Re: [PATCH 2/3] qom: move user_creatable_add_opts logic to vl.c and QAPIfy it

[Markus Armbruster <armbru@redhat.com>]

One more little thing...

Paolo Bonzini <pbonzini@redhat.com> writes:

> Emulators are currently using OptsVisitor (via user_creatable_add_opts)
> to parse the -object command line option.  This has one extra feature,
> compared to keyval, which is automatic conversion of integers to lists
> as well as support for lists as repeated options:
>
>   -object memory-backend-ram,id=pc.ram,size=1048576000,host-nodes=0,policy=bind
>
> So we cannot replace OptsVisitor with keyval right now.  Still, this
> patch moves the user_creatable_add_opts logic to vl.c since it is
> not needed anywhere else, and makes it go through user_creatable_add_qapi.
>
> In order to minimize code changes, the predicate still takes a string.
> This can be changed later to use the ObjectType QAPI enum directly.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[...]
> diff --git a/softmmu/vl.c b/softmmu/vl.c
> index ff488ea3e7..b245e912e5 100644
> --- a/softmmu/vl.c
> +++ b/softmmu/vl.c
> @@ -117,6 +117,7 @@
>  #include "qapi/qapi-commands-block-core.h"
>  #include "qapi/qapi-commands-migration.h"
>  #include "qapi/qapi-commands-misc.h"
> +#include "qapi/qapi-visit-qom.h"
>  #include "qapi/qapi-commands-ui.h"
>  #include "qapi/qmp/qerror.h"
>  #include "sysemu/iothread.h"
> @@ -132,10 +133,16 @@ typedef struct BlockdevOptionsQueueEntry {
>  
>  typedef QSIMPLEQ_HEAD(, BlockdevOptionsQueueEntry) BlockdevOptionsQueue;
>  
> +typedef struct ObjectOption {
> +    ObjectOptions *opts;
> +    QTAILQ_ENTRY(ObjectOption) next;
> +} ObjectOption;
> +

The names feel awkward.

ObjectOption represents a -object option.  Fair enough.

ObjectOptions represents the "options" in its option argument.

Confusing.  Calling the whole thing and one of its parts the same is a
bad idea.

I never liked calling the key=value things in option arguments
"options".  They aren't CLI options, they are optional CLI option
parameters.

I also don't like calling so many different things "object" (QObject,
Object, ObjectOption, ObjectOptions), but that feels out of scope here.

Can we please rename ObjectOptions?

A naming convention for CLI option argument types and boxed QMP command
argument types would be nice.

[...]