Clang format config for Weston

[Harish Krupo]

Hi Simon,

Simon Ser <contact at emersion.fr> writes:

> On Thursday, March 14, 2019 12:20 PM, Harish Krupo <harish.krupo.kps at intel.com> wrote:
>
>> Hi Pekka,
>>
>> Pekka Paalanen ppaalanen at gmail.com writes:
>>
>> > On Thu, 14 Mar 2019 16:01:08 +0530
>> > Harish Krupo harish.krupo.kps at intel.com wrote:
>> >
>> > > Hi,
>> > > I have written a clang format file based on this example [1], to
>> > > match the coding style here [2]. Does the below config look okay or
>> > > should something be changed?
>> > > If people are interested, I can open a MR for this. This could also be
>> > > used in the CI to warn/abort if a patch isn't according to the coding
>> > > style.
>> > > The config:
>> > > BasedOnStyle: LLVM
>> > > IndentWidth: 8
>> > > TabWidth: 8
>> > > UseTab: Always
>> > > BreakBeforeBraces: Linux
>> > > AllowShortIfStatementsOnASingleLine: false
>> > > IndentCaseLabels: false
>> > > AlwaysBreakAfterReturnType: TopLevel
>> > > [1] https://clang.llvm.org/docs/ClangFormatStyleOptions.html#examples
>> > > [2] https://gitlab.freedesktop.org/wayland/weston/blob/master/CONTRIBUTING.md#coding-style
>> >
>> > Hi Harish,
>> > I guess that depends on how different that is from the existing code
>> > base style. Seeing the warning list generated for the existing code
>> > would tell a lot, I doubt it would be empty.
>>
>> Okay, I see what you mean. Running clang format on
>> libweston/gl-renderer.c does generate a few false positives. Some of
>> them could be corrected by setting other config options.
>
> An issue with clang-format is that getting a perfect config file is
> really tedious (and sometimes impossible).
>
> I'll try improving it a little.

Sure. Please do :)

>
>> > Is the LLVM style something guaranteed to not change?
>>
>> I am not sure about this :(
>
> We can always copy-pasta the LLVM style.
>
>> > Using it in CI might be an attractive idea, but I wonder if it would
>> > result in many false warnings. Some aspects of coding style are always
>> > somewhat vague and need to adapt to the code at hand to look nice to a
>> > human rather than follow some rigorous rules. If it leaves such things
>> > as is and checks only those that should follow rigorous rules, that
>> > would be nice.
>>
>> All the config options that Clang-format uses to format code is given in
>> [1]. It leaves the rest to the user. We would have to define all (at
>> least most) of those options for weston if we want to use this with the
>> CI. Consequence of doing this would make the BasedOnStyle: LLVM option
>> unneeded.
>>
>> Thank you
>> Regards
>> Harish Krupo
>>
>> [1] https://clang.llvm.org/docs/ClangFormatStyleOptions.html