Re: [Qemu-devel] [PATCH v5 13/14] qapi: Allow anonymous base for flat union

[Markus Armbruster]

Eric Blake <address@hidden> writes:

> Rather than requiring all flat unions to explicitly create
> a separate base struct, we can allow the qapi schema to specify
> the common members via an inline dictionary. This is similar to
> how commands can specify an inline anonymous type for its 'data'.
> We already have several struct types that only exist to serve as
> a single flat union's base; the next commit will clean them up
> (in particular, the doc change to the BlockdevOptions example in
> this patch will be reflected to QMP in the next).

The parenthesis is a bit cryptic.  "Reflected"?

> Now that anonymous bases are legal, we need to rework the
> flat-union-bad-base negative test (as previously written, it
> forms what is now valid QAPI; tweak it to now provide coverage
> of a new error message path), and add a positive test in
> qapi-schema-test to use an anonymous base (making the integer
> argument optional, for even more coverage).
>
> Note that this patch only allows anonymous bases for flat unions;
> simple unions are already enough syntactic sugar that we do not
> want to burden them further.  Meanwhile, while it would be easy
> to also allow an anonymous base for structs, that would be quite
> redundant, as the members can be put right into the struct
> instead.
>
> Signed-off-by: Eric Blake <address@hidden>

Patch looks good.