Re: [PATCH] cocci: simplify check for trivial format strings

From: René Scharfe <l.s.r@web.de>
Date: Feb 2, 2018, 18:49 UTC
Message-ID: <0df36d0a-6066-05c4-d471-f25a76ce301c@web.de>
In-Reply-To: <CAM0VKjnoux1CBq-HvzRW14hXZyviG_z_Rv-qv7d0kakh18zXcw@mail.gmail.com>

Am 02.02.2018 um 15:34 schrieb SZEDER Gábor:

Show 25 quoted lines

> On Thu, Feb 1, 2018 at 7:56 PM, René Scharfe <l.s.r@web.de> wrote:
>> 353d84c537 (coccicheck: make transformation for strbuf_addf(sb, "...")
>> more precise) added a check to avoid transforming calls with format
>> strings which contain percent signs, as that would change the result.
>> It uses embedded Python code for that.  Simplify this rule by using the
>> regular expression matching operator instead.
>>
>> Signed-off-by: Rene Scharfe <l.s.r@web.de>
>> ---
>> Inspired by the Coccinelle package in Debian experimental, which lost
>> support for Python for some reason.  Tested only with that version
>> (1.0.6.deb-3) and Debian testing's 1.0.4.deb-3+b3.
> 
> FWIW, it appears to be working fine with Coccinelle version
> 1.0.0~rc19.deb-3 running on Travis CI.
> Applied it on top of 'rs/strbuf-cocci-workaround' currently at cd9a4b6d9
> (cocci: use format keyword instead of a literal string, 2018-01-19)
> along with an other patch to show the resulting suggestions in
> '.../*.cocci.patch' files, and the results look fine:
> 
>    https://travis-ci.org/szeder/git/jobs/336573242#L1466
> 
> and are the same as without this patch:
> 
>    https://travis-ci.org/szeder/git/jobs/336257153#L1466

It's good to hear that it doesn't error out, but there is no code in master that would trigger a good or bad transformation. It should propose a patch for calls like this:

	strbuf_addf(sb, "just a string, better use strbuf_addstr");

... but leave those examples here alone:

	strbuf_addf(sb, "200%% more percent signs");
	strbuf_addf(sb, "error: %m");

René