Re: [dpdk-dev] [RFC PATCH 0/4] One versionfile to rule them all...

[Bruce Richardson <bruce.richardson@intel.com>]

On Thu, Mar 07, 2019 at 12:09:44PM +0000, Luca Boccassi wrote:
> On Thu, 2019-03-07 at 11:54 +0000, Bruce Richardson wrote:
> > Right now with DPDK we have two sources of version information - the
> > rte_version.h header file containing macros for C use, and the project
> > version number in the project definition in meson.build. This is not
> > optimal, so this patchset aims to provide a single source for the DPDK
> > version. The options considered are:
> > 
> > * Keep version info in rte_version.h only. The two reasons this was not
> > chosen were: 1) parsing the version number from the header is awkward,
> > as seen in the rte.sdkconfig.mk file, and a script to do so would be
> > needed to integrate that into the meson build project definition.  2)
> > rte_version.h is not in an obvious location inside the project when a
> > user clones from git. It's hidden away in the
> > "lib/librte_eal/common/include" folder. Ideally the version number
> > should be evident at the top level of the DPDK tree.
> > 
> > * Keep version info in meson.build file only. This seemed a better
> > option than keeping the info in rte_version.h, but it still had
> > disadvantages: 1) For make, using grep on meson.build to extract the
> > version seemed a bit awkward, though doable. Splitting the version was
> > tricky too, but managable with a small amount of scripting.  2) There
> > was no easy way to have users access the version number when "make
> > showversion" was deprecated with the make build system.
> > 
> > * Store the version number in a new version file at the root level of
> > the repo.  * This did have the advantage of being easily discoverable
> > on clone * Still had the disadvantage of needing some parsing to
> > generate the defines from rte_version.h
> > 
> > Since the last option seemed best, that is what is implemented in this
> > set.  The file DPDK_VERSION is added to store the version number, and
> > make and meson both use that as their source of version info. For C
> > code, the rte_version.h header remains, except that the basic
> > definitions of the release YEAR, MONTH, MINOR etc. are moved to be
> > automatically generated as part of rte_config.h. For make builds, this
> > is done via using the preprocessor to insert the values when it
> > generates the config. For meson builds, this is done by just adding the
> > values to the dpdk_conf configuration object.
> > 
> > Bruce Richardson (4): build: add single source of DPDK version number
> > build: use version number from config file build: move meson version
> > handling to config directory eal: remove unneeded version logic
> > 
> >  DPDK_VERSION                                |  1 + config/common_base
> >  | 14 ++++++++ config/meson.build                          | 26
> >  +++++++++++++++ config/rte_config.h                         |  5 +++
> >  lib/librte_eal/common/include/rte_version.h | 36 +----------------
> >  ---- meson.build                                 | 14 +-------
> >  mk/rte.sdkconfig.mk                         | 18 +++-------- 7 files
> >  changed, 52 insertions(+), 62 deletions(-) create mode 100644
> >  DPDK_VERSION
> 
> Series-acked-by: Luca Boccassi <bluca@debian.org>
> 
> This is a good change, thanks for that. Too bad there's not yet a meson
> --project-version option - it's been discussed but not implemented:
> 
> https://github.com/mesonbuild/meson/issues/3535
> 
Yes, I saw that request, and considered looking into doing it. However,
even when it is implemented, we wouldn't be able to base anything on it
till our next meson version bump at the earliest. Therefore I felt the most
effective solution is one based in DPDK itself.