggested change,
2. running "git show 921d49be86 | patch -p1 -R" to undo 921d49be86,
3. running "make contrib/coccinelle/array.cocci.patch",
4. running "patch -p1 <contrib/coccinelle/array.cocci.patch",
5. running "git diff".
If the new version of array.cocci is equivalent to the current one then
that last step should show no difference. For me, "git diff --stat"
reports, however:
contrib/coccinelle/array.cocci | 30 ++++++++++++++----------------
fast-import.c | 2 +-
packfile.c | 4 ++--
pretty.c | 4 ++--
4 files changed, 19 insertions(+), 21 deletions(-)
The changes in array.cocci are expected of course, but the others
indicate that the new version missed transformations that the current
version generated.
René
-- >8 --
diff --git a/contrib/coccinelle/array.cocci b/contrib/coccinelle/array.cocci
index 46b8d2ee11..e7bcbefcc1 100644
--- a/contrib/coccinelle/array.cocci
+++ b/contrib/coccinelle/array.cocci
@@ -12,27 +12,25 @@ T *ptr;
T[] arr;
expression E, n;
@@
+ memcpy(
(
- memcpy(ptr, E,
-- n * sizeof(*(ptr))
-+ n * sizeof(T)
- )
+ ptr, E, n *
+- sizeof(*(ptr))
++ sizeof(T)
|
- memcpy(arr, E,
-- n * sizeof(*(arr))
-+ n * sizeof(T)
- )
+ arr, E, n *
+- sizeof(*(arr))
++ sizeof(T)
|
- memcpy(E, ptr,
-- n * sizeof(*(ptr))
-+ n * sizeof(T)
- )
+ E, ptr, n *
+- sizeof(*(ptr))
++ sizeof(T)
|
- memcpy(E, arr,
-- n * sizeof(*(arr))
-+ n * sizeof(T)
- )
+ E, arr, n *
+- sizeof(*(arr))
++ sizeof(T)
)
+ )
@@
type T;
next prev parent reply other threads:[~2019-11-14 16:41 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-12 15:08 coccinelle: adjustments for array.cocci? Markus Elfring
2019-11-12 18:37 ` René Scharfe
2019-11-13 2:11 ` Junio C Hamano
2019-11-13 8:49 ` Markus Elfring
2019-11-14 2:03 ` Junio C Hamano
2019-11-14 13:15 ` Markus Elfring
2019-11-14 16:41 ` René Scharfe [this message]
2019-11-14 17:14 ` Markus Elfring
2019-11-14 17:46 ` René Scharfe
2019-11-15 11:11 ` git-coccinelle: " Markus Elfring
2019-11-15 14:20 ` Markus Elfring
2019-11-15 18:50 ` Markus Elfring
2019-11-16 1:00 ` [Cocci] " Julia Lawall
2019-11-16 6:57 ` Markus Elfring
2019-11-16 8:29 ` Markus Elfring
2019-11-16 17:57 ` Julia Lawall
2019-11-16 18:29 ` Markus Elfring
2019-11-15 20:37 ` coccinelle: " Markus Elfring
2019-11-16 21:13 ` René Scharfe
2019-11-17 7:56 ` Markus Elfring
2019-11-17 13:40 ` René Scharfe
2019-11-17 18:19 ` Markus Elfring
2019-11-19 19:14 ` René Scharfe
2019-11-19 20:21 ` Markus Elfring
2019-11-21 19:01 ` René Scharfe
2019-11-16 16:33 ` Markus Elfring
2019-11-16 21:38 ` René Scharfe
2019-11-17 8:19 ` Markus Elfring
2019-11-17 13:40 ` René Scharfe
2019-11-17 18:36 ` Markus Elfring
2019-11-19 19:15 ` René Scharfe
2019-11-18 16:10 ` [PATCH] coccinelle: improve array.cocci Markus Elfring
2019-11-19 19:15 ` René Scharfe
2019-11-20 9:01 ` Markus Elfring
2019-11-21 19:02 ` René Scharfe
2019-11-21 19:44 ` Markus Elfring
2019-11-22 15:29 ` SZEDER Gábor
2019-11-22 16:17 ` Markus Elfring
2019-11-22 5:54 ` [PATCH] " Junio C Hamano
2019-11-22 7:34 ` Markus Elfring
2020-01-25 8:23 ` Markus Elfring
-- strict thread matches above, loose matches on Subject: below --
2019-11-12 15:08 coccinelle: adjustments for array.cocci? Markus Elfring
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: http://vger.kernel.org/majordomo-info.html
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=53346d52-e096-c651-f70a-ce6ca4d82ff9@web.de \
--to=l.s.r@web.de \
--cc=Markus.Elfring@web.de \
--cc=git@vger.kernel.org \
--cc=gitster@pobox.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://80x24.org/mirrors/git.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).