Re: [Qemu-devel] [PATCH 2/2] qapi: Drop qapi-gen --unmask option

[Eric Blake]

On 07/03/2018 12:51 AM, Markus Armbruster wrote:
> Eric Blake <address@hidden> writes:
>
> > On 07/02/2018 01:48 PM, Markus Armbruster wrote:
> > > Eric Blake <address@hidden> writes:
> > >
> > > > Now that we have useful access to the type name as a comment
> > > > in the generated qapi-introspect.c, we don't need to regenerate
> > > > code with a temporary -u option just to get at type names.

>      # three lines: greeting, output of qmp_capabilities, query-qmp-schema
>      return json.loads(out.split('\n')[2])['return']
>
> This returns an abstract syntax tree, represented in Python the obvious
> way.  I can then explore it in Python, say search for object types with
> certain properties.  For example, commit 2860b2b2cb8:
>
>      Thus, the flaw puts an artificial restriction on the QAPI schema: we
>      can't have potentially empty objects and arrays within
>      BlockdevOptions, except when they're optional and "empty" has the same
>      meaning as "absent".
>
> --> Our QAPI schema satisfies this restriction (I checked), but it's a
>      trap for the unwary, and a temptation to employ awkward workarounds
>      for the wary.  Let's get rid of it.
>
> I checked with a Python script that read the schema as shown above.
> Without -u, I'd have to revert the identifier hiding.  I could certainly
> write some more Python to read the mapping from the generated C, but
> that feels like busy work.

Good argument. Okay, I'm dropping this patch, and tweaking the other 
patch commit message to explain that -u is still useful, even with the 
addition of comment aids.

--
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org