[dpdk-dev] [PATCH v2 16/19] app/chkincs: add chkincs app to verify headers

[Bruce Richardson]

On Fri, Jan 15, 2021 at 02:59:08PM +0000, Bruce Richardson wrote:
> On Fri, Jan 15, 2021 at 02:55:41PM +0000, Bruce Richardson wrote:
> > On Fri, Jan 15, 2021 at 03:09:25PM +0100, Thomas Monjalon wrote:
> > > 15/01/2021 12:59, Bruce Richardson:
> > > > On Fri, Jan 15, 2021 at 11:51:49AM +0000, Ferruh Yigit wrote:
> > > > > On 1/15/2021 11:10 AM, Bruce Richardson wrote:
> > > > > > To verify that all DPDK headers are ok for inclusion directly in a C
> > > > > > file, and are not missing any other pre-requisite headers, we can
> > > > > > auto-generate for each header an empty C file that includes that header.
> > > > > > Compiling these files will throw errors if any header has unmet
> > > > > > dependencies.
> > > > > > 
> > > > > > The list of headers to check is based of the "headers" value returned from
> > > > > > each library's meson.build file. However, since not all headers are for
> > > > > > direct inclusion, add a build variable "headers_no_chkincs" to list those
> > > > > > headers and skip checking them.
> > > > > > 
> > > > > > Signed-off-by: Bruce Richardson <bruce.richardson at intel.com>
> > > > > > ---
> > > > > > 
> > > > > > v2:
> > > > > > * add maintainers entry
> > > > > > * distribute exception list among meson.build files.
> > > > > > 
> > > > > >   MAINTAINERS                              |  4 ++++
> > > > > >   app/chkincs/gen_c_file_for_header.py     | 12 ++++++++++
> > > > > >   app/chkincs/main.c                       |  4 ++++
> > > > > >   app/chkincs/meson.build                  | 28 ++++++++++++++++++++++++
> > > > > 
> > > > > +1 to have this kind of tool to check, but it is not an application like
> > > > > others in the 'app' folder, what do you think placing it under 'devtools' or
> > > > > 'buildtools'?
> > > > 
> > > > Couple of reasons why it's placed in app.
> > > > 
> > > > 1. We previously had a "chkincs" app in DPDK which was kept in the app
> > > > folder
> > > > 2. It allows us to reuse the build infrastructure for building apps, rather
> > > > than reduplicating it.
> > > > 3. We don't have any compilable code currently in the devtools folder, and
> > > > even in buildtools the pmdinfogen app is going to go away.
> > > > 
> > > > That being said, none of those reasons are major issues that can't be
> > > > worked around if the consensus is to move it.
> > > 
> > > It could be easily in devtools if it was a script.
> > > By the way, we already have devtools/check-includes.sh
> > > If your solution is better, please remove this script.
> > > 
> > I only discovered the script existed when doing the v2 of this patchset,
> > since it showed up in some grep calls I did for exception cases. I'm not
> > sure that either approach is necessarily better, it's just right now that
> > the script is unused (and also unknown) which is why I did this cleanup
> > work.
> > 
> > Here is how I see the current comparison between two approaches:
> > * Script as advantage in that it performs C++ checks as well as C
> > * Script also allows passing arbitrary additional C flags into checks for
> >   higher levels of compliance, but I'm not sure this is something I like as
> >   I'd rather have standardisation here across all headers than have some
> >   headers more pedantic-friendly than others.
> > * Main downside of the script is that is works off directories rather than
> >   a list of files, which means it requires maintenance of the exception
> >   list in the script, rather than in the build definition files where we call
> >   out the headers to be installed
> > 
> > I'm honestly fine either way on this (as with directory where
> > implementation lives) - main thing is to have the checking done, rather
> > than ignored.
> > 
> And I (obviously) forgot to mention that the existing script is not currently
> integrated into existing build or build-test scripts. I haven't looked into
> how complex this would be, but it would require investigation time.

I do plan to look into re-using the script and other options around this
area - hopefully in RC2 timeframe. However, to make the patchset rework a
little easier, perhaps the small header fixes could be picked up for ahead
of any rework?

/Bruce