GSoC - Code Formatting and Style Checking for RTEMS score

Fri Jun 4 14:46:52 UTC 2021

On Fri, Jun 4, 2021 at 12:24 AM Ida Delphine <idadelm at gmail.com> wrote:

> Hello everyone,
>
> I applied the configuration Sebastian used and ran clang-format on
> cpukit/score/src/threadqenque.c and so far these are the differences I
> could notice...
> Below are some example areas in the code you can spot the differences:
>
>    - In line 68, the ")" at the end of the parameter list needs to be in
>    a new row, but this doesn't seem to be supported in clang-format.
>
> If I understand correctly, clang-format does not like:

https://git.rtems.org/rtems/tree/cpukit/score/src/threadqenqueue.c

which has the first parameter on its one line but wants the first parameter
after the open parenthesis?

The RTEMS style would seem to correspond to AlignAfterOpenBracket being
set to AlwaysBreak

>
>    - In line 142, if the function call is split into multiple rows, the
>    ");" should always be in a new row.
>
> Having the closing parenthesis on its own line may end up being something
we have to change the RTEMS style on. I do not see an option in their
documentation to do this. Unfortunate, since I like the symmetry between
braces and parentheses.

 Could you file an issue with them and/or ask a question the appropriate
mailing list? Please cc Gedara and me. Give them an example. Maybe
we are missing something.

>
>    - In line 201-202, we can see that the "*" of the pointers are not
>    aligned to the right.
>
>
This seems to be the issue Gedare mentioned which might have a patch.
Follow up on that.

But I think we had previously discussed this as a point we may have to
concede and change RTEMS style on.

> You can check out the formatted file here - https://pastebin.com/nDBrSSCP
>

Is it just the website or are blank line differences? It may just be an
illusion. I think the spacing between the numbered lines is greater
than in the git view. Just odd.

--joel

>
>
> On Tue, Jun 1, 2021 at 5:36 PM Gedare Bloom <gedare at rtems.org> wrote:
>
>> On Mon, May 31, 2021 at 2:59 PM Ida Delphine <idadelm at gmail.com> wrote:
>> >
>> > Hi Gedare,
>> >
>> > With regards to your comment on discord on me looking for a tool that
>> works on both patches and source files, it turns out clang-format has that
>> functionality already. Here's what I found -
>> https://clang.llvm.org/docs/ClangFormat.html#script-for-patch-reformatting
>> >
>> > Does it match what you have in mind?
>> >
>> Yes. I think we would want to not use the `-i` option but instead pass
>> through and check the changes. I don't think we should rewrite the
>> patches themselves, but instead we want to use a tool that can be used
>> to check and approve the style of submitted patches. You might need to
>> write a modified version of the clang-format-diff.py to use as a
>> "checker" with ability to provide exceptions to the rules.
>>
>> Gedare
>>
>> > On Thu, May 13, 2021 at 3:49 PM Gedare Bloom <gedare at rtems.org> wrote:
>> >>
>> >> On Wed, May 12, 2021 at 2:18 PM Ida Delphine <idadelm at gmail.com>
>> wrote:
>> >> >
>> >> > Hello everyone,
>> >> > Still waiting for some feedback :)
>> >> >
>> >> > Cheers,
>> >> > Ida.
>> >> >
>> >> > On Mon, 10 May 2021, 5:59 am Ida Delphine, <idadelm at gmail.com>
>> wrote:
>> >> >>
>> >> >> Hello everyone,
>> >> >> Went through some previous emails and it turns out Sebastian
>> already came up with a configuration for clang format which works well for
>> RTEMS except for the fact that some configurations haven't been implemented
>> into clang-format yet. Using
>> >> >>
>> >> >> AlignConsecutiveDeclarations: false
>> >> >> PointerAlignment: Right
>> >> >>
>> >> >> Doesn't seem to work.
>> >> >> For example in the cpukit/score/src/threadq.c file, something like
>> >> >>
>> >> >> RTEMS_STATIC_ASSERT(
>> >> >> offsetof( Thread_queue_Syslock_queue, Queue.name )
>> >> >> == offsetof( struct _Thread_queue_Queue, _name ),
>> >> >> THREAD_QUEUE_SYSLOCK_QUEUE_NAME
>> >> >> );
>> >> >>
>> >> >> RTEMS_STATIC_ASSERT(
>> >> >> sizeof( Thread_queue_Syslock_queue )
>> >> >> == sizeof( struct _Thread_queue_Queue ),
>> >> >> THREAD_QUEUE_SYSLOCK_QUEUE_SIZE
>> >> >> );
>> >> >>
>> >> >> #if defined(RTEMS_SMP)
>> >> >> void _Thread_queue_Do_acquire_critical(
>> >> >> Thread_queue_Control *the_thread_queue,
>> >> >> ISR_lock_Context *lock_context
>> >> >> )
>> >> >> {
>> >> >> _Thread_queue_Queue_acquire_critical(
>> >> >> &the_thread_queue->Queue,
>> >> >> &the_thread_queue->Lock_stats,
>> >> >> lock_context
>> >> >> );
>> >> >>
>> >> >> becomes this after using the given configuration
>> >> >>
>> >> >> RTEMS_STATIC_ASSERT(sizeof(Thread_queue_Syslock_queue) ==
>> >> >> sizeof(struct _Thread_queue_Queue),
>> >> >> THREAD_QUEUE_SYSLOCK_QUEUE_SIZE);
>> >> >>
>> >> >> #if defined(RTEMS_SMP)
>> >> >> void _Thread_queue_Do_acquire_critical(Thread_queue_Control
>> *the_thread_queue,
>> >> >> ISR_lock_Context *lock_context) {
>> >> >> _Thread_queue_Queue_acquire_critical(
>> >> >> &the_thread_queue->Queue, &the_thread_queue->Lock_stats,
>> lock_context);
>> >> >>
>> >> >> Everything seems manageable except for this alignment issue...
>> >> >> This also throws more light on the changes using clang-format (
>> https://lists.rtems.org/pipermail/devel/2018-December/024145.html)
>> >> >>
>> >> I think we're willing to concede the pointer alignment. However, it
>> >> would be worth spending some time to see if
>> >> https://reviews.llvm.org/D27651 can be made to work. The current state
>> >> of the code would need to be compared to the patch on that review
>> >> board.
>> >>
>> >> Beyond that, documenting the clang-format options to use is next, and
>> >> then identifying a plan how to invoke clang-format during a git
>> >> workflow is needed.
>> >>
>> >> >> On Thu, May 6, 2021 at 8:05 PM Joel Sherrill <joel at rtems.org>
>> wrote:
>> >> >>>
>> >> >>>
>> >> >>>
>> >> >>> On Thu, May 6, 2021 at 12:47 PM Christian Mauderer <
>> oss at c-mauderer.de> wrote:
>> >> >>>>
>> >> >>>> Hello Ida and Gedare,
>> >> >>>>
>> >> >>>> On 06/05/2021 06:26, Gedare Bloom wrote:
>> >> >>>> > hi Ida,
>> >> >>>> >
>> >> >>>> > On Wed, May 5, 2021 at 3:21 PM Ida Delphine <idadelm at gmail.com>
>> wrote:
>> >> >>>> >>
>> >> >>>> >> Hello everyone,
>> >> >>>> >>
>> >> >>>> >> Regarding this project (https://devel.rtems.org/ticket/3860)
>> I went with clang-format as we all agreed. I have tested it on some "score"
>> files and it made some changes which I don't think are very much in line
>> with the RTEMS coding style. However, it wasn't really clear if we will
>> chage the RTEMS coding style or try to make changes to clang-format to fit
>> the style.
>> >> >>>> >> Please will love to know the best option.
>> >> >>>> >>
>> >> >>>> > We will likely need to consider our choices carefully. If we
>> can find
>> >> >>>> > a suitably close style that is already well-supported by clang,
>> and
>> >> >>>> > get consensus from the maintainers on a change, then that might
>> be the
>> >> >>>> > best route forward.
>> >> >>>>
>> >> >>>> +1
>> >> >>>>
>> >> >>>> > I think the first thing to do is take the examples
>> >> >>>> > that have been shown by Sebastian that are "close" but not quite
>> >> >>>> > perfect, and identify the cases where they differ with RTEMS
>> style in
>> >> >>>> > order to present for discussion here. If consensus can't be
>> reached to
>> >> >>>> > change the style, then we would need to have a plan for how to
>> improve
>> >> >>>> > the existing tools for what we have.
>> >> >>>>
>> >> >>>> I also found the following tool quite useful to play with the
>> clang
>> >> >>>> style config:
>> >> >>>>
>> >> >>>> https://zed0.co.uk/clang-format-configurator/
>> >> >>>>
>> >> >>>> Maybe it can help a bit to find out what certain options mean.
>> >> >>>>
>> >> >>>> >
>> >> >>>> > However, I think there is interest in doing less work on the
>> tool
>> >> >>>> > side, and more work on how to integrate it into our workflows
>> better.
>> >> >>>>
>> >> >>>> +1
>> >> >>>
>> >> >>>
>> >> >>> I agree with all of this from the student perspective. But we will
>> have
>> >> >>> to come to some agreement on a machine producible format to
>> >> >>> be able to use the integration. A report on what doesn't match
>> would
>> >> >>> give us something to chew on while Ida works the integration.
>> >> >>>
>> >> >>> --joel
>> >> >>>>
>> >> >>>>
>> >> >>>> >
>> >> >>>> >> Cheers,
>> >> >>>> >> Ida.
>> >> >>>> >> _______________________________________________
>> >> >>>> >> devel mailing list
>> >> >>>> >> devel at rtems.org
>> >> >>>> >> http://lists.rtems.org/mailman/listinfo/devel
>> >> >>>> > _______________________________________________
>> >> >>>> > devel mailing list
>> >> >>>> > devel at rtems.org
>> >> >>>> > http://lists.rtems.org/mailman/listinfo/devel
>> >> >>>> >
>> >> >>>> _______________________________________________
>> >> >>>> devel mailing list
>> >> >>>> devel at rtems.org
>> >> >>>> http://lists.rtems.org/mailman/listinfo/devel
>>
>
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