Re: [Qemu-devel] [PATCH v12 30/36] qapi: Convert QType into qapi builtin enum type

[Markus Armbruster]

Eric Blake <address@hidden> writes:

> What's more meta than using qapi to define qapi? :)
>
> Convert QType into a full-fledged[*] builtin qapi enum type, so
> that a subsequent patch can then use it as the discriminator
> type of qapi alternate types.  Fortunately, the judicious use of
> 'prefix' in the qapi definition avoids churn to the spelling of
> the enum constants.
>
> To avoid circular definitions, we have to flip the order of
> inclusion between "qobject.h" vs. "qapi-types.h".  Back in commit
> 28770e0, we had the latter include the former, so that we could
> use 'QObject *' for our implementation of 'any'.  But that usage
> also works with only a forward declaration, whereas the
> definition of QObject requires QType to be a complete type.

I figure putting the typedef in include/qemu/typedefs.h would be
simpler.  Didn't think of it when I reviewed v11.

>
> [*] The type has to be builtin, rather than declared in
> qapi/common.json, because we want to use it for alternates even
> when common.json is not included. But since it is the first
> builtin enum type, we have to add special cases to qapi-types
> and qapi-visit to only emit definitions once, even when two
> qapi files are being compiled into the same binary (the way we
> already handled builtin list types like 'intList').  We may
> need to revisit how multiple qapi files share common types,
> but that's a project for another day.
>
> Signed-off-by: Eric Blake <address@hidden>

Patch looks sane.