Re: [dpdk-dev] [EXT] Re: [PATCH v10 1/4] devtools: add exception for reserved fields

[Akhil Goyal <gakhil@marvell.com>]

Hi David,
> > Certain structures are added with reserved fields
> > to address any future enhancements to retain ABI
> > compatibility.
> > However, ABI script will still report error as it
> > is not aware of reserved fields. Hence, adding a
> > generic exception for reserved fields.
> >
> > Signed-off-by: Akhil Goyal <gakhil@marvell.com>
> > ---
> >  devtools/libabigail.abignore | 6 +++++-
> >  1 file changed, 5 insertions(+), 1 deletion(-)
> >
> > diff --git a/devtools/libabigail.abignore b/devtools/libabigail.abignore
> > index 6c0b38984..654755314 100644
> > --- a/devtools/libabigail.abignore
> > +++ b/devtools/libabigail.abignore
> > @@ -19,4 +19,8 @@
> >  ; Ignore fields inserted in cacheline boundary of rte_cryptodev
> >  [suppress_type]
> >          name = rte_cryptodev
> > -        has_data_member_inserted_between = {offset_after(attached), end}
> > \ No newline at end of file
> > +        has_data_member_inserted_between = {offset_after(attached), end}
> > +
> > +; Ignore changes in reserved fields
> > +[suppress_variable]
> > +       name_regexp = reserved
> Mm, this rule is a bit scary, as it matches anything with "reserved" in it.

Why do you feel it is scary? Reserved is something which may change at any time
Just like experimental. Hence creating a generic exception rule for it make sense
And it is done intentionally in this patch.

> 
> You need an exception anyway to insert the new fields (like in patch 2).
> Can you test your series dropping this patch 1 ?
It will not work, as there are 2 changes,
1. addition of ca_enqueue after attached. This is taken care by the exception set in patch 2
2. change in the reserved_ptr[4] -> reserved_ptr[3]. For this change we need exception for reserved.

Regards,
Akhil