Re: [PATCH] .gitignore: ignore temporary files from 'bear'

Re: [PATCH] .gitignore: ignore temporary files from 'bear'

[Nathan Chancellor]

Hi Brendan,

On Wed, Aug 27, 2025 at 08:59:43AM +0000, Brendan Jackman wrote:
> Bear [0] is a tool for generating compile_commands.json. For Kbuild,
> Bear is not useful, since Kbuild already generates the necessary info
> and that can be converted to compile_commands.json by
> gen_compile_commads.py.
> 
> However, for code in tools/, it's handy. For example, this command
> updates compile_commands.json so that clangd code navigation will also
> work for the VMA unit tests:
> 
> 	bear --append -- make -C tools/testing/vma -j
> 
> Bear generates some temporary files. These are usually deleted again
> but having them show up ephemerally confuses tools that trigger
> recompilation on source code changes. Ignore them in Git so that these
> tools can tell they aren't source code.
> 
> [0]: https://github.com/rizsotto/Bear
> 
> Signed-off-by: Brendan Jackman <jackmanb@google.com>

We can likely take this via the Kbuild tree. I do wonder if this would
be better in a tools/.gitignore file since bear is really only of use
there but I am not sure it matters much.

> ---
>  .gitignore | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/.gitignore b/.gitignore
> index 929054df5212d68a32a1f5ee2b267389fcd1c8db..b07c8c8383bd791e903ce985c14c231cb6928411 100644
> --- a/.gitignore
> +++ b/.gitignore
> @@ -53,6 +53,7 @@
>  *.tar
>  *.xz
>  *.zst
> +*.tmp

Please keep the globs alphabetized.

>  Module.symvers
>  dtbs-list
>  modules.order
> @@ -177,6 +178,9 @@ x509.genkey
>  
>  # Clang's compilation database file
>  /compile_commands.json
> +# Temporary files created by 'bear', a tool used for generating
> +# compile_commands.json for non-Kbuild code.
> +*.events.json

Please rebase this on kbuild-next, as '/' is no longer present in the
compile_commands.json line:

https://git.kernel.org/kbuild/l/kbuild-next

The comment feels a little lengthy compared to the rest of the file but
I am not sure it can really be slimmed down...

I am guessing the pattern cannot be made more specific, as I do wonder
if anyone would introduce files with this pattern but that is why we
have the check in scripts/misc-check, so it is probably not that big of
a deal.

>  
>  # Documentation toolchain
>  sphinx_*/
> 
> ---
> base-commit: fab1beda7597fac1cecc01707d55eadb6bbe773c
> change-id: 20250827-master-23458abb102d
> 
> Best regards,
> -- 
> Brendan Jackman <jackmanb@google.com>
> 
> 

Re: [PATCH] .gitignore: ignore temporary files from 'bear'

[Nicolas Schier]

On Fri, Aug 29, 2025 at 04:38:24PM -0700, Nathan Chancellor wrote:
> Hi Brendan,
> 
> On Wed, Aug 27, 2025 at 08:59:43AM +0000, Brendan Jackman wrote:
> > Bear [0] is a tool for generating compile_commands.json. For Kbuild,
> > Bear is not useful, since Kbuild already generates the necessary info
> > and that can be converted to compile_commands.json by
> > gen_compile_commads.py.
> > 
> > However, for code in tools/, it's handy. For example, this command
> > updates compile_commands.json so that clangd code navigation will also
> > work for the VMA unit tests:
> > 
> > 	bear --append -- make -C tools/testing/vma -j
> > 
> > Bear generates some temporary files. These are usually deleted again
> > but having them show up ephemerally confuses tools that trigger
> > recompilation on source code changes. Ignore them in Git so that these
> > tools can tell they aren't source code.
> > 
> > [0]: https://github.com/rizsotto/Bear
> > 
> > Signed-off-by: Brendan Jackman <jackmanb@google.com>
> 
> We can likely take this via the Kbuild tree. I do wonder if this would
> be better in a tools/.gitignore file since bear is really only of use
> there but I am not sure it matters much.

yeah, please consider using tools/.gitignore.  Please have a look at
this thread about ignoring files from "external" tools:

https://lore.kernel.org/lkml/CAHk-=wiJHMje8cpiTajqrLrM23wZK0SWetuK1Bd67c0OGM_BzQ@mail.gmail.com/

If using tools/.gitignore is not possible, I think the best way for
ignoring files that are not natively related to kernel build tools is to 
update the local ~/.config/git/ignore, as suggested in

https://lore.kernel.org/lkml/CAK7LNAQas0cK7pgi72tYC3yU=ZkQxnr41YYW1mXd-sWiHtG+UA@mail.gmail.com/

compare to:

https://docs.github.com/en/get-started/git-basics/ignoring-files#configuring-ignored-files-for-all-repositories-on-your-computer

Kind regards,
Nicolas

Re: [PATCH] .gitignore: ignore temporary files from 'bear'

[Brendan Jackman]

On Sat Aug 30, 2025 at 7:25 PM UTC, Nicolas Schier wrote:
> On Fri, Aug 29, 2025 at 04:38:24PM -0700, Nathan Chancellor wrote:
>> Hi Brendan,
>> 
>> On Wed, Aug 27, 2025 at 08:59:43AM +0000, Brendan Jackman wrote:
>> > Bear [0] is a tool for generating compile_commands.json. For Kbuild,
>> > Bear is not useful, since Kbuild already generates the necessary info
>> > and that can be converted to compile_commands.json by
>> > gen_compile_commads.py.
>> > 
>> > However, for code in tools/, it's handy. For example, this command
>> > updates compile_commands.json so that clangd code navigation will also
>> > work for the VMA unit tests:
>> > 
>> > 	bear --append -- make -C tools/testing/vma -j
>> > 
>> > Bear generates some temporary files. These are usually deleted again
>> > but having them show up ephemerally confuses tools that trigger
>> > recompilation on source code changes. Ignore them in Git so that these
>> > tools can tell they aren't source code.
>> > 
>> > [0]: https://github.com/rizsotto/Bear
>> > 
>> > Signed-off-by: Brendan Jackman <jackmanb@google.com>
>> 
>> We can likely take this via the Kbuild tree. I do wonder if this would
>> be better in a tools/.gitignore file since bear is really only of use
>> there but I am not sure it matters much.
>
> yeah, please consider using tools/.gitignore.  

I don't believe that works here, because AFAIK clangd assumes a single
compile_commands.json, so while we could git-ignore
tools/compile_commands.json that wouldn't really serve the usecase I
have here with 'bear --append'.

> Please have a look at
> this thread about ignoring files from "external" tools:
>
> https://lore.kernel.org/lkml/CAHk-=wiJHMje8cpiTajqrLrM23wZK0SWetuK1Bd67c0OGM_BzQ@mail.gmail.com/

Hm, I would read the spirit of that thread as not being about things
from 'external tools', rather Linus' objection seems to be that the
_lifetime_ of the mbox files is unrelated to the kernel build. Well, to
be honest the only coherent principle I can get from it is "don't break
Linus' workflow". Which... yeah, is still a pretty valid concern.

> If using tools/.gitignore is not possible, I think the best way for
> ignoring files that are not natively related to kernel build tools is to 
> update the local ~/.config/git/ignore, as suggested in
>
> https://lore.kernel.org/lkml/CAK7LNAQas0cK7pgi72tYC3yU=ZkQxnr41YYW1mXd-sWiHtG+UA@mail.gmail.com/

Given this alternative, and given the fact that I'm ignoring a very
generic suffix in *.tmp (if it was just *.events.json I'd say the
practical risk has gotta be close to nil), I think we could just drop
this unless anyone else pops up with evidence that 'bear' is important
to lots of people or something.

Cheers,
Brendan