# Re: [PATCH] Set git diff driver for C source code files.

1 messages from 2022-10-25 to 2022-10-25. Participants: Alejandro Colomar.
Thread: https://gitlist.dev/t/58689

## Alejandro Colomar, 2022-10-25 19:26

Subject: Re: [PATCH] Set git diff driver for C source code files.
Message-ID: <242e6a00-a2ad-4b7b-3643-41cf49d4432a@gmail.com>
URL: https://gitlist.dev/e/242e6a00-a2ad-4b7b-3643-41cf49d4432a%40gmail.com
In-Reply-To: <20221025191552.60658-1-a.clayton@nginx.com>

```
Hi Andrew,

On 10/25/22 21:15, Andrew Clayton wrote:
> Git can be told to apply language-specific rules when generating diffs.
> Enable this for C source code files (*.c and *.h) so that function names
> are printed right. Specifically, doing so prevents "git diff" from
> mistakenly considering unindented goto labels as function names.
> 
> This has the same effect as adding
> 
>      [diff "default"]
>          xfuncname = "^[[:alpha:]$_].*[^:]$"

Where does that regex come from?

> 
> to your git config file.
> 
> e.g get
> 
>      @@ -10,7 +10,7 @@ int main(void)
> 
> instead of
> 
>      @@ -10,7 +10,7 @@ again:
> 
> This makes use of the gitattributes(5) infrastructure.
> 
> Signed-off-by: Andrew Clayton <a.clayton@nginx.com>

Wow!  git(1) is showing C functions incorrectly?!  The last language I expected 
this to happen with.  I had to use this for man(7) pages, but for C files?!

I mean, we have one of the simplest and most consistent coding styles I've seen 
regarding placement of function definitions (no false negatives or positives in 
grepc(1)).

Should we report a bug to <mailto:Git <git@vger.kernel.org>> too :)

> ---
>   .gitattributes | 2 ++
>   1 file changed, 2 insertions(+)
>   create mode 100644 .gitattributes
> 
> diff --git a/.gitattributes b/.gitattributes
> new file mode 100644
> index 00000000..45ec5156
> --- /dev/null
> +++ b/.gitattributes
> @@ -0,0 +1,2 @@
> +*.c	diff=cpp
> +*.h	diff=cpp

Why cpp?

Thanks,

Alex

-- 
<http://www.alejandro-colomar.es/>

```