GSoC - Code Formatting and Style Checking for RTEMS score

Tue Jun 15 13:45:19 UTC 2021

Hello everyone,

For this project, I am supposed to write a git pre-commit hook in which
runs over a patch checking if the style matches that of RTEMS and aborts in
case it doesn't. From the screenshot below you can see what happens in case
the style doesn't match in a patch. The commit doesn't happen and it
outputs the diff first showing what it looked like when committed and how
the patch's format is supposed to look like. It does not directly format
the patch. I am yet to do more tests to be sure there are no bugs but will
like to get some feedback if there is a better way it should look like.

[image: hooks-output.png]

On Fri, Jun 4, 2021 at 10:50 PM Ida Delphine <idadelm at gmail.com> wrote:

> Okay. I will do that.
>
> On Fri, 4 Jun 2021, 10:48 pm Gedare Bloom, <gedare at rtems.org> wrote:
>
>> On Fri, Jun 4, 2021 at 2:57 PM Ida Delphine <idadelm at gmail.com> wrote:
>> >
>> > Okay, I will take a look.
>> >
>> > Regarding me asking a question in the appropriate clang-format mailing
>> list should it be just regarding the parentheses and braces being aligned?
>> >
>> That would be the right question to ask, if you can't find a way to
>> align the closing parenthesis.
>>
>> You might also follow-up that old thread related to alignment of the
>> pointers.
>>
>> > On Fri, Jun 4, 2021 at 8:41 PM Joel Sherrill <joel at rtems.org> wrote:
>> >>
>> >>
>> >>
>> >> On Fri, Jun 4, 2021 at 12:39 PM Gedare Bloom <gedare at rtems.org> wrote:
>> >>>
>> >>> On Fri, Jun 4, 2021 at 8:47 AM Joel Sherrill <joel at rtems.org> wrote:
>> >>> >
>> >>> >
>> >>> >
>> >>> > 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.
>> >>> >
>> >>> That's just the pastebin having more vertical padding between
>> consecutive lines.
>> >>
>> >>
>> >> That's what I thought but it did make the code look funny.
>> >>
>> >> Ida/Gedare.. does this mean there are only 3 style mismatch issues? Or
>> only
>> >> three in this file?
>> >>
>> >> Probably should try a few more files and see if there are other
>> discrepancies.
>> >>
>> >> And obviously work on the integration/automation of using the tools. :)
>> >>
>> >> --joel
>> >>
>> >>>
>> >>>
>> >>> > --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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