develooper Front page | perl.perl5.porters | Postings from December 2018

Re: regexec.c: LGTM analysis warns about two comparisons, butweactually need them

Thread Previous | Thread Next
From:
Karl Williamson
Date:
December 6, 2018 19:54
Subject:
Re: regexec.c: LGTM analysis warns about two comparisons, butweactually need them
Message ID:
9e2ae7d8-c6a5-79df-a95b-e846c5587536@khwilliamson.com
On 12/6/18 6:30 AM, Dominic Hargreaves wrote:
> On Thu, Dec 06, 2018 at 08:20:50AM -0500, James E Keenan wrote:
>> On 12/6/18 3:16 AM, Tony Cook wrote:
>>> On Wed, Dec 05, 2018 at 10:28:54PM -0500, James E Keenan wrote:
>>>> Here is a case where the LGTM.com analysis of the Perl 5 source code
>>>> produces results that are at first plausible but ultimately incorrect.
>>>>
>>>> The following section of regexec.c is cited (https://lgtm.com/projects/g/Perl/perl5/alerts/?mode=tree&ruleFocus=2154840804)
>>>> with the warning-level alert "Comparison result is always the same":
>>>
>>> This was discussed in #133686, the comparison needs to stay to allow
>>> for local configuration of larger values of NUM_ANYOF_CODE_POINTS.
>>>
>>
>> Would it be okay if I inserted a comment to that effect into regexec.c so
>> that we don't stumble upon this again in the future?

I have pushed a branch with this commit that changes those numbers to 
symbols to make things clear

https://perl5.git.perl.org/perl.git/commitdiff/ef5a8af164793929880381dcf36b727440050d44
> 
> That sounds sensible to me regardless of systems like LGTM. You *could*
> even use the LGTM suppression syntax (in addition to a human-readable
> explanation); this would mean that if in the future we can implement
> /* */ suppression comments in LGTM, they would be recognised.
> 
> You can watch this topic for more updates on that feature request:
> 
> https://discuss.lgtm.com/t/rfe-support-for-supression-comments-in-comment-blocks/1364
> 
> In case you weren't aware, if you think that a certain type of alert
> will *never* be interesting for a given code-base you can disable it
> entirely in .lgtm.yml:
> 
> https://lgtm.com/help/lgtm/showing-hiding-query-results
> 
> Cheers,
> Dominic.
> 

Thread Previous | Thread Next


nntp.perl.org: Perl Programming lists via nntp and http.
Comments to Ask Bjørn Hansen at ask@perl.org | Group listing | About