Re: [PATCH v4] devtools: add .clang-format file

[Stephen Hemminger <stephen@networkplumber.org>]

On Wed, 15 May 2024 09:43:22 +0100
Bruce Richardson <bruce.richardson@intel.com> wrote:

> On Wed, May 15, 2024 at 11:28:33AM +0300, Abdullah Ömer Yamaç wrote:
> >    I want to update you.
> >    On Mon, May 13, 2024 at 4:08 PM Ferruh Yigit <[1]ferruh.yigit@amd.com>
> >    wrote:
> > 
> >      On 5/8/2024 10:19 PM, Abdullah Ömer Yamaç wrote:  
> >      > clang-format is a tool to format C/C++/Objective-C code. It can be  
> >      used  
> >      > to reformat code to match a given coding style, or to ensure that  
> >      code  
> >      > adheres to a specific coding style. It helps to maintain a  
> >      consistent  
> >      > coding style across the DPDK codebase.
> >      >
> >      > .clang-format file overrides the default style options provided by
> >      > clang-format and large set of IDEs and text editors support it.
> >      >
> >      > Signed-off-by: Abdullah Ömer Yamaç <[2]aomeryamac@gmail.com>
> >      >  
> >      Hi Omer,
> >      I tried on ethdev.c (clang-format -i ./lib/ethdev/rte_ethdev.c), I
> >      will
> >      highlight a few issues below (not all of them), I hope it is OK to
> >      continue step by step, fixing these issues.
> >      1. clang format failed for following options, not sure why, am I
> >      using a
> >      wrong version:
> >      LineEnding: LF
> >      InsertNewlineAtEOF: true
> >      I commented them out to continue the test.
> >      And for 'ColumnLimit', I prefer default 80 with the flexibility to
> >      go
> >      100 when makes sense, so I will got with 'ColumnLimit: 80'; but I
> >      don't
> >      want to start this discussion.
> > 
> >    In the .editorconfig file, 100 is stated as a max_line_length. That's
> >    why I prefer 100.
> >   
> 
> +1 for keeping as 100
> 
> >      2. Double tab indentation vs parenthesis align
> >               if (iter->bus != NULL &&
> >       -                       /* not in middle of rte_eth_dev iteration,
> >      */
> >       -                       iter->class_device == NULL) {
> >       +           /* not in middle of rte_eth_dev iteration, */
> >       +           iter->class_device == NULL) {
> >      DPDK coding guide suggests double tab, but also accepts alignment by
> >      spaces. But as far as I can see most of code has double tab.
> >      Majority of the diff caused because of this rule.
> > 
> >    Still, some discussions are going on
> >   
> 
> This is one where I don't think we will were reach a consensus, and even if
> we did, it would mean massive churn to DPDK. Can we have clang-format NOT
> adjust line-continuations in a file?


Clang format is useful on new and seriously broken code.
Do not want to do it automatically or accept patches across all the current code.

For indentation, can we get some setting that matches what DPDK double tab does?
If not is there something close. Often useful to look at the other clang format
pre-set styles in source.