Re: [PATCH 1/6] writer: Emit definitions of declarations when they are present

[Giuliano Procida <gprocida@google.com>]

Hi.

On Mon, 30 Nov 2020 at 15:56, Dodji Seketeli <dodji@redhat.com> wrote:

> Hello Giuliano,
>
> Giuliano Procida via Libabigail <libabigail@sourceware.org> a écrit:
>
> > Hi Dodji.
> >
> > I had a quick scan through this.
> >
> > Do we need  look_through_decl_only_enum  somewhere as well?
>
> Good question.
>
> Right now, when the equals function compares enums, it doens't look
> through the declaration to get the definition of the enum.  It will only
> use the decl-only part of the enum in the comparison, even if the enum
> decl was fully resolved to its definition.  For classes (and unions)
> however, equals always looks through the declaration.
>
> So, at ABIXML write time, if we happen to not saving the definition and
> we only save the decl-only part, the comparison should be done between
> the decl-only part of both enums (the one in the IR coming from the
> binary and the one from the IR coming from the ABIXML) being compared.
> So it shouldn't yield an ABI change.
>
> Now, the behaviour for classes/unions can be said to be inconsistent with
> the behaviour for enums.  So we might indeed want to always serialize
> the definition of declarations of enum if we have it.
>
> But then, we'd need update at least the 'equals' comparison function
> accordingly, I believe.
>
> But as this is like getting into the "feature" territory (kind of) I'd
> wait for releasing 1.8 before doing this.
>
> What do you think?
>
>
I agree. TBH, in retrospect, all the forward-declared enum changes could
have waited. I can paste your comment into Bugzilla, but you might prefer
something else.

Regards,
Giuliano.

> [...]
>
> Cheers,
>
>
> --
>                 Dodji
>
>