[dpdk-dev] [PATCHv3 0/4] dpdk: enhance EXPERIMENTAL api tagging

[Neil Horman]

On Sat, Dec 30, 2017 at 12:15:17PM -0500, Neil Horman wrote:
> On Tue, Dec 12, 2017 at 02:07:52PM +0000, Bruce Richardson wrote:
> > On Mon, Dec 11, 2017 at 02:36:15PM -0500, Neil Horman wrote:
> > > Hey all-
> > > 	A few days ago, I was lamenting the fact that, when reviewing patches I
> > > would frequently complain about ABI changes that were actually considered safe
> > > because they were part of the EXPERIMENTAL api set.  John M. asked me then what
> > > I might do to improve the situation, and the following patch set is a proposal
> > > that I've come up with.
> > > 
> > > 	In thinking about the problem I identified two issues that I think we
> > > can improve on in this area:
> > > 
> > > 1) Make experimental api calls more visible in the source code.  That is to say,
> > > when reviewing patches, it would be nice to have some sort of visual reference
> > > that indicates that the changes being made are part of an experimental API and
> > > therefore ABI concerns need not be addressed
> > > 
> > > 2) Make experimenal api usage more visible to consumers of the DPDK, so that
> > > they can make a more informed decision about the API's they consume in their
> > > application.  We make an effort to document all the experimental API's, but
> > > there is no guarantee that a user will check the documentation before making use
> > > of a new library.
> > > 
> > > This patch set attempts to achieve both of the above goals.  To do this I've
> > > added an __experimental macro tag, suitable for inserting into api forward
> > > declarations and definitions.
> > > 
> > > The presence of the tag in the header and c files where the api code resides
> > > increases the likelyhood that any patch submitted against them will include the
> > > tag in the context, making it clear to reviewers that ABI stability isn't a
> > > concern here.
> > > 
> > > 
> > > Also, This tag marks each function it is used on with an attibute causing any
> > > use of the fuction to emit a warning during the build
> > > with a message indicating that the API call in question is not yet part of the
> > > stable interface.  Developers can then make an informed decision to suppress
> > > that warning or not.
> > > 
> > > Because there is internal use of several experimental API's, this set also
> > > includes a new override macro ALLOW_EXPERIMENTAL_APIS to automatically
> > > suprress these warnings.  I think its fair to assume that, for internal use, we
> > > almost always want to suppress these warnings, as by definition any change to
> > > the apis (even their removal) must be done in parallel with an appropriate
> > > change in the calling locations, lest the dpdk build itself break.
> > > 
> > > Neil
> > > 
> > > ---
> > > Change Notes:
> > > v2)
> > > * Cleaned up checkpatch errors
> > > * Added Allowance for building experimental on BSD
> > > * Swapped Patch 3 and 4 so that we didn't have a commit level that issued
> > >   warnings/errors without need
> > > 
> > > v3)
> > > * On suggestion from Bruce, modify ALLOW_EXPERIMENTAL_APIS to be defined in
> > >   CFLAGS rather than a makefile variable.  This is more flexible in that it
> > >   allows us to suppress this specific feature rather than all uses of the 
> > >   deprecated attribute, as we might use it for other features in the furute
> > > 
> > 
> > Despite the fact that this is making yet more work for porting to a new
> > build system, I think this is a good idea to have. As such,
> > 
> > Acked-by: Bruce Richardson <bruce.richardson at intel.com>
> > 
> > 
> 
> Thomas-
>      I just noticed that the ci tests are failing on the intel compiler, which
> makes very little sense to me, as the error is a permission error on a bash
> script that added in this series, which works during the gcc compilation.  Can
> you take a look at that please?
> 
> thanks
> Neil
> 
Ping again Thomas, I've still heard nothing from you or the CI group about
getting more visibility into the odd permission problem in the CI runs this
seems to be encountering.  I'd love to fix it, but the information in the report
is insufficient to have any idea whats going on and the problem does not occur
on local builds.  Please advise.

Neil